JPH0332726Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a valve train for an internal combustion engine.

2. Description of the Related Art Conventionally, in order to improve the work efficiency of internal combustion engine maintenance, a valve train has been used in which a unit in which a rocker arm shaft and a rocker arm are assembled in a casing is detachably attached to a cylinder head. However, in this valve train,
When removed from the cylinder head, the rocker arm can freely rotate and fall due to its own weight, so the rocker arm may suddenly rotate and fall during maintenance, causing its tip to collide with the surface of a surface plate, etc. There is a problem with it being damaged.

This invention was made in view of the above, and its purpose is to provide a valve train for an internal combustion engine in which the rocker arm does not rotate and fall as described above even when the valve train is removed from the cylinder head. There is a particular thing.

The valve train for an internal combustion engine of this invention, which meets the above objectives, has a casing that is detachable from the cylinder head,
In a valve operating system for an internal combustion engine having a rocker arm shaft installed in the casing and a rocker arm rotatably supported on the rocker arm shaft, the rocker arm is located at a position outside the operating range of the rocker arm in the casing. The device is characterized by being provided with a stopper to prevent the rotation and fall of the device.

Hereinafter, specific embodiments of this invention will be described in detail with reference to the drawings.

A first embodiment of this invention is shown in FIGS. 1 and 2, and this valve train has a cylindrical casing 1.
and a rocker arm shaft 4 installed within this casing 1 between its longitudinal side walls 2 and 3;
It has a rocker arm 5 whose midway portion is pivotally supported by the rocker arm shaft 4. This valve train can be mounted on the cylinder head 7 by inserting bolts 6 into through holes provided in the casing 1 and tightening the bolts 6. Also, when removing for maintenance etc. This is done by loosening 6.

Adjustment bolts 8 and 9 are attached to both ends of the rocker arm 5, and the adjustment bolt 8 at one end contacts the upper end of a push rod 10 that is reciprocated by a camshaft and a tappet (not shown). are doing. Further, an adjustment bolt 9 provided at the other end of the rocker arm 5 is in contact with the valve stem head of the air supply or exhaust valve 11. Therefore, as the push rod 10 reciprocates in the vertical direction, the locker arm 5 reciprocates,
As a result, the valve stem reciprocates in the vertical direction to open and close the valve 11. Note that 12 is a valve spring for urging the valve upward, and 13 is a seat plate for receiving and supporting the spring force.

A rod-shaped stopper 14 is further installed within the casing 1 between the longitudinal side walls 2 and 3 thereof. This stopper 14 is as shown in the figure.
Of both ends of the rocker arm 5, the end that rotates and falls downward because its own weight is large, is a position below the rocker arm 5, and is also outside the normal operating range of the rocker arm 5. It is located in

By providing the stopper 14 in the casing 1 in this way, even if the rocker arm 5 tries to rotate due to its own weight when the entire valve train is removed from the cylinder head 7, its lower part abuts against the stopper 14 and is supported. Therefore, further rotation and fall can be prevented.

FIG. 3 shows a second embodiment of the valve train of this invention, which consists of two rocker arms 5,
15, the upper end of the second rocker arm 15 is engaged with the lower end of the first rocker arm 5, the rotation of the first rocker arm 5 is transmitted to the second rocker arm 15, and the two air supply or exhaust gases are simultaneously connected. The purpose is to open and close the valves 11a and 11b. In order to prevent both the first and second rocker arms 5 and 15 from rotating and falling, there is also a position inside the casing 1 of this valve train below the second rocker arm 15, and also during normal operation of the rocker arm 15. A stopper 14 is provided at a position that is outside the range.

FIG. 4 shows a third embodiment of this invention, which is different from the stopper 1 in the second embodiment.
The position of 4 has been changed. That is, in this case, the stopper 14 is provided at a position above the rear end of the second rocker arm 15, and an engaging claw portion 16 that can engage with the stopper 14 is formed at the rear end of the second rocker arm 15. be.

In both the second and third embodiments, it is possible to prevent the rocker arms 5, 15 from rotating and falling when the valve train is removed from the cylinder head 7.

The embodiment of this invention has been explained above,
This invention is not limited to the above embodiments,
Of course, it can be implemented with various modifications. For example, the stopper 14 is not limited to the rod-like shape described above, but may be integrally formed with the casing 1 by casting or the like, and its position may be changed in various ways.

The valve train of this invention is constructed as described above, and therefore, even when the valve train is removed from the cylinder head for maintenance etc., the rocker arm will not rotate unexpectedly. Since it is possible to prevent the rocker arm from moving and falling, the tip of the rocker arm does not collide with the surface of a surface plate or the like and is damaged, which is extremely useful in practice.

[Brief explanation of the drawing]

Figures 1 and 2 show a first embodiment of this invention, Figure 1 is a vertical sectional view of the central part thereof, Figure 2 is a partially sectional plan view, and Figure 3 is a second embodiment of the invention. FIG. 4 is a central longitudinal sectional view showing the third embodiment. 1...Casing, 4...Rotsuka arm shaft,
5, 15...Lotsuka arm, 14...Stopspa.

Claims (1)

[Scope of utility model registration request] A casing that is removably attached to the cylinder head, a rocker arm shaft installed within this casing,
In a valve train for an internal combustion engine having a rocker arm rotatably supported on a rocker arm shaft, a stopper is provided in the casing at a position outside the operating range of the rocker arm to prevent the rocker arm from rotating and falling. A valve train for an internal combustion engine, characterized in that: