JPS62267512A - Tappet valve device for internal combustion engine - Google Patents

Abstract

PURPOSE:To reduce the required number of parts and obtain a tappet valve device that is inexpensive and easy to assemble by connecting two slippers touching each one end of the valve stems of two intake valves or exhaust valves by means of an intermediate sliding guide part so that they are incorporated in a body. CONSTITUTION:The upper ends of the valve stems of two intake valves or exhaust valves 10, 10 having the same function are engaged with holes 24 in the under surface of slippers 21, 21 respectively. The upper surface of the slippers 21, 21 are touched to cams 13, 13, and the two slippers 21, 21 are connected to each other by means of sliding surfaces 26, 26. The external walls of the sliding surfaces 26, 26 are engaged with a sliding guide part 22 provided on a cylinder head. Hereby, when the cams 13, 13 rotate, the two slippers 21, 21 move up and down as they are solidly guided by the guide part 22 and drive the two valves 10, 10.

Description

Detailed Description of the Invention A1 Objective of the Invention (1) Industrial Application Field The present invention comprises two poppet valves (two intake valves or exhaust valves) having the same function, such as 3.4 valve two. 4
The present invention relates to a valve train in a cycle internal combustion engine.

(2) Conventional technology Conventionally, in a four-stroke internal combustion engine with three or more valves, a pair of poppet valves (intake valves or exhaust valves) with the same function are slid on the cylinder head to open and close the intake or exhaust port leading to the combustion chamber. A valve lifter that is movably supported and is slidably guided to the cylinder head is provided at the upper end of the stem portion of these poppet valves, and the valve drive cam is directly or A cam follower is connected to this.

(3) Problems to be Solved by the Invention However, in the conventional valve lifter described above, a valve lifter is provided for each pair of poppet valves (intake valve or exhaust valve), and each lifter must slide without tilting. Therefore, it has a relatively long guide sliding part, which results in an increase in weight, and the proportion of the weight occupied by the valve lifter in the valve train becomes large.
In particular, this is a cause that hinders the performance improvement of high-speed engines.

B6 Structure of the Invention (Means for Solving 11 Problems) The present invention was made in view of the above-mentioned circumstances, and consists of one valve lifter and a pair of poppet valves (intake valve or exhaust valve).
It is an object of the present invention to provide a valve train for an internal combustion engine with a simple structure, which can be used in common with the valve train to significantly reduce its weight, thereby solving the above-mentioned problems.

(2) Effect According to the above configuration, it is possible to reduce the reciprocating mass of the valve mechanism by sharing the valve lifter with the pair of poppet valves and reducing the weight, resulting in a significant improvement in engine performance. can contribute.

(3) Embodiments Hereinafter, embodiments in which the present invention is implemented in a DOHC OHC type internal valve engine will be described with reference to the drawings.

The engine main body E of the engine includes a cylinder block 1 and a cylinder head 2 which is superimposed and bonded to the deck surface of the cylinder block 1 through a gasket 1-.

The cylinder head 2 is formed with a combustion chamber 5 facing the upper surface of the piston 4 that is slidably engaged with the cylinder bore 3 of the cylinder block 1, and an intake boat 6.6 and an exhaust port 7.7 that communicate with the combustion chamber 5. , the intake boat 6.6 and the exhaust port 7.7 are connected to a pair of intake valves 10.10 which are vertically and slidably supported on the cylinder head 2 via valve guide members 8, 8:9. Exhaust valve 11.1
1 is opened and closed. The intake and exhaust valves 10, 10; 1
1 and 1 are umbrella-shaped valve portions 10. ．． 11, and stem portions 10□, 11□ extending integrally from this poppet valve.

On the pair of intake valves 10.10, an intake side valve operating camshaft 12 with an integrally provided intake cam 13.13 is disposed, and rotation of the camshaft 12 directly opens and closes the intake valves 10.10. , and an exhaust cam L5. on the pair of exhaust valves 11.
An exhaust side valve operating camshaft 14 is provided with L5 integrally provided,
The rotation of the camshaft 14 directly opens and closes the exhaust valves 11.11.

Since the structure of the valve train of the intake valve 10.10 and the exhaust valve 11.11 is the same, the intake valve 10.10 will be described below.
The structure of the valve train 10 will be explained with reference to FIGS. 2 to 4. The cylinder head 2 includes a pair of intake valves 10, 10, and 10's stem portion 10. ．． A recess 16 having an oval cross section is formed to surround the upper half of the intake valve 101, and a valve spring 17.17 for biasing the intake valve 10.10 in the valve closing direction is housed in the recess 16. . The response spring 17 is connected to the intake valve 10
The upper spring receiver 19 is fitted onto the upper part of the stem portion 10z of the valve 10z via the lever 18, and the lower spring receiver 20 is seated on the bottom surface of the recess 16. I am assisted.

One valve lifter L is provided at the upper ends of the pair of intake valves 10.10, spanning them. As shown in FIG. 4, this valve lifter L consists of a pair of slipper parts 21.21 arranged in parallel with an interval, and a sliding guide part 22.22 that integrally connects these slipper parts 21.21. The slipper portion 21.21 has a rectangular planar shape, and flat slipper surfaces 23, 23 are formed on the upper surface of the slipper portion 21.21.
The cam surface of the intake cam 13.13 is pressed into contact with the intake cam 13.13, and as the intake cam 13.13 rotates, the cam surface comes into sliding contact along the longitudinal direction of the slipper surface 23.23.

