JP2008286031A - High pressure fuel pump and engine components - Google Patents

Abstract

A high-pressure fuel pump that is driven using the rotational power of a camshaft (17B) of an engine and supplies high-pressure fuel directly to an injector that injects high-pressure fuel directly into a combustion chamber of the engine. The manufacturing cost can be reduced by reducing the number of points.
A pump body 20 of a high-pressure fuel pump 4 is integrally formed with an engine component (13) attached to a cylinder head 12 of an engine 10, and a guide portion of a plunger 33 is provided on the pump body 20. An iron-based metal part (31) having a mounting portion 31b for 31a and a check valve 50 for high-pressure fuel discharge is embedded.
[Selection] Figure 5

Description

  The present invention relates to a high-pressure fuel pump that supplies high-pressure fuel to an injector that is driven using the rotational power of a camshaft of an engine and injects high-pressure fuel directly into a combustion chamber of the engine.

  The present invention also relates to an engine component attached to a cylinder head of the engine. The engine is mounted with an injector that directly injects high-pressure fuel into the combustion chamber and a high-pressure fuel pump for supplying high-pressure fuel to the injector.

  In general, in the case of a direct injection engine, the fuel delivered from a fuel tank is introduced into a pressurizing chamber of a plunger type high pressure fuel pump, and the plunger of this high pressure fuel pump is linearly reciprocated by a drive cam. After pressurizing the fuel in the pressurizing chamber, it is stored in a delivery pipe, the high-pressure fuel in the delivery pipe is supplied to the injector, and is directly injected from the injector into the combustion chamber of the engine. (For example, refer to Patent Document 1).

  A drive cam for driving a plunger of a high-pressure fuel pump is generally formed integrally with a cam shaft mounted on an engine or attached to be rotatable.

  In the situation where the cam nose is retracted from the plunger of the high-pressure fuel pump as the drive cam rotates integrally with the camshaft, the plunger moves downward and the volume of the pressurizing chamber is expanded (intake stroke) to reduce the pressure. Fuel is sucked into the pressurized chamber from the pipe. On the other hand, in a situation where the cam nose of the drive cam contacts the plunger of the high-pressure fuel pump, the plunger moves upward to reduce the volume of the pressurizing chamber (pressurization stroke).

The high pressure fuel pump has a structure in which a plunger guide cylinder, a plunger, an electromagnetic spill valve, a check valve and the like are assembled to a pump body having a pressurizing chamber. Such a high-pressure fuel pump is attached to, for example, a cylinder head cover of an engine using a bolt or the like.
JP-A-10-176678

  In the above conventional example, the high-pressure fuel pump is a single product, and is externally attached to an engine cylinder head cover or the like.

  In this high-pressure fuel pump, a seal member for preventing fuel leakage is frequently used, and it is necessary to finish the mating surfaces of the parts on which the seal member is arranged with high precision. The manufacturing cost is increased due to the need for a special and expensive material having excellent breakage resistance. Therefore, some measures are required to meet the recent demand for cost reduction of the high-pressure fuel pump.

  The present invention relates to a high-pressure fuel pump that is driven by the rotational power of a camshaft of an engine and supplies high-pressure fuel to an injector that directly injects high-pressure fuel into a combustion chamber of the engine. The purpose is to enable cost reduction.

  It is another object of the present invention to reduce the manufacturing cost of a high-pressure fuel pump by integrally forming a pump body of a high-pressure fuel pump in an engine component attached to a cylinder head of the engine. Yes.

  The present invention relates to a plunger-type high-pressure fuel pump that is driven by the rotational power of a camshaft of an engine and supplies high-pressure fuel to an injector that directly injects high-pressure fuel into a combustion chamber of the engine. An iron-based metal part having a plunger guide part and a high-pressure fuel discharge check valve mounting part is embedded in the pump body and integrally formed with engine components attached to the cylinder head of the engine. It is characterized by that.

  In general, a plunger-type high-pressure fuel pump is driven by a drive cam attached to an engine camshaft, pressurizes fuel supplied from a fuel tank and stores it in a delivery pipe. The high pressure fuel is directly injected from the injector into the combustion chamber of the engine.

  Examples of the engine component include a cylinder head cover attached to the cylinder head, a cam cap attached to the cylinder head, a timing chain cover attached to the front wall of the cylinder head and the cylinder block, or an intake manifold attached to the cylinder head. Is mentioned.

  Thus, if the pump body of the high-pressure fuel pump is formed integrally with the engine components as described above, the number of parts of the high-pressure fuel pump can be reduced.

  Moreover, because the pump body integrated with the engine component parts is embedded with iron-based metal parts having a plunger guide part and a high-pressure fuel discharge check valve mounting part provided in the high-pressure fuel pump, the pump body and the iron system It becomes possible to further reduce the number of parts of the high-pressure fuel pump, such as eliminating the need to dispose a seal member at the joint with the metal part.

