JP2019127940A - Ignition device and internal combustion engine - Google Patents

Abstract

To provide a laser device capable of reducing the flow velocity of an air-fuel mixture around an ignition point and improving the stability of ignition.
An igniter is an igniter for igniting fuel contained in an air-fuel mixture supplied to a main combustion chamber of an internal combustion engine, and forms an auxiliary combustion chamber surrounding an ignition point of the fuel. A partition member provided with a plurality of communication holes communicating the main combustion chamber and the preliminary combustion chamber, and a first interference member provided to project inward from the inner surface of the partition member .
[Selected figure] Figure 2

Description

  The present invention relates to an ignition device and an internal combustion engine.

Recently, the generator engine cogeneration system (cogeneration system), it is required in terms of reduction and NO _X reduction in CO _2, is more efficient. In order to achieve high efficiency of the engine, it is necessary to be able to stably burn the fuel in the lean mixture by the engine under high supercharging, high compression, and ultra lean conditions.

  When igniting by spark ignition in a high-supercharged, high-compression, ultra-lean engine, the in-cylinder pressure before ignition is high and it is ultra-lean, greatly increasing the energy supplied to the spark plug. There is a need. As an igniter used for such an engine, there is, for example, a pre-chamber plug which burns a lean mixture more efficiently by using a pre-chamber which is a pre-combustion chamber.

  As such a pre-chamber plug, for example, there is an ignition plug that ignites an air / fuel mixture existing in the inner chamber of the pre-chamber by causing laser radiation to enter the inner chamber of the pre-chamber from a laser spark plug provided in the cylinder head. (For example, refer to Patent Document 1).

  However, since the conventional ignition device has a pre-chamber, the air-fuel mixture flows from the main combustion chamber toward the inside of the pre-chamber through the pre-chamber hole that connects the inside of the pre-chamber and the engine main combustion chamber in the compression stroke of the engine. . Due to the inflow of the air-fuel mixture to the inside of the pre-chamber, the flow rate of the air-fuel mixture in the pre-chamber increases. For this reason, when there is an ignition point in a region where the flow rate of the air-fuel mixture is fast, the initial flame generated by the ignition is likely to be extinguished, so that there is a possibility that the fuel cannot be ignited steadily in the combustion chamber.

  An aspect of the present invention aims to provide an igniter capable of reducing the flow rate of the air-fuel mixture at the ignition point and the surrounding area, and enhancing the stability of the ignition.

  An ignition device according to an aspect of the present invention is an ignition device for igniting fuel contained in an air-fuel mixture supplied to a main combustion chamber of an internal combustion engine, and forms a precombustion chamber surrounding the ignition point of the fuel. A partition member provided with a plurality of communication holes communicating with the main combustion chamber and the preliminary combustion chamber, a first interference member provided to protrude inward from the inner surface of the partition member, Have

  The igniter in accordance with one aspect of the present invention can reduce the flow velocity of the ignition point and the mixture around it, and can enhance the stability of the ignition.

It is sectional drawing which shows an internal combustion engine provided with the ignition device which concerns on 1st Embodiment. It is a front view which shows the structure of a pre-chamber cap when the ignition device which concerns on 1st Embodiment is seen from the main combustion chamber side. It is 1A-1A sectional drawing shown in FIG. It is explanatory drawing which shows the state in which the ignition flame has generate | occur | produced. It is a front view which shows the structure of a pre-chamber cap when the ignition device which concerns on 2nd Embodiment is seen from the main combustion chamber side. It is 2A-2A sectional drawing shown in FIG. It is 2B-2B sectional drawing shown in FIG. It is a front view which shows the structure of a pre-chamber cap when the ignition device which concerns on 3rd Embodiment is seen from the main combustion chamber side. It is 3A-3A sectional drawing shown in FIG. It is 3B-3B sectional drawing shown in FIG. It is a front view which shows the structure of a pre-chamber cap when the ignition device which concerns on 4th Embodiment is seen from the main combustion chamber side. It is 4A-4A sectional drawing shown in FIG. It is 4B-4B sectional drawing shown in FIG. It is a front view which shows the structure of a pre-chamber cap when the ignition device which concerns on 5th Embodiment is seen from the main combustion chamber side. It is 5A-5A sectional drawing shown in FIG. It is 5B-5B sectional drawing shown in FIG. It is 5C-5C sectional drawing shown in FIG. It is a front view which shows the structure of a pre-chamber cap when the ignition device which concerns on 6th Embodiment is seen from the main combustion chamber side. It is 6A-6A sectional drawing shown in FIG. It is 6B-6B sectional drawing shown in FIG. It is 6C-6C sectional drawing shown in FIG. It is 6D-6D sectional drawing shown in FIG. It is a front view which shows the structure of a pre-chamber cap when the ignition device which concerns on 7th Embodiment is seen from the main combustion chamber side. It is 7A-7A sectional drawing shown in FIG. It is 7B-7B sectional drawing shown in FIG. It is 7C-7C sectional drawing shown in FIG. It is 7D-7D sectional drawing shown in FIG. It is 7E-7E sectional drawing shown in FIG. It is a front view which shows the structure of a pre-chamber cap when the ignition device which concerns on 8th Embodiment is seen from the main combustion chamber side. It is 8A-8A sectional drawing shown in FIG. It is 8B-8B sectional drawing shown in FIG. It is 8C-8C sectional drawing shown in FIG. It is 8D-8D sectional drawing shown in FIG. It is 8E-8E sectional drawing shown in FIG. It is a front view which shows the structure of a pre-chamber cap when the ignition device which concerns on 9th Embodiment is seen from the main combustion chamber side. It is 9A-9A sectional drawing shown in FIG.

  Hereinafter, the embodiment will be described in detail.

[First Embodiment]
The case where the ignition device according to the first embodiment is applied to an internal combustion engine will be described with reference to the drawings. In the present embodiment, the case of using a gas engine for power generation as an internal combustion engine will be described.

<Internal combustion engine>
FIG. 1 is a cross-sectional view showing an internal combustion engine provided with the ignition device according to the first embodiment. In this specification, a three-dimensional orthogonal coordinate system in three axis directions (X axis direction, Y axis direction, Z axis direction) is used. In the plane orthogonal to the optical axis of the laser beam, the laser beam emission direction from the light source of the laser device is the + Z direction, and one of the two directions orthogonal to each other is the X axis direction, and the other is the Y axis direction. .

  As shown in FIG. 1, an internal combustion engine (engine) 10 has an ignition device 11A, a cylinder head 12, a cylinder 13, a piston 14, an intake port 15, an exhaust port 16, an intake valve 17, and an exhaust valve 18. A main combustion chamber 19 of the engine 10 is formed in the cylinder 13 by being surrounded by the igniter 11A, the cylinder head 12, the piston 14, the intake valve 17 and the exhaust valve 18.

  The tip of the ignition device 11A is provided on the cylinder head 12 so as to protrude toward the main combustion chamber 19 side. The ignition device 11A includes a laser device 21, a window member 22, a housing (housing) 23, a pre-chamber cap (partition member) 24A, and a first interference member 25A. The air-fuel mixture supplied into the main combustion chamber 19 passes through the plurality of communication holes (prechamber holes) 241 of the prechamber cap 24A from the main combustion chamber 19, and the precombustion chamber 26, which is a prechamber inside the prechamber cap 24A. To be supplied. The laser beam LB is irradiated into the air-fuel mixture supplied to the preliminary combustion chamber 26 to condense the laser beam LB. The fuel in the air-fuel mixture is ignited by generating a plasma with the focusing point of the laser beam LB as an ignition point (breakdown point) BP. Details of the ignition device 11A will be described later.

  The cylinder head 12 is formed by a cylinder block which is a molded product made of iron or aluminum alloy.

  The cylinder 13 is a cylindrical metal member having a bottom and has a plurality of openings for receiving the ignition device 11A, the intake valve 17, and the exhaust valve 18. In the operating state, the intake valve 17 and the exhaust valve 18 open so that air and fuel are supplied into the main combustion chamber 19 at a predetermined ratio.

  The piston 14 is connected to a crankshaft (not shown) and a connecting rod (not shown), and reciprocates by the rotation of the crankshaft.

  The ignition device 11A, the intake valve 17 and the exhaust valve 18 are electrically connected to a drive device (not shown) provided outside the engine 10, and the ignition device 11A is based on an instruction of a control device (not shown). Controlled by the driving device.

  The operation of the engine 10 will be briefly described. The intake valve 17 ascends in the intake port 15 to eject a combustible mixture including fuel and air from the intake port 15 into the main combustion chamber 19 (intake process). Thereafter, the piston 14 ascends to compress the mixture (compression step). The compressed air-fuel mixture in the main combustion chamber 19 is supplied into the preliminary combustion chamber 26 of the igniter 11A. The igniter 11A condenses the laser light emitted from the laser device 21 into the supplied air-fuel mixture to generate plasma. The generated plasma ignites the fuel in the mixture (ignition). In the preliminary combustion chamber 26, the air-fuel mixture is pre-combusted by ignition of fuel. Then, the mixture pre-combusted in the pre-combustion chamber 26 is ejected from the pre-chamber hole 241 of the pre-chamber cap 24A into the main combustion chamber 19 as an ignition flare (point flame). The combustion gas in the main combustion chamber 19 is expanded by igniting the fuel in the mixture of the main combustion chamber 19 and performing main combustion. Thereby, piston 14 falls (combustion process). Thereafter, the exhaust valve 18 ascends the exhaust port 16 and exhausts the combustion gas from the main combustion chamber 19 through the exhaust port 16 (exhaust process).

  As described above, in the engine 10, a series of processes is repeated, with four processes including the intake process, the compression process, the combustion process, and the exhaust process being one cycle. Then, the piston 14 moves in response to the volume change of the gas in the main combustion chamber 19 to generate kinetic energy. For example, natural gas or city gas is used as the fuel.

  The emission of laser light in the ignition device 11A is controlled by a drive device (not shown) based on an instruction of a control device (not shown). The intake valve 17 and the exhaust valve 18 are operated at an appropriate timing for four strokes by a device not shown.

  The engine 10 is a four-stroke engine, but may be a two-stroke engine.

<Ignition device>
The ignition device 11A will be described. The configuration of the ignition device 11A is shown in FIG. 2 and FIG. 2 is a front view showing the configuration of the pre-chamber cap 24A when the igniter according to this embodiment is viewed from the main combustion chamber 19 side, and FIG. 3 is a cross-sectional view taken along 1A-1A shown in FIG. . In addition, the dashed-dotted line in FIGS. 1-5 shows the centerline (center axis) J of the longitudinal direction (Z-axis direction) of 11 A of ignition devices. The central axis J coincides with the optical axis of the laser light emitted from the laser device, and is also the central axis of the laser device.

  As shown in FIGS. 2 and 3, the igniter 11A includes a laser device 21, a window member 22, a housing 23, a pre-chamber cap 24A, and a first interference member 25A. A pre-chamber (pre-combustion chamber) 26 is formed inside the pre-chamber cap 24A.

  The laser device 21 has a light source for emitting a laser beam and a focusing optical system for focusing the laser beam. The laser device 21 condenses the laser beam LB emitted from the light source into the preliminary combustion chamber 26. The laser device 21 is disposed such that the axis in the longitudinal direction (Z-axis direction) is parallel to the reciprocating direction (Z-axis direction) of the piston 14 (see FIG. 1).

  As the light source, for example, a semiconductor laser such as a surface emitting laser or an edge emitting laser can be used. Among these, it is preferable to use a surface emitting laser as the light source. The surface emitting laser is a light source for excitation and has a plurality of light emitting units. Each light emitting unit is a vertical cavity surface emitting laser (VCSEL: Vertical Cavity Surface Emitting Laser). The wavelength of the laser light emitted from the surface emitting laser is, for example, about 808 nm. A surface emitting laser has a very small wavelength shift due to temperature of emitted laser light. Therefore, a surface emitting laser is a light source advantageous for increasing the energy density of laser light with a Q switch type laser resonator whose characteristics largely change due to wavelength shift. The surface emitting laser is electrically connected to a driving device (not shown), and the surface emitting laser is driven based on an instruction from an engine control device (not shown) to emit laser light from the surface emitting laser.

  The condensing optical system has at least one condensing lens. An appropriate condenser lens is selected according to the cross-sectional area of the laser beam and the like. The condensing optical system condenses the laser light LB emitted from the light source.

  The condensing optical system may include, in addition to the condensing lens, a concave lens that diverges laser light and a collimator lens that collimates the laser light. Further, the focusing optical system may have another optical element such as an optical fiber or a Q switch type laser resonator.

  The condensing optical system includes an optical fiber, so that the laser light emitted from the light source can be incident on one end of the optical fiber and can be emitted from the other end. Therefore, the laser beam can be emitted from an arbitrary place via one end of the optical fiber, so that the degree of freedom in the arrangement of the light source and the condensing optical system is increased. Moreover, since the light source can be kept away from the high temperature area around the engine 10 (see FIG. 1), the width of the method of cooling the engine 10 can be expanded. Furthermore, since the light source can be provided at a distance from the engine 10 (see FIG. 1) which is a vibration source, blurring of the laser light emitted from the light source can be prevented.

  The condensing optical system includes a Q-switch type laser resonator, so that the energy density of laser light incident on the laser resonator is increased, and laser light having a wavelength of, for example, about 1064 nm is emitted with a short pulse width. Can do. The energy density of the laser light is increased by resonating and amplifying the laser light incident on the laser resonator in the laser resonator. When the amount of laser light absorption is saturated, Q-switch oscillation occurs. As a result, a laser beam with a high energy density is emitted from the laser resonator with its energy concentrated at a short pulse width. In addition, when a condensing optical system is equipped with a laser resonator, the laser beam which injects into a laser resonator is also called "excitation light." Laser light emitted from the laser resonator is also referred to as pulsed laser light. The wavelength of the pulse laser beam is, for example, about 1064 nm.

