JP2003125563A - Connection method for segment coil used in motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a segment coil connection method which does not need equipment for heating and can improve the working efficiency. SOLUTION: STEP51 is an initial position setting process, in which the position of a welding torch 15 is set at an initial welding position 13. STEP53 is a successive welding process, which comprises successive welding processes STEP531-STEP539. STEP55 is a melting adhesion process which must be carried out within a period, for instance three minutes, since the start of welding, while a temperature raised by welding heat is sufficiently higher than a melting adhesion lower-limit temperature of thermosetting resin. STEP57 is the heat-curing process, in which the thermosetting resin adhering by melting is heated under the thermal curing conditions for converting the thermosetting resin film into an insulating film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of connecting segment coils used in a motor, and more particularly, to welding of welding points of a segment coil and a method of forming an insulating film on the welded portion.

[0002]

Segment coils are used to facilitate the coil winding process of a motor stator or rotor. FIG. 8 is a diagram in which a cross section of a stator 1 of such a motor is developed in the circumferential direction, and the stator 1 is provided with a plurality of slots 3 for accommodating coils at a constant pitch. In FIG. 8, as an example, in the case of so-called distributed winding, the case where one stator winding 5 is sequentially arranged every three slots 3 is shown. A segment coil 7A made of a substantially U-shaped insulating conductor covered with an insulation has both legs thereof inserted into a slot 3 separated by three slots, both legs are bent, and has both ends 9A and 9B as shown by a broken line. It becomes a structure. Similarly, the segment coils 7B and 7C are arranged adjacent to each other, one end 9A of the segment coil 7A and one end 9C of the segment coil 7B are connected, and the other end 9B of the segment coil 7A and the segment coil 7C are connected. Connect one end 9D to connect the segment coil 7
B, 7A, and 7C have a continuous structure.

By repeating this once in the circumferential direction of the stator 1, one stator winding 5 is arranged in the slots 3 every three slots. Repeat this,
A predetermined number of stator windings 5 are arranged in each slot, and the stator 1 has a structure using segment coils.

9A to 9C show examples of the prior art regarding the method of connecting the ends of the segment coil. In order to connect the ends, as a pretreatment, a segment coil, for example, an enamel coating of an enamel copper wire is peeled off at the ends, and the ends are aligned to be welded points.

FIG. 9 (a) is a view showing a welding process. One surface of the annular stator 11 is, for example, 48 in the circumferential direction.
The welding torch 15 sequentially performs welding on the row, and four welded points 13 arranged in total in the radial direction of each row. The position of the welding torch 15 is set to the first welding point, welding is performed, and the position of the welding torch 15 remains fixed, the stator 11 is rotated, and the welding torch 15 is moved to the next welding point in the circumferential direction. Move relative to the next welding.
When the welding of 48 points in the circumferential direction is completed, the welding torch 1
5 is moved in the radial direction to the next welded point in the radial direction.
The above procedure is repeated to weld 192 points in total.

FIG. 9 (b) is a diagram showing a heating process, in which the stator 11 after welding is heated in a heating furnace 17 to, for example, 17
Heat at 0 ° C for 4 hours.

FIG. 9 (c) is a diagram showing a melt adhesion process.
The heated stator 11 is immersed in the powder immersion tank 19,
A thermosetting resin is melted and adhered to the welded portion 13. The powder immersion tank 19 has a porous partition plate 21 having holes of, for example, several μm inside the tank, and has a melting point of around 100 ° C. in the immersion part 23 above the partition plate 21. A thermosetting resin powder having a diameter of 10 to 30 μm, such as an epoxy resin, is supplied. When air is sent through the air inlet 25 at the lower part of the partition plate 21, the powder is separated from the partition plate 2.
At the upper part of 1, it rolls up moderately and flows. Powder immersion tank 19
The heated stator 11 is moved to the upper part of and is lowered to be placed at a height at which the end of the segment coil is immersed in the flowing powder, so that the powder is heated to the melting point or higher. Touch the edges to melt and adhere.

Thereafter, although not shown, the stator having the thermosetting resin melted and adhered to the end of the segment coil is heat-treated at a temperature higher than the curing temperature and thermally cured to form an insulating film on the end of the segment coil. Form. In this way, the segment coils are connected.

[0009]

As described above, the segment coil connection method of the prior art can connect the segment coils used in the motor. However, in the prior art, since it is necessary to heat the entire welded stator, it takes about 4 hours per heating time, work efficiency is poor, and a large number of heating facilities and electric power are required for mass production. did.

An object of the present invention is to solve the problems of the prior art and to provide a method for connecting segment coils which does not require heating equipment and which has good working efficiency.

[0011]

According to the method of connecting segment coils of the present invention, in order to melt-adhere the thermosetting resin to the ends of the segment coil, only the ends of the segment coil have a melting point higher than the melting point of the thermosetting resin. It is based on the finding that the residual heat can be utilized under a certain condition when the change in the residual heat temperature due to welding of the welded portion is examined.

In FIG. 1, for example, electromagnetic steel sheets having a size of an outer diameter of about 30 cm, an inner diameter of about 20 cm, and a thickness of about 10 cm are laminated, and 192 points of a stator using a segment coil of an enamel-coated copper wire are covered. It is the figure which showed typically the change of the residual heat temperature by welding in the room temperature atmosphere of the welding part when welding a welding point one by one. The temperature of the welded portion immediately after welding is determined by the melting point of the copper wire and the like, and reaches about 1000 ° C. The temperature of the welded portion rapidly decreases in a room temperature atmosphere, but for example, it takes about 5 minutes to lower the melt adhesion lower limit temperature of the epoxy resin powder, which is about 100 degrees C. For example, it takes about 3 minutes to decrease to 180 ° C. This cooling curve is determined by the heat capacity around the segment coil, the heat flow path, etc., and becomes a constant cooling curve when the stator is determined. On the other hand, the time required for welding the 192 points is about 45 seconds, and the time required for the epoxy resin powder to be melted and adhered is about 5 seconds.

As described above, it is clear that the time required for welding and the time required for melt adhesion are sufficiently shorter than the time for the residual heat temperature to drop from about 1000 ° C immediately after welding to 100 ° C, which is the lower limit temperature for melt adhesion. It was Therefore, it was found that it is possible to melt-adhere the thermosetting resin within the melt-adhesion-enabled period until the residual heat temperature due to welding of the welded portion falls below a predetermined temperature according to the melting point of the thermosetting resin. It was

When welding is sequentially performed on 192 points to be welded, the first welded portion is along the cooling curve a, and the points A-B-C and the last welded portion are the cooling curve b. Along the road, the temperature drops to point D-E-F. Since there is a difference in the temperature of each welding point in this way, there is a possibility that a difference in the film thickness of the insulating film will occur if the amount of melted and adhered differs depending on the temperature. Therefore, in order to improve the film thickness uniformity, it is necessary to perform the melt adhesion in a state where the temperature difference between the welded portions is small.

In order to achieve the above object of the present invention, a method for connecting segment coils according to the present invention is provided with a plurality of rows in a circumferential direction of a stator or a rotor and a predetermined number of segment coils to be welded in a radial direction. A method of connecting segment coils, comprising welding, and melting and adhering a thermosetting resin to the welded portion to form an insulating film, in which a welding torch moves relative to the stator or rotor and A welding process of sequentially welding points, and a residual heat temperature due to the welding of the welded portion is melted to attach the thermosetting resin within a melt attachable period of a predetermined temperature or more according to the melting point of the thermosetting resin. The method is characterized by including an attaching step and a thermosetting step of heat-treating the attached thermosetting resin to form an insulating film.

In the segment coil connecting method according to the present invention, the predetermined temperature is 100 ° C. or higher and 18
It is preferably 0 degrees C or less.

Further, in the segment coil connection method according to the present invention, it is preferable that the melt adhesion period is within 3 minutes from the start of the welding.

Further, the segment coil connecting method according to the present invention is such that a plurality of rows in the circumferential direction of the stator or rotor are welded at a predetermined number of segment coils in the radial direction, and the welding points of the segment coils are welded. A method of connecting segment coils, wherein a curable resin is melted and adhered to form an insulating film, wherein a welding torch moves in the radial direction of the stator or rotor and a predetermined number of the welded torch are provided in the radial direction. A radial row welding step of sequentially welding the spots by one row, a radial row melt adhesion step of melting and adhering the thermosetting resin to the radial welding row portion, and a heat treatment of the adhered thermosetting resin And a heat curing step of forming an insulating film.

