JPH0258854B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a coreless armature for use in a coreless motor, and more particularly, to a method of manufacturing a coreless armature in which at least the armature winding portion is integrally made rigid with epoxy resin. It is.

In general, ironless motors take advantage of their extremely quick response and are often used to perform incremental operations, such as serial printers, line printers, magnetic disks, card readers, card punches, fax machines, data recorders, copying machines, etc. Used in automatic welding machines and machine tools, etc.

In view of the increasing precision and performance of the various types of equipment mentioned above, there is a demand for the development of technology for efficiently manufacturing ironless motors with even higher control responsiveness, that is, ironless motors with lower inertia.

The iron coreless motor will be explained based on the drawings. Fig. 1 is a sectional view of a cup-shaped ironless motor using a ironless armature, Fig. 2 is a perspective view showing an unshaped armature winding group, and Fig. 3 is a cup-shaped cup-shaped motor using an unshaped armature winding group. These are perspective views of armature windings, and in these figures, 1 is a group of unshaped armature windings, 1' is a shaped armature winding, 2 is a commutator, 3 is an armature shaft, 4 is a bearing, 5 is a brush, 6 is a magnet, 7 is a bracket, 8
is a thermosetting synthetic resin that seals at least the armature winding 1', supports and insulates it, and forms an integral rigid body.

Next, a conventional manufacturing method of the ironless armature will be explained.

First, as shown in the block diagram of Fig. 4, in the first step, a predetermined number of electric wires having a self-adhesive layer etc. are wound, and then a adhesive layer or adhesive is used between the wires and between the windings. and fix it to form an unshaped armature winding group 1.

In the second step, the armature winding group 1 is shaped into a predetermined shape such as a cup shape or a flat shape using a heated mold, and at the same time, the self-fusing layer or adhesive on the surface of the wire is melted and solidified to shape it. Then, the armature winding 1' is formed.

In a third step, the lead wire of the armature winding 1' and the commutator 2 are electrically connected via the winding end portion on the commutator 2 side, and in a fourth step, the lead wire of the armature winding 1' and the commutator 2 are The armature shaft 3 is fixed by gluing or press-fitting.

In the fifth step, the armature winding 1' is placed on a molding die and sealed with a thermosetting synthetic resin 8 to form a coreless armature.

As described above, in the conventional method for manufacturing a coreless armature, the unshaped armature winding group 1 and the shaped armature winding 1' are pressurized in a heated mold at least multiple times. It's what I needed. That is, the second step of shaping the armature winding group 1 to form the armature winding 1' and the fifth step of sealing the armature winding 1' with the thermosetting synthetic resin 8 are essential. This resulted in an increase in the number of processes.

In addition, when the iron core armature is made into a cup-shaped or flat-plane iron core motor, for example, it is necessary to make at least the armature winding part an ultra-thin structure from the electrical design point of view. The armature winding group 1 must be shaped into an ultra-thin shape using a heated mold, and at this time friction occurs between the wires or windings, resulting in a reduction in the winding space factor, especially in electrical design. Damage or breakage of the insulation coating of the wire occurred at the end of the winding where the wire had a high temperature, resulting in product defects.

Furthermore, in the fifth step of sealing the shaped armature winding 1' using a thermosetting resin (8), the thermosetting resin 8 is usually a molding material based on epoxy resin or unsaturated polyester resin. Since the armature winding 1' is heated, it is usually difficult to withstand the sealing pressure, which results in electrical failures such as breakage of the armature winding or short circuit between layers. Furthermore, even if the electrical failure was avoided, the armature winding 1' was significantly deformed.

Such deformation of the armature winding 1' not only causes a decrease in the torque and rotational speed of the ironless motor, but also impairs the electrical positional relationship with the commutator 2, making it difficult for smooth commutation. However, there were problems such as shortening the life of the brush.

By the way, the ironless armature is used as an ironless motor for various control purposes, and for example, it overlaps with the fields of synchronous motors for speed control and pulse motors for position control, and the fields of application of these motors overlap. There is a strong demand for even higher performance and precision, especially in terms of controllability.

The present invention has been developed based on the above-mentioned viewpoints, and has resulted in the completion of a method for manufacturing iron-core armatures that can efficiently manufacture iron-core armatures with excellent performance.

That is, the present invention provides microcapsules containing a foaming agent that expands in volume at temperatures above the softening point to form microscopic hollow spheres, a synthetic resin having a photopolymerizable functional group, a photopolymerization initiator, and a curing agent. A liquid resin composition is prepared by blending the above with an epoxy resin, and this resin composition is applied to an unshaped armature winding group formed by winding a predetermined number of electric wires to remove the light in the set composition. After photopolymerizing a synthetic resin having a polymerizable functional group by UV irradiation, the microcapsules expand in volume to form microscopic hollow spheres, and the epoxy resin is heated to a temperature higher than the temperature at which the epoxy resin polymerizes and hardens; It is characterized in that at least the armature winding portion is integrally made into a rigid body in a predetermined shape.

More specifically, as shown in the block diagram in FIG. 5, after a predetermined number of wires are wound in the first step, the liquid epoxy resin composition of the present invention is applied to the wire and photopolymerized by UV irradiation. Armature winding group 1 having a resin composition coating film that is solid at room temperature
form. In this case, the resin composition may be applied to the electric wire and wound while being photopolymerized.

Next, in a second step, the armature winding group 1 and the commutator 2 are electrically connected.

Furthermore, in a third step, the armature winding group 1, together with the commutator 2 and the armature shaft 3, is shaped into a predetermined cup-like or flat shape in a heated mold to form the armature winding 1'. At the same time, the microcapsules containing the foaming agent in the resin composition applied to the armature winding group 1 are foamed and expanded to form microscopic hollow spheres, and the epoxy resin is polymerized and hardened to form the electrical equipment. By sealing and supporting and insulating the child winding 1', a coreless armature is manufactured.

Next, the epoxy resin composition used in the present invention will be explained.

That is, the composition is prepared in a liquid form by blending fine capsules, a synthetic resin having a photopolymerizable functional group, a photopolymerization initiator, a curing agent, etc. with an epoxy resin.

The microcapsules containing the blowing agent used in the resin composition include substances that generate gas when heated, such as dinitrilopentane methylenetetramine, azodicarbonamide, toluenesulfonitrile hydrazide, and azoisobutylnitrile, or propane, pentane, The cores are resinous and cycloaliphatic hydrocarbons that do not dissolve microcapsule-forming substances, such as hexane, heptane, petroleum ether, butane, dichloropentane, and cyclopentadiene, and these cores are converted into acrylonitrile-vinylidene chloride polymers, Examples include those encapsulated in capsules made of substances such as MMA-acrylonitrile copolymer, MMA-vinylidene chloride copolymer, polystyrene, polyα-methylstyrene, and polyisobutylene.

In addition, as an epoxy resin, bisphenol A
Diglycidyl ether, alicyclic epoxy, novolak type epoxy, etc. can be used, and liquid ones are particularly preferred. Incidentally, a monoepoxy compound can also be used in combination.

Furthermore, synthetic resins with photopolymerizable functional groups include compounds with polymerizable double bond groups in their molecules, such as acrylic acid or methacrylic acid esters of monohydric alcohols such as methanol and ethanol, and acrylic resins such as ethylene glycol and propylene glycol. Examples include acid or methacrylic acid ester, trimethylolpropane, acrylic acid or methacrylic acid ester of pentaerythritol, N-N'-methylenebisacrylamide, acrylic acid or methacrylic acid amide of N-N'-methylenebisacrylamide, etc. be able to. Further, compounds having a photopolymerizable functional group and a thermally polymerizable functional group such as cinnamic acid glycidyl ester, phenylmaleic acid glycidyl ester, and glycidyl acrylate can also be used.

Furthermore, as the curing agent for the epoxy resin, those that are stable at room temperature, such as BF3 amine complex, cydiandiamide, and imidazoles, are preferable.

As the photopolymerization initiator, compounds commonly used in photopolymerization reactions are used, such as benzophenone, Michler's ketone, anthraquinone, and benzoin alkyl ether. In the present invention, it is desirable to carry out photopolymerization using ultraviolet rays.

Furthermore, fillers, pigments, and the like can be added to the resin composition as necessary.

Next, the present invention will be explained with reference to examples.

Example First, as an epoxy resin, diglycidyl ether of bisphenol A was diluted with 11% butyl glycidyl ether (epoxy equivalent: about 190).
70 parts by weight, 5 parts by weight of BF3 monoethylamine complex as a curing agent, and tetradecamethylene diacrylate as a synthetic resin having a photopolymerizable functional group.
20 parts by weight, benzophenone 5 as a photoinitiator
A liquid resin composition was prepared by adding and mixing 10 parts by weight of an MMA-acrylonitrile copolymer containing isobutane as fine capsules.

In addition, 49 polyurethane insulated wires with a wire diameter of 0.15 mm are used.
A group of electric wires was prepared by laminating and winding the wires on a winding frame with an outer diameter of 19.6 mm so as to form turns and 7 segments.

In the first step in FIG. 5, the electric wire group is dripped and impregnated with the resin composition, and is irradiated with an ultraviolet ray irradiation device at an illumination intensity of 1800 μW/cm ² for 2 minutes, so that the resin composition impregnated into the electric wire group is A synthetic resin having a photopolymerizable functional group was photopolymerized to produce armature winding group 1 having a resin composition coating that is solid at room temperature.

Thereafter, in the second step shown in FIG. 5, the armature winding group 1 and the commutator 2 are electrically connected.

Next, in the third step, the armature shaft 3 together with the armature winding group 1 were placed in a mold that had been heated to 150°C ± 3deg, and the mold was clamped at a speed of about 2 cm/sec. After that, hold the mold for 3 minutes and open the mold to form an inner diameter of 19.5 mm, an outer diameter of 20.8 mm, and a height of
A 30.0mm cup type ironless core armature was manufactured.

Even when this manufacturing method was repeated 50 times under the same conditions, no electrical defects were observed in the resulting product.

In addition, 120 units of the 5 iron core armatures obtained above were
As a result of repeating the thermal shock test five times in which the armature was heated to ℃ and then immediately immersed in a dry ice-MeOH bath whose temperature was adjusted to -40℃, the dimensional change in the outer diameter and height of each armature was less than 1/100 mm. Moreover, no cracks were observed.

Comparative example An electric wire made by laminating and winding a self-bonding polyurethane insulated electric wire with a butyral fusion layer with a wire diameter of 0.15 mm on a winding frame with an outer diameter of 19.6 mm in the same manner as in the example so that there are 49 turns and 7 segments. This wire group was solvent-bonded with acetone in the first step of FIG. 4 to produce armature winding group 1.

In the second step, the winding group 1 is placed in a mold preheated to 150°C ± 3deg, and the mold is clamped at a speed of 2 cm/sec, and the fusion layer on the surface of the wire is melted and solidified, and the wires are A shaped armature winding 1' was obtained by bonding the windings together.

Next, in a third step, the winding 1' and the commutator 2 are electrically connected via the commutator-side winding end portion of the winding 1', and in a fourth step, the commutator 2 and the electric The child shaft 3 was bonded, and then in a fifth step transfer molding was performed using an epoxy resin low-pressure molding material to produce a cup-shaped coreless armature.

When a thermal shock test was conducted on five of the iron-free armatures obtained above under the same conditions as in the example, two of them cracked and the dimensional change was 1/100 mm.
There was one that exceeded that number. Particularly, the lifting of the winding portion exposed on the armature surface was remarkable. Furthermore, the weight of the armature obtained in the example was approximately 20% lighter than that of the armature in the comparative example.

As explained above, in the method for manufacturing a iron core armature according to the present invention, the number of manufacturing steps is significantly reduced compared to the conventional method, and the iron core armature can be manufactured efficiently and labor-savingly. Children can be provided at low cost.

Furthermore, in the present invention, even if the armature winding part has an ultra-thin structure, damage to the insulating film of the wire and disconnection will not occur, and a coreless armature with excellent electrical performance can be manufactured. It does not cause deformation of the armature winding, in other words, it does not damage the electrical positional relationship between the winding and the commutator pieces, and when it is used as an ironless motor, its torque, rotation speed, brush life, etc. This makes it possible to stabilize the characteristics.

Furthermore, in the present invention, microcapsules containing a foaming agent are added to the resin composition applied to the armature, and the microcapsules are foamed during polymerization and curing of the epoxy resin to form microscopic hollow spheres. It can be significantly lighter than the previous model, and when used as an ironless motor,
In combination with the above-mentioned effects, the control responsiveness can be improved.

[Brief explanation of the drawing]

Figure 1 is a sectional view of a cup-type ironless motor using a coreless armature, Figure 2 is a perspective view of an armature winding group, and Figure 3 is a cup-shaped armature winding formed by shaping the winding group. FIG. 4 is a block diagram showing the manufacturing process of a conventional iron core armature, and FIG. 5 is a block diagram showing the manufacturing process according to the present invention. 1 is the armature winding group, 1' is the armature winding.

Claims (1)

[Claims] 1. Microcapsules containing a foaming agent that expands in volume at temperatures above the softening point to form microscopic hollow spheres, a synthetic resin with a photopolymerizable functional group, a photopolymerization initiator, and a curing agent are mixed into an epoxy resin. A liquid resin composition is prepared, and this resin composition is applied to an unshaped armature winding group formed by winding a predetermined number of electric wires, and the synthetic resin having a photopolymerizable functional group in the composition is applied. was photopolymerized by ultraviolet irradiation to temporarily fix the shape of the armature winding group, and then heated above a temperature at which the microcapsules expand in volume to form microscopic hollow spheres and the epoxy resin polymerizes and hardens. 1. A method for manufacturing a coreless armature, comprising integrally rigidifying at least an armature winding portion into a predetermined shape using a mold.