JP2002199647A - Yoke of motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a yoke capable of reducing in manufacturing cost with abolition of cutting process in chambering. SOLUTION: A plain steel lumber 3 used for a yoke is provided with stamping a material into a rectangle shape with a fixed width by pressing, and also in a state of plain board before rounding into a cylindrical shape, chamfering C, for example, C 45, are pre-provided at both end face corner parts in the width direction. This chamfering C is processed in a press processing and when the lumber 3 is rounded into the cylindrical shape, a bracket is provided at corner parts of inside diameter side of the yoke which is fitted with inlay. In other word, the steel lumber 3 is rounded in such a way that the side processed in chamfering C in the direction of board-width of the lumber 3 itself becomes to the inside diameter side of the yoke. Accordingly, there is no need of chamfering C by cutting process as usual after forming in the cylindrical shape with rounding the lumber 3, so that it is possible to abolish cutting process after forming in the cylindrical shape and possible to reduce in cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a yoke for a motor.

[0002]

2. Description of the Related Art Conventionally, a yoke used for a motor such as a starter is usually manufactured by rolling a flat steel material into a cylindrical shape, and joining the butted ends thereof (see Japanese Utility Model Application Laid-Open No. 58-158).
-97957, JP-A-64-60247). Also, since a bracket or the like fits into the open end of the yoke, a chamfer is formed on the inner diameter side corner of the yoke to avoid interference with the bracket.

[0003]

However, since the chamfering of the yoke is performed by cutting a flat steel material into a cylindrical shape after rounding it, there has been a problem that the manufacturing cost of the yoke increases. The present invention has been made based on the above circumstances, and an object of the present invention is to provide a yoke capable of reducing manufacturing costs by eliminating a cutting process when chamfering.

[0004]

(Means for Solving the Problems) A motor in which a flat steel material is rolled and formed into a cylindrical shape, and chamfered at the inner diameter side corner or the outer diameter side corner at both axial end surfaces. , Wherein a flat steel material before being rounded into a cylindrical shape is provided with a chamfer in advance. In the present invention, after the flat steel material is rounded and formed into a cylindrical shape, it is not necessary to perform chamfering by cutting, so that cutting after forming can be eliminated. When a mating member (eg, a bracket) that is combined with the yoke in the axial direction is fitted to the inner diameter side of the yoke, a chamfer is provided at the inner diameter side corner of the yoke, and the mating member is changed to the outer diameter of the yoke. When fitted to the side, a chamfer is provided at the outer diameter side corner of the yoke.

(Claim 2) In the motor yoke according to claim 1, the chamfering is performed by press working. In this case, machining is easier than conventional cutting, and chamfering can be performed at low cost.

According to a third aspect of the present invention, in the motor yoke according to the first or second aspect, the flat steel material is provided by being cut into a fixed width by a press, and a drooping side at the time of pressing generated in a cross section thereof is formed on the outside. And rounded into a cylinder.
In this case, since the fractured surface side of the flat steel material cut by the press is the inside of the cylindrical shape, when the flat steel material is rolled, the fractured surface is not expanded in the circumferential direction, and the occurrence of cracks that progress from the fractured surface can be prevented. .

According to a fourth aspect of the present invention, in the yoke of the motor according to the first or second aspect, the flat steel material is provided by being cut into a fixed width by a press, and a drooping side at the time of pressing generated in a cross section thereof is formed inside. And rounded into a cylinder.
In this case, the fractured surface side of the flat steel material cut by the press is the outer side of the cylindrical shape, but if the mating member combined with the yoke is fitted to the outer diameter side of the yoke,
Since a chamfer can be provided at the outer diameter side corner portion (fracture surface side) of the yoke, it is possible to prevent the occurrence of cracks from the fracture surface. Of course, even when the fractured surface side of the flat steel material is inside the cylindrical shape, the mating member combined with the yoke is fitted to the inner diameter side of the yoke, and the chamfer is formed on the inner diameter side corner (whore side) of the yoke. It is also possible to provide.

[0008]

Next, embodiments of the present invention will be described with reference to the drawings. (First Embodiment) FIG. 1 is a side view (a) and a plan view (b) of a flat steel material 3. The yoke 1 according to the present embodiment is used, for example, for a starter motor of an automobile starter. As shown in FIG. The yoke 1 is manufactured by rolling a flat steel material 3 shown in FIG. 1 in a longitudinal direction (a vertical direction in FIG. 1B) into a cylindrical shape.

The flat steel material 3 is a plate-like material (not shown).
1A, a plurality of protrusions 3a (tab tails) are provided at one end in the longitudinal direction, and a plurality of recesses are provided at the other end, as shown in FIG. 1B. 3b is formed. As shown in FIG. 3A, the projection 3a and the recess 3b are engaged with each other in a state where the flat steel material 3 is rolled into a cylindrical shape.

[0010] In addition, as shown in FIG.
In the state of a flat plate before being rounded into a cylindrical shape, a chamfer C (for example, C45) is formed in advance at the corners of both end surfaces in the width direction (the left-right direction in FIG. 1).
Is provided. This chamfering C is performed by press working, and is provided at a corner on the inner diameter side of the yoke 1 where the bracket 2 is spigot-fitted when the flat steel material 3 is rounded into a cylindrical shape.
In other words, the flat steel material 3 is rounded so that the side on which the chamfer C is applied in the thickness direction of the steel plate 3 is the inner diameter side of the yoke 1 (see FIG. 3).