Further, the segment coil connecting method according to the present invention welds a plurality of rows in the circumferential direction of the stator or the rotor and a predetermined number of the radial portions of the segment coil to be welded, and heats the welded portion. A method of connecting segment coils, in which a curable resin is melted and adhered to form an insulating film, wherein a welding torch moves relative to the stator or rotor, and a welding step of sequentially welding the welded points, and A heat-melting and adhering step of sequentially injecting the thermosetting resin onto the welded portion, and a thermosetting step of heat-treating the adhered thermosetting resin to form an insulating film. .

As described above, in the segment coil connecting method according to the present invention, the residual heat temperature due to the welding of the welded portion is within a predetermined period during which the residual heat can be melted and adhered to a predetermined temperature or lower according to the melting point of the thermosetting resin. Since the thermosetting resin is attached, the equipment for heating is not required and the segment coil can be connected with good working efficiency.

Further, since the thermosetting resin is sequentially injected after the welded points are sequentially welded, after the welding of one welded point, the thermosetting resin is injected to one of the welded points to obtain a sufficiently high residual heat. Melt deposition can be performed under temperature, and the film thickness of the insulating film between the welded portions can be made even more uniform.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. The same elements as those in FIG. 9 are denoted by the same reference numerals and the description thereof will be omitted. FIG. 2 shows a flow chart for the first embodiment. In the first embodiment, as shown in FIG. 1, a method in which a welded portion is fluidized and dipped in a welded portion during a period in which a temperature due to residual heat of welding is sufficiently higher than a melt adhesion lower limit temperature of the thermosetting resin. Is.

STEP 51 is an initial position setting step for setting the position of the welding torch at the first welding point. For example, it is set at the position of the welding point on the innermost peripheral side.

STEP 53 is from ST531 to ST.
It is a sequential welding process shown in EP539.

STEP 531 is a single point welding process. FIG. 3 shows the structure near the welded point 13. Welding torch 1
5 is arranged below the welded point 13 with a slight distance. The welded point 13 is a portion where the insulating coatings of the segment coils 7A and 7B are peeled off and the ends are arranged in contact with and aligned with the earthing claw 27 for welding.
A high voltage is applied between the welding torch 15 and the high voltage source 29. Then, an electric discharge occurs between the welding torch 15 and the welding point 13, and the welding point 13 is melted and joined.

STEP531, STEP533, STE
The process of returning to STEP 531 again after P537 is a circumferential direction sequential welding process. After the one-point welding step in STEP531, in the one-round welding completion determining step in STEP533, it is determined whether or not one round of welding in the circumferential direction of the stator 11, for example, 48 weldings has been completed. Until 48 pieces for one turn are completed, the process proceeds to the circumferential direction moving step of STEP 537, the work, in this case, the stator 11 is rotated in the circumferential direction by the distance between the welding points, and the welding torch 1 is attached to the next welding point 13.
5 is moved relatively. Instead of rotating the work, the welding torch 15 may be moved. Welding torch 15
When the position of is set to the next welded point 13, ST
Return to the single-point welding process of EP531. In this way, ST
After EP531, STEP533, and STEP537, the process of returning to STEP531 is repeated, and welding is sequentially performed in the circumferential direction.

When it is determined in STEP533 that the welding for one round is completed, the welding for one round is completed, STEP53
In the step 5 of determining all welding completion, it is further determined whether or not all welding, for example, 48 weldings per round for 4 rows, 192 weldings in total, are completed. Until all welding is completed,
Proceeding to the radial movement process of STEP535, welding torch 1
5 is moved to the outer peripheral side along the radial direction of the stator 11 by the distance between the welding points, and is relatively moved to the position of the next welding point 13. When the position of the welding torch 15 is set to the next welding point 13, the process returns to STEP 531 and welding is performed again sequentially in the circumferential direction. When this process is repeated and all the welding is completed, the welding process ends and the process proceeds to STEP 55.

STEP 55 is the STE in the melt adhesion process.
When it is determined in P535 that all welding is completed, the welded portion of the stator 11 after welding is immersed in the powder immersion tank 19 and the thermosetting resin is melted and adhered. As already described in FIG. 1, it is necessary to carry out the melt adhesion step within 3 minutes from the start of welding. The powder immersion tank 19 is supplied with, for example, epoxy resin powder having a melting point of about 100 degrees C.

STEP 57 is a thermosetting process in which the stator, which has undergone the melt adhesion process, is heated so as to satisfy the thermosetting conditions, and the melt adhered thermosetting resin is thermally cured to form an insulating film. For example, it heats at 170 degreeC for 30 minutes.

