JP6712519B2 - Roller lifter - Google Patents

Description

The present invention relates to a roller lifter.

A roller lifter disclosed in Patent Document 1 is a pump lifter for an internal combustion engine, in which a roller that contacts a rotating cam, a shaft support pin that rotatably supports the roller, and a shaft support pin are installed between a pair of support portions. The lifter main body slides back and forth on the inner wall of the cylinder as the cam rotates. The lifter body is provided with an anti-rotation portion protruding outward, and the anti-rotation portion is engaged with the anti-rotation groove of the cylinder, whereby the relative rotation of the lifter body with respect to the cylinder is restricted. There is.

JP 2012-2115 A

In the above case, the lubricating oil was supplied through the jet (injection means) between the cam and the roller so that the roller smoothly rotates following the rotation of the cam. On the other hand, a sliding area is also formed between the lifter main body and the inner wall (lifter bore) of the cylinder, but heretofore, positive lubrication has not been performed here. However, there is a situation in which the frictional resistance between the lifter body and the lifter bore increases due to the higher rotation speed of the internal combustion engine. Since the rotation direction of the lifter main body with respect to the cylinder is regulated by the rotation preventing portion, there is a problem that wear occurs at a specific position on the outer peripheral surface of the lifter main body.

The present invention was completed in view of the above circumstances, and an object thereof is to provide a roller lifter capable of supplying lubricating oil between a lifter body and a lifter bore.

In the roller lifter of the present invention, a roller that comes into contact with a cam, a shaft member that rotatably supports the roller, and the shaft member are installed between opposing wall portions, and the inner peripheral surface of the lifter bore is rotated as the cam rotates. and a lifter body for reciprocating sliding, the rollers, the lubricating oil supply unit is provided for ejecting the lubricant toward the inner circumferential surface of the Rifutaboa by centrifugal force caused by the rotation of the roller, the lubricant The oil supply part is characterized in that it is constituted by a plurality of radial through holes penetrating the roller in the radial direction of the roller .

When the roller rotates, the lubricating oil is jetted from the lubricating oil supply portion of the roller to the inner peripheral surface of the lifter bore, so that the lubricating oil can be supplied between the lifter bore and the lifter body. As a result, the sliding area between the lifter bore and the lifter body can be lubricated. Further, the lubricating oil can be favorably received by each through hole, and the lubricating oil can be reliably supplied to the inner peripheral surface of the lifter bore.

FIG. 3 is a cross-sectional view of the roller lifter according to the first embodiment of the present invention. It is a front view of a roller lifter. FIG. 7 is a side view of a roller portion of the roller lifter according to the second embodiment.

Preferred forms of the present invention are shown below.
The lubricating oil supply unit may be provided only on the axial end portion of the roller. According to this, it is possible to prevent the influence of the formation of the lubricating oil supply portion from affecting the area where the outer peripheral surface of the roller contacts the cam, and the rotational force of the cam can be transmitted to the roller without any trouble.

<Example 1>
Embodiment 1 of the present invention will be described with reference to FIGS. The roller lifter 10 according to the first embodiment exemplifies a pump lifter provided in a fuel supply device for an internal combustion engine, and includes a roller 20, a shaft member 30, and a lifter body 40. In the following description, the up-down direction is based on each drawing, the left-right direction corresponds to the left-right direction in FIG. 2, and the front-back direction is the right side in the left-right direction in FIG. 1 as the front side.

The lifter main body 40 has a cylindrical peripheral wall portion 41 extending in the vertical direction, and a disc-shaped partition wall portion 42 arranged along the horizontal direction orthogonal to the vertical direction and closing the inside of the peripheral wall portion 41. ing. As shown in FIG. 2, the peripheral wall portion 41 is provided with a pair of left and right support walls 43 that hang down. Both support walls 43 are arranged parallel to each other and have insertion holes 44 that penetrate through them in the left-right direction coaxially.

The peripheral wall portion 41 is provided with a detent portion 45 that protrudes downward from the lower edge of the front end and then bends forward to have a substantially L shape in a side view. Both the support walls 43 and the rotation stopping portion 45 are arranged below the partition wall portion 42 in the vertical direction.

