JP5218246B2 - High pressure fuel pump - Google Patents

Description

  The present invention relates to a high-pressure fuel pump, and more particularly to a high-pressure fuel pump including a roller lifter that reciprocates by a rotational movement of a drive cam.

  Generally, a high-pressure fuel pump includes a roller that slides in contact with a drive cam, a roller lifter that supports the roller, a lifter housing that accommodates the roller lifter in a reciprocating manner, and a pump body, and is sucked into the pump body. The fuel is discharged at a high pressure. In this high-pressure fuel pump, when the roller lifter reciprocates, a detent for preventing the rotation of the roller lifter relative to the lifter housing is provided so that the relative position between the drive cam and the roller does not shift.

  Conventionally, as this type of high-pressure fuel pump, a camshaft as a driving cam, a roller and a roller tappet as a roller lifter, a lift sleeve as a lifter housing, a pin mounted on the roller tappet, and this pin are guided. A longitudinal slit formed in the sliding sleeve, a fixing pin formed with a male screw to attach the sliding sleeve to the pump body, and a fitting pin arranged on the side facing the fixing pin are known. (For example, refer to Patent Document 1).

  In this high-pressure fuel pump, the sliding pin can be attached to and detached from the pump body by making the fixing pin and the fitting pin detachable, and the pin attached to the roller tappet can also be removed from the roller tappet. Makes it easy to replace when worn. In addition, by forming a longitudinal slit portion in the sliding sleeve and inserting a pin into the longitudinal slit portion, when the tappet with a roller reciprocates within the sliding sleeve, the relative rotation is prevented and the tappet with the roller The sliding sleeve is prevented from falling off.

  In this high-pressure fuel pump, the fixing pin and the fitting pin are detachable, the fixing sleeve and the fitting pin are provided so that the sliding sleeve can be attached and detached from the pump body, and further, the roller is provided by inserting the pin into the longitudinal slit portion. Relative rotation when the attached tappet reciprocates within the sliding sleeve is prevented. For this reason, the structure of the high-pressure fuel pump becomes complicated, the number of parts increases, and there is a problem in that it takes time for assembly and production efficiency may be reduced.

  As a conventional high-pressure fuel pump designed to solve such problems, as shown in FIG. 17, the structure is simplified and the production efficiency is improved as compared with the high-pressure fuel pump described in Patent Document 1 described above. What you are trying to do is known.

  In the high-pressure fuel pump 100, the lifter housing 101 is inserted into a mounting hole 110a and a guide groove 110b of a pump mounting part 110 provided in an engine (not shown), and is housed in a housing hole 101a in the lifter housing 101. The roller lifter 102 that moves, the roller 104 that is rotatably supported by the roller lifter 102, and a seal member 105 that seals oil from leaking from the drive cam 103 side to the outside through the accommodation hole 101a. And.

  Further, in the high pressure fuel pump 100, a guide groove 101b is provided in a side surface portion of the lifter housing 101, and a rotation preventing portion 106 formed in the roller lifter 102 is inserted into the guide groove 101b, so that the roller lifter 102 reciprocates. When moving, relative rotation is prevented from occurring in the receiving hole 101a.

JP-A-6-159192

  However, although the conventional high-pressure fuel pump 100 shown in FIG. 17 has fewer parts than the high-pressure fuel pump described in Patent Document 1, there is a structural defect. That is, in the high-pressure fuel pump 100 shown in FIG. 17, the seal member 105 is mounted in the seal groove 101c formed in the upper surface portion of the lifter housing 101 in order to prevent oil leakage. There is a problem that the member 105 has a special shape having no versatility, the efficiency of assembling the seal member 105 is lowered, and it is difficult to significantly improve the production efficiency.

  The present invention has been made to solve the above-described conventional problems, and can reduce the number of parts with a simple structure, can be configured with a highly versatile seal member, and has a high production efficiency. It is an object to provide a fuel pump.

In order to achieve the above object, a high-pressure fuel pump according to the present invention includes (1) a roller that is in sliding contact with a drive cam, a roller lifter that rotatably supports the roller, and a lifter housing that slidably supports the roller lifter. A pump body supported by the lifter housing, a spring that presses the roller lifter in the direction of the drive cam, a plunger that is slidably supported by the pump body and that forms a pressure chamber together with the pump body, A high-pressure fuel pump that discharges by increasing the pressure of the fuel sucked into the pressure chamber by reciprocating the plunger according to the rotational movement of the drive cam. The lifter housing has a through hole that slidably accommodates the stopper in the axial direction of the plunger. Formed, the lifter housing has an inner peripheral surface portion, the pump body has an outer peripheral surface portion in contact with the inner peripheral surface portion, and an annular groove is formed in either the inner peripheral surface portion or the outer peripheral surface portion, An annular seal member is mounted in the annular groove, the through hole is formed closer to the drive cam than the seal member , the lifter housing accommodates the roller lifter accommodation hole for accommodating the roller lifter, and the pump body. A pump body housing hole having a larger diameter than the roller lifter housing hole and communicating with the roller lifter housing hole, and an end portion of the through hole on the pump body side communicating with the pump body housing hole It is characterized by that.

