JPH0318247A - Commutator and manufacture thereof - Google Patents

Abstract

PURPOSE:To facilitate a manufacture of a commutator by manufacturing it with a cylindrical ceramic supporter for commutator segments having protruding parts which are arranged extensively on the peripheral surface of the support at predetermined spaces in the axis direction of the supporter, plated layer segments which are formed on the peripheral surface of the supporter and isolated dielectrically by the protruding parts, and the commutator segments brazed on the plated layer segments. CONSTITUTION:A cylindrical ceramic supporter 12 for commutator segments having protruding parts 11 which are arranged extensively on the peripheral surface of the supporter at predetermined spaces in the axis direction of the supporter is formed (a first production process). The peripheral surface of the supporter 12 for commutator segments is plated (a second production process). A plated layer 13 is ground to a diameter at which the protruding parts 11 are exposed (a third production process). Commutator segments 14 are brazed respectively on the respective plated layer segments 13 left on the peripheral surface of the supporter 12 for the commutator segments (a fourth production process) and a commutator 10 is manufactured. Thereby, the supporter 12 for the commutator segments has a simple structure in which only the protruding parts 11 are formed, and the manufacture is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a commutator for a starter motor or the like for an internal combustion engine of a vehicle.

[Prior Art] Conventionally, resin molding has been a common method for fixing the commutator pieces to the commutator piece holder in the commutator of a starter motor, but in order to improve heat resistance, the commutator piece holder ( The use of ceramic as a molding material is being considered. As shown in FIG. 7, a fitting part 2 is formed on a commutator piece holder 1 made of ceramic, and the fitting part 2 of the commutator piece holder 1 is fitted with the commutator piece 3. By this, the commutator piece 3 is held.

[Problems to be Solved by the Invention] However, in such a commutator, the commutator piece holder 1 made of ceramic needs to be brought into close contact with the commutator piece 3, and the molding process 2 of the commutator piece holder 1 is Since the commutator piece holder 1 would shrink in the subsequent firing process, it was difficult to form the fitting portion 2 into a shape that would bite (reverse taper shape).

An object of the present invention is to provide a commutator in which a ceramic commutator piece holder can be easily manufactured.

[A first invention for solving the problem is a commutator piece holder made of a cylindrical ceramic having protrusions extending at predetermined intervals in the axial direction of the outer circumferential surface; Its gist is a commutator consisting of a plating layer formed on the outer peripheral surface of a commutator piece holder and insulated and separated by the protrusion, and a commutator piece soldered onto the plating layer. .

A second invention includes a first step of forming a commutator piece holder made of a cylindrical ceramic that shifts protrusions extending at predetermined intervals in the axial direction of the outer circumferential surface; A second step of plating the outer circumferential surface of the commutator piece holder, a third step of grinding the plating layer until the diameter of the protrusion is exposed, and each plating layer remaining on the outer circumferential surface of the commutator piece holder. The gist of the method is a method for manufacturing a commutator, which includes a fourth step of brazing commutator pieces on top of each of the commutator pieces.

[Function] In the first invention, protrusions extend at predetermined intervals in the axial direction of the outer peripheral surface of the commutator piece holder made of cylindrical ceramic, and the plating layer is insulated and separated by the protrusions. is formed on the outer peripheral surface of the commutator piece holder, and the brazed commutator pieces are arranged on this plating layer. As a result, the commutator piece holder can have a simple structure with only projections.

In the second invention, a commutator piece holder made of cylindrical ceramic having protrusions extending in the axial direction of the outer peripheral surface at a predetermined interval is formed in the first step, and the commutator piece holder is formed in the second step. Plating is applied to the outer peripheral surface of the child piece holder, and in the third step, the plating layer is ground to a diameter that exposes the protrusion.
In the fourth step, the commutator pieces are brazed onto each plating layer remaining on the outer peripheral surface of the commutator piece holder. As a result, the commutator of the first invention is manufactured.

[Example] Hereinafter, an example in which the present invention is embodied in a commutator of a starter motor of a vehicle will be described with reference to the drawings.

FIG. 1 shows a partial cross section of the commutator 10 of this embodiment, and the second
The manufacturing process is shown in FIGS.

First, as shown in FIG. 2, a cylindrical commutator piece holder 12 having protrusions 11 extending at predetermined equal intervals in the axial direction on the outer peripheral surface is formed by firing ceramic. Cheating. Next, as shown in FIG. 3, a plating layer 13 of nickel or the like having a thickness of several microns to several tens of microns is placed on the outer peripheral surface of the commutator piece holder 12 by chemical plating.

Then, as shown in FIG. 4, the plating layer 13 on the outer peripheral surface of the commutator piece holder 12 is ground until the diameter becomes such that the protrusion 11 of the commutator piece holder 12 is exposed.

Thereafter, as shown in FIG. 5, commutator segments (segments) 14 are brazed onto each plating layer 13 remaining on the outer peripheral surface of the commutator segment holder 12. Positioning when brazing in a separated state is as follows:
This is done by providing (pulling, etc.) five concavities and convexities on the commutator piece holder 12 and the rectifying strips 14 so that they fit into each other.

As a result, as shown in FIG. 1, a commutator piece holder 12 made of a cylindrical ceramic having protrusions 11 extending at predetermined intervals in the axial direction of the outer peripheral surface, and a commutator piece holder 12, A commutator 10 is manufactured, which includes a plating layer 13 formed on the outer peripheral surface of the body 12 and insulated and separated by the protrusion 11, and a commutator piece 14 brazed onto the plating layer 13. This commutator is then incorporated into a starter motor, and the commutator is rotated when the motor is in use. At this time, the joint between the commutator piece holder 12 and the plating layer 13 made of ceramic,
Sufficient bonding force is ensured at the bonded portion between the plating layer 13 and the commutator piece 14 by brazing.

As described above, in this embodiment, the commutator piece holder 12 is made of cylindrical ceramic and has protrusions 11 extending at predetermined intervals in the axial direction of the outer peripheral surface (in the first step). 〉, the outer peripheral surface of the commutator piece holder 12 is plated (second step), and the plating layer 1 is coated until the diameter of the protrusion 11 is exposed.
3 is ground, and commutator pieces 14 are brazed onto each of the plating holes 13 remaining on the outer circumferential surface of the commutator piece holder 12 (fourth process) to manufacture the commutator 10. As a result, the commutator piece holder 12 made of ceramic has the protrusion 1
1 is formed, and is not easily affected by the shrinkage of the commutator piece holder 12 during the firing process. Since it does not have a shape that bites in (reverse taper, one-piece shape), it can be easily manufactured. Further, the process for insulating and separating each commutator piece 14 only requires outer periphery grinding.

It should be noted that the present invention is not limited to the above-mentioned embodiments.
4, that is, from the state shown in FIG. 4, it may be manufactured as follows. As shown in FIG. 6, a cylindrical material 15 having a protruding connecting portion 15a and a commutator piece is shaped by cold forging (1), and this is inserted into the outer periphery of the ceramic commutator piece holder 12. After that, it is brazed and the protruding connecting portion 15a of the cylindrical member 15 is ground. the result,
As shown in FIG. 1, the cylindrical material 15 is separated into commutator segments. By doing so, the commutator pieces 14 can be easily positioned.

[Effects of the Invention] As detailed above, according to the present invention, an excellent effect is achieved in that the ceramic commutator piece holder can be made into a structure that is easy to manufacture.

[Brief explanation of drawings]

Fig. 1 is a partial sectional view of the commutator of the example, Fig. 2 is a perspective view showing the commutator manufacturing process, Fig. 3 is a perspective view showing the commutator manufacturing process, and Fig. 4 is a perspective view showing the commutator manufacturing process. A perspective view showing the manufacturing process,
FIG. 5 is a perspective view showing a process for manufacturing a commutator, FIG. 6 is a perspective view showing a process for manufacturing another example of a commutator, and FIG. 7 is a diagram for explaining the prior art. 11 is a protrusion, 12 is a commutator piece holder, 13 is a plating layer,
14 is a commutator piece.

Claims (1)

[Scope of Claims] 1. A commutator piece holder made of cylindrical ceramic and having protrusions extending at predetermined intervals in the axial direction of the outer circumferential surface; and an outer circumferential surface of the commutator piece holder. A commutator comprising: a plated layer formed on the plate and insulated by the protrusion; and a commutator piece brazed onto the plated layer. 2. A first step of forming a commutator piece holder made of cylindrical ceramic having protrusions extending at predetermined intervals in the axial direction of the outer peripheral surface; and an outer peripheral surface of the commutator piece holder. a second step of plating the plating layer; a third step of grinding the plating layer until the diameter of the protrusion is exposed; and a third step of grinding the plating layer to a diameter that exposes the protrusion; and placing a commutator piece on each plating layer remaining on the outer peripheral surface of the commutator piece holder. A method for manufacturing a commutator, which includes a fourth step of brazing.