JP2006035831A - Method for manufacturing rotor for motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize the injection molding of a filler while each constituent member of a rotor is heated up to a predetermined temperature level in a high-temperature state, through a safe and simple operation and thereby, ensure the stabilized availability of successful molding precision by improving the fluidity and curability of the injected filler. <P>SOLUTION: In this method for manufacturing a motor rotor, a molten resin 50 is injected into a cavity formed by mold clamping in such a state that the constituent members of a motor rotor 10 is built/set in a cavity-side half 41 of an injection molding machine 40, and thus the motor rotor 10 can be formed in a monolithic form by filling a building-in gap between the constituent members. Prior to injecting the resin 50, the constituent members built/set inside the cavity side half 41 of the injection molding machine 40 are heated up to a temperature level which can keep the molten resin 50 fluidized by an electromagnetic induction heating device arranged in the injection molding machine 40. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a rotor for a motor. More specifically, the present invention relates to a method for manufacturing a motor rotor for easily and precisely manufacturing a motor rotor.

Usually, a rotor used in a motor has, for example, a central position of a rotor core formed in a cylindrical shape by laminating a plurality of disk-shaped electromagnetic steel plates (those formed by stamping). Each slot shape (communication shape in which each through-hole formed in each layer of the electromagnetic steel sheet is aligned in the stacking direction) formed in a position along the peripheral edge, such as a shaft or a permanent magnet (magnet that becomes the field source of the rotor), etc. The assembly member is assembled and configured. In addition, an end plate is disposed on the laminated end surface of the electromagnetic steel sheets, and is integrally formed by caulking and fixing to the shaft.
In addition, each component of the rotor described above is assembled and set in a mold of an injection molding machine, and a polyester resin having a bonding function, for example, in a gap between the components formed by the assembly. When the thermosetting resin such as is filled by injection molding, each component is fixed and formed integrally. Therefore, for example, even when an assembly member such as a shaft or a permanent magnet is assembled with a gap with respect to each slot shape of the rotor core, the gap is filled with resin, so that there is no backlash. Assembly state.
Here, conventionally, in order to improve the fluidity and curability of the resin injected at the time of the injection molding, prior to injection molding, each component of the rotor is preliminarily attached to a heating device such as a high-temperature furnace. A process of charging and heating to a predetermined temperature has been performed. Then, each component in a high temperature state heated and heated is set in a mold of an injection molding machine to perform injection molding.
This type of related technology is disclosed, for example, in Patent Document 1 below.

JP 2001-121252 A

However, in the above-described conventional technique, additional equipment such as a high-temperature furnace is required to heat and raise the temperature of each component member of the rotor as the insert member. Therefore, it is necessary to secure an extra installation space. Moreover, since each component member of the rotor heated and heated in the high temperature furnace is in a high temperature state, the components are taken out from the high temperature furnace and assembled and set in the mold of the injection molding machine. This is not preferable in terms of assembly workability and work safety. Moreover, it has become a factor of cost increase accompanying the increase in work man-hours.
Further, each component of the rotor taken out from the high-temperature furnace and set in the mold of the injection molding machine has been subjected to the injection of the filler (resin) in spite of being subjected to the above-described heating temperature raising process. As the waiting time elapses, the temperature may decrease. In addition, since the rate of temperature change varies from process to process, it is difficult to control the fluidity and curability of the filler uniformly. Therefore, a good and constant molding accuracy could not be obtained.

  The present invention has been devised to solve the above-mentioned problems, and the problem to be solved by the present invention is to heat and raise each component of the rotor to a predetermined temperature by a safe and simple operation. This is to enable the injection molding of the filler in a heated high temperature state, thereby improving the fluidity and curability of the injected filler so that good molding accuracy can be stably obtained. Is to do.

In order to solve the above problems, the method for manufacturing a rotor for a motor of the present invention takes the following means.
First, according to the first aspect of the present invention, a molten filler is injected into a cavity formed by clamping a mold in a state where components of a rotor for a motor are assembled and set in a mold of an injection molding machine. This is a manufacturing method for integrally forming a motor rotor by filling assembly gaps between components, and is assembled and set in a mold of an injection molding machine prior to injecting the filler. The component in the state is heated to a predetermined temperature at which the fluidity of the filler in the molten state can be maintained by the heating means provided in the injection molding machine.
According to the first aspect of the present invention, the component of the rotor for the motor is a predetermined assembly capable of maintaining the fluidity of the molten filler by the heating means while being assembled and set in the mold of the injection molding machine. The temperature is raised to a temperature. Therefore, these components are put in a separate heating device such as a high-temperature furnace in advance and heated to raise the temperature, and then the components that have reached a high temperature are taken out of the furnace and assembled in the mold of the injection molding machine. The processing work that has been conventionally performed, such as, is omitted. Furthermore, according to this heating means, it is possible to heat-treat the constituent members assembled and set in the mold until just before the stage of injecting the molten filler. Therefore, the molten filler is injected into the cavity while the constituent member is heated to a predetermined temperature. Thereby, the filler in a molten state is filled in the assembly gap between the constituent members with good fluidity. In the case where the filler is made of a thermosetting resin, it is preferable that the temperature is raised to a temperature at which curing after filling is performed satisfactorily.