As shown in FIG. 1, the lifter body 40 is vertically reciprocally inserted into a bore 81 of a cylinder head 80 serving as a lifter guide. An anti-rotation groove 82 is provided on the inner peripheral surface of the bore 81 so as to extend in the vertical direction, and the anti-rotation portion 45 is slidably inserted into the anti-rotation groove 82 while the lifter body 40 is reciprocally displaced. It At this time, the anti-rotation portion 45 contacts the groove edge of the anti-rotation groove 82 so that the circumferential displacement of the anti-rotation portion 45 is regulated and the rotation of the lifter body 40 in the bore 81 is regulated. It has become.

A space inside the peripheral wall portion 41 and above the partition wall portion 42 is a storage space 99 into which the lower end portion of the plunger 90, the retainer 91 and the spring member 92 are inserted. The plunger 90 has a rod-like shape that extends in a slender shape in the vertical direction, and a portion protruding upward from the lifter body 40 is slidably inserted into the insertion hole 85 of the cylinder head 80. The upper end of the plunger 90 is capable of advancing and retracting into a pressurizing chamber of a fuel supply passage (not shown).

The retainer 91 is fixed to the outer peripheral surface of the lower end portion of the plunger 90 in the accommodation space 99, and has a plate-like shape that expands in the radial direction of the plunger 90. The spring member 92 is a coil spring and is arranged so as to be sandwiched between the retainer 91 and the inner back surface of the bore 81, and biases the lifter body 40 toward the cam 70.

The shaft member 30 has a columnar pin shape with the axis centered in the left-right direction, and is installed between the support walls 43 with both left and right ends inserted in the insertion holes 44. In the case of the first embodiment, the left and right ends of the shaft member 30 are fixed to both support walls 43 by crimping.

The roller 20 has a cylindrical shape surrounding the outer periphery of the shaft member 30, and is rotatably fixed to the shaft member 30 via a rolling element 60 that constitutes a needle bearing. The rolling element 60 is a needle roller, and a large number of the rolling elements 60 are arranged side by side in the circumferential direction between the roller 20 and the shaft member 30. The lower portion of the roller 20 is exposed below the lifter body 40.

Now, the roller 20 is provided with a lubricating oil supply unit 21. The lubricating oil supply unit 21 receives the lubricating oil jetted toward the left and right end surfaces of the roller 20 from a jet (not shown) as jetting means along the direction of the arrow X, and centrifuges the received lubricating oil as the roller 20 rotates. It is designed to be ejected toward the inner peripheral surface of the bore 81 by the force. Specifically, the lubricating oil supply unit 21 is configured as a through hole 21A that radially penetrates the roller 20 in the radial direction. A plurality of through holes 21A are arranged side by side in the roller 20 at regular intervals in the circumferential direction. Each of the through holes 21A is formed so as to open across the outer peripheral surface and the inner peripheral surface of the roller 20 and the end surfaces (both left and right end surfaces), and extends over the entire radial direction on the end surface of the roller 20. It has a groove shape (see FIG. 1) and a U-shaped notch shape in a front view (see FIG. 2).

The outer peripheral surfaces of the left and right end portions of the roller 20 are retracted from the outer peripheral surface of the cam 70 by crowning, and are curved non-contact regions 22 that do not substantially contact the cam 70. Each of the through holes 21A of the lubricating oil supply unit 21 is open in the non-contact area 22 of the roller 20. On the outer peripheral surface of the roller 20, the left and right central portions excluding the non-contact area 22 are contact areas 23 in contact with the cam 70. Therefore, the influence of the opening of each through-hole 21A does not substantially affect the contact area 23 in contact with the cam 70.

Next, the function and effect of the roller lifter 10 according to the first embodiment will be described.
When the cam 70 rotates about the cam shaft 71 and the roller 20 is driven to rotate, the lifter main body 40 reciprocally slides up and down in the bore 81 at a stroke corresponding to the lift amount of the cam 70, and accordingly the partition wall portion. The plunger 90 supported by 42 also reciprocates vertically. As a result, the upper end of the plunger 90 is displaced forwards and backwards due to pressurization, and the hydraulic oil is pumped in the fuel supply passage.

Lubricating oil is supplied between the roller 20 and the cam 70 and each rolling element 60 of the needle bearing from the X direction in the drawing through a jet, and the supplied lubricating oil causes the contact area 23 of the roller 20 and the cam 70 to move. The space between them is lubricated. Further, the lubricating oil adheres to the non-contact area 22 of the roller 20, and further the lubricating oil temporarily enters and is received by each through hole 21A of the lubricating oil supply portion 21. The lubricating oil received by each through hole 21A is scattered outward in the radial direction by the centrifugal force that accompanies the rotation of the roller 20. The scattered lubricating oil mainly adheres to a region F of the inner peripheral surface of the bore 81 facing in the rotation direction of the cam 70, and this region F is in sliding contact with the outer peripheral surface of the peripheral wall portion 41 of the lifter body 40. Thus, the space between the bore 81 and the lifter body 40 is lubricated.

