JPH0874870A - Mechanical element having shaft pressed into fitting member - Google Patents

Abstract

PURPOSE: To provide a mechanical element having no possibility of a fitting part being broken by a high load under use. CONSTITUTION: A mechanical element is formed by forming a swollen part 2 by rolling the fitting area outer circumferential surface of a shaft 1, forming an inner circumferential surface having a bore diameter smaller than the outer diameter of the swollen part 2 on at least a part of the shaft hole 11 of a fitting member 10, and pressing the swollen art 2 into the shaft hole 11 to integrally assemble the fitting member 10 and the shaft 1. A synthetic resin 5 or metal is filled in a void generated between the swollen part 2 formed in the fitting area of the shaft 1 and the shaft hole 11 of the fitting member 10 fitted to the swollen part 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a mechanical element in which a shaft as a separate member is press-fitted into a fitting member such as a cam manufactured by sintering, forging, casting or the like.

[0002]

2. Description of the Related Art A camshaft assembled by press-fitting a cam piece onto a shaft is known from Japanese Patent Laid-Open No. 63-297707. This camshaft has a threaded ridge formed on the outer peripheral surface of the fitting area of the shaft by processing such as rolling, and the shaft ridge is cut by a protrusion provided on the inner peripheral surface of the cam piece to form a groove there. Is formed by press-fitting and fitting the cam and the shaft. However, this known camshaft has the following problems. 1. In order to cut the shaft ridge by the cam piece shaft projecting part, the cam piece must be made hard and the shaft soft, but the soft hollow shaft reduces the strength by cutting, so the hollow shaft becomes thick and the shaft is lightweight. Limited 2. It takes time and effort to process the chips generated when the shaft ridge is cut by the cam piece shaft hole protrusion. 3. When the cam piece is made of only a sintered alloy material, the cam piece shaft hole protruding portion is often cracked during cutting and fitting, and even if it is not cracked during cutting and fitting, it may be cracked if a high load is applied during use.

These problems result from the fact that the shaft ridge portion is cut by the cam piece shaft hole protrusion during press-fitting and the cam and shaft are fitted together. Therefore, the problem can be solved if the cam piece shaft hole and the shaft raised portion are fitted not by cutting but by plastic deformation. To this end, the shape of the cam piece shaft hole must be suitable for plastically deforming the shaft ridge without cutting.

[0004]

The inner diameter of the cam piece axial hole is always larger than the outer diameter of the shaft (excluding the fitting portion), and the root diameter of the ridge of the shaft is always smaller than the outer diameter of the shaft. There is always a gap between the inner peripheral surface of the cam piece shaft hole and the outer peripheral surface of the shaft fitting region. When pressing the shaft into the cam piece, do not cut the shaft ridge,
A camshaft in which the campiece and shaft are integrally assembled by plastic deformation and / or elastic deformation of the campiece shaft hole and shaft ridge does not cause the campiece to crack at the time of fitting, but the campiece may crack due to high load during use. It was Since this crack occurs in the gap portion where the cam piece is not fitted to the shaft, it is caused by the deformation due to the repeated load that the gap portion of the cam piece receives.

The present invention has been made to solve the above problems, and an object of the present invention is to form a ridge by rolling the outer peripheral surface of a fitting region of a shaft and to fit the ridge. (EN) Provided is a mechanical element assembled by press-fitting and fitting a shaft hole of a coupling member, in which the coupling member is not likely to be damaged by a high load during use.

[0006]

In order to achieve the above object, the means adopted by the present invention is to form a raised portion by rolling the outer peripheral surface of the fitting region of the shaft, and to fit a cam piece or the like. The inner diameter of at least a part of the inner peripheral surface of the shaft hole of the coupling member is formed smaller than the outer diameter of the raised portion, and the raised portion is press-fitted into the shaft hole to plastically and / or elastically deform the fitting member to the shaft. This is because the gap is formed between the outer peripheral surface of the shaft fitting region and the inner peripheral surface of the fitting member shaft hole by fitting and filling with synthetic resin or metal braze.

[0007]

As described above, although there is always a gap between the fitting region of the shaft and the axial hole of the fitting member, the gap is filled with the synthetic resin or the metal brazing material filled therein. Therefore, even if the portion of the fitting member in which the void is present is subjected to repeated load in the radial direction, the deformation is very small, and therefore there is no risk of damage.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A mechanical element of the present invention will be described based on an embodiment shown in the drawings. As shown in FIG. 1, the outer peripheral surface of the fitting area of the shaft is knurled to form a flat knurl in which the raised portion 2 extends in the axial direction. The outer diameter of the portion of the shaft 1 excluding the fitting region is D0, and the raised portion 2 of the fitting region is
The outer diameter D1 of the crest 3 is larger than the shaft outer diameter D0.

The cam piece 10 shown in FIG. 2 comprises an outer piece 13 made of a sintered alloy which defines a cam profile, and an inner piece 12 made of a low carbon steel non-sintered material. The inner peripheral surface of the outer piece 13 and the outer peripheral surface of the inner piece 12 are diffusion-bonded by liquid phase sintering. Inner piece 12
The axial hole 11 is a decagon, and the minimum inner diameter D3 which is the opposite side distance thereof is smaller than the outer diameter D1 of the crest of the shaft ridge, but the maximum inner diameter D2 which is the diagonal distance is the outer diameter of the crest of the shaft ridge. Greater than D1.

As shown in FIG. 3, the raised portion 2 of the shaft 1
The anaerobic synthetic resin 5 is coated on the valley 4 of the ridge 2.
Fill in. The outer diameter of the shaft protrusion after coating is set to be approximately the same as the maximum inner diameter D3 of the cam piece 10 in FIG. While the coated synthetic resin is soft, when the cam piece 10 of FIG. 2 is press-fitted into the fitting area of the cam shaft 1 of FIG. 1 as indicated by the arrow in FIG. The small-diameter portion is plastically and / or elastically deformed to be fitted and joined to the raised portion of the shaft. At the corner portion close to the maximum inner diameter of the decagonal shaft hole 11, a gap is created because the inner piece 12 and the shaft are not directly joined, but the gap is filled with the anaerobic synthetic resin 5, and the corner of the shaft hole 11 of the inner piece 12 is filled. Even if a load is repeatedly applied to the portion, the corner portion is extremely deformed because it is filled with the synthetic resin 5. Therefore, since the strength of the cam piece against repeated load is improved, the load torque can be increased.

As shown in FIG. 5, it is also possible to use a cam piece 10 having a single-layer structure provided with a shaft hole 11 without an inner piece. Further, the cam piece need not be made of a sintered alloy, and may be a forged one or a cast one. Also, the shape of the shaft hole does not have to be polygonal, but circular,
Alternatively, the shape may be elliptical. In the examples, the flat knurls are shown as the ridges formed in the fitting region of the shaft, but the knurls are not limited to the flat knurls, and may be threaded oblique knurls or crossed knurls.
As the synthetic resin for coating the raised portion of the shaft as the filling material, a thermosetting resin can be used in addition to the anaerobic resin, and an adhesive material can be coated. When filling the gap between the shaft ridge and the cam piece shaft hole with metal, brazing metal, for example, copper braze is used. The mechanical element of the embodiment is a camshaft, but a gear,
It is also possible to press fit the shaft into the rotor to assemble the gear shaft and the rotor shaft.

[0012]

As described above, according to the mechanical element of the present invention, the outer peripheral surface of the fitting region of the shaft is subjected to the rolling process to form a ridge, and the ridge has an inner diameter smaller than that of the shaft at least partially. It is assembled by press-fitting a fitting member with a hole, but unlike the conventional one in which the gap that always occurs between the fitting area of the shaft and the shaft hole of the fitting member is left unchanged, Since the gap between the fitting region and the shaft hole of the fitting member is filled with synthetic resin or metal, the strength of the fitting member in the part where the gap is present against repeated load is improved, thereby increasing safety, It has an excellent effect that the load torque is also increased.

[Brief description of drawings]

FIG. 1 is a front view showing a main part of a shaft that constitutes a camshaft according to an embodiment of the present invention,

FIG. 2 is a plan view of a cam piece constituting a cam shaft according to an embodiment of the present invention,

3 is an enlarged cross-sectional view showing a state in which the shaft of FIG. 1 is coated with a synthetic resin,

4 is a longitudinal sectional view showing a state where the cam piece of FIG. 2 is press-fitted onto the shaft of FIG.

