JPH0310324Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a rocker arm used in an internal combustion engine, and more specifically, it proposes a rocker arm structure that is lightweight and has great strength.

A rocker arm used as an element of a valve opening/closing means of an internal combustion engine has a valve side arm 2 and a cam side arm 3 extending from a shaft hole 1 in mutually opposite directions, as shown in FIG. It is supported by a shaft 1 passing through a shaft hole 1 and repeatedly oscillates around the shaft. Conventionally used rocker arms are made of metal materials such as cast iron and aluminum and weigh considerably. Because of this, especially during high-speed operation, a large inertial force is generated, which not only causes energy loss but also causes noise generation problems.

This invention aims to reduce weight by using a synthetic resin material as the material for the Rotsuker arm, and it is also made of a metal plate with many small holes, and a reinforcing member is inserted that connects the valve side arm to the cam side arm. By making the reinforcing member bear the tensile stress caused by the bending moment that occurs during operation, it is made to have no inferiority in terms of strength compared to conventional rocker arms made of cast iron, aluminum alloy, etc. It is something.

As the material used for molding, synthetic resin materials with heat resistance and oil resistance are suitable, and phenol resins, polyimide resins, polyester resins, diallyl phthalate resins, epoxy resins, silicone resins, etc. can be used, and glass It is more preferable to disperse short fibers, potassium titanate whiskers, asbestos powder, etc. alone or in combination of two or more, as this will strengthen the mechanical rigidity.

For reinforcing members, metal plates such as steel plates and brass plates are used.
Prior to molding the synthetic resin material, it is punched and bent by press processing, and impregnated with an appropriate adhesive.

Embodiments of the present invention will be described below with reference to the drawings. In the embodiment shown in FIG. 2, a metal plate with a large number of small holes is bent to extend from the sliding surface 5 of the cam-side arm 3 to the lower surface of the valve-side arm 2, as shown in detail in FIG. A reinforcing member 7 formed by processing is arranged.

In the other embodiments shown in FIGS. 3 and 4, the reinforcing member 7 has two side plates 9 facing each other substantially perpendicular to the center line of the shaft hole 1, and a sliding surface 5 side of the cam side arm 3. The sliding plate 10 is located at the side plate 10 and connects the side plate 9.

As mentioned above, the main body of the Rocker arm is molded from a synthetic resin material that has a lower specific gravity than cast iron, and a reinforcing member made of a metal plate is inserted. Compared to this, we have obtained a Rocker arm that is approximately 30 to 40% lighter in weight and comparable in strength to a metal one.

[Brief explanation of the drawing]

Fig. 1 is a side view showing a structural example of a rocker arm to which the present invention is applied, Fig. 2 is a sectional view showing an embodiment of the invention, and Fig. 3 is a reinforcing member in the embodiment of Fig. 2. FIG. 4 is a cross-sectional view of a cam-side arm of another embodiment of the present invention, and FIG. 5 is a perspective view showing the shape of a reinforcing member in the embodiment of FIG. 4. DESCRIPTION OF SYMBOLS 1... Shaft hole, 2... Valve side arm, 3... Cam side arm, 5... Sliding surface, 7... Reinforcement member, 9
...Side plate, 10...Sliding plate.

Claims (1)

[Claims for Utility Model Registration] 1. A Rocker arm made of a synthetic resin material, into which a reinforcing member made of a metal plate with a number of small holes extending from the valve side arm to the cam side arm is inserted. 2. The rocker arm according to claim 1, wherein the reinforcing members are arranged perpendicularly to the central axis of the shaft hole. 3. The rocker arm according to claim 1, wherein the reinforcing members are arranged parallel to the central axis of the shaft hole and along the tensile stress generation surface.