JPS606567Y2 - Impact mitigation device when rocker arm moves - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shock absorbing device when a rocker arm of an internal combustion engine is moved, which includes an axially movable rocker arm.

The present applicant first pivoted a rocker arm that opens and closes an on-off valve of an engine so as to be able to swing around a rocker shaft, and also made it movable along the rocker shaft. A camshaft that rotates in time is provided on the shaft, and a plurality of cams having different cam profiles are fixed adjacent to each other on the camshaft, and the rocker arm is moved to selectively open and close by one of the plurality of cams. proposed a variable valve engine characterized by opening and closing valves (
Special application 1970-4670).

The present invention alleviates the impact when the rocker arm moves in an internal combustion engine having a rocker arm moving mechanism, such as the variable valve engine mentioned above, reduces the impact noise during movement, and increases the impact wear resistance of the moving mechanism. In a variable valve engine, a rocker arm is pivotally attached to a rocker shaft so as to be swingable, and the rocker arm is movable in the axial direction between supports supporting the rocker shaft. between opposite sides of the support,
It is an object of the present invention to provide a shock absorbing device when a rocker arm moves, in which a spring member is attached to only one of the two side surfaces and is spaced apart from the other side surface.

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

In FIG. 1, which is a partial plan view of the variable valve engine according to the present invention, the valve train for the - cylinder is shown, and the cylinder head 1 of the engine is used to direct combustible air-fuel mixture to the combustion chamber (not shown) of the engine. The engine has an intake valve 3 that controls the intake of gas, and an exhaust valve 5 that controls the exhaust of burnt gas from the combustion chamber.

Rocker shafts 9 and 11 are fixedly installed between the fixedly installed supports 7, and rocker arms 13 and 15 for opening and closing the intake valve 3 and the exhaust valve 5 are pivotably pivoted to the rocker shafts 9 and 11, respectively. There is.

The camshaft 17 is rotatable in synchronization with the movement of the engine crankshaft (not shown), and is provided with a low-speed cam 19 and a high-speed cam 21 for opening and closing the intake valve 3, and a cam 2 for opening and closing the exhaust valve.
3 cams are fixed.

A rocker arm moving mechanism (not shown) is provided inside the rocker shaft 9, and a rocker arm 1 for opening and closing the intake valve 3 is provided inside the rocker shaft 9.
3 can be moved along the rocker axis 9.

As a result, the rocker arm 13 is selectively opened and closed by the low-speed cam 19 or the high-speed cam 21, and the intake valve 3
The valves are opened and closed under optimal valve conditions (valve lift, valve timing) depending on the engine operating conditions.

In this embodiment, the exhaust valve 5 is always opened and closed by one cam 23, but like the intake valve 3, it may be opened and closed by different cams depending on the operating state of the engine.

When the rocker arm 13 is moved on the two cams 19.21 along the rocker shaft 9 as described above, the rocker arm 13 is moved along the rocker shaft 9 to prevent wear and damage to the rocker arm 13 and the low-speed and high-speed cams 19.21. 13 needs to be moved during a short period of time during which the cams 19.21 are in the common base circle of both cams 19.21.

Therefore, the moving speed of the rocker arm 13 is, for example, 1 to 2.
The speed is quite high at rrL/sec.

As a result, the rocker arm 13 collides with the rocker shaft support 7 during movement, resulting in noise generation and the rocker arm 13 or the support 7 being worn out.

In the embodiment shown in FIG. 1, an annular groove 7a surrounding the rocker shaft 9 is formed on the side surface of the support 7, as shown in FIG. A compression coil spring 25 having a large winding diameter is installed as the spring member of the present invention.

Therefore, at the end of the rocker arm movement, the rocker arm 13
presses the compression coil spring 25, so the shock when the rocker arm moves is alleviated, noise is reduced, and the rocker arm 1
3 and support 7 can be reduced.

The spring member of the present invention uses a disc spring 26 as shown in FIG. 3 in place of the compression coil spring 25 shown in FIG.
6 may be provided on the side surface of the support 7 so as to surround the rocker shaft 9.

Furthermore, the spring member of the present invention only needs to be provided between the support 7 and the rocker arm 13, and instead of being provided on the side of the support 7 as shown in FIGS. 13 may be provided.

In Fig. 4, an annular groove 13a surrounding the rocker shaft 9 is formed on the side surface of the rocker arm 13, and a compression coil spring 25 is installed in the groove 13a, and its end is fixed to the rocker arm to form the rocker arm. 13 Prevents it from coming off when moving.

In the present invention, the spring member installed between the rocker arm side surface and the support side surface supporting the rocker arm shaft is arranged so as to be engaged with only one of the two side surfaces and spaced apart from the other side surface. At the beginning of the movement of the rocker arm along the rocker arm axis, the movement is free without being subject to any restrictions by the spring member, and only at the end of the movement, the spring member comes into contact with the other side surface and provides a buffering effect. It will demonstrate the

Furthermore, if the spring member is made strong enough so that the side surface of the rocker arm and the side surface of the support come into contact at the end of the movement of the rocker arm, it is possible to position the end of movement of the rocker arm. It is also possible to maintain the optimal state of contact between the tip and the cam.

[Brief explanation of the drawing]

Fig. 1 is a partial plan view of a variable valve engine according to the present invention, Fig. 2 is a partial sectional view of the main part of Fig. 1, and Figs. FIG. 1... Cylinder head, 3... Intake valve, 5... Exhaust valve, 7... Support, 9, 11... Rocker shaft,
13.15... Rocker arm, 17... Camshaft,
19.21, 23...cam, 25...compression coil spring, 26...disc spring.

Claims (1)

[Claims for Utility Model Registration] 1. A variable valve engine in which a rocker arm is pivotably attached to a rocker shaft and the rocker arm is movable in the axial direction between supports supporting the rocker shaft. A shock absorbing device during movement of a rocker arm, characterized in that a spring member is attached between opposing sides of the rocker arm and the support, the spring member being engaged with only one of the two sides and spaced apart from the other side. 2. A shock absorbing device during rocker arm movement according to claim 1, wherein the spring member is a disc spring. 3. A shock absorbing device during rocker arm movement according to claim 1, wherein the spring member is a compression coil spring.