In this manner, while the temperature due to the residual heat of welding is sufficiently higher than the lower limit temperature for melting and adhering the thermosetting resin, the thermosetting resin is fluidized and dipped in the welded portion to form an insulating film, The segment coils can be connected, the production lead time can be significantly shortened, and the facility cost can be reduced.

FIG. 4 is an explanatory diagram of the second embodiment. In this case, a predetermined number of, for example, four welded points 13 arranged in a row in the radial direction of the stator 11 are sequentially welded to form a welded row. After that, the small powder immersion tank 31 moves to the position of the welding row, rises at that position, and the four welding rows are dipped as one unit to melt and adhere the thermosetting resin to the welding row. Movable small powder immersion tank 31
Has a dipping portion necessary and sufficient for dipping the welding row, and its structure is similar to that of the large-sized powder dipping tank 19.

FIG. 5 is a diagram showing a flow chart of the second embodiment.

STEP 61 is an initial position setting step for setting the position of the welding torch 15 to the first welded point 13. For example, it is set at the position of the welded point 13 on the innermost peripheral side of the stator 11.

STEP 63 has a predetermined number in a row in the radial direction,
For example, the welded points 13 arranged four are sequentially welded,
It is a radial row welding process of forming a weld row. When the welding of one welding point is completed, the welding torch 15 is moved to the stator 11
Along the radial direction of, move to the outer peripheral side by the distance between one welding point,
The welding is performed by setting the position of the next welded point 13.

In STEP 65, welding is completed for all the welded points 13 arranged in a predetermined number in a row in the radial direction.
When the welding row is formed, the work, that is, the stator 11 is rotated in the circumferential direction by the distance between the welding points, and the welding torch 13
Is a circumferential movement step of moving the to the position of the welded point 13 in the next row.

In STEP 67, after the welding torch 15 moves in the circumferential direction, the small powder immersion tank 31 moves to the position of the welding row, rises at that position, and the welding row is immersed as one unit. It is a radial fusion adhesion step of melting and adhering a thermosetting resin.

STEP 69 is a melt adhesion completion judging step for judging whether or not the melt adhesion is completed. If it is judged that the melt adhesion has not been completed, STEP 63
Return and perform radial row welding.

STEP 71 is the same as STEP 69.
When it is determined that all the melt adhesion has been completed, the stator after the melt adhesion process is finished is heated so as to satisfy the heat curing condition, and the melt adhered thermosetting resin is thermally cured to form the insulating film. This is a heat curing step.

In this way, a predetermined number of welded points arranged in a line in the radial direction are welded to form a weld line, and the above-mentioned thermosetting resin is melted and adhered to the weld line as one unit. The temperature difference between the welded portions can be further reduced, and the thickness of the insulating film can be made more uniform. In addition, by using a movable small-sized powder immersion tank, it is not necessary to provide a heavy stator up-and-down mechanism for immersion in the powder immersion tank, and the equipment cost can be reduced.

FIG. 6 is a diagram for explaining the third embodiment. In this case, the welding torch 15 has one welded point 1
After sequentially welding 3, the injection nozzle 33 sequentially injects the thermosetting resin to the welded portion. The injection nozzle 33 is
The structure is such that the thermosetting resin powder can be injected in a predetermined amount in a predetermined range.

FIG. 7 is a diagram showing a flow chart of the third embodiment. STEP 81 is an initial position setting step of initially setting the position of the welding torch 15.

STEP 83 is a welding process for welding one welded point 13. STEP85 is welding torch 1
5 is a moving step of moving 5 to the next welded point 13. These steps correspond to the STE of FIG. 2 in the case of the first embodiment.
P51, STEP531, STEP533, STEP5
It can be performed similarly to 37.

In STEP 87, after the welding torch 15 has finished welding one piece and moved to the next welding point, the injection nozzle 33 injects the thermosetting resin and melts and adheres it to the welding portion. Is.

STEP 89 is an all-melt-adhesion completion determining step of determining whether or not the welding and the melt-adhesion by injection of the thermosetting resin have been completed for all the welded points.
When it is judged that all are not completed, STEP83
Return to and weld.

STEP 91 is the same as STEP 89.
When it is determined that all the melt adhesion is completed, the stator after the melt adhesion process is heated so as to satisfy the thermosetting condition, and the melt adhered thermosetting resin is thermally cured to form the insulating film. This is a heat curing step.

In this way, after welding one welded point, the thermosetting resin is sprayed each time, and the melt adhesion can be performed while there is sufficient residual heat. Can be made even more uniform.

In the above description, the stator using the segment coil is taken up for the sake of convenience, but the present invention can also be applied to a rotor using the segment coil.

[0048]

EFFECT OF THE INVENTION The segment coil connecting method according to the present invention requires no equipment for heating and enables the segment coils to be connected with good work efficiency.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a change in residual heat temperature due to welding in a room temperature atmosphere of a welded portion, which is the basis of the knowledge of the present invention.

FIG. 2 is a flowchart showing a first embodiment of the present invention.

FIG. 3 is a diagram showing a configuration near a welded point in a welding process.

FIG. 4 is an explanatory diagram of a second embodiment of the present invention.

FIG. 5 is a diagram showing a flowchart of a second embodiment of the present invention.

FIG. 6 is a diagram illustrating a third embodiment of the present invention.

FIG. 7 is a diagram showing a flowchart of a third embodiment of the present invention.

FIG. 8 is a diagram showing a cross section of a stator of a motor in which a segment coil is used, which is developed in a circumferential direction.

FIG. 9 is a diagram showing an example of a conventional technique regarding a connection method between segment coil ends, in which (a) is a welding process and (b) is
[Fig. 3] is a diagram illustrating a heating process, and (c) is a diagram illustrating a melt adhesion process.

[Explanation of symbols]

1 stator, 3 slots, 5 stator windings, 7
A, 7B, 7C segment coil, 9A, 9B, 9
C, 9D end, 11 stator, 17 heating furnace, 19
Powder immersion tank, 21 Porous partition plate, 23 Immersion part, 25 Air inlet, 27 Earthing claw for welding, 29
High voltage source, 31 Small powder immersion tank, 33 injection nozzle.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yasuhiko Ishimaru             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd. F-term (reference) 5H603 AA03 AA09 BB01 BB12 CA01                       CA02 CB02 CB03 CB18 CB19                       CB23 CB25 CC03 CC17 CD06                       CD22 CE02 EE01 FA21                 5H604 AA08 BB01 BB14 CC01 CC02                       CC05 CC13 DB02 PB04 PC03                       QB14 QB15                 5H615 AA01 BB01 BB14 PP01 PP02                       PP08 PP13 PP14 QQ02 QQ12                       RR05 SS16 SS24 SS34 SS35                       TT03 TT31

Claims (5)

[Claims] 1. A welding point of a segment coil provided in a predetermined number in a radial direction in a plurality of rows in a circumferential direction of a stator or a rotor, and a thermosetting resin is melted and adhered to the welded portion to form an insulating film. A method of connecting segment coils to be formed, wherein a welding torch moves relative to the stator or rotor, and a welding step of sequentially welding the welded points, and a residual heat temperature due to welding of the welded portion, Within a period in which the thermosetting resin can be melted and attached at a temperature equal to or higher than a predetermined temperature according to the melting point of the thermosetting resin, a melt attaching step of attaching the thermosetting resin, and heat treatment of the attached thermosetting resin to form an insulating film. And a thermosetting step of forming the segment coil. 2. The method for connecting segment coils according to claim 1, wherein the predetermined temperature is 100 ° C. or higher and 180 ° C. or lower. 3. The method for connecting segment coils according to claim 1, wherein the melt adhesion period is within 3 minutes from the start of the welding. 4. An insulating film is formed by welding the welded points of a segment coil provided in a plurality of rows in the circumferential direction of the stator or rotor and provided in a predetermined number in the radial direction, and thermosetting resin is melted and adhered to the welded portions. A method for connecting segment coils, wherein a welding torch moves in the radial direction of the stator or rotor, and a predetermined number of the points to be welded in the radial direction are sequentially welded by one row in a radial row welding. A step, a radial row melt adhesion step of melting and adhering the thermosetting resin to the radial welding row portion, and a thermosetting step of heat treating the adhered thermosetting resin to form an insulating film. And a segment coil connecting method. 5. A welded point of a segment coil provided in a plurality of rows in the circumferential direction of a stator or a rotor and provided in a predetermined number in the radial direction is welded, and a thermosetting resin is melted and adhered to the welded portion to form an insulating film. A method for connecting segment coils to form, comprising: a welding step in which a welding torch moves relative to the stator or rotor and sequentially welding the welded points; and the thermosetting resin in the welded portion. A method of connecting segment coils, comprising: an injection melting and adhering step of sequentially injecting the thermosetting resin, and a thermosetting step of heat-treating the adhered thermosetting resin to form an insulating film.