Further, bottomed engagement holes 24, 24 are formed in the center of the lower surface of the slipper portion 21.21, and these engagement holes 24.
24, the intake valves 10, 10 are connected via adjustment shims 25, 25.
The upper ends of the stem portions 102, 102 of are engaged.

The valve gap of the intake valve 10.degree. 10 is adjusted by replacing the adjusting shims 25, 25 with different thicknesses. Said print! l
]g The inner parts 22.22 extend downward at substantially right angles to the slipper part 21.21, and flat sliding surfaces 26.26 are formed on their outer surfaces, and these sliding surfaces 26.26
is a guide receiving surface 27 formed on the opposing inner surface of the recess 16.
27 so as to be slidable up and down.

Note that 28 in the figure is a spark plug.

Stem portions 11g, 11 of the pair of exhaust valves 11.11
The structure of the valve operating section including the valve lifter L provided at the upper end of the valve z is also completely the same as that of the pair of intake valves 10 and 10, so a description thereof will be omitted.

Next, the operation of this embodiment will be explained.

If the intake and exhaust side valve drive camshafts 12 and 14 are now rotated due to the operation of the engine, the intake and exhaust valves 1 are rotated as usual.
0, 10; 11, 11 are opened and closed at predetermined timing.

Thus, a pair of intake valves 10, 10, and a pair of exhaust valves 1
1.11 are actuated by the rotation of the intake cam 13.13 and the exhaust cam 15.15 through one valve lifter L, L.

The valve lifter L is moved vertically in parallel by the cam surface of the intake cam 13.13 (exhaust cam 15, 15) being pressed against the slipper surface 23.23 of the valve lifter L, and the intake valve 10.
10 (exhaust valve 11.11). In addition, the valve lifter L has an intake cam 13.13 (exhaust cam 15.15).
) (in the direction of arrow A in Figure 4)
The sliding surface 26.26 of the sliding guide portion 22 of the valve lifter L is subjected to a force perpendicular to the vertical movement direction of the intake valve 10.10 (exhaust valve 11.11).
By being received by the guide receiving surfaces 27.27 formed in the valve lifter L, the valve lifter L does not tilt or rotate.

Further, since the guide receiving surface 27.27 is a flat surface, the component force in the horizontal direction acts uniformly on the guide receiving surface 27.27, reducing the pressure receiving surface of the guide receiving surface 27.27. Not only can this be done, but uneven wear can also be prevented.

In the above embodiments, the case where the device of the present invention was implemented in a DOHC type engine was explained, but it goes without saying that this can also be implemented in a 5OHC type engine. One end of a cam follower that is interlocked with the cam is connected.

C1 Effects of the Invention As is clear from the above embodiments, according to the present invention, in a valve train for an internal combustion engine, a pair of slipper parts arranged in parallel with a gap are integrally connected. A valve lifter is constituted by the sliding guide part, and a slipper surface is formed on the upper surface of the pair of slipper parts to which a valve actuating member such as a valve operating cam comes into pressure contact, and a slipper surface is formed on the lower surface of the slipper surface to which a valve operating member such as a valve operating cam comes into pressure contact. An engagement hole that engages with the upper end is formed, and a sliding surface that slides into contact with a guide receiving surface provided on the cylinder head is formed on the sliding guide part, so that a single valve lifter can be used in the same manner. By sharing a pair of poppet valves with 100% capacity, and in particular by sharing their sliding guide, it is possible to significantly reduce the weight of the valve, and as a result, the reciprocating mass of the valve mechanism is reduced and the engine In particular, it can contribute to improving the performance of high-speed engines.

Furthermore, the number of parts of the valve mechanism is reduced, and costs can be reduced.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a vertical cross-sectional view of an engine body equipped with the device of the present invention taken along the line 1-1 in FIG. 2, and FIG. 3 is a cross-sectional view taken along the line 1-111 of FIG. 2, and FIG. 4 is a perspective view of the valve lifter. L... Valve lifter 2... Cylinder head, 6... Intake boat, 7...
・Exhaust boat, 10...Intake valve as poppet valve,
DESCRIPTION OF SYMBOLS 11... Exhaust valve as a poppet valve, 21... Slipper part, 22... Sliding guide part, 23... Slipper surface, 24... Engagement hole, 26... Sliding surface, 27... Guide surface Fig. 4 Fig. 3 Fig. 2 Fig. I

Claims (1)

[Claims] In a valve train in an internal combustion engine for opening and closing a pair of poppet valves (10, (11)) having the same function of opening and closing intake or exhaust ports (6, 7) formed in a cylinder head (2), A pair of slipper parts (21, 21) arranged in parallel with an interval and their slipper parts (
a sliding guide part (22, 22) that integrally connects the parts (21, 21);
) constitutes a valve lifter (L), and the upper surfaces of the pair of slipper parts (21, 21) form slipper surfaces (23, 23) to which a valve operating member such as a valve operating cam comes into pressure contact, and the lower surface thereof. the pair of poppet valves (10, (11))
An engagement hole (24, 24) that engages with the upper end of the stem portion (10_z, (11_z)) is formed, and the sliding guide part (22, 22) has a guide provided in the cylinder head (2). Sliding surfaces (26, 2) that slide into contact with the receiving surfaces (27, 27)
6) A valve train for an internal combustion engine, comprising: