JP2008154348A - Stator heating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stator heating method which can heat a fixed part in a short time, and can hold stable insulating performance without damaging a resin component which contacts with an insulator or the like. <P>SOLUTION: The stator heating method heats the stator by making AC currents flow to conductor coils 4 as pre-heating in a conductor coil resin-molding process for fixing the conductor coils 4 by filling and molding an insulating resin between the conductor coils 4 with respect to the stator in which the conductor coils 4 are wound to a stator core 3 constituted of laminated thin steel sheets. In the method, the stator is heated by a cope 1 having a space for accommodating the conductor coil 4 of the stator core 3, and a drag 2 having a space for accommodating the conductor coil 4 of the stator core 3 in a state that internal and external peripheral upper faces and internal and external peripheral lower faces of a conductor attachment part of the stator core 3 are sandwiched by the cope 1 and the drag 2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a stator in which a conductor coil is mounted on a stator core that is a component of a motor. More specifically, the conductor coil is fixed by filling and molding an insulating resin between the conductor coils, and the conductor coil The present invention relates to a stator heating method for heating a stator as preheating in a conductor coil resin molding step for radiating heat.

Conventionally, as a processing method for forming and fixing a conductor coil to a stator having a conductor core mounted on a stator core, a varnish impregnation method in which a varnish is cured by impregnating a varnish between conductor coils and heating, A resin molding method is performed in which an insulating resin is filled and molded between conductor coils by injection molding of a resin material using a material.
And, as a method of impregnating the varnish into the conductor coil, there are known a method of dripping and impregnating the varnish while rotating the stator, and an immersion method of impregnating the varnish by capillary action by immersing the lower part of the conductor coil in the varnish tank. ing. In any case, a preheating drying step for removing moisture and winding stress relaxation (annealing treatment) and a stator heating step for heating the conductor coil to cure the thermosetting resin are required before and after the molding step. .
Similarly, in the resin molding method, since a thermosetting type resin is generally used, the resin is cured if the stator is not heated when the stator is inserted into the mold and insert injection molding is performed. If the resin is a thermoplastic type, if the stator is not heated, the fluidity of the resin will deteriorate significantly, causing problems such as unfilling. And a stator heating step in which the stator core is uniformly heated in advance within a certain temperature range. For example, examples of the thermosetting resin include unsaturated polyester, epoxy, PPS, and LCP resins.

The stator is composed of a stator core and a conductor coil attached to the stator core. In particular, it is ideal that the entire conductor coil is uniformly heated in a short time. At least, the temperature distribution of the entire conductor coil needs to fall within a predetermined range in a short time. The method of heating the stator in a hot air heating furnace is good in that the entire stator is heated uniformly, but it takes too much time to heat from 20 ° C to 150 ° C, as it takes 80 minutes. Production efficiency is poor.
Here, since the conductor coil is provided with an insulation coating and has an electrical terminal, it can be easily heated by energization, but the stator core has no insulation coating and is difficult to energize, and also has a large heat capacity and a short time. It is difficult to heat with.
As a method of heating the stator core, Patent Document 1 discloses a method of heating the entire coil by supplying hot air to the drying furnace and simultaneously heating the coil by energizing the winding coil.
Further, in Patent Document 2, in order to shorten the heating time of the stator during the varnish treatment, by energizing the winding coil, the winding coil is heated by self-heating, and at the same time, fixed using the dielectric heating phenomenon. Techniques for heating the child core are described.
According to the method of Patent Document 1 and the method of Patent Document 2, it is known that the stator can be heated in a few minutes.

JP 2004-096876 A JP 2005-086954 A

However, the conventional stator heating method has the following problems.
That is, in the method of energizing and heating an electric wire coil, the electric wire coil wound with an electric wire as a conductor is energized, thereby generating heat to heat the electric wire coil. In this case, since an alternating current is normally applied, a magnetic field is generated by the alternating current, and a force is applied in the direction in which the thin steel plates stacked by the generated magnetic field are stacked. And since it is alternating current, since a magnetic field reverses 180 degree | times, the force which a thin steel plate receives from a magnetic field also receives the force reversed 180 degree | times. Due to this reversing force, the thin steel plate constituting the stator core vibrates although it is a minute amount. In particular, the minute vibrations of the thin steel plates positioned outside of the laminated thin steel plates are measured.
When the thin steel plate vibrates in a minute amount, the contact portion of the resin insulator or bus bar in contact with the thin steel plate may be rubbed and damaged. And when an insulator and a bus-bar are rubbed and scraped and damaged, since insulating resin will become thin, there existed a problem which insulating property fell.

  Here, it is known that if a direct current is applied without applying an alternating current, vibration does not occur and the problem can be solved. However, in order to heat the stator in a short time, it is necessary to pass a large current, and a device that generates a large direct current is expensive and has a problem with durability. It is unsuitable for heating the stator.

  The present invention has been made to solve the above-described problems, and its purpose is to heat the fixing in a short time, and to provide stable insulation performance without damaging the resin parts that come into contact, such as an insulator. It is providing the stator heating method which can be hold | maintained.

In order to achieve the above object, the stator heating method of the present invention includes the following steps.
(1) Conductor coil resin for fixing a conductor coil by filling and molding an insulating resin between the conductor coils for a stator in which a conductor coil is mounted on a stator core formed by laminating thin steel plates. A stator heating method for heating a stator by passing an alternating current through a conductor coil as pre-heating in a molding process, wherein an upper mold in which a space for accommodating a conductor coil of a stator core is formed, and a stator Fixed in a state where the inner and outer peripheral upper surfaces and inner and outer peripheral lower surfaces of the stator core's conductor mounting part are sandwiched between the lower mold in which a space for storing the core conductor coil is formed, and the upper mold and the lower mold. The child is heated.

(2) In the stator heating method described in (1), a portion of the insulator or bus bar exposed to the outside of the stator core is pressed to the upper mold or the lower mold.
(3) In the stator heating method described in (1) or (2), a heater is provided at a position sandwiching an outer peripheral portion of the conductor mounting portion of at least one of the upper die and the lower die. It is characterized by.

The operation and effect of the stator heating method having the above configuration will be described.
When an alternating current is passed through the conductor coil, a magnetic field is generated by the alternating current, and a force is applied in the direction in which the thin steel plates stacked by the generated magnetic field are stacked. And since it is alternating current, since a magnetic field reverses 180 degree | times, the force which a thin steel plate receives from a magnetic field also receives the force reversed 180 degree | times.
However, because the stator is heated with the inner and outer peripheral upper surfaces and inner and outer peripheral lower surfaces of the stator core of the thin steel plate laminated in the upper mold and lower mold sandwiched between the upper and lower molds, respectively. The laminated steel sheet does not vibrate slightly. Therefore, there is no possibility that the contact portion of the resin insulator or bus bar that is in contact with the thin steel plate caused by microvibration of the laminated steel plate is rubbed and damaged. In addition, a space for accommodating the stator core conductor coil is formed in the upper mold, and a space for accommodating the stator core conductor coil is formed in the lower mold, so that the stator is sandwiched between the upper mold and the lower mold. Since the conductor coil is inside the storage space constituted by the upper mold and the lower mold in the depressed state, it is possible to reduce the escape of heat from the conductor coil. That is, since the air in the storage space is confined and cannot circulate, the temperature immediately rises and the amount of heat radiated from the conductor coil to the air is reduced.

Also, when energized and heated with the laminated steel sheet sandwiched between the upper mold and the lower mold, it is exposed to the outside of the stator coil, and the insulators and bus bars in the free state pick up minute vibrations of the laminated steel sheet, There is a slight risk of vibration. Even if the insulator and the bus bar vibrate slightly, there is a risk that the insulator and the bus bar may be damaged by rubbing between the laminated steel plates.
However, in the present invention, since the portion of the insulator or bus bar exposed to the outside of the stator core is pressed, it is possible to prevent the insulator or bus bar from vibrating even a little, so that there is no risk of damage to the insulator or bus bar.

Since the conductor coil is mounted in the slot provided in the inner peripheral portion of the laminated steel plate, the inner peripheral side of the laminated coil is easily heated and immediately reaches a target temperature (for example, 130 ° C. to 140 ° C.). However, since the outer peripheral portion of the laminated steel plate is far from the conductor coil and has a large volume, it takes time to heat to the target temperature.
In order to solve this problem, in the present invention, since the heater is provided at a position for sandwiching the outer peripheral portion of the conductor mounting portion of at least one of the upper mold and the lower mold, the outer peripheral portion of the laminated steel sheet is sandwiched. In this state, since the outer peripheral portion of the laminated steel plate can be directly heated by the heater, the outer peripheral portion of the laminated steel plate can be heated in a short time.

A method for heating a stator according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a cross-sectional view of the stator in a state sandwiched between an upper mold 1 and a lower mold 2 used in the stator heating method.
The stator core 3 is formed by stacking several tens of steel plates 3a having a thickness of about 0.3 mm to form a stator core 3 made of laminated steel plates. The total thickness of the stator core 3 is 26 mm. On the inner peripheral surface of the stator core 3, quadrangular protrusions protrude toward the center at 12 locations. A hollow hole of an insulator 5 around which a conductor coil 4 made of a nichrome-coated copper wire is wound is mounted on the convex portion. A bus bar 6 is connected to a terminal portion of the body coil 4 protruding outside the insulator 5.

The shape of the insulator 5 is shown in a perspective view in FIG. The shape of the bus bar 6 is shown in a perspective view in FIG. The insulator 5 is made of resin to ensure insulation, walls 5c and 5d are formed at both ends of the hollow portion 5a, and the conductor coil 4 is wound around the outer peripheral portion 5b of the hollow portion 5a between the walls 5c and 5d. . The portion around which the conductor coil 4 is wound is thin so long as it can ensure insulation. As shown in FIG. 2, the convex portion of the stator core 3 enters the hollow of the insulator 5 in a state assembled as a stator. Here, when the stator core 3 vibrates, the outer peripheral portion 5b of the hollow portion 5a of the insulator 5 is scraped off, and the insulating property of the insulator 5 may be impaired.
The bus bar 6 is for wiring the conductor coils 4 wound around the twelve insulators 5, and each conductor coil 4 is connected to the three phases U, V, and W to form a three-phase coil. A connector 6a for connecting them to the outside is provided.

Next, the structure of the lower mold 2 will be described. The lower mold 2 is made of hollow cylindrical aluminum. On the upper surface of the lower mold 2, a groove-shaped lower mold storage portion 2a is formed over the entire circumference. In the lower mold housing part 2a, a lower mold insulator pressing part 2e is formed over the entire circumference. The lower mold insulator pressing portion 2e has a function of pressing the insulator by just contacting the lower surface of the outer wall 5d of the insulator 5 when the stator is mounted on the lower mold 2. The width | variety of the lower mold | type storage part 2a is a width | variety with which the wall 5c contacts the inner peripheral wall of the lower mold | type storage part 2a, when the lower mold | type insulator presser part 2e is contact | abutting with the wall 5d of the insulator 5. FIG.
The inner peripheral part forming the lower mold accommodating part 2a constitutes the lower mold inner peripheral upper presser part 2c. Moreover, the outer peripheral part which forms the lower mold | type storage part 2a comprises the lower mold | type outer peripheral upper surface pressing part 2b. The lower mold inner periphery upper presser portion 2c supports, from the lower side, the tip portions of the twelve convex portions of the stator core 3, that is, the convex portion tip portion that protrudes slightly through the hollow portion of the insulator 5. Yes. The lower mold outer peripheral upper surface pressing portion 2 b supports the lower surface of the outer peripheral portion of the stator core 3. Heaters 7 are attached to the lower mold outer peripheral upper surface pressing portion 2b at several locations. In this embodiment, the heater is provided only in the lower mold outer periphery pressing portion 2b, but a heater may be provided in the upper die outer periphery lower surface pressing portion 1b.

Next, the structure of the upper mold 1 will be described. The upper die 1 is made of hollow cylindrical aluminum having the same size as the lower die 2. On the lower surface of the upper mold 1, a groove-shaped upper mold storage portion 1a is formed over the entire circumference. In the upper mold housing part 1a, an upper mold insulator pressing part 1e is formed over the entire circumference. The upper part of the outer peripheral wall 5 d of the insulator 5 protrudes upward to support the end wiring of the conductor coil 4. In order to abut and press against this, the upper mold insulator pressing portion 1e is different in shape from the lower mold insulator pressing portion 2e and is a small convex portion.
The inner peripheral surface of the upper mold accommodating portion 1a is at the same position as the lower mold accommodating portion 2a, but the outer peripheral surface is at a position outside the lower mold accommodating portion 2a in order to accommodate the connector 6a of the bus bar 6.

The inner peripheral part forming the upper mold accommodating part 1a constitutes the upper mold inner peripheral lower presser part 1c. Moreover, the outer peripheral part which forms the upper mold | type storage part 1a comprises the upper mold | type outer periphery lower surface pressing part 1b. The upper mold inner periphery lower presser portion 1c supports the tip portions of the twelve convex portions of the stator core 3, that is, the convex tip portions that protrude slightly through the hollow portion of the insulator 5. . The upper mold outer peripheral lower surface pressing portion 1 b supports the upper surface of the outer peripheral portion of the stator core 3.
The upper mold accommodating portion 1a is formed with a bus bar pressing portion 1f for pressing the bus bar 6 from above and sandwiching it with the stator core 3. The connector 6a of the bus bar 6 is provided at one place of the stator. The connector 6a has a notch formed in the upper mold 1 so as to come out of the upper mold 1.

Next, the effect | action which energizes and heats the conductor coil 4 by accommodating a stator in the space formed with the upper mold | type accommodating part 1a and the lower mold | type accommodating part 2a which have the said structure is demonstrated.
A heating power connector (not shown) is connected to the connector 6 a of the bus bar 6.
As shown in the head 1, the outer periphery of the stator core 3 formed by laminating steel plates in a state where the stator is fixed in a space formed by the upper mold storage portion 1 a and the lower mold storage portion 2 a It is sandwiched between the outer peripheral upper surface pressing portion 1b and the lower mold outer peripheral upper surface pressing portion 2b and is pressed by the weight of the upper die 1. Moreover, the convex part of the inner periphery of the stator core 3 is sandwiched between the upper mold inner periphery upper presser part 1c and the lower mold inner periphery upper presser part 2c and is pressed by the weight of the upper mold 1 itself.
Further, the outer wall 5d of the insulator 5 is sandwiched between the upper mold insulator pressing portion 1e and the lower mold insulator pressing portion 2e and pressed by the weight of the upper mold 1 itself. The inner wall 5c of the insulator 5 is in close contact with the inner peripheral surface of the upper mold outer peripheral upper surface pressing portion 1b and the inner peripheral surface of the lower mold outer peripheral upper surface pressing portion 2b. It is sandwiched between and pressed down.
The bus bar 6 is sandwiched and pressed between the bus bar presser portion 1 f and the upper surface of the stator core 3.

In such a state, a three-phase alternating current is applied to the conductor coil 4 to cause the conductor coil 4 to generate heat due to resistance. Thereby, the conductor coil 4 and the stator core 3 are heated.
When a three-phase alternating current is passed through the conductor coil 4, a magnetic field is generated by the alternating current, and a force is applied in the direction in which the thin steel plates on which the stator cores 3 are stacked are stacked. And since it is alternating current, since a magnetic field reverses 180 degree | times, the force which a thin steel plate receives from a magnetic field also receives the force reversed 180 degree | times. By this reversing force, the thin steel plate constituting the stator core receives a force that vibrates in the vertical direction.
However, the outer peripheral portion of the stator core is sandwiched by the upper die outer peripheral upper surface pressing portion 1b and the lower die outer peripheral upper surface pressing portion 2b and is held by the own weight of the upper die 1 so that it does not vibrate. Moreover, the convex part of the inner periphery of the stator core 3 vibrates because it is sandwiched between the upper mold inner periphery upper presser part 1c and the lower mold inner periphery upper presser part 2c and is held by the own weight of the upper mold 1. There is nothing.

The outer wall 5d of the insulator 5 is sandwiched between the upper mold insulator pressing portion 1e and the lower mold insulator pressing portion 2e and is held by the weight of the upper mold 1, and the inner wall 5c of the insulator 5 is The inner peripheral surface of the die outer peripheral lower surface pressing portion 1b and the inner peripheral surface of the lower die outer peripheral upper surface pressing portion 2b are in close contact with each other and are sandwiched and pressed between the inner peripheral surface and the stator core 3, so that the insulator 5 Does not vibrate with respect to the stator core 3.
Further, since the bus bar 6 is sandwiched and pressed between the bus bar pressing portion 1 f and the upper surface of the stator core 3, the bus bar 6 does not vibrate with respect to the stator core 3.

The vibration of the stator core 3 has been confirmed by experiments. That is, the generation of sound was measured when the stator core 3 was in a free state and when the stator core 3 was held between the upper mold 1 and the lower mold 2 and pressed. Originally, it is better to directly measure the vibration, but since the vibration of the stator core 3 is small, there is a possibility that accurate vibration cannot be measured if a vibration sensor is attached. . FIG. 5 shows the result.
In a state where there is no press, the noise of 91.0 dB is reduced to 79.7 dB by providing the press. Here, the background noise was 55 to 60 dB.
Thus, 11 dB was also effective in reducing vibration (noise).

Further, when the conductor coil 4 is energized to heat the entire stator, the entire stator is placed in a space formed by the upper mold housing portion 1a of the upper mold 1 and the lower mold housing section 2a of the lower mold 2. Since heating is performed in a confined state, heat is less likely to dissipate into the air, and the heating time can be shortened.
Furthermore, generally, when the conductor coil 4 is energized and heated, the heat generated in the conductor coil 4 is quickly conducted to the stator core 3, so that the inner peripheral portion of the stator core 3 close to the conductor coil 4 is Although the temperature rises relatively quickly, the temperature rise at the outer peripheral portion of the stator core 3 tends to be slower than that at the inner peripheral portion. In this embodiment, the heater 7 is provided in either one or both of the lower mold outer periphery upper presser portion 2b and the upper mold outer periphery lower presser portion 1b of the lower mold 2, so that the overall temperature rise time can be shortened. it can.

  As described in detail above, according to the stator heating method of the present invention, the distance between the conductor coils 4 with respect to the stator in which the conductor coils 4 are mounted on the stator core 3 formed by laminating thin steel plates. A stator heating method in which a stator is heated by passing an alternating current through the conductor coil 4 as preheating of the conductor coil resin molding step for fixing the conductor coil 4 by filling and molding an insulating resin. The upper mold 1 in which a space for accommodating the conductor coil 4 of the stator core 3 is formed, the lower mold 2 in which the space for accommodating the conductor coil 4 of the stator core 3 is formed, the upper mold 1 and the lower mold 2 And the stator is heated with the inner and outer peripheral upper surfaces and the inner and outer peripheral lower surfaces of the conductor mounting portion of the stator core 3 sandwiched between them. Force in the vertical direction of the stator core by the magnetic field It is applied, since no thin plate of the stator core 3 is vibrated, never insulator 5 may be damaged.

Further, since the upper die 1 or the lower die 2 holds the portion of the insulator 5 or bus bar 6 exposed to the outside of the stator core 3, the insulator 5 or bus bar 6 does not vibrate with respect to the stator core 3. The insulator 5 is not damaged.
Further, a heater 7 is provided on the lower mold outer peripheral upper surface pressing part 2b or the upper mold outer peripheral lower surface pressing part 1b, which is a position sandwiching the outer peripheral part of the conductor mounting part of at least one of the upper mold 1 and the lower mold 2. Therefore, since the outer peripheral part of the stator core 3 with the slowest temperature increase can be directly heated by energization heating, the heating time can be shortened.

In addition, this invention is not limited to each said embodiment, It can also implement by changing a part of structure suitably in the range which does not deviate from the meaning of invention.
For example, in this embodiment, the upper mold 1 and the lower mold 2 hold the stator core 3 and press it with only the weight of the upper mold 1. May be placed, or a pressurizing force may be applied by an air cylinder or the like.
In this embodiment, since the temperature rise is slow at the outer periphery of the stator core 3, the heaters 7 are provided at the portions of the upper mold 1 and the lower mold 2 at positions corresponding to the outer periphery. Depending on the shape, the position of the conductor coil 4 and the like, there is a possibility that the temperature of another part of the stator core 3 is slow to rise. In that case, you may provide a heater in the position of the upper mold | type 1 or the lower mold | type 2 corresponding to a site | part with a slow temperature rise among the stator cores 3. FIG.

3 is a cross-sectional view showing a configuration of a stator housed in an upper mold 1 and a lower mold 2. FIG. It is a perspective view which shows the whole structure of a stator. 3 is a perspective view showing a configuration of an insulator 5. FIG. 3 is a perspective view showing a configuration of a bus bar 6. FIG. It is a data figure which shows an experimental result.

Explanation of symbols

1 Upper mold 1a Upper mold storage part 2b Lower mold outer peripheral upper surface pressing part 2c Lower mold inner peripheral upper presser part 1e Upper mold insulator pressing part 1f Bus bar presser part 2 Lower mold 2a Lower mold storage part 2b Lower mold outer peripheral upper surface pressing part 2c Lower Mold inner periphery upper presser part 2e Lower mold insulator presser part 3 Stator core 4 Conductor coil 5 Insulator 6 Bus bar 7 Heater

Claims (3)

Conductor coil resin molding for fixing the conductor coil by filling and molding an insulating resin between the conductor coils for a stator having a conductor core mounted on a stator core formed by laminating thin steel plates In the stator heating method of heating the stator by passing an alternating current through the conductor coil as preheating of the process,
An upper mold in which a space for accommodating the conductor coil of the stator core is formed;
A lower mold in which a space for accommodating the conductor coil of the stator core is formed;
The stator is heated with the upper die and the lower die sandwiching the inner and outer peripheral upper surfaces and the inner and outer peripheral lower surfaces of the conductor mounting portion of the stator core, respectively. Child heating method. In the stator heating method according to claim 1,
A method of heating a stator, wherein a portion of the insulator or bus bar exposed to the outside of the stator core is pressed against the upper die or the lower die. In the stator heating method according to claim 1 or 2,
A stator heating method, wherein a heater is provided at a position sandwiching an outer peripheral portion of the conductor mounting portion of at least one of the upper die and the lower die.

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