JPS5910324Y2 - Impact mitigation device when rocker arm moves - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shock absorbing device for a rocker arm moving type internal combustion engine when the rocker arm is moved.

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 (
(Japanese Patent Application No. 53-46702).

The present invention alleviates the impact when the rocker arm of an internal combustion engine that has a rocker arm movement mechanism, such as the variable valve engine mentioned above, is moved, reduces the impact noise during movement, and improves the impact wear resistance of the movement mechanism. The purpose is to

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

FIG. 1 is a partial plan view of a variable valve engine according to the present invention, and only one cylinder of the valve train is shown.

The cylinder head 1 of the engine is provided with an intake valve 3 for controlling the intake of combustible air-fuel mixture into the engine combustion chamber (not shown) and an exhaust valve 5 for controlling the discharge of burned exhaust gas from the engine combustion chamber. There is.

The intake valve 3 and the exhaust valve 5 are opened and closed by rocker arms 13, 15 that are swingable around rocker shafts 9, 11 provided between the supports 7, respectively.

A camshaft 17 is rotatably supported in synchronization with the movement of a crankshaft (not shown) of the engine, and three cams, namely, a low speed cam 19 and a high speed cam 21 for the intake valve 3, and a cam 23 for the exhaust valve 5 are stopped. It is worn.

The rocker arm 13 for opening and closing the intake valve 3 is connected to its rocker shaft 9.
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 is moved in the axial direction by a moving mechanism provided inside the engine. , for example, opened and closed by valve lift and valve timing.

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

As described above, in order to move the rocker arm 13 along the rocker axis, the movement is performed in a short time in the common base circle of the low speed cam 19 and the high speed cam 21, and
Rocker arm 13 and low and high speed cams 19.
It is necessary to prevent wear and damage to the rocker arm 21, and therefore the moving speed of the rocker arm 13 is considerably high, for example, 1 to 2 m/sec.

As a result, when the rocker arm 13 moves, the rocker arm 13 collides with the support 7 that supports the rocker shaft 9, causing noise and wear of the rocker arm 13 or the support 7.

The present invention is aimed at alleviating the impact caused by the collision during movement of the rocker arm. In the first embodiment, as shown in FIG.
The shape of a is used as an oil damper chamber.

In another embodiment of the present invention, as shown in FIG.
3a is used as an oil damper chamber.

In the above-described variable valve engine, lubricating oil is supplied to the valve train to lubricate it like a normal engine, and the rocker arm 13 and rocker shaft 9 are also coated with lubricating oil.

If the rocker arm 13 is moved in this state, the second
In the embodiment shown in the figure, the lubricating oil collected by the movement of the rocker arm 13 is added to the lubricating oil already present in the groove 7a of the support 7, and the groove 7a, that is, the oil damper chamber, is filled with lubricating oil. .

Further, in the embodiment shown in FIG. 3, as the rocker arm 13 moves, the groove 13a of the rocker arm 13, that is, the oil damper chamber, is filled with lubricating oil.

As a result, when the rocker arm 13 approaches the supports 1 and 7, the impact on the rocker arm is greatly alleviated by the damper effect of the oil damper chamber, that is, the grooves 7a and 13a, reducing impact noise and reducing the impact on the rocker arm 13 and the support. 7 wear is prevented.

Note that the groove 7a or 1 is formed on the side surface of the rocker arm 13 or the side surface of the support 7 opposite to the groove 7a of the support 7 forming the damper chamber or the groove 13a of the rocker arm 13.
3a may be formed with a protrusion (not shown) that fits into the damper to enhance the damping effect.

[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 Fig. 3 corresponds to Fig. 2 of another embodiment of the present invention. This is a diagram. 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, 7a... Annular groove of support, 13a... Annular groove of rocker arm.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. In a variable valve engine in which a rocker arm that opens and closes an engine opening/closing valve is movable between rocker shaft supports and along the rocker shaft, A shock mitigation device for rocker arm movement, featuring an oil damper mechanism. 2. A shock absorbing device during rocker arm movement according to claim 1, wherein the oil damper mechanism is formed by forming an annular oil damper chamber surrounding the rocker shaft on the support surface. 3. The shock absorbing device during movement of the rocker arm according to claim 1, wherein the oil damper mechanism is formed by forming an annular oil damper chamber surrounding the rocker shaft on the side surface of the rocker arm.