JPS6220646Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a push rod used in a valve mechanism of an internal combustion engine.

Conventional push rods were made of metal pipe material, which was superior in terms of strength, but was also extremely heavy, which increased the inertia of the valve train, making it difficult to jump or bounce as the engine ran at higher speeds. It had the disadvantage of increasing the

For this reason, the rod body is made of a fiber-reinforced resin material as in the push rod shown in JP-A No. 54-113713, and the rod end (end ) has been proposed using a ceramic material to reduce weight without sacrificing wear resistance, thereby reducing the inertia of the valve train, but in both cases the rod body and rod end are Since either of them is made of metal, there is a problem in that the above-mentioned weight reduction is not necessarily sufficient.

Further, in Japanese Patent Application Laid-Open No. 55-75977, a ceramic member and a metal member are combined via a heat insulating elastic body, but the end of the ceramic member is connected to the concave end of the metal member. Since the combined body is fitted to the part via the heat insulating elastic body, there is a risk that the combined body will expand in the radial direction, thereby increasing the weight.

The present invention was devised in view of the above-mentioned drawbacks, and prevents expansion in the radial direction at the fitting portion of the rod body and rod end, without impairing the wear resistance of the rod end and the strength of the rod body. The aim is to provide a push rod that is lightweight, thereby reducing the inertia of the valve train and reducing the occurrence of jumps and bounces.
The gist of this is a push rod in which a rod body made of carbon fiber reinforced resin and a rod end made of ceramic are brought into contact with each other, and a metal pipe attached to the inner peripheral surface of an elastic member is fitted to the outer periphery of the abutting part. This will be explained with reference to the diagram.

1 is a push rod body with high strength,
Constructed from carbon fiber reinforced resin material with high elastic modulus.

Reference numerals 2 and 3 denote rod ends having sliding portions 21 and 31 formed in arc-shaped concave portions and convex portions, respectively, and the shaft portions 22 and 32 have stepped portions 23 and 33 for fitting the metal pipe 4 thereto. is formed.

The metal pipe 4 has an elastic member 5 made of hard rubber or the like attached to its inner peripheral surface by baking or gluing.
It is constructed as a pipe consisting of two layers: a metal outer layer and an elastic inner layer.

Then, this metal pipe 4 is fitted onto the outer periphery of the joint between the end surfaces of the ends 11 and 12 of the rod body and the rear surfaces of the rod ends 2 and 3, and the fitting surfaces are bonded with adhesive. It is.

The push rod constructed as described above has the rod main body 1 excluding the rod ends 2 and 3 made of carbon fiber reinforced resin material having high strength and high modulus of elasticity. The weight can be reduced without deteriorating the strength, and the inertia of the valve train can be reduced.
It is possible to reduce the occurrence of jumps and bounces that occur as the engine speeds up as described above.

In addition, the rod body 1 and the rod ends 2 and 3 are brought into contact with each other, and the metal pipe 4 having the elastic member 5 attached to the inner peripheral surface is fitted to the outer periphery of the abutting portion. , 3 can be prevented from expanding in the radial direction, thereby reducing the weight.

Therefore, the inertia force of the valve train can be further reduced, and the effect of reducing the jump and bounce can be further improved.

Furthermore, since the elastic member 5 is attached to the inner peripheral surface of the metal pipe 4 that joins the abutting portions of the rod body 1 and the rod ends 2 and 3, even if thermal expansion occurs in the rod body 1, it will be absorbed by the elastic member 5. Since it is relaxed, the rod ends 2 and 3, which are made of ceramic material with an extremely small coefficient of thermal expansion, will not be damaged.

In addition, since the rod ends 2 and 3 are made of ceramic material and have excellent wear resistance, the sliding parts 21 and 31 where each rod end 2 and 3 slides on the rocker arm and cam, which are related parts of the valve mechanism.
This has the effect of improving the durability of.

As described above, the push rod according to the present invention is made by abutting a rod body made of carbon fiber reinforced resin and a rod end made of ceramic, and fitting a metal pipe attached to the inner circumferential surface of an elastic member to the outer periphery of the abutting part. It is possible to prevent the rod main body and the rod end from expanding in the radial direction, thereby reducing the weight of the push rod.

Therefore, by making the rod body made of carbon fiber reinforced resin and the rod end made of ceramic, the weight of the push rod can be further reduced, the inertia of the valve train can be reduced, and the inertia of the valve train can be reduced, making it easier to use as the engine speeds up. This has the effect of reducing the occurrence of jumps and bounces.

Further, since an elastic member is attached to the inner circumferential surface of the metal pipe that joins the abutting portion of the rod body and the rod end, even if thermal expansion occurs in the rod body, it is absorbed and alleviated by the elastic member. Since no heat load is applied to the ceramic rod end, which has an extremely small coefficient of thermal expansion,
This has the effect of preventing that damage.

[Brief explanation of the drawing]

Figure 1 is a front view showing an embodiment of the present invention; Figure 2 is a front view showing an embodiment of the present invention;
FIG. 3 is a partially enlarged longitudinal sectional view showing the main parts of the same embodiment. 1... Rod body, 2, 3... Rod end,
4... Metal pipe, 5... Elastic member, 21, 31
...The rubbing part.

Claims (1)

[Scope of utility model registration request] This is a push rod made by mating a rod body made of carbon fiber reinforced resin and a rod end made of ceramic, and fitting a metal pipe with an elastic member attached to the inner circumference around the outer periphery of the butt part.