JP4870931B2 - Environmental resistant axial fan - Google Patents

Description

  The present invention is an environmentally resistant axial flow fan, in particular, a highly environmentally resistant axial flow that does not impair the cooling function even if a water-soluble cutting agent that is normally used as a cutting agent for machine tools falls on or is sucked in. It is about fans.

  Conventionally, an axial fan is used for cooling a control device installed in the vicinity of a machine tool. FIG. 6 is an exploded schematic sectional view showing a state before assembling a conventional axial fan. In FIG. 6, an axial fan 100 includes a coil 1 that is an electrical part, and the coil 1 is wound by attaching an insulating material 3 to a laminated core 2. The coil 1 is integrated with a circuit board 6 on which an electronic component 4 and a capacitor 5 (hereinafter simply referred to as mounting components 4 and 5) are mounted, and is mounted on a case 7 to which a lead wire 14 is attached. A yoke 9 that forms a magnetic path and a magnet 10 are fitted inside the rotating blade 8 inside. A rotating shaft 11 attached to the center of the blade 8 is attached to the case 7, inserted into the bearing 12, and integrated with a retaining metal fitting 13.

  The coil 1 is generally made of polyurethane enamel copper wire or polyester enamel copper wire. Under normal operating conditions, special insulation treatment is not performed, but in the case of an axial fan used around machine tools, the spraying agent splashes on or sucks, and the insulation is impaired. After applying an insulating coating to the circuit board 6 including the coil 1 and the mounting components 4 and 5, the circuit board 6 was assembled in the case 7.

  Cutting agents generally used in machine tools are strongly alkaline and conductive, and contain a surfactant, so that they penetrate into the inside of the synthetic resin material and have a dissolving power. The mist falls on or is sucked into the axial fan 100 and adheres to coils and electronic circuit boards, which are electrical parts of the axial fan 100, thereby damaging the insulation and losing the function as the axial fan 100. There is.

  Cutting agents are broadly classified into water-insoluble and water-soluble. Recently, cutting agents used in machine tools are mainly water-soluble, and the content composition is high due to demands for high-speed machining and high-precision machining. It is becoming more complex and very harsh from the point of view of electrical insulation. In other words, mineral oil and synthetic oil contain a large amount of surfactants in addition to lubricants to reduce wear of processing tools, improve cooling performance and improve sharpness, and contain rust preventives, antiseptics, and antifoaming agents. ing. As a result, they exhibit strong alkalinity (pH: 9 to 10) and are usually diluted with water, but have conductivity (about 0.5 to 1.5 m Siemens / cm).

  Accordingly, the electrical components of the axial fan placed in an environment where they fall down cannot be protected by the conventional insulating coating, and an insulation failure such as a short circuit of the electronic circuit or a short of the coil layer occurs. Air cooling, which is the original function, has been difficult.

  Since the cutting agent has conductivity as described above, if a portion having a potential difference is not coated with an insulating coating, a leakage current flows immediately, leading to a failure. Further, the surfactant may permeate into the enamel insulation film or insulation coating of the coil or the material constituting the axial fan 100 and swell or dissolve. In other words, it has been difficult to produce a durable axial fan in this adverse environment unless the materials are carefully examined and selected to cause internal deterioration of the materials.

  Conventionally, the stator after winding and molding is heated for dehumidification, and when the temperature is still sufficiently high, it is immersed in an epoxy resin liquid, the temperature of the epoxy resin in the vicinity of the stator is increased, and the fluidity is increased. In order to facilitate the penetration of the epoxy resin around the winding itself, between the core and the winding, and the space between the windings, the pinholes of the winding are closed and heat-cured. Thereafter, it is put into a mold and further molded by injecting an epoxy resin (for example, see Patent Document 1).

  Also, a fanless motor that molds a stator, a circuit board including electronic components, and a plurality of lead wires with an epoxy resin having a hardness after curing of Shore D30 to Shore D90 in a state of being housed in the stator side case. Is known (see, for example, Patent Document 2).