  The laser device 21 can obtain a high energy density at the focusing point by focusing the laser light by the focusing optical system. When the focused laser beam LB exceeds a certain energy density, molecules constituting the gas in the mixture in the precombustion chamber 26 are ionized, separated into cations and electrons, and converted into plasma (break) Down).

  As shown in FIG. 3, the window member 22 includes an optical window 221 and an optical window holding member 222. The laser beam LB emitted from the condensing optical system passes through the optical window 221 and is condensed in the preliminary combustion chamber 26.

  The optical window 221 is disposed on the light path of the laser beam LB emitted from the laser device 21 as shown in FIG.

  The shape in plan view of the optical window 221 is not particularly limited, and may be, for example, a rectangular shape, a circular shape, an elliptical shape, a rectangular shape, or a polygonal shape.

  The optical window 221 is made of a transparent or translucent material. As a material of the optical window 221, optical glass, heat-resistant glass, quartz glass, sapphire glass etc. can be used, for example. In particular, since the optical window 221 protects the optical members and the like inside the housing 23 from the combustion pressure generated in the preliminary combustion chamber 26, it needs a sufficient pressure resistance. As a material of the optical window 221, it is preferable to use sapphire glass having excellent durability under a high temperature and high pressure environment even if the thickness of the optical window 221 is thin.

  The optical window 221 may have an anti-reflection (AR: Anti Reflection) film (AR film) on the incident surface through which the laser light passes. The antireflection film is a film that is provided on the incident surface of the optical window 221 and suppresses reflection of laser light. The antireflective film has high transmittance to laser light having a wavelength of 1064 nm.

  As a material for forming the antireflective film, for example, Si, Na, Al, Ca, Mg, B, C, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Sr, A material mainly containing any one of Zr, Nb, Ru, Pd, Ag, In, Sn, Hf, Ta, W, Ot, Au, and Bi, or a nitride, oxide, carbide, and A material containing at least one of fluorides can be used. As a method for forming the antireflective film on the optical window 221, for example, vapor deposition, sputtering, thermal spraying, coating, or a sol-gel method can be used. The antireflection film may be a single layer or a multilayer.

  The optical window holding member 222 is fixed to the inner surface of the housing 23 as shown in FIG. The optical window holding member 222 can be fixed to the inner surface of the housing 23 by welding, screwing, shrink fitting, bonding or the like.

  The optical window holding member 222 can fix and hold the optical window 221 by brazing using a brazing material as a bonding material on its inner surface. In addition to the brazing material, another bonding material having heat resistance at high temperature may be used as the bonding material. Alternatively, the optical window 221 may be fixed to the optical window holding member 222 by screwing or shrink fitting without using a bonding material.

  As a material for forming the optical window holding member 222, for example, a heat-resistant metal material such as iron, nickel, a Ni—Fe alloy, a Ni—Cr—Fe alloy, a Ni—Co—Fe alloy, or stainless steel is used. Can do. Examples of the Ni—Cr—Fe alloy include inconel. Examples of the Ni—Co—Fe alloy include Kovar. Among them, in the present embodiment, it is preferable that the optical window 221 be formed of sapphire, and therefore, it is preferable to use Kovar, which has a thermal expansion coefficient close to that of sapphire, as the material forming the optical window holding member 222.

  The optical window holding member 222 is preferably formed of the same material as the housing 23 that fixes the optical window holding member 222. Since the optical window holding member 222 and the housing 23 are exposed to the preliminary combustion chamber 26, they are susceptible to the temperature of the preliminary combustion chamber 26. If the optical window holding member 222 and the housing 23 are made of the same material, they have the same thermal expansion coefficient. Therefore, even if the optical window holding member 222 and the housing 23 become high temperature (for example, several hundred degrees C. to about 1000 degrees C.) under the influence of the temperature of the preliminary combustion chamber 26, the stress caused by the difference of the thermal expansion coefficient It can suppress joining to the junction part of the window holding member 222 and the housing 23. FIG. Thereby, due to the stress difference, the joint portion between the optical window holding member 222 and the housing 23 is pulled, and the load applied to the joint portion such as a crack in the joint portion can be reduced. It can be stably fixed to the window holding member 222.

  As shown in FIG. 3, the pre-chamber cap 24A protrudes from the end of the housing 23 to the main combustion chamber 19 side, and is provided such that a predetermined space (pre-chamber) is formed inside. The pre-chamber becomes the preliminary combustion chamber 26. The pre-chamber cap 24A is joined to the housing 23 by brazing material or welding. The pre-chamber cap 24A is formed in a circular shape like the housing 23 when viewed from the axial direction (Z-axis direction) of the igniter 11A.

  As the pre-chamber cap 24A, for example, a heat resistant metal such as iron, a Ni-Fe alloy, a Cr-Fe alloy, a Ni-Cr-Fe alloy, a Ni-Co-Fe alloy, or stainless steel is used. Examples of the Ni—Cr—Fe alloy include inconel. Examples of the Ni—Co—Fe alloy include Kovar.

  As shown in FIGS. 2 and 3, the pre-chamber cap 24A communicates with the main combustion chamber 19 and the pre-combustion chamber 26 on the inner circumferential surface 24b of the pre-chamber cap 24A (pre-chamber holes) 241A-241D. Have In the present embodiment, the pre-chamber holes 241A to 241D provided on the inner circumferential surface 24b which is a plane orthogonal to the axial direction (Z-axis direction) of the pre-chamber cap 24A is referred to as a first pre-chamber hole.

  The first pre-chamber holes 241A to 241D are provided in a circle at substantially equal intervals in the circumferential direction of the inner peripheral surface 24b of the pre-chamber cap 24A. The air-fuel mixture supplied into the main combustion chamber 19 is supplied from the main combustion chamber 19 into the pre-combustion chamber 26 through the first pre-chamber holes 241A to 241D.

  As shown in FIG. 3, the first pre-chamber holes 241A to 241D are preferably provided on the inner peripheral surface 24b of the pre-chamber cap 24A so that the respective axes (center axes of the holes) do not overlap the ignition point BP. This can reduce the flow of the air-fuel mixture to the ignition point BP, so the flow velocity of the air-fuel mixture at and near the ignition point BP (near the ignition point BP) decreases. In FIG. 3, only the axes of the first pre-chamber holes 241B and 241D are shown, but the axes of the other first pre-chamber holes 241A and 241C have the same inclination as the axes of the first pre-chamber holes 241B and 241D. .

  As shown in FIG. 3, the first pre-chamber holes 241A to 241D are provided on the inner peripheral surface 24b of the pre-chamber cap 24A so that the respective axes intersect the first interference member 25A. Since the air-fuel mixture flowing into the preliminary combustion chamber 26 from the first pre-chamber holes 241A to 241D easily collides with the first interference member 25A, the flow direction of the air-fuel mixture can be easily changed, and the air-fuel mixture is on the optical window 221 side. It becomes easy to flow toward. Therefore, the flow velocity of the air-fuel mixture at and around the ignition point BP is reduced.

  As shown in FIG. 3, it is preferable that the first pre-chamber holes 241A to 241D be provided such that the ignition points BP are positioned near the intersections of the axes of the first pre-chamber holes 241A to 241D. Of the first pre-chamber holes 241A to 241D, the axes of the opposing holes are provided so as to intersect with a part of the first interference member 25A. Therefore, when the air-fuel mixture supplied from the main combustion chamber 19 into the pre-combustion chamber 26 through the first pre-chamber holes 241A to 241D flows into the ignition point BP and its surroundings, the first interference member 25A Will be changed.

  As shown in FIG. 2, the first pre-chamber holes 241A to 241D oppose any one of the first pre-chamber holes 241A to 241D via the first interference member 25A (via the first interference member 25A). And the opposite side). In the present embodiment, among the first pre-chamber holes 241A to 241D, the first pre-chamber hole 241A and the first pre-chamber hole 241C are provided to face each other via the first interference member 25A. The first pre-chamber hole 241B and the first pre-chamber hole 241D are provided to face each other via the first interference member 25A. Note that the opposed positions do not require that any one of the first pre-chamber holes 241A to 241D and the other holes are completely opposite positions via the first interference member 25A. , It may be partially off.

  The number of first pre-chamber holes 241A to 241D is an even number, but may be an even number or an odd number. When the number of the first pre-chamber holes is an odd number, any one of the first pre-chamber holes should not have another first pre-chamber hole at a position facing through the first interference member 25A. become.

  As shown in FIG. 3, the first interference member 25 </ b> A extends inward from the front inner surface 24 a to the front inner surface 24 a on the main combustion chamber 19 side (that is, the piston 14 (see FIG. 1) side) of the pre-chamber cap 24 </ b> A. It is provided to protrude. That is, the first interference member 25A is formed such that the thickness in the axial direction (Z-axis direction) is larger than the thickness of the pre-chamber cap 24A. In the present embodiment, the first interference member 25A is formed in a cylindrical shape.

  The first interference member 25A has one or both of a function of reducing the flow rate of the air-fuel mixture and a function of changing the flow direction of the air-fuel mixture. That is, the first interference member 25A can function as a flow velocity reducing member or a flow direction changing member.

  As described above, the first interference member 25A is provided on the front inner surface 24a so as to intersect with the respective axes of the first pre-chamber holes 241A to 241D, as shown in FIG. Thus, the air-fuel mixture flowing into the pre-combustion chamber 26 from the first pre-chamber holes 241A-241D collides with the first interference member 25A, thereby changing the flow direction of the air-fuel mixture. It becomes easy to flow toward the side. Therefore, the flow velocity of the mixture at and around the ignition point BP is reduced.

  The first interference member 25A is designed such that the ignition point BP approaches the end face 25a of the first interference member 25A. An air-fuel mixture boundary layer is formed in the vicinity of the end surface 25a of the first interference member 25A. In the boundary layer, the flow rate of the air-fuel mixture becomes slow. Therefore, by providing the end face 25a at a position close to the ignition point BP, the ignition point BP is included in the boundary layer of the air-fuel mixture, so that the initial flame tends to be stably formed.

  In the present embodiment, the first interference member 25A is arranged such that the distance between the ignition point BP and the end surface 25a of the first interference member 25A is 30% or less with respect to the inner diameter of the pre-chamber cap 24A. It is preferable. The first interference member 25A is arranged such that the distance between the ignition point BP and each of the first prechamber holes 241A to 241D is 50% or less of the inner diameter of the prechamber cap 24A. It is preferable that Thereby, the flow velocity of the air-fuel mixture flowing around the ignition point BP and its surroundings can be reduced, and the flow velocity of the air-fuel mixture flowing outside the ignition point BP and its surroundings can be increased. As the flow velocity of the air-fuel mixture in the preliminary combustion chamber 26 is higher, the flame generated in the preliminary combustion chamber 26 tends to spread more quickly, and the point flame injection becomes stronger.

  As shown in FIG. 2, the first interference member 25 </ b> A is preferably provided so as to intersect the facing pre-chamber holes among the first pre-chamber holes 241 </ b> A to 241 D with a straight line. In this embodiment, a part of the first interference member 25A is a straight line connecting the facing first pre-chamber hole 241A and the first pre-chamber hole 241C, and the facing first pre-chamber hole 241B and the first pre-chamber It is provided so as to intersect with a straight line connecting the hole 241D. Thus, the air-fuel mixture supplied from the main combustion chamber 19 into the preliminary combustion chamber 26 through the first pre-chamber holes 241A to 241D is more likely to hit the first interference member 25A, and the flow direction of the air-fuel mixture is changed. Is done.

  The material forming the first interference member 25A is not particularly limited, but can be manufactured using the same material as the pre-chamber cap 24A.

  In the ignition device 11A configured as described above, the laser light LB emitted from the laser device 21 is condensed in the preliminary combustion chamber 26 through the optical window 221 as shown in FIG. When the air-fuel mixture supplied to the main combustion chamber 19 is forcibly supplied from the main combustion chamber 19 through the first pre-chamber holes 241A to 241D into the preliminary combustion chamber 26, the condensing point of the laser beam LB. Becomes the ignition point BP, and the fuel in the air-fuel mixture burns (preliminary combustion). As the fuel pre-burns, an ignition flare (point flame) 31 is generated as shown in FIG. The generated point flame 31 is injected into the main combustion chamber 19 through the first pre-chamber holes 241A to 241D. The point flame 31 injected into the main combustion chamber 19 ignites and burns the fuel in the mixture of the main combustion chamber 19 (main combustion). In addition, the ignition flame of the main combustion chamber 19 is increased by the point flame 31 spouting from the first pre-chamber holes 241A to 241D to the main combustion chamber 19.

  At this time, as shown in FIG. 3, the air-fuel mixture is supplied from the main combustion chamber 19 into the preliminary combustion chamber 26 through the first pre-chamber holes 241A to 241D. When the air-fuel mixture flows into the preliminary combustion chamber 26, as shown in FIG. 3, the air-fuel mixture flows along the flow F1-1. When the air-fuel mixture collides with the first interference member 25A, the flow direction of the air-fuel mixture changes to become a flow F1-2, and the air-fuel mixture is on the side of the window member 22 including the optical window 221 and the optical window holding member 222. It flows toward. When the air-fuel mixture collides with the window member 22, the flow of the air-fuel mixture is reversed and flows toward the first interference member 25A as in the flow F1-3. The air-fuel mixture flows toward the first interference member 25A at and around the ignition point BP, as in the flow F1-4. The air-fuel mixture in the preliminary combustion chamber 26 is preliminarily burned at the ignition point BP, and then discharged from the first prechamber holes 241A to 241D (see FIG. 2) as an ignition flame 31 (see FIG. 4). In the present embodiment, the ignition point BP and its surroundings are in the boundary layer of the air-fuel mixture on the end surface 25a of the first interference member 25A, so that the flow rate of the air-fuel mixture is reduced, which is advantageous for the formation of a stable initial flame. become.

  By changing the flow of the mixture from the flow F1-1 to the flow F1-2, the ignition point BP is not exposed to the flow of the mixture from the first pre-chamber holes 241A to 241D. Therefore, the flame can be stably formed at the initial stage of the fuel combustion.

  As described above, in the ignition device 11A, the first interference member 25A is inserted into the preliminary combustion chamber 26 inside the pre-chamber cap 24A, from the front inner surface 24a on the main combustion chamber 19 side of the pre-chamber cap 24A. It is provided so as to protrude. The first interference member 25A is provided on the front inner surface 24a so as to intersect the axes of the first pre-chamber holes 241A to 241D. The first pre-chamber holes 241A-241D are provided such that the ignition point BP is present near the axis of the first pre-chamber holes 241A-241D. By providing the first interference member 25A so as to intersect the axis of the first prechamber holes 241A to 241D, the first interference member 25A flows into the preliminary combustion chamber 26 from the first prechamber holes 241A to 241D. Change the direction of the mixture flow. As a result, it is possible to slow the flow rate of the mixture at the ignition point BP and its surroundings. Thus, the initial flame can be stably formed at the ignition point BP, so that the fuel can be stably ignited at the time of ignition of the fuel. As a result, the stability of fuel ignition by the laser beam LB in the preliminary combustion chamber 26 can be enhanced. Further, since the flow rate of the air-fuel mixture other than the ignition point BP and its surroundings can be maintained, the ignition flame 31 (see FIG. 4) can be uniformly injected into the main combustion chamber 19 from the first prechamber holes 241A to 241D.

  The ignition device 11A is provided with the first interference member 25A such that the ignition point is present in the boundary layer formed in the vicinity of the end face 25a of the first interference member 25A. Since the flow velocity of the air-fuel mixture in the boundary layer can be made slower than the flow velocity outside the boundary layer, the flow velocity of the air-fuel mixture flowing around the ignition point BP and its surroundings can be lowered. This makes it possible to slow the flow rate of the air-fuel mixture at and around the ignition point BP.

  The ignition device 11A is provided with the first interference member 25A so as to intersect the axis of the first pre-chamber holes 241A to 241D. As a result, the air-fuel mixture supplied from the first pre-chamber holes 241A to 241D easily hits the first interference member 25A, so that the flow rate of the air-fuel mixture around the ignition point BP and its surroundings can be reduced. As a result, the fuel can be ignited stably when the fuel is ignited. Further, since the flow rate of the air-fuel mixture other than the ignition point BP and its surroundings can be maintained, the ignition flame 31 (see FIG. 4) can be easily injected uniformly into the main combustion chamber 19 from the first prechamber holes 241A to 241D. Become.

  The igniter 11A includes a first interference member 25A, a straight line connecting the first pre-chamber hole 241A and the first pre-chamber hole 241C facing each other via the first interference member 25A, and the first interference member 25A. The first pre-chamber hole 241B and the first pre-chamber hole 241D are provided so as to intersect with a straight line connecting them. Thus, the air-fuel mixture supplied from the first pre-chamber holes 241A to 241D can easily hit the first interference member 25A. As a result, since the flow velocity of the mixture at the ignition point BP and its surroundings can be reduced, the fuel can be ignited stably when the fuel is ignited. In addition, since the flow rate of the air-fuel mixture other than the ignition point BP and its surroundings can be maintained, it is easy to inject the ignition flame 31 (see FIG. 4) from the first prechamber holes 241A to 241D uniformly into the main combustion chamber 19. Become. In addition, the number of first interference members 25A can be minimized.

  In the ignition device 11A, the first pre-chamber holes 241A to 241D are arranged outside the half (1/2 × R) of the radius R of the inner peripheral surface 24b of the pre-chamber cap 24A as shown in FIG. Yes. Thereby, in order to prevent the initial flame from being cooled by the window member 22 and the inner peripheral surface 24b by forming the flow of the air-fuel mixture toward the first interference member 25A side around the ignition point BP, An initial flame can be formed stably. Thus, the ignition device 11A can reduce the cooling of the initial flame, and thus can improve the stability of the ignition.

  In the case of a conventional ignition device using a pre-chamber plug, in the pre-chamber, mixing is performed from the main combustion chamber toward the inside of the pre-chamber through a pre-chamber hole communicating the inside of the pre-chamber and the main combustion chamber of the engine in the compression stroke of the engine. Qi flows in. Since the air-fuel mixture that has flowed in proceeds toward the back of the pre-chamber (on the side of the laser device and the spark plug shown in FIG. 1), this flow causes the initial flame to flow to the back of the pre-chamber. Since the wall surface on the back side of the pre-chamber is generally cooled by the cooling water of the cylinder head, the temperature is low. On the other hand, the wall surface of the pre-chamber head protruding into the main combustion chamber is not in contact with the cylinder head, so the temperature is high. Therefore, if the initial flame is flown into the back of the pre-chamber and contacts the wall surface on the back side of the pre-chamber or the wall surface of the laser device or the spark ignition plug, the initial flame generated in the pre-chamber may be cooled. is there. In particular, when a spark ignition plug is used, when the initial flame generated between the center electrode and the ground electrode is cooled, the initial combustion rate decreases and the misfire rate increases or the initial combustion rate varies, resulting in a combustion cycle. If the fluctuation of the increase, the ignition becomes unstable. In particular, ignition tends to be unstable when the combustion conditions are low. As such a combustion condition with a slow combustion speed, for example, in the case of a gas engine, there is a case of lean combustion (lean burn) or the like. In the case of an engine other than a gas engine, a fuel type having a low combustion speed may be used.

  On the other hand, as described above, the ignition device 11A has the first pre-chamber holes 241A to 241D formed of half the radius R of the inner peripheral surface 24b of the pre-chamber cap 24A (1 / It is arranged outside 2 × R). Thereby, since the flow of the air-fuel mixture toward the first interference member 25A side is formed around the ignition point BP and the periphery thereof, the initial flame is caused to flow on the window member 22 side and the inner surface 24b. Can be prevented. The window member 22 and the inner circumferential surface 24b are generally cooled by the cooling water of the cylinder head 12 (see FIG. 1), so the temperature is low. On the other hand, since the prechamber cap 24A is not in contact with the cylinder head 12 (see FIG. 1), the temperature is high. The ignition device 11A can prevent the initial flame from flowing toward the window member 22 side and the inner peripheral surface 24b, and thus can prevent the initial flame from being cooled by the window member 22 side and the inner peripheral surface 24b. Therefore, since the ignition device 11A can hold the initial flame generated in the pre-chamber cap 24A to form a stable initial flame, the ignition stability can be enhanced. When the burning rate is high, flame growth can be performed before the initial flame flows to the window member 22. Therefore, for example, in the case of lean burn, or in the combustion conditions where the initial flame is difficult to grow, such as when the ignition point BP or the turbulent flow of the air-fuel mixture in the pre-chamber cap 24A or the flow velocity is weak, It can form an initial flame stably.

  The ignition device 11A is provided with the first pre-chamber holes 241A to 241D in a circle at substantially equal intervals in the circumferential direction of the inner circumferential surface 24b of the pre-chamber cap 24A. Since the axes of the first pre-chamber holes 241A to 241D are uniformly arranged with respect to the main combustion chamber 19, flame injection from the pre-chamber cap 24A is performed in a uniform direction with respect to the main combustion chamber 19. Thereby, the flame spread in the main combustion chamber 19 becomes uniform, and the combustion speed of the main combustion chamber 19 can be increased.

  The igniter 11A is inserted into the cylinder head 12 with the pre-chamber cap 24A in contact with the cylinder head 12. Accordingly, the ignition device 11A can be easily attached and detached from the pre-chamber cap 24A.

  Since the engine 10 (see FIG. 1) includes the igniter 11A, it can be ignited stably and can be operated efficiently. Thereby, the performance of the engine 10 (see FIG. 1) can be improved.

  In this embodiment, the case where the ignition device 11A according to this embodiment is used as an internal combustion engine in an ignition device for a power generation gas engine in which a piston is moved by combustion gas has been described. However, the present invention is not limited to this. The igniter 11A can be used, for example, for producing a combustion gas by burning a fuel, such as a rotary engine, a gasoline engine for automobiles, a gas turbine engine, or a jet engine. The igniter 11A can also be used for cogeneration, which is a system for extracting energy, heat or cold using exhaust heat to increase energy efficiency as a whole.

  In the present embodiment, the first interference member 25A is formed in a cylindrical shape, but the shape of the first interference member 25A is an elliptic cylinder, polyhedron, cylinder, elliptic cylinder, cone, elliptic cone, cone. It may be a table, an elliptic frustum or a sphere. In this case, it is preferable that a portion closest to the ignition point of the first interference member 25A be a surface or a curved surface. If the portion closest to the ignition point of the first interference member 25A is a surface or a curved surface, the effect of changing the flow direction of the air-fuel mixture, the effect of reducing the flow velocity using the boundary layer, and the stagnation point described later It is easy to obtain a flow velocity reduction effect.

  In the present embodiment, the axes of the first pre-chamber holes 241A to 241D intersect with the first interference member 25A, but they do not have to intersect.

  In the present embodiment, the four first pre-chamber holes 241A to 241D are provided on the inner circumferential surface 24b of the pre-chamber cap 24A, but the number of first pre-chamber holes provided on the inner circumferential surface 24b is at least 2 It is sufficient if there are two or more.

  In the present embodiment, the first pre-chamber holes 241A to 241D are all arranged on a concentric circle as shown in FIG. 2, but may not be arranged on the concentric circle.

  In the present embodiment, the first interference member 25A may be welded to the front inner surface 24a of the pre-chamber cap 24A, or the pre-chamber cap 24A and the first interference member 25A are cut by a 3D printer or the like and the front inner surface. It may be formed integrally with 24a.

  In the present embodiment, the pre-chamber cap 24A is joined to the housing 23, but may be joined to the window member 22 or the cylinder head 12, for example.

  In the present embodiment, the first interference member 25A is provided on the front inner surface 24a of the pre-chamber cap 24A. However, the first interference member 25A only needs to be able to reduce the flow rate of the air-fuel mixture. You may provide in the housing 23. FIG.

  In the present embodiment, the housing 23 and the pre-chamber cap 24A may be formed of the same material as the optical window holding member 222, in addition to the case where the housing 23 is formed of the same material as the optical window holding member 222.

Second Embodiment
An ignition device according to a second embodiment will be described with reference to the drawings. The members having the same functions as those of the above-described embodiment are denoted by the same reference numerals, and the detailed description thereof is omitted. The igniter according to the present embodiment is the same as the igniter 11A of the first embodiment shown in FIGS. 2 and 3 except that a prechamber hole is further provided on the front inner surface 24a of the prechamber cap 24A of the igniter 11A. Therefore, only the configuration of the pre-chamber cap will be described.

  FIG. 5 is a front view showing the configuration of the pre-chamber cap when the ignition device according to the second embodiment is viewed from the main combustion chamber side, and FIG. 6 is a cross-sectional view taken along 2A-2A shown in FIG. 7 is a cross-sectional view taken along the line 2B-2B shown in FIG. As shown in FIGS. 5-7, the igniter 11B has second pre-chamber holes 242A-242D in the front inner surface 24a of the pre-chamber cap 24B. In the present embodiment, the pre-chamber holes 242A to 242D are referred to as second pre-chamber holes in the front inner surface 24a in the axial direction (Z-axis direction) of the pre-chamber cap 24B.

  As shown in FIG. 5, the second pre-chamber holes 242 </ b> A to 242 </ b> D are positioned at four corners of the square shape on the front inner surface 24 a when the end portion of the pre-chamber cap 24 </ b> B is viewed toward the laser light incident side. Are arranged as follows.

  As shown in FIG. 7, the axes of the second pre-chamber holes 242A to 242D are provided substantially parallel to the central axis J in the longitudinal direction of the igniter 11B. The second pre-chamber holes 242A to 242D are provided such that their axes are not near the ignition point BP. In FIG. 7, only the axes of the second prechamber holes 242B and 242D are shown, but the axes of the other second prechamber holes 242A and 242C also show the same inclination as the axes of the second prechamber holes 242B and 242D. .

  The second pre-chamber holes 242A to 242D are provided such that the distance between the ignition point BP and the axis of each of the second pre-chamber holes 242A to 242D is 10% or more with respect to the inner diameter of the pre-chamber cap 24B. It is preferable. If the distance between the ignition point BP and the axis of each of the second prechamber holes 242A to 242D is 10% or more with respect to the inner diameter of the prechamber cap 24B, the flow velocity of the air-fuel mixture flowing around the ignition point BP Can be reduced more effectively. In addition, if the distance between the ignition point BP and the axis of each of the second prechamber holes 242A to 242D is 10% or more with respect to the inner diameter of the prechamber cap 24B, the ignition point BP and a region other than the surrounding area are set. The flow velocity of the flowing mixture can be increased.

  As shown in FIG. 5, the second pre-chamber holes 242A to 242D are disposed outside a half (1/2 × R) of the radius R of the inner circumferential surface 24b of the pre-chamber.

  As shown in FIGS. 6 and 7, the first interference member 25 </ b> A is provided on the front inner surface 24 a so that its axial direction is parallel to the center line of the ignition device 11 </ b> B. The pre-chamber holes 242A to 242D are provided so as not to overlap with the axis. Therefore, the air-fuel mixture that has flowed into the preliminary combustion chamber 26 from the second pre-chamber holes 242A to 242D flows as a flow F2-1 and does not collide with the first interference member 25A. Therefore, the flow of the air-fuel mixture passing through the second pre-chamber holes 242A to 242D is hardly changed.

  In the igniter 11B, when the air-fuel mixture in the preliminary combustion chamber 26 pre-burns at the ignition point BP, the point flames 31 (see FIG. 4) from the first pre-chamber holes 241A to 241D in the bore direction (X-axis direction) of the cylinder 13. Spray. From the second pre-chamber holes 242A to 242D, a point flame 31 (see FIG. 4) is injected mainly in the piston axial direction (+ Z axis direction) of the main combustion chamber 19 of the engine 10 (see FIG. 1). A point flame 31 (see FIG. 4) injected into the main combustion chamber 19 ignites and burns fuel in the mixture of the main combustion chamber 19 (main combustion). In addition to the first pre-chamber holes 241A to 241D, the ignition flame 31 (see FIG. 4) is further ejected from the second pre-chamber holes 242A to 242D to the main combustion chamber 19, thereby igniting the ignition energy of the main combustion chamber 19. Is further increased.

