JPH0145310B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of joining an armature coil and a commutator in a rotating electric machine.

First, a conventional device of this kind will be explained using a starter motor for an internal combustion engine as shown in FIGS. 1 and 2 as an example. In the figure, 1 is a rotating shaft, 2 is an armature core that is fixed to the rotating shaft 1 and has a plurality of slots (not shown) formed on its outer periphery, and 3 is an armature core around which a field coil 4 is wound. 7 is a rear bracket supporting one side of the rotating shaft 1; 8 is a front bracket (not shown), and the yoke 3 and rear bracket 7 are fastened together. The through bolts 9 are a plurality of armature coils which are inserted into each slot of the field core 2 in an overlapping manner, for example, in two layers, each having an outlet 9a. Reference numeral 10 indicates a plurality of commutator pieces 11 made of copper material and each of these commutator pieces 11.
Insulating member 1 such as mode material that insulates and holds each
2, which is fitted onto the rotating shaft 1. As shown in FIG. 2, this commutator 10 includes a commutator piece portion 11a, which is an extension of the commutator piece 11, in which a joint groove 11b is formed into which the outlet portion 9a of the armature coil 9 is inserted. Mold material part 12
An armature coil support portion 13 is formed by a. These commutator 10, armature core 2, and armature coil 9 constitute a rotor. A brush holder 14 is fixed to the rear bracket 7 and holds a brush 15 that is in sliding contact with the commutator piece 11, and a pinion gear 16, not shown, is fixed to the other side of the rotating shaft 1 and meshes with a ring gear of the engine. The electromagnetic switch 17 that operates for this purpose is solder for electrically connecting the commutator piece portion 11a and the outlet portion 9a of the armature coil 9.

Next, the operation of the conventional device will be described. First, when starting the engine, when the electromagnetic switch 16 is operated, the pinion gear is moved in the axial direction and meshes with the ring gear. Therefore, the electromagnetic switch 16
When the switch part is closed and the armature coil 9 is energized by the power supply from the field coil 4 and the brush 15 through the commutator 10, rotational torque is generated in the rotor and the rotating shaft 1 is rotated, so that the ring gear is rotated. is rotated via a pinion gear to start the engine.

Here, the electrical connection between the armature coil 9 and the commutator 10 is made by aligning the two outlet parts 9a of the armature coil 9 and inserting them into the joining grooves 11b of the commutator piece part 11a, and then joining them with solder 17. is being carried out. However, when the armature current is applied from the power source to the armature coil 9 through the brushes 15 and the commutator 10, the rotor rotates, so that the connection between the outlet part 9a of the armature coil 9 and the commutator piece part 11a A centrifugal force generated by the rotation of the rotor acts on the armature coil 9, and the armature coil 9 tends to pop out. At the same time, the joint is heated by the synergistic heat such as the Joule heat generated by the armature current, the frictional heat generated between the brush 15 and the commutator piece 11, and the high heat from the engine.
This heat allows the solder 17 to melt.

Therefore, due to the low bonding strength itself by soldering and the above-mentioned conditions, the bonding strength between the outlet portion 9a of the armature coil 9 and the commutator piece 11 at the bonded portion is significantly reduced. Eventually, it will cause a disconnection accident and will no longer function as a starting motor. This is particularly noticeable in engines where the rotor is rotated at high speed by increasing the armature current for the purpose of improving engine startability or the like.

To solve this problem, the commutator piece 11
In other words, it is conceivable to increase the joint strength by increasing the radial dimension of the armature coil support part 1 and deepening the joint groove 11b, but since the support part 13 becomes large, the commutator piece 11 is formed. A large amount of copper material, molding material, and solder 17 are required, resulting in the disadvantage that the device becomes expensive and large.

This invention not only solves the above-mentioned drawbacks, but also improves the radial dimension of the commutator pieces by joining the armature coil and the commutator pieces by a hard soldering method that is superior to soldering. The present invention provides a method for joining an armature coil and a commutator in a rotating electrical machine, with the purpose of shortening the length of the armature coil and commutator piece and greatly improving the joining strength between the armature coil and the commutator piece.

The embodiment shown in FIGS. 3 and 4 will be described below. In the figure, 11c is a commutator piece portion with a shortened radial dimension, and 11d is this commutator piece portion 1.
1c, the depth of which is shallow, and the opening 9a of the armature coil 9 in the conventional device.
It is not something to be inserted, but to maintain the joining position of the commutator piece 11 and the outlet part 9a of the armature coil 9. Note that the radial dimension of the armature coil support portion 13 is shortened by shortening the commutator piece portion 11c. 18 is a hard brazing material used for joining the outlet portions 9a of each armature coil 9;
9 is one of the above-mentioned outlet portions 9a and the commutator piece portion 11c.
A hard brazing material used for joining with other materials, and these connections are made by hard soldering. 21 is a welding means using a hard soldering method, which connects a power source 21a and positive and negative electrodes 21.
b, 21c.

The operation of the device constructed in this way is the same as that of the conventional device, so the explanation will be omitted, and the method of joining the armature coil 9 and commutator piece 11 will be explained. First, each outlet part 9a is supported by a jig or the like, and then the commutator 10 is inserted into the rotating shaft 1 so that the joint groove 11d of the commutator piece part 11c is connected to the armature coil 9. Apply a certain amount of pressure to one of the outlet parts 9a and move it to a position where it abuts. Thus, the commutator piece portion 11c and one outlet portion 9 of the armature coil 9
a are in sufficient contact with each other and the contact resistance is small, when the one outlet part 9a and the commutator piece part 11c
A brazing material 19 such as phosphor copper brazing material is inserted into the joining portion, that is, the joining groove 11d, and a phosphor copper brazing material 18 is also inserted between one outlet 9a and the other outlet 9a. Insert the other outlet part 9a and commutator piece part 1.
Positive and negative electrodes 21b and 21 each made of carbon or the like on 1c.
Bring c into contact. In this state, each electrode 21b, 21
A predetermined voltage from the power supply 21a is applied between the openings 9a and 9c through the positive and negative electrodes 21b and 21c.
If a large current is applied to the commutator piece 11c, the Joule heat (approximately 800 to 850
The above-mentioned outlet portion 9a and the outlet portion 9
The joint between a and the commutator piece 11c is heated, and this high heat melts the brazing filler metals 18 and 19 and fills the gap between the joints.As a result, the gap between the outlet parts 9a and Outlet portion 9a and commutator piece portion 11
Join c. This joining means is a so-called resistance brazing method using a hard brazing material.

In this way, if the outlet portions 9a and the outlet portions 9a and the commutator piece 11 are bonded using the resistance brazing method, the high heat for the bonding is generated only in the bonded portion, and the commutator The light is not transmitted to the entire molding material 12 that holds the piece 11 and does not have any influence. This means that if a heat source such as gas welding is used that heats the joint and the brazing materials 18 and 19 to a high temperature over a wide range, the entire armature coil 9 and commutator 10 will be heated to a high temperature due to the high heat. , the enamel of the armature coil 9 is peeled off, and the commutator 1
This means that it is possible to prevent the defect that the molding material 12 of 0.0 is thermally expanded and causes the commutator pieces 11 to float, thereby causing loss of function as a commutator. Furthermore, the brush 15 and commutator piece 11 that affect the joint part
The synergistic heat such as frictional heat caused by the armature current flow, high heat from the engine, etc. is at a temperature that is high enough to melt the solder.
8 and 19 have not yet been melted, and even if the centrifugal force of the rotor acts, the joint strength between the joint parts 9a and between the joint parts 9a and the commutator piece 11c is It is fully guaranteed and there will be no disconnection. Furthermore, since the outlet part 9a and the commutator piece part 11c are joined by the soldering method, the joining strength can be greatly improved compared to soldering, and the armature coil support part 13, that is, the Commutator piece part 11
c. The radial dimension of the molded material portion 12b can be shortened, the size of the commutator 10 can be reduced, and the amount of copper in the commutator piece portion 11c and the amount of molded material can be reduced, making the commutator 10 easy and inexpensive to manufacture. It is possible. Furthermore, since the joining groove 11 is filled with hard brazing material, one outlet portion 9a and the commutator piece portion 11
The bonding area between c and the hard brazing material becomes large, and the bonding strength can be increased. Furthermore, it has the effect of simplifying the joining work to hard-solder joints at the same time and shortening the time required.
Further, the joining can be performed by an automatic joining machine without manual work.

As described above, in a device for electrically joining an armature coil and a commutator, the present invention positions one of the openings on the outer periphery of the commutator piece and fills it with molten brazing material. A joining groove of the same shape was provided, and the arms of the armature coil on this joining groove were simultaneously joined between each outlet and between one of the outlets and the commutator piece by hard soldering, so that the diameter of the commutator piece could be reduced. A device with high bonding strength can be obtained without increasing the directional dimension. Furthermore, during the welding process, the welding groove holds the welding position of the lower coil, which prevents the lower coil from falling over and minimizes the negative effects of the heat generated during welding. Since the filler metal is filled into the joint groove, the strength of the joint with the commutator pieces is increased, and the solder metal does not flow into adjacent commutator pieces, preventing the occurrence of short circuits, making the joining work easier. As a result, the time required for the work can be significantly shortened, and other great effects can be obtained.

[Brief explanation of drawings]

Figure 1 is a structural diagram showing a conventional starting motor;
The figure shows a partial front view of the commutator 10 in the device shown in FIG. 1, FIG. 3 is a partial front view of a commutator showing an embodiment of the invention, and FIG. It is a side view which shows the state which joins the child piece part 11c. In the figure, 1 is the rotating shaft, 2 is the rotor core, 4 is the field coil, 5 is the field core, 9 is the armature coil,
9a is an outlet, 10 is a commutator, 11 is a commutator piece,
11a and 11c are rectifier pieces, 11b and 11d are joining grooves, 12 is a molding material, 12a and 12b are molding materials, 13 is an armature coil support part, 15 is a brush, 17 is solder, and 18 and 19 are hard solder. It is a material. Note that the same reference numerals in each figure indicate the same or equivalent parts.

Claims (1)

[Claims] 1. When one of the outlet portions of each armature coil and the commutator piece of the commutator are joined by hard soldering, one of the outlet portions is positioned on the outer periphery of the commutator piece. and a joining groove having a shape that can be filled with molten brazing material, one and the other of the above-mentioned openings are arranged radially overlapping each other on this joining groove, and a hard brazing material is interposed between them. Then, a welding electrode is brought into contact with the commutator piece and the other of the respective outlet parts and energized to harden the parts between each of the outlet parts and between one of the outlet parts and the commutator calf at the same time. A method of joining an armature coil and a commutator in a rotating electrical machine characterized by brazing joining.