With this configuration, an annular groove is formed in either the inner peripheral surface portion of the lifter housing or the outer peripheral surface portion of the pump body, and a seal member is attached to the annular groove. The structure is significantly simplified. As a result, assembly workability and parts management are improved and production efficiency is improved.
In addition, a through hole is formed in the lifter housing so as to be positioned closer to the drive cam than the seal member, and the rotation preventing portion of the roller lifter is slidably inserted into the through hole, so that a conventional high pressure fuel pump is used. The through-hole for preventing rotation is not formed so as to penetrate the flange portion of the lifter housing, and it is not necessary to use a seal member having a special shape. Further, since the rotation preventing portion is inserted into the through hole, the relative rotation of the roller lifter is reliably prevented with a simple structure.
When the roller lifter is housed in the roller lifter housing hole of the lifter housing, the roller lifter is directed toward the pump body housing hole, the roller lifter is inserted into the pump body housing hole, and the rotation stopper is inserted into the through hole. The roller lifter can be inserted into the hole. Thus, even if the rotation preventing portion of the roller lifter is formed integrally with the roller lifter, the roller lifter can be easily assembled in the roller lifter receiving hole.
Further, when the roller lifter is inserted into the pump body receiving hole, if the roller lifter is inclined so that the axis of the roller lifter is inclined with respect to the axis of the pump body receiving hole, the rotation preventing portion of the roller lifter is more easily connected to the through hole of the lifter housing. Can be inserted into the roller lifter receiving hole more easily.

In order to achieve the above object, the high-pressure fuel pump according to the present invention includes (2) a roller that is in sliding contact with the drive cam, a roller lifter that rotatably supports the roller, and a lifter housing that slidably supports the roller lifter. A pump body supported by the lifter housing, a spring that presses the roller lifter in the direction of the drive cam, a plunger that is slidably supported by the pump body and that forms a pressure chamber together with the pump body, A high-pressure fuel pump that discharges by increasing the pressure of the fuel sucked into the pressure chamber by reciprocating the plunger according to the rotational movement of the drive cam. The lifter housing has a through hole that slidably accommodates the stopper in the axial direction of the plunger. And the lifter housing has a flat part, the pump body has a contact part in contact with the flat part, and an annular groove is formed in one of the contact part and the flat part, An annular seal member is attached to the annular groove, the through hole is formed on the drive cam side of the seal member , the lifter housing accommodates the roller lifter accommodating hole for accommodating the roller lifter, and the pump body, A pump body housing hole having a diameter larger than the roller lifter housing hole and communicating with the roller lifter housing hole, and an end of the through hole on the pump body side communicating with the pump body housing hole It is characterized by.

With this configuration, an annular groove is formed in either the pump body abutting portion or the flat portion of the lifter housing, and a sealing member is attached to the annular groove. The structure is significantly simplified. As a result, assembly workability and parts management are improved and production efficiency is improved.
In addition, a through hole is formed in the lifter housing so as to be positioned closer to the drive cam than the seal member, and the rotation preventing portion of the roller lifter is slidably inserted into the through hole, so that a conventional high pressure fuel pump is used. The through-hole for preventing rotation is not formed so as to penetrate the flange portion of the lifter housing, and it is not necessary to use a seal member having a special shape. Further, since the rotation preventing portion is inserted into the through hole, the relative rotation of the roller lifter is reliably prevented with a simple structure.
When the roller lifter is housed in the roller lifter housing hole of the lifter housing, the roller lifter is directed toward the pump body housing hole, the roller lifter is inserted into the pump body housing hole, and the rotation stopper is inserted into the through hole. The roller lifter can be inserted into the hole. Thus, even if the rotation preventing portion of the roller lifter is formed integrally with the roller lifter, the roller lifter can be easily assembled in the roller lifter receiving hole.
Further, when the roller lifter is inserted into the pump body receiving hole, if the roller lifter is inclined so that the axis of the roller lifter is inclined with respect to the axis of the pump body receiving hole, the rotation preventing portion of the roller lifter is more easily connected to the through hole of the lifter housing. Can be inserted into the roller lifter receiving hole more easily.

  In the high-pressure fuel pump according to either (1) or (2), (3) the annular seal member is an O-ring.

  With this configuration, an annular groove is formed in either the inner peripheral surface portion of the body housing portion and the outer peripheral surface portion of the lifter housing, or in either the abutting portion of the pump body or the flat portion of the lifter housing. Since the ring can be mounted, versatility is improved, parts management is improved, and production efficiency is improved.

  In the method for assembling the high-pressure fuel pump according to any one of (1) to (4), (5) when the roller lifter is accommodated in the roller lifter accommodating hole of the lifter housing, the rotation preventing portion of the roller lifter is pumped A roller lifter assembly step for inserting the roller lifter into the pump body housing hole and inserting the roller lifter into the roller lifter housing hole in a state where the axis of the roller lifter is inclined with respect to the axis of the pump body housing hole toward the body housing hole side It is characterized by that.

  With this configuration, when the roller lifter is accommodated in the roller lifter accommodation hole of the lifter housing, the roller lifter is inserted into the pump body accommodation hole with the axis of the roller lifter inclined with respect to the axis of the pump body accommodation hole. The assembly work of the fuel pump is remarkably simplified, and the production efficiency of the high-pressure fuel pump is increased.

  According to the present invention, it is possible to provide a high-pressure fuel pump that has a simple structure, can reduce the number of parts, can be configured with a highly versatile seal member, and has high production efficiency.

