JP2003339131A - Motor case - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily enhance work precision at an alignment part for a mating case. <P>SOLUTION: A motor case 3 is a press mold of a cylindrical cup, where four tabs 10 are circumferentially protruded with a space on an open end surface. The open end surface between adjoining two tabs 10 is made to abut against an alignment wall of a mating case, for mutual alignment with the mating case. The tabs 10 are caulked over the mating case under the condition, of being coupled integrally with the mating case. Among the open end surfaces formed among the adjoining two tabs 10, a pair of open end surfaces 11 radially facing each other are worked as an alignment open end surface abutting with the alignment wall of the mating case. The other pair of open end surface 12, facing each other radially, is so formed as recessed from the alignment open end surface 11, to be a non-alignment open end surface that holds a gap before the alignment wall of the mating case. <P>COPYRIGHT: (C)2004,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor case such as a wiper motor of an automobile. 2. Description of the Related Art A wiper motor for an automobile has a structure in which a motor section and a reduction section are integrally combined, and a motor case forming an outer shell of the motor section and a gear case forming an outer shell of the reduction section. By combining with an appropriate positional relationship,
The motor section and the reduction section are integrated. In this type of wiper motor, a motor case also serving as a yoke is press-molded into a cylindrical cup shape, and four claw portions are projected from an opening end surface of the wiper motor at intervals in a circumferential direction, and each adjacent claw is provided. The gear case and the motor case are positioned relative to each other by abutting the four open end faces between the portions on the positioning wall of the gear case (the counterpart case), and in this state, the claws are swaged to the gear case case. ,
There is one in which a gear case and a motor case are integrally connected. [0004] When the above-mentioned motor case is used, after the motor case is press-formed into a cylindrical cup shape, the four opening end faces divided by the claws are formed with uniform dimensional accuracy. Although it is machined, it is difficult to uniformly control the dimensional accuracy of the four open end faces that are the mating surfaces with the gear case, and the assembly accuracy when the motor case is combined with the gear case tends to be poor, resulting in To
The noise and vibration performance of the wiper motor could be adversely affected. In view of the above circumstances, the present invention makes it possible to easily increase the processing accuracy of a portion positioned with respect to a partner case, and as a result, to improve the assembly accuracy when the motor is coupled to the partner case. The purpose is to provide a case. [0006] In order to solve the above-mentioned problems, the invention according to claim 1 is characterized in that four claw portions are press-formed into a cylindrical cup shape and are circumferentially spaced on an opening end surface. Are protruded, and are positioned relative to each other by abutting an opening end face between two adjacent claws against a positioning wall of the mating case, and in this state, the claws are positioned with respect to the mating case. By caulking, in the motor case integrally connected with the mating case, of the pair of opening end surfaces formed between the two adjacent claw portions, the pair of opening end surfaces facing each other in the radial direction is connected to the mating case. It is processed as an opening end face for positioning that abuts against the positioning wall of the case, and another pair of opening end faces facing each other in the radial direction is formed at a position retracted from the opening end face for positioning. The opening is formed as a non-positioning opening end face for maintaining a gap between the positioning wall of the counterpart case and the positioning wall. In the present invention, since only two of the four open end faces are used as reference surfaces for positioning with the counterpart case, all four open end faces are machined. Unlike the case where the accuracy is obtained uniformly, the accuracy control becomes easy by the reduced number to the minimum necessary, and the processing accuracy is easily obtained. An embodiment of the present invention will be described below with reference to the drawings. 1 is an external side view of a wiper motor using the motor case of the embodiment, FIG. 2 is a configuration diagram of the motor case, (a) is a front view seen from an opening side, (b)
Is a side sectional view. The wiper motor shown in FIG. 1 has a motor unit 1 and a reduction unit 2 integrated with each other, and a motor case 3 forming an outer shell of the motor unit 1 and a gear case 4 forming an outer shell of the reduction unit 2 are appropriately formed. The motor unit 1 and the speed reduction unit 2 are integrally combined by coupling with each other in a positional relationship. An aluminum gear case 4 is provided with a flange 5 for coupling the motor case 3, and a positioning wall 6 for positioning the motor case 3 is provided on the front surface of the flange 5. The positioning wall 6 is machined in the same plane over the entire circumference. An engagement groove 7 for engaging a claw portion 10 of the motor case 3 described later is formed on the rear side of the flange 5. On the other hand, as shown in FIG. 2, a motor case 3 made of a steel plate also serving as a motor yoke has a cylindrical wall 3a and a bottom wall 3a.
b, and is pressed into a cylindrical cup shape having a bottom wall 3b.
Is formed with a cylindrical portion 3c for assembling the bearing. Four claw portions 10 project from the opening end surface of the motor case 3 at intervals in the circumferential direction.
Of the four open end faces divided between the two claw portions 10,
A pair of radially opposed open end surfaces 11 [FIG.
The hatched portion in FIG.
Is processed as a positioning opening end surface (reference surface) that abuts against the positioning wall 6 on the side, and the other pair of opening end surfaces 12 has a smaller dimension H than the positioning opening end surface 11.
