DE19500501A1 - Method of controlling load changes of IC engine by valves - Google Patents

Abstract

The method is such that in at least one load change channel is opened and closed by a valve moving member operating a valve relative to the valve housing. Part of the valve movement occurs in a closing area of the valve housing. The distance between the valve body and the valve housing remains the same for the relative movement between the valve housing and the closing body. During the other part of the valve movement in the opening area, the flow cross-section of the valve varies unsteadily and the control edge of the valve passes faster. During the opening and closing movements of the valve, the valve body's acceleration and connection is delayed so as to allow passing of the control edge with a higher velocity resulting in adjustable control times.

Description

The invention relates to a method for controlling the La change of combustion engines by valves, wherein in at least one charge exchange channel at least once per Working a valve by moving a valve body so opened and closed relative to a valve housing sen that part of the valve movement in a closing area of the valve housing takes place in which the distance between the valve body and valve housing the for the relative movement between the valve housing and Closing body be the minimum required clearance tolerance is restricted, while the other part of the movement of the Ven til body takes place in an opening area and the Flow cross section of this valve changes suddenly when the valve body is a control edge at high speed happens on the valve body, which the closing area of the opening separation area, and a device for performing of the procedure.

In connection with the increasing pressure to reduce of exhaust emissions and fuel consumption in motor vehicles It is becoming increasingly important to use valve controls on inputs and Outlets of the combustion chambers quickly and precisely current operating condition optimally and new La implementation change process.

Conventional, cam-controlled valves are too slow for this ge, too little variation in their opening and closing times and the change in the flow cross section in the loading rich the control edge is too slow, which is why an exactly defi nated opening start or a precisely defined closing end is missing. For this reason, novel Ven til controls developed, e.g. B. those with electromagnetic cal drive, with closing and opening movements of one up to two milliseconds in prototypes and the start of these valve movements is freely controllable.  

Thus the opening phase lasts approximately from the beginning of the opening movement until the end of the closing movement.

However, these new valve controls show a number of Problems with the realization of fast movements are connected. First of all, high energy consumption that comes from the high accelerations and decelerations and the drive power of conventional controls exceeds. Then there are difficulties with the valves to close quickly enough without the valve body closing hits the valve seat at high speed and this destroyed. The slow process of opening and closing leads to gas dynamic effects, the energetic and thermal efficiency of new charge exchange processes be compromise. Ultimately, the cost of the appara tive effort and for further development to series production very high.

This problem is exacerbated when new procedures dynamic charging should be realized two complete opening and closing processes of an inlet valve tils per suction stroke.

It is therefore an object of the invention to provide inexpensive Ven valve controls for the gas exchange of internal combustion engines to create, where for procedural reasons the Change in valve cross-section at the beginning of valve opening and very quickly at the end of the valve closure, so that exact tax times for the opening and the Opening end can be determined and that these tax times freely selectable in relation to the phase position of the motor. In addition, they should also up to at normal engine speeds 6,000 rpm to be able to complete two complete openings if possible Opening and closing processes of an intake valve per suction stroke perform, while reducing the required drive power and avoiding damaging impacts  speeds between valve body and valve seat or between the moving and still parts of the valve.

This problem is solved with a method of type mentioned in that during the opening movement supply and during the closing movement of this valve the Ven tilkörper accelerated and then decelerated is that passing the control edge at high speed at taxable times.

Because in this way the valve body at the beginning of the valve opening not accelerated from standstill and at the end of the closing process are not delayed until standstill must, the valve body at the beginning of the valve opening and high speed at the end of the closing process, so that the time at which the valve body touches the control edge opening or closing achieved as an exact opening or Closing time can be considered because of the valve cross cut a lot according to the high speed changes quickly without suddenly releasing mass forces become and lead to high mechanical loads.

An advantageous embodiment is that the Ven tilkörper comes to a standstill after its delay, so that about a pause until the beginning of the next valve movement and the time it takes to pass the tax edged the tax times precisely and freely are selectable.

It is particularly advantageous if after another Embodiment of the valve body by a cross to the flow direction of this valve rotating axis.

According to a first variant, the valve body can Move opening and closing in the same direction; particular ders advantageous is a second variant, according to which the public transport tion movement opposite to the closing movement  is. This opens up the possibility that after a be preferred embodiment, the kinetic energy of the valve body pers in a simple manner when delayed by an ener Giespeicher added and to accelerate the valve body pers is used again.

According to an advantageous embodiment of the method, it will used to control a valve that in addition to egg nem valve closing the combustion chamber in its charge Exchange channel is arranged, being a particularly useful Training is that the ge according to the procedure controlled valve as additional valve at high engine speeds open position remains.

A device with a valve housing and a relative to the valve housing by a drive movable valve body per, in which the valve housing one opening and one Has closing area by a control edge of one are separated on which the flow cross section in Valve housing changes suddenly and in the closing area of the Distance between valve body and valve housing remains the same bend to the for the relative movement between the valve housing and closing body the minimum required clearance tolerance is limited, is invented to carry out the method appropriately designed so that the drive is suitable for Valve body an acceleration and deceleration movement phase, freely selectable in such a way to submit that the valve body the control edge with ho speed at a freely selectable time siert.

The valve body can be a linearly movable slide or be an axially displaceable poppet valve or it can to a ver transverse to the flow direction of the valve housing running axis be rotatably mounted in this, then the valve body is preferably a rotatable flap.  

When using such devices in larger tempera areas exposed to fluctuations, e.g. B. when burning motors, the edges of the rotary flaps must be removed from the Ge have a wall that is sufficiently di dimensioned is that the free movement of the flap at the maximum expected temperature remains guaranteed. As a result, the inevitable gap in A residual flow takes place in the closed position of the flap can assume particularly disturbing dimensions if the Device is subjected to higher pressures. It puts therefore in devices in which the opening movement and the closing movement in opposite directions tion run, an advantageous embodiment that the Valve flap in the closed position in an axis of rotation containing, running transversely to the flow axis level and with its edge in all positions such a distance from the Ge in the plane of the flap housing complies with this during operation expected thermal expansion can not be overcome that the circumferential area of each partial surface on the housing one assigned to the stop edge brought up to the axis of rotation is and that these stop edges on different sides the valve flap is arranged and this as the end face seal are assigned.

This construction does not require extensive processing of the Valve flap or the valve housing, rather a ge punched, unprocessed flap and simple pipe material Formation of the housing can be used. Through the all around maintained distance between the edge of the flap and the inner wall the housing can compensate for thermal expansion without the risk of jamming will be. Because the flap all around the stop edges is a good ab seal guaranteed.

A particularly advantageous embodiment consists in that the housing crossed from one of the axis of rotation  Pipe sleeve and two pipes enclosed by this pipe sleeve sections exists, the edges of which face the valve flap on different sides of the axis of rotation as a stop edge for the valve flap in a parallel to the plane of in Closed valve flap level at most up to half the wall thickness of the valve flap pe corresponding distance from the center of rotation to the axis of rotation are introduced and then outside of the swivel range of the valve flap, being an appropriate and simple design is that the valve flap pe facing edges of the pipe sections by a parallel stage in two directions in the direction of flow to the axis of rotation of the valve offset sections are divided, each parallel to the level of the Ven in the closed position valve flap.

If the procedure with an energy storage for recording The kinetic energy is operated according to one th embodiment of the device as the valve body Energy storage assigned a vibration system, being in front preferably the vibration system comprises mechanical springs.

Another advantageous embodiment of the device be is that it includes a facility that is suitable is the energy loss from the movement of this valve to equalize, whereby the device is suitable, the energy preferably compensate for losses with each valve movement.

A particularly advantageous embodiment is that the valve body with springs ver to a spring-mass system tied around the middle position between the two End positions of the valve body is vibratable with a Frequency, the half oscillation period of the desired movement duration between the two end positions corresponds to that before There are directions for supplying energy that the Loss of energy by damping the movement of the lock Compensate body from end position to end position, and that in the  each end position assigned a locking device to the valve body is not.

According to a first variant, the device can be a Include device for electromagnetic energy supply. But it can also be a device for pneumatic or hydraulic energy supply are provided.

A preferred embodiment of the device still exists in that they are in a La is arranged change channel of an internal combustion engine and the natural frequency of the gas oscillation in the line between the opening of this section and that closes the combustion chamber valve of the engine to use gas dynamic change effects in relation to the charge change on a certain one Abge frequency of the charge change of the respective combustion chamber is true.

The freely controllable valve is after a first Va a preferred embodiment of the inlet valve upstream, while according to a second variant the free controllable valve is the inlet valve. But it can also be arranged as an exhaust valve or the exhaust valve downstream.

Another advantageous embodiment is that to seal the closing area at least in selected Positions of the valve body on the valve housing or valve body are provided by labyrinthine depressions, with Rotary flaps also have labyrinth-like recesses on their end faces can have gene.

Based on the exemplary embodiment shown in the drawing le of devices for performing the method is the Invention explained in more detail. It shows:

Fig. 1 shows a schematic representation of a valve with a rotary valve in the open position,

Fig. 2 shows the valve according to Fig. 1 in the closed position,

Fig. 3 shows another embodiment of a valve with rotary door in the closed position,

Fig. 4 shows a variant of the valve shown in Fig. 3 in the closed position,

Fig. 5 shows a cross section through a preferred exporting approximate shape of a rotary flap valve perpendicular to the axis of rotation,

Fig. 6 shows a cross-section through the in Fig. Ven 5 til shown in the direction of the axis of rotation

Fig. 7 is a Rens suitable for carrying out the procedural invention poppet valve motion at the end of Schließbe,

Fig. 8, the. Poppet valve shown in 7 of Be schleunigungsphase in Fig still in the closed state,

9, the poppet valve shown. In the Figs. 7 and 8 at the end of the opening movement,

Fig. 10 is a schematic side view of a valve of the construction shown in Figs. 1 and 2 and present in the obe ren half cut valve housing and in the middle of the valve body movement,

Fig. 11 Fig. 10 similar view with the valve body in the end position at the end of the closing phase,

Opening phase Fig. 12 a in FIGS. 10 and 11 similar view with the valve body in the end position at the end of Publ,

Fig. 13 is a side view of a variant of the in the

Fig valve shown through 12. 10,,

Fig. 14 is a plan view thereof and

Fig. 15 is a schematic representation of the Ladungswechselka channels of a combustion chamber of an internal combustion engine, equipped with valves for applying the inventive method.

The same or corresponding parts are common to all Embodiments marked with the same reference numerals net.  

Figs. 1 and 2 show in the charge changing channel of an internal combustion engine included a total of 10 denote tes valve having a valve housing 12 which includes a flow passage duct 14 with a rectangular cross-section. In the longitudinal median plane of the valve housing 12 , an axis 16 is net angeord, around which a valve body 18 in the form of a rotary flap can be moved. Concentric to the axis 16 , curved wall sections 20 and 22 extend the flow cross section of the valve housing 12 in the region of the axis 16 , so that through the transition from the parallel to the flow direction D side walls 24 and 26 to the curved wall sections 20 and 22 control edges 28 a and 28 b or 30 a and 30 b are formed.

The movement of the valve body 18 is effected by a single drive, for example shown in FIGS. 10 to 14, the practical design of which is free, provided that it is only suitable to execute the movement of the valve body 18 in such a manner with an acceleration and deceleration phase, that the valve body 18 at a freely selectable point in time with respect to the process sequence in the combustion chamber of the engine, the mutually assigned control edges 28 a and 30 a or 28 b and 30 b on the way from the open to the closed valve state and in the opposite direction each with a high Speed happens.

The drive shown in Figs. 10 to 14 consists of a reciprocating between two end positions slider 32 which is fixed to a plate 34 , the movement range of the slider 32 two electromagnets 36 and 38 are assigned. The valve body 18 is connected outside the Ven tilgehäuses 12 with a crank 40 , the free end of which is connected via a link 42 to one end of the slide 32 , the distance between the electromagnets 36 and 38 determining the length of movement of the slide 32 and being so dimensioned that that the valve body 18 is in the plate 34 on the electromagnet 36 in the opening position shown in FIGS . 1 and 12 and when the plate 34 is on the electromagnet 38 in the closed position shown in FIGS . 2 and 11 be found.

The plate 34 is clamped with a shoulder 44 between two in the direction of movement of the slide 32 on both sides of the plate 34 on ordered tension and compression springs 46 and 48 , the ends facing away from the plate 34 on which the solenoids 36 and 38 bear Construction are attached. The springs 46 and 48 endeavor to keep the plate 34 in the central position shown in FIG. 8, so that both springs brake the approach of the plate 34 to one or the other electromagnet by combined tensile and compressive forces, thereby storing the kinetic energy and when the plate 34 is released by one electromagnet to accelerate the moving parts and thus to support the attraction force of the other electromagnet can be used.

The transition from the open to the closed position and vice versa, taking into account the physical constants of the system by timing the excitation of the electromagnets 36 and 38, can be determined very precisely and the requirements of the respective operating state of the combustion engine can be adapted precisely.

The drive described generates a reciprocating movement of the valve body 18 . As a result, only the control edges 28 a and 30 a are used. But it is also a drive suitable that always rotates the valve body 18 in the same direction, so that after passing the control edges 28 a and 30 a and the delay of the valve body 18 in the closing area formed by the curved wall sections 20 and 22 after Acceleration again the control edges 28 b and 30 b are passed and thereby the next opening time is determined.

FIGS. 3 and 4 show a variant of a Drehschieberven TIL's, in which the axis 12 is arranged at the edge of Durchströmquer section of the valve in a pocket 50 parallel to the axis 12 side wall 21, to which a to the axis 12 concentric curved wall section 22 opposite lies. The pocket 50 serves to receive the valve body 18 in the open position.

Between the edge 19 of the valve body 18 facing away from the axis and the wall portion 22 facing it, the closing region bil end, a seal in the form of a look-through labyrinth 52 or 54 is provided in this embodiment, which cuts on the edge 19 or on the wall portion 22 can be trained.

FIGS. 5 and 6 show a variant of the valve shown in Figs. 1 and 2. A generally designated 70 tubular flow line with, for example, a circular cross-section is separated in the region of a housing 72 , which has two coaxial bores 71 and 73 for receiving the separate tube ends 74 and 76 , respectively. A chamber 75 with a rectangular cross section is formed in the housing 72 and is suitable for receiving a rectangular valve flap 78 . This valve flap 78 can be formed as a simple stamped part and is connected to an axis of rotation 80 which is mounted in bearings 82 and 84 on the sleeve 72 and on one side for connection to an actuating or control mechanism from the housing 72 which is led out if necessary, can also be divided in a plane containing the axis of the valve flap.

The section of the axis of rotation 80 led out of the housing 72 is provided with a collar 81 , which forms an abutment for a compression spring 83 surrounding the axis of rotation, which seals a sealing flange 85 within the bearing 84 , which is designed as a releasable cap, on ordered and formed on the axis 80 presses against the inside of the bearing 84 .

The valve flap 78 holds all around such a sufficient distance from the inner wall of the housing 72 that this freedom of movement ensuring distance can also not be overcome by the dimensional changes to be expected during operation under the influence of heat.

In the example shown, the valve flap 78 extends perpendicular to the flow direction or axis of the housing 72 in its closed position and in this closed position the Ven valve flap 78 lies in the closing direction on its axis 80 associated with it on both sides, each approximately U-shaped stop frame 90 and 92 , the legs of which are brought up to the axis of rotation 80 and - in order to enable a position of the valve flap 78 parallel to the direction of flow in the open position - maintain at least one half of the thickness of the valve flap pe 78 corresponding distance from the center of rotation.

With this construction, a valve can be created with simple, cost-effective means, in which in the closed end position of the valve flap 78 there is an end face seal which can withstand high pressures.

FIGS. 7 to 9 show that the inventive method can also be applied to poppet valves. The valve body forming the Ven valve body 18 has a conical valve seat 23 in a valve housing 12 representing the cylinder head of an internal combustion engine associated conical section 25 , to which on the side facing away from the valve stem 27 a cylindrical section 29 joins, which as Closing section is a cylindrical Wan extension section 22 associated with the conical valve seat 23 .

When the valve body 18 moves from the end position shown in FIG. 7, reached at the end of the closing phase, the valve remains closed as long as the cylindrical portion 29 - as shown in FIG. 8 - in the region of the cylindrical wall portion 22 emotional. Only when the section 29 passes the wall section 22 at its end facing away from the valve seat 23 end of the control edge 28 c pas siert to achieve the other valve end position shown in Fig. 9, the valve is opened. During the closing movement, the valve is closed as soon as the cylindrical section 29 passes the control edge 28 c and penetrates into the closing section formed by the wall section 22 , where the movement is delayed until the valve body 18 bears against the valve seat 23 .

Figs. 13 and 14 show a variant of the embodiment shown in FIGS. 10 to 12, by which the mechanical stress is reduced by the specific acting forces. For this purpose, the crank 40 is extended beyond the axis 16 by a crank arm 41 , on which a tension and compression spring 46 engages, the other end of which engages at a fixed point relative to the valve housing 12 . On the side facing away from the crank 40 of the Ventilgehäu ses 12 is a further crank arm 43 with the axis 16 verbun, on which a spring 48 attacked in opposite directions to the spring 46 bean 48 , the other end of which also has a fixed position relative to the valve housing Point is attached.

Fig. 15 shows a combustion chamber 50 of a combustion engine, with two gas exchange channels 52 and 54 , the mouth of which is provided in the combustion chamber 50 with a poppet valve 56 and 58 , respectively. The charge exchange channel 52 extends between an air distributor 60 and the poppet valve 56 serving as an inlet valve; it has a length l 1. The charge exchange channel 54 runs between the poppet valve 58 serving as an outlet valve and an exhaust manifold 62 ; he sits the length 12 . A freely controllable valve 10 , which corresponds to the valve shown in FIG. 1 and can be operated by the method according to the invention, is located upstream of the inlet valve in the gas exchange channel 52 .

In principle, however, it is also possible, and explained with reference to FIGS. 7 to 9 above, to operate the poppet valves 56 and / or 58 just in accordance with the method according to the invention.

The lengths l 1 and / or l 2 can be chosen so that the natural frequency of the gas oscillation in each of these charge exchanges is channeled, in order to use gas-dynamic interactions in relation to the charge exchange, is matched to a specific frequency of the charge exchange of the respective combustion chamber. So in a particularly advantageous embodiment, the length l₁ of the suction channel is matched to high engine speeds, so that, for. B. at high speeds, a swinging tube charging takes place when the valve 10 is always held in the opening position for relief. At low speeds, the valve movement is then reactivated to improve the gas exchange.

Claims (28)

1. A method for controlling the gas exchange of internal combustion engines by means of valves, a valve being opened and closed at least once per working cycle in at least one gas exchange channel by moving a valve body relative to a valve housing such that part of the valve movement takes place in a closing region of the valve housing, in which the distance between the valve body and the valve housing is constantly limited to the minimum tolerance required for the relative movement between the valve housing and the closing body, while the other part of the movement of the valve body takes place in an opening area and the flow cross section of this valve changes suddenly when the valve body happens at high speed a control edge on the valve body that separates the closing area from the opening area, characterized in that during the opening movement and during the closing movement this s valve, the valve body is accelerated and then decelerated so that the control edge passes at high speed at adjustable control times. 2. The method according to claim 1, characterized in net that the valve body to a halt after its delay stood comes. 3. Method according to one of the preceding claims che, characterized in that the valve body around a transverse to the flow direction of this valve Axis rotates. 4. The method according to any one of the preceding claims che, characterized in that the valve body at Open and close moved in the same direction. 5. The method according to any one of claims 1 to 3, because characterized in that the opening movement of this valve is opposite to the closing movement. 6. The method according to any one of the preceding claims che, characterized in that the kinetic energy of the Valve body in its delay from an energy supply cher added and to accelerate the valve body is used again. 7. The method according to any one of the preceding claims che, characterized in that it controls a valve that in addition to a valve closing the combustion chamber in whose charge exchange channel is arranged. 8. The method according to claim 7, characterized in net that the valve controlled by him as an additional valve high engine speeds remain in the open position. 9. Device for carrying out the method one of claims 1 to 8, with a valve housing and egg  nem movable relative to the valve housing by a drive Valve body, the valve housing having an opening and has a closing area by a control edge are separated from each other at which the flow cross cut in the valve housing changes suddenly and in the lock the distance between the valve body and valve housing constant on that for the relative movement between Ven the minimum distance between the housing and the closing body tolerance is limited, characterized in that the Drive is suitable to accelerate the valve body movement and a delay phase movement movement set to subject such that the valve body the tax edge at high speed at a freely selectable time point happens. 10. The device according to claim 9 for implementation of the method according to one of claims 1, 2 or of the agents cash or directly related claims 5 to 8, because characterized in that the valve body moves linearly bar is slider. 11. The device according to claim 9 for implementation of the method according to one of claims 1, 2 or of the agents cash or directly related claims 5 to 8, because characterized in that the valve body an axially ver sliding poppet valve. 12. The device according to claim 9 for implementation of the method according to one of claims 3 or 4, characterized characterized in that the valve body by a transverse to the flow direction of the valve housing rotating axis in this is stored. 13. The apparatus according to claim 12, characterized records that the valve body has a rotatable valve flap is.   14. The apparatus of claim 13, wherein the Opening movement and closing movement counter to each other opposite direction, characterized in that the valve flap in the closed position the one turn axis containing, transverse to the flow axis Closing level is located and with its edge in all positions such a distance on all sides in the plane of the flap Housing complies with this during operation expected thermal expansion can not be overcome that the circumferential area of each partial surface on the housing one assigned to the stop edge brought up to the axis of rotation is and that these stop edges on different sides the valve flap is arranged and this as the end face seal are assigned. 15. The device according to one of claims 9 to 14 to carry out the method according to claim 6, characterized ge indicates that the valve body as an energy store Vibration system is assigned. 16. The apparatus according to claim 15, characterized records that the vibration system around mechanical springs sums up. 17. Device according to one of claims 15 or 16, characterized in that it comprises a device, which is capable of losing energy when moving this Compensate valve. 18. The apparatus according to claim 17, characterized records that the device is suitable, the energy ver compensate for every valve movement. 19. Device according to one of claims 17 to 18, characterized in that the valve body with springs a spring-mass system, which is about the Mit position between the two end positions of the valve body  is capable of vibrating at a frequency whose half-swing duration of the desired duration of movement between the two End positions corresponds to devices for supplying energy are present, the loss of energy by damping the Compensate for movement of the closing body from end position to end position chen, and that in the respective end position of the valve body Lock is assigned. 20. Device according to one of claims 18 or 19, characterized in that it has a device for includes electromagnetic energy supply. 21. Device according to one of claims 18 or 19, characterized in that it has a device for pneumatic power supply includes. 22. Device according to one of claims 18 or 19, characterized in that it has a device for hy drastic energy supply includes. 23. The device according to one of claims 9 to 22, characterized in that it is in one with the combustion chamber connected charge exchange channel of an internal combustion engine is ordered and the natural frequency of the gas vibration in the Line between the opening of this section and the Combustion chamber closing valve of the engine, for use gas dynamic interactions in relation to the charge change, to a certain frequency of the charge change of the resp is matched to the combustion chamber. 24. The device according to claim 23, characterized records that the freely controllable valve the inlet valve is connected upstream. 25. The device according to claim 23, characterized records that the freely controllable valve is the inlet valve is.   26. The device according to one of claims 9 to 13 or 15 to 24, characterized in that for sealing of the closing area at least in selected positions of the Valve body on the valve housing labyrinthine depressions are provided. 27. The device according to one of claims 12 or 13, characterized in that for sealing the closing gate labyrinthine indentations on the valve body hen are. 28. The apparatus of claim 13 and one of the Claims 26 or 27, characterized in that the Front side of the rotatable flap labyrinthine depressions having.