It is a figure which shows typically the structure of the fuel supply apparatus with which the high pressure fuel pump which concerns on embodiment of this invention is applied. It is sectional drawing of the high pressure fuel pump which concerns on embodiment of this invention. It is sectional drawing which shows the AA cross section of FIG. It is a perspective view of the housing and roller lifter of the high-pressure fuel pump concerning the embodiment of the present invention. It is a side view of the roller lifter of the high-pressure fuel pump concerning the embodiment of the present invention. It is a bottom view of the roller lifter of the high-pressure fuel pump according to the embodiment of the present invention. It is sectional drawing which shows the BB cross section of FIG. It is sectional drawing which shows CC cross section of FIG. It is a side view of the housing of the high-pressure fuel pump concerning the embodiment of the present invention. It is sectional drawing which shows the DD cross section of FIG. It is sectional drawing of the high pressure fuel pump which concerns on embodiment of this invention, (a) shows the state which inserted the roller lifter in the pump body accommodation hole of the housing, (b) inserted the roller lifter in the roller lifter accommodation hole of the housing Shows the state. It is sectional drawing of the high pressure fuel pump which concerns on embodiment of this invention, and shows the state which the roller lifter fell. It is sectional drawing of the high pressure fuel pump which concerns on embodiment of this invention, and shows the state which the roller lifter raised. It is sectional drawing of the high pressure fuel pump which concerns on the 1st modification of embodiment of this invention. It is sectional drawing of the high pressure fuel pump which concerns on the 2nd modification of embodiment of this invention. It is sectional drawing of the high pressure fuel pump which concerns on the 3rd modification of embodiment of this invention. It is a disassembled perspective view of the conventional high-pressure fuel pump.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, the configuration will be described.
As shown in FIG. 1, the high-pressure fuel pump 7 according to the embodiment of the present invention constitutes a fuel supply device 5.

The high-pressure fuel pump 7 is mounted on an engine of a vehicle (not shown) and is configured to supply fuel into the combustion chamber of the engine at a high pressure. The oil pump 7 is driven by the engine and forms part of the engine. Oil is supplied and lubricated.
In addition, there is no restriction | limiting in particular about the kind of engine, For example, gasoline, such as an inline 4 cylinder, may be sufficient, and a diesel engine may be sufficient.

  The fuel supply apparatus 5 includes a fuel tank 6, a high-pressure fuel pump 7, four fuel injection valves 8, and an electronic control unit (ECU) 9.

  Further, the fuel supply device 5 suppresses pressure pulsation generated in the fuel path by the fuel injection of the fuel injection valve 8 provided in the low pressure fuel pipe 11 and the low pressure fuel pipe 11 connecting the fuel tank 6 and the high pressure fuel pump 7. A pulsation damper 12 for supplying fuel, a delivery pipe 13 for supplying fuel to each fuel injection valve 8, a high-pressure fuel pipe 14 for connecting the high-pressure fuel pump 7 and the delivery pipe 13, and a fuel stored in the delivery pipe 13. When the fuel pressure detected by the fuel pressure sensor 16 exceeds a predetermined pressure (MPa), a return pipe 15 for returning the fuel to the fuel tank 6, a fuel pressure sensor 16 for detecting the pressure (MPa) of the fuel in the delivery pipe 13 And a relief valve 17 that opens at a low angle.

  The fuel tank 6 includes a tank main body 21 that stores fuel supplied to the engine, a pressure regulator 22 that is accommodated in the tank main body 21 and is provided in the low-pressure fuel pipe 11, and adjusts the pressure of the fuel. It includes a feed pump 23 that supplies fuel to the high-pressure fuel pump 7 via the low-pressure fuel pipe 11, and a filter 24 that is provided between the pressure regulator 22 and the feed pump 23 and filters the fuel.

  As shown in FIG. 2, the high-pressure fuel pump 7 includes a pump body 31, a drive cam 32 that drives the pump body 31, an electromagnetic spill valve 33, a suction valve case 34, a discharge valve case 35, and a discharge valve case 35. And a check valve 36 housed in the housing. The high-pressure fuel pump 7 is attached to a pump mounting portion 18 provided in an engine component such as a cylinder head cover in the pump main body 31, and is supplied with oil by an oil supply device 40 to lubricate a sliding element or the like. Is to be lubricated.

  As shown in FIG. 1, the oil supply device 40 includes an oil pan 41, an oil strainer 42, a pump 43 driven by the power of the crankshaft, an oil passage 44 such as a main oil gallery, and an oil passage. It is configured to include an oil injection nozzle 45 provided in the engine so as to receive oil supplied from the section 44 and inject oil, and an oil filter (not shown) that discharges oil from the pump 43 and filters the oil. The oil supply device 40 injects oil from the oil injection nozzle 45 toward the high-pressure fuel pump 7 to lubricate and cool each component of the high-pressure fuel pump 7, and supplies oil to each lubricating portion in the engine. It is configured to lubricate and cool the lubricating element.

In the high-pressure fuel pump 7, the pressure (MPa) of the fuel supplied from the fuel tank 6 to the pump body 31 is increased to an appropriate pressure between about 4 MPa and about 13 MPa, for example, and then the high-pressure fuel pipe 14. The high pressure fuel is discharged.
As described above, the high-pressure fuel is supplied from the fuel injection valve 8 to the internal combustion engine, that is, the combustion chamber defined by the cylinder block, the cylinder head, and the piston constituting the engine.

  The pump body 31 includes a pump body 51, a plunger 52 that reciprocates within the pump body 51, a roller lifter 53 that reciprocates the plunger 52, a lifter housing 54 that guides the roller lifter 53, a spring 55, and a seal unit 56. A holder 57 that holds the pump body 51 and is fixed to the lifter housing 54, a plate 58 that is attached to the plunger 52 and holds one end of the spring 55, and a seal member 59 such as an O-ring.

