JP2013155606A - Lubricating structure of lifter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubricating structure of a lifter in which lubricating oil can be supplied to a sliding area between a lifter guide and the lifter without trouble.SOLUTION: A cam 20 has a cam face 21 abutting a roller 43 of a lifter 40, and pushing the roller 43 by rotating due to the rotation of a camshaft 30 thereby causing the lifter 40 to move. Moreover, the cam 20 has a protruding part 10 having a shape to protrude in a radial direction of the camshaft 30, receiving lubricating oil supplied toward an edge face 22 intersecting the cam face 21, and splattering the lubricating oil toward a sliding face 52 side of the lifter guide in association with the rotation of the camshaft 30.

Description

  The present invention relates to a lifter lubrication structure for a fuel pump, for example.

  A conventional lifter lubrication structure is disclosed in Patent Document 1. This is arranged close to the lifter guide and lifter guide (housing) having a lifter for feeding fuel to the injector side, a lifter inserted into the lifter so as to be reciprocally movable, and perpendicular to the extending direction of the bore. A camshaft extending in the direction, and a cam supported by the camshaft and in contact with the lifter. The lifter is in contact with the lower end portion of the plunger, and the upper end portion of the plunger faces the pump chamber. The lifter and plunger are urged toward the cam by a coil spring.

  When the lifter is pushed up by the rotation of the cam, the plunger is also pushed up and the volume of the pump chamber is reduced. On the other hand, when the lifter and the plunger are pulled down by the biasing force of the coil spring by the further rotation of the cam, the volume of the pump chamber increases. Thus, the volume of the pump chamber is increased / decreased in this manner, so that the fuel is sucked / discharged.

JP 2009-26041 A

  In the above case, since the sliding area is between the lifter guide and the lifter and between the lifter and the cam, it is necessary to supply lubricating oil to this sliding area. When supplying lubricating oil to the sliding region, for example, an oil passage may be formed inside the lifter guide so that one end faces the inside of the bore. However, when the oil passage is formed inside the lifter guide, if it is cut, it takes time for the processing, and there is a situation that productivity is poor. Also, for example, when the cam is located below the lifter, the sliding area between the cam and the lifter can be lubricated by adopting a technique in which the lower end of the cam is immersed in the lubricating oil in the oil bath. It is difficult to lubricate the sliding area between the guide and lifter. For this reason, there is a demand for the construction of a route that can supply the lubricating oil to the sliding region between the lifter guide and the lifter without trouble.

  The present invention has been completed based on the above circumstances, and an object of the present invention is to provide a lifter lubrication structure that can supply lubricating oil to a sliding region between a lifter guide and a lifter without any trouble.

  As means for achieving the above object, the invention of claim 1 has a lifter and a bore into which the lifter is reciprocally inserted, and the lifter is slidable on an inner peripheral surface of the bore. A lifter guide having a sliding surface, a camshaft disposed in the vicinity of the lifter guide and extending in a direction perpendicular to the extending direction of the bore, supported by the camshaft, and rotated by the camshaft. A cam having a cam surface that pushes the lifter by rotating to perform a moving operation of the lifter, and protrudes in a radial direction of the camshaft from either the cam or the camshaft. The lubricating oil supplied to the end surface of the cam that intersects the cam surface is received, and the lubricating oil is splashed up to the sliding surface of the lifter guide as the cam shaft rotates. Characterized in place and a part.

  The invention of claim 2 is characterized in that, in the invention of claim 1, the protrusion is formed on the end face of the cam.

  The invention of claim 3 is characterized in that, in the invention of claim 2, a plurality of the protrusions are formed on the end surface of the cam at intervals in the circumferential direction.

  According to a fourth aspect of the present invention, the camshaft is supported between the upper journal and the lower journal according to any one of the first to third aspects, and both the upper journal and the lower journal are supported. An oil passage for supplying the lubricating oil to the end face side of the cam is formed in at least one of the overlapping surfaces.

<Invention of Claim 1>
When lubricating oil is supplied to the end face side of the cam, the supplied lubricating oil is received by the projecting portion protruding in the radial direction of the camshaft and jumps to the sliding face side of the lifter guide as the camshaft rotates. Then, the sliding area between the lifter guide and the lifter is lubricated. In this case, since the supply route of the lubricating oil is directed to the end surface side of the cam, variations in the supply route are expanded. Further, since it is not necessary to form an oil passage that faces the inside of the bore in the housing, productivity is improved. Therefore, there is provided a lifter lubrication structure capable of supplying lubricating oil to the sliding region between the lifter guide and the lifter without any trouble.

<Invention of Claim 2>
Since the protrusion is formed on the end face of the cam, the lubricating oil supplied to the end face of the cam can be efficiently received by the protrusion, and the waste of the lubricating oil can be reduced.

<Invention of Claim 3>
Since a plurality of protrusions are formed on the end face of the cam at intervals in the circumferential direction, waste of lubricating oil can be further reduced.

<Invention of Claim 4>
Since an oil passage for supplying lubricating oil to the end face side of the cam is formed on at least one of the overlapping surfaces of both the upper journal and the lower journal, the oil passage can be cast. Therefore, cutting is unnecessary, and the productivity is further improved accordingly.

It is a principal part enlarged view of the lifter lubrication structure which concerns on Embodiment 1 of this invention. It is an enlarged bottom view showing the state in which the oil path was formed in the overlapping surface of an upper journal. It is an expanded sectional view showing the state where the camshaft was supported between the upper journal and the lower journal and the oil passage was formed. It is a side view of a cam. It is a general view of a lifter lubrication structure.

<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS. The lifter lubrication structure according to the first embodiment exemplifies a lifter lubrication structure of a fuel pump of an automobile, and includes a cylinder 60, a housing 50 (lifter guide), a lifter 40, a camshaft 30, a cam 20, and a protrusion 10. It has.

  As shown in FIG. 5, the cylinder 60 is disposed above the housing 50, and a spring seat 70 is sandwiched between the cylinder 60 and the housing 50. The cylinder 60 is formed with a guide hole 61 extending in the axial direction (the reciprocating movement direction of the lifter 40 and the camshaft 30 and the vertical direction in the drawing). A pump chamber 62 is formed in the cylinder 60, and the upper end of the guide hole 61 communicates with the pump chamber 62. An upper portion of the plunger 80 is inserted into the guide hole 61 of the cylinder 60 so as to be able to reciprocate. The upper end of the plunger 80 is inserted into the pump chamber 62 so as to advance and retract.

  A bore 51 extending in the axial direction is formed in the housing 50, and a lower end portion of the housing 50 is fitted to an upper end portion of the bore 51. A lifter 40 is inserted into the bore 51 of the housing 50 so as to be able to reciprocate. A sliding surface 52 on which the lifter 40 can slide is formed on the inner peripheral surface of the bore 51. The sliding surface 52 is disposed substantially vertically along the axial direction.

  As shown in FIGS. 1 and 5, the lifter 40 is sandwiched between a bottomed cylindrical lifter body 41, a pair of opposing walls 42 projecting downward from the lower end of the lifter body 41, and the opposing walls 42. And a pin 44 that passes through both opposing walls 42 and rotatably supports the roller 43. The outer peripheral surface of the lifter body 41 is slidable on the sliding surface 52 of the bore 51.

  As shown in FIG. 5, the lower end portion of the plunger 80 is inserted into the lifter body 41, and the lower end of the plunger 80 is in contact with the inner upper surface of the lifter body 41. Further, a retainer 90 attached to the lower end portion of the plunger 80 is in contact with the inner upper surface of the lifter body 41. A coil spring 100 is inserted between the retainer 90 and the spring seat 70, and the lifter 40 and the plunger 80 are urged downward (on the cam 20 side) by the coil spring 100.

  As shown in FIG. 1, the camshaft 30 is in the shape of a rod extending elongated in a direction orthogonal to the axial direction of the bore 51. A pair of upper journals 53 are formed at the lower end of the housing 50 so as to face each other, and a pair of lower journals 54 abut against the upper journal 53 from below, and as shown in FIG. The camshaft 30 is rotatably supported in the space 55.

  An oil passage 57 is formed in the overlapping surface 56 of the upper journal 53 among the overlapping surfaces of the upper journal 53 and the lower journal 54. The oil passage 57 is for supplying lubricating oil to the sliding surface 52 of the bore 51, and is an oil passage (not shown) for supplying lubricating oil between the journals 53, 54 and the camshaft 30. Z)). Specifically, as shown in FIG. 2, the oil passage 57 has a bowl-like shape that is elongated in a direction intersecting the extending direction of the camshaft 30 and the axial direction of the bore 51 on the overlapping surface 56 of the upper journal 53. The first oil passage 58 and a hook-like second oil passage 59 extending in the extending direction of the camshaft 30 at the end of the first oil passage 58 are formed. That is, the second oil passage 59 is arranged in parallel with the camshaft 30. The start end of the first oil passage 58 is branched and connected to an oil supply passage (not shown) of the engine, and the end of the second oil passage 59 is opened at the side edge of the upper journal 53 and is opposed to the end face of the cam 20. Has been. Further, the oil passage 57 is disposed in a substantially line-symmetrical position across the cam 20 in each of the pair of upper journals 53.

  As shown in FIG. 1, the cam 20 is provided on the camshaft 30 and is disposed between the upper journals 53 and the lower journals 54 facing each other and below the rollers 43. The cam 20 has a circumferential cam surface 21 that abuts on the outer peripheral surface of the roller 43 and a pair of end surfaces 22 that intersect (specifically, orthogonally intersect) the cam surface 21. Both end surfaces 22 of the cam 20 are connected to both ends in the width direction of the cam surface 21 (extending direction of the camshaft 30), and are arranged along the radial direction of the camshaft 30.

  In the above-described lifter lubrication structure, when the camshaft 30 rotates, the roller 43 rotates on the cam surface 21 of the rotating cam 20, and the coil spring 100 repeatedly expands and contracts, and the lifter 40 moves in the bore 51 in the axial direction. Reciprocate. Then, the plunger 80 reciprocates in the guide hole 61 together with the lifter 40 in the axial direction, whereby the volume of the pump chamber 62 is increased / decreased, and fuel is sucked / discharged.

  Now, as shown in FIG. 4, the protrusion 10 is provided on both end faces 22 of the cam 20. Specifically, the protrusion 10 is configured to protrude in the extending direction of the camshaft 30 and the radial direction of the camshaft 30 at both end faces 22 of the cam 20 and is opposed to a position directly below the sliding surface 52 of the bore 51. In addition, the camshaft 30 is disposed in pairs at positions corresponding to both ends in the radial direction. More specifically, the protrusion 10 has a blade-like shape that gradually decreases in thickness from the camshaft 30 side toward the distal end side in the radial direction, and the camshaft 30 has a diameter on the front side in the rotational direction. It has the receiving surface 12 extended linearly along a direction. Further, the protrusion 10 can pass through a position facing the second oil passage 59 by the rotation of the cam 20 and can receive the lubricating oil injected from the second oil passage 59. The protrusion 10 is die-molded integrally with the cam 20 by being opened with a radial parting line P along the receiving surface 12 as a boundary.

Next, a method for lubricating the sliding region of the lifter lubrication structure according to the first embodiment will be described.
In the first embodiment, as shown in FIG. 2, the lubricating oil flows from the first oil passage 58 to the second oil passage 59 and is injected from the end of the second oil passage 59 toward the end surface 22 of the cam 20. . At this time, the cam 20 rotates around the axis of the camshaft 30. The injected lubricating oil is received by the receiving surface 12 of the projection 10 after contacting the end surface 22 of the cam 20 or directly received by the receiving surface 12 of the projection 10. Next, the lubricating oil is splashed upward from the receiving surface 12 of the protrusion 10 by the rotational force of the cam 20 and adheres to the sliding surface 52 of the bore 51 located above the lubricating oil. The lubricating oil adhering to the sliding surface 52 is spread over the entire sliding surface 52 by the reciprocating motion of the lifter 40 and lubricates the sliding region between the housing 50 and the lifter 40. In addition, a part of the lubricating oil drops and comes into contact with the cam surface 21 of the cam 20 to lubricate the sliding region between the cam 20 and the lifter 40.

