JP2012122401A - Fuel pumping system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel pumping system which enables assembling and mounting works of a fuel pump to be easily performed as well as allowing a mounting structure of the fuel pump to be simple and the number of part items to be reduced.SOLUTION: The fuel pump 13 is supported, via a seal member 15, to a cylinder head cover 14 fixed to a cylinder head 11. The fuel pump 13 is provided with a plunger 20 engaging with a cam 17 by means of energizing force of a spring 21. Fuel is subjected to pressure feed from the fuel pump 13 by a reciprocating motion of the plunger 20 resulting from a rotary motion of the cam 17. Between the case 13a of the fuel pump 13 and the cylinder head cover 14, there is provided a locking mechanism 22 for locking and holding the fuel pump 13 to a supporting position, utilizing the energizing force of the spring 21.

Description

  The present invention relates to a fuel pump device that pressurizes fuel using the rotational force of a camshaft in an engine and supplies the pressurized fuel to a fuel accumulator system of the engine.

  Conventionally, as this type of fuel pump device, configurations such as Patent Document 1 and Patent Document 2 have been proposed. In this conventional configuration, the fuel pump is fixed to the cylinder head cover fixed on the cylinder head of the engine by a plurality of bolts. The plunger provided in the fuel pump is pressed against the cam on the cam shaft provided in the cylinder head by the urging force of the spring, and the fuel is discharged from the fuel pump by the reciprocation of the plunger accompanying the rotation of the cam. It is pumped to the engine's fuel pressure system.

JP 2010-121576 A JP 2010-138729

  As described above, in the conventional fuel pump device, the fuel pump is fixed to the cylinder head cover with the plurality of bolts. For this reason, the mounting structure of the fuel pump with respect to the support member is complicated, the number of parts is increased, and the assembly work of the fuel pump is complicated.

  The present invention has been made paying attention to such problems existing in the prior art. An object of the present invention is to provide a fuel pump device that has a simple structure for mounting a fuel pump, can reduce the number of parts, and can easily perform a mounting operation of the fuel pump.

  In order to achieve the above object, the present invention supports a fuel pump via a seal member on a support member fixed to a cylinder head, and the fuel pump includes a plunger that engages with a cam by a biasing force of a spring. In the fuel pump device in which the fuel is pumped by the reciprocating motion of the plunger accompanying the rotation of the cam, the fuel pump is utilized between the case of the fuel pump and the support member using the biasing force of the spring. It is characterized in that a locking means is provided for locking and holding at the support position.

  Therefore, in the fuel pump device of the present invention, the plunger provided in the fuel pump is pressed against the cam in the cylinder head by the biasing force of the spring while the fuel pump is supported on the support member. At the same time, the fuel pump is locked and held at the support position on the support member by using the biasing force of the spring by the locking means. Therefore, unlike the conventional configuration, a plurality of bolts and the like for fixing the fuel pump to the support position on the support member are not required, the fuel pump mounting structure to the support member is simple, and the number of parts is reduced. be able to. Further, since it is not necessary to perform troublesome work such as bolt tightening, the assembly work of the fuel pump to the support member can be easily performed.

The said structure WHEREIN: The said supporting member is good to comprise with a cylinder head cover.
The said structure WHEREIN: The said supporting member is good to comprise with the support metal fitting fixed to the cylinder head.

  In the above-mentioned configuration, the locking means is formed on the other side so as to be able to engage with the locking projection formed on either the fuel pump case or the support member. It is good to comprise by the latching recessed part made and the guide path formed continuously from the latching recessed part so that the said latching convex part may be guided to the position engaged with a latching recessed part.

  As described above, according to the present invention, the fuel pump mounting structure is simple, the number of parts can be reduced, and the fuel pump can be easily assembled.

The principal part sectional view showing the fuel pump device of a 1st embodiment. The partial expanded sectional view of the support cylinder part of the cylinder head cover in the 2-2 line of FIG. Sectional drawing in the 3-3 line of FIG. Sectional drawing of the case of the fuel pump in the position corresponding to FIG. The fragmentary sectional view of the support cylinder part of the cylinder head cover in the fuel pump of 2nd Embodiment. Sectional drawing in the 6-6 line of FIG. The partial front view which shows the case of the fuel pump supported by the support cylinder part of the cylinder head cover of FIG. Sectional drawing in the 8-8 line of FIG. The principal part sectional view showing the fuel pump device of a 3rd embodiment.

(First embodiment)
A fuel pump device according to a first embodiment of the present invention will be described below with reference to FIGS.

  As shown in FIG. 1, in the fuel pump device of this embodiment, a cylinder head cover 14 is fixed on a cylinder head 11 of the engine. The cylinder head cover 14 is formed of a metal material such as iron or an aluminum alloy, and constitutes a support member for supporting the fuel pump 13. On the inner side of the top wall of the cylinder head cover 14, a support cylinder portion 14a is formed to protrude. The fuel pump 13 is supported on the cylinder head cover 14 by inserting the lower end portion of the cylindrical case 13 a of the fuel pump 13 into the support cylinder portion 14 a of the cylinder head cover 14. An annular sealing material 15 is provided on the outer peripheral surface of the case 13a to be joined to the opening side end portion of the inner surface of the support cylinder portion 14a.