  The pump body 51 accommodates a through hole 61 formed in a columnar shape and penetrating in the axial direction, a pressure chamber 62 formed so that a part of the through hole 61 has a diameter increased, and a part of the electromagnetic spill valve 33. A housing hole 63 and a housing hole 64 for housing a part of the discharge valve case 35 are provided. A plunger 52 is inserted into the through hole 61, and the plunger 52 reciprocates in the through hole 61.

The pump body 51 is formed with a fuel discharge passage 65 that communicates the pressure chamber 62 and the accommodation hole 64 and discharges the fuel in the pressure chamber 62 into the discharge valve case 35.
Further, a cylindrical portion 66 is formed in the lower portion of the pump body 51, and a spring holding hole 67 for holding the spring 55 is formed in the cylindrical portion 66. Further, a guide hole 68 for guiding the seal unit 56 is formed inside the spring holding hole 67 in the radial direction, and the seal unit 56 slides in the guide hole 68.
An annular groove 69 is formed on the outer side of the cylindrical portion 66 in the radial direction, and a seal member 59 is attached to the annular groove 69.

  The plunger 52 is formed in a cylindrical shape, and as shown in FIGS. 2 and 3, a groove 52a is formed at one end, and the plate 58 is engaged with the inner wall surface of the plunger 52 surrounding the groove 52a. It has become. The other end of the plunger 52 is disposed so as to be exposed in the pressure chamber 62, and the fuel in the pressure chamber 62 is pressurized by entering the pressure chamber 62.

  The roller lifter 53 includes a lifter main body 71, a shaft 72, and a roller 73, as shown in FIGS.

  In the roller lifter 53, as shown in FIGS. 2 and 7, the roller lifter 53 is supported by the lifter housing 54 so that the same axis line of the roller lifter 53 as the axis line La of the lifter housing 54 passes through the axis Pc of the drive cam 32. ing.

The lifter main body 71 is formed in a columnar shape, and is guided to the lifter housing 54 by the side wall surface portion 71 a so as to reciprocate within the lifter housing 54.
3 and 5, the lifter body 71 has a side wall portion that supports one end of the shaft 72 so that the axis Lb of the shaft 72 is arranged substantially parallel to the axis Lc of the drive cam 32. 74 and a side wall 75 that supports the other end of the shaft 72.

  Further, as shown in FIGS. 5 to 7, the side wall surface portion 71 a of the lifter main body 71 is formed with a rotation preventing portion 71 b protruding from the side wall surface portion 71 a toward the outside in the radial direction. When reciprocating in the housing 54, it is prevented from rotating.

  As shown in FIGS. 7 and 8, the lifter main body 71 is formed with a plate accommodation hole 76 for accommodating the plate 58 at one end portion in the axial direction thereof. The plunger 52 engaged with the plate 58 and the spring 55 supported by the plate 58 are accommodated. Further, the lifter body 71 is formed with a roller accommodation hole 77 for accommodating the roller 73 at the other end in the axial direction, and the roller 73 supported by the shaft 72 is accommodated in the roller accommodation hole 77. It has become.

The shaft 72 is supported by the side wall 74 of the lifter main body 71 at one end in the axial direction thereof, and supported by the side wall 75 of the lifter main body 71 at the other end. As shown in FIG. 5, the end surfaces, the surface of the side wall 74 and the surface of the side wall 75 are flat so as not to protrude outward in the axial direction from the side wall 74 and the side wall 75, respectively.
Further, the shaft center Ps of the shaft 72 is disposed so as to be positioned on the axis line La of the lifter housing 54.

  The roller 73 is formed in a cylindrical shape and includes an outer ring 78 that is in sliding contact with the drive cam 32 at an outer peripheral surface portion 78a, and a plurality of needle bearings 79 that are rotatably interposed between the outer ring 78 and the shaft 72. Has been. Each needle bearing 79 has a high rigidity and a high radial load capacity, and the roller 73 is configured to rotate smoothly on the shaft 72. Further, the roller 73 and the drive cam 32 are arranged so that the axis of the roller 73 coincides with the axis Lb of the shaft 72 and the axis Lc of the drive cam 32, and the outer peripheral surface 78 a of the outer ring 78 contacts the drive cam 32 uniformly. The roller 73 is in sliding contact with the drive cam 32 in a so-called line contact state.

  As shown in FIGS. 2, 3, 9, and 10, the lifter housing 54 is formed in a cylindrical shape, and a cylindrical portion 54 a and a flange formed flat on the end portion of the cylindrical portion 54 a without any unevenness. Part 54b. A pump body accommodation hole 54c is formed at the end of the cylindrical portion 54a on the flange portion 54b side so that the lower end portion of the pump body 51 is accommodated. .

The cylindrical portion 54a is formed with a roller lifter accommodation hole 54d at the end opposite to the flange portion 54b, and the roller lifter 53 is slidably accommodated therein. In addition, an inclined portion 54e that is inclined with respect to the axis is formed at the end of the cylindrical portion 54a opposite to the flange portion 54b, and the engine components and drive cams arranged around the lifter housing 54 are formed. 32 is not interfered with.
The flange portion 54b is fixed to the pump mounting portion 18 of the engine by a fastener (not shown), and the holder 57 is fixed to the flange portion 54b by a fastener (not shown).

