JPH0318256A - Manufacture of hollow core shaft member - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method of manufacturing a hollow core shaft member in which a groove portion such as a pulley attachment portion or a gear portion is formed.

[In general, the problems to be solved by the prior art and the invention,
Some core shafts of motors and the like are formed with grooves such as pulley attachment portions and gear portions, but this core shaft may be made hollow to reduce weight, for example. However, conventionally, in order to manufacture a hollow core shaft with a groove formed in this way, as shown in FIG. It was heat treated to improve hardness. However, in this case, the thin part of the formed groove may be deformed or damaged by heating, making it difficult to provide reliable, high-quality products in large quantities at low cost. .

[Means for Solving the Problems] In view of the above-mentioned circumstances, the present invention was devised for the purpose of providing a method for manufacturing a hollow core shaft material that can eliminate these drawbacks. To manufacture a hollow core shaft material with a groove formed on the outer periphery, the groove is formed in a shaft member that is not hollow at least in a groove shape, and after heat treatment, the shaft member is made into a hollow shape. It is characterized by being processed.

According to the present invention, a highly accurate hollow core shaft material can be easily and reliably manufactured using this method.

[Example] Next, an example of the present invention will be described based on the drawings. In the drawing, 1 is a motor, and the motor 1 is in sliding contact with a motor yoke 2, a core shaft member 3 that is rotatably supported on the motor yoke 2, an armature core 5 around which a coil is wound, and a brush 6. The components such as the commutator 7 and the permanent magnet 8 are all the same as before.

The core shaft material 3 has a hollow cylindrical shape, and a groove portion 4 for attaching a pulley is formed at the tip of the core shaft material 3 protruding from the motor yoke 2. Shaft material 3
is manufactured as follows.

That is, 9 is a solid shaft blank (corresponding to the shaft member of the present invention) which is the material of the core shaft material 3, and one end of the blank shaft 9 has a temporary boss portion 9a for a jig. It is provided. First, knurling is performed on the outer circumferential portion of the shaft blank 9 at a portion where the armature core is fixed. Next, the groove 4 is formed at a predetermined position on the outer periphery of the shaft blank 9. Thereafter, a heat treatment inhibitor is applied to the temporary boss portion 9a, and then the shaft 1 and the blank 9 are heat treated, and then the armature core 5 is press-fitted into the knurl 1 and the processed portion l○ of the shaft blank 9. After that,
The shaft blank 9 is processed into a hollow shape, whereby the boss portion 9a is also removed, and a hollow core shaft member 3 in which the groove portion 4 is formed is manufactured.

In the embodiment of the present invention constructed as described above, the solid shaft 1/blank 9, which is the material of the core shaft material 3, is first subjected to knurling, groove 4 formation, heat treatment, and armature core 5 press-fitting. After that, a hollow core shaft material 3 with grooves 4 formed therein is manufactured.

As described above, in the present invention, the core shaft 3 is manufactured by hollowing the solid shaft blank 9 after subjecting it to drilling into the groove 4, heat treatment, press-fitting the armature core 5, etc. Therefore, it is possible to effectively avoid deformation or damage of the thin wall portion of the groove portion 4 due to heat treatment or press-fitting of the armature core, and to reliably manufacture a highly reliable hollow core shaft 3. can do.

[Operations and Effects] In summary, the present invention is constructed as described above, and the core shaft material is manufactured by forming grooves in the shaft member, heat-treating it, and then processing it into a hollow shape. Therefore, it is possible to effectively avoid deformation or damage of the thin wall portion of the groove due to heat treatment, which is the case when a groove is formed in a hollow shaft member and heat treated as in the conventional method. Even if the core shaft material has a shape, it is possible to easily and reliably provide high-quality, highly accurate core shaft materials.

[Brief explanation of drawings]

The drawings show an embodiment of the method for manufacturing a hollow core shaft material according to the present invention, and FIG. 1 is a schematic sectional view of a motor, and FIG. 2 is a schematic sectional view of a motor. B. C is an explanatory diagram showing the manufacturing process of the core shaft material, and FIG. 3A. B. FIG. 4A is a schematic cross-sectional view of a motor with various grooves formed therein. B. C. D is an explanatory diagram showing a manufacturing process in a conventional example. In the figure, 3 is a core shaft material, 4 is a groove, and 9 is a shaft 4-blank.

Claims (1)

[Claims] In order to manufacture a hollow core shaft material having a groove formed on the outer periphery, at least the groove forming portion is formed in a shaft member that is not hollow, and after heat treatment is performed, the shaft member is processed into a hollow shape. A method for manufacturing a hollow core shaft material, characterized by: