JPS6046625B2 - How to fix commutator and armature coil - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a method for fixing commutator pieces and armature coils,
In particular, the present invention relates to a method for fixing a commutator piece and an armature coil, which is suitable for fixing a coil having a relatively large cross-sectional area, such as an armature coil of a vehicle electric motor.

Generally, the method of fixing commutator pieces and armature coils is as follows:
Soldering, TIG welding, and electrical resistance thermocompression bonding All of these methods are unsuitable for fixing armature coils with relatively large cross-sectional areas because of low reliability in mechanical strength.

When fixing the commutator pieces to the armature coil, make sure that the commutator pieces do not cause dielectric breakdown due to heat, and that the armature coil has enough adhesion strength to prevent it from popping out from the riser part during motor operation. Furthermore, it is required that the contact resistance of the fixed portion be small. Of course, monitoring means to ensure the quality of whether or not these fixings are completed, that is, to improve reliability, is also an important element. For example, the soldering method described above is common because it provides a relatively reliable bonding force, but high melting point solder may cause dielectric breakdown due to heat,
Since the solder strength decreases at high temperatures, it is not suitable for electric motors operated under high temperature conditions, and there is a problem of solder scattering, resulting in low reliability. Furthermore, using high temperature welding such as TIG welding causes deterioration of the mica insulation between commutator pieces or risers, and in the case of integrally molded commutators, there is a problem of carbonization of the molding material, resulting in extremely low reliability. . The crimping method using electrical resistance heating is ideal for fixing thin wire coils, but because the current is applied only once, round wires with a large cross-sectional area or rectangular wire coils are difficult to apply through the energizing cycle or energizing. Even if the current is increased, the welding deformation necessary for fixing cannot be obtained and sufficient fixing force cannot be obtained.

This has the disadvantage that even if an attempt is made to fix it with a large current, only the local area in contact with the electrode is rapidly deformed, and the heating temperature becomes high, and in the case of an integrally molded commutator, the molding material carbonizes and dielectric breakdown occurs. ing. On the other hand, electrical resistance brazing is generally used for fixing rectangular wires, but requires a filler metal, and like the resistance thermocompression bonding described above, the filler metal must be melted, resulting in a large current, and requires TIG welding or resistance heating. Similar to crimping, changes in mica and integrally molded commutators have the disadvantages of carbonization of the molding material and reduced strength between the commutator pieces and the mold. For this reason, it is particularly unsuitable for bonding to a molded commutator using the integral molding method.
Furthermore, in both cases, the only way to guarantee quality was to control the conditions at the time of adhesion, making it difficult to guarantee highly reliable quality. An object of the present invention is to provide a method for fixing commutator pieces and armature coils that is suitable for fixing armature coils having a relatively large cross-sectional area. Another object of the present invention is to provide a method for fixing commutator pieces and armature coils that can prevent deterioration of the insulation interposed between the commutator pieces.

Another object of the present invention is to provide a method for fixing commutator pieces to armature coils, which facilitates quality assurance of the commutator. The present invention relates to a fixing method suitable for fixing an armature coil using a round wire or a rectangular wire having a relatively large cross-sectional area to a commutator piece (including a riser part).

It was confirmed that the conventional armature coil deformed rapidly locally only near the electrode contact, and the coil located at the bottom of the riser did not deform much, so it was not possible to obtain sufficient adhesion force. A commutator piece that prevents variations in the thermocompression bonding conditions applied to the coil by making it uniform, and prevents abnormal overheating near the coil by slowing down the deformation speed during coil compression. and to provide a method for fixing armature coils. This reduces the thermal effect on the commutator piece insulators, uniformly deforms down to the lower coil, and ensures the commutator has sufficient adhesion even under severe operating conditions.
The present invention will be described below based on the case of a molded commutator. In FIGS. 1 and 2, the commutator includes a metal bush 1 press-fitted into a shaft, commutator pieces 2 arranged radially at equal intervals, and both and a molding material 3 filled in the spaces between the commutator pieces.

The commutator piece is formed into a substantially L shape and includes a riser 2A having an armature coil insertion groove 4. Note that this groove 4 has a width dimension of the coil to be inserted so as to completely confine the coil when it is fixed. The armature coils 5 of the motor are inserted into the grooves 4 of the riser 2A (7) of the commutator having such a structure, in a radial direction overlapping each other as shown in FIG. Thereafter, the armature coil 5 is electrically heated by the first electrode 6 arranged around the commutator piece 2r and the second electrode 7 arranged around the groove 4.
is welded to riser 2A. Note that the electrode 7 may be brought into contact with the coil itself. Next, the situation will be explained with reference to FIGS. 4 and 5. The respective electrodes 6 and 7 are connected to the secondary coil 9 of the transformer 8, and the primary coil 10 is connected to the power source AC via the controller 11. ing. The displacement position of the second electrode 7 is detected by the potentiometer 12, and the current position of the potentiometer 12 is set to 0 displacement at the same time as the displacement meter 14 starts operating according to a signal from the toroidal coil 13. However, the controller 11 is configured to be controlled when the subsequent displacement voltage reaches a preset level. That is, first the electrodes 6 and 7 are set, and the second electrode 7 is
A load of about 9 is applied, and the start signal S shown in FIG.
When the current is turned on, current is supplied from the controller 11 to the transformer 8 in synchronization with this. Then, the transformer 8 is activated and the electrode 7 is heated with a current of H for the first heating time T1, and then the rest time is 0FF1.
, and is heated by electricity again at T2, and then heated by electricity by repeating T2 and T3. In this process, the position of the electrode 7 (
Amount of sinking) Figure 5 CH is 11,1 after the pause time.
2, L, and enters the displacement meter 14 at a certain level (when the energization signal is caught by the toroidal coil 13, the O level is set, and the displacement position is measured based on this. At this time, the displacement meter The proper position is set and compared with the displacement position measured by the potentiometer 12, and when the amount of displacement due to energization reaches the proper displacement position, the controller outputs the energization stop signal ST. Send to 11,
This is to stop energization. This makes it possible to always maintain a constant displacement position (amount of depression) of the electrode. Of course, the above-mentioned energization heating time T1 pause time 0FF1 current amount H is arbitrary, and there is no particular restriction on the number of times of repeated energization. As shown in FIGS. 6 and 7, the commutator obtained by the above method has a concave electrode abutting portion and necessarily has a predetermined crimping amount D. Here, the relationship between the electrodes 6 and 7, the rectifier bar 2, and the riser 2A will be explained with reference to FIGS. 8 and 9. Since the first electrode 6 only has the role of a current contact, However, the second electrode 7 is important for fixing the armature coil 5 to the riser part 2A, and the diameter b of the tip corresponding to the specified displacement position is at least It is set to be smaller than the riser segment width a, larger than the armature coil width c, and smaller than the riser width d. The second electrode 7 may be located at any position where the armature coil 5 can be fixed, but theoretically the center of the riser is most suitable. From the above, for example, in the case of conventional one-shot energization, of course a large current and a large load are required, and in addition, since the electrode is deformed in a short time, only the electrode contact part (upper coil part) is extremely deformed.
It is difficult to uniformly heat and deform the lower coil.
Furthermore, since the degree of deformation is rapid (Fig. 10 1), it was difficult to control the amount of crimping at a constant level. However, according to the present invention, the current is gradually increased by slope control, and then the current is crimped in a number of pulses. By repeatedly energizing at a low current over several cycles, the deformation speed can be made gentle (
Figure 10 ■).

Therefore, the heat effect on the mold resin and the car can be reduced, and even the lower coil can be heated evenly, and the deformation speed is very slow, which has the great advantage of making it easy to control the amount of deformation (the amount of crimping) that affects crimping. have In other words, this deformation amount (crimping amount) is controlled to a constant crimping amount using a potentiometer and a displacement meter equipped with a feedback mechanism, and by using this energization method together with the monitoring device using the displacement meter described above, reliability can be improved. A highly adhesive part can be obtained. FIG. 11 shows an example of the results of measuring the amount of crimping obtained by the present invention. Since the bonded joint is heated at a low current, the maximum heating temperature is low, and carbonization of the mold can be minimized, and the bottom of the riser Because there is sufficient temperature and time for the lower coil to deform, the deformation is uniform. Therefore, the amount of crimping can be minutely controlled and sufficient adhesion force can be obtained. Furthermore, since the carbonization of the insulator can be minimized, there is no reduction in the adhesion strength between the commutator pieces and the molding material, and it is possible to fix an armature coil with a large cross-sectional area.

Furthermore, since the current is low, the life of the electrodes is extended, and since the load is low, there is less damage and a highly reliable commutator can be obtained. In this embodiment, the electrical resistance thermocompression bonding of the commutator pieces and the armature coil has been described, but the present invention can also be used in the case of electrical resistance brazing.

As described above, according to the present invention, it is possible to use an armature coil having a large cross-sectional area, and it is possible to provide a fixing method with little insulation deterioration and sufficient fixing force.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a front view of the commutator, FIG. 2 is a sectional view of FIG. 1, FIG. 3 is a perspective view of the commutator before welding, and FIG. A circuit connection diagram in crimp welding, FIG. 5 is a crimp welding process waveform diagram, FIG. 6 is a perspective view of the commutator after welding, FIG. 7 is a partial side view of FIG. 6,
8 and 9 are dimensional diagrams of commutator pieces and electrodes, FIG. 10 is a comparison diagram of the amount of crimping versus time, and FIG. 11 is a waveform chart showing the actual measured value of the amount of crimping versus time. Explanation of symbols, 2... Commutator piece, 2A... Riser, 5... Armature coil, 6...
First electrode, 7... Second electrode, 13...
Toroidal coil, 14...Displacement meter.

Claims (1)

[Claims] 1. A method for fixing a commutator and an armature coil, in which a current-carrying electrode is brought into contact with the commutator piece and the armature coil mounting position from the radial direction, and the current is heated and bonded while controlling the current flowing through the electrode.
An intermittent heating current is supplied with an energization pause time between a first electrode that is in contact with the rectifying piece and a second electrode that is paired with the electrode and is arranged at a position corresponding to the electric coil fixed part. , a method for fixing a commutator and armature coil, characterized by fixing the commutator piece and armature coil by welding. 2. In claim 1, the electrical reference value obtained by the first electrode and the electrically converted value of the sinking amount of the second electrode are compared using a displacement meter, A method for fixing a commutator and armature coil, which is characterized by fixing the commutator and armature coil by welding while controlling the supplied current according to the output of the displacement meter.