JPS624942B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method of manufacturing a wire-wound coreless armature. Fig. 1 is a cross-sectional view of a cup-shaped motor using a wire-wound type ironless armature, and Fig. 2 is a cross-sectional view of a cup-shaped motor using a wire-wound type ironless armature. FIG. 3 is a perspective view of a cup-shaped coreless coil obtained by shaping the temporarily fixed coil into a predetermined shape. In these figures, 1 is a temporarily fixed coil, 1' is a shaped ironless coil, 2 is a commutator, 3 is a shaft, 4 is a bearing, 5 is a brush, 6 is a magnet, 7 is a frame, and 8 is an ironless core. The coil 1', commutator 2, and shaft 3 are integrated into a rigid body with predetermined dimensions, and are made of a cured resin such as a molding material. A conventional manufacturing method for the ironless armature having the above configuration will be explained. FIG. 4 is a conventional process flow diagram. First, a predetermined number of self-bonding wires are wound at A, and then the self-bonding wires and each segment are fixed by solvent bonding or the like to form a temporarily fixed coil 1. At B, the temporarily fixed coil 1 is shaped into a predetermined cup shape or flat shape using a heating mold, and the fusion layer on the surface of the self-fused wire is melted and solidified, and the wires are bonded together to form the iron-free coil 1'. . At C, the lead wire of the coreless coil 1' is electrically connected to the commutator 2 via the commutator side coil terminal, and at D, the commutator 2 and the shaft 3 are bonded. By placing this in a resin molding mold at E and molding it with molding material, the shaft 3,
The commutator 2 and the coreless coil 1' are integrally made into a rigid body. As is clear from the above description, the conventional method for manufacturing a wire-wound coreless armature requires at least a plurality of steps of heating and pressurizing the coils 1, 1' in a mold. That is, step B in which the temporarily fixed coil 1 is shaped into a predetermined cup shape or flat shape to form the coreless coil 1', and step E in which the coreless coil 1' is embedded with molding material or the like are essential. In general, wire-wound coreless coils, for example in the case of armatures of cup motors or flat motors, have an ultra-thin structure due to their electrical design. When shaping into a coreless coil 1' having a die structure, frictional effects usually occur between the coils and between the coil molds.
As a result, damage to the wire coating or wire breakage occurs, particularly at coil terminals where the coil space factor is high due to the structure, resulting in process failures. Furthermore, in step E of embedding the coreless coil 1' with molding material, the coreless coil 1' is generally heated to 150 to 170° C. in a mold and then filled with the molding material under pressure. Even if a low-pressure molding material based on epoxy resin, polyester resin, etc. is used, the pressing force is approximately 20 to 50 kg/ ^cm2 , so the ironless coil 1' in the heated state cannot withstand this pressure. It was normal. As a result, the coil deforms, causing variations in the quality characteristics of the armature. On the other hand, since the coil has an ultra-thin structure, a portion of the coreless coil 1' to be embedded in the molding material is usually exposed on the armature surface even after molding. the 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 temperature changes, because the adhesive force between the coils is insufficient. Problems such as cracks appearing in the exposed coils occurred, which ultimately made it difficult to maintain the dimensional accuracy of the armature and caused electrical failures. In view of the above background, and as a result of intensive research, the present invention has been made based on the process defects, defects in armature characteristics, and defects in armature reliability that were inevitably caused by the conventional manufacturing method of ironless armatures. The present invention provides a method for manufacturing a coreless armature that not only solves the above problems but also brings surprising effects such as significant simplification of the manufacturing process. FIG. 5 is a process flow chart of the present invention. First, a predetermined number of self-welding wires are wound at A', and then the self-welding wires and each segment are fixed with solvent adhesive or the like to form a temporarily fixed coil 1. Next, the temporarily fixed coil 1 and commutator 2 are electrically connected at B'. Thereafter, at C', the temporarily fixed coil 1 and commutator 2 are placed in a coil shaping mold together with the shaft 3, and a coil friction buffer that is solid at room temperature is placed at the coil end of the temporarily fixed coil 1 on the commutator side. This is melted and liquefied and filled up to the end of the coil on the side opposite to the commutator, and at the same time, the temporarily fixed coil 1 is shaped into a predetermined shape. After the shaping is completed, by hardening the coil friction buffer that coexists with the ironless coil 1', commutator 2, and shaft 3 in the mold, the ironless coil 1', commutator 2, and shaft 3 are integrated into a rigid body. The iron core armature has been changed to Here, the coil friction buffer is a resin composition containing a lubricant as an essential component, which is solid at room temperature, and has a plasticizing temperature range and a curing temperature range, and can be formed into a predetermined amount and a shape that is easy to handle at a temperature below the plasticizing temperature. Use the processed one. The lubricant that is an essential component is the temporarily fixed coil 1.
During shaping, it is necessary to prevent adhesion between the mold surface and the outermost self-adhesive layer of the coil, to prevent friction between the coils and between the mold surface and the coil, to improve the fluidity of the coil friction buffer, and to prevent partial banding. Those effective for prevention etc. are appropriately selected from fatty acids, their metal salts, hydrocarbons, fatty acid amides, fatty acid esters, higher alcohols, etc., singly or in combination. The lubricants vary depending on the thermosetting resin composition that is the base of the coil friction buffer, but include stearyl alcohol, distearyl-4,5-epoxycyclohexane-1,2-dicarbonate, etc. with a melting point of 50 to 60°C, and stearic acid. , zinc stearate, calcium stearate, etc. are preferably mixed as appropriate. Further, as the thermosetting resin which is solid at room temperature and has a plasticizing temperature range, which is the base of the coil buffer, for example, epoxy resin, unsaturated polyester resin, diallyl phthalate resin, etc. can be used. It is sufficient to use a latent curing agent or catalyst that completely dissolves resin components having different molecular weights and has a melting point of 50 to 70°C, and has an activation temperature at least higher than the melting point of the resin. Furthermore, it is important that the base resin has a low melt viscosity at the shaping temperature of the temporarily fixed coil 1 and that it wets the coil well in order to fully exhibit the coil friction buffering effect of the lubricant. Further, the gelling time is preferably such that it has characteristics that do not interfere with the mold operation required for shaping the temporarily fixed coil 1 and is fast curing. Also, resins mixed with inorganic fillers are preferable due to curing shrinkage.
In some cases, favorable results may be obtained by imparting thixotropy. Examples of inorganic fillers include fibrous materials such as glass fiber and asbestos, silica,
There are grains of minerals and metal oxides such as talc, red iron oxide, and alumina, and these can be used alone or in combination to form a desired hardened product. In particular, the combined use of a fibrous filler increases the strength of the coil end portion of the iron-core coil 1' on the commutator side, which is advantageous for making the iron-core coil 1', the commutator 2, and the shaft 3 into an integral rigid body. . A resin composition consisting of a resin containing the above-mentioned lubricant as an essential component and a filler used as necessary is processed into a predetermined amount at a temperature below the activation temperature of the latent curing agent or catalyst contained therein. As a processing method, a well-kneaded resin composition is powdered and this powder is molded into tablets, or a predetermined amount is formed by extrusion molding or injection molding.
A coil friction buffer with a predetermined shape. It is desirable that the coil friction buffer be shaped into a disc or donut shape to make each drop easier to handle. Particularly preferred as a coil friction buffer is a bisphenol type epoxy resin and a polyester having the following structure.
Distearyl-4,5-epoxycyclohexane-1,2-dicarbonate as a lubricant is uniformly dissolved in a resin component using P-vinyl-phenol and an amine salt or an amine complex, and calcium stearate is further uniformly dispersed. It contains 40 to 50% by weight of silica as an inorganic filler.
Bisphenol type epoxy resin (epoxy equivalent
190, Ciel Chemical Epicote 828) and hydroxyl equivalent
120, poly-P-vinylphenol with a molecular weight of 3700 is blended with an epoxy group/hydroxyl group = 1.0, and BF ₃ -2-
1PHR of methylimidazole, distearyl-
4,5-epoxycyclohexane-1,2-dicarbonate 5PHR, calcium stearate
1PHR and 40% by weight silica has the general properties shown in the table below. This product does not change the epoxy group reaction rate, which reflects the degree of curing reaction, even if it is kept in the plasticization range of 60 to 70°C for 10 to 15 hours, so it can be easily injection molded in a specified amount without affecting storage stability. ,
It can be a coil friction buffer with a predetermined shape.

【table】

[Table] As described above, the main point of the method for manufacturing a coreless armature of the present invention is that the conventional step of molding the coreless coil 1' with a molding material is eliminated. It is an object of the present invention to provide a coil friction buffer that has the role of this molding material and the role of buffering the frictional effect during shaping of the temporarily fixed coil 1, and also takes into account mass productivity, ease of handling, etc. The effect produced by this is that it is possible to prevent the occurrence of problems related to process defects, quality characteristics of the armature, and reliability of the armature, which are unavoidable in conventional manufacturing methods. In addition, since large hydraulic machines such as molding machines for molding materials are not required, process equipment is simplified, and there is no material loss as the coil friction buffer is pre-prepared to a predetermined amount required to make the armature rigid. This can be said to be the ideal manufacturing method for iron-free armatures that saves resources and energy. Next, the embodiment of the present invention and the conventional method will be compared under the same conditions. Example A self-bonding polyurethane insulated wire having a butyral resin fusion layer with a wire diameter of 0.15φ was wound in a laminated manner on a winding frame with 49 turns and 7 segments and an outer diameter of 19.6φ.
After adhering with acetone, it was taken out from the winding frame to obtain a temporarily fixed coil 1 (Step A'). Next, after soldering the lead wires of the temporarily fixed coil 1 and the commutator 2 (step B'), they are placed together with the shaft 3 in a coil shaping mold preheated to 150°C, and the outer diameter is 17± as shown in the table above. A coil friction buffer with a diameter of 0.5 mm, an inner diameter of 6±0.5 mm, and a height of 3 mm is placed on the coil end of the temporarily fixed coil 1 on the commutator side. The coil shaping mold was clamped at a speed of about 2 cm/sec and held for 3 minutes. By opening the mold, the inner diameter is 19.5φ, the outer diameter is 20.8φ, and the height is 30.0mm.
A cup type ironless armature was obtained. According to this example, no electrical failure occurred even when 50 temporarily fixed coils were tested under the same conditions. In addition, after heating the five iron core armatures mentioned above to 120℃,
Even when the armature was immediately subjected to thermal shock five times by being immersed in a dry ice-MeOH solution heated to -40°C, the deflection of each part of the armature remained unchanged and no cracks were generated. Comparative Example A self-bonding polyurethane insulated wire having a wire diameter of 0.15φ and a butyral resin bonding layer as in the example was wound, and then temporarily bonded coil 1 was bonded with acetone.
(Step A). This temporarily fixed coil 1 is placed in a coil shaping mold heated to 150°C, and the mold is clamped at a speed of 2 cm/sec, and the adhesive layer on the surface of the self-fused wire is melted and solidified to bond the wires together. Iron core 1' is made (Step B). In this B process, 4 out of 50 units had disconnection defects mainly at the coil end of the coreless coil 1'. Next, the lead wire of the coreless coil 1' is soldered to the commutator 2 via the coil terminal on the commutator side (step C), the commutator 2 and the shaft 3 are bonded together (step D), and the low-pressure diallyl phthalate resin is By transfer molding with a molding material, the shaft 3, commutator 2, and coreless coil 1' are made into an integral rigid body (step E). When five of the above iron core armatures were subjected to a thermal shock test under the same conditions as in the example, cracks occurred in all of them.
The deflection in various parts of the armature reached a maximum of 0.30mm, and on average was 0.22mm. Particularly, the lifting of the coil portion exposed on the armature surface was noticeable. As is clear from the above description, according to the present invention, the coil can be shaped and made rigid while the entire coil is wetted by the coil friction buffer.
The process is simplified compared to the conventional method in which the shaping process of the temporarily fixed coil and the molding process with the molding material are performed in separate processes, and the molding material is not pressurized and filled into the mold as in the conventional method. Also, the coil is less likely to be deformed, and the coil is prevented from being exposed on the armature surface after the coil friction buffer has hardened. As a result, even when the armature is in use, the problem of cracks occurring from exposed coil portions due to centrifugal force, vibration, etc. caused by high-speed rotation can be significantly reduced. Furthermore, since the entire coil is shaped while being wetted, it is possible to buffer the friction during coil shaping, prevent damage to the wires, and improve the quality and reliability of the armature.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a cup-shaped motor using a wire-wound ironless armature, and Figure 2 is an unshaped temporarily fixed coil that has been wrapped with a predetermined number of self-welding wires and then fixed with solvent adhesive etc. 3 is a perspective view of a coreless coil in which a temporarily fixed coil is shaped into a predetermined shape and the fused layer on the surface of the wire is melted and solidified. FIG. 4 is a diagram showing the progress of the manufacturing process of a conventional ironless armature. , FIG. 5 is a diagram showing the progress of the manufacturing process of the iron core armature of the present invention. 1... temporarily fixed coil, 1'... shaped coreless coil, 2... commutator, 3... shaft.

Claims (1)

[Claims] 1. A step of electrically connecting an unshaped temporary fixed coil made by winding a predetermined number of self-fused electric wires with a commutator and installing it together with a shaft in a heated coil shaping mold, melting point A step of installing a coil friction buffer in the mold, which is made by processing a thermosetting resin composition that is solid at room temperature and has a plasticization temperature range and has a lubricant of 50 to 60°C as an essential component into the mold, and during mold clamping. heating and melting the coil friction buffer to wet the entire unshaped temporarily fixed coil while shaping the temporarily fixed coil into a predetermined shape;
A method for producing a coreless armature, which comprises the steps of: a coil shaped into a predetermined shape is made rigid into a predetermined size by heat curing of a coil friction buffer, and is then integrated with a shaft and a commutator. 2. The method for manufacturing a coreless armature according to claim 1, wherein the coil friction buffer contains a bisphenol type epoxy resin, poly-P-vinylphenol, an amine salt or an amine complex, and a lubricant.