JPH0332294B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a small motor, and more particularly to a bottomed cylindrical bracket constituting the small motor and a method for manufacturing the same.

The external shape of a small motor is generally a cylindrical shape as shown in Fig. 1, and such a small motor can be assembled by assembling two bottomed pipe-shaped brackets 1, 1 as shown in Fig. 2. It is composed of. When assembling these two brackets 1 and 1 automatically, the outer peripheral surface of bracket 1 can be used to center both brackets for radial positioning, but in order to position bracket 1 in the rotational direction, requires some kind of improvement. Therefore, conventionally, as shown in FIGS. 3 and 4, protrusions 2 and holes 3 are provided on the plane part 1a of a bottomed cylindrical bracket 1, and these protrusions 2 and holes 3 are used for positioning in the rotational direction. However, the protrusion 2 as shown in FIG.
This is a disadvantage in terms of thinning, which is a necessary condition for small motors, and the hole 3 shown in Figure 4 is
This has the disadvantage that not only does it have a negative effect on the rotating and sliding parts, but it also releases rotational noise and electrical noise generated from inside the motor to the outside. Furthermore, as another method for positioning in the rotational direction, a method has been proposed in which a screw hole (not shown) provided in the flat part 1a is used for mounting the motor.
There is a drawback that the tip of the screw hole may be damaged during positioning.

The object of the present invention is to eliminate the above-mentioned drawbacks, to achieve a thinner motor without adversely affecting motor performance, and to enable positioning of the bracket in the rotational direction during automatic assembly.

The above-mentioned object of the present invention is achieved by providing a concave portion on the outer surface of the bottomed cylindrical bracket, which allows the bracket to be regulated in the rotational direction.

Another object of the present invention is to provide a small-diameter through hole in the flat surface of a bottomed cylindrical bracket, and then shallowly press the through hole from the outside with a punch having a somewhat larger diameter than the through hole. However, this is achieved by forming a recessed portion with a closed bottom surface in the flat portion through this press working.

Embodiments of the present invention will be described below with reference to FIGS. 5 to 8.

FIG. 5 shows an external view of a cylindrical bracket 1 according to an embodiment of the present invention. The bracket 1, which is a case or a lid, is formed from a metal plate into a bottomed pipe shape by press working. FIG. 6 shows a cross-sectional view of a corner portion of the bracket 1 extending from the flat portion 1a to the circumferential portion 1b.A bottomed recess 4 is formed in the flat portion 1a of the bracket 1. As shown in FIG. This recess 4 is formed by punching a small through hole 5 with a diameter of d ₁ in the flat part 1a of the bracket 1 as shown in FIG. It is formed by shallow pressing with a punch 6 having a diameter d ₂ somewhat larger than d ₁ and by using the movement of the excess material at this time to fill the bottom of the previously machined through hole 5 .

Note that when pressing the through hole 5 with the punch 6, the space volume of the through hole 5 with a diameter d ₁ and the recess _{4 with a diameter d 2}
If the space volume of the bracket 1 is kept the same, most of the excess material during pressing will move evenly to the bottom of the through hole 5, and the thickness of the bracket 1 will hardly change.
The thickness can be close to the standard plate thickness. The recess 4 makes it possible to position the bracket 1 in the rotational direction during automatic assembly.

As explained above, according to the present invention, each component can be automatically assembled by using the recess provided in the outer plane part of the bottomed cylindrical bracket for positioning in the rotational direction, which is suitable for thinning. can provide a small motor with less noise. Further, since the recessed portion can be formed by simple press working, productivity can be increased.

[Brief explanation of the drawing]

Figure 1 is an external view of the small motor, Figure 2 is an external view of the cylindrical bracket that makes up the small motor,
Figures 3 and 4 are external views of a conventional cylindrical bracket, Figure 5 is an external view of a cylindrical bracket according to an embodiment of the present invention, and Figure 6 is an enlarged sectional view of the vicinity of the recess in Figure 5. , FIG. 7, and FIG. 8 are explanatory diagrams showing the processing steps when forming the recessed portion. 1... Cylindrical bracket, 1a... Plane part, 4
... recess, 5 ... through hole, 6 ... punch.

Claims (1)

[Scope of Claims] 1. A small motor, characterized in that a bottomed cylindrical bracket is provided with a recessed portion on the outer surface of the bracket that can regulate the rotational direction of the bracket. 2. After forming a small diameter through hole in the flat surface of the bottomed cylindrical bracket, the through hole is shallowly pressed from the outside with a punch having a diameter slightly larger than that of the through hole, and by this pressing, the A method for manufacturing a small motor, characterized in that a recess with a closed bottom is formed in a flat part.