  In particular, in an iron-based metal part, the wear resistance of the plunger sliding surface in the guide portion can be sufficiently ensured, and the attachment strength of the check valve to the mounting portion can be sufficiently ensured.

  Further, the present invention is an engine component attached to a cylinder head of an engine, and a pump body in a plunger-type high-pressure fuel pump that is driven at a predetermined position by using the rotational power of a camshaft of the engine Are integrally formed, and an iron-based metal part having a sliding guide portion of the plunger and a mounting portion for a check valve for high-pressure fuel discharge is embedded in the pump body.

  In general, a plunger-type high-pressure fuel pump is driven by a drive cam attached to an engine camshaft, pressurizes fuel supplied from a fuel tank and stores it in a delivery pipe. The high pressure fuel is supplied to the injector and directly injected from the injector into the combustion chamber of the engine.

  According to this configuration, the engine component is an existing component attached to the engine, and the pump body of the high-pressure fuel pump is integrally formed therewith, so the number of parts of the high-pressure fuel pump can be reduced. become.

  In addition, since the iron body metal parts having the sliding guide portion of the plunger provided in the high pressure fuel pump and the mounting portion of the check valve for high pressure fuel discharge are embedded in the pump body integrated with the engine component parts, It becomes possible to further reduce the number of parts of the high-pressure fuel pump, such as eliminating the need to dispose a seal member at the contact portion with the iron-based metal part.

  In particular, in an iron-based metal part, the wear resistance of the plunger sliding surface in the guide portion can be sufficiently ensured, and the attachment strength of the check valve to the mounting portion can be sufficiently ensured.

  Preferably, the engine component is a molded product manufactured by flowing a molten material into a predetermined mold and solidifying, and the iron-based metal part is positioned and arranged at a predetermined position in the mold. It is embedded in the pump body by flowing the molten material in a state.

  As the form of molding, when the engine component is a light alloy such as an aluminum alloy or a magnesium alloy, it is considered to be cast, and the engine component is a synthetic resin such as engineering plastic. In some cases, injection molding may be considered.

  In this way, it is possible to easily perform the manufacturing mode when the pump body is integrally formed with the engine component and the embedding mode of the iron-based metal component, which is excellent in productivity and manufacturing cost. It is advantageous in suppressing

  Preferably, the engine component is a light alloy cylinder head cover.

  Thus, the cylinder head cover specified as the engine component is originally arranged so as to cover the camshaft mounted on the cylinder head.

  Here, if the drive cam for driving the plunger is formed integrally with the cam shaft, the degree of freedom in design for associating the arrangement of the drive cam with respect to the cam shaft and the arrangement of the pump body with respect to the cylinder head cover is increased. Other engine components include a cam cap attached to the cylinder head, a timing chain cover attached to the front wall of the cylinder head and the cylinder block, an intake manifold attached to the cylinder head, and the like.

  Since the high-pressure fuel pump according to the present invention has the components integrated with the engine components, the number of components can be reduced, and the manufacturing cost can be reduced.

  In addition, since the engine component according to the present invention integrally forms the pump body of the high-pressure fuel pump, the number of components of the high-pressure fuel pump can be reduced, and the manufacturing cost of the high-pressure fuel pump can be reduced. This is advantageous for reduction.

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 to 13.
Embodiment 1
1 to 5 show a first embodiment of the present invention. Prior to the description of the features of the present invention, a schematic configuration of a fuel supply system used in a direct injection engine to which the present invention is applied will be described with reference to FIG.

  As shown in FIG. 1, this fuel supply system mainly includes a fuel tank 1, a feed pump 2, a pressure regulator 3, a high pressure fuel pump 4, a delivery pipe 5, an injector 6, a low pressure fuel pipe 7, a high pressure fuel pipe 8, and a return. Includes piping 9 and the like.

  The feed pump 2 feeds fuel from the fuel tank 1. The pressure regulator 3 returns the fuel in the low-pressure fuel pipe 7 to a predetermined pressure or less by returning the fuel in the low-pressure fuel pipe 7 to the fuel tank 1 when the fuel pressure in the low-pressure fuel pipe 7 exceeds a predetermined pressure. To maintain. The high pressure fuel pump 4 pressurizes the fuel sent out by the feed pump 2 and stores it in the delivery pipe 5. The delivery pipe 5 supplies high pressure fuel stored inside to the injector 6. The injector 6 directly injects the high-pressure fuel in the delivery pipe 5 into each combustion chamber 10 a of the engine 10.

  A return pipe 9 is connected to the delivery pipe 5 via a relief valve 5a. The relief valve 5a is opened when the fuel pressure in the delivery pipe 5 exceeds a predetermined pressure, and a part of the fuel stored in the delivery pipe 5 is returned to the fuel tank 1 through the return pipe 9. The fuel pressure in the delivery pipe 5 is prevented from excessively rising.

  The low pressure fuel pipe 7 is provided with a pulsation damper 7 a for suppressing fuel pressure pulsation in the low pressure fuel pipe 7 when the high pressure fuel pump 4 is operated.