By the way, the lifter main body 40 is in a state called cocking in which the lifter main body 40 tilts in the direction along the rotational direction of the cam 70 in the gap range with the inner peripheral surface of the bore 81 and hits the inner peripheral surface of the bore 81 one-sided. There is a high possibility of wear. In particular, since the rotation preventing portion 45 restricts the rotation of the lifter body 40 in the bore 81, there is a concern that the progress of wear in the region F may be accelerated. However, in the case of the first embodiment, while the lifter main body 40 is reciprocally displaced, the centrifugal force accompanying the rotation of the cam 70 is used to lubricate from the respective through-holes 21A of the lubricating oil supply portion 21 toward the region F of the lifter main body 40. Since the oil is abundantly supplied, the lubricity of the lifter body 40 and the bore 81 can be ensured well, and the occurrence and progress of wear in the region F can be suppressed.

Further, in the case of the first embodiment, since the through holes 21A are provided only at the left and right ends of the roller 20, the through holes 21A are formed in the contact area 23 where the outer peripheral surface of the roller 20 contacts the cam 70. Can be prevented, and the rotational force of the cam 70 can be transmitted to the roller 20 without any trouble.

Further, since each through-hole 21A radially penetrates the roller 20, the lubricating oil can be favorably received by each through-hole 21A, and a large amount of lubricating oil can be supplied to the inner peripheral surface of the bore 81. it can. Further, the lubricating oil can be supplied also to the rolling elements 60 of the needle bearing through the through holes 21A.

<Example 2>
FIG. 3 shows a second embodiment of the present invention.
Unlike the first embodiment, the lubricating oil supply unit 21 of the second embodiment does not radially penetrate the roller 20B, but opens on the outer peripheral surface of the roller 20B but does not open on the inner peripheral surface of the roller 20B. It is in the form. Specifically, a large number of lubricating oil supply parts 21 are arranged side by side at regular intervals in the left and right ends of the roller 20B, and are opened from the outer peripheral surface of the roller 20B to the end faces (left and right end faces) U. It is configured as a notch-shaped recess 21B.

Lubricating oil is supplied to the end surface of the roller 20B from a jet (not shown), and when the supplied lubricating oil is received by the recesses 21B, lubrication is performed from the recesses 21B to the inner peripheral surface of the bore 81 as the roller 20B rotates. Oil is jetted. The lubricating oil thus ejected adheres to the inner peripheral surface of the bore 81 and lubricates between the lifter body 40 and the bore 81, so that the occurrence and progress of wear of the lifter body 40 can be suppressed. This point is the same as in the first embodiment. However, in the case of the second embodiment, the lubricating oil stays in each recess 21B for a short time, so that the lubricating oil can be quickly supplied to the inner peripheral surface of the bore 81.

<Other Examples>
Another embodiment will be briefly described below.
(1) The lubricating oil supply part may be formed to have a rectangular cross section.
(2) The lubricating oil supply unit may be provided only at one end of the left and right ends (both ends in the axial direction) of the roller.
(3) The lubricating oil supply section may be configured by a gear-shaped or windmill-shaped blade attached to the end surface of the roller.
(4) The roller lifter of the present invention can be applied to a valve lifter in a valve train of an internal combustion engine. In this case, the structure of the roller lifter is similar to that of the first embodiment, but the plunger is formed as a valve stem.

10... Roller lifter 20, 20B... Roller 21... Lubricating oil supply part 21A... Through hole 21B... Recessed part 30... Shaft member 40... Lifter body 80... Cylinder head 81... Bore

Claims (2)

A roller that contacts the cam,
A shaft member on which the roller is rotatably supported;
The shaft member is provided between the opposing wall portions, and the lifter body is configured to reciprocally slide on the inner peripheral surface of the lifter bore as the cam rotates,
The roller is provided with a lubricating oil supply unit for ejecting the lubricating oil toward the inner peripheral surface of the lifter bore by a centrifugal force caused by the rotation of the roller ,
A roller lifter characterized in that the lubricating oil supply section is constituted by a plurality of radial through holes penetrating the roller in a radial direction of the roller . The roller lifter according to claim 1, wherein the lubricating oil supply portion is provided only on an axial end portion of the roller.

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