Method for manufacturing a stator and welding apparatus

Abstract

To provide a manufacturing method of stator capable of solving a conventional problem that the volume of the stator could not be reduced satisfactorily.SOLUTION: A disclosed manufacturing method of a stator includes: a weld end holding step of holding a coil end T11, which is one end of the wiring constituting the coil and another wiring T21 different from the coil with welding clamps 31 and 32; an electrode end holding step of holding a conductive position 22 provided in the other wiring with a pair of electrode clamps that have conductivity; and a welding step of joining the coil end T11 and the other wiring T21 clamped by the welding clamps 31 and 32 by energizing the electrode clamp 33 by TIG welding.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a stator and a welding apparatus, and more particularly to a method for manufacturing a stator in which ends of segment coils provided in the stator are joined by TIG welding, and a welding apparatus for performing the TIG welding.

Background Art

[0002] In recent years, the demand for electric vehicles (hybrid vehicles, plug-in hybrid vehicles, electric vehicles, etc.) that use a motor as a driving power source has been expanding. For such motors mounted on electric vehicles, a stator (stator) and a rotor (rotor) are used. A large number of segment coils are used in the stator. Here, if the number of driving phases of the motor is 3, the segment coil is divided so as to form three current paths. And the divided segment coils are each composed of a plurality of segment coils for each current path. At this time, a plurality of segment coils constituting one current path are electrically connected by TIG (Tungsten Inert Gas) welding of the coil ends. Therefore, a TIG welding technique for segment coils is disclosed in Patent Document 1.

[0003] The method for manufacturing a stator described in Patent Document 1 includes a stator core that is annular, has a main surface perpendicular to its axial direction, and is formed with a plurality of slots that penetrate in the axial direction and extend in the radial direction arranged side by side in the circumferential direction, and a plurality of segment members inserted into the slots. Each segment end projects from the main surface, and a pair of the segment ends adjacent to each other and welded to each other form a segment end pair. A plurality of these segment end pairs are arranged in a row in the radial direction to form a segment end pair group, and a plurality of these segment end pair groups are arranged side by side in the circumferential direction. Among the segment-inserted stator cores, it is a method for manufacturing a stator that positions each of the segment end pairs. It has a first end pair group insertion window that extends in the radial direction corresponding to each of the segment end pair groups and is formed with a plurality of them arranged side by side in the circumferential direction. The first inner peripheral wall constituting the first end pair group insertion window has a first plate having a plurality of first protrusions that project toward one first circumferential direction in the circumferential direction and are arranged side by side at a predetermined interval in the radial direction. The first plate is arranged on the main surface side of the stator core. The segment end pair group is inserted into the first end pair group insertion window, and the tip side of each of the segment ends is projected from the first plate. It has a second end pair group insertion window that extends in the radial direction corresponding to each of the segment end pair groups and is formed with a plurality of them arranged side by side in the circumferential direction. The second inner peripheral wall constituting the second end pair group insertion window has a second plate having a plurality of second protrusions that project toward a second circumferential direction opposite to the first circumferential direction in the circumferential direction and are arranged side by side at a predetermined interval in the radial direction. The second plate is arranged on the first plate and on the side opposite to the stator core. The segment end pair group is inserted into the second end pair group insertion window, and at least each welding tip end to be welded among the segment ends is projected from the second plate. The first plate is rotated in the first circumferential direction and the secondRotate the plate in the second circumferential direction to move the first protrusion in the first circumferential direction, insert it between the pairs of segment ends that make up the group of segment ends, move the second protrusion in the second circumferential direction, and insert it between the pairs of segment ends that make up the group of segment ends to position each pair of segment ends.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the method for manufacturing a stator described in Patent Document 1, the length of the coil end had to be increased in order to bring an electrode for TIG welding into contact with the coil end to be welded, and there was a problem that it was difficult to miniaturize the stator.

[0006] The present invention has been made to solve such problems, and an object thereof is to reduce the volume of a stator including a coil.

Means for Solving the Problems

[0007] One aspect of the method for manufacturing a stator according to the present invention is a method for manufacturing a stator that performs TIG (Tungsten Inert Gas) welding on the ends of a plurality of coils arranged side by side in the circumferential direction of an annular stator core, a welding end holding step of holding a coil end, which is one end of the wiring constituting the coil, and another wiring different from the coil with a welding clamp; an electrode end holding step of holding an energization position provided on the other wiring with an electrode clamp having conductivity; A welding step of energizing the electrode clamp to join the coil end clamped by the welding clamp and the other wiring by TIG welding; It has.

[0008] One aspect of the welding apparatus according to the present invention is a welding apparatus that performs TIG (Tungsten Inert Gas) welding on a plurality of coils arranged side by side in the circumferential direction of an annular stator core, and includes a coil end that is one end of the wiring constituting the coil, and a welding clamp control unit that holds the coil end and another wiring different from the coil with a welding clamp, an electrode clamp control unit that holds the energization position provided on the other wiring with an electrode clamp having conductivity, and a torch control unit that controls a torch for joining the coil end and the other wiring by TIG welding; It has.

[0009] In the method for manufacturing a stator and the welding apparatus according to the present invention, by performing TIG welding in a state where an electrode clamp is brought into contact with a position different from the coil end to be welded, the length of the coil end to be welded is shortened.

Effect of the Invention

[0010] According to the present invention, the volume of a stator including coils can be reduced.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0012] For the sake of clarity of explanation, the following descriptions and drawings are appropriately omitted and simplified. Also, in each drawing, the same reference numerals are assigned to the same elements, and redundant explanations are omitted as necessary.

[0013] Embodiment 1 The method for manufacturing a stator according to Embodiment 1 performs TIG (Tungsten Inert Gas) welding on a plurality of coils arranged side by side in the circumferential direction of an annular stator core. And the method for manufacturing a stator according to Embodiment 1 has one of the characteristics in the clamping method of the end portion of the coil during welding (hereinafter referred to as the coil end). Therefore, FIG. 1 shows a diagram for explaining the clamping position in the method for manufacturing a stator according to Embodiment 1.

[0014] Note that the coils provided in the stator include a segment coil formed in a U shape and a cassette coil formed in a spring shape. The segment coil is used for a distributed winding stator, and the cassette coil is used for a concentrated winding stator. In the following description, a method for manufacturing a stator having a cassette coil and a welding apparatus for performing TIG welding on this stator will be described, but TIG welding can also be similarly performed on the segment coil.

[0015] Also, in the following description, an example of welding the first coil end that is the end of the first cassette coil and the second coil end that is the end of the second cassette coil will be described. That is, in the following description, the other wiring is the second coil end that is the end of the second cassette coil. However, the wiring to be welded at the first coil end is not limited to only the second coil end, and various wirings such as bus bars and power lines can be welding targets.

[0016] First, the method for manufacturing a stator according to Embodiment 1 includes at least a welding end holding step, an electrode end holding step, and a welding step. In the welding end holding step, a coil end, which is one end of the wiring forming the coil, and another wiring different from the coil are held by a welding clamp. The electrode end holding step holds the energization position provided on the other wiring with an electrode clamp having conductivity. In the welding step, the electrode clamp is energized to join the coil end clamped by the welding clamp and the other wiring by TIG welding.

[0017] Here, when two cassette coils are taken as an example, the coil end becomes the first coil end, the other wiring becomes the second coil end, and the energization position becomes the third coil end. Therefore, when specifically rephrasing the method for manufacturing a stator according to Embodiment 1 using these coil ends, it is as follows. In the welding end holding step, the first coil end, which is one end of the wiring forming the first cassette coil, and the second coil end, which is the other end of the wiring forming the second cassette coil adjacent to the first cassette coil with one or more cassette coils sandwiched therebetween, are held by a welding clamp. In the electrode end holding step, the third coil end, which is the end on the opposite side of the second coil end of the second cassette coil, is held by an electrode clamp having conductivity. In the welding step, the electrode clamp is energized to join the first coil end and the second coil end by TIG welding with the welding clamp.

[0018] In the following description, an example will be described in which the cassette coil 11 is the first cassette coil and the cassette coil 12 is the second cassette coil. However, the first cassette coil and the second cassette coil indicate the relationship between two cassette coils having wiring to be welded, and either of the two cassette coils may be the first cassette coil and the second cassette coil.

[0019] In addition, the method for manufacturing a stator according to Embodiment 1 is applicable regardless of the number of driving phases of the motor. However, in the following description, a method for manufacturing a stator applied to a three-phase driving motor will be described.

[0020] In the example shown in FIG. 1, two cassette coils to which coil wires are welded out of a plurality of cassette coils corresponding to a predetermined single phase are shown in the stator core 10. More specifically, in FIG. 1, the first cassette coil (for example, cassette coil 11) and the second cassette coil (for example, cassette coil 12) among the cassette coils mounted on the stator core 10 are shown. Further, since the example shown in FIG. 1 is a three-phase driving motor, cassette coils of the same phase are arranged in the circumferential direction of the stator core 10 every three.

[0021] As shown in FIG. 1, the cassette coil 11 has a first coil end (for example, coil end T11) protruding from the cassette coil 11 and a coil end T12 extending toward a cassette coil of the same phase adjacent to the cassette coil 11 on the side opposite to the cassette coil 12. Further, the cassette coil 12 has a coil end T21 extending from the cassette coil 11 side to the position of the coil end T11 of the cassette coil 11, and a third coil end (for example, coil end T22) protruding from the cassette coil 11 at an end opposite to the coil end T21.

[0022] Then, in the method for manufacturing a stator according to Embodiment 1, two coil ends at a welding target position where the coil ends of different cassette coils are close to each other are clamped by welding clamps 31 and 32. In TIG welding, it is necessary to bring an electrode serving as a current path into contact with the base material to be welded. In the method for manufacturing a stator according to Embodiment 1, a coil end of one of the two cassette coils to be welded is held at a position different from the welding target position by an electrically conductive electrode clamp. In the example shown in FIG. 1, the coil end T2 2 (for example, the third coil end) of the cassette coil 12 is held by the electrode clamp 33. Note that the coil end held by the electrode clamp 33 may be the coil end T12 of the cassette coil 12.

[0023] Next, the welding position, which is the position for clamping the coil ends T11 and T21 to be welded, and the electrode position for clamping the coil end T22 with the electrode clamp, which are set in the method for manufacturing the stator according to Embodiment 1, will be described. Therefore, FIG. 2 shows a view of the clamping positions in the method for manufacturing the stator according to Embodiment 1 as seen from the upper surface of the stator.

[0024] In the method for manufacturing the stator according to Embodiment 1, a welding apparatus 1 described later is used. As shown in FIG. 2, the welding apparatus 1 rotates the stator to sequentially move the coil ends T11 and T21 arranged in the circumferential direction of the stator core 10 to the welding position A, which is the movable range of the welding clamps 31 and 32. Further, in the welding apparatus 1, the stator is rotated to sequentially move the coil end T12 arranged in the circumferential direction of the stator core 10 to the electrode position B, which is the movable range of the electrode clamp 33.

[0025] Note that in the method for manufacturing the stator according to Embodiment 1, the stator core 10 may be fixed and the welding clamps 31 and 32 and the electrode clamp 33 may be moved in accordance with the positions of the coil ends arranged in the circumferential direction of the stator core 10.

[0026] Next, the form of the welding clamp for holding the coil ends T11 and T21 to be welded will be described. Therefore, FIG. 3 shows a view for explaining the first example of the welding clamp in the method for manufacturing the stator according to Embodiment 1, and FIG. 4 shows a view for explaining the second example of the welding clamp in the method for manufacturing the stator according to Embodiment 1. Note that in order to show the shape of the clamp jig, FIG. 3 shows a perspective view of the clamp jig, and FIG. 4 shows a top view and a side view of the clamp jig.

[0027] The first example shown in FIG. 3 illustrates the welding clamps 31 and 32 when the directions in which the ends of the coil ends T11 and T21 face are the same direction. Also, the second example shown in FIG. 4 illustrates the welding clamps 31 and 32 when the directions in which the ends of the coil ends T11 and T21 face intersect. As shown in FIGS. 3 and 4, the coil ends T11 and T21 to be welded are clamped in a state where the insulating coatings IC1 and IC2 for preventing conduction between the wirings are peeled off. The welding clamps 31 and 32 hold the coil ends T11 and T21 such that the portions where the insulating coatings IC1 and IC2 are peeled off come into contact. Also, as shown in FIGS. 3 and 4, in the method for manufacturing a stator according to Embodiment 1, the electrode clamp is at an electrode position B different from the welding position A. Therefore, in the welding apparatus 1 according to Embodiment 1, the length of the metal portion where the insulating coatings IC1 and IC2 are peeled off and which becomes the current path can be suppressed to the minimum necessary length as the welding portion. That is, in the method for manufacturing a stator according to Embodiment 1, the length of contact with the electrode clamp is not required when determining the length of exposing the metal. From such a fact, in the method for manufacturing a stator according to Embodiment 1, it becomes possible to reduce the metal exposure range of the welding target portion and reduce the volume of the stator.

[0028] Also, in the first example shown in FIG. 3, the coil ends T11 and T21 are clamped so as to come into contact with each other using the welding clamp 31 and the welding clamp 32 from both sides in a direction orthogonal to the direction in which the coil ends T11 and T21 face each other. For example, the welding clamps 31 and 32 have tapered surfaces on the side faces, and are configured such that the coil ends T11 and T 21 approach each other as the welding clamps 31 and 32 approach. That is, the clamping jig shown in FIG. 3 includes a first clamping jig 31 that fixes the positions of the first coil end T11 and the second coil end T 21 and a second clamping jig 32 that fixes the positions of the first coil end T11 and the second coil end T21 from a direction opposite to the first clamping jig 31.

[0029] Also, in the second example shown in FIG. 4, the clamping jig has a first clamping jig (e.g., welding clamp 31) that presses the first coil end T11 toward the second coil end T21 side, and a second clamping jig (e.g., welding clamp 32) that presses the second coil end T21 toward the first coil end T11 side. As shown in FIG. 4, in the method for manufacturing a stator according to Embodiment 1, since the clamping jigs that become the welding clamps 31 and 32 do not need to be energized, it is also possible to hold down the insulating film portion of the coil end portion.

[0030] Here, the characteristics of the clamps used for TIG welding will be described. First, the welding clamps 31 and 32 are required to have high material strength or a shape capable of maintaining strength in order to generate a pressing force that brings the two coil end portions to be welded into contact during clamping. Also, the electrode clamp 33 is required to have high electrical conductivity, but since it only needs to be able to contact the uncoated metal wiring, it is not required to have strength to withstand the clamping load.

[0031] Here, for example, unlike the method for manufacturing a stator according to Embodiment 1, if an attempt is made to realize the functions of the electrode clamp and the welding clamp with a single clamping jig, significant restrictions are imposed on the material selection and the shape of the clamping jig. However, in the method for manufacturing a stator according to Embodiment 1, the welding clamp is only required to have the function of repeatedly holding the coil end T11 and the coil end T21 to be welded, and the electrode clamp can be required to have only conductivity. Therefore, in the method for manufacturing a stator according to Embodiment 1, there is a degree of freedom to appropriately design the shapes and characteristics of the welding clamp and the electrode clamp according to the required performance for each. As a result, in the method for manufacturing a stator according to Embodiment 1, it is possible to reduce the volume of the clamping jig and improve the durability.

[0032] Here, the flow of the method for manufacturing a stator according to Embodiment 1 will be described. Therefore, FIG. 5 shows a flowchart for explaining the flow of the method for manufacturing a stator according to Embodiment 1.

[0033] As shown in FIG. 5, in the method for manufacturing a stator according to Embodiment 1, first, welding target ends (for example, coil ends T11, T21) are clamped by welding clamps 31 and 32 (step S1). Next, for one of the two cassette coils to be welded (for example, cassette coil 12), the end opposite to the welding target end (coil end T21) (for example, coil end T22) is clamped by an electrode clamp 33 (step S2).

[0034] Subsequently, in the welding apparatus 1 according to Embodiment 1, the electrode clamp 33 is energized to perform TIG welding on the coil ends T11 and T21 clamped by the welding clamps 31 and 32 (step S3). Then, when the TIG welding is completed, the welding clamps 31 and 32 and the electrode clamp 33 are released to separate the clamping jig from the coil ends and release the coil ends (step S4).

[0035] Subsequently, in Embodiment 1, after step S4, the stator is rotated to move the adjacent welding target ends to the welding position A (step S5). Note that in step S5, the coil end clamped by the electrode clamp 33 also becomes the third coil end of the adjacent cassette coil. Then, after rotating the stator, the coil ends located at the welding position A are observed with, for example, a camera or the like. If the welding target ends have already been welded, the welding process is completed. If not, the newly arrived coil ends at the welding position A are welded according to steps S1 to S5 (step S6).

[0036] Here, the welding apparatus used in the method for manufacturing a stator according to Embodiment 1 will be described. Therefore, FIG. 6 shows a block diagram for explaining the outline of the welding apparatus 1 according to Embodiment 1. The block diagram shown in FIG. 6 is a functional block diagram of the welding apparatus 1, and the actual shape of the apparatus varies depending on the situation of the factory facilities and the like.

[0037] As shown in FIG. 6, the welding apparatus 1 includes an apparatus control unit 41, a welding clamp control unit 42, an electrode clamp control unit 43, a torch control unit 44, a stator rotation control unit 46, welding clamps 31 and 32, an electrode clamp 33, and a torch 45. Although not shown in FIG. 6, the welding apparatus 1 uses various sensors such as a camera to check the welding status of the stator and the positions of the welding clamps 31 and 32 and the torch 45.

[0038] The apparatus control unit 41 gives operation instructions to the welding clamp control unit 42, the electrode clamp control unit 43, the torch control unit 44, and the stator rotation control unit 46 according to the flowchart shown in FIG. 5. Further, the apparatus control unit 41 determines whether the welding target end at the welding position A has been welded using a sensor such as a camera. That is, the process of step S6 in FIG. 5 is performed by the apparatus control unit 41.

[0039] The welding clamp control unit 42 holds a coil end, which is one end of the wiring forming the coil, and another wiring different from the coil with welding clamps. More specifically, the welding clamp control unit 42 controls the welding clamps 31 and 32 to hold a first coil end (for example, coil end T11), which is one end of the wiring forming the first cassette coil (for example, cassette coil 11), and a second coil end (for example, coil end T21), which is the other end of the wiring forming a second cassette coil (for example, cassette coil 12) adjacent to the cassette coil 11 with one or more cassette coils interposed therebetween. That is, the welding clamp control unit 42 performs the processes of steps S1 and S4 in FIG. 5.

[0040] The electrode clamp control unit 43 holds the energization position provided on the other wiring with a conductive electrode clamp. More specifically, the electrode clamp control unit 43 controls the electrode clamp 33 to hold a third coil end (for example, coil end T22), which is the end on the opposite side of the coil end T21 of the cassette coil 12, with the conductive electrode clamp 33. That is, the electrode clamp control unit 43 performs the processes of steps S2 and S4 in FIG. 5.

[0041] The torch control unit 44 controls the torch that joins the coil end and other wiring by TIG welding. More specifically, the torch control unit 44 controls the position and discharge state of the torch that generates an arc between the base material to be welded (the metal exposed at the coil ends T11 and T21). The torch control unit 44 also controls the discharge state of the torch that is ejected from the torch 45 near the welding point. inactive The torch control unit 44 controls the ejection state of the gas (for example, argon gas). of 3 The process of energizing the electrode clamp 33 in step S3 is performed by the electrode clamp control unit 43.

[0042] The stator rotation control unit 46 controls the coil end to be welded. of the stator The next coil end adjacent in the opposite direction to the direction of rotation is moved to the position of the coil end before the rotation. More specifically, the stator rotation control unit 46 rotates the stator core 10 after the welding process (step S4 in FIG. 5), and moves the third cassette coil and the fourth cassette coil adjacent in the opposite direction to the direction of rotation of the cassette coils 11 and 12 to the positions of the cassette coils 11 and 12 before the rotation. In other words, the stator rotation control unit 46 performs the process of step S5 in FIG. 5.

[0043] Although welding device 1 is configured to rotate stator core 10, it is also possible to fix stator core 10 and move welding clamps 31, 32, electrode clamp 33, and torch 45. However, rotating stator core 10 allows the range of movement of welding clamps 31, 32, electrode clamp 33, and torch 45 to be narrowed, and therefore the volume of the device related to welding clamps 31, 32, electrode clamp 33, and torch 45 can be reduced.

[0044] From the above description, in the method for manufacturing a stator according to Embodiment 1, the electrode clamp 33 is brought into contact with the cassette coil at a position away from the welding clamps 31 and 32 that require a high pressing force. Thereby, in the method for manufacturing a stator according to Embodiment 1, the area of the coated and peeled portion of the coil end to be welded is reduced to suppress the length of the coil end. And since the length of the coil end is suppressed, the volume of the stator completed using the method for manufacturing a stator according to Embodiment 1 becomes small.

[0045] Also, by setting the positions where the welding clamps 31 and 32 clamp and the position where the electrode clamp 33 clamps at positions away from each other, in the method for manufacturing a stator according to Embodiment 1, the welding clamps and the electrode clamp can be freely designed according to the characteristics required for the welding portion and the electrode contact portion. Thereby, by using the method for manufacturing a stator according to Embodiment 1, it is possible to improve the durability of each clamp and reduce the volume.

[0046] Also, in the welding apparatus 1 according to Embodiment 1, the switching of the welding portion is performed by rotating the stator core 10. Thereby, in the welding apparatus 1 according to Embodiment 1, it is possible to achieve miniaturization of the apparatus and high durability by reducing the movable parts.

[0047] As described above, the invention made by the present inventor has been specifically described based on the embodiments. However, it goes without saying that the present invention is not limited to the embodiments already described, and various modifications are possible without departing from the gist thereof.

Description of Reference Numerals

[0048] 1 Welding apparatus 10 Stator core 11 Cassette coil 12 Cassette coil 31 Welding clamp 32 Welding clamp 33 Electrode clamp 41 Apparatus control unit