By being in the retracted position only, it is processed as an opening end surface for non-positioning which holds a gap H (see FIG. 1) between the positioning wall 6 and the gear case 4 side. In order to assemble the motor case 3 with the gear case 4, two positioning opening end faces 11 at positions facing each other in the radial direction are brought into contact with the positioning wall 6 on the motor case 4 side. And gear case 4
And position each other. Then, in this state, the claws 10 on the motor case 3 side are crimped to the engagement grooves 7 of the gear case 4, so that the motor case 3 and the gear case 4 are integrally connected. In this case, of the four open end surfaces divided by the claw portion 10, only two open end surfaces 11 are used as open end surfaces (reference surfaces) for positioning with the gear case 4, so that all four open end surfaces are used. Unlike opening the end face with uniform precision by machining, the precision control during processing becomes easier and the higher precision is easily achieved by reducing the number to the minimum necessary. Therefore, the assembling accuracy when coupled to the gear case 4 can be improved, and vibration and vibration as the wiper motor can be improved.
Noise performance can be improved. FIG. 3 shows a motor case 3 having a structure in which the motor case 3 shown in FIG.
0 is shown. To improve the performance of the yoke, it is easy to increase the thickness of the motor case.However, if a thick steel plate is press-formed from the beginning, the parts not used as the yoke, that is, the parts not used for forming the magnetic path, will also be thick. It becomes meat and the whole weight increases. Therefore,
In order to increase the substantial thickness of the portion used as the yoke, the inner yoke 23 is pressed into only that portion. The above-mentioned motor case 3 used as the outer yoke (hereinafter referred to as "outer yoke 3") is a press-processed product, so that the taper whose inner diameter gradually narrows from the open end side to the back. It has a shape. In order to press-fit the inner yoke 23 into its inner periphery, the inner yoke 23
As shown in FIG. 4, a strip 23a having a cylindrical shape is used. FIG. 4A shows a state in which the belt 23a is rolled into a cylindrical shape, and FIG. A plurality of protrusions 25 are formed on one side of the butted ends 24 that abut each other when they are rolled up to cover a crushing allowance at the time of press-fitting. When the inner yoke 23 thus constructed is inserted into the outer yoke 3, the inner diameter of the outer yoke 3 becomes narrower as the inner yoke 23 is inserted deeper. Since the projections 25 are crushed as the press-fitting is performed, the press-fitting is easily performed while absorbing the dimensional variation of the inner diameter of the outer yoke 3 and the outer diameter of the inner yoke 23. When the inner yoke 23 is press-fitted into the outer yoke 3 as described above, a magnet 50 is fitted on the inner periphery thereof as shown in FIG. As described above, the motor case 30 having a sufficient yoke plate thickness for forming the magnetic circuit while minimizing the increase in weight is completed. In the above embodiment, the case of the motor case of the wiper motor has been described as an example. However, the present invention can be applied to motor cases of other types of motors. As described above, according to the first aspect of the present invention, of the four open end surfaces divided by the claw portion, only two open end surfaces are used for positioning with the counterpart case. Since it is used as a reference surface, it is easy to manage the processing accuracy and improve the accuracy. Therefore, the assembling accuracy when combined with the mating case is enhanced, which can contribute to improvement in noise and vibration performance.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view showing the appearance of a wiper motor using a motor case according to an embodiment of the present invention. FIG. 2 is a configuration diagram of a motor case according to the embodiment of the present invention;
(A) is a front view, (b) is a side sectional view. FIG. 3 is a side sectional view showing a motor case having a structure in which an inner yoke for improving yoke performance is press-fitted into the motor case of FIG. 2; 4A and 4B are configuration diagrams of an inner yoke in FIG. 3, in which FIG. 4A is a side view before press-fitting, and FIG. 4B is a developed view before rolling. FIG. 5 is a side sectional view showing a state where a magnet is fitted to the motor case of FIG. 3; [Description of Signs] 3 Motor case 4 Gear case (mating case) 6 Positioning wall 10 Claw portion 11 Opening end face for positioning 12 Opening end face for non-positioning

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Yasushi Ohashi             1760 Higashimatano-cho, Totsuka-ku, Yokohama-shi, Kanagawa             Automotive Electric Industry Co., Ltd. F-term (reference) 3D025 AE02                 5H605 AA08 BB05 BB17 CC01 CC08                       DD05 DD09 EA06

Claims (1)

Claims: 1. A press-molded cylindrical cup shape, and four claw portions projecting from an opening end face at a circumferential interval, between two adjacent claw portions. The motor case, which is integrally connected to the mating case, is positioned relative to the mating case by abutting the opening end face of the mating case against the positioning wall of the mating case, and by crimping the claws to the mating case in that state. In the method, among a pair of open end surfaces formed between the two adjacent claw portions, a pair of open end surfaces facing each other in the radial direction are machined as a positioning open end surface which abuts against a positioning wall of the counterpart case. At the same time, another pair of opening end faces facing each other in the radial direction is formed at a position retracted from the opening end face for positioning, and a gap is held between the pair of opening end faces with the positioning wall of the counterpart case. Motor case, characterized in that processed as an opening end face for non-positioning.