9 and 10, a through hole 54f having a predetermined width W in the circumferential direction and a predetermined length L in the axial direction is driven more than the seal member 59 in the cylindrical portion 54a. It is formed so as to be located on the cam 32 side, and a detent 71b formed on the side wall surface 71a of the lifter main body 71 is inserted into the through hole 54f.
The end of the through hole 54f on the pump body accommodation hole 54c side communicates with the pump body accommodation hole 54c, and when the roller lifter 53 is accommodated in the roller lifter accommodation hole 54d, the rotation preventing portion 71b of the lifter main body 71 penetrates. It can be inserted into the hole 54f.
The predetermined width W and the predetermined length L are appropriately selected based on setting parameters such as the structure, shape, and size of the high-pressure fuel pump 7.

  The pump body accommodation hole 54c is formed in communication with the roller lifter accommodation hole 54d so that the diameter thereof is larger than that of the roller lifter accommodation hole 54d, and the lifter body 71 is connected to the roller lifter accommodation hole 54c from the pump body accommodation hole 54c side. When inserted into 54d, the rotation preventing portion 71b of the lifter body 71 is configured to be easily inserted into the through hole 54f.

  The spring 55 is formed of a compression coil spring, one end is supported by the plate 58 of the lifter body 71, and the other end is supported by the pump body 51, and the roller lifter 53 is moved in the direction of the drive cam 32 via the plate 58. It comes to press.

  As shown in FIG. 3, the seal unit 56 includes a cylindrical portion 56a supported by the pump body 51, a seal portion 56b supported by an end portion of the cylindrical portion 56a and slidably surrounding the plunger 52, and a seal portion. And a coil spring 56c interposed so as to press 56b in the direction of the plunger 52. The seal unit 56 is configured to prevent the fuel that has passed through the gap between the pump body 51 and the plunger 52 from leaking into the lifter housing 54.

  As shown in FIG. 2, the holder 57 has an engaging portion 57a and a fixing portion 57b. The holder 57 is engaged with the pump body 51 by the engaging portion 57a, and the flange of the lifter housing 54 is fixed by the fixing portion 57b. It is fixed to the portion 54b.

  The plate 58 is formed in a disc shape, and has an annular convex portion 58a so as to support the end portion of the spring 55, as shown in FIGS. A through hole 58b is formed at the center of the annular protrusion 58a, and a notch (not shown) communicating with the through hole 58b is formed. One end of the plunger 52 in which a groove 52a is formed in the notch. The one end is engaged with the periphery of the through hole 58b.

  As shown in FIGS. 2 and 3, the drive cam 32 includes a substantially equilateral triangular cam 32a that is in sliding contact with the outer peripheral surface portion 78a of the outer ring 78 of the roller 73, and a shaft 32b that rotates the cam 32a. . As described above, the shaft 32b is arranged so that its axis Lc is substantially parallel to the axis of the roller 73 that coincides with the axis Lb of the shaft 72, and the outer peripheral surface 78a of the outer ring 78 of the roller 73 and the cam 32a. The pump main body 31 is attached to the pump mounting portion 18 of the engine so that is in a uniform line contact.

  The drive cam 32 only needs to reciprocate the roller 73 by its rotational movement, and may be formed in a shape other than a substantially equilateral triangle shape. For example, one portion of the outer peripheral surface portion of the drive cam may be formed to protrude outward in the radial direction, and two portions of the outer peripheral surface portion may be formed to protrude outward in the radial direction. It may be a thing, and it may be formed so that several places of an outer peripheral surface part may protrude toward the outer side of radial direction, and may protrude in a respectively different shape.

  The shaft 32b may be a shaft that is rotated by a drive source. For example, the shaft 32b may be an intake camshaft or an exhaust camshaft, and may be connected to a crankshaft of an engine by a power transmission member such as a chain. It may be another shaft that is connected and rotated by the power of the crankshaft. The drive source may be an electric motor such as a motor.

  2, the electromagnetic spill valve 33 includes an electromagnetic solenoid 81, a bobbin 82, a core 83, an armature 84, a poppet valve 85, a seat body 86, a coil spring 87, a terminal portion 88, and a support ring 89. ing. The pressure chamber 62 pressurizes fuel by the lower portion of the poppet valve 85, the lower portion of the seat body 86, the end of the plunger 52 exposed in the pressure chamber 62 of the pump body 51, and the inner wall portion of the pump body 51. Is defined.

The electromagnetic solenoid 81 is composed of a coil wound around the bobbin 82 in a ring shape, and the core 83 is inserted and fixed through a through-hole formed in the bobbin 82.
The armature 84 is supported by a support ring 89 while being fixed to one end of the poppet valve 85, and a part of the armature 84 can move in the bobbin 82 coaxially with the core 83.

Concave portions are respectively formed on the opposing surfaces of the core 83 and the armature 84, and a coil spring 87 is accommodated in a compressed state between the concave portions. The coil spring 87 urges the armature 84 toward the pressure chamber 62 side.
The poppet valve 85 is slidably accommodated in a through hole in the seat body 86, and a disc-shaped valve body 85a is formed at the lower end portion thereof. When the electromagnetic solenoid 81 is not energized, the urging force of the coil spring 87 separates the valve body 85a from the seat portion 86a of the seat body 86, and the electromagnetic spill valve 33 is in an open state.