Next, a second invention of the present invention is the electromagnetic induction heating apparatus in which the heating means is disposed in the mold of the injection molding machine in the first invention described above, and the assembly set in the mold. The component in the state is heated to a predetermined temperature at which the fluidity of the molten filler can be maintained by electromagnetic induction heating.
Here, the electromagnetic induction heating device has a well-known configuration for generating a high-frequency magnetic field around the heating coil by supplying a high-frequency current to the spiral heating coil for generating magnetic force. An eddy current (inductive current) flows in the constituent member due to the generated magnetic field. At this time, the component members are heated by Joule heat generated as resistance heat.
According to the second aspect of the invention, the electromagnetic induction heating device in which the heating coil is arranged in the mold of the injection molding machine allows the motor rotor component member to maintain the fluidity of the molten filler. The temperature is raised to the temperature. Specifically, Joule heat is directly generated in the component member set in the mold by electromagnetic induction heating. As a result, the component is quickly heated up to the predetermined temperature. Further, the target temperature control can be performed with high accuracy by changing the frequency of the supply current. That is, it is possible to raise the temperature of the constituent member to the predetermined temperature in a short time and with high accuracy.

The present invention can obtain the following effects by taking the above-described means.
First, according to 1st invention of this invention, the structural member of the rotor for motors which is an insert member can be heat-processed within the type | mold of an injection molding machine. That is, as in the prior art, the process of heating and raising the components to a predetermined temperature at which the fluidity of the molten filler can be maintained in advance by separate equipment such as a high-temperature furnace becomes unnecessary. Therefore, space saving of the entire equipment can be achieved. Furthermore, the operation | work which puts in and takes out a structural member to a high temperature furnace can be skipped. Furthermore, since it is no longer necessary to handle a high-temperature component that has been heated and heated, assembly workability and work safety can be improved. Furthermore, the component can be heat-treated in the mold of the injection molding machine until just before the stage of injecting the molten filler. Accordingly, the injection molding of the filler can be performed in a high temperature state in which the constituent members are heated to a predetermined temperature capable of maintaining the fluidity of the filler in the molten state, and a highly accurate molded product can be stably produced. can get.
Furthermore, according to the second aspect of the present invention, the component of the motor rotor can be efficiently heated and heated by electromagnetic induction heating. Further, the temperature control of the constituent members can be performed with higher accuracy, and the control can be easily performed at a predetermined temperature capable of maintaining the fluidity of the molten filler.

  Embodiments of the best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is a process diagram showing a processing state in which the components of the motor rotor 10 are heated and heated in the mold of the injection molding machine 40.

  The motor rotor 10 obtained by the manufacturing method of the present embodiment is configured as follows. That is, as well shown in FIG. 1, a shaft 30, permanent magnets 31, and end plates 32, 33 are provided to a rotor core 20 configured by stacking a plurality of disk-shaped electromagnetic steel plates 21 into a columnar shape. Each is assembled and configured. The assembly gap formed between the rotor core 20 and each assembly member is filled with resin 50. The resin 50 used in the present embodiment is a thermosetting polyester resin that is excellent in oil resistance, heat resistance, and the like and functions as a fixing member that does not deteriorate even in the use environment of the motor. Here, the resin 50 corresponds to the filler of the present invention. Thereby, the rotor core 20 and each said assembly member are obtained integrally. Hereinafter, the detail about each structure of the rotor 10 for motors is demonstrated.

First, as shown in FIG. 1, the rotor core 20 is formed in a cylindrical shape by laminating a plurality of electromagnetic steel plates 21 punched and formed into a disk shape by press working. Further, through holes are formed at positions along the axial center and the periphery of each layer of the electromagnetic steel sheets 21. Therefore, by laminating a plurality of electromagnetic steel plates 21 into a cylindrical shape, these through holes are formed aligned in the laminating direction. As a result, a shaft slot 23 that can be disposed through the shaft 30, a magnet slot 24 that can be embedded with a permanent magnet 31 that serves as a motor field source, and a filling slot 25 that can be filled with a resin 50 are formed. Is done.
Here, the size and shape of the shaft slot 23 and the magnet slot 24 described above are used in order to improve the assembling workability of the shaft 30 and the permanent magnet 31 that are arranged at the time of lamination and penetrated. The shaft 30 and the permanent magnet 31 are set to be slightly larger than the size (not shown).

