JPH0538527A - Assembled cam shaft and manufacture of the same - Google Patents

Abstract

(57) [Summary] [Object] To provide an assembled camshaft capable of obtaining a stable coupling force between a cam piece and a material pipe, and a manufacturing method thereof. [Configuration] A cam piece having a top portion and an inner peripheral surface of a shaft hole,
A plate member that is joined to the inner peripheral surface of the cam piece and forms a predetermined gap with the inner peripheral surface of the cam piece; and a material pipe inserted into the shaft hole of the cam piece. The material pipe is bulged and deformed by introducing a pressure fluid having a predetermined pressure to the bulge, and the plate member is bulged and deformed by the bulge deformation of the material pipe, whereby the cam piece and the material pipe are integrated. Disclosed is an assembled camshaft, which is characterized in that the camshaft is coupled with each other. Further disclosed is a method of manufacturing the assembled camshaft.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an assembled camshaft and a method of manufacturing the same, and more particularly to an assembled camshaft in which a cam piece and a material pipe are joined by bulging or the like and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, when a cam piece and a material pipe are joined together to manufacture an assembled camshaft, a pressure fluid is introduced into the material pipe while the cam piece is externally inserted into the material pipe by bulging. It is known that the cam piece and the raw material tube are connected to each other by swelling (see Japanese Patent Publication No. 2-62333).

According to the method for manufacturing an assembled camshaft described in this publication, a receiving projection is formed on the inner peripheral surface of the shaft hole corresponding to the high portion (top portion) of the cam piece and extends in the axial direction. With the material pipe inserted into the piece, a pressure fluid is introduced into the material pipe, whereby the receiving ridge of the cam piece and the part of the material tube facing it are swollen and deformed to bite the cam piece. The pressurization is stopped by the pressure fluid while a slight gap remains between the material pipe and the material pipe.

In this manufacturing method, the cam piece easily moves in the circumferential direction and the radial direction with respect to the material pipe, although the bulging is performed at a significantly lower pressure than the conventional method. Moreover, the cam piece is prevented from being damaged from the biting part with the material pipe.

[0005]

However, in the above-mentioned conventional manufacturing method of the assembled camshaft, since the bulging process is performed with a relatively low pressure, the material pipe is not limited to the cam piece, the journal piece or the like. When the above members are joined together, the pressure of the bulging process is low, and there arises a problem that a sufficient joining force between the material pipe and the other members such as the journal piece cannot be obtained.

Further, since the receiving projection of the cam piece is in a state of being bite into the material tube, the material tube may be deformed by an external force acting in the axial direction from the top portion of the cam piece. Therefore, the present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide an assembled camshaft and a manufacturing method thereof that can obtain a stable coupling force between the cam piece and the material pipe. ..

[0007]

In order to achieve the above object, an assembled camshaft according to the present invention comprises a cam piece having a top portion and an inner circumferential surface of a shaft hole, and a cam piece joined to the inner circumferential surface of the cam piece. A pressure fluid having a plate material that forms a predetermined space between the cam piece and the inner peripheral surface of the cam piece, and a material tube inserted into the shaft hole of the cam piece, and having a predetermined amount of pressure in the material tube. By introducing the, the material pipe is bulged and deformed, and the plate material is bulged and deformed by the bulging deformation of the material pipe, whereby the cam piece and the material pipe are integrally connected. There is.

According to the method of manufacturing the assembled camshaft of the present invention, a plate member is joined to the inner peripheral surface of the cam piece having the top portion and the inner peripheral surface of the shaft hole, and the plate member is provided between the inner peripheral surface of the cam piece and the inner peripheral surface. By forming a predetermined gap, inserting the material tube into the shaft hole of the cam piece, and introducing a pressure fluid having a predetermined pressure into the material tube, the material tube is bulged and deformed, and this material tube The plate member is bulged and deformed by the bulging deformation, and thereby the cam piece and the material pipe are integrally connected.

In the present invention thus constructed,
By providing a plate member and changing the characteristics of the plate member, pressure control can be easily performed during bulging, and thus a stable coupling force can be obtained between the cam piece and the material pipe.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of an assembled camshaft and a method of manufacturing the same according to the present invention will be described below with reference to FIGS. FIG. 1 is a cross-sectional view showing a cam piece and a plate material before bulging, and FIG. 2 is a cross-sectional view showing an assembled camshaft showing a state in which the cam piece and the material pipe are joined after bulging.
FIG. 3 is a diagram showing the relationship between the pressure of the introduced fluid and the porosity between the cam piece and the plate material when performing bulging.

As shown in FIG. 1, reference numeral 1 denotes a cam piece, and one side of the cam piece 1 projects in the radial direction to form a top portion 2. Further, the cam piece 1 has a shaft hole 3,
The shaft hole 3 forms an inner peripheral surface 4. The end portion 6 of the corrugated plate member 5 is joined to the portion of the inner peripheral surface 4 of the cam piece 1 where the top portion 2 is located by resistance welding or the like.
A predetermined gap 7 is formed between the inner peripheral surface 4 and the plate member 5.

The material pipe 10 is inserted into the inner peripheral surface 4 of the shaft hole 3 of the cam piece 1 thus formed.
A pressure fluid is introduced therein as described later. At this time,
The material pipe 10 is bulged and deformed, and the plate material 5 is further bulged and deformed by the bulged deformation of the material pipe 10. Here, material tube 10
A recessed portion 11 is formed at a portion where the edge portion 6 of the plate member 5 contacts.