  On the other hand, when the electromagnetic solenoid 81 is energized from the ECU 9 shown in FIG. 1 via the terminal portion 88, a magnetic circuit is formed by the support ring 89 that supports the core 83, the armature 84, and the electromagnetic spill valve 33 as a whole. The armature 84 moves to the core 83 side against the urging force. As a result, the poppet valve 85 moves to the side opposite to the pressure chamber 62, the valve body 85 a is seated on the seat portion 86 a of the seat body 86, and the electromagnetic spill valve 33 is closed.

  A plurality of fuel supply passages 86 b are formed in the seat body 86, and fuel can flow between each fuel supply passage 86 b and the pressure chamber 62 when the electromagnetic spill valve 33 is in the open state. ing.

  On the other hand, when the plunger 52 descends while the electromagnetic spill valve 33 is open, the low pressure fuel pumped from the fuel tank 6 by the operation of the feed pump 23 in the fuel tank 6 is filtered, the pressure regulator 22, the low pressure fuel. It flows through the pipe 11 and is sucked into the pressure chamber 62.

  The plunger 52 enters the pressure chamber 62 before the closing timing of the electromagnetic spill valve 33, and the plunger 52 reaches the top dead center after the electromagnetic spill valve 33 is closed. In addition, a gap is formed between the inner peripheral surface of the pressure chamber 62 and the outer peripheral surface of the plunger 52 in a state where the distal end portion of the plunger 52 has entered the pressure chamber 62.

  The intake valve case 34 is disposed between the electromagnetic spill valve 33 and the pump body 51, and circulates the fuel supplied from the low pressure fuel pipe 11, and has a fuel passage 34 a communicating with the fuel supply passage 86 b of the electromagnetic spill valve 33. doing.

  The discharge valve case 35 has a fuel passage 35a communicating with the fuel discharge passage 65 therein, and houses a check valve 36 in the fuel passage 35a. The discharge valve case 35 is connected to the high-pressure fuel pipe 14 so that the fuel discharged from the fuel discharge passage 65 flows through the fuel passage 35a and then flows through the check valve 36 to the high-pressure fuel pipe 14. It has become.

  The check valve 36 includes a seat body 91 and a spring base body 92 disposed in the suction valve case 34, a valve body 93 opposed to the seat body 91 so as to be able to contact and separate, and the valve body 93 against the seat body 91. And a coil spring 94 that urges toward the contact position.

  When the pressure of the fuel pumped into the check valve 36 exceeds a predetermined value (MPa), the valve body 93 is separated from the seat body 91 against the urging force of the coil spring 94 and is opened. The fuel discharged from the discharge passage 65 is supplied to the delivery pipe 13 through the high-pressure fuel pipe 14. The check valve 36 prevents the fuel discharged from the pressure chamber 62 from flowing back into the pressure chamber 62.

  As shown in FIG. 1, the fuel injection valve 8 includes, for example, a fuel injector for in-cylinder injection, and is provided in each of four cylinders. The fuel injection valve 8 has a plurality of slit-shaped injection holes at the tip, and the high-pressure fuel supplied from the delivery pipe 13 is highly atomized by an instruction from the ECU 9 and injected into a combustion chamber of an engine (not shown). It is supposed to be.

  The ECU 9 includes a CPU (Central Processing Unit), a ROM (Read Only Memory) that stores processing programs, a RAM (Random Access Memory) that temporarily stores data, and an electrically rewritable nonvolatile memory. It comprises an EEPROM (Electrically Erasable and Programmable Read Only Memory), an input interface circuit including an A / D converter and a buffer, an output interface circuit including a drive circuit, and a fuel injection control unit. .

  This fuel injection control unit constantly monitors the driving state of the fuel injection valve 8 for in-cylinder injection, and drives the fuel injection valve 8 and the electromagnetic spill valve 33 at high speed when necessary.

  A plurality of sensors such as the fuel pressure sensor 16 are connected to the input interface circuit of the ECU 9, and information output from these sensors is taken into the ECU 9 via the input interface circuit.

  The output interface circuit of the ECU 9 is connected to the feed pump 23 in the fuel tank 6, the fuel injection valve 8, the electromagnetic solenoid 81 in the high-pressure fuel pump 7, and the like, and is controlled via the output interface circuit. It has become.

  Next, a method for assembling the high-pressure fuel pump 7 according to the embodiment will be described.

  The method of assembling the high-pressure fuel pump 7 includes, for example, a preparation step in which the components of the high-pressure fuel pump 7 are aligned and an assembly tool including an assembly jig is prepared, and a roller lifter assembly step in which the roller lifter 53 is accommodated in the lifter housing 54 It is comprised including.

In the roller lifter assembling step, as shown in FIG. 11A, first, when the roller lifter 53 is accommodated in the roller lifter accommodating hole 54d of the lifter housing 54, the rotation preventing portion 71b of the roller lifter 53 is directed toward the pump body accommodating hole 54c. .
Next, the roller lifter 53 is inclined at an angle θ formed by the axis Lr of the roller lifter 53 with respect to the axis Lp of the pump body accommodation hole 54c.
Next, as shown in FIG. 11 (b), with the roller lifter 53 tilted, the roller lifter 53 is inserted into the pump body accommodation hole 54 c in the direction of the arrow, and the rotation stopper 71 b of the roller lifter 53 is inserted into the through hole of the lifter housing 54. 54f is inserted.
Next, the roller lifter 53 is inserted into the roller lifter receiving hole 54d so that the roller lifter 53 is substantially vertical so that the axis Lr of the roller lifter 53 substantially coincides with the axis Lp of the pump body receiving hole 54c.