  As described above, according to the first embodiment, the lubricating oil supplied to the end surface 22 side of the cam 20 is received by the protrusion 10 and moves to the sliding surface 52 side of the lifter guide as the camshaft 30 rotates. The sliding area between the lifter guide and the lifter 40 is lubricated on the sliding surface 52 side. In this case, since the oil passage 57 is directed to the end face 22 side of the cam 20, it is not necessary to form an oil passage communicating with the bore 51 in the housing 50, and productivity is improved.

  Further, since the protrusion 10 is formed integrally with the end face 22 of the cam 20, the lubricating oil supplied to the end face 22 side of the cam 20 can be efficiently received by the protrusion 10, thereby reducing waste of the lubricating oil. Can do. Moreover, since two protrusions 10 are formed on the end surface 22 of the cam 20 at intervals in the circumferential direction, it is possible to reduce the waste of lubricating oil.

  Furthermore, since the oil passage 57 for supplying lubricating oil to the end face 22 side of the cam 20 is formed on the overlapping surface 56 of the upper journal 53, the oil passage 57 can be cast. Therefore, cutting is unnecessary, and the productivity is further improved accordingly.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) The protrusion may be formed only on one of the end faces of the cam. In this case, the oil passage may be formed only on the side corresponding to the end surface on which the protrusion is formed.
(2) Three or more protrusions may protrude from the end face of the cam at intervals in the circumferential direction.
(3) Only one protrusion may protrude from the end face of the cam.
(4) The protrusion may be spaced from the end surface of the cam and protrude from the outer peripheral surface of the camshaft.
(5) The configuration may be such that the oil passage is omitted and lubricating oil is supplied to the end face side of the cam through a shower pipe.
(6) The oil passage may be formed on both the overlapping surfaces of the lower journal and the upper journal.
(7) The oil passage may be formed only on the overlapping surface of the lower journals, not on the upper journal side.
(8) It is not denied that the oil passage is formed by cutting.
(9) The lubrication target is not limited to the lifter only, and for example, a rocker arm or the like is also a target.

DESCRIPTION OF SYMBOLS 10 ... Projection 20 ... Cam 21 ... Cam surface 22 ... End surface 30 ... Cam shaft 40 ... Lifter 43 ... Roller 50 ... Housing (lifter guide)
51 ... Bore 52 ... Sliding surface 53 ... Upper journal 54 ... Lower journal 56 ... Overlapping surface 57 ... Oil passage

Claims (4)

Lifter,
A lifter guide having a bore into which the lifter is reciprocally inserted, and a sliding surface on which an inner peripheral surface of the bore can slide the lifter;
A camshaft disposed adjacent to the lifter guide and extending in a direction perpendicular to the extending direction of the bore;
A cam that is supported by the camshaft and has a cam surface that rotates the camshaft to push the lifter to move the lifter;
The camshaft is configured to project from either the cam or the camshaft in the radial direction of the camshaft, and receives lubricating oil supplied to an end surface side of the cam that intersects the cam surface. A lifter lubrication structure comprising: a protrusion that springs up toward the sliding surface of the lifter guide as the shaft rotates.   The lifter lubricating structure according to claim 1, wherein the protrusion is formed on the end face of the cam.   The lifter lubricating structure according to claim 2, wherein a plurality of the protrusions are formed on the end surface of the cam at intervals in the circumferential direction.   The camshaft is supported between the upper journal and the lower journal, and the lubricating oil is supplied to the end face side of the cam to at least one of the overlapping surfaces of the upper journal and the lower journal. The lifter lubricating structure according to any one of claims 1 to 3, wherein an oil passage is formed.

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