JPH0315763Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improved rocker arm used in an internal combustion engine, and more specifically, it proposes a rocker arm structure that is lighter in weight and has greater 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. The rocker arm, which is supported by a shaft passing through the shaft hole 1 and repeatedly oscillates about the shaft, is made of metal materials such as cast iron or aluminum and has a considerable weight. To be there,
Particularly during high-speed operation, a large inertial force is generated, which not only causes energy loss but also causes noise generation problems. For this reason, as well, previously, Utility Application No. 57-60034 (Utility Application No. 58-162202)
or Utility Application No. 57-29765 (Utility Application No. 58-132109)
As shown in the microfilm shown in Figure 1, the entire Rocker arm is made of synthetic resin to reduce weight, and reinforcing members are bonded or embedded in each part, but the former only reinforces the sliding parts. The parts are joined together, and the latter has separate reinforcing members embedded in the rib part and boss part, respectively, and when tensile stress is applied to the rocker arm during operation, distortion occurs in the unreinforced part. , Therefore, there is a problem that the reinforcing effect is not sufficiently compensated.

In view of the above points, the present invention was devised in order to solve the problems seen in the above-mentioned prior art. A rocker arm is formed entirely of synthetic resin, with a shaft hole provided at the center of the swing of both arms, and a female screw hole provided near the tip of the valve-side arm.A metal plate reinforcement is provided inside the rocker arm. The reinforcing member is provided at one end of a pair of flat plate portions that are substantially orthogonal to the center line of the shaft hole and substantially parallel to each other, and that substantially surrounds the female threaded hole. a U-shaped connecting portion; a sliding plate provided at the other end of the flat plate portion and exposed to the sliding portion of the valve side arm;
A through hole is provided in the flat plate part and is formed concentrically with the shaft hole.

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.

Further, the reinforcing member is made of a metal plate such as a steel plate or a brass plate, and is punched and bent using a press, and impregnated with an appropriate adhesive prior to molding of a synthetic resin material.

Below, the first to third parts of the Rotzker arm of the present invention will be described.
To explain the embodiment according to the drawings, first, the second
The figure shows a reinforcing member 4 according to a first embodiment, in which two flat plate portions 5, 5 facing each other are connected at a connecting portion 6 to form a planar shape into an elongated substantially U-shape, and the lower end of the reinforcing member 4 is formed. A rib 7 is bent outward over the entire line, and the longitudinal tip of the rib 7 is connected to sliding plates 8, 8 located on the sliding surface of the cam side arm 3 shown in FIG. has been done. This reinforcing member 4 is made by bending a metal plate with a large number of small holes (excluding the sliding plates 8, 8), and has a shaft hole 1, and has a shaft hole 1 in between. It is inserted into a main body made of synthetic resin material having a valve side arm 2 and a cam side arm 3,
At least the sliding plates 8, 8 are exposed on the surface of the main body (see FIG. 3). Through holes 11, 11 concentric with the shaft hole 1 are formed in the flat plate parts 5, 5.

The rocker arm having the above structure is made entirely of synthetic resin material, which makes it lightweight, and the reinforcing member 4 inserted into the rocker arm increases its strength. It becomes possible to increase the strength of the female threaded hole 10 with respect to the lock bolt drilled in the hole 2. In other words, this female screw hole 10
The periphery has a three-layer structure in which synthetic resin materials are arranged inside and outside of the connecting portion 6 of the reinforcing member 4, and the synthetic resin materials inside and outside are directly connected through a large number of small holes drilled in the connecting portion 6. Because of this structure, the female threaded hole 10 has great strength and can securely screw the lock bolt into the female threaded hole 10.

In the second embodiment shown in FIG. 4, ribs 9 are also bent over the entire length of the upper ends of the flat plate portions 5, 5 of the reinforcing member 4 of the first embodiment.

In a third embodiment shown in FIGS. 5 and 6, the reinforcing member 4 of the second embodiment, which is provided with upper and lower ribs 7 and 9, is divided into left and right halves.

The rocker arm of the present invention has the following effects due to the above structure and operation. That is, inside the rocker arm made of synthetic resin, there is a pair of flat plate portions that are approximately perpendicular to the center line of the shaft hole and approximately parallel to each other;
a substantially U-shaped connecting portion provided at one end of the flat plate portion and surrounding the female screw hole; a sliding plate provided at the other end of the flat plate portion and exposed to the sliding portion of the valve side arm; Since the entire rocker arm is reinforced by embedding a reinforcing member including a through hole provided in the flat plate part and formed concentrically with the shaft hole, the rocker arm has sufficient mechanical strength as a whole. The flat plate portion is disposed perpendicular to the center line of the shaft hole and parallel to the swinging direction of the arm, and has sufficient strength to prevent bending due to tensile stress caused by moments during operation.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a structural example of a rocker arm to which the present invention is applied, FIG. 2 is a perspective view of a reinforcing member used in the rocker arm according to the first embodiment of the present invention, and FIG. FIG. 4 is a perspective view of a reinforcing member used in a rocker arm according to a second embodiment of the present invention, and FIG. 5 is a partially cutaway perspective view of a rocker arm according to a third embodiment of the present invention. FIG. 6 is an exploded perspective view of a reinforcing member used in the present invention, and FIG. 6 is a plan view thereof. DESCRIPTION OF SYMBOLS 1... Shaft hole, 2... Valve side arm, 3... Cam side arm, 4... Reinforcement member, 5... Flat plate part, 6
...Connection part, 7, 9...Rib, 8...Sliding plate, 1
0...Female screw hole, 11 through hole.

Claims (1)

[Scope of utility model registration request] Comprising a valve side arm 2 and a cam side arm 3,
A shaft hole 1 is provided at the center of the swing of both the arms 2 and 3, and a female screw hole 10 is provided near the tip of the valve side arm 2, and the rocker arm is entirely molded from synthetic resin. A reinforcing member 4 made of a metal plate is buried inside, and the reinforcing member 4 has a pair of flat plate parts 5, 5 that are substantially orthogonal to the center line of the shaft hole 1 and substantially parallel to each other; 5, a substantially U-shaped connecting portion 6 surrounding the female screw hole 10, and the flat plate portions 5, 5.
sliding plates 8, 8 provided at the other end and exposed to the sliding portion of the valve side arm 3; and the flat plate portions 5, 5.
A rocker arm characterized by comprising through holes 11, 11, which are provided in the shaft hole 1 and are formed concentrically with the shaft hole 1.