As described above, when the roller lifter 53 is accommodated in the roller lifter accommodating hole 54d of the lifter housing 54, the roller lifter 53 is pumped in a state where the axis Lr of the roller lifter 53 is inclined at an angle θ formed with respect to the axis Lp of the pump body accommodating hole 54c. Since it is inserted into the body accommodating hole 54c, the assembly work of the high-pressure fuel pump is remarkably simplified, and the production efficiency of the high-pressure fuel pump is increased.
When the diameter of the pump body accommodation hole 54c is sufficiently larger than the diameter of the roller lifter 53 and the protrusion height of the rotation stopper 71b, when the roller lifter 53 is accommodated in the roller lifter accommodation hole 54d of the lifter housing 54, The roller lifter 53 may not be inclined at the angle θ formed by the axis Lr with respect to the axis Lp of the pump body accommodation hole 54c.

  Next, the operation of the high pressure fuel pump 7 according to the embodiment will be described.

  When it is necessary to inject fuel from the fuel injection valve 8 at a high pressure, for example, at the time of warming-up operation when the vehicle is accelerated or started, the electromagnetic spill valve 33 is first opened according to a command from the ECU 9, and the high-pressure fuel pump 7 inhalation stroke starts.

  At this time, the fuel flows from the feed pump 23 of the fuel tank 6 shown in FIG. 1 through the filter 24, the pressure regulator 22 and the pulsation damper 12 into the fuel passage 34a shown in FIG.

  When the shaft 32b rotates, for example, clockwise by the rotation of an engine (not shown), the cam 32a rotates in the same manner, the roller 73 rotates counterclockwise, and the roller lifter 53 is pressed by the pressure of the spring 55. The plunger 52 moves downward in the same direction, the roller lifter 53 descends, and the plunger 52 is positioned at the bottom dead center as shown in FIG. At this time, oil is injected from the oil injection nozzle 45, and the pump body 31 is lubricated by the injected oil. Further, when the roller lifter 53 descends, as shown in FIG. 7, the electromagnetic spill valve 33 is in an open state, so that fuel is sucked into the pressure chamber 62 from the fuel passage 34a.

  When the roller lifter 53 reaches the bottom dead center and the intake of fuel is completed, the electromagnetic spill valve 33 is closed by a command from the ECU 9, the pressure chamber 62 and the fuel passage 34a are shut off, and the pressurization stroke is started. In this pressurization stroke, the plunger 52 is raised, the fuel in the pressure chamber 62 is compressed, and the fuel pressure is increased to about 13 MPa, for example.

  When the fuel pressure in the pressure chamber 62 reaches about 13 MPa, as shown in FIG. 13, the check valve 36 is opened by the fuel pressure, and the high-pressure fuel in the pressure chamber 62 is delivered via the high-pressure fuel pipe 14. It is supplied to the pipe 13.

  At this time, an injection command is transmitted from the injection control unit of the ECU 9 to the fuel injection valve 8, and high-pressure fuel is transmitted from the fuel injection valve 8 to the internal combustion engine, that is, the combustion chamber defined by the cylinder block, cylinder head, and piston constituting the engine. Be injected. In this case, for each cylinder of the engine (not shown), the fuel injection such as the injection amount and the injection timing is controlled by the ECU 9 according to the combustion cycle of each cylinder.

  Thus, since the high-pressure fuel pump 7 according to the embodiment is configured, the following effects can be obtained.

  That is, the high-pressure fuel pump 7 according to the embodiment includes a roller 73 that is in sliding contact with the drive cam 32, a roller lifter 53, a lifter housing 54, a pump body 51, a spring 55, and a plunger 52. The cylindrical portion 54a having the roller lifter accommodation hole 54d and the pump body accommodation hole 54c, and the flange portion 54b. The wall surface of the roller lifter accommodation hole 54d has a predetermined length L and a predetermined width W. Is formed so as to be positioned closer to the drive cam 32 than the seal member 59, and the rotation preventing portion 71b of the roller lifter 53 is slidably inserted into the through hole 54f, and an annular groove 69 is formed in the outer peripheral surface portion of the pump body 51. The sealing member 59 is mounted in the annular groove 69.

  As a result, the annular groove 69 is formed in the outer peripheral surface portion of the pump body 51, and the seal portion is configured by a so-called shaft seal structure in which the seal member 59 is mounted in the annular groove 69. The effect of being simple is obtained. Since the seal member 59 can be configured by a highly versatile O-ring, the assembling workability and the component management are improved and the production efficiency is improved.

  Also, a through hole 54f is formed in the wall surface of the roller lifter receiving hole 54d so as to be positioned closer to the drive cam 32 than the seal member 59, and the rotation stopper 71b of the roller lifter 53 is slidably inserted into the through hole 54f. Therefore, unlike the conventional high-pressure fuel pump, the through hole for rotation prevention is not formed through the flange portion of the lifter housing, and it is not necessary to use a specially shaped seal member. Further, since the rotation preventing portion 71b is inserted into the through hole 54f, an effect that the relative rotation of the roller lifter 53 is reliably prevented with a simple structure can be obtained.

  Further, an appropriate clearance can be maintained between the roller lifter 53 and the lifter housing 54, and a uniform and appropriate contact between the roller 73 and the drive cam 32 can be maintained. It is suppressed and the effect that durability improves is acquired.