  The number of injectors 6 is the same as the number of cylinders of the engine 10. Since the fuel supply system of the illustrated example is configured to include four injectors 6, the type of the engine 10 is a type used for a four-cylinder gasoline engine.

  The engine 10 includes at least a cylinder block 11, a cylinder head 12, a cylinder head cover 13, a plurality of cam caps 14, and a timing chain cover 15, as shown in FIGS. The cylinder head cover 13, the plurality of cam caps 14, and the timing chain cover 15 are all attached to the cylinder head 12.

  In this type of engine 10, the intake camshaft 17A and the exhaust camshaft 17B rotate once through the timing chain 16 during one cycle, that is, every time the crankshaft (not shown) rotates twice.

  By providing the exhaust camshaft 17B with a drive cam 18 for driving the high-pressure fuel pump 4, the high-pressure fuel is discharged from the high-pressure fuel pump 4 twice during one cycle of the engine 10, and the cylinder Each fuel injection is performed from each injector 6 provided for each time.

  The drive cam 18 is provided with two cam noses 18 a and 18 a with an angular interval of 180 ° around the rotation axis of the exhaust camshaft 13. However, the number of the cam noses 18a is not limited and is arbitrary.

  Next, the configuration of the high-pressure fuel pump 4 will be described with reference to FIGS. 1 and 4.

  As shown in FIG. 1 and FIG. 4, the high-pressure fuel pump 4 of this embodiment is generally known as a plunger type, but mainly includes a pump body 20, a pump unit 30, an electromagnetic spill valve 40, a check valve. 50 is comprised.

  The pump body 20 is formed integrally with a cylinder head cover 13 that is one of the components constituting the engine 10. Since this point is a part to which the features of the present invention are applied, it will be described in detail later.

  The pump unit 30 mainly includes a cylinder 31, a pressurizing chamber 32, a plunger 33, a lifter 34, and the like.

  The cylinder 31 has a plunger guide portion 31a into which the plunger 33 is slidably inserted, and a mounting portion 31b to which the check valve 50 is mounted. The cylinder 31 is embedded in the pump body 20 formed integrally with the cylinder head cover 13. This point is also a part to which the features of the present invention are applied, and will be described in detail later.

  The pressurizing chamber 32 is provided on the upper end side of the plunger guide portion 31 a and communicates with the feed pump 2 through the low-pressure fuel pipe 7 and communicates with the delivery pipe 5 through the high-pressure fuel pipe 8. Yes.

  The plunger 33 is a solid shaft body, and is inserted into the through hole of the plunger guide portion 31a of the cylinder 31 so as to be slidable in the axial direction.

  The lifter 34 is formed in a bottomed cylindrical shape, and its outer periphery is inserted into the lower bulging portion 21 of the pump body 20 so as to be slidable in the axial direction. The lower end of the plunger 33 is disposed inside the lifter 34, and the retainer 35 and the coil spring 36 are accommodated. The lower surface of the lifter 34 is brought into contact with the drive cam 18 by the elastic extension force of the coil spring 36. It has become.

  As an operation of the pump unit 30, the plunger 33 is reciprocated in the axial direction in the cylinder 31 by receiving a pressing force by the cam noses 18 a, 18 a of the rotating drive cam 18, and the volume of the pressurizing chamber 32 is increased. The fuel is pressurized by reducing the pressure. The fuel leaked from the gap between the cylinder 31 and the plunger 33 is returned to the return pipe 9 via the fuel discharge pipe 9a (shown by a broken line in FIG. 1).

  The electromagnetic spill valve 40 mainly includes an electromagnetic solenoid 41, a bobbin 42, a core 43, an armature 44, a poppet valve 45, a seat body 46, a coil spring 47, a valve body 48, and the like.

  The electromagnetic spill valve 40 is mounted on the upper side of the pump body 20, and controls communication between the low-pressure fuel pipe 7 and the pressurizing chamber 32 by controlling energization to the electromagnetic solenoid 41. The valve body 48 of the electromagnetic spill valve 40 is provided with a connector 49 to which a power supply harness is connected.

  Specifically, as the operation of the electromagnetic spill valve 40, when the energization of the electromagnetic solenoid 41 is stopped, the poppet valve 45 opens the through hole of the seat body 46 by the urging force of the coil spring 47, and the low pressure fuel pipe 7 communicates with the pressurizing chamber 32. On the other hand, when the electromagnetic solenoid 41 is energized, the armature 44 moves toward the core 43 against the urging force of the coil spring 47, whereby the poppet valve 45 closes the through hole of the seat body 46, and the low pressure fuel pipe 7 and the pressurizing chamber 32 are shut off (state shown in FIG. 4).

  The check valve 50 mainly includes a valve body 51, a seat body 52, a valve body 53, and a coil spring 54.

