JPS58185913A - Valve gear of internal-combustion engine - Google Patents

Abstract

PURPOSE:To minimally reduce knocking noise which is generated when a valve gear lifter slides in a guide hole by providing sliders of synthetic resin in either one of the external face of a cylindrical shell of the valve gear lifter or the internal face of the guide hole. CONSTITUTION:A retainer 13 is tightly fit to the upper end of a valve stem 11 with a two-split cotter 14 and one end of a valve spring 17 is engaged to the upper face of the retainer 13 to push the valve stem 11 upwards, namely, in the closing direction. A valve lifter 19 which consists of a shell 23 and a pressure receiving plate 24 is slidably engaged in a guide hole 21 of a cylinder head 20 while an outer pad 31 is engaged in an engagement hole 29 in the pressure receiving plate 24 and makes slidable contact with a valve gear cam 33. A groove 19a is formed on the external face of the valve lifter 19 and a ring 19b or a slider which is made of synthetic resin is fit in the groove. The shell 23 and the guide hole 21 make slidable contact via the ring 19b, whereby knocking noise generated when they slide each other may be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an internal combustion engine with an over-rad cam shape (OHO type), in particular to a valve train that is pressed by a valve train cam and slides inside a cylinder head to open and close intake valves and exhaust valves. An object of the present invention is to reduce as much as possible the knocking noise caused by collision with a wall surface when the lifter slides through a guide hole in a cylinder head.

In recent years, among automobiles? Some engines have cylinder heads made of aluminum alloy to reduce weight. This ridge cylinder head has a higher thermal tensile modulus than conventional cast iron ones, so if the gap between the lifter and its guide hole is set to the required size when the machine is cold, the gap will become too large after 8 aircraft. Therefore, when the lifter slides, it tends to make a clicking sound. This invention eliminates such problems (a feature of the present invention is that a sliding body made of synthetic resin is provided on one side of the outer periphery of the body of the lifter and its guide hole, and the sliding contact is made with the other through it. .

The present invention will be explained below based on the illustrated embodiments.

The figure shows a valve operating mechanism. In the figure, reference numeral 11 denotes a valve stem, and a retainer 13 is fixed to the upper end of the valve stem by a two-split bolt 15. One end of a valve spring 17 engages with the lower surface of this retainer 13 to press the valve stem 11 upward, that is, in the valve closing direction. Reference numeral 19 denotes a valve valve 7, which fits into a guide hole 21 formed by 5J in a part of the cylinder head 20 made of aluminum alloy and slides therein. The valve valve 7 19 consists of a cylindrical body 23 and a pressure receiving plate 24 that closes one end of the body.
Made of one piece of steel and hardened.

An outer pad fitting hole 29 is bored in the pressure receiving plate 24 of the lifter, and an outer band 61 made of hardened, tempered steel and polished on both sides is fitted into the fitting hole 29, and the valve drive cam is fitted with an outer pad fitting hole 29. Layer liquid at 3'5.

Here, the outer band 61 is used to adjust the valve clearance by replacing the outer band 61 with one having a different thickness. 34 is an inner pad interposed between the small cylindrical projection 25 protruding from the lower surface of the pressure receiving plate 26 and the top surface of the valve stem 11.

A decoy rubbing body made of synthetic resin is provided on the outer periphery of the valve valve 7ta 19. That is, a groove 19& is provided on the outer circumferential surface of the chest, and a ring 19b made of synthetic resin, for example, 6-6 nylon (trademark) is attached by WC. FIG. 2 shows another embodiment. In this case, a cylinder 190 made of synthetic resin is fitted over the entire outer surface of the body 23.

In the valve operating mechanism of the present invention, the valve operating cam 33 pushes down the valve lifter 19 via the outer pad 31, and the valve lever 7 presses the valve stem 11 downward or disappears upward, thereby opening and closing the valve. .

Note that in the above embodiment, the ring 19b and the cylinder 19c
does not necessarily need to be provided in the valve lifter 19 (, guide hole 2
It may be provided within 1.

As described above, in this invention, a sliding body made of synthetic resin is provided on one side of the cylindrical body portion 23 and its guide hole 21, and the liquid is brought into contact with the other through the sliding body. If the gap between the engine body and the other body is properly adjusted when the engine is cold, even if the guide hole 21 becomes large in diameter due to the heat If when the engine is warmed up, the sliding body itself will expand, so the guide hole 21 The gap between the two does not become excessively large. Furthermore, since synthetic resins generally have a small scale friction coefficient, they have the effect of reducing engine friction loss.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a mounting part showing one embodiment of the present invention, and FIG. 2 is a front view of the same part showing a modification thereof. 19... Valve lifter 19'b, 19o... Sliding body (ring, cylinder) Patent applicant Yamaha m+ki Co., Ltd. Figure 1 Figure 2

Claims (1)

[Claims] On one side of the outer peripheral surface of the cylindrical chest and the inner peripheral surface of the guide hole,
A valve train for an internal combustion engine is provided with a sliding member made of synthetic resin and is made to come into sliding contact with the other member through the sliding member.