  A cam shaft 16 is rotatably supported in the cylinder head 11, and a cam 17 is fixed to the outer periphery of the cam shaft 16. A holder 18 is provided at a position on the cam 17 side of the case 13 a of the fuel pump 13 so as to be movable in the vertical direction in FIG. 1, and a roller 19 as a cam follower engaged with the cam 17 is rotatably supported on the holder 18. Has been. A plunger 20 that engages with the cam 17 via a holder 18 and a roller 19 is disposed in the case 13a of the fuel pump 13 so as to be movable in the axial direction. A spring 21 is interposed between the plunger 20 and the case 13 a to urge the plunger 20 toward the cam 17 and press the roller 19 against the cam 17. When the cam 17 is rotated, the plunger 20 is reciprocated via the roller 19 and the holder 18, and the fuel is pressurized by the fuel pump 13 and supplied to the pressure accumulation system of the engine.

  As shown in FIGS. 2 to 4, between the case 13 a of the fuel pump 13 and the support cylinder portion 14 a of the cylinder head cover 14, the fuel pump 13 is placed on the cylinder head cover 14 using the biasing force of the spring 21. A locking mechanism 22 is provided as a locking means for locking and holding at the support position. The locking mechanism 22 includes a pair of locking projections 23 formed 180 degrees apart on the outer peripheral surface of the lower end of the case 13a of the fuel pump 13, and a cylinder so as to be able to engage with the locking projections 23. A pair of locking recesses 24 formed on the inner peripheral surface of the support cylinder portion 14a of the head cover 14 and the locking recesses 24 are continuous with the locking recesses 24 so as to guide the locking projections 23 to positions where they engage with the locking recesses 24. And a pair of groove-shaped guide paths 25 formed on the inner peripheral surface of the support cylinder portion 14a. Each guide path 25 is formed between the upper and lower ends of the inner peripheral surface of the support cylinder portion 14 a and extends in the axial direction of the plunger 20, and the first guide portion 25 a and the locking recess 24. A second guide portion 25b formed between the lower end portions and extending in the circumferential direction is provided.

  Next, an assembling method when the fuel pump 13 is assembled on the cylinder head cover 14 including the cylinder head cover 14 in the fuel pump apparatus configured as described above will be described.

  When the fuel pump 13 is assembled, as shown in FIG. 2, the locking projection 23 on the case 13 a side of the fuel pump 13 is disposed corresponding to the upper end of the guide path 25 on the support cylinder portion 14 a side of the cylinder head cover 14. In this state, the case 13 a of the fuel pump 13 is inserted into the support cylinder portion 14 a of the cylinder head cover 14. Then, the latching convex part 23 enters the first guide part 25a of the guide path 25 and is moved to the lower end part of the first guide part 25a as shown by a chain line in FIG. At this time, as shown in FIG. 1, the plunger 20 on the fuel pump 13 side is pressed against the cam 17 side in the cylinder head 11 by the biasing force of the spring 21, and the roller 19 is pressed against the cam 17 via the holder 18. Is done.

  Thereafter, when the fuel pump 13 is rotated in one direction, the locking projection 23 is moved in the circumferential direction along the second guide portion 25b of the guide path 25, and is arranged corresponding to the lower end portion of the locking recess 24. Is done. In this state, when the assembly operation of the fuel pump 13 is released, the case 13a of the fuel pump 13 is slightly moved upward by the urging force of the spring 21, and the locking projection 23 is formed as shown by a chain line in FIG. Engaged with the locking recess 24. By this engagement, the case 13a of the fuel pump 13 is fixed and held at the fitting position of the cylinder head cover 14 with respect to the support cylinder portion 14a.

Therefore, according to this embodiment, the following effects can be obtained.
(1) In this fuel pump device, when the fuel pump 13 is supported on the cylinder head cover 14, the roller 19 provided in the fuel pump 13 is applied to the cam 17 in the cylinder head 11 by the biasing force of the spring 21. Press contact. At the same time, the fuel pump 13 is fixed at a predetermined position on the cylinder head cover 14 by using the biasing force of the spring 21 by the locking mechanism 22. Therefore, unlike the conventional configuration, a plurality of bolts and the like are not required. For this reason, the attachment structure of the fuel pump 13 to the cylinder head cover 14 is simple and the number of parts can be reduced. Further, since it is not necessary to perform troublesome operations such as bolting, the assembly operation of the fuel pump 13 to the cylinder head cover 14 can be easily performed.

  (2) In this fuel pump device, the cylinder head cover 14 is made of a metal material. For this reason, even if the biasing force of the spring 21 is strong, the fuel pump 13 can be directly mounted and supported on the cylinder head cover 14 made of a metal material.

  (3) In this fuel pump device, the locking mechanism 22 is provided on the locking protrusion 23 formed on the outer peripheral surface of the case 13 a of the fuel pump 13 and the inner peripheral surface of the support cylinder portion 14 a of the cylinder head cover 14. The locking recess 24 is formed, and the guide path 25 is formed on the inner peripheral surface of the support cylinder portion 14 a continuously to the locking recess 24. For this reason, a dedicated part is not required. Therefore, not only the structure of the locking mechanism 22 is simple, but also when the case 13a of the fuel pump 13 is assembled to the support cylinder portion 14a of the cylinder head cover 14, the locking projection 23 is moved from the guide path 25 to the locking recess 24. The fuel pump 13 can be easily assembled.

(Second Embodiment)
Next, a fuel pump device according to a second embodiment embodying the present invention will be described focusing on differences from the first embodiment.

  In the locking mechanism 22 of the second embodiment, as shown in FIGS. 5 to 8, contrary to the case of the first embodiment, the locking projection 23 is formed on the support cylinder portion 14 a of the cylinder head cover 14. The locking recess 24 and the guide path 25 are formed on the outer peripheral surface of the case 13 a of the fuel pump 13 while being formed on the inner peripheral surface.

  Therefore, according to the second embodiment, when the case 13 a of the fuel pump 13 is assembled to the support cylinder portion 14 a of the cylinder head cover 14, the first guide portion 25 a of the guide path 25 corresponds to the locking convex portion 23. In addition, the case 13a is inserted into the support cylinder portion 14a, and the fuel pump 13 may be rotated in one direction when the second guide portion 25b comes into contact with the locking projection 23. If it does in this way, with the urging | biasing force of the spring 21, the latching recessed part 24 will engage with the latching convex part 23, and the fuel pump 13 will be fixed.

Therefore, also in the second embodiment, the same effect as that of the first embodiment can be obtained.
(Third embodiment)
Next, a third embodiment of the fuel pump device embodying the present invention will be described focusing on differences from the first embodiment.

  In the third embodiment, as shown in FIG. 9, the cylinder head cover 14 is made of synthetic resin, and a hole 31 for inserting the fuel pump 13 is formed on the top wall. A support fitting 32 made of a metal material such as iron or aluminum alloy is fixed on the cylinder head 11 by a plurality of bolts 33 so as to correspond to the hole 31 of the cylinder head cover 14. A support member for supporting the fuel pump 13 is configured by the support fitting 32, and a support cylinder portion 14 a that is continuous with the hole 31 of the cylinder head cover 14 is formed on the support fitting 32. Further, as in the first embodiment, the engagement for holding the fuel pump 13 in the support position between the case 13a of the fuel pump 13 and the support cylinder portion 14a using the biasing force of the spring 21. A stop mechanism 22 is provided.

Therefore, according to the third embodiment, in addition to the effects described in (1) and (3) in the first embodiment, the following effects can be obtained.
(4) In this fuel pump device, the support member is constituted by a support fitting 32 fixed to the cylinder head 11. For this reason, even when the cylinder head cover 14 is formed of a synthetic resin, the fuel pump 13 can be firmly fixed on the support fitting 32 made of a metal material.

(Example of change)
In addition, this embodiment can also be changed and embodied as follows.
A reinforcing part such as a thick part is provided on the cylinder head cover 14 made of synthetic resin, and the fuel pump 13 is supported on the reinforcing part via the locking mechanism 22 similar to each of the above embodiments.

  In each of the above embodiments, the holder 18 and the roller 19 are omitted, and the cam 17 is directly engaged with the plunger 20.

  DESCRIPTION OF SYMBOLS 11 ... Cylinder head, 13 ... Fuel pump, 13a ... Case, 14 ... Cylinder head cover, 14a ... Supporting cylinder part, 15 ... Sealing material, 16 ... Cam shaft, 17 ... Cam, 20 ... Plunger, 21 ... Spring, 22 ... Engagement Locking mechanism as locking means, 23: locking projection, 24: locking recess, 25: guide path, 32: support fitting.

Claims (4)

A fuel pump is supported by a support member fixed to the cylinder head via a seal material. The fuel pump is provided with a plunger that engages with the cam by the biasing force of the spring, and the plunger reciprocates as the cam rotates. In a fuel pump device that pumps fuel,
A fuel pump device characterized in that a locking means for locking and holding the fuel pump at a support position using the biasing force of the spring is provided between the fuel pump case and the support member. The fuel pump device according to claim 1, wherein the support member includes a cylinder head cover. The fuel pump device according to claim 1, wherein the support member is constituted by a support fitting fixed to a cylinder head. The locking means includes a locking projection formed on one of the fuel pump case and the support member, and a locking recess formed on the other so as to be engageable with the locking projection. And a guide path formed continuously from the locking recess so as to guide the locking projection to a position engaging with the locking recess. The fuel pump device according to any one of the above.

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