  The check valve 50 is moved to a position where the valve body 53 moves away from the seat body 52 against the biasing force of the coil spring 54 when the pressure of the fuel pumped from the pressurizing chamber 32 exceeds a predetermined value. As a result, the check valve 50 is opened, and the high-pressure fuel pumped from the pressurizing chamber 32 is supplied to the delivery pipe 5 through the high-pressure fuel pipe 8.

  Next, the operation of the high pressure fuel pump 4 will be described.

  When the plunger 33 moves in the direction in which the volume of the pressurizing chamber 32 increases (intake stroke) when the electromagnetic spill valve 40 is in the open state, that is, in the communication state, the fuel fed from the feed pump 2 is low-pressure fuel piping. 7 and is sucked into the pressurizing chamber 32.

  On the other hand, when the plunger 33 moves in the direction in which the volume of the pressurizing chamber 32 contracts (pressurization stroke) in the closed state, that is, the shut-off state of the electromagnetic spill valve 40, the fuel pressure in the pressurizing chamber 32 increases. When the fuel pressure reaches a predetermined value, the check valve 50 is opened, and high-pressure fuel is discharged toward the delivery pipe 5 through the high-pressure fuel pipe 8.

  The fuel discharge amount in the high-pressure fuel pump 4 is adjusted by controlling the closing period of the electromagnetic spill valve 40 in the pressurization stroke. That is, if the valve closing start time of the electromagnetic spill valve 40 is advanced and the valve closing period is lengthened, the fuel discharge amount increases. If the valve closing start time of the electromagnetic spill valve 40 is delayed and the valve closing period is shortened, the fuel discharge amount decreases. To do. That is, the fuel pressure in the delivery pipe 5 is controlled by adjusting the fuel discharge amount of the high-pressure fuel pump 4.

  Here, the characteristic part of this invention is demonstrated.

  In short, as shown in FIG. 5, the pump body 20 of the high-pressure fuel pump 4 is formed integrally with the cylinder head cover 13 which is one of the components of the engine 1, and the cylinder of the high-pressure fuel pump 4 is formed in the pump body 20. 31 is embedded.

  The cylinder head cover 13 is generally manufactured by casting using a light alloy such as an aluminum alloy or a magnesium alloy as a material.

  This casting is such that a molten material is poured into a mold and solidified. Therefore, although not shown, the above-described cylinder head cover 13 is manufactured by providing a cavity for securing the pump body 20 in the mold and positioning the cylinder 31 in the cavity. What should I do?

  In the case of the pump body 20 formed integrally with the cylinder head cover 13, the inner bulge portion 21 bulged and formed in a predetermined area on the inner surface side of the cylinder head cover 13 and the predetermined area on the outer surface side of the cylinder head cover 13. The outer bulging portion 22 is formed to protrude.

  The inner bulging portion 21 of the pump body 20 has a substantially cylindrical shape, and the pump portion 30 of the high-pressure fuel pump 4 is incorporated therein.

  The outer bulging portion 22 of the pump body 20 has a substantially cylindrical shape, and mounting portions 22a and 22b to which the electromagnetic spill valve 40 and the low pressure fuel pipe 7 of the high pressure fuel pump 4 are mounted are provided at predetermined positions. ing.

  The mounting portion 22 a for the electromagnetic spill valve 40 is an axial hole that communicates with the plunger guide portion 31 a in the cylinder 31 inside the pump body 20. The axial hole as the mounting portion 22a has a stepped shape by having a large diameter on the opening side, and the cylindrical boss portion 48a of the valve body 48 of the electromagnetic spill valve 40 is formed in the large opening on the opening side. Are inserted, and the seat body 46 and the poppet valve 45 of the electromagnetic spill valve 40 are slidably inserted into the small-diameter hole. And the collar part 48b of the valve body 48 is couple | bonded with a suitable fastening member (illustration omitted) in the state contact | abutted to the upper end surface of the opening part periphery of the axial direction hole in the mounting part 22a.

  The mounting portion 22b for the low-pressure fuel pipe 7 is a female screw hole that is formed to penetrate in the radial direction so as to communicate with the mounting portion 22a formed of the axial hole and has a thread groove formed on the inner peripheral surface. ing. The low pressure fuel pipe 7 is screwed into the female screw hole as the mounting portion 22b.

  The cylinder 31 embedded in the pump body 20 formed integrally with the cylinder head cover 13 includes a plunger guide portion 31a and a mounting portion 31b for the check valve 50.

  The plunger guide portion 31a in the cylinder 31 is a through hole penetrating in the axial direction, and the plunger is slidably inserted therein.

  The mounting portion 31b of the check valve 50 in the cylinder 31 is a radial hole that communicates with the plunger guide portion 31a in the cylinder 31, and a thread groove is formed on the inner peripheral surface of the mounting portion 31b. The valve body 51 of the check valve 50 is screwed into the female screw hole as the mounting portion 31b.

  The cylinder 31 is a ferrous metal such as stainless steel. This is because the wear resistance of the sliding surface of the plunger 33 in the guide portion 31a and the mounting strength (tightening axial force at the time of screwing) of the check valve 50 to the mounting portion 31b are ensured sufficiently and sufficiently.