In FIG. 3, the vertical axis represents the pressure of the fluid introduced into the material pipe 10 when bulging is performed, and the horizontal axis represents the porosity, which is the rate of change in the void 7. The porosity of 100% indicates a state before the pressure fluid is introduced into the material pipe 10, and the change rate of 0% indicates a state in which the plate material 5 is bulged and deformed and the voids 7 are eliminated. In FIG. 3, a curve A shows the case according to the embodiment of the present invention, and a curve B shows the case of the above-mentioned conventional example. In this case, the gap is formed by the cam piece and the material tube.

In the embodiment of the present invention, the pressure of the introduced fluid is set so that the desired pressure at the point a, for example, is set, and a gap is left. The characteristics of the curve A can be arbitrarily changed by changing the plate thickness, shape, material, etc. of the plate member 5. Therefore, as is clear from FIG.
In the present invention, the pressure of the introduced fluid can be adjusted on the high pressure side as a whole as compared with the prior art, and therefore stable pressure management and pressure control on the high pressure side are possible.

Next, a method of manufacturing the assembled camshaft of the present invention will be described with reference to FIGS. FIG. 4 is a sectional view showing an outline of bulge forming, FIG. 5 is an enlarged sectional view showing a state before bulge forming, and FIG. 6 is an enlarged sectional view showing a state after bulge forming. In FIG. 4, reference numeral 20 denotes a main body of the bulge processing apparatus, and an upper die 21 and a lower die 22 which are molding dies are attached to the main body 20. Between the upper die 21 and the lower die 22, the cam piece 1 and the journal piece 23, in which the plate material 5 is joined to the outer peripheral surface of the material pipe 10, are provided.
The assembled camshaft with the parts etc. externally inserted is arranged. Punches 24 are inserted into both ends of the material tube 10 to keep the inside of the material tube 10 in a sealed state. A pressure fluid is introduced into the material tube 10 from one side of the punch 24.

The upper half of the blank tube 10 in FIG. 4 and FIG.
Shows the state before bulge forming, and is the material pipe 1 in FIG.
The lower half of 0 and FIG. 6 show the state after bulging. As shown in FIGS. 4 to 6, when a pressure fluid is introduced into the material tube 10, the material tube 10 itself bulges and deforms, and then the plate material 5 bulges due to the bulging deformation of the material tube 10. It deforms to the outside, and a gap 7 is formed between the inner peripheral surface 4 of the cam piece 1 and the plate member 5.
The cam piece 1 and the material pipe 10 are joined by a predetermined joining force in a state in which the remains. At this time, the journal piece 23 and the like are also joined to the material tube 10 by a predetermined joining force.

In the embodiment of the present invention configured as described above, the plate member 5 is provided and the plate thickness, shape, material, etc. of the plate member 5 are changed, so that pressure control can be easily performed during bulging. As a result, the cam piece 1 and the material pipe 10 can obtain a stable coupling force. Also, the cam piece 1
Even with respect to the external force acting from the top part 2 of the
The recessed portion 1 is formed in the portion where the material pipe 10 comes into contact with the end portion 6 of the plate material 5.
Since 1 is formed, the material pipe 10 can be prevented by receiving an external force at the recess 11.

[0018]

As described above, according to the present invention, by providing a plate member and changing the characteristics of the plate member, pressure control can be easily performed during bulge forming, whereby the cam piece and the material can be controlled. A stable binding force can be obtained in the tube.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a cam piece and a plate material before performing bulge processing.

FIG. 2 is a cross-sectional view showing an assembled camshaft showing a state in which a cam piece and a material pipe are joined after bulging.

FIG. 3 is a diagram showing a relationship between a pressure of an introduced fluid and a porosity between a cam piece and a plate material when performing bulging.

FIG. 4 is a cross-sectional view showing an outline of bulge processing.

FIG. 5 is an enlarged cross-sectional view showing a state before bulging and forming.

FIG. 6 is an enlarged cross-sectional view showing a state after bulge forming.

[Explanation of symbols]

 1 cam piece 2 top part 3 shaft hole 4 inner peripheral surface 5 plate material 7 void 10 material pipe

Claims (2)

[Claims] 1. A cam piece having a top portion and an inner peripheral surface of a shaft hole, and a plate member joined to the inner peripheral surface of the cam piece to form a predetermined gap between the inner peripheral surface of the cam piece and A material pipe inserted into the shaft hole of the cam piece, and by introducing a pressure fluid having a predetermined pressure into the material pipe, the material pipe is bulged and deformed to expand the material pipe. An assembled camshaft, characterized in that the plate member is bulged and deformed by the protruding deformation so that the cam piece and the material pipe are integrally connected. 2. A plate member is joined to an inner peripheral surface of a cam piece having a top portion and an inner peripheral surface of a shaft hole, and a predetermined gap is formed between the plate member and the inner peripheral surface of the cam piece. The material pipe is inserted into the shaft hole, and a pressure fluid having a predetermined pressure is introduced into the material pipe to bulge and deform the material pipe, and the bulging deformation of the material pipe bulges the plate material. A manufacturing method of an assembled camshaft, characterized in that the cam piece and the material pipe are integrally connected by the deformation.