JPS5833783B2 - Katsupugatamtetsushinden Kishinoseizouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a coreless morph cup-shaped coreless armature, which involves injecting resin under pressure and heat into a molding die to harden the armature windings in close contact with each other. The aim is to manufacture high-quality armatures by

As shown in FIGS. 1 and 2, a conventional wire-wound iron-core coil is manufactured by winding and shaping a predetermined number of coil bundles 1' using a winding jig (not shown). The coil bundle group 1 (inside the mold in the state shown in Figure 1) and the commutator mold 3 were assembled with the required number of coils arranged around the outer circumference of the lower part of the casting mold 2 at equal pitches. Commutator segment 4, shaft 5
Insert and cover with casting mold upper 6.

Thereafter, a liquid resin 1 such as epoxy resin with excellent adhesion to the coil, electrical and mechanical properties is placed in a slot 6 on the casting mold.
Inject from a.

In addition, 8 is a seal ring that keeps the space between the top and bottom of the casting mold airtight, 9
is a rubber ring added to the lower part of the casting mold 2 to prevent resin from flowing into the shaft 5.

The mold into which the resin has been injected as described above is held in hot air heating for a predetermined period of time to completely cure the liquid resin.

After that, the mold was removed and the armature was made into a rigid body made of resin.

However, this method requires several hours for the resin injection process and heat curing process, and in order to increase the production volume, a large number of molds are required due to the batch-type production system.

Moreover, the complexity of the process was unavoidable, which was a major obstacle to mass production.

Therefore, the following method is available as a short-time processing method using resin molding to make the coil an integral rigid body.

That is, the molding material that has been processed to a semi-hardened state (B stage) is melted by heating and pressure, and at the same time, it is instantaneously injected under pressure into the mold into which the coil is inserted.

This method is generally called transfer molding or injection molding.

However, in the case of a cup-shaped wire-wound iron-core coil armature that is the subject of resin molding, its electrical design has an ultra-thin structure, so the coil should be completely embedded in the molded resin. Even after resin molding, a portion of the armature surface was usually exposed.

As a result, the coil parts exposed on the molded resin surface may be lifted off the armature surface due to centrifugal force or vibration caused by high-speed rotation when the armature is used, or the exposed coil parts may As a result, it became impossible to maintain the dimensional accuracy required for the armature, and this caused electrical failure.

In addition, the coil wire diameter of cup-type ironless core armatures for small motors is usually around 0.05 to 0.2 mmφ, so if resin is injected with great pressure, the coil may bend or in extreme cases. Armatures could only be manufactured that would not rotate normally due to short circuits between the coils or even disconnection of the coils.

As described above, the present invention eliminates the exposure of the coil to the surface of the molded product that occurs during resin molding of a cup-shaped wire-wound iron-core coil, and also eliminates curvature of the coil, short-circuit between coils,
The present invention provides a method for manufacturing a resin-molded cup-shaped iron-core armature that does not cause wire breakage and has sufficient reliability in terms of quality.

The present invention will be explained below with reference to FIG.

A predetermined number of coil bundles made by winding a predetermined number of self-fused electric wires using a winding jig are arranged at equal pitches on a shaping jig, and the above-mentioned coil bundle groups are shaped as a single unit and fixed between the coil bundles and between the coils. .

The state of the coil bundle group after shaping is as shown in FIG. 1 above.

When shaping a coil, there are two main methods: applying electricity to the coil and using the Joule heat generated within the coil, and applying heat from the outside, but the former is preferable when the coil wire diameter is thick.

In this shaping process, the shaping mold is modified to apply a pressure of several hundred grams to several kilograms to the coil bundle, which is a collection of coils running in parallel, and to both coil end portions (P section and Q section) where the coil bundles overlap. The wires should be bent and intertwined with each other to the extent that the insulation coating of the wires is not destroyed, and the self-bonding coating applied to the wires should be completely melted so that the coils at the coil ends and between the coil bundles It is necessary to firmly fix the

In addition, the crossing angle θ when the coil bundles overlap each other is not 0 degrees or 90i, but is about 10 degrees to 60 degrees, which reduces the movement of the forming dark line.

Next, the connection wire of the coil bundle group 1 fixed by shaping to the commutator is connected to the commutator segment 4, and the coil bundle group 1 is inserted into the lower mold 11 together with the shaft 5 and the one shear 10 for preventing resin from flowing into the shaft.

Furthermore, after covering the molding die middle 12 and the molding die top 13 to lock the armature in the molding die, the molding material 15 is passed through the gate port 14 attached to the molding die top 13. is melted by heating and pressurizing, and at the same time, it is instantaneously injected under pressure.

After that, hold it as it is for several minutes, and after the resin has hardened, take out the armature made rigid by the resin.

The process is now complete. The outer circumference under the molding die to prevent the coil from curving should be the same as the inner diameter of the coil after shaping, and the inner diameter inside the molding die should be slightly thicker than the outer diameter of the coil after shaping. It is desirable to provide a uniform gap between the coil and the molding die so that resin can be injected smoothly.

Further, better results can be obtained by providing a large number of gate ports evenly around the outer periphery of the bottom of the cup, or by forming a ring.

On the other hand, the space factor of the coil in the P section and the Q section of the coil bundle group after the completion of shaping (the ratio of the coil inserted into the space formed by the molding die), the curved short circuit, and the disconnection of the coil after the completion of shaping. The good product rate excluding defective armature products is the 4th
As shown in the figure, the non-defective product rate rapidly improves when the space factor reaches 10 to 15 percent.

On the other hand, the temperature of the molding die and the temperature of the resin injected during molding are
It is desirable that the temperature be below the softening temperature of resins such as self-bonding coatings and adhesives for fixing coils.

Further, the dart opening must be located at the P portion, that is, the bottom outer periphery of the single-pull type armature, where the coils overlap and are firmly fixed in the shaping process using heat and pressure.

As described above, in the present invention, the coil bundle group is integrally shaped and completely fixed using heat and pressure, and then inserted into the molding mold along with the shaft, commutator, etc., and the molding resin is pressurized and heated. This method is used to manufacture armatures by instantaneously injecting and curing in a short time, and has the following effects.

(1) When conventional pressure casting is used, air bubbles remain in the mold and the resin does not rotate completely, leaving bubble marks everywhere on the product, and the strength of the product varies widely. When used in the armature of a rotating motor, there will be no problem of windage damage, and in severe cases, the armature will crack and break. (2) The molding resin used in the manufacturing method of the present invention has a molecular weight similar to that of the casting resin. Since it is larger than the conventional one, the shaft part,
There is no need to use a rubber seal ring at the connection part of the mold, and it is sufficient to use only a resin inflow prevention washer at the shaft part.

In addition, if a rubber ring is used for the shaft as in the past, the rubber deteriorates due to heat and the curing accelerator added to the casting resin, causing the rubber to wear, crack, or form holes. The bottom of the cup-shaped armature is uneven, so if you hold the armature on that part, the armature will vibrate, and in severe cases, the contact between the commutator and brushes will not be smooth, causing rotational problems. There was a problem, but that problem will no longer exist.

(3) In the case of casting, the excess resin at the injection port is cured together with the product, so after removing the armature from the mold, a large amount of resin is removed from the injection port. Although it takes time and the appearance is unsightly, in the case of the manufacturing method of the present invention, the gate opening can be made very small due to pressurized injection, and due to the structure, the armature of the product and the resin at the gate opening are taken out separately. It is possible to

In addition, the gate opening is provided so that the resin flows into the bottom of the cup where the coil bundle is N from the outside in a direction perpendicular to the 1st axis, so the coil is pressed against the inner circumference and is not exposed on the outer circumference. Fully covered with resin, it has strong mechanical strength, and since the coil follows the inner mold, there is no eccentricity of the armature coil with respect to the shaft, and there is little unbalance in rotation.

Also, since the resin flows in from the part where the coils overlap,
Sufficient quality reliability can be obtained without causing deformation of the coil, short circuit between coils, or disconnection.

(4) According to the manufacturing method of the present invention, the resin is injected under pressure and heat for molding, so it is possible to manufacture the armature in a short time, and furthermore, it is possible to grind out the product and clean the mold in a short time. It can be done.

Therefore, in the past, even if several dozen molds were made, only 20 molds were made in a day.
Previously, only 0 to 300 armatures could be made, but according to the present invention, if one mold with about 20 cavities is available, it is possible to manufacture about 3,000 armatures in a day. In addition, since it is pressure molded, there will be no defects around the resin, the product dimensions are constant, and the variation in quality is very small, making it possible to provide a high quality armature.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a coil bundle group after insertion into a conventional casting mold or after completion of the shaping process of the present invention, and Figure 2 is a cross-sectional view (3) inside the casting mold in which the conventional manufacturing method is carried out. , Fig. 3 is a cross-sectional view of the inside of the mold for carrying out the manufacturing method of the present invention, and Fig. 4 shows the coil wire area ratio of the cup opening and bottom after completion of shaping and the coil wire area ratio after completion of molding in the production method of the present invention. FIG. 3 is a characteristic diagram showing a good product rate of an armature. 1... Coil bundle group, 3... Commutator segment, 5... Shaft, 11, 12, 13.
...Molding mold, 14...Gate opening, 1
5...Molding material.

Claims (1)

[Claims] 1. After arranging a predetermined number of coil bundles made by winding a predetermined number of self-fused wires using a winding jig on a shaping jig, arrange and shape them into a predetermined cup shape using a shaping mold, and then The self-adhesive film fixes between the coil bundles and between the coils,
Next, the parts constituting the armature, such as the armature winding, shaft, and commutator, which have been integrally fixed, are inserted under the molding die, and then placed on top of the molding die. After sealing the armature in the molding die by covering it with A method for manufacturing a cup-shaped coreless armature, in which molding resin is injected under pressure and heat into the mold through a gate provided at a joint with the mold.