JPS6347604Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved end fitting structure of a valve drive push rod for an internal combustion engine, particularly having an arcuate head engaging surface projecting outward.

In recent years, in relation to the trend toward higher rotation speeds in automobile engines due to the increase in engine horsepower, the push rod itself also has oil passed through its interior to prevent contact with the mating tappet member and the adjusting screw member on the rocker arm side. Mechanisms for lubricating mutual abutting and engaging parts have come to be widely used. However, as shown in FIGS. 4, 5, and 6, the conventional valve train push rod has a metal tube shaft body 1.
An end fitting 2 having an outwardly protruding, curved, arc-shaped head engaging surface, which is fixed to at least one of the circumferences of both cut ends of the end fitting 14 by resistance welding, is inserted through the oil passage hole 13 in the shaft core. It was configured with a set state.

Therefore, most of them are about 1.0m/m to 2.0m/m
10.0m/m to 10.0m/m
The 25.0m/m long shaft penetrates through the structure, making it extremely difficult to drill holes with a drill, which often results in defective products due to drill breakage during processing, and repeated drilling. This had the problem of causing wear and tear due to replacement, which forced a significant drop in productivity.

The purpose of the present invention is to provide a push rod for a valve train of an internal combustion engine which solves the above-mentioned problems extremely effectively with a simple structure.The push rod for a valve train of an internal combustion engine according to the present invention , an end fitting having an outwardly protruding arcuate head engaging surface is attached to at least one of the circumferences of both cut ends of the metal tube shaft body, and the back surface of the head is coaxially fixed by electric resistance welding or the like. In the push-rod structure, the oil passage hole in the shaft core is not drilled, but the oil passage groove is drilled in advance along the circumferential surface including the engagement surface in the longitudinal direction passing through the shaft core. The end fitting is fixed with the oil passage groove positioned in the axial direction of the metal tube shaft, thereby making mass production possible.

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 to 3.
The metal tube shaft body 1 consisting of m has an arcuate head engaging surface projecting outward on at least one of the circumferences of both cut ends thereof, and the head engaging surface in the longitudinal direction passing through the shaft center. An oil passage groove 3 is formed in advance along the circumferential surface including the engagement surface.
The end fitting 2 is constructed by fixing 4 the back surface of the end fitting 2 by electric resistance welding with the oil passage groove positioned in the axial direction of the metal tube shaft body 1.

As described above, according to the present invention, the end fitting 2 is configured to be used with the oil passage groove 3 provided along the circumferential surface including the head engagement surface in the longitudinal direction passing through the axis. This structure makes it extremely simple to perform cutting on the peripheral surface, and at the same time, since the cutting tool is used as a cutting tool during this process, there is no need to worry about breakage as with drills, and it also reduces the number of defective products and improves cutting efficiency. It is possible to reduce tool wear and tear, and it is also possible to easily form the oil passage groove 3 by pressing from the outside at the same time as forming the end fitting 2 alone, without using this cutting. It is extremely useful.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway side view of a push rod for a valve train of an internal combustion engine according to an embodiment of the present invention;
The figures are a single side view of one end fitting in Fig. 1, Fig. 3 is a plan view of Fig. 2, Fig. 4 is a partially cutaway side view showing a conventional example, and Fig. 5 is one side of Fig. 4. FIG. 6 is a side view of the end fitting alone, and FIG. 6 is a plan view of FIG. 5. 1... Metal tube shaft body, 2... End fitting, 3... Oil passage groove, 4... Fixed.

Claims (1)

[Scope of utility model registration request] An end fitting having an outwardly protruding, arcuate head engaging surface is attached to at least one of the circumferences of both cut ends of the metal tube shaft body, and the back surface of the head thereof is coaxially fixed by electrical resistance welding or the like. In the push rod structure, the end fitting 2 is provided with an oil passage groove 3 along the circumferential surface including the engagement surface in the longitudinal direction passing through the shaft center, and the oil passage groove 3 is attached to the metal tube shaft body. 1. A push rod for a valve train of an internal combustion engine, characterized in that the push rod is fixedly positioned in the axial direction of the engine.