JP 2003-333787 A JP 2001-128408 A

  However, the axial fan of Patent Document 1 has a problem that only the stator is molded with epoxy resin, and the circuit board is not taken into consideration. Further, in Patent Document 2, since the stator, the circuit board, and the like are molded in a state of being accommodated in the case, there is a problem that disassembly is difficult in recycling after the end of the life.

  The present invention has been made in view of the above, and even if a water-soluble cutting agent normally used as a cutting agent for machine tools falls or sucks, it does not cause an insulation failure and impairs the air cooling function. The objective is to provide an environmentally resistant axial fan that has high environmental resistance and excellent recyclability.

In order to solve the above-described problems and achieve the object, an environmentally resistant axial fan according to claim 1 of the present invention is fixed to a coil wound around an insulating material mounted on a laminated core and the insulating material. And a core portion having a circuit board on which electronic components are mounted, a blade portion having a rotating shaft and a blade mounted with a magnet, and a case mounted with the core portion and rotatably holding the blade portion. An axial fan, the circuit board including the coil of the core part and the electronic component is molded with an epoxy resin cured with an aromatic amine curing agent, and cured with the aromatic amine curing agent. epoxy resin is cured at a temperature of 70 ° C. to 90 ° C., epoxy resin after blended with the aromatic amine curing agent, the viscosity of 800CPS~1500CPS a temperature range of 50 ° C. to 60 ° C. Characterized in that to hold the circumference of at least 30 minutes.

In the environmentally resistant axial fan according to claim 2 of the present invention, the magnet material is nylon or high nitrile as the binder of the plastic molded magnetic material.

In the environmentally resistant axial fan according to claim 3 of the present invention, at least the blades and the case of the environmentally resistant axial fan are polybutylene terephthalate not mixed with polyethylene terephthalate, acrylonitrile butadiene styrene, and It is produced from these plastic alloys.

Environmental resistance axial flow fan according to the present invention, since the circuit board including a coil and electronic components of the core portion is molded with epoxy resin that is cured with an aromatic amine curing agent, usually as a cutting agent for a machine tool Even if the water-soluble cutting agent used falls or is sucked in, there is an effect that the air cooling function is not impaired. In addition, since the magnet and other plastic members are made of members having excellent characteristics with respect to the cutting agent, an effect of producing an axial fan having further improved durability and reliability can be obtained. Furthermore, that since it is attached to the case after the molding of the circuit board including a coil and electronic components of the core with an epoxy resin cured with an aromatic amine curing agent is excellent in recycling property after completion life of the axial fan There is also an effect.

Hereinafter, an embodiment of an environmentally resistant axial fan according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiment.
FIG. 1 is a schematic cross-sectional view showing an environmentally resistant axial fan (hereinafter simply referred to as an axial fan) according to an embodiment of the present invention. In FIG. 1, the blade portion and the core portion are also shown. In FIG. 1, an axial fan 100 </ b> A includes a coil 1, which is an electrical component, and the coil 1 is wound around an insulating material 3 with an insulating material 3 attached to a core, for example, a laminated core 2. The coil 1 and the circuit board 6 on which the electronic component 4 and the capacitor 5 (hereinafter simply referred to as mounting components 4 and 5) are mounted are integrated to form a core portion 20. Here, the circuit board 6 including the coil 1 and the mounting part 4 and 5, as described later, as a mold material are molded with epoxy resin that is cured with an aromatic amine curing agent.

  A yoke 9 forming a magnetic path is fitted inside the rotating blade 8, a magnet 10 is fitted inside the yoke 9, and a rotating shaft 11 is attached to the center. These blades 8, yoke 9, magnet 10 and rotating shaft 11 constitute a blade portion 30. The core part 20 described above is mounted and fixed to the case 7. Further, the rotating shaft 11 of the blade portion 30 is inserted into the bearing 12 of the case 7, and the retaining metal fitting 13 is inserted at the tip of the rotating shaft 11. Thereby, the core part 20 and the blade | wing part 30 are integrated with the case 7. FIG. Thereafter, the lead wire 14 is attached to the case 7.

In axial flow fan 100A configured as described above, the circuit board 6 including the coil 1 and the mounting part 4 and 5 of the core portion 20, as a mold material, an epoxy resin cured with an aromatic amine curing agent Molded. Various epoxy resins can be used as the epoxy resin. The curing agent, preferably an aromatic amine curing agent may be used.

The aromatic amine curing agent, m-phenylenediamine and diaminodiphenylmethane is typically available. A modified product containing 100% or at least 90% of these is used. As a commercial product, Nippon Synthetic Chemical Co., Ltd.'s curing agent: model number SH-37 corresponds to this, and exhibits desirable curing when blended with the main material: SR-37. The curing agent is used alone, and is not used for a catalyst such as an acid anhydride curing agent.

Next, a description will be given curing conditions when using the aromatic amine curing agent and epoxy resin as the mold material.
Figure 2 is a graph showing the time course of viscosity of the epoxy resin at each temperature after blending an aromatic amine curing agent. In FIG. 2, the epoxy resin was held at 40 ° C., 50 ° C. and 60 ° C., respectively, after blending the curing agent, and the viscosity of each epoxy resin was measured every 10 minutes. When the temperature of the epoxy resin is 40 ° C., the viscosity exceeds 2500 CPS immediately after the curing agent is blended, which is not desirable. When the temperature of the epoxy resin is 50 ° C. to 60 ° C. and within 30 minutes from the addition of the curing agent, the viscosity of the epoxy resin is in the range of 800 CPS to 1500 CPS, and can be suitably used as a molding material.

FIG. 3 is a diagram showing a temporal change in heat generation during curing of the epoxy resin. 3, as a curing agent, and an aromatic amine curing agent, shows a case of using an amine curing agent for comparison. When an amine curing agent is used, the reaction heat generation is high and the curing is quick. Further, the curing heat generation may reach a peak of 110 ° C. or higher. This also leads to the fact that the low viscosity region cannot be obtained for a long time.

In contrast, when using the aromatic amine curing agent, upon curing the epoxy resin at 80 ° C., by suppressing heat generation as much as possible it can be reduced to 90 ° C. or less. In addition, although heat_generation | fever depends also on the temperature which hardens an epoxy resin, 70 to 80 degreeC is suitable. If the temperature is lower than this, the curing time is very long and the workability deteriorates, so that it cannot be employed. The capacitor 5 which is one of the mounted parts is vulnerable to heat. When the liquid epoxy resin is cured, there is an exothermic reaction, and if the temperature rises abnormally, the capacitor 5 may be damaged. When using the aromatic amine curing agent as a curing agent, as is clear from FIG. 3, since the heat generation during curing can be suppressed to 90 ° C. or less, failure in the electronic component 5 such as a weak capacitor into heat Can be avoided.

  Therefore, the epoxy resin as the molding material is selected so that the viscosity of the epoxy resin after blending the curing agent is in the range of 50 ° C to 60 ° C and the viscosity can be kept in the range of 800 CPS (centipoise) to 1500 CPS for at least 30 minutes. It is desirable to do. An epoxy resin and a curing agent satisfying such conditions are selected, and a heating program capable of performing molding at a heating temperature in the range of 50 ° C. to 60 ° C. and a heating time of 30 minutes or less is assembled, and the mold of the core portion 20 I do. The epoxy resin is preferably cured at a temperature of 90 ° C. or lower.

  By adopting the molding material and curing conditions as described above, the time in the low viscosity region is long, and the poxy resin in the mold is placed in the gap between the wires of the coil 1 and the core where the laminated core 2 is laminated. Easy to penetrate. Therefore, a method such as vacuum impregnation is not necessary. Filling these gaps prevents the penetration of the cutting agent and contributes to increasing the durability of the axial fan 100A. Furthermore, it is not necessary to apply a synthetic resin varnish or the like in the gap between the laminated cores 2 in advance, and the workability is good.

  When the core part 20 is molded, the circuit board 6 including the coil 1 and the mounting components 4 and 5 is placed in a mold and molded with an epoxy resin after blending a curing agent. That is, in order to prevent the coil 1 and the circuit board 6 from being melted by the cutting agent and short-circuiting the circuit, the coil 1 and the epoxy resin of the present invention that is strong against the cutting agent are covered. As a result, the entire circuit board 6 including the coil 1 and the mounting components 4 and 5 is molded with an epoxy resin, so that the axial flow fan 100 </ b> A is durable even in a bad environment with a cutting agent or other conductive splashes. Can be improved.

  Thereafter, the core part 20 in which the epoxy resin is molded is attached to the case 7. In addition, after mounting the core part 20 in the case 7, the method of molding with an epoxy resin is also considered. However, in addition to deviating from the current assembly line configuration and becoming a special line, it is not a good idea, and when the axial fan 100A reaches the end of its life and it is desired to recycle, it is difficult to remove the core portion 20 from the case 7 and difficult to disassemble. This method is undesirable because of its drawbacks. On the other hand, if the core part 20 molded with epoxy resin is attached to the case 7, the attached core part 20 can be easily removed, and the recyclability is improved.

  Even if only electric parts are made strong against the cutting agent, the function as the axial fan 100A cannot be exhibited if there are other weak points. Therefore, in the present invention, nylon or high nitrile rubber is adopted as the binder of the plastic molding magnetic material in the material of the magnet 11. By using nylon or high nitrile rubber as a binder, an axial fan 100A that can be used stably without penetration of the cutting agent is obtained.

  Furthermore, it is desirable to use polybutylene terephthalate (PBT), acrylonitrile butadiene styrene (ABS), and these plastic alloys, which are not mixed with polyethylene terephthalate, as plastic materials used for structural materials such as the case 7 and the blades 8. For the case 7 and the blade 8 using these materials, a test was performed to see the durability balance against the cutting agent. The entire axial flow fan 100A was immersed in a cutting agent at 85 ° C. to evaluate the durability, but it was found that the balance was good and the durability was excellent.

Hereinafter, based on an Example and a comparative example, this invention is demonstrated further more concretely.
(Examples 1-2, Comparative Examples 1-6)
Cutting agents that are particularly problematic as chemicals used in machine tools are water-soluble cutting agents, and there are two types, an emulsion type in which mineral oil components are mainly emulsified and a soluble type in which water is dissolved in water. All of them contain a surfactant, have a function of lowering the surface tension, and improve wettability. In other words, it has the property of easily penetrating even into extremely fine gaps and thus easily penetrating into the inside of the synthetic resin. Therefore, as the synthetic resin used for the mold, it is necessary to select a material that does not deteriorate due to the penetration of these cutting agents, or a material that has little deterioration or a slow progress. Therefore, representative types of emulsion type and soluble type of water-soluble cutting agent were selected, and the materials were subjected to a selection test by immersing them.

The mold materials 15 that were comparatively verified were four types: epoxy resin (aromatic amine-based curing agent), epoxy resin (using amine-based curing agent), silicone rubber, and hot-melt polyester. These materials were respectively immersed in cutting agent A (solvable type) and cutting agent B (emulsion type) at 85 ° C., and the change with time in hardness after immersion was measured. In Table 1, the case of using the aromatic amine curing agent as Example showed other as a comparative example. Each material was immersed in the two types of cutting agents A and B, heated at 85 ° C., taken out at an arbitrary time, and the hardness was measured. The hardness meter was JIS-K6301 A-TYPE. The fact that the hardness decreases means that the cutting agent has permeated and the swelling or dissolution has progressed. The results are shown in Table 1. FIG. 4 shows the results of Table 1.

  In the molding material shown in Table 1 and FIG. 4, an epoxy resin (aromatic amine curing agent, Examples 1 and 2) was a good result. Epoxy resins (amine-based curing agents, Comparative Examples 1 and 4) are not perfect because of their reduced hardness. Further, the hot-melt polyester (Comparative Examples 3 and 6) was significantly swollen to the same extent as the silicon rubber (Comparative Examples 2 and 5).

(Examples 3-6, Comparative Examples 7-10)
The magnet 11 was molded from a ferrite magnetic powder using a synthetic resin or plastic material as a binder, and was tested by changing the type of the binder. The test materials were four types of high nitrile rubber (Examples 3 and 5), nylon (Examples 4 and 6), nitrile rubber (Comparative Examples 7 and 9) and chlorinated polyethylene (Comparative Examples 8 and 10). . These materials were immersed in the two types of cutting agents A and B, heated at 85 ° C., taken out at an arbitrary time, and the hardness was measured. The hardness meter was JIS-K6301 A-TYPE. The fact that the hardness decreases means that the cutting agent has permeated and the swelling or dissolution has progressed. The results are shown in Table 2. FIG. 5 shows the results of Table 2.

  In the binder of the magnet material shown in Table 2 and FIG. 5, it was found that high nitrile rubber and nylon were stable. That is, it has been found that the axial fan 100A with high reliability can be manufactured without penetration of the cutting agent and progression of swelling or dissolution.

  As described above, the axial flow fan according to the present invention is a durable axial flow that does not impair the air cooling function even if a water-soluble cutting agent that is normally used as a cutting agent for machine tools falls or is sucked in. Useful for fans. In particular, it is suitable for use under severe use conditions or when recyclability is required.

It is a schematic sectional drawing which shows the axial fan concerning one embodiment of this invention. It is a graph showing the time course of viscosity of the epoxy resin at each temperature after blending an aromatic amine curing agent. It is a diagram which shows the time-dependent change of the heat_generation | fever at the time of epoxy resin hardening. It is a diagram which shows the hardness change after immersing the molding material in Examples 1-2 and Comparative Examples 1-6 in a cutting agent. It is a diagram which shows the hardness change after immersing the binder of the material for magnets in Examples 3-6 and Comparative Examples 7-10 in a cutting agent. It is a schematic sectional drawing which decomposes | disassembles and shows the conventional axial fan.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coil 2 Laminated core 3 Insulation material 4 Electronic component 5 Capacitor 6 Circuit board 7 Case 8 Blade 9 York 10 Magnet 11 Rotating shaft 12 Bearing 13 Retaining metal fitting 14 Lead wire 15, 16 Mold material 20 Core part 30 Blade part 100A shaft Current fan

Claims (3)

A coil wound around an insulating material mounted on a laminated core, a core portion having a circuit board fixed to the insulating material and mounted with electronic components, a blade portion having a rotating shaft and a blade mounted with a magnet, and the core An environmentally resistant axial flow fan equipped with a case and a case for rotatably holding the blade portion,
Circuit board including a coil and electronic components of the core portion is molded with epoxy resin that is cured with an aromatic amine curing agent,
The epoxy resin cured with the aromatic amine curing agent is cured at a temperature of 70 ° C. to 90 ° C. ,
The epoxy resin after blending the aromatic amine-based curing agent can maintain a viscosity of 800 CPS to 1500 CPS for at least 30 minutes in a temperature range of 50 ° C. to 60 ° C. . 2. The environmentally resistant axial fan according to claim 1 , wherein the magnet material is nylon or high nitrile as a binder of a plastic molded magnetic material. At least the blade and the case of the environmental resistance axial flow fan, polybutylene terephthalate which is not mixed with polyethylene terephthalate, to claim 1 or claim 2, characterized in that it is made from acrylonitrile butadiene styrene and these plastic alloy The environmentally resistant axial fan described.

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