  If the cylinder 31 is formed of the same material (light alloy in this embodiment) as the pump body 20, the guide portion 31 a is worn at an early stage and fuel leaks from the sliding gap with the plunger 33. In addition to being easy to use, there is a concern that shaving powder is generated when the check valve 50 is screwed and mixed into the high-pressure fuel discharged to the delivery pipe 5 side. That is, if the cylinder 31 is made of an iron-based metal part, the above-mentioned worry is eliminated.

  In the first embodiment described above, the number of parts of the high-pressure fuel pump 4 can be reduced by forming the pump body 20 of the high-pressure fuel pump 4 integrally with the cylinder head cover 13.

  In addition, since the cylinder 31 as an iron-based metal part is embedded in the pump body 20 integrated with the cylinder head cover 13, there is no need to place a seal member on the coupling surface between the pump body 20 and the cylinder 31. The number of parts of the fuel pump 4 can be further reduced.

  For these reasons, it is possible to reduce the manufacturing cost of the high-pressure fuel pump 4 although there is a concern that the manufacturing cost of the cylinder head cover 13 is slightly increased compared to the conventional one.

Embodiment 2
Embodiment 2 of the high-pressure fuel pump 4 according to the present invention will be described in detail with reference to FIG. 6, for example. In the second embodiment, the configuration of the high-pressure fuel pump 4 is the same as that of the first embodiment described above. Therefore, in FIG. 6, some components (22a, 22b, 30, 31, 31a, 31b, etc.) are not described, but refer to FIGS. 4 and 5 for such components.

  In short, in the second embodiment, the pump body 20 of the high-pressure fuel pump 4 is integrated with the cam cap 14 of the engine 10, and the cylinder 31 of the high-pressure fuel pump 4 is connected to the pump body 20 formed integrally with the cam cap 14. An embedded example is given.

  In this case, as shown in FIG. 6, the cam cap 14 has a large shape so that, for example, two journal portions of each of the camshafts 17A and 17B can be supported. The pump body 20 is formed in a region corresponding to the drive cam 18 provided on the exhaust camshaft 17B in the large cam cap 14.

  Then, the high pressure fuel pump 4 is completed by assembling the pump body 30, the electromagnetic spill valve 40 and the check valve 50 shown in FIG. 4 to the pump body 20 and the cylinder 31 integrally formed with the cam cap 14. In this state, since the high-pressure fuel pump 4 penetrates the cylinder head cover 13, the following is devised.

  That is, a through hole 13 a is provided in a predetermined region of the cylinder head cover 13, and the upper portion of the high pressure fuel pump 4 is allowed to protrude from the through hole 13 a to the outside of the cylinder head cover 13.

  Further, in the case of the second embodiment, the valve body 51 of the check valve 50 is L-shaped, and the connector 49 of the electromagnetic spill valve 40 is protruded upward from the center of the upper end surface of the valve body 48. The outer diameter portion of the pump body 20 of the high-pressure fuel pump 4 is easily fitted into the through hole 13 a of the cylinder head cover 13. In addition, although not shown in figure for fitting with the through-hole 13a and the outer diameter part of the pump body 20, an appropriate sealing member is mounted and sealed.

  Incidentally, the cam cap 14 is generally manufactured by casting using a light alloy such as an aluminum alloy or a magnesium alloy.

  This casting is such that a molten material is poured into a mold and solidified. Therefore, although not shown in the figure, a cavity for securing the pump body 20 is provided in the mold, and the cylinder 31 made of an iron-based metal material is positioned and arranged in the cavity. The cam cap 14 may be manufactured.

  In the case of the pump body 20 formed integrally with the cam cap 14 as described above, the inner bulging portion 21 bulged and formed in a predetermined area on the inner surface side of the cam cap 14 and the bulging in a predetermined area on the outer surface side of the cam cap 14 The outer bulging portion 22 is formed to protrude.

  The inner bulging portion 21 of the pump body 20 has a substantially cylindrical shape, and the pump portion 30 of the high-pressure fuel pump 4 is incorporated therein.

  The outer bulging portion 22 of the pump body 20 has a substantially cylindrical shape, and mounting portions 22a and 22b to which the electromagnetic spill valve 40 and the low pressure fuel pipe 7 of the high pressure fuel pump 4 are mounted are provided at predetermined positions. ing. About the form for driving these mounting parts 22a and 22b and the high-pressure fuel pump 4, since it is the same as that of the said Embodiment 1, detailed description about these is omitted.

  In the second embodiment described above, the number of parts of the high-pressure fuel pump 4 can be reduced by forming the pump body 20 of the high-pressure fuel pump 4 integrally with the cam cap 14.

  In addition, since the cylinder 31 as an iron-based metal part is embedded in the pump body 20 integrated with the cam cap 14, there is no need to place a seal member on the coupling surface between the pump body 20 and the cylinder 31. The number of parts of the fuel pump 4 can be further reduced.