FIG. 5 is a view corresponding to FIG. 2 of another embodiment,

[Explanation of symbols]

1: Shaft, 2: Raised part, 3: Peak, 4: Valley, 5: Synthetic resin, 10: Cam piece, 11: Shaft hole, 12: Inner piece, 13: Outer piece

[Procedure amendment]

[Submission date] September 21, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[0002]

2. Description of the Related Art A camshaft assembled by press-fitting a cam piece onto a shaft is known from Japanese Patent Laid-Open No. 63-297707. This camshaft has a threaded ridge formed on the outer peripheral surface of the fitting area of the shaft by processing such as rolling, and the shaft ridge is cut by a protrusion provided on the inner peripheral surface of the cam piece to form a groove there. Is formed by press-fitting and fitting the cam and the shaft. However, this known camshaft has the following problems. 1. The cam piece must be hard and the shaft must be soft to cut the shaft protrusion by the cam piece axial hole protrusion, but the soft hollow shaft reduces the strength by cutting, so the hollow shaft becomes thick and the shaft is lightweight. Limited 2. It takes time and effort to process the chips generated when the shaft ridge is cut by the cam piece shaft hole protrusion. 3. When the cam piece is made of only a sintered alloy material, the cam piece shaft hole protruding portion is often cracked during cutting and fitting, and even if it is not cracked during cutting and fitting, it may be cracked if a high load is applied during use.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0005

[Correction method] Change

[Correction content]

The present invention has been made to solve the above problems, and an object of the present invention is to form a ridge by rolling the outer peripheral surface of a fitting region of a shaft and to form the ridge on the ridge. (EN) Provided is a mechanical element assembled by press-fitting and fitting a shaft hole of a fitting member, in which the fitting member is not likely to be damaged by a high load during use.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

As shown in FIG. 3, the raised portion 2 of the shaft 1
The anaerobic synthetic resin 5 is coated on the valley 4 of the ridge 2.
Fill in. The outer diameter of the shaft protrusion after coating is set to be approximately the same as the maximum inner diameter D 2 of the cam piece 10 in FIG. While the coated synthetic resin is soft, when the cam piece 10 of FIG. 2 is press-fitted into the fitting area of the cam shaft 1 of FIG. 1 as indicated by the arrow in FIG. The small-diameter portion is plastically and / or elastically deformed to be fitted and joined to the raised portion of the shaft. At the corner portion close to the maximum inner diameter of the decagonal shaft hole 11, a gap is created because the inner piece 12 and the shaft are not directly joined, but the gap is filled with the anaerobic synthetic resin 5, and the corner of the shaft hole 11 of the inner piece 12 is filled. Even if a load is repeatedly applied to the portion, the corner portion is extremely deformed because it is filled with the synthetic resin 5. Therefore, since the strength of the cam piece against repeated load is improved, the load torque can be increased.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction content]

As shown in FIG. 5, it is also possible to use a cam piece 10 having a single-layer structure provided with a shaft hole 11 without an inner piece. Further, the cam piece need not be made of a sintered alloy, and may be a forged one or a cast one. Also, the shape of the shaft hole does not have to be polygonal, but circular,
Alternatively, the shape may be elliptical. In the examples, the flat knurls are shown as the ridges formed in the fitting region of the shaft, but the knurls are not limited to the flat knurls, and may be threaded oblique knurls or crossed knurls.
Synthetic resin for Coated ring on the raised portion of the shaft as filler it is also possible to use a thermosetting resin in addition to the anaerobic resin, It is also possible to Coated packaging an adhesive. When filling the gap between the shaft ridge and the cam piece shaft hole with metal, brazing metal, for example, copper braze is used. The mechanical element of the embodiment is a camshaft, but a gear,
It is also possible to press fit the shaft into the rotor to assemble the gear shaft and the rotor shaft.

[Procedure Amendment 5]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 2

[Correction method] Change

[Correction content]

[Fig. 2]

Claims (1)

[Claims] Claim: What is claimed is: 1. A fitting member (10) comprising a raised portion (2) formed by rolling the outer peripheral surface of a fitting region of a shaft (1).
At least a part of the shaft hole (11) has an inner diameter smaller than the outer diameter of the raised portion (2), and the raised portion is press-fitted into the shaft hole to plastically and / or elastically deform the fitting member. A mechanical element in which the shaft and the shaft are integrally assembled, wherein a gap generated between the shaft fitting region and the shaft hole is filled with a synthetic resin or a metal brazing material, and the shaft is press-fitted into the fitting member. Machine element consisting of.