  At this time, air-fuel mixture is supplied from the main combustion chamber 19 into the preliminary combustion chamber 26 through the first pre-chamber holes 241A to 241D. The flows F1-1 to F1-4 of the air-fuel mixture in the pre-chamber cap 24B are the same as in the first embodiment described above, and thus the description thereof is omitted.

  As shown in FIG. 7, the air-fuel mixture is supplied from the main combustion chamber 19 into the pre-combustion chamber 26 through the second pre-chamber holes 242A to 242D. When the air-fuel mixture flows into the preliminary combustion chamber 26, the air-fuel mixture flows toward the window member 22 along the inner peripheral surface 24b as in the flow F2-1. The reason why the air-fuel mixture flows along the inner peripheral surface 24b is due to the Coanda effect that draws the flow of the air-fuel mixture to the wall due to the viscosity characteristics of the air-fuel mixture.

  When the air-fuel mixture collides with the window member 22, the flow of the air-fuel mixture is reversed and flows toward the first interference member 25A as in the flow F2-2. The air-fuel mixture flows toward the first interference member 25A at and around the ignition point BP, as in the flow F2-3. The air-fuel mixture in the preliminary combustion chamber 26 is pre-combusted at the ignition point BP, and then discharged from the second prechamber holes 242A to 242D (see FIG. 5) as an ignition flame 31 (see FIG. 4). In the present embodiment, the ignition point BP and its surroundings are in the boundary layer of the air-fuel mixture on the end surface 25a of the first interference member 25A, so that the flow rate of the air-fuel mixture is reduced, which is advantageous for the formation of a stable initial flame. become.

  The air-fuel mixture supplied into the preliminary combustion chamber 26 through the second pre-chamber holes 242A to 242D (see FIG. 5) is directed toward the window member 22 along the inner peripheral surface 24b as in the flow F2-1. Flowing. Therefore, the ignition point BP is not exposed to the flow of the mixture from the second pre-chamber holes 242A to 242D. Therefore, a flame can be stably formed at the initial stage where the fuel burns.

  The ignition device 11B has a plurality of second prechamber holes 242A to 242D on the front inner surface 24a so that the axes of the second prechamber holes 242A to 242D do not intersect the first interference member 25A. Thus, the flow velocity of the mixture flowing through the region other than the vicinity of the ignition point BP in the preliminary combustion chamber 26 can be increased while reducing the flow velocity of the ignition point BP and the mixture around the ignition point BP. When the flame stably ignited at the ignition point BP and its surroundings reaches a region other than the region around the ignition point BP, the region other than the region around the ignition point BP has a high flow velocity of the air-fuel mixture. The flame spreads faster. Since the flame spreads more quickly in the preliminary combustion chamber 26, the air-fuel mixture in the preliminary combustion chamber 26 can be strongly injected into the main combustion chamber 19 from the second pre-chamber holes 242A to 242D. Fuel combustion can be further advanced.

  As with the ignition device 11A according to the first embodiment, the ignition device 11B is provided with the first interference member 25A so as to intersect with the axes of the first prechamber holes 241A to 241D. As a result, the igniter 11B can stably ignite the fuel at the time of ignition of the fuel, and easily makes the point flame 31 (see FIG. 4) uniformly from the first pre-chamber holes 241A to 241D to the main combustion chamber 19. Can be injected.

  Since the ignition device 11B is provided with the second pre-chamber holes 242A to 242D on the front inner surface 24a so as to be positioned at the four corners of the square shape, the air-fuel mixture in the preliminary combustion chamber 26 is supplied to the second pre-chamber holes 242A to 242A. The fuel can be injected from 242D toward the main combustion chamber 19 almost uniformly. Thereby, the combustion of the main combustion chamber 19 can be made more uniform and faster.

  In the ignition device 11B, the number of second pre-chamber holes 242A to 242D is the same as the number of first pre-chamber holes 241A to 241D. The first pre-chamber holes 241A to 241D make the direction of the holes the bore direction (X-axis direction) of the cylinder 13. In the second pre-chamber holes 242A to 242D, the direction of the holes is the direction of reciprocation of the piston 14 (Z-axis direction). The main combustion chamber 19 near the top dead center where the combustion is performed is disk-shaped, and the bore direction (X-axis direction) is wide. The number of the second pre-chamber holes 242A to 242D is less than or equal to the number of the first pre-chamber holes 241A to 241D, and the number of pre-chamber holes in the bore direction (X-axis direction) is the reciprocating direction of the piston 14 (Z-axis direction). The number of pre-chamber holes in the As a result, the ignition flame 31 (see FIG. 4) is more easily injected into the main combustion chamber 19 from the second pre-chamber holes 242A to 242D more uniformly. As a result, the flame can be spread uniformly in the main combustion chamber 19, and the combustion speed of the main combustion chamber 19 can be increased.

  The igniter 11B is provided on the prechamber cap 24B so that the axes of the first prechamber holes 241A to 241D and the axes of the second prechamber holes 242A to 242D do not intersect. Thereby, the ignition flame 31 (see FIG. 4) can be spread uniformly in the main combustion chamber 19, so that the combustion speed of the main combustion chamber 19 can be increased.

  In the ignition device 11B, the second pre-chamber holes 242A to 242D are arranged outside the half (1/2 × R) of the radius R of the inner peripheral surface 24b of the pre-chamber cap 24B as shown in FIG. Yes. Thereby, the flow of the air-fuel mixture toward the first interference member 25A side is formed around the ignition point BP and its periphery, so that the initial flame can be prevented from flowing to the window member 22 and the inner peripheral surface 24b. It is possible to prevent the flame from being cooled by the window member 22 or the inner peripheral surface 24b. By holding the initial flame, it is possible to form a stable initial flame, and hence the stability of the ignition can be enhanced. The igniter 11B has a slow burning speed, particularly in the case of lean burn, or when the turbulent flow of the mixture in the ignition point BP or the pre-chamber cap 24B or the flow velocity is low, and the initial flame grows. Even under difficult combustion conditions, an initial flame can be formed stably.

  The ignition device 11B connects the first pre-chamber holes 241A to 241D and the second pre-chamber holes 242A to 242D and the central axis when the ignition device 11B is projected onto a plane perpendicular to the central axis J of the ignition device 11B. The minutes intersect only at the central axis, and all line segments are arranged so as not to overlap. That is, on the projection surface, the first pre-chamber holes 241A to 241D and the second pre-chamber holes 242A to 242D are arranged in a zigzag in the circumferential direction. The axes of the first pre-chamber holes 241A-241D and the second pre-chamber holes 242A-242D are arranged to be uniform with respect to the main combustion chamber 19. Thereby, since the flame can be spread uniformly in the main combustion chamber 19, the combustion speed of the main combustion chamber 19 can be further increased.

  In the present embodiment, the number of the second pre-chamber holes 242A to 242D is four similarly to the first pre-chamber holes 241A to 241D. However, the number of the second pre-chamber holes 242A to 242D is not limited to four. . In the present embodiment, the number of second pre-chamber holes 242A to 242D is preferably equal to or less than the number of first pre-chamber holes 241A to 241D. In general, the shape of the main combustion chamber 19 at the top dead center of the engine 10 (see FIG. 1) is a flat disk, and the length of the cylinder 13 in the bore direction (X-axis direction) is the reciprocating motion of the piston 14 of the cylinder 13. Longer than the length in the direction (Z-axis direction). Therefore, the number of second prechamber holes 242A to 242D for injecting fuel in the preliminary combustion chamber 26 in the bore direction (X-axis direction) is injected in the piston axial direction (Z-axis direction). If the number of the second pre-chamber holes 242A to 242D is equal to or larger than the number of the second pre-chamber holes 242A to 242D, the point flame 31 (see FIG. 4) can be uniformly spread in the main combustion chamber 19.

  In the present embodiment, the second pre-chamber holes 242A to 242D are not arranged inside a half (1/2 × R) of the radius R of the inner circumferential surface 24b of the pre-chamber in the axial direction of the igniter 11A. , Or may be set to intersect half of radius R (1/2 × R).

  In the present embodiment, the angles formed by the axis of the ignition device 11B and the axes of the four second prechamber holes 242A to 242D are all the same, but may be different.

  In the present embodiment, the second pre-chamber holes 242A to 242D are all arranged on a concentric circle as shown in FIG. 2, but may not be arranged on the concentric circle.

Third Embodiment
An ignition device according to a third embodiment will be described with reference to the drawings. The members having the same functions as those of the above-described embodiment are denoted by the same reference numerals, and the detailed description thereof is omitted. The igniter according to the present embodiment changes the size of the first interference member 25A of the igniter 11B of the second embodiment shown in FIGS. 5 to 7 and the direction of the second pre-chamber holes 242A to 242D. It is the same except that it did. Therefore, only the configuration of the pre-chamber cap 24C will be described.

  8 is a front view showing the configuration of the pre-chamber cap when the ignition device according to the third embodiment is viewed from the main combustion chamber side, and FIG. 9 is a cross-sectional view taken along the line 3A-3A shown in FIG. 10 is a cross-sectional view taken along line 3B-3B shown in FIG. As shown in FIGS. 8 to 10, the ignition device 11 </ b> C replaces the first interference member 25 </ b> A of the ignition device 11 </ b> B of the second embodiment shown in FIGS. 5 to 7 with a first interference member 25 </ b> B. It is possessed. The second prechamber holes 242A to 242D of the prechamber cap 24C are provided in the front inner surface 24a so that the axis of the first prechamber holes 241A to 241D and the axis of the second prechamber holes 242A to 242D do not intersect. It is done.

  The diameter of the first interference member 25B when viewed from the direction orthogonal to the axial direction of the first interference member 25B is the same as that of the ignition device 11B of the second embodiment shown in FIGS. It is formed larger than the diameter of one interference member 25A. The diameter of the first interference member 25B is preferably 25% or more with respect to the radius R of the pre-chamber cap 24C, and more preferably in the range of 40% to 80%.

  As shown in FIG. 9, the first pre-chamber holes 241A to 241D are provided on the inner peripheral surface 24b of the pre-chamber cap 24C so that the axis thereof intersects with the first interference member 25B. In FIG. 9, only the axes of the first pre-chamber holes 241B and 241D are shown, but the axes of the other first pre-chamber holes 241A and 241C also show the same inclination as the axes of the first pre-chamber holes 241B and 241D. .

  As shown in FIG. 10, the second pre-chamber holes 242A to 242D are provided on the front inner surface 24a of the pre-chamber cap 24C such that the axis thereof intersects the central axis J in the longitudinal direction of the igniter 11C. In FIG. 10, only the axes of the second prechamber holes 242B and 242D are shown, but the axes of the other second prechamber holes 242A and 242C also show the same inclination as the axes of the second prechamber holes 242B and 242D. .

  An angle α1 (see FIG. 9) formed by the axes of the second pre-chamber holes 242A-242D with respect to the central axis J of the igniter 11B is the first pre-chamber holes 241A-241D with respect to the central axis J of the igniter 11B. It is designed to be larger than the angle β1 (see FIG. 10) formed by the axes. The angle α1 is an example of the angle α formed by the axes of the second prechamber holes 242A to 242D with respect to the central axis J of the ignition device 11B, and the angle β1 is the first angle with respect to the central axis J of the ignition device 11B. It is an example of angle beta which the axis line of 1 pre-chamber hole 241A-241D makes.

  In the present embodiment, the first pre-chamber holes 241A to 241D have an angle α1 formed by the central axis J in the longitudinal direction (Z-axis direction) of the laser device 21 and the axis of the first pre-chamber holes 241A to 241D of 45 ° or more. It is provided to become. Further, the second pre-chamber holes 242A to 242D are provided such that an angle β1 formed by the central axis J of the laser device 21 and the axis of the second pre-chamber holes 242A to 242D is less than 45 °. If the angle α1 and the angle β1 are within the above ranges, the ignition flame 31 is uniformly injected into the main combustion chamber 19, so that the flame can be spread uniformly in the main combustion chamber 19. The angle α1 is preferably 50 ° or more, more preferably 55 ° or more. 40 degrees or less are preferable and, as for angle (beta) 1, 35 degrees or less are more preferable.

  The second pre-chamber holes 242A to 242D are similar to the first pre-chamber holes 241A to 241D of the ignition device 11A described above, and the air-fuel mixture flowing in from the second pre-chamber holes 242A to 242D is first in the ignition point BP and its surroundings. It is preferable to arrange so as to face the interference member 25B. As shown in FIG. 8, the second pre-chamber holes 242A to 242D are disposed outside a half (1/2 × R) of the radius R of the inner circumferential surface 24b of the pre-chamber.

  In the igniter 11C, the point flame 31 (see FIG. 4) injected into the main combustion chamber 19 from the first pre-chamber holes 241A-241D and the second pre-chamber holes 242A-242D is the fuel in the mixture of the main combustion chamber 19. Is ignited and burned (main combustion). The air-fuel mixture is supplied from the main combustion chamber 19 into the preliminary combustion chamber 26 through the first pre-chamber holes 241A to 241D and the second pre-chamber holes 242A to 242D.

  At this time, the air-fuel mixture is supplied from the main combustion chamber 19 into the preliminary combustion chamber 26 through the first pre-chamber holes 241A to 241D (see FIG. 8). As shown in FIG. 9, the air-fuel mixture that has passed through the first pre-chamber holes 241A to 241D flows in the preliminary combustion chamber 26 toward the first interference member 25B as in a flow F3-1. When the air-fuel mixture collides with the first interference member 25A, the flow direction of the air-fuel mixture changes, and the air-fuel mixture flows toward the window member 22 and collides with the window member 22 as in the flow F3-2.

  When the air-fuel mixture collides with the window member 22, the flow of the air-fuel mixture is reversed and flows from the window member 22 toward the end face 25a of the first interference member 25B as in the flow F3-3. The air-fuel mixture flows toward the first interference member 25B as in the flow F3-3 at and around the ignition point BP. The air-fuel mixture collides with the first interference member 25B to generate a stagnation point of the air-fuel mixture near the collision point between the air-fuel mixture and the first interference member 25B. The stagnation point is a point at which the flow velocity of the air-fuel mixture collides with the first interference member 25B and becomes near zero. In the present embodiment, a stagnation point is formed near the front of the end surface 25a of the first interference member 25B.

  Also, as shown in FIG. 10, the air-fuel mixture supplied into the precombustion chamber 26 through the second prechamber holes 242A to 242D (see FIG. 8) flows into the precombustion chamber 26 as shown by a flow F4-1. The inside flows toward the side surface of the first interference member 25B. When the air-fuel mixture collides with the first interference member 25B, the direction of the air-fuel mixture changes, and the air-fuel mixture flows toward the window member 22 and collides with the window member 22 as in the flow F4-2. .

  When the air-fuel mixture collides with the window member 22, as in the flow F4-3, the flow of the air-fuel mixture is reversed and flows toward the first interference member 25B. The air-fuel mixture flows toward the first interference member 25B in the vicinity of the ignition point BP and like the flow F4-4.

  As described above, the ignition device 11C is provided with the first interference member 25B on the inner peripheral surface 24b of the pre-chamber cap 24C so as to intersect with the axes of the first pre-chamber holes 241A to 241D. The ignition point BP is formed near the stagnation point formed when the air-fuel mixture supplied into the preliminary combustion chamber 26 collides with the end face 25a of the first interference member 25B. Is provided to exist. In the vicinity of the stagnation point, the flow rate of the air-fuel mixture decreases, so that the flow rate of the air-fuel mixture around the ignition point BP can be decreased. Thereby, an initial flame can be stably formed at the ignition point BP.

  Further, as described above, the first interference member 25B is provided on the inner peripheral surface 24b of the pre-chamber cap 24C so as to cross the axis of the first pre-chamber holes 241A to 241D. Thereby, it is possible to reduce that the diffusion of the point flame 31 (see FIG. 4) generated at the ignition point BP is prevented by the first interference member 25B. Therefore, the ignition flame 31 (see FIG. 4) generated by the preliminary combustion in the preliminary combustion chamber 26 can be injected from the first pre-chamber holes 241A to 241D with a more uniform strength.

  The ignition device 11C is provided with second prechamber holes 242A to 242D on the front inner surface 24a of the prechamber cap 24C so that the axis thereof intersects the central axis J of the ignition device 11C. As a result, the axis of the second pre-chamber holes 242A to 242D is substantially the same as the advancing path of the flame from the ignition point BP toward the second pre-chamber holes 242A to 242D. Therefore, the point flame 31 (see FIG. 4) generated at the ignition point BP can be injected from the second pre-chamber holes 242A to 242D with more uniform strength.

  Therefore, since the igniter 11C can make the strengths of the point flames 31 (see FIG. 4) injected from the first pre-chamber holes 241A to 241D and the second pre-chamber holes 242A to 242D more uniform, the main combustion chamber 19 The combustion of the fuel in the air-fuel mixture can be accelerated.

  The ignition device 11C is provided such that an angle β1 formed by the central axis J of the ignition device 11C and the axis line of the second prechamber holes 242A to 242D is less than 45 °. The air-fuel mixture flowing in from the second prechamber holes 242A to 242D can flow toward the window member 22 like the inner peripheral surface 34b of the prechamber due to the Coanda effect. Therefore, a flow toward the main combustion chamber 19 side is surely generated at the ignition point BP, and stable ignition can be achieved.

  Further, the ignition device 11C has the first pre-chamber holes 241A to 241D and the second pre-chamber holes 242A to 242D as shown in FIG. It arrange | positions outside the half (1 / 2xR) of radius R of the surface 24b. Thereby, the flow of the air-fuel mixture toward the first interference member 25B side is formed around the ignition point BP and its periphery, so that the initial flame can be prevented from flowing to the window member 22 and the inner peripheral surface 24b. It is possible to prevent the flame from being cooled by the window member 22 and the inner circumferential surface 24b. By holding the initial flame, it is possible to form a stable initial flame, and hence the stability of the ignition can be enhanced. The igniter 11C is, similarly to the igniters 11A and 11B described above, in particular, for example, as in the case of lean burn or when the turbulence of the mixture in the ignition point BP or the prechamber cap 24C or the flow velocity is weak. Even if the combustion speed is low and the initial flame is difficult to grow, the initial flame can be stably formed.

  The ignition device 11C has second pre-chamber holes 242A to 242D provided in the pre-chamber cap 24C so that the axis thereof intersects the central axis J of the ignition device 11C. Thereby, the air-fuel mixture supplied into the preliminary combustion chamber 26 through the second pre-chamber holes 242A to 242D is directed from the side surface of the first interference member 25B toward the window member 22 as in the flow F4-2. Flowing. Therefore, the ignition point BP is not exposed to the flow of the mixture from the second pre-chamber holes 242A to 242D. Therefore, a flame can be stably formed at the initial stage where the fuel burns.

  In the ignition device 11C, the angle α1 between the axis of the first pre-chamber holes 241A to 241D and the center axis J of the ignition device 11C is the angle α1 and the axis of the second pre-chamber holes 242A to 242D and the center axis J of the ignition device 11C. Is made larger than the angle β. That is, the angle formed between the axis of the first prechamber holes 241A to 241D and the center axis J of the ignition device 11C is an angle α1, and the axis of the second prechamber holes 242A to 242D and the center axis J of the ignition device 11C are formed. When the angle is an angle β, the relationship of angle α1> angle β holds. By making the angle α1 larger than the angle β, the ignition flame 31 (see FIG. 4) can be injected from the first pre-chamber holes 241A to 241D in the bore direction (X-axis direction) in the main combustion chamber 19. Further, the point flame 31 (see FIG. 4) can be easily and uniformly ejected from the first pre-chamber holes 241A to 241D toward the piston 14 side.

  In the present embodiment, the angle of the axis of the second prechamber holes 242A to 242D is such that the air-fuel mixture flowing from the second prechamber holes 242A to 242D can flow along the inner peripheral surface 24b due to the Coanda effect. It may be an angle.

  In the present embodiment, the angles α1 formed by the center line in the longitudinal direction (Z-axis direction) of the laser device 21 and the axis lines of the first prechamber holes 241A to 241D are all the same, but may be different. .

  In the present embodiment, the angles β1 formed by the center line in the longitudinal direction (Z-axis direction) of the laser device 21 and the axis lines of the second prechamber holes 242A to 242D are all the same, but may be different. .

  In the present embodiment, the first pre-chamber holes 241A to 241D and the second pre-chamber holes 242A to 242D intersect the axis of the first pre-chamber holes 241A to 241D and the axis of the second pre-chamber holes 242A to 242D. May be

  In this embodiment, instead of providing the first interference member 25A on the front inner surface 24a of the pre-chamber cap 24C, the shape of the pre-chamber cap 24C may be modified so that the flow rate of the air-fuel mixture can be reduced. .

Fourth Embodiment
An ignition device according to a fourth embodiment will be described with reference to the drawings. The members having the same functions as those of the above-described embodiment are denoted by the same reference numerals, and the detailed description thereof is omitted. The igniter according to the present embodiment changes the configuration of the first interference member 25B of the igniter 11C of the third embodiment shown in FIGS. 8 to 10 and the number of first pre-chamber holes 241A to 241D. Other than that, it is the same. Therefore, in the present embodiment, only the configuration of the pre-chamber cap will be described.

  11 is a front view showing the configuration of the pre-chamber cap when the ignition device according to the fourth embodiment is viewed from the main combustion chamber side, and FIG. 12 is a cross-sectional view taken along the line 4A-4A shown in FIG. FIG. 13 is a cross-sectional view taken along line 4B-4B shown in FIG. As shown in FIGS. 11 to 13, the ignition device 11D is obtained by changing the first interference member 25B of the ignition device 11C of the third embodiment shown in FIGS. 8 to 10 to the first interference member 25D. It is. The igniter 11D is obtained by changing the pre-chamber cap 24A including the second pre-chamber holes 242A to 242D to a pre-chamber cap 24D including the second pre-chamber holes 242A 'and 242B'.

  The second pre-chamber holes 242A ′ and 242B ′ of the pre-chamber cap 24D are arranged so that the axis of the first pre-chamber holes 241A to 241D and the axis of the second pre-chamber holes 242A ′ and 242B ′ do not intersect with each other. Provided in

  The first interference member 25D is formed in a trapezoidal shape when viewed from a direction orthogonal to the axial direction (Z-axis direction), as shown in FIG. The first interference member 25D is designed such that the length of the surface facing the laser device 21 is longer than the length of the surface in contact with the front inner surface 24a of the pre-chamber cap 24C.

  As described above, the first pre-chamber holes 241A to 241D and the second pre-chamber holes 242A 'and 242B' are provided on the front inner surface 24a and the inner circumferential surface 24b of the pre-chamber cap 24D. At this time, as shown in FIGS. 12 and 13, an angle α2 between the central axis J of the igniter 11C and the axis of the first pre-chamber holes 241A to 241D is the central axis J of the igniter 11C and the second pre-chamber. The angle β2 with the axis of the holes 242A ′ and 242B ′ is larger than the angle β2. The angle α2 is an example of an angle α formed by the axes of the second pre-chamber holes 242A to 242D with respect to the central axis J of the ignition device 11B. The angle β2 is the central axis J of the ignition device 11C and the second pre It is an example of the angle (beta) with the axis of chamber hole 242A 'and 242B' to make.

  When the angle α2 is large, the combustion flame can be reduced from being blocked by the first interference member 25D. Therefore, the ignition flame 31 (see FIG. 4) generated in the preliminary combustion chamber 26 is removed from the first prechamber holes 241A to 241D. It is possible to stably inject in the bore direction (X-axis direction) of the main combustion chamber 19. If the angle β2 is small, the ignition flame 31 (see FIG. 4) generated in the preliminary combustion chamber 26 is easily ejected from the second prechamber holes 242A ′ and 242B ′. Therefore, the ignition flame 31 (see FIG. 4) can be stably injected from the second pre-chamber holes 242A ′ and 242B ′ in the reciprocating direction of the piston 14 (see FIG. 1) of the main combustion chamber 19.

  In the present embodiment, the first pre-chamber holes 241A-241D are the angle between the axis of the first pre-chamber holes 241A-241D and the main combustion chamber 19 side of the center line in the longitudinal direction (Z-axis direction) of the laser device 21. It is provided such that α 2 (see FIG. 12) is 45 ° or more. An angle β2 (see FIG. 13) formed by the axis lines of the second prechamber holes 242A ′ and 242B ′ and the main combustion chamber 19 side of the central axis J of the ignition device 11C is provided to be less than 45 °. If the angle α2 and the angle β2 are respectively in the above ranges, a flow toward the junction of the optical window holding member 222 and the prechamber cap 24D occurs, so the flow velocity of the mixture is accelerated in a wide range in the prechamber cap 24D. be able to. Therefore, the flow velocity of the mixture flowing in the region other than the ignition point BP and the surrounding area can be increased. The angle α1 is preferably 50 ° or more, more preferably 55 ° or more. 40 degrees or less are preferable and, as for angle (beta) 1, 35 degrees or less are more preferable.

  In addition, the axes of the second pre-chamber holes 242A 'and 242B' are directed near the optical window holding member 222 in the preliminary combustion chamber 26 and the side surface of the pre-chamber cap 24D. The flow direction of the air-fuel mixture supplied into the preliminary combustion chamber 26 is not necessarily changed by the first interference member 25D immediately after passing through the second pre-chamber holes 242A ′ and 242B ′. Therefore, as in the third embodiment, the preliminary combustion chamber is compared with the case where the flow direction is changed by the first interference member 25B immediately after the air-fuel mixture passes through the second prechamber holes 242A to 242D. The flow rate of the air-fuel mixture circulating in 26 becomes faster. Thereby, the spread of the flame in the preliminary combustion chamber 26 becomes faster.

  In the ignition device 11D, the point flames 31 (see FIG. 4) injected into the main combustion chamber 19 from the first pre-chamber holes 241A to 241D and the second pre-chamber holes 242A 'and 242B' are mixed in the main combustion chamber 19 It burns by igniting the fuel in the air (main combustion). The air-fuel mixture is supplied from the main combustion chamber 19 into the preliminary combustion chamber 26 through the first pre-chamber holes 241A to 241D and the second pre-chamber holes 242A to 242D.

  At this time, air-fuel mixture is supplied from the main combustion chamber 19 into the preliminary combustion chamber 26 through the first pre-chamber holes 241A to 241D. As shown in FIG. 12, the air-fuel mixture that has passed through the first pre-chamber holes 241A to 241D flows in the preliminary combustion chamber 26 toward the first interference member 25D as in a flow F5-1. When the air-fuel mixture collides with the first interference member 25D, the flow direction of the air-fuel mixture changes, and the air-fuel mixture flows toward the window member 22 and collides with the window member 22 as in the flow F5-2.

  When the air-fuel mixture collides with the window member 22, the flow of the air-fuel mixture is reversed, and the air-fuel mixture flows from the window member 22 toward the end face 25a of the first interference member 25B as in the flow F5-3. The air-fuel mixture flows toward the first interference member 25D at and around the ignition point BP, as in the flow F5-4. The air-fuel mixture collides with the first interference member 25D to generate a stagnation point of the air-fuel mixture near the collision point between the air-fuel mixture and the first interference member 25B.

  Further, the air-fuel mixture supplied into the precombustion chamber 26 through the second prechamber holes 242A ′ and 242B ′ flows in the precombustion chamber 26 toward the inner peripheral surface 24b like the flow F6-1. . When the air-fuel mixture collides with the window member 22, the flow of the air-fuel mixture is reversed and flows toward the end face 25a of the first interference member 25D as in the flow F6-2. The air-fuel mixture flows toward the first interference member 25D as in the flow F6-3 at and around the ignition point BP.