  In the high-pressure fuel pump 7 according to the embodiment, the case where the annular groove 69 is formed in the outer peripheral surface portion of the pump body 51 and the seal member 59 is attached to the annular groove 69 has been described. However, in the high-pressure fuel pump according to the present invention, an annular groove may be formed in a portion other than the outer peripheral surface portion of the pump body, and a seal member may be attached to the annular groove.

  For example, as in the high pressure fuel pump 7a according to the first modification shown in FIG. 14, an annular groove 69 is formed on the inner wall surface portion of the lifter housing 54 surrounding the pump body accommodation hole 54c formed in the cylindrical portion 54a of the lifter housing 54. The sealing member 59 may be attached to the annular groove 69.

  In this case, since the seal portion is constituted by a so-called shaft seal structure, an effect that the structure of the seal portion is remarkably simplified can be obtained as in the embodiment. Since the seal member 59 can be formed of a highly versatile O-ring, as in the embodiment, the assembling workability and the parts management are improved and the production efficiency is improved.

  Further, as in the high pressure fuel pump 7b according to the second modification shown in FIG. 15, an annular groove 69 is formed at the abutting portion that abuts the flange portion 54b of the lifter housing 54 at the lower end of the pump body 51, and this annular groove A seal member 59 may be attached to 69.

  In this case, since the flange portion 54b of the lifter housing 54 is formed flat without any irregularities such as grooves, and the seal portion is configured with a simple seal structure, the structure of the seal portion is remarkably simple as in the embodiment. The effect of becoming. Since the seal member 59 can be formed of a highly versatile O-ring, as in the embodiment, the assembling workability and the parts management are improved and the production efficiency is improved.

  Further, like the high-pressure fuel pump 7c according to the third modification shown in FIG. 16, an annular groove 69 is formed on the upper surface portion of the flange portion 54b of the lifter housing 54, and the seal member 59 is attached to the annular groove 69. It may be.

  In this case, since the flange portion 54b is formed flat without grooves and other irregularities, the seal portion is configured with a simple seal structure, so that the structure of the seal portion is remarkably simplified as in the embodiment. An effect is obtained. Since the seal member 59 can be formed of a highly versatile O-ring, as in the embodiment, the assembling workability and the parts management are improved and the production efficiency is improved.

  As described above, according to the present invention, it is possible to provide a high-pressure fuel pump that can reduce the number of parts with a simple structure, can be configured with a versatile seal member, and has high production efficiency. The pump is effective for all pumps having a mechanism for converting the rotational motion of the drive cam into the reciprocating motion of the plunger.

DESCRIPTION OF SYMBOLS 5 Fuel supply apparatus 7 High pressure fuel pump 31 Pump main body 32 Drive cam 40 Oil supply apparatus 51 Pump body 52 Plunger 53 Roller lifter 54 Lifter housing 54a Cylindrical part 54b Flange part 54c Pump body accommodation hole 54d Roller lifter accommodation hole 54f Through hole 59 Seal member 66 Cylindrical portion 69 Annular groove 71 Lifter body 71a Side wall surface portion 71b Non-rotating portion 72 Shaft 73 Roller

Claims (3)

A roller in sliding contact with the drive cam, a roller lifter for rotatably supporting the roller, a lifter housing for slidably supporting the roller lifter, a pump body supported by the lifter housing, and the roller lifter for the drive cam. A spring that presses in a direction and a plunger that is slidably supported by the pump body and that defines a pressure chamber together with the pump body, and the plunger reciprocates according to the rotational movement of the drive cam. In the high pressure fuel pump that discharges by increasing the pressure of the fuel sucked into the pressure chamber,
A through hole is formed in the lifter housing to slidably receive the rotation preventing portion protruding from the outer peripheral surface of the roller lifter in the axial direction of the plunger.
The lifter housing has an inner peripheral surface portion, the pump body has an outer peripheral surface portion in contact with the inner peripheral surface portion, an annular groove is formed in either the inner peripheral surface portion or the outer peripheral surface portion, and the annular groove An annular seal member is attached to
The through hole is formed closer to the drive cam than the seal member ;
The lifter housing has a roller lifter accommodation hole that accommodates the roller lifter, and a pump body accommodation hole that accommodates the pump body and has a diameter larger than the roller lifter accommodation hole and communicates with the roller lifter accommodation hole, An end portion of the through hole on the pump body side communicates with the pump body accommodation hole . A roller in sliding contact with the drive cam, a roller lifter for rotatably supporting the roller, a lifter housing for slidably supporting the roller lifter, a pump body supported by the lifter housing, and the roller lifter for the drive cam. A spring that presses in a direction and a plunger that is slidably supported by the pump body and that defines a pressure chamber together with the pump body, and the plunger reciprocates according to the rotational movement of the drive cam. In the high pressure fuel pump that discharges by increasing the pressure of the fuel sucked into the pressure chamber,
A through hole is formed in the lifter housing to slidably receive the rotation preventing portion protruding from the outer peripheral surface of the roller lifter in the axial direction of the plunger.
The lifter housing has a flat portion, the pump body has a contact portion in contact with the flat portion, and an annular groove is formed in one of the contact portion and the flat portion. An annular seal member is attached,
The through hole is formed closer to the drive cam than the seal member ;
The lifter housing has a roller lifter accommodation hole that accommodates the roller lifter, and a pump body accommodation hole that accommodates the pump body and has a diameter larger than the roller lifter accommodation hole and communicates with the roller lifter accommodation hole, An end portion of the through hole on the pump body side communicates with the pump body accommodation hole .   The high-pressure fuel pump according to claim 1, wherein the annular seal member is an O-ring.

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