JPS6013906A - O.h.c. type valve mechanism of internal-combustion engine - Google Patents

Abstract

PURPOSE:To make it possible to dispose an ignition plug at the axial position of a cylinder and to lighten the valve mechanism by disposing one cam shaft, which opens or closes both of a suction valve and an exhaust valve, in the proximity of the one valve. CONSTITUTION:An ignition plug 14 is disposed at a position of the cylinder axis Ac and a suction valve 10 and an exhaust valve 11 are provided with a plane including the axis pinched therebetween. The cam shaft 21 which provides an opening and closing force to both valves 10 and 11 is disposed in the proximity of the suction valve 10, and the suction valve 10 is actuated through a first can follower 25. The exhaust valve 11 is actuated through a second cam follower 31 and a push rod 34 which are pivotally supported on a shaft 28 and a locker arm 33 which is pivotally supported on a shaft 29. Since the cam shaft 21 is drawn near to one side, the ignition plug can be disposed on the cylinder axis Ac, and hence one cam shaft 21 suffices. Accordingly, it is possible to simplify and lighten the valve mechanism.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides O, H, and , related to type valve gears.

In the 0, HoC, type valve train, one camshaft is disposed approximately along a plane including the axis of the cylinder.

A 0°H, C type valve train and two camshafts for intake and exhaust are arranged close to the intake and exhaust valves, respectively. 0
．． There are H and C0 type valve train systems, but with the former, it is extremely difficult to place the spark plug near the cylinder axis, where conditions are favorable for combustion, due to interference with the camshaft. The structure of the timing transmission device is simple, and in particular, only one heavy camshaft is required, which is advantageous in reducing the weight of the engine.In contrast, in the latter case, the ignition occurs near the cylinder axis without interference from both camshafts. Although it is possible to improve the output performance of the engine by arranging a stopper, this inevitably complicates the structure of the timing transmission and increases the weight of the engine, so each method has its advantages and disadvantages.

The present invention provides a valve train that incorporates only the advantages of the two types of valve train described above, and which allows the ignition plug to be placed near the cylinder axis despite having only one camshaft. The purpose is to

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. The internal combustion engine shown in FIG.
It has C2. Since the structures of both cylinder rows C, , C2 are symmetrical, only the left cylinder row C1 will be described below.

A cylinder head 3 is superimposed and bonded to the upper surface of a cylinder block 2 having a cylinder 1 via a gasket 4. A piston 5 is slidably fitted into the cylinder 1, and a combustion chamber 6 is recessed in the bottom surface of the cylinder head 3 facing the piston 5.

The ceiling surface 7 of the combustion chamber 6 consists of two ceiling slopes 7a and 7h that descend on both sides from the ridge line passing on or near the axis Ac of the cylinder 1, and one ceiling slope 7a has a pair of intake ports. 8, 8, and a pair of exhaust ports 9, 9 are opened in the other ceiling slope 7h, and are lined up along the ridgeline. Each pair of intake valves 10.10 are configured to open and close the intake ports 8, 8 and exhaust port 99.
and exhaust valves 11.11 are slidably supported on valve guides 12.12 and 13.13 provided in the cylinder head 3, respectively. At that time, the intake valve 10.10
Exhaust valve 11. is located on the valley V side between both cylinder rows C, , C2.
11 is arranged on the opposite side thereof, and both valves 10, 11 are tilted in mutually opposite directions with respect to the plane P.

As shown in FIGS. 2 and 4, an ignition plug 14 with an electrode facing the combustion chamber 6 is screwed onto the cylinder head 3. It is arranged approximately along the cylinder axis Ac so that it is surrounded by.

A valve chamber 17 is formed on the upper surface of the cylinder head 3 by sequentially overlapping and bonding a bearing stand 15 and a head cover 16.
The chamber 17 has the intake valves io, io and the exhaust valves 11.11.
A valve train 18 of the present invention is provided to provide an opening/closing operation to the valve.
It has the following structure.

The intake valve 10.10 and the exhaust valve 11.11 are respectively fitted with valve springs 19, 19 and 20.20 which urge them toward the closing side.

Approximately directly above the intake valve 10.10, and therefore at a position closer to the valley V side than the cylinder axis Ac, there is a single camshaft that is interlocked with the crankshaft (both not shown) via a timing transmission. 21 is disposed parallel to the plane P, and the journal 21j of the shaft 21 is connected to the bearing pedestal 15 and the journal 21j thereof.
It is rotatably held between the bearing caps 24 which are connected at 2.23.

Placing the camshaft 21 on one side toward the valley V side in this manner is effective in reducing the maximum outer dimension of both cylinder rows C0, C as much as possible, thereby reducing the size of the V-type machine.

As shown in FIG. 3, the camshaft 21 has a pair of intake cams 21 i corresponding to the intake valve 1010 and the exhaust valves 11, 11.
, 21i and exhaust cams 21e, 21e, the intake cams 211, 21'l are arranged adjacent to the journal 21 on both sides thereof, and the exhaust cams 21C, 21g are further arranged on both row sides thereof.

A pair of first cam followers 25.25 are interposed between the intake cams 21Z, 21i and the head of the intake valve 10.10. This first cam follower 25.25 is equipped with an adjusting bolt 26 at each base end, and a spherical end 26a at the tip of the adjusting bolt 26 rotates into a spherical recess 27a of a support bolt 27 screwed onto the cylinder head 3. can be freely engaged.

The first and second support shafts 28 and 29 are fixed to the bearing stand 15 by pins 22 and 30, respectively, and at this time both support shafts 28.
29 are arranged between the intake and exhaust valves 10, 10; 1111, sufficiently separated from each other across the axis Ap of the spark plug 14, and parallel to the camshaft 21. And intake valve 10.1
The first support shaft 28 close to 0 is the intake cam 21 i , 21
a pair of second cam followers 31 .
31 is swingably supported, and a second valve near the exhaust valve 11.
The support shaft 29 swingably supports a pair of bell crank type rocker arms 33, 33 which engage the heads of the exhaust valves 11, 1.1 via adjustment bolts 32, respectively. This 1-
42 cam follower 31.31 and rocker arm 33.33
A pair of bushing rods 34 and 34 are respectively interposed between the opposing surfaces.

A tool hole 35 used for attaching and detaching the spark plug 14 is provided with the two support shafts 28, 29 and the bush rods 34, 3.
40 In the area surrounded by four cylinder head 30 spark plug 1
The part of the tool hole 35 that extends through the valve train chamber 17 is formed by a partition cylinder 36 interposed between the helad cover 16 and the bearing stand 15. . In this case, both support shafts 28, 29 are spaced sufficiently apart from each other, and both bush rods 34° 3
4 is engaged with the exhaust cams 21g and 21e located on the outer side of the periphery to ensure a wide gap therebetween, so that the tool hole 3
5 can be formed to have a sufficient size so that the spark plug 14 can be easily attached and detached.

Next, the operation of this embodiment will be explained. During operation of the engine, the camshaft 21 is rotationally driven by the crankshaft via a timing transmission (not shown). Then, when the intake stroke of the piston 5 is started, the intake cam 21L.

The peaks of 21 O swing the first cam followers 25.25 toward the intake valves 10.10, so that the intake valves 10.10 open against the elastic force of the valve springs 19, 19. However, at the end of the intake stroke, the intake cams 21i, 21
Since the peak of i passes the first cam follower 25.25, the intake valve 10.10 is closed by the elastic force of the valve springs 19,19. During this time, an air-fuel mixture is drawn into the combustion chamber 6 from an air-fuel mixture generating device such as a carburetor (not shown) through the intake boats 8, 8.

When the piston 5 approaches the end of its compression stroke (and the spark discharge from the spark plug 14 ignites the compressed gas in the combustion chamber 6, the piston 5 moves to the expansion stroke. At this time, the spark plug 14 moves toward the cylinder axis AC or Since they are located close to each other, the flame propagation distance from the ignition point to each peripheral edge of the combustion chamber 6 is approximately equal, so that the combustion time is shortened to the minimum and a high output is produced.

When the exhaust stroke of the piston 5 is started, the exhaust cam 21C
Since the peak of 221e swings the second cam follower 31.31 towards the bushing rod 34.34, the bushing rod 34.34 is displaced and swings the rocker arm 33.33 towards the exhaust valve 11.11. Exhaust valve 1
1.11 opens the valve against the elastic force of the valve spring 20.20,
At the end of the exhaust stroke, the peaks of the exhaust cams 21e, 21e pass the second cam followers 31.31, so the exhaust valves 11, 11 are closed by the elastic force of the valve springs 20.20. During this time, exhaust gas is discharged from the combustion chamber 6 to the exhaust port 9.9.

The ignition plug 14 is attached and detached by inserting a special tool into the tool hole 35, fitting it onto the head of the ignition plug 14, and rotating the tool.

Incidentally, in the present invention, contrary to the above embodiment, the camshaft 21 and the first camshaft 21 and the first . 2nd cam follower 25.31 to exhaust valve 1
1 side, and the rocker arm 33 can be arranged on the intake valve 10 side, and the exhaust cams 21e, 21
e adjacent to both sides of the journal 21, and the intake cam 21
i, 21i can also be arranged on the outer side of the periphery. Furthermore, the number of intake and exhaust valves used is not limited (for example, the present invention can be applied to one intake valve and one exhaust valve each).

As described above, according to the present invention, 0. An Il, C type valve operating device is installed between a camshaft disposed close to one of the intake and exhaust valves, and the one valve and the camshaft to open the camshaft. a first cam follower for transmitting force to the one valve; a first support shaft disposed proximate to the one valve; and a first cam follower disposed proximate to the other of the intake and exhaust valves. two support shafts, a second cam follower that is swingably supported by the first support shaft and engages with the camshaft, a rocker arm that engages with the other valve, and between the second cam follower and the rocker arm. Since the bushing rod is interposed and transmits the valve opening force transmitted from the camshaft to the second cam follower to the other valve via the rocker arm,
Even though a single camshaft is used, it does not interfere with the camshaft (the spark plug can be placed near the cylinder axis,
Therefore, the timing transmission device can be easily configured, making the engine more compact and contributing to its weight reduction.Furthermore, it is possible to obtain a good combustion state of the air-fuel mixture and improve output performance. can.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional front view of the main parts of an internal combustion engine according to an embodiment of the present invention, Fig. 2 is a bottom view of the cylinder head in Fig. 1, and Fig. 3 is a cylinder head shown with the head cover removed. 1
FIG. 4 is an enlarged plan view of the figure, and FIG. 4 is a sectional view taken along the line IV--IV of FIG. Ac...Cylinder axis, Ap...Ignition plug axis, P
... Plane including cylinder axis 1 ... Cylinder, 10 ... Intake valve, 11 ... Exhaust valve, 14 ... Spark plug, 18 ... Valve train, 21 ...
・Camshaft, 25...First cam follower, 28...First support shaft, 29...Second support shaft, 31...Second cam follower, 33...Rocker arm, 34...Butsch rod patent Applicant Honda Motor Co., Ltd. Figure 4' Figure 2 Procedural Amendment (Bin) 1. Indication of the incident 1982 Patent Application No. 122199 2 Name of the invention 0.0 of an internal combustion engine. H, C, type valve train 3, relationship with the case of the person making the amendment Name of patent applicant (532) Honda Motor Co., Ltd. 4, Agent
Person 〒105 Telephone Tokyo 434-4151 5゜Date of amendment order October 1, 1982 (Shipping date: October 25, 1982)
6) Subject of correction

Claims (1)

[Claims] (1) A 00H0C0 type valve train for an internal combustion engine, in which an ignition plug is disposed approximately along the axis of a cylinder, and an intake valve and an exhaust valve are disposed across a plane including the axis, and the intake and exhaust valves are a camshaft disposed close to one of the valves;
a first cam follower interposed between the one valve and the camshaft to transmit the valve opening force of the camshaft to the one valve; and a first support shaft disposed close to the one valve. and said sucking;
a second support shaft disposed close to the other valve of the exhaust valve; a second cam follower swingably supported by the first support shaft and engaged with the camshaft; and the second support shaft. a rocker arm supported by a rocker arm that engages the other valve; and a rocker arm that is interposed between the second cam follower and the rocker arm and transmits the valve opening force transmitted from the camshaft to the second cam follower through the rocker arm. 0, H0C6 type valve train consisting of a bushing rod that transmits to the other valve. (2. In the item described in claim (1),
0, H0C0 type valve operating system for an internal combustion engine, wherein the first and second support shafts are arranged to be spaced apart from each other across the axis of the spark plug.