JPH0536006U - Tapest - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain a tappet capable of easily replacing a shim without lowering the strength and rigidity of the shim fitting portion. [Structure] A vertical groove (6) recessed outward is formed on the inner peripheral surface of the side wall (2b) connected to the upper end of the body (2) from the upper end of the side wall (2b) to the upper wall (2a). By being formed so as to be continuous with the upper surface,
A vertical gap (C) is formed between the shim (3) and the side wall (2b), and a wire or the like is inserted through the gap (C) or compressed air is blown into the shim (3) to remove the shim (3). Can be easily removed. Further, since the side wall (2b) is continuous, even if the entire body (2) is molded with aluminum alloy or the like,
The strength and rigidity of the fitting portion of the shim (3) will not decrease.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a tappet used in a direct-acting valve operating mechanism, and more particularly to a tappet that facilitates replacement of a shim for valve clearance adjustment.

[0002]

[Prior Art]

 FIG. 7 schematically shows a direct-acting type valve operating mechanism that is widely used in DOHC engines. Therefore, the engine valve (01) includes a pair of cotters (02) (02), a spring retainer (03), It is attached to the cylinder head (05) by a valve spring (04) and the like.

At the upper end of the engine valve (01), a cylindrical iron tappet (06) whose upper surface is closed is provided with an inner bottom surface of a circular upper wall (07) of the engine valve (01) stem. It is inserted from above so that it touches the end.

A disc-shaped recess (09) is formed inside the annular side wall (08) connected to the upper part of the upper wall (07), and a valve is provided in this recess (09). A clearance adjustment shim (010) is fitted.

In the engine valve (01), the entire tappet (06) guided by the cylinder head (05) is pushed by the rotating cam (011) brought into contact with the upper surface of the shim (010). Can be opened and closed.

In such a direct-acting type valve operating mechanism, when the valve clearance is adjusted, the tappet (06) is pushed downward by an appropriate jig, and the shim (010) having a different thickness is used. However, since the shim (010) and the upper surface of the upper wall (07) are in intimate contact with each other via lubricating oil, the removal is very troublesome.

Therefore, as shown in FIG. 8, the conventional tappet (06) is relatively opposed to the annular side wall (08) continuously provided on the upper part of the upper wall (07) by 180 ° in the circumferential direction. A pair of slotted notch grooves (012) are formed, and a driver or the like is inserted into the notch grooves (012) to remove the shim (010).

[0008]

[Problems to be solved by the device]

 Recently, the demand for higher engine speed and higher output has led to a demand for even lighter valve trains, and tappets tend to shift from conventional iron products to aluminum alloy products.

The aluminum alloy tappet is inferior in strength and rigidity to that made of iron. Therefore, when the notch groove (012) is formed in the annular side wall (08) as in the conventional case described above, the engine speed is particularly high. When the valve system is improperly moved during rotation and a strong outward load is applied to the side wall (08), stress may be concentrated in the notch groove (012) and the side wall (08) may be damaged. is there. Further, since the holding area of the outer peripheral surface of the shim (010) is small, it is possible that the shim may fall off during improper movement.

The present invention has been made to solve the above problems, and provides a tappet capable of easily replacing a shim without reducing the strength and rigidity of the shim fitting portion. It is an object.

[0011]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention has an upper wall of a cylindrical body whose upper surface is closed, and an annular side wall is connected to the upper side of the body in an upward direction, and a valve clearance adjustment is provided in a recess surrounded by the side wall. In the tappet in which the shim of (3) is detachably fitted, a part of the inner surface of the side wall or the outer peripheral surface of the shim is recessed outward or inward, respectively. As a result, a vertical groove extending from the upper end of the side wall or shim to the upper end surface of the body is provided.

[0012]

The vertical groove extending from the upper end of the side wall to the upper end surface of the body is formed on one of the inner peripheral surface of the side wall and the outer peripheral surface of the shim connected to the upper end of the body. A gap facing vertically is formed between the gaps, and the shim can be easily removed by inserting a wire or the like or blowing compressed air through the gap. Further, since the side walls are continuous, even if the body is made of an aluminum alloy or the like, the strength and rigidity of the shim fitting portion will not be reduced.

[0013]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show a first embodiment of the present invention, in which a tappet (1) is a cylindrical body (2) formed of a light alloy such as an aluminum alloy and a chromium or chrome molybdenum. It consists of a disk-shaped shim (3) formed of a wear-resistant metal material such as steel. The shim (3) is located above the upper wall (2a) of the body (2) as in the conventional example described above. It is removably fitted in a recess (4) surrounded by annular side walls (2b) continuously provided.

An annular clearance groove (5) for polishing the upper surface of the upper wall (2a) is formed at a corner between the upper wall (2a) and the side wall (2b). On the inner peripheral surface of the side wall (2b), a pair of vertical grooves (6) and (6) that are recessed outward in an arc shape to approximately half the thickness thereof are 180 ° in the circumferential direction. It is formed so as to be spaced apart and opposed, and its lower end communicates with the escape groove (5).

When the vertical groove (6) as in the first embodiment is formed, a gap (C) facing in the vertical direction is formed between the outer peripheral surface of the shim (3) and the inner peripheral surface of the side wall (2b). Therefore, insert a wire-like extraction jig (not shown) from this gap (C) and pull up the shim (3), or blow compressed air through the gap (C) with an air gun etc. The shim (3) can be easily pulled out from the recess (4) by raising the.

Moreover, since the side wall (2b) is continuous and is not cut as in the conventional case, even if the entire body (2) is molded with a lightweight material such as aluminum alloy, the strength and rigidity are reduced. Since the holding area of the shim (3) does not become so small, there is no fear that the shim (3) will fall out even if an improper movement occurs.

FIG. 3 shows a second embodiment of the present invention. In contrast to the above, this embodiment forms an arc on the outer peripheral surface of the shim (3) toward the centering direction (inward). A pair of recessed vertical grooves (7) (7) are formed to face each other.

Also in the second embodiment, the shim (3) can be easily removed by the same method as in the first embodiment, and the strength of the side wall (2b) does not pose a problem. In this second embodiment, instead of the vertical groove (7), as shown in FIG. 4, the outer peripheral surface of the shim (3) is slightly cut off to form a flat surface portion (8), and the side wall (2b ) And a gap (C) may be formed.

5 and 6 show a third embodiment of the present invention, in which the spiral groove (9) communicating with the vertical groove (6) is formed on the upper surface of the upper wall (2a). In the case of FIG. 6, a circular recess (10) is formed in the central part of the upper wall (2a), and four grooves are connected from the recess (10) to the vertical groove (6) and the escape groove (5). The radiation grooves (11) are formed respectively.

When the spiral groove (9) and the radial groove (11) are formed, the compressed air blown from the vertical groove (6) is applied to the contact surface between the shim (3) and the upper wall (2a). It's easier to get in, and the shims (3) will come up easily.

Further, since the spiral groove (9) and the radial groove (11) serve as an oil reservoir to improve the oil retaining property of the lubricating oil, the rotational force is applied when the rotating cam (not shown) is contacted. The shim (3) which has been made to rotate smoothly, and further, it is possible to suppress the abrasion of the contact surfaces between the upper wall (2a) and the shim (3). Incidentally, it goes without saying that the vertical grooves 6 and 7 in each of the above embodiments may be one.

[0022]

[Effect of the device]

 According to the present invention, either the inner peripheral surface of the side wall or the outer peripheral surface of the shim is recessed outward or inward to form a gap for removing the shim, and the shim can be easily removed from this gap. Since it can be removed, it is not necessary to cut out the side wall as in the conventional case. Therefore, even if the body is molded with an aluminum alloy or the like, there is no fear that the strength and rigidity of the shim fitting portion will decrease.

[Brief description of drawings]

FIG. 1 is a central vertical sectional front view showing a first embodiment of the present invention.

FIG. 2 is a perspective view of the same.

FIG. 3 is a perspective view showing a second embodiment of the present invention.

FIG. 4 is a plan view in which the shape of the vertical groove of the shim is also changed.

FIG. 5 is a perspective view showing a third embodiment of the present invention in which a spiral groove is formed on an upper end surface of a body.

FIG. 6 is likewise a perspective view showing an example in which a radiation groove is formed on the upper end surface of the body.

FIG. 7 is a central longitudinal front view schematically showing a conventional tappet and a direct-acting valve operating mechanism.

FIG. 8 is likewise a perspective view of a conventional tappet.

[Explanation of symbols]

 (1) Tappet (2) Body (2a) Upper wall (2b) Side wall (3) Shim (4) Recess (5) Escape groove (6) (7) Vertical groove (8) Plane section (9) Spiral groove ( (Groove) (10) Groove (11) Radial groove (Groove) (C) Gap

Claims (2)

[Scope of utility model registration request] 1. A ring-shaped side wall is continuously provided upwardly on an upper end portion of a cylindrical body whose upper surface is closed, and a shim for valve clearance adjustment is attachable / detachable in a recess surrounded by the side wall. In a fitted tappet, on one of the inner peripheral surface of the side wall or the outer peripheral surface of the shim,
A tappet, characterized in that a vertical groove extending from the upper end of the side wall or the shim to the upper end face of the body is provided by recessing a part of them inward or outward, respectively. 2. The tappet according to claim 1, wherein a concave groove communicating with the vertical groove is formed on the upper end surface of the body.