  When the air-fuel mixture in the preliminary combustion chamber 26 is pre-combusted at the ignition point BP, the ignition flame 31 (see FIG. 4) is injected from the first pre-chamber holes 241A to 241D in the bore direction (X-axis direction) of the cylinder 13. From the second pre-chamber holes 242A ′ and 242B ′, the ignition flame 31 (see FIG. 4) is injected mainly in the piston axial direction (+ Z-axis direction) of the main combustion chamber 19 of the engine 10 (see FIG. 1).

  As described above, the ignition device 11D includes the first interference member 25D and the second prechamber holes 242A ′ and 242B ′, thereby increasing the flow rate of the air-fuel mixture circulating in the preliminary combustion chamber 26. it can. As a result, the strength of the ignition flame 31 (see FIG. 4) injected from the second pre-chamber holes 242A ′ and 242B ′ can be increased, so that the fuel in the air-fuel mixture in the main combustion chamber 19 is burned. It can be made earlier.

  The ignition device 11D has only two second pre-chamber holes 242A ′ and 242B ′ as the injection holes for the ignition flame 31 (see FIG. 4) provided on the front inner surface 24a. By reducing the number of injection holes of the ignition flame 31 (see FIG. 4) provided in the pre-chamber cap 24D, the ignition flame 31 (see FIG. 4) generated in the precombustion chamber 26 is changed to the second pre-chamber holes 242A ′ and 242B. The fuel can be injected more uniformly into the main combustion chamber 19 '. In addition, the point flame 31 (see FIG. 4) can be more strongly injected into the main combustion chamber 19 from the second pre-chamber holes 242A ′ and 242B ′. Thereby, the combustion effect in the main combustion chamber 19 can be improved more.

  In the present embodiment, the first pre-chamber holes 241A to 241D and the second pre-chamber holes 242A ′ and 242B ′ are the axis lines of the first pre-chamber holes 241A to 241D and the second pre-chamber holes 242A ′ and 242B ′. It may be provided so as to intersect with the axis.

Fifth Embodiment
An ignition device according to a fifth embodiment will be described with reference to the drawings. The members having the same functions as those of the above-described embodiment are denoted by the same reference numerals, and the detailed description thereof is omitted. The igniter according to the present embodiment is the first interference member 25B of the igniter 11C of the third embodiment shown in FIGS. 8 to 10, and the side plate portion formed in a rectangular shape from the front inner surface to the window member It is provided. Therefore, in the present embodiment, only the configuration of the side plate portion will be described.

  14 is a front view showing the configuration of the pre-chamber cap when the ignition device according to the fifth embodiment is viewed from the main combustion chamber side, and FIG. 15 is a sectional view taken along the line 5A-5A shown in FIG. FIG. 16 is a 5B-5B sectional view shown in FIG. 14, and FIG. 17 is a 5C-5C sectional view shown in FIG. As shown in FIGS. 14 and 15, the ignition device 11E includes a side plate formed in a rectangular shape on the outer periphery of the first interference member 25B of the ignition device 11C of the third embodiment shown in FIGS. Parts 251A to 251D are provided.

  The side plate portions 251A to 251D are provided from the front inner surface 24a of the pre-chamber cap 24C to the window member 22. The side plate portions 251A to 251D are provided in the circumferential direction of the first interference member 25B. The side plate portion 251A and the side plate portion 251C are provided on the first interference member 25B so as to face each other via the first interference member 25B. The side plate portion 251B and the side plate portion 251D are provided on the first interference member 25B so as to face each other via the first interference member 25B.

  Although the side plate portions 251A to 251D can be formed using the same material as the first interference member 25B, different materials may be used.

  The side plate portions 251A to 251D can be joined to the first interference member 25B using a known joining method, and may be joined to the first interference member 25B using a brazing material, or may be joined by welding. You may do so.

  In the igniter 11E, the fuel in the mixture of the main combustion chamber 19 is the point flame 31 (see FIG. 4) injected into the main combustion chamber 19 from the first pre-chamber holes 241A-241D and the second pre-chamber holes 242A-242D. Is ignited and burned (main combustion). The air-fuel mixture is supplied from the main combustion chamber 19 into the preliminary combustion chamber 26 through the first pre-chamber holes 241A to 241D and the second pre-chamber holes 242A to 242D.

  At this time, air-fuel mixture is supplied from the main combustion chamber 19 into the preliminary combustion chamber 26 through the first pre-chamber holes 241A to 241D. As shown in FIG. 16, the air-fuel mixture flows F <b> 3-1 to F <b> 3-3 that have passed through the first pre-chamber holes 241 </ b> A to 241 </ b> D are Since this is the same as the case of, the description is omitted.

  As shown in FIG. 17, the air-fuel mixture flows F4-1 to F4-3 that have passed through the second pre-chamber holes 242A to 242D are also igniter 11C according to the third embodiment shown in FIGS. Since this is the same as the case of, the description is omitted.

  The ignition device 11E includes the side plate portions 251A to 251D in the first interference member 25B so that the heat applied to the first interference member 25B can be transmitted to the pre-chamber cap 24C at the time of combustion, so that the first interference member The temperature of 25B can be lowered. Therefore, excessive overheating of the first interference member 25B can be suppressed, so damage to the pre-chamber cap 24C can be suppressed.

[Sixth Embodiment]
An ignition device according to a sixth embodiment will be described with reference to the drawings. The members having the same functions as those of the above-described embodiment are denoted by the same reference numerals, and the detailed description thereof is omitted. The igniter according to the present embodiment changes the number of second pre-chamber holes provided in the front inner surface 24a of the pre-chamber cap 24C of the igniter 11C of the third embodiment shown in FIGS. It is Then, another first interference member is further provided on a part of the outer periphery of the first interference member 25B from the front inner surface 24a to the inner peripheral surface 24b, and a plurality of first interference members are provided. Therefore, in the present embodiment, only the configuration of the other first interference member will be described.

  18 is a front view showing the configuration of the pre-chamber cap when the ignition device according to the sixth embodiment is viewed from the main combustion chamber side, and FIG. 19 is a sectional view taken along the line 6A-6A shown in FIG. FIG. 20 is a cross-sectional view taken along line 6B-6B shown in FIG. As shown in FIGS. 18 to 20, the ignition device 11F includes a pre-chamber cap 24C of the ignition device 11C of the third embodiment shown in FIGS. 8 to 10 and two second pre-chamber holes on the front inner surface 24a. It is changed to the pre-chamber cap 24E provided with 242A and 242B. The igniter 11F is provided with a first interference member 25D from the front inner surface 24a to the inner peripheral surface 24b of the pre-chamber cap 24E.

  The two second pre-chamber holes 242A and 242B are provided on the front inner surface 24a of the pre-chamber cap 24E so as to face each other via the first interference member 25B in the axial direction (Z-axis direction).

  As shown in FIGS. 19 and 20, a pair of first interference members 25D is provided on a part of the outer periphery of the first interference member 25B via the first interference member 25B. As shown in FIG. 19, the pair of first interference members 25D connect the front inner surface 24a, the inner peripheral surface 24b and the first interference member 25B from the front inner surface 24a to the inner peripheral surface 24b of the pre-chamber cap 24E. It is provided to do.

  In the present embodiment, the first interference member 25D is formed in a fan shape when viewed in the axial direction, as shown in FIG. The surfaces of the first interference member 25D that are in contact with the front inner surface 24a and the inner peripheral surface 24b are curved so as to correspond to the front inner surface 24a and the inner peripheral surface 24b.

  The first interference member 25D is, as shown in FIG. 19, axially on the outer periphery of the first interference member 25B when viewed from the direction orthogonal to the axial direction (Z-axis direction) of the first interference member 25B. It is formed to be in contact with the inner circumferential surface 24b and the first interference member 25B. The first interference member 25D is formed such that the diameter of the inner circumferential surface 271 increases from the side surface of the first interference member 25B to the window member 22 side.

  The first interference member 25D can be manufactured using the same material as the first interference member 25B.

  The first interference member 25D can be joined to the first interference member 25B using a known joining method, and may be joined to the first interference member 25B using a brazing material, or may be joined by welding. You may do it.

  In the igniter 11F, a point flame 31 (see FIG. 4) injected into the main combustion chamber 19 from the first pre-chamber holes 241A to 241D and the second pre-chamber holes 242A and 242B is in the mixture of the main combustion chamber 19. The fuel is ignited and burned (main combustion). 21 is a 6C-6C sectional view shown in FIG. 18, and FIG. 22 is a 6D-6D sectional view shown in FIG. As shown in FIG. 21, the air-fuel mixture is supplied from the main combustion chamber 19 into the preliminary combustion chamber 26 through the first pre-chamber holes 241A to 241D, and as shown in FIG. 22, the second pre-chamber holes 242A and 242B. The mixture is supplied into the pre-combustion chamber 26 through the

  At this time, air-fuel mixture is supplied from the main combustion chamber 19 into the preliminary combustion chamber 26 through the first pre-chamber holes 241A to 241D. As shown in FIG. 21, the air-fuel mixture that has passed through the first pre-chamber holes 241A to 241D flows in the preliminary combustion chamber 26 toward the first interference members 25B and 25C as in a flow F5-1. When the air-fuel mixture collides with the first interference members 25B and 25C, the flow direction of the air-fuel mixture changes, and the air-fuel mixture flows toward the window member 22 as in the flow F5-2 and collides with the window member 22. To do. Although FIG. 21 shows only the flow of the mixture flowing from the first pre-chamber holes 241A and 241C, the flow of the mixture flowing from the other first pre-chamber holes 241B and 241D is also the first pre-chamber hole 241A. And a flow similar to that of the mixture flowing from 241C.

  When the air-fuel mixture collides with the window member 22, the flow of the air-fuel mixture is reversed, and the air-fuel mixture flows along the first interference member 25D from the side of the window member 22 like the flow F5-2. It flows toward the end face 25a of the member 25B. The air-fuel mixture flows toward the first interference member 25B as in the flow F5-3 at and around the ignition point BP. When the air-fuel mixture collides with the first interference member 25B, as described above, a stagnation point of the air-fuel mixture is generated in the vicinity of the collision point between the air-fuel mixture and the first interference member 25B.

  In addition, as shown in FIG. 22, the air-fuel mixture supplied into the precombustion chamber 26 through the second prechamber holes 242A and 242B passes through the precombustion chamber 26 in the first precombustion chamber 26 like a flow F6-1. It flows toward the side surface of the interference member 25B. When the air-fuel mixture collides with the first interference member 25B, the flow direction of the air-fuel mixture changes. The air-fuel mixture flows toward the window member 22 substantially in parallel with the inner circumferential surface 24 b as in the flow F 6-2 and collides with the window member 22.

  When the air-fuel mixture collides with the window member 22, the flow of the air-fuel mixture is reversed and flows from the window member 22 side toward the first interference member 25B as in the flow F6-3. The air-fuel mixture flows toward the first interference member 25B as in the flow F6-4 at and around the ignition point BP.

  In the ignition device 11F, as shown in FIG. 21, the first interference member 25B is provided on the inner peripheral surface 24b of the pre-chamber cap 24E so as to intersect the axis of the first pre-chamber holes 241A to 241D. The ignition point BP is formed near the stagnation point formed when the air-fuel mixture supplied into the preliminary combustion chamber 26 collides with the end face 25a of the first interference member 25D. Are provided to be present. In the vicinity of the stagnation point, the flow rate of the air-fuel mixture decreases, so that the flow rate of the air-fuel mixture around the ignition point BP can be decreased. Thereby, an initial flame can be stably formed at the ignition point BP.

  The ignition device 11F includes a first interference member 25D on the first interference member 25B from the front inner surface 24a to the inner peripheral surface 24b of the pre-chamber cap 24E. The first interference member 25D can release the heat of the first interference member 25B to the cylinder head 12 (see FIG. 1) and the window member 22 through the first interference member 25D. The cylinder head 12 (see FIG. 1) and the ignition device 11F are cooled by a cooling liquid (not shown), and the side surfaces of the window member 22 and the prechamber cap 24E are also cooled by the cooling liquid. Therefore, the heat of the first interference member 25B is radiated to the cylinder head 12 (see FIG. 1) and the window member 22 through the first interference member 25D, so that abnormal overheating of the first interference member 25B can be reduced. If the first interference member 25B is abnormally overheated by the combustion heat, the fuel self-ignites near the wall surface, which may cause abnormal combustion such as pre-ignition or knocking. In the ignition device 11F, the heat of the first interference member 25B is radiated to the cylinder head 12 (see FIG. 1) and the window member 22 through the first interference member 25D, thereby causing abnormal overheating of the first interference member 25B. Can be reduced. Therefore, since the ignition device 11F can prevent abnormal combustion from occurring in the main combustion chamber 19, stable operation of the engine 10 (see FIG. 1) can be achieved.

  In the present embodiment, a pair of first interference members 25D is provided on the front inner surface 24a of the pre-chamber cap 24E, but the present invention is not limited to this. The number of first interference members 25D may be one, or three or more, and the size of pre-chamber cap 24E, or the number of first pre-chamber holes 241A to 241D and second pre-chamber holes 242A and 242B. It is possible to design appropriately according to the position and the like.

  In the present embodiment, the axes of the first pre-chamber holes 241A to 241D intersect with the first interference member 25B, but may intersect with the first interference member 25D.

  In the present embodiment, the first interference member 25D may be welded to the front inner surface 24a of the pre-chamber cap 24E, or the pre-chamber cap 24E and the first interference member 25D may be cut by a 3D printer or the like. It may be formed integrally with the inner surface 24a.

[Seventh Embodiment]
An ignition device according to a seventh embodiment will be described with reference to the drawings. The members having the same functions as those of the above-described embodiment are denoted by the same reference numerals, and the detailed description thereof is omitted. The igniter according to the present embodiment includes the other first interference member projecting inward on the inner circumferential surface 24b of the pre-chamber cap 24E of the igniter 11F according to the sixth embodiment shown in FIGS. It is the same except that it is further provided on the ignition point BP side than the first interference member 25B. Therefore, in the present embodiment, only the configuration of the other first interference member will be described.

  FIG. 23 is a front view showing the configuration of the pre-chamber cap when the ignition device according to the seventh embodiment is viewed from the main combustion chamber side, and FIG. 24 is a cross-sectional view taken along the line 7A-7A shown in FIG. FIG. 25 is a 7B-7B sectional view shown in FIG. 24, and FIG. 26 is a 7C-7C sectional view shown in FIG. As shown in FIGS. 23 and 24, the ignition device 11G has a first interference member 25B on the inner peripheral surface 24b of the pre-chamber cap 24E of the ignition device 11F of the sixth embodiment shown in FIGS. And 25D, further includes a first interference member 25E.

  As shown in FIG. 24, the first interference member 25D is formed in a trapezoidal shape when viewed from the direction orthogonal to the axial direction (Z-axis direction). The first interference member 25D is designed such that the length of the surface facing the laser device 21 is longer than the length of the surface in contact with the front inner surface 24a of the pre-chamber cap 24E. Further, as shown in FIG. 25, when the first interference member 25D is viewed from the axial direction (Z-axis direction) of the ignition device 11G, the first interference member 25D is formed in a fan shape.

  As shown in FIG. 23, a pair of first interference members 25E is provided on the inner circumferential surface 24b so as to face the inner circumferential surface 24b of the pre-chamber cap 24E. As shown in FIG. 26, the first interference member 25E is formed in the shape of a convex lens (biconvex lens) having convex surfaces on both surfaces in the axial direction (Z-axis direction). As shown in FIG. 27, the first interference member 25E is formed in a plate shape when viewed from a direction orthogonal to the axial direction (Z-axis direction) of the ignition device 11G.

  As shown in FIG. 24, the first interference member 25E is provided on the ignition point BP side when viewed from a direction orthogonal to the axial direction (Z-axis direction) of the ignition device 11G. In the present embodiment, the first interference member 25E is provided closer to the window member 22 than the ignition point BP with a predetermined distance from the first interference members 25B and 25D.

  As shown in FIG. 26, a gap is formed between the pair of first interference members 25E so that the air-fuel mixture supplied into the preliminary combustion chamber 26 can pass through.

  FIG. 27 is a 7D-7D sectional view shown in FIG. As shown in FIG. 27, the first interference member 25E is provided on the inner circumferential surface 24b of the prechamber cap 24E so as to intersect the axis of the second prechamber holes 242A to 242D.

  The inner diameter, arrangement position, orientation of the holes, the inner shape and volume of the prechamber cap 24E, the shapes of the first interference members 25B to 25D, the first prechamber holes 241A to 241D and the second prechamber holes 242A and 242B The arrangement position and the like are appropriately set in order to generate flows F7-4, F7-5, F8-4 and F8-5 of the mixture described later. Further, the generation of the air-fuel mixture flows F7-4, F7-5, F8-4, and F8-5, which will be described later, can be confirmed from a fluid simulation or the like.

  In the igniter 11G, the first flame 31 (see FIG. 4) injected into the main combustion chamber 19 from the first pre-chamber holes 241A to 241D and the second pre-chamber holes 242A and 242B is in the mixture of the main combustion chamber 19. The fuel is ignited and burned (main combustion). FIG. 28 is a cross-sectional view taken along line 7E-7E shown in FIG. The air-fuel mixture is supplied from the main combustion chamber 19 into the precombustion chamber 26 through the first prechamber holes 241A to 241D and the second prechamber holes 242A and 242B.

  At this time, air-fuel mixture is supplied from the main combustion chamber 19 into the preliminary combustion chamber 26 through the first pre-chamber holes 241A to 241D. As shown in FIG. 28, the air-fuel mixture that has passed through the first pre-chamber holes 241A to 241D flows in the preliminary combustion chamber 26 toward the first interference members 25B and 25C as in a flow F7-1. When the air-fuel mixture collides with the first interference members 25B and 25C, the flow direction of the air-fuel mixture changes direction, and the air-fuel mixture collides with the first interference member 25E as flow F7-2. Although FIG. 28 shows only the flow of the mixture flowing from the first pre-chamber holes 241A and 241C, the flow of the mixture flowing from the other first pre-chamber holes 241B and 241D is also the first pre-chamber hole 241A. And a flow similar to that of the mixture flowing from 241C.

  As in the flow F7-3, the air-fuel mixture flows so as to bypass the first interference member 27D and toward the gap between the pair of first interference members 25E. The air-fuel mixture flows toward the window member 22 side. At this time, a part of the air-fuel mixture flows to the side of the first interference member 25A as in the flow F7-4.

  The air-fuel mixture that has flowed to the first interference member 25A flows from the window member 22 toward the end face 25a of the first interference member 25B as a flow F7-5. The air-fuel mixture flows toward the first interference member 25B at and around the ignition point BP, as in the flow F7-5. The air-fuel mixture collides with the first interference member 25B to generate a stagnation point of the air-fuel mixture near the collision point between the air-fuel mixture and the first interference member 25B.

  On the other hand, when the air-fuel mixture that has flowed through the gap between the pair of first interference members 25E collides with the window member 22, the flow of the air-fuel mixture is reversed, and the air-fuel mixture is the gap between the pair of first interference members 25E. Pass through. The air-fuel mixture that has passed through the gap flows toward the first interference member 25B together with the air-fuel mixture separated without flowing into the gap as in the flow F7-4.

  In addition, as shown in FIG. 27, the air-fuel mixture supplied into the precombustion chamber 26 through the second prechamber holes 242A and 242B passes through the precombustion chamber 26 in the first precombustion chamber 26 like a flow F8-1. It flows toward the side of the interference member 25B and the surface side of the first interference member 25D. When the air-fuel mixture collides with the first interference members 25B and 25C, the flow direction of the air-fuel mixture changes, and the air-fuel mixture flows like the flow F8-2 and collides with the first interference member 25E.

  As in the flow F8-3, the air-fuel mixture flows so as to bypass the first interference member 25E and toward the gap between the pair of first interference members 25E. Then, the air-fuel mixture that has passed through the gap flows toward the window member 22 side. At this time, a part of the air-fuel mixture flows to the first interference member 25A side as a flow F8-4.

  The air-fuel mixture that has flowed to the side of the first interference member 25B flows from the window member 22 toward the end face 25a of the first interference member 25B as a flow F8-5. The air-fuel mixture flows toward the first interference member 25B as in the flow F8-5 at and around the ignition point BP. A flow of air-fuel mixture toward the first interference member 25B is formed around the ignition point BP. The air-fuel mixture collides with the first interference member 25B to generate a stagnation point of the air-fuel mixture near the collision point between the air-fuel mixture and the first interference member 25B.

  On the other hand, when the air-fuel mixture that has flowed through the gap between the pair of first interference members 25E collides with the window member 22, the flow of the air-fuel mixture is reversed, and the air-fuel mixture is the gap between the pair of first interference members 25E. Pass through. The air-fuel mixture that has passed through the gap flows toward the first interference member 25B together with the air-fuel mixture separated without flowing into the gap, as in the flow F8-4.

  The ignition device 11G further includes a pair of first interference members 25E, so that the distance required until the air-fuel mixture flowing from the main combustion chamber 19 reaches the ignition point BP can be shortened. As a result, when the ignition device 11G is used, for example, as a gas engine for power generation as an internal combustion engine, a fresh air-fuel mixture (not much mixed with residual exhaust gas) is easily supplied to the ignition point BP. It can be ignited stably.

  When the ignition device 11G is used as a gas engine for power generation as an internal combustion engine, the pre-chamber cap 24E is filled with exhaust gas (residual exhaust gas) before the compression process. Therefore, in the igniter using the conventional pre-chamber plug, there is a possibility that the mixture gas which has reached the ignition point may contain a large amount of residual exhaust gas components. For example, in lean burn, exhaust gas contains a large amount of nitrogen and unburned residual oxygen. The lean air-fuel mixture in the main combustion chamber is mixed with the exhaust gas in the pre-chamber, so that the air-fuel mixture in the pre-chamber is leaner than the air-fuel mixture in the main combustion chamber. In addition, there is a possibility that ignition can not be performed at least when the mixture at the ignition point is lean. This is because even if the mixture in the main combustion chamber is within the flammability limit concentration, the residual exhaust gas in the pre-chamber is mixed to be supplied to the ignition point BP by mixing the mixture in the main combustion chamber. This is because air may be out of the range of the flammable limit concentration (leaner direction). On the other hand, in the igniter 11G of the present embodiment, the mixture in the main combustion chamber 19 maintains the state within the flammable limit concentration to easily reach the ignition point BP, and the residual exhaust in the prechamber cap 24E. As it becomes less susceptible to the influence of gas, more stable ignition can be achieved. Therefore, the operation of the engine 10 (see FIG. 1) can be further stabilized.

  The ignition device 11G arranges the pair of first interference members 25E such that the axes of the second pre-chamber holes 242A to 242D intersect. Thereby, flows F7-4 and F7-5 can be generated strongly. Thereby, the flow which goes to the main combustion chamber 19 side generate | occur | produces reliably at the ignition point BP, and it can ignite stably.

  In the present embodiment, the axes of the second pre-chamber holes 242A to 242D intersect with the first interference member 25E, but may not intersect with the first interference member 25E.

  In the present embodiment, the shape of the first interference member 25D in the axial direction is a fan shape, but is not limited thereto.

  In the present embodiment, the first interference member 25E is formed in the shape of a biconvex lens as viewed in the axial direction of the ignition device 11G. However, the first interference member 25E can be provided so as to be in contact with the inner peripheral surface 24b. It is not particularly limited as long as a gap can be formed between the interference members 25E.

  In the present embodiment, the first interference member 25E may be welded to the inner peripheral surface 24b of the pre-chamber cap 24E, or the pre-chamber cap 24E and the first interference member 25E are cut by a 3D printer or the like. One interference member 25E may be integrally formed.

[Eighth Embodiment]
An ignition device according to an eighth embodiment will be described with reference to the drawings. The members having the same functions as those of the above-described embodiment are denoted by the same reference numerals, and the detailed description thereof is omitted. The igniter according to the present embodiment changes the number of second pre-chamber holes provided in the front inner surface 24a of the pre-chamber cap 24C of the igniter 11C of the third embodiment shown in FIGS. It is Then, another first interference member is further provided on the first interference member 25B from the front inner surface 24a to the inner circumferential surface 24b, and the second interference member is provided on the inner circumferential surface 24b of the prechamber cap 24C. is there. Therefore, in this embodiment, only the configuration of the other first interference member and the second interference member will be described.

  FIG. 29 is a front view showing the configuration of the pre-chamber cap when the igniter according to the eighth embodiment is viewed from the main combustion chamber side, and FIG. 30 is a sectional view taken along line 8A-8A shown in FIG. 31 is a cross-sectional view taken along the line 8B-8B shown in FIG. 30, and FIG. 32 is a cross-sectional view taken along the line 8C-8C shown in FIG. As shown in FIGS. 29 and 31, the ignition device 11H includes a pre-chamber cap 24C of the ignition device 11C of the third embodiment shown in FIGS. 8 to 10 and two second pre-chamber holes on the front inner surface 24a. It is changed to the pre-chamber cap 24E provided with 242A and 242B. The ignition device 11H includes a first interference member 25F from the front inner surface 24a to the inner peripheral surface 24b of the pre-chamber cap 24E, and further includes a second interference member 27 on the inner peripheral surface 24b.

  As shown in FIGS. 29 and 30, a pair of first interference members 25F is provided so as to face the inner peripheral surface 24b of the pre-chamber cap 24E via the first interference member 25B. The pair of first interference members 25F are provided to connect the front inner surface 24a of the pre-chamber cap 24E, the inner peripheral surface 24b, and the first interference member 25B from the front inner surface 24a to the inner peripheral surface 24b. .

  As shown in FIG. 30, the first interference member 25F extends along the axial direction on the inner peripheral surface 24b of the pre-chamber cap 24E when viewed from a direction orthogonal to the axial direction (Z-axis direction) of the ignition device 11H. It is extended.

  As shown in FIG. 31, the first interference member 25F is fan-shaped in an axial view, and the surfaces in contact with the front inner surface 24a and the inner peripheral surface 24b correspond to the front inner surface 24a and the inner peripheral surface 24b. It is formed so as to be curved.

  The first interference member 25F can be manufactured using the same material as the first interference member 25B.

  The first interference member 25F can be joined to the first interference member 25B using a known joining method, and may be joined to the first interference member 25B using a brazing material, or may be joined by welding. You may do it.

  As shown in FIG. 30, the second interference member 27 is provided on the inner circumferential surface 24b of the pre-chamber cap 24E so as to be in contact with the first interference member 25F.

  The second interference member 27 is formed in a plate shape as shown in FIG. As shown in FIG. 32, the second interference member 27 is a cylindrical body that is formed in a ring shape from the front inner surface 24a to the window member 22 when viewed in the axial direction, and has a through hole 27a.

  FIG. 33 is an 8D-8D sectional view shown in FIG. As shown in FIG. 33, the second interference member 27 is provided on the inner circumferential surface 24b of the pre-chamber cap 24E so as to intersect the axis of the second pre-chamber holes 242A to 242D.

  The second interference member 27 can be manufactured using the same material as the first interference members 25B and 25E.

  The second interference member 27 can be joined to the inner circumferential surface 24b or the first interference member 25F using a known joining method, and may be joined to the inner circumferential surface 24b using a brazing material, or welding And may be joined.

  As shown in FIG. 30, the residual exhaust gas storage space S is formed by the window member 22, the prechamber cap 24D, and the second interference member 27. The air-fuel mixture that has passed through the through hole 27 a of the second interference member 27 is stored as residual exhaust gas in the residual exhaust gas storage space S.

  In the igniter 11H, the first flame 31 (see FIG. 4) injected into the main combustion chamber 19 from the first pre-chamber holes 241A to 241D and the second pre-chamber holes 242A and 242B is in the mixture of the main combustion chamber 19. The fuel is ignited and burned (main combustion). FIG. 34 is a cross-sectional view taken along line 8E-8E shown in FIG. As shown in FIG. 34, the air-fuel mixture is supplied from the main combustion chamber 19 through the first pre-chamber holes 241A to 241D into the pre-combustion chamber 26, and as shown in FIG. The gas is supplied into the preliminary combustion chamber 26 through the prechamber holes 242A and 242B.

  At this time, air-fuel mixture is supplied from the main combustion chamber 19 into the preliminary combustion chamber 26 through the first pre-chamber holes 241A to 241D. As shown in FIG. 34, the air-fuel mixture that has passed through the first pre-chamber holes 241A to 241D flows in the preliminary combustion chamber 26 toward the first interference member 25B as in a flow F9-1. When the air-fuel mixture collides with the first interference members 25B and 25E, the flow direction of the air-fuel mixture changes, and the air-fuel mixture moves toward the through hole 27a of the second interference member 27 as in the flow F9-2. Flowing into. The air-fuel mixture flows into the residual exhaust gas storage space S through the through holes 27a. At this time, a part of the air-fuel mixture flows to the first interference member 25A side as in the flow F9-4. Although FIG. 33 shows only the flow of the air-fuel mixture flowing from the first pre-chamber holes 241A and 241C, the flow of the air-fuel mixture flowing from the other first pre-chamber holes 241B and 241D is also the first pre-chamber hole 241A. And a flow similar to that of the mixture flowing from 241C.

  The air-fuel mixture that has flowed to the side of the first interference member 25A flows from the window member 22 toward the end face 25a of the first interference member 25B as a flow F9-5. The air-fuel mixture flows toward the first interference member 25B as in the flow F9-5 at and around the ignition point BP. When the air-fuel mixture collides with the first interference member 25B, as described above, a stagnation point of the air-fuel mixture is generated in the vicinity of the collision point between the air-fuel mixture and the first interference member 25B.

  On the other hand, the air-fuel mixture that has flowed into the residual exhaust gas storage space S collides with the surface of the window member 22 and diffuses in the direction of the inner peripheral surface 24b as in the flow F9-3. The mixture in the residual exhaust gas storage space S circulates in the residual exhaust gas storage space S.

  As shown in FIG. 33, the air-fuel mixture supplied into the precombustion chamber 26 through the second prechamber holes 242A and 242B passes through the precombustion chamber 26 in the first precombustion chamber 26 like a flow F10-1. It flows toward the side of the interference member 25B and the surface side of the first interference member 25F. When the air-fuel mixture collides with the first interference members 25B and 25E, the flow direction of the air-fuel mixture changes, and the air-fuel mixture collides with the second interference member 27 as in the flow F10-2.

  The air-fuel mixture flows toward the through hole 27a of the second interference member 27 as in the flow F10-3, passes through the through hole 27a, and flows into the residual exhaust gas storage space S. At this time, a part of the air-fuel mixture flows to the side of the first interference member 25B as in the flow F10-5.

  The air-fuel mixture that has flowed toward the first interference member 25B flows from the second interference member 27 toward the end surface 25a of the first interference member 25B as in a flow F10-6. The air-fuel mixture flows toward the first interference member 25B as in the flow F10-6 at and around the ignition point BP. A flow of air-fuel mixture toward the first interference member 25B is formed around the ignition point BP. The air-fuel mixture collides with the first interference member 25B to generate a stagnation point of the air-fuel mixture near the collision point between the air-fuel mixture and the first interference member 25B.

  On the other hand, the air-fuel mixture that has flowed into the residual exhaust gas storage space S collides with the surface of the window member 22 and diffuses in the direction of the inner peripheral surface 24b, as in the flow F10-4. The air-fuel mixture in the residual exhaust gas storage space S circulates in the residual exhaust gas storage space S and passes through the through hole 27 a of the second interference member 27. The air-fuel mixture that has escaped from the through-hole 27a flows toward the first interference member 25B together with the separated air-fuel mixture without flowing into the through-hole 27a as in the flow F10-5.

  Therefore, the ignition device 11H includes the first interference member 25F and the second interference member 27, and the window member 22, the pre-chamber cap 24E, and the second chamber are provided in front of the window member 22 (on the −Z axis direction side). The residual exhaust gas storage space S is formed by the interference member 27 of FIG. Thereby, residual exhaust gas storage space S can function as a gas storage tank which stores air-fuel mixture as residual exhaust gas. Further, since the air-fuel mixture in the residual exhaust gas storage space S moves into the preliminary combustion chamber 26 through the through holes 27a, the air-fuel mixture in the residual exhaust gas storage space S does not easily move into the preliminary combustion chamber 26. . Therefore, the residual exhaust gas in the pre-chamber is stored in the residual exhaust gas storage space S, and the residual ratio of the residual exhaust gas flowing to the ignition point BP is reduced by not mixing it with the air-fuel mixture flowing from the main combustion chamber 19 so much. Can do. The decrease in the residual rate of the residual exhaust gas can enhance the ignition stability at the ignition point BP. Therefore, stable operation of the engine can be achieved by using the ignition device 11G.

  The ignition device 11H flows from the first pre-chamber holes 241A to 241D and the second pre-chamber holes 242A and 242B by forming the residual exhaust gas storage space S on the emission side of the window member 22 in the pre-chamber cap 24E. The mixture can flow into the ignition point BP more quickly. Thereby, the inflow amount of the air-fuel mixture can be increased. As the inflow of the mixture increases, the residual rate of residual exhaust gas in the region near the first pre-chamber holes 241A to 241D and the second pre-chamber holes 242A and 242B decreases. Thereby, the flow volume of the residual exhaust gas supplied to the ignition point BP from the first prechamber holes 241A to 241D and the second prechamber holes 242A and 242B can be reduced.

  In the present embodiment, the axes of the second pre-chamber holes 242A to 242D intersect with the first interference member 25E, but may not intersect with the first interference member 25E.

  In the present embodiment, the shape of the through hole 27a of the second interference member 27 is circular, but it may be a polygon such as a triangle or a rectangle or an ellipse.

[Ninth Embodiment]
An ignition device according to a ninth embodiment will be described with reference to the drawings. The members having the same functions as those of the above-described embodiment are denoted by the same reference numerals, and the detailed description thereof is omitted. In the present embodiment, the ignition device according to the first embodiment spark-ignites the laser device 21 of the ignition device 11A of the first embodiment shown in FIGS. 2 and 3 and the optical window 221 of the window member 22. The configuration is the same except for the change to the plug, so only the configuration of the spark plug will be described.

  35 is a front view showing the configuration of the pre-chamber cap 24A when the ignition device according to the ninth embodiment is viewed from the main combustion chamber side, and FIG. 36 is a sectional view taken along the line 9A-9A shown in FIG. is there. As shown in FIGS. 35 and 36, the ignition device 11 </ b> I uses a spark ignition plug 41 instead of the laser device 21 and the optical window 221 of the window member 22.

  As the spark plug 41, a known spark plug can be used. The spark-ignition plug 41 has an insulator 411, a center electrode 412, and a ground electrode 413.

  The insulator 411 supports the center electrode 412 inside in an electrically insulated state.

  The center electrode 412 is provided so as to protrude from the end of the insulator 411 toward the preliminary combustion chamber 26.

  The ground electrode 413 is formed in a rectangular shape, and is provided at a position separated from the center electrode 412 by a predetermined distance (discharge gap). The ground electrode 413 is fixed to a fixed end provided on the end face of the insulator 411 by welding or the like.

  In the ignition device 11I, the air-fuel mixture supplied to the main combustion chamber 19 of the engine 10 (see FIG. 1) during the intake process of the engine 10 passes through the first prechamber holes 241A to 241D from the main combustion chamber 19. Then, the pre-combustion chamber 26 is forcibly supplied. Thereafter, a voltage is applied between the center electrode 412 and the ground electrode 413 to generate a plasma arc, that is, a spark discharge, in the discharge gap. When a spark discharge is applied to the mixture, a point flame 31 (see FIG. 4) is generated in the discharge gap. The ignition flame 31 (see FIG. 4) is ejected from the first prechamber holes 241A to 241D into the main combustion chamber 19 during the combustion process of the engine 10 (see FIG. 1).

  At this time, the air-fuel mixture that has flowed into the preliminary combustion chamber 26 from the main combustion chamber 19 through the first pre-chamber holes 241A to 241D flows along the flow F11-1. The air-fuel mixture changes its flow direction near the first interference member 25A, becomes a flow F11-2, and flows toward the optical window 221 side. After the air-fuel mixture in the preliminary combustion chamber 26 is burned by the spark discharge generated in the discharge gap, it is discharged from the first pre-chamber holes 241A to 241D as the ignition flame 31 (see FIG. 4). In the present embodiment, in the vicinity of the discharge gap, the flow direction of the air-fuel mixture is changed by the first interference member 25A, so the flow rate of the air-fuel mixture is slow. Therefore, the flow velocity of the mixture is reduced, and the initial flame can be stably formed.

  Generally, in spark ignition using a spark ignition plug, when the flow rate of the air-fuel mixture flowing in the preliminary combustion chamber 26 is high, an initial flame is formed in the preliminary combustion chamber 26 by increasing the discharge energy. According to the present embodiment, since the flow velocity of the air-fuel mixture in the vicinity of the discharge gap can be reduced, the flame kernel can be formed in the initial stage of ignition even if the discharge energy is low. By reducing the discharge energy, wear of the center electrode 412 and the ground electrode 413 can be suppressed.

  Therefore, according to the present embodiment, even when the spark plug 41 is used, the stability of the ignition of the fuel can be enhanced, and the service life of the spark plug 41 can be prolonged.

  As mentioned above, although an embodiment was described, the above-mentioned embodiment is shown as an example and the present invention is not limited by the above-mentioned embodiment. The above-described embodiment can be implemented in various other forms, and various combinations, omissions, replacements, changes, and the like can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and the gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.

10 Internal combustion engine (engine)
11A to 11I Ignition device 19 Main combustion chamber 21 Laser device 22 Window member 221 Optical window 23 Housing 24A to 24E Pre-chamber cap (partition member)
241 Communication hole (pre-chamber hole)
241A to 241D first communication hole (first pre-chamber hole)
242A to 242D, 242A ′, 242B ′ second communication hole (second pre-chamber hole)
25A to 25E first interference member 26 preliminary combustion chamber 27 second interference member 41 spark-ignition plug α1, α2, β1, β2 angle S residual exhaust gas storage space

Special table 2014-522939 gazette

Claims (18)

An ignition device for igniting fuel contained in an air-fuel mixture supplied to a main combustion chamber of an internal combustion engine,
A partition member provided to form a preliminary combustion chamber surrounding an ignition point of the fuel, the partition member including a plurality of communication holes communicating the main combustion chamber and the preliminary combustion chamber;
A first interference member provided so as to protrude inward from the inner surface of the partition member;
, An igniter.   The ignition device according to claim 1, wherein the first interference member is provided to intersect an axis of the at least one communication hole.   The ignition device according to claim 2, wherein the first interference member is provided to intersect a straight line connecting two communication holes. The plurality of communication holes are provided in the first communication hole provided in the partition member such that the axis thereof intersects the first interference member, and in the partition member such that the axis does not intersect the first interference member And a second communication hole provided
The ignition device according to any one of claims 1 to 3.   The ignition device according to claim 4, wherein the second communication hole is provided in the partition member such that an axis of the second communication hole intersects a central axis of the ignition device. Let an angle between the axis of the first communication hole and the central axis of the igniter be an angle α,
When the angle formed by the axis of the second communication hole and the central axis of the ignition device is an angle β,
The ignition device according to claim 4 or 5, wherein the angle α> the angle β.   The ignition device according to any one of claims 4 to 6, wherein the number of the second communication holes is equal to or less than the number of the first communication holes.   The ignition device according to any one of claims 4 to 7, wherein an axis of the first communication hole and an axis of the second communication hole do not intersect.   When the igniter is projected on a plane perpendicular to the central axis of the igniter, assuming that the maximum distance between the central axis and the inner surface of the partition member is R, all the communication holes are R / A from the central axis The ignition device according to any one of claims 1 to 8, which is disposed at a position of 2 or a position outside R / 2 from the central axis.   When the igniter is projected on a plane perpendicular to the central axis of the igniter, the line segments connecting the communication holes with the central axis intersect only at the central axis, and none of the line segments overlap. The igniter as claimed in any one of claims 1 to 9, characterized in that.   The ignition device according to any one of claims 1 to 10 which has a side plate part which connects said 1st interference member and said partition member on the perimeter of said 1st interference member. A plurality of the first interference members are provided on the inner surface of the partition member,
The other first interference member is provided on one or both of a part of the outer periphery of one of the first interference members and the ignition point side of one of the first interference members. -The igniter as described in any one of -11.   The ignition device according to any one of claims 1 to 12, further comprising a second interference member that protrudes from the partition member and has an opening.   The igniter according to claim 13, wherein the second interference member intersects an axis of at least one of the communication holes.   The ignition device according to claim 13, wherein the ignition point is positioned closer to the main combustion chamber than the second interference member.   The ignition device according to any one of claims 1 to 15, wherein the partition member is inserted into the engine head in a state of being in contact with the engine head. Laser light is used to ignite the fuel,
The ignition device according to any one of claims 1 to 16, wherein a condensing point of the laser beam is the ignition point. An internal combustion engine that burns fuel to generate combustion gas,
The main combustion chamber,
And the igniter according to any one of claims 1 to 17.
In the main combustion chamber, the fuel in the main combustion chamber is ignited to perform main combustion, and in the preliminary combustion chamber of the igniter, preliminary combustion is performed prior to the main combustion.
An internal combustion engine in which the fuel in the main combustion chamber is ignited by an ignition flame generated by ignition of the fuel in the preliminary combustion chamber.

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