JPH0639043Y2 - Valve lifter for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a valve lifter for an internal combustion engine.

[Conventional technology]

Conventionally, as can be seen from FIG. 4 and FIG. 5, in the valve train of DOHC, when the cam nose 12a pushes down the shim (adjusting shim) 11 'by the rotation of the cam 12, the valve lifter 7 causes the valve guide of the head cylinder 1 to move. 2, the intake / exhaust valve 3 is opened and closed.

Since a frictional force acts between the cam nose 12a and the shim 11 ', the shim 11' is pushed laterally and repeatedly collides with the shim wall surface 19 of the valve lifter 7.

In addition, in order to improve the engine output, fuel efficiency and noise, it is necessary to reduce the weight of valve operating system parts. Therefore, the valve lifter 7 made of aluminum is molded from quenched powder hot extruded aluminum material,
As shown in FIG. 7, a surface layer having abrasion resistance is provided on the outer peripheral surface 21 of the cylindrical portion 20 and the contact surface 23 of the disc portion 22 to deal with the problem. It is described in Japanese Patent Application No. 60-181530 (see Japanese Utility Model Laid-Open No. 62-90907).

A conventional example in which the shim 11 'is replaced from the valve lifter 7 is shown in FIGS. 6 and 7, and the lower part is hooked on the lifter guide 25 and the upper part is hooked on the valve lifter 7 with a scissor-shaped removal tool 24. Shim valve lifter 7
Push down together with 11 'and remove the shim 11' from the notch 26 of the valve lifter 7 with a screwdriver 27 or the like.

At this time, the oil is usually present between the shim 11 'and the valve lifter 7, and the shim 11' is in close contact with the valve lifter 7 due to the surface tension of the oil.

Furthermore, FIG. 8 also shows the actual application filed previously by the applicant.
No. 61-65238 (see Japanese Utility Model Laid-Open No. 62-176406), the valve lifter 70 has a passage 28 such as a groove for communicating the back surface of the shim 110 with the outside, and the shim 110 and the valve lifter 70. Is provided between or on the top surface 7a of the valve lifter 70, and supplies hydraulic pressure or air pressure to the passage 28,
The shim 110 is removed from the valve lifter 70.

Further, Japanese Utility Model Laid-Open No. 57-76208 discloses a configuration in which a passage communicating with the valve lifter from the cam side is provided in the shim in order to supply lubricating oil between the bottom surface of the shim and the bottom surface of the recessed portion of the top surface of the valve lifter. Has been done.

[Problems to be solved by the invention]

However, in the case of the aluminum valve lifter of the internal combustion engine shown in FIGS. 4 and 5, the repetitive load of the shim (adjusting shim) 11 ′ on the shim wall surface 19 of the valve lifter 7 is for removing the shim provided in the valve lifter 7. When it is applied to the vicinity of the notch portion 26 (see FIGS. 6 and 7), stress is likely to concentrate on that portion. Therefore, if the material of the valve lifter 7 is aluminum or the like and the fatigue strength is low, the valve lifter 7 is provided. The notch (hole) 26 for removing the shim may be damaged.

As described above, when the notch (hole) 26 for removing the shim is provided in the valve lifter 7, stress concentration occurs at the notch (hole) 26, so that it is difficult to achieve it especially with an aluminum material having low fatigue strength. May be.

Therefore, in order to solve such a problem, the present invention suppresses the strength reduction of the valve lifter by devising and improving the disposition portion such as a notch for removing the shim, and is made of a lightweight aluminum. The purpose of the invention is to make the tappet clearance easy as well as to be applicable to a valve lifter.

[Means for solving problems]

Therefore, this invention eliminates the above-mentioned problem by eliminating the notch or hole for removing the shim on the valve lifter side, and providing a small hole for removing the shim on the shim (adjusting shim) side.
This is to solve the problem by adjusting the angle.

More specifically, the reference numeral of FIG. 1 will be used for explanation. A recess 10 is provided on the top surface 7a of the valve lifter 7, and a shim 11 is detachably arranged in the recess 10 and is in contact with the shim 11. In a valve lifter of an internal combustion engine configured to push down the valve lifter 7 via the shim 11 by the cam nose 12a of the cam 12, a small hole 13a for removing the shim is provided through the shim 11 in the thickness direction of the shim. It is a thing. Furthermore, the small hole 13a is provided to be inclined with respect to the thickness direction of the shim, and the inclination of the small hole 13a is from the shim radial outer side to the center side from the shim 11 upper surface in contact with the cam 12 to the valve lifter side lower surface. It is a slope that goes toward.

[Action]

According to the above means, the blower 16 or the air gun 17 or the like (see FIG. 2) blows air into the small hole 13a for removing the shim provided on the side of the shim 11 to eject the shim 11 from the valve lifter 7. The shim 11 can be removed and the tappet clearance is adjusted. Further, in the present application, the small hole 13a is the shim 1
Since the air is blown from the upper surface of 1 toward the center of the lower surface, the air blown from the small holes 13a on the upper surface of the shim 11 is
Along the slope of the small hole 13a, the shim 1
The air is blown between 1 and the valve lifter 7, so that the air spreads from the center side of the lower surface of the shim 11 in a substantially radial manner, and the shim 11 is uniformly peeled off.

〔Example〕

An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 and FIG. 2 show a first embodiment of the present invention. In the DOHC valve system, the stem 3a of the intake / exhaust valve 3 is inserted into the valve guide 2 provided in the cylinder head 1,
A spring retainer 5 is fixed near the free end 30 of the stem 3a of the intake / exhaust valve 3 via a cotter 4, and a valve spring 6 is stretched between the spring retainer 5 and the cylinder head 1. is there.

Next, the free end 30 of the stem 3a of the intake / exhaust valve 3 is brought into contact with an inner shim 8 formed on the back surface of the valve lifter 7 made of aluminum.
It is provided slidably in the valve lifter insertion hole 9 provided in the.

A recess 10 is provided on the top surface 7a of the valve lifter 7 made of aluminum, and a shim (adjusting shim) 11 is detachably arranged in the recess 10 so that the cam nose of the cam 12 contacting the shim 11 can be removed. By 12a, the valve lifter 7 is pushed down via the shim 11.

Since the shim 11 is provided with diagonal small holes 13a for removing the shim (inclined at an angle α in FIG. 1) at two locations (13a, 13a) parallel to the shim center line. The front and back sides of the shim 11 do not need to be identified when the shim 11 is attached to the valve lifter 7.

Further, the hole position of the small hole 13a is set in a range from the center of the shim where the cam 12 and the shim 11 are always in contact with each other, avoiding the position where the positive acceleration of the valve lifter 7 is high and the contact load is high.

Then, as shown in FIG. 2, from the valve lifter 7 to the shim 11
To remove the shim 11, a blower 16 having a nozzle 15 having a tip diameter smaller than the hole diameter of the small hole 13a, an air gun 17 or the like is used to blow compressed air to remove the contact between the shim 11 and the valve lifter 7 due to the oil. After being ejected from the valve lifter 7, the shim 11 is removed from the valve lifter 7 by adsorbing it to a magnet 18 or the like as shown in FIG.

Thus, in this embodiment, since compressed air is used, the valve lifter 7 is prevented from being twisted, damage to the valve lifter 7 can be prevented, and air is blown out from the center side of the lower surface of the shim 11. When the shim 11 is ejected from the valve lifter 7, the outer peripheral edge of the shim 11 does not get caught on the wall of the recess 10 of the valve lifter 7, so that the shim can be replaced easily and surely, and the work efficiency can be improved. it can. Further, since the notch for removing the shim is not provided on the shim wall surface of the valve lifter 7 and the outer peripheral edge portion of the shim 11, there is no shape factor that causes stress concentration, and the valve lifter is made lightweight by using an aluminum material or the like. Is also an adaptive configuration.

Further, by forming a small hole 13a in the shim 11, a lubricating oil film is easily formed between the valve lifter 7 and the shim 11, so that there is an effect of preventing wear on the valve lifter 7 side.
The effect of reducing the tapping sound between the valve lifter 7 and the shim 11 is also produced.

[Effect of device]

In this invention, the notch or hole for removing the shim on the valve lifter side is eliminated and a small hole for removing the shim is provided on the shim (adjusting shim) side, so the fatigue strength of the valve lifter is increased and its strength is improved. At the same time, the tappet clearance can be easily adjusted.

Furthermore, since the small holes are provided so as to be inclined toward the center side of the bottom surface of the shim, air is blown toward the center side of the bottom surface of the shim, the air spreads in a substantially radial manner, and the shim is peeled off uniformly on the front surface. It is possible to reduce problems such that only one side of the shim floats and the outer peripheral edge portion of the shim gets caught in the recessed wall portion of the valve lifter, and it becomes easy to replace the shim, that is, adjust the tappet clearance.

[Brief description of drawings]

1 and 3 show an embodiment of the present invention, in which FIG. 1 is a sectional view, FIGS. 2 and 3 are perspective views showing the removal of a shim, and FIGS. 4 to 8 are shown. 4 shows a conventional example, FIG. 4 is a cross-sectional view corresponding to FIG. 1, FIG. 5 is a cross-sectional view of a valve lifter showing one conventional example, and FIG. 6 uses a removal-dedicated tool. FIG. 7 is a perspective view showing a state in which the shim is removed using a special removal tool and a driver, and FIG. 8 is a sectional view showing another conventional example. 7 …… Valve lifter 7a …… Top surface 10 …… Indentation 11 …… Shim 12 …… Cam 12a …… Cam nose 13a …… Small hole

Continuation of the front page (56) References Microfilm (JP, U), which is a photograph of the contents and drawings attached to the application for Japanese Patent Application No. 58-162619 (No. 60-69303). A microfilm (JP, U) of the contents and drawings attached to the application for No. 56-145404 (Shokai No. 58-48905)

Claims (1)

[Scope of utility model registration request] 1. A recess is provided on the top surface of a valve lifter, and a shim is detachably disposed in the recess, and a cam nose of a cam contacting the shim presses down the valve lifter through the shim. In the valve lifter for an internal combustion engine, the shim is provided with a small hole for removing the shim penetrating in the thickness direction of the shim, which is inclined with respect to the thickness direction of the shim, and the inclination of the small hole is from the upper surface in contact with the cam. A valve lifter for an internal combustion engine, wherein the valve lifter is inclined toward the center side from the outside in the shim radial direction toward the lower surface on the valve lifter side.