JPS5947544B2 - Manufacturing method of iron-free armature - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a cup-shaped ironless armature.

To manufacture a conventional cup-shaped coreless armature, the armature winding is first wound with a winding machine to form a cup shape, and this winding is inserted into a shaping mold and shaped into a predetermined shape.

Thereafter, the lead wire of the winding to the commutator is connected to the riser of the commutator to which the shaft is attached, and the armature winding assembly is completed.

Next, the winding assembly is placed in a casting mold, and a resin solution such as epoxy is injected under reduced pressure and cured by heating to obtain a coreless armature.

However, in this method, the solution viscosity is very low and requires a very long time (more than 1 hour) for heating and curing, so many molds are required, a heating furnace is also required, and furthermore, resin injection is required. Otherwise, it is not suitable for mass production because it takes a lot of work time to remove particles, etc. Also, because it is a vacuum casting process, there are areas where the resin is not injected, such as air bubbles, which weakens the strength of the armature and causes quality problems. Ta.

As a means to improve the conventional method, the armature winding assembly is inserted into a mold, and semi-cured resin is heated from the outside by a gate provided at the cup opening or bottom outer periphery of the cup-shaped armature. A method of pressurized injection has been proposed.

However, with this method, a large number of molds can be assembled into small pieces and injected all at once from one pot, and the curing time is only a few minutes, so mass production is much improved compared to the above-mentioned method, but the resin is Because the injection is carried out under pressure, if the wire diameter of the armature winding is small, it will not be able to withstand the resin injection pressure and the winding will be deformed, or the lead wires to the commutator may break, or the windings may become stuck together. This caused problems such as short circuits.

The present invention solves all the problems of the above conventional methods, and will be explained below with reference to the accompanying drawings.

First, as shown in FIG. 1, an armature winding 1 is provided, which includes a predetermined number of coil bundles made by winding a predetermined number of self-fused wires using a winding jig.

Note that 2 is a lead wire connected to the commutator.

Next, as shown in FIG. 2, the armature winding 1 is inserted into the heated A mold 3 together with the commutator 5 and the shaft 6 connected to the lead wire 2, and the A stage (raw resin) is placed on top of it. A resin plate 4 made of a thermosetting resin kneaded together with additives into a disc shape is placed thereon, and a heated mold B 7 is inserted from above.

As the mold B 1 is inserted, the root winding 1 is shaped into a predetermined size.

Next, before the B mold 1 is completely inserted to the predetermined position, the C mold 8 is pushed up from below to shape the coil end portion of the cup opening, and the B mold 7 is further inserted to the predetermined position. do.

During this shaping, a press-fit bushing 7 made of a heat-resistant resin material with poor thermal conductivity is placed on the surface of the mold B 7 that is in contact with the resin plate 4.
a is provided, the resin plate 4 will not be heated and hardened before the shaping is completed and will not flow out of the mold.

After the shaping is almost completed, the resin of the resin plate 4 is melted and filled into the space formed by the molds A, B, and C while sliding on the armature winding.

Hold the above condition for several minutes, and after the resin has hardened,
The B mold 7 is removed and a completed armature as shown in FIG. 3 is taken out.

Note that 9 is a protective cap provided to prevent the resin from adhering to the undercut portion and outer periphery of the commutator.

Although the above embodiments used A-stage resin, B-stage (semi-cured) resin may be used to shorten the curing time.

Of course, in order to further shorten the length, the resin plate may be preheated.

Furthermore, in the above embodiment, the shaping of the armature winding 1 and the injection of resin were carried out simultaneously in the same mold, but it goes without saying that the shaping of the armature winding 1 and the injection of resin may be carried out in separate molds, and the shaft etc. may be inserted and fixed after the resin has hardened.

Another embodiment of the present invention will be described with reference to FIG. 3. A press-fit bushing 3a is provided on the upper outer periphery of the A mold 3, a resin plate 4 is placed on it, and the armature winding 1st class armature is placed on top of the press-fit bushing 3a. The parts constituting the mold are inserted, and the same steps as in the previous embodiment such as the mold B are carried out.

As described above, a disc made of thermosetting resin is provided at the bottom of the cup of a winding shaping mold, and a press-fit bushing with low thermal conductivity is provided on the mold surface in contact with the resin plate for heating. The armature winding with the shaft commutator attached is inserted into the mold and the mold is tightened from above and below to shape the winding. After the shaping is almost complete, the heated and softened resin flows into the winding. Since it hardens, it becomes possible to take out the armature that has been hardened with resin by opening the mold.

In the above embodiments, the mold surface in contact with the resin plate was made of a material with low thermal conductivity, but the same effect can be obtained even if the same material is used in the area indicated by the dotted line in Figure 2.

As is clear from the above embodiments, the present invention provides the following effects.

1. Heat fluidization of the resin and shaping of the winding wire can be done in the same mold, and the resin fixation of the winding wire can be done at the same time, making it very efficient.

Furthermore, equipment and mold prices will also be significantly lower.

2 In the conventional case, resin remained in runners, pots, etc., and the resin used in the product was 20 to 30%, but in the case of the present invention, the amount of resin that is unnecessary is zero.

This reduces the cost of the resin. 3. Resin is injected into the armature winding at a pressure slightly higher than normal pressure, wetting it and sliding it around, and the winding is fixed with the resin in a short time, making it easy to work and preventing shorts, breaks, and bends in the armature winding. No total heat is generated.

4. Since the conventional 2-3 steps are completed in 1 step, loss is greatly reduced and quality is stable.

5. Since A-stage (raw resin) can be used as the resin material, it has good affinity with the self-adhesive coating or insulation coating applied to the electric wire, and the resin and the electric wire adhere well, making it suitable for electrical appliances. The child becomes strong.

6. Heating applied to the armature winding can be completed only once, reducing deterioration of the wire due to heating.

7. Since the resin does not flow out through the mold before the mold is closed, no air bubbles are generated.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an armature winding used in the armature of the present invention, FIG. 2 is a cross-sectional view showing a method for manufacturing the armature of the present invention, and FIG. 3 is a diagram showing another embodiment of the present invention. FIG. 4 is a sectional view showing the manufacturing method, and is a sectional view of a cup-shaped armature manufactured according to the present invention. 1... Armature winding, 4... Resin plate, 5
... Commutator, 3. γ, 8...Mold, 3
a, 7a...Press-fit bushing.

Claims (1)

[Scope of Claims] 1. The armature winding is wound a predetermined number of times to form a predetermined shape, and parts constituting the armature, including the winding and commutator, and a molding resin member that is solid at room temperature are heated in a mold. A mold is further inserted from above, and the resin of the molding resin member is heated and injected into the space formed by this mold, and the resin is cured to form the armature winding. A method for manufacturing a fixed ironless armature, characterized in that a press-fit bushing with low thermal conductivity is provided in a part of the mold that contacts the molding resin member. 2. The method of manufacturing a coreless armature according to claim 1, wherein the press-fit bushing is provided so as to be in contact with an armature component near the molding resin member.