(Effect of the present embodiment) The yoke 1 of the present embodiment
Is provided with a chamfer C in advance on the flat steel material 3 before being rounded into a cylindrical shape. In this case, after the flat steel material 3 is rounded and formed into a cylindrical shape, it is not necessary to perform the chamfering C by a cutting process as in the related art, so that the cutting process after the cylindrical forming can be eliminated,
Cost reduction is possible. In particular, if the flat steel material 3 is not rounded into a cylindrical shape, the chamfering C can be easily performed by a press. Therefore, when the flat steel material 3 is punched by a press, the chamfering process can be performed at the same time.

In the first embodiment, the bracket 2 is spigot-fitted on the inner diameter side of the yoke 1.
For example, as shown in FIG. 4, the present invention can be applied to a configuration in which a bracket 2 is spigot-fitted to the outer diameter side of a yoke 1. However, in this case, a chamfer C is provided at the outer diameter side corner of the yoke 1. In other words, the flat steel material 3 is rounded so that the side on which the chamfer C is applied in the thickness direction of the plate steel 3 is the outer diameter side of the yoke 1. Further, the flat steel material 3 may be provided by previously cutting a strip-shaped material having a certain width at a portion of the convex portion 3a and the concave portion 3b.

(Second Embodiment) FIG. 5 is a side view (a) and a front view (b) showing a cross section of a flat steel material 3 cut by a press. The present embodiment is an example in which a press droop side generated when both end faces in the width direction of the flat steel material 3 are cut by a press is set as an outer diameter side of the yoke 1. That is, when both end surfaces in the width direction of the flat steel material 3 are cut by a press, as shown in FIG.
A press droop 4 is formed on the upper side of the cut surface, and a fracture surface 5 is formed following the press droop 4.

Here, as shown in FIG. 6A, when the yoke 1 is formed with the press droop 4 side on the inner diameter side, the bracket 2 is spigot-fitted on the inner diameter side of the yoke 1 as shown in FIG. If it is a structure that matches, it is also possible for the press droop 4 to obtain the same effect as the chamfer C. However, as shown in FIG. 6B, when the flat steel material 3 is rolled so that the fracture surface 5 is on the outer diameter side of the yoke 1, the fracture surface 5 is expanded in the circumferential direction. May progress.

Therefore, in this embodiment, the fracture surface 5 is set to the inner diameter side of the yoke 1 and the chamfer C is provided on the fracture surface 5 (see FIG. 3B). Thereby, the fracture surface 5
Cracks can be prevented from progressing, and the durability can be improved. Further, since the fractured surface 5 is not exposed on the outer diameter side of the yoke 1, it is possible to prevent a situation in which an operator touches the fractured surface 5 and is injured, which is also effective in terms of safety.

When the bracket 2 is spigot-fitted to the outer diameter side of the yoke 1, a chamfer C is provided at the outer diameter side corner of the yoke 1. Also in this embodiment, it goes without saying that the chamfering is provided on the flat steel material 3 before being rounded into a cylindrical shape, as in the first embodiment.

(Modification) In the first embodiment and the second embodiment, the chamfer C is provided.
Without being limited to 5 degrees, for example, 30 degrees, 60 degrees, etc.
It can be set freely as appropriate. Further, not only the chamfer C but also a chamfer R may be used.

[Brief description of the drawings]

FIG. 1 is a side view (a) and a plan view (b) of a flat steel material (first embodiment).

FIG. 2 is a sectional view showing a fitted state of a yoke and a bracket.

FIGS. 3A and 3B are a perspective view showing the overall shape of the yoke and a cross-sectional view of the end of the yoke.

FIG. 4 is a cross-sectional view showing a fitted state of a yoke and a bracket.

FIG. 5 is a side view (a) and a front view (b) showing a cross-sectional state of a flat steel material cut by a press (second embodiment).

6A is a sectional view of the end of the yoke, and FIG. 6B is a front view of the yoke seen from the axial direction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Yoke 3 Flat steel material 4 Press droop C chamfer

Claims (4)

[Claims] 1. A motor yoke in which a flat steel material is rolled and formed into a cylindrical shape, and a chamfer is applied to an inner diameter side corner or an outer diameter side corner at both axial end surfaces thereof, before being rounded into a cylindrical shape. The yoke of the motor, wherein the chamfer is provided in advance on the flat steel material. 2. A motor yoke according to claim 1, wherein said chamfering is performed by press working. 3. The yoke for a motor according to claim 1, wherein the flat steel material is cut into a predetermined width by a press, and is provided with a cylindrical shape with a cross section of the flat steel material having a drooping side at the time of the press. A yoke for a motor, characterized in that the yoke is rounded. 4. The yoke for a motor according to claim 1, wherein the flat steel material is cut into a fixed width by a press, and is provided with a cylindrical shape with a drooping side at the time of press generated in a cross section thereof being inside. A yoke for a motor, characterized in that the yoke is rounded.