Next, as shown in FIG. 1, the shaft 30 is disposed so as to penetrate the shaft slot 23 formed in the axis of the rotor core 20 described above. Thereby, the radial positioning of each layer of the electromagnetic steel sheet 21 which comprises the rotor core 20, and the circumferential direction can be performed in advance. As described above, a fixed gap is formed between the shaft 30 and the shaft slot 23. Therefore, finally, the resin 30 is filled in the assembly gap by injection molding, so that the shaft 30 and the rotor core 20 are integrally fixed in position.
Next, the permanent magnet 31 functions as a field source of the motor rotor 10 in use, and a plurality of magnet slots formed along the peripheral portion of the rotor core 20 as well shown in FIG. 24 is embedded and arranged. Further, the permanent magnet 31 is set so that a certain gap is formed in the fitting with the magnet slot 24. Therefore, finally, the resin 50 is filled in the assembly gap by injection molding, whereby the permanent magnet 31 and the rotor core 20 are integrally fixed in position.
Next, the end plates 32 and 33 are respectively disposed on the laminated end surfaces 22 of the electromagnetic steel plates 21 constituting the rotor core 20 as well shown in FIG. Specifically, the right end plate 32 shown in FIG. 1 is made of a steel plate, and can be integrated with the shaft 30 by being inserted into the shaft 30 and fixed by caulking. Further, the left end plate 33 shown in FIG. 1 is formed by injection molding, and is formed by being integrally molded with the resin 50 filled in other gaps. The both end plates 32 and 33 prevent the rotor core 20 and the shaft 30 from jumping out.

  Next, the configuration of the injection molding machine 40 will be described. As shown in FIG. 1, the injection molding machine 40 that performs the injection molding of the resin 50 as the fixing member described above is a component of the motor rotor 10 that is assembled and set (the rotor core 20, the shaft 30, the permanent magnet 31, And a fixed mold 41 (the right mold shown in FIG. 1) and a movable mold 42 (the left mold shown in FIG. 1) arranged to be openable and closable in the axial direction of the end plate 32). ing. The fixed mold 41 and the movable mold 42 are heated by using a well-known electric heater or a mold temperature controller. That is, in the former, an electric heater is built in the fixed mold 41 or the movable mold 42, and heating is performed by energizing the heater. In the latter case, the temperature is adjusted or maintained by heating water or oil as a heating medium and circulating it around the fixed mold 41 or the movable mold 42 using a pump.

As well shown in FIG. 1, the injection molding machine 40 is provided with an electromagnetic induction heating device 43 for heating the components assembled and set in the mold. The electromagnetic induction heating device 43 includes a heating coil 44 disposed in the fixed mold 41 and the movable mold 42, and a frequency conversion control unit (not shown) for supplying a high-frequency current to the heating coil 44. It is configured. Therefore, when a high frequency current is supplied from the frequency conversion control unit, a high frequency magnetic field is generated around the heating coil 44. An eddy current (inductive current) flows in the components assembled and set in the mold by the action of the magnetic field. Thereby, Joule heat as resistance heat is generated in the component member itself, and the component member is efficiently heated and heated. Here, the set temperature at which the component members are heated and heated can be easily controlled by appropriately adjusting the frequency of the current supplied from the frequency conversion control unit. Therefore, the component is efficiently and accurately heated up to a temperature (for example, 150 ° C.) at which the fluidity and curability of the molten resin 50 (thermosetting polyester resin) at the time of injection molding described later can be maintained. The temperature is raised.
Further, a plunger or a screw (both not shown) for injecting the resin 50 is disposed in the cavity that is sealed by clamping the fixed mold 41 and the movable mold 42. The resin 50 is measured and heated. It is injected into the cavity in the molten state and filled into a space such as the assembly gap of the above-described constituent members.

Then, the manufacturing method of the rotor 10 for motors of a present Example is demonstrated in order of a work process with FIG.
First, the constituent members (the rotor core 20, the shaft 30, the permanent magnet 31, and the end plate 32) of the motor rotor 10 are assembled and set to the fixed mold 41 of the injection molding machine 40. At this time, when each component member is set on the fixed die 41, the rotor core 20 is set in a state where the respective assembly members are assembled, and the rotor core 20 in the state where the fixed member 41 is set. Each assembly member may be assembled in some cases, but these are appropriately selected in consideration of the assembly workability, and detailed description thereof is omitted.
Next, in a state where the constituent members are assembled and set to the fixed die 41, the movable die 42 is closed and clamped, and the entire constituent members are brought into a sealed state. A high frequency current is supplied to the heating coil 44 by the frequency conversion control unit of the electromagnetic induction heating device 43. As a result, the component member is efficiently heated and heated by the electromagnetic induction action from the heating coil 44, and becomes a high temperature state in which the fluidity of the resin 50 can be maintained.
Next, the molten resin 50 is injected into the cavity formed by mold clamping. As a result, as shown in FIG. 1, the injected resin 50 in the molten state has an assembly gap or the like between the constituent members heated to a temperature at which the fluidity of the resin 50 can be maintained. The space is filled. Specifically, the melted resin 50 has a gap (not shown) formed between the shaft slot 23 and the shaft 30 and a gap formed between the magnet slot 24 and the permanent magnet 31 (not shown). In the filling slot 25, the gap is formed between the laminated end face 22 of the rotor core 20 and the end plate 32, and the space in which the end plate 33 is formed is filled.
Then, the resin rotor 50 is then cured and demolded, whereby the motor rotor 10 having an integrated configuration is obtained.

Thus, according to the manufacturing method of the motor rotor 10 of the present embodiment, the constituent members of the motor rotor 10 as the insert member can be heat-treated in the mold of the injection molding machine 40. Therefore, as in the prior art, the process of heating and raising the component members to a temperature at which the fluidity of the molten resin 50 can be maintained in advance by separate equipment such as a high-temperature furnace becomes unnecessary. Therefore, space saving of the entire equipment can be achieved. Furthermore, the operation | work which puts in and takes out a structural member to a high temperature furnace can be skipped.
Furthermore, since it is no longer necessary to handle a high-temperature component that has been heated and heated during the work, the assembly workability and work safety can be improved. Furthermore, the component members can be heat-treated in the mold of the injection molding machine 40 until just before the stage of injecting the molten resin 50. Therefore, the injection molding of the resin 50 can be performed in a high temperature state in which the constituent members are heated to a temperature at which the fluidity of the molten resin 50 can be maintained, and the molding can be performed with high accuracy and stability.
In addition, since the components are heated by electromagnetic induction, the components of the motor rotor 10 can be efficiently heated and heated, and the molding cycle time can be shortened. In addition, since the temperature control of the constituent members can be performed with high accuracy, it is possible to easily control the target temperature (the temperature at which the fluidity of the molten resin 50 can be maintained).

Although the embodiment of the present invention has been described with respect to one example, the present invention can be implemented in various forms in addition to the above example.
That is, as a means for heating the fixed mold 41 and the movable mold 42 itself of the injection molding machine 40, a well-known electric heater or a mold temperature controller is used, but the constituent members of the motor rotor 10 and Similarly, heating may be performed by electromagnetic induction.
Moreover, although the thing using the electromagnetic induction heating apparatus 43 was shown as a heating means of a structural member, the above-mentioned electric heater and mold temperature controller set the structural member to a predetermined temperature (the temperature of the molten resin 50 at the time of injection molding). Any apparatus using these devices may be used as long as it has a structure capable of heating to a temperature capable of maintaining fluidity and curability. That is, when the conventional means for heating the fixed mold 41 and the movable mold 42 of the injection molding machine 40 described above is used as the means for heating the constituent members as they are, the constituent members are sufficiently heated. It is because it is not broken.
Furthermore, although what showed the temperature rising process in the state which clamped the structural member with the fixed mold | type 41 and the movable mold | type 42 of the injection molding machine 40 was shown, for example, the mold opening which assembled and set the structural member to the stationary mold | type 41 It may be one that is heated and heated in the state.

It is process drawing which showed the process state which heat-heats the structural member of the rotor for motors of a present Example within the type | mold of an injection molding machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Motor rotor 20 Rotor core 21 Magnetic steel plate 22 Laminated end face 23 Slot for shaft 24 Slot for magnet 25 Slot for filling 30 Shaft 31 Permanent magnet 32 End plate 33 End plate 40 Injection molding machine 41 Fixed type 42 Movable type 43 Electromagnetic induction heating device 44 Heating coil 50 Resin (filler)

Claims (2)

With the components of the motor rotor assembled and set in the mold of the injection molding machine, the assembly gap between the components is injected by injecting molten filler into the cavity formed by clamping the mold. In which the rotor for the motor is integrally formed,
Prior to injecting the filler, the components in a state assembled and set in the mold of the injection molding machine are subjected to the fluidity of the molten filler by heating means disposed in the injection molding machine. A method for producing a rotor for a motor, characterized in that the temperature of the motor is increased to a predetermined temperature at which the motor can be maintained. It is a manufacturing method of the rotor for motors according to claim 1,
The heating means is an electromagnetic induction heating device in which a heating coil is disposed in a mold of the injection molding machine, and the molten state filler is assembled by electromagnetic induction heating of a component member assembled and set in the mold. A method for producing a rotor for a motor, wherein the temperature is raised to a predetermined temperature at which the fluidity of the motor can be maintained.

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