JPH0275424A - Method for caulking sintered parts - Google Patents

Abstract

PURPOSE:To improve the torque after caulking a pin, etc., and the sintered parts at low cost by providing a recess in the peripheral direction nearly on the end face of the sintered parts then fixing the side provided with the hollow to caulk. CONSTITUTION:On at least one of the sintered parts 1 near a hole 7 disposed on its end face of the side to be caulked, one or more recesses 2 are formed in the peripheral direction. These recesses 2 are provided properly chamfering the inlet part of the said hole 7 in the peripheral direction, to form alternately with projected parts 1 without chamfering. Then, the members 5 of the pin and shaft, etc., are inserted into said hole 7 to fix on the sintered parts 4 by caulking. By this caulking, the material of said member 5 flows plastically into said recess 2. By this method, the effect of a detent is exhibited to obtain the high torque strength.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a method for caulking members such as pins and shafts of sintered parts that can obtain high rotational torque strength.

"Prior art" Sintered parts that have shape or material restrictions are often combined with other parts to form a single part, and it is cheaper to caulk one of them together. This is done as an easy method.

However, when caulking members such as pins and shafts to sintered parts, rotational torque is obtained only from the frictional force caused by caulking K, so it cannot be applied to parts that require high rotational torque strength, and there are only a few fields where it can be applied. It was limited.

``Problems to be Solved by the Invention'' Conventionally, when caulking members such as pins and shafts to sintered parts, if high rotational torque strength is required, the amount of caulking is increased; High turning torque was obtained due to the frictional force of the surfaces.

However, according to that method, a large force was applied to the sintered parts and the caulked parts, resulting in deformation. However, in severe cases, there was a problem that it could lead to the destruction of parts.

There is also a method of making the hole shape itself irregular, but there is a problem in that members such as caulking pins and shafts become relatively expensive, leading to an increase in cost.

"Means for Solving the Problems" In view of the above, the present invention was developed to solve these problems.

That is, the method for caulking a sintered component of the present invention is a method of inserting a member such as a pin or a shaft into a hole of a sintered component and fixing the member such as a pin or shaft by caulking. By providing one or more recesses in the circumferential direction near the hole, the torque after caulking the sintered parts with members such as pins and shafts is improved.

The present invention will now be described in detail with reference to the illustrative drawings.

As illustrated in Fig. 1.2, (4) is a sintered part, for example, an iron-based sintered machine part, and a recess is provided in the circumferential direction at the entrance part of the hole (7). When the pin (or shaft) (5) is caulked, the material of the pin flows plastically and enters the recess (see Figure 1).
(see figure), it has a rotation prevention effect and can generate high rotational torque.

In Figure 1.2, (1) shows the convex part where the chamfer is omitted, (2) shows the concave part where the chamfer is omitted, and (3) C shows the step caused by (1) and (2). There is.

Also, Figure 1 (b), Figure 2 (a), and (b) are Figure 1:a)
This is an A-0-A cross section.

"Operation" By caulking in the manner described above, the portion that bites into the uneven portion acts as a stopper in the rotational direction, significantly improving torque strength.

Furthermore, since the sintered parts are molded using a metal mold, this can be achieved by providing the mold with a convexity corresponding to the concavity of the product, and since the shape of the concavity can be made arbitrarily, the increase in cost is negligible.

"Example" Examples of the present invention will be described below.

A comparison with a conventional method will be shown for an example in which a pin is caulked into a hole in a sintered part.

In the case of the conventional sintered part shown in Fig. 3, where the hole entrance is chamfered, the torque around the pin is maintained only by the frictional force of the end face (6) as shown in Fig. 4. The step (3) between the omitted part (1) and the chamfered part (2) acts as a stopper, and as shown in Figure 5, which shows the results of measuring the rotational torque, approximately 5 times the rotational torque can be achieved under the same caulking conditions. was completed. In Fig. 3.4, the same reference numerals as in Fig. 1.2 represent the same parts.

"Effects of the Invention" As explained above, according to the present invention, high torque strength can be obtained with almost no increase in cost when caulking members such as pins and shafts of sintered parts.

Therefore, it is very useful because it can be applied not only to parts with light specifications such as office equipment, but also to parts that require high torque strength such as automobile parts.

[Brief explanation of the drawing]

Figures 1 (a) and (b) are a partially omitted plan view (Figure (a)) of a hole entrance chamfer when applying the method of the present invention and its A-0-A sectional view (Figure (b). )), Figure 2(a), (
b) is the method of caulking the pin in the hole shown in Figure 1 (Figure (a))
and a diagram showing the caulked state (Figure (b)), Figure 3: a)
, (b) is a diagram of the usual hole entrance chamfering when applying the conventional method, and Figures 4 (a) and (b) are the method of caulking the pin in the hole of Figure 3 (Figure a)) and Caulked state (Fig.
b)) and FIG. 5 are diagrams illustrating the measurement results of rotational torque strength of the example product of the present invention and the conventional product, respectively. (1)...Convex part where chamfering is omitted, (2)...
...The part where the chamfer becomes a recess, (3)...(1)
and (2), (4)... Sintered parts, (5)... Members such as pins and shafts, (6)... End surfaces, (7)... Ana representative, patent attorney. Masashi Yoshitake

Claims (1)

[Claims] (1) In a method of inserting a pin, shaft, or other member into a hole in a sintered part and fixing the pin, shaft, or other member by caulking, at least one location in the circumferential direction near the hole on the end face on the side to be caulked. A method for caulking a sintered part, characterized in that by providing the above-mentioned recesses, the torque after caulking the sintered part with members such as pins and shafts is improved.