  For these reasons, it is possible to reduce the manufacturing cost of the high-pressure fuel pump 4 although there is a concern that the manufacturing cost of the cam cap 14 will be slightly higher than the conventional one.

Embodiment 3
Embodiment 3 of the high-pressure fuel pump 4 according to the present invention will be described in detail with reference to FIGS. 7 and 8, for example.

  In short, in Embodiment 3, the pump body 20 of the high-pressure fuel pump 4 is integrated with the timing chain cover 15 of the engine 10, and the cylinder of the high-pressure fuel pump 4 is integrated with the pump body 20 formed integrally with the timing chain cover 15. The example which embedded 31 is given.

  Then, the high pressure fuel pump 4 is completed by assembling the pump portion 30, the electromagnetic spill valve 40 and the check valve 50 to the pump body 20 and the cylinder 31 integrally formed with the timing chain cover 15.

  Specifically, the timing chain cover 15 is generally manufactured by casting using a light alloy such as an aluminum alloy or a magnesium alloy.

  This casting is such that a molten material is poured into a mold and solidified. Therefore, although not shown in the figure, a cavity for securing the pump body 20 is provided in the mold, and the cylinder 31 made of an iron-based metal material is positioned and arranged in the cavity. The timing chain cover 15 may be manufactured.

  In the case of the pump body 20 formed integrally with the timing chain cover 15, the inner bulge portion 21 bulged and formed on a predetermined area on the inner surface side of the timing chain cover 15, and the predetermined outer surface side of the timing chain cover 15. It has the outer bulging part 22 bulged and formed in the region.

  The inner bulging portion 21 of the pump body 20 has a substantially cylindrical shape, and the pump portion 30 of the high-pressure fuel pump 4 is incorporated therein.

  The outer bulging portion 22 of the pump body 20 has a substantially cylindrical shape, and mounting portions 22a and 22b to which the electromagnetic spill valve 40 and the low pressure fuel pipe 7 of the high pressure fuel pump 4 are mounted are provided at predetermined positions. ing. Since the mounting portions 22a and 22b are the same as those in the first embodiment, detailed description thereof is omitted.

  By the way, the high-pressure fuel pump 4 is devised as follows regarding the drive system.

  As shown in FIG. 8, the cam gear 17A1 is also used as the drive cam 18 by providing a cam nose 18a on the end face of the cam gear 17A1 provided integrally with the front end of the intake camshaft 17A as the drive cam 18. Yes.

  Therefore, the outer end of the plunger 33 of the high-pressure fuel pump 4 is brought into contact with the outer diameter side of the end face of the cam gear 17A1 from the axial direction. As a result, when the cam nose 18 a comes into contact with the outer end of the plunger 33 via the lifter 34 as the cam gear 19 rotates, the plunger 33 is pushed and the pressurizing chamber 32 is compressed.

  In the third embodiment described above, by forming the pump body 20 of the high-pressure fuel pump 4 integrally with the timing chain cover 15, the number of parts of the high-pressure fuel pump 4 can be reduced.

  In addition, since the cylinder 31 as an iron-based metal part is embedded in the pump body 20 integrated with the timing chain cover 15, it is not necessary to arrange a seal member on the coupling surface between the pump body 20 and the cylinder 31. The number of parts of the high-pressure fuel pump 4 can be further reduced.

  For these reasons, it is possible to reduce the manufacturing cost of the high-pressure fuel pump 4 although there is a concern that the manufacturing cost of the timing chain cover 15 is slightly increased compared to the conventional one.

  The timing chain cover 15 is a name for covering the timing chain 16, but is called a timing belt cover when a timing belt is used instead of the timing chain 16. That is, it means that the timing chain cover 15 and the timing belt cover are substantially the same parts even though the names are different.

Embodiment 4
Embodiment 4 of the high-pressure fuel pump 4 according to the present invention will be described in detail with reference to FIGS. 9 to 11, for example.

  In short, in the fourth embodiment, the pump body 20 of the high-pressure fuel pump 4 is integrated with the intake manifold 19 of the engine 10, and the cylinder 31 of the high-pressure fuel pump 4 is connected to the pump body 20 integrally formed with the intake manifold 19. An embedded example is given.

  The high pressure fuel pump 4 is completed by assembling the pump portion 30, the electromagnetic spill valve 40, and the check valve 50 to the pump body 20 and the cylinder 31 integrally formed with the intake manifold 19.

  Specifically, the intake manifold 19 is generally manufactured by casting using a light alloy such as an aluminum alloy or a magnesium alloy.

  This casting is such that a molten material is poured into a mold and solidified. Therefore, although not shown in the figure, a cavity for securing the pump body 20 is provided in the mold, and the cylinder 31 made of an iron-based metal material is positioned and arranged in the cavity. The intake manifold 19 may be manufactured.

  In the fourth embodiment, as shown in FIG. 9, when the pump body 20 is formed integrally with the intake manifold 19, the overhanging portion 19 a is provided on one end side in the intake passage arrangement direction in the engine manifold region of the intake manifold 19. The pump body 20 is disposed on the overhanging portion 19a.

  In the case of the pump body 20 formed integrally with the intake manifold 19, an inner bulge portion 21 bulged and formed in a predetermined region on the inner surface side of the outer wall portion of the bulge portion 19 a of the intake manifold 19, and a bulge portion of the intake manifold 19 It has the outer bulging part 22 bulged and formed in the predetermined area | region of the outer wall part in 19a.

  The inner bulging portion 21 of the pump body 20 has a substantially cylindrical shape, and the pump portion 30 of the high-pressure fuel pump 4 is incorporated therein.

  The outer bulging portion 22 of the pump body 20 has a substantially cylindrical shape, and mounting portions 22a and 22b to which the electromagnetic spill valve 40 and the low pressure fuel pipe 7 of the high pressure fuel pump 4 are mounted are provided at predetermined positions. ing. Since the mounting portions 22a and 22b are the same as those in the first embodiment, detailed description thereof is omitted.

  By the way, the drive system of the high-pressure fuel pump 4 is devised as follows.

  As shown in FIGS. 10 and 11, the drive cam 18 is configured such that a cam nose 18a is provided in the middle of the shaft 18b in the axial direction.

  The drive cam 18 is disposed in the projecting portion 19a of the intake manifold 19 in the vicinity of the lower opening of the inner bulged portion 21 of the pump body 20, and both axial ends of the shaft body 18b of the drive cam 18 are respectively rolled. It supports by the overhang | projection part 19a via the bearing (code | symbol abbreviation | omission).

  The cam noses 18 a and 18 a of the drive cam 18 arranged in this manner are brought into contact with the lower end portion of the plunger 33 via the lifter 34 of the pump unit 30 incorporated in the pump body 20.

  Furthermore, one shaft end of the shaft body 18b of the drive cam 18 protrudes to the outside from the protruding portion 19a, and a gear (or pulley) 60 is attached to the protruding one shaft end.

  The gear 60 is driven by an intake camshaft 17A via a chain (or belt) 61. That is, a gear portion (or pulley) 62 is provided along with the cam gear 17A1 at the front end of the intake camshaft 17A, and the chain 61 is wound around the gear portion 62 and the gear 60 of the drive cam 18. It is like that.

  That is, when the drive cam 18 is rotationally driven with the rotation of the intake camshaft 17A, the cam nose 19a of the drive cam 18 pushes the plunger 33 via the lifter 34 to compress the pressurizing chamber 32. .

  In the fourth embodiment described above, the number of parts of the high pressure fuel pump 4 can be reduced by forming the pump body 20 of the high pressure fuel pump 4 integrally with the intake manifold 19.

  And since the cylinder 31 as an iron-type metal part is embedded in the pump body 20 integrated with the intake manifold 19, it becomes unnecessary to arrange | position a sealing member on the coupling surface of the pump body 20 and the cylinder 31, etc. The number of parts of the high-pressure fuel pump 4 can be further reduced.

  For these reasons, it is possible to reduce the manufacturing cost of the high-pressure fuel pump 4 although there is a concern that the manufacturing cost of the intake manifold 19 is slightly increased compared to the conventional one.

-Embodiment 5
Embodiment 5 of the high-pressure fuel pump 4 according to the present invention will be described in detail with reference to FIGS. 12 and 13, for example.

  In the fourth embodiment, as described in the first embodiment, the pump body 20 of the high-pressure fuel pump 4 is integrated with the cylinder head cover 13 of the engine 10 and the cylinder 31 made of iron-based metal parts is embedded in the pump body 20. In addition, the delivery pipe 5 is also integrated with the cylinder head cover 13.

  That is, the delivery pipe 5 is connected to an injector 6 provided corresponding to each cylinder of the engine 10 as shown in FIG. Considering this, by providing a raised portion along the longitudinal direction of the cylinder head cover 13 (in the cylinder arrangement direction of the engine) on the outer surface of the cylinder head cover 13, a space for accumulating high-pressure fuel is secured inside the raised portion. Thus, the delivery pipe 5 is integrated with the cylinder head cover 13.

  The cylinder head cover 13 is further provided with mounting holes 13b for a plurality of injectors 6, and the injectors 6 are respectively mounted in the mounting holes 13b.

  In this case, the high pressure fuel pump 4 is configured by assembling the pump portion 30, the electromagnetic spill valve 40 and the check valve 50 to the pump body 20 of the cylinder head cover 13, and the check valve 50 and the delivery pipe 5 of the high pressure fuel pump 4 are connected. By connecting with the high-pressure fuel pipe 8 and individually connecting the delivery pipe 5 and each injector 6 with appropriate pipes, the fuel injection system can be integrated as one assembly.

  As a result, it becomes possible to simplify the handling and installation layout of the fuel injection system, and although there is a concern that the manufacturing cost of the cylinder head cover 13 is slightly higher than the conventional one, the fuel injection system Total cost reduction is possible.

  In addition, this invention is not limited only to the said embodiment, All the deformation | transformation and application included in the range equivalent to the claim and the said range are possible. Examples are given below.

  (1) In the first, second, and fifth embodiments, the drive cam 18 that drives the high-pressure fuel pump 4 is provided on the exhaust camshaft 17B. However, it can be installed on the intake camshaft 17A side. is there. In the third and fourth embodiments, the high-pressure fuel pump 4 is driven by using the rotational power of the intake camshaft 17A. However, the rotational power of the exhaust camshaft 17B is used. Is also possible.

  (2) In each of the above embodiments, an example is given in which the present invention is applied to engine components of a direct injection type four-cylinder gasoline engine. However, the number of cylinders of the engine 10 is arbitrary, and is not limited to a gasoline engine. The present invention can also be applied to components in engines such as diesel engines.

  (3) The cylinder head cover 13, the cam cap 14, and the timing chain cover 15 as engine components shown in the above embodiments can be injection molded using a synthetic resin such as engineering plastic. In such a case, the cylinder 31 as an iron-based metal part may be inserted into the cavity of the molding die to be used and molded.

  (4) In each of the above embodiments, the cylinder 31 embedded in the pump body 20 is exemplified by a one-piece structure in which the guide portion 31a of the plunger 33 and the mounting portion 31b of the check valve 50 are integrally formed. It is good also as a two piece structure which combined what formed separately.

  Also in this case, a two-piece cylinder (not shown) is embedded in the pump body 20 formed integrally with the engine components (13, 14, 15), so that the coupling surface between the two members constituting the cylinder is sealed. Will be. As a result, it is possible to contribute to a reduction in the manufacturing cost of the high-pressure fuel pump 4 as in the case of the one-piece structure cylinder 31 such as not having to arrange a seal member on the coupling surface.

It is a figure which shows schematic structure of the fuel supply system used as the application object of the high pressure fuel pump which concerns on this invention. 1 is an exploded perspective view schematically showing an engine equipped with Embodiment 1 of a high-pressure fuel pump according to the present invention. It is a side view of the assembly state of the engine shown in FIG. FIG. 3 is a cross-sectional view taken along line (4)-(4) in FIG. 3 and shows the configuration of the high-pressure fuel pump. It is a figure which shows the state which decomposed | disassembled the high pressure fuel pump of FIG. It is a disassembled perspective view of the engine carrying Embodiment 2 of the high-pressure fuel pump which concerns on this invention. It is a disassembled perspective view of the engine carrying Embodiment 3 of the high-pressure fuel pump which concerns on this invention. In Embodiment 3, it is sectional drawing which shows the drive system of a high pressure fuel pump. It is a disassembled perspective view of the engine carrying Embodiment 4 of the high-pressure fuel pump which concerns on this invention. In Embodiment 4, it is a side view which shows the drive system of a high pressure fuel pump. In Embodiment 4, it is sectional drawing which shows the drive system of a high pressure fuel pump. It is a disassembled perspective view of the engine carrying Embodiment 5 of the high-pressure fuel pump which concerns on this invention. In Embodiment 5, it is sectional drawing of an engine component (cylinder head cover).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel tank 4 High pressure fuel pump 6 Injector 10 Engine 10a Combustion chamber 12 Cylinder head 13 Cylinder head cover (engine component)
17B Exhaust camshaft 18 Drive cam 20 Pump body 21 Inner bulging part of pump body 22 Outer bulging part of pump body 30 Pump part 31 Cylinder (iron-based metal part)
31a Plunger guide portion in cylinder 31b Check valve mounting portion in cylinder 32 Pressurizing chamber 33 Plunger 40 Electromagnetic spill valve 50 Check valve

Claims (4)

A plunger-type high-pressure fuel pump that is driven by the rotational power of an engine camshaft and supplies high-pressure fuel to an injector that directly injects high-pressure fuel into a combustion chamber of the engine,
The pump body is integrally formed with engine components attached to the cylinder head of the engine,
A high-pressure fuel pump, wherein a ferrous metal part having a guide portion of the plunger and a mounting portion for a check valve for high-pressure fuel discharge is embedded in the pump body. Engine components attached to the cylinder head of the engine,
A pump body in a plunger-type high-pressure fuel pump that is driven using the rotational power of the camshaft of the engine is integrally formed at the predetermined position,
An engine component comprising an iron metal part having a guide part of the plunger and a mounting part for a check valve for high-pressure fuel discharge embedded in the pump body.   The engine component according to claim 2 is a molded product manufactured by flowing a molten material into a predetermined mold and solidifying, and the iron-based metal part is positioned at a predetermined position in the mold. An engine component that is embedded in a pump body by allowing a molten material to flow into the pump body.   The engine component according to claim 2 or 3, wherein the engine component is a light alloy cylinder head cover.

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