JPS6174965A - Assembly cam shaft - Google Patents

Abstract

PURPOSE:To permit the strong connection by forming a concaved part onto the inner periphery of a cam piece and forming a projection part engaged with the concaved part in projection onto a hollow reinforced-plastic cam shaft which penetrates through the inner periphery of the cam piece. CONSTITUTION:A concaved part 4 is formed onto the inner periphery of a ring-shaped cam piece 3, and a projection part 5 engaged with the concaved part 4 is formed in projection by applying heat and internal pressure onto a filament-winding hollow reinforced-plastic cam shaft 2 which penetrates through the inner periphery of the cam piece. Said cam piece 3 is formed through selecting metal casting forging, sintering, and fiber-reinforced plastic. Therefore, long fiber reaches also in the projection part 5, and the cam shaft 2 and the cam piece 3 can be firmly connected, and the impact resistance and the durability for thermal contraction difference can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an assembled camshaft for use in internal combustion engines such as automobiles.

2. Description of the Related Art An assembled camshaft in which the hollow camshaft is made of reinforced plastic, the cam piece is made of metal, and the two are bonded together with adhesive is disclosed in Japanese Patent Application Laid-open No. 58-75903.

Problems to be Solved by the Invention Although gluing is used to connect the hollow reinforced glass camshaft and cam piece for economical reasons, the camshaft tends to loosen due to impact and thermal shrinkage during use. There's a problem.

A further means for solving the problem is to provide a recessed notch on the inner periphery of the cam piece, and to form a protrusion that engages with the recess on a hollow reinforced plastic camshaft that passes through the inner periphery of the cam piece.

For production The cam piece and the hollow reinforced plastic camshaft engage with each other.

Embodiments Hereinafter, the configuration of embodiments of the present invention will be explained with reference to the drawings.

In FIG. 1 and M2 diagram showing its ll-1t cross section,
1 is the assembled camshaft. 2 is a so-called filament winding (Filament winding) method, in which long synthetic fibers are wound around a mold using the camshaft, impregnated with an appropriate resin, and molded.
(Lament Winding, ) hollow reinforced plastic camshaft.

This camshaft 2 is made of long fibers selected from glass fibers, carbon fibers, etc., and plastics selected from thermosetting resins and thermoplastic resins. , and if necessary, short synthetic fibers may be mixed into the plastic.

The cam shaft 2 has no protrusion 5 when it is in a single unit state before being combined with the cam piece 3, and has a truly cylindrical shape.

The cam piece 3 is formed by selecting an appropriate material from among metal forging, sintering, ceramic, fiber-reinforced plastic, and the like.

This cam piece 3 is shaped like a square and has an inner periphery sized to allow insertion of the camshaft 2. A recessed notch 4 is formed in the inner cup of the cam piece 3 at a central portion in the axial direction of the cam piece and is recessed toward the cam top portion.

In order to connect such a camshaft 2 and a cam piece, the camshaft 2
After attaching the cam piece 3 to the mold, the cam shaft 2 is fixed to a mold (not shown), and the cam shaft 2 is heated, and internal pressure such as air pressure or hydraulic pressure is applied to the inner circumference of the cam shaft. A protrusion 5 that engages with the cutout 4 is formed protruding from a part of the camshaft 2.

At this time, if the long fibers of the camshaft 2 do not communicate with the protruding part 5 and the surrounding non-protruding parts, or if the protruding part 5 does not protrude into the desired shape, the camshaft 2
When heating and applying internal pressure, a load is further applied to shorten the camshaft 2 in the axial direction.

In the assembled camshaft thus assembled, the long fibers also pass through the protrusion 5, the camshaft 2 and the cam piece 3 are firmly connected, and the assembly can withstand impact and thermal shrinkage difference during use.

Note that the present invention is not limited to the above-mentioned embodiments. For example, as shown in FIG. 3 and the IV-IV cross section in FIG. The position of is not limited to the center of the cam piece, but may be biased to one side.

Effects As described above, according to the present invention, since the long fibers also communicate with the protrusion, the cam piece and the filament-riding hollow reinforced plastic camshaft can be firmly connected.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a partially sectional projection view of the main parts of an assembled camshaft. FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG. FIG. 2 shows another embodiment, and is a partially sectional view of a main part of an assembled camshaft. FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3. (Explanation of symbols) 2...Cam shaft 0 3""" cam piece. 4...Concave notch. 5...Protrusion.

Claims (1)

[Claims] A filament winding hollow reinforced plastic camshaft 2 in which a ring-shaped cam piece 3 is provided with a recessed part 4 on its inner periphery, and a protruding part 5 that engages with the recessed part 4 passes through the cam piece's inner periphery.
An assembled camshaft characterized by a protrusion formed by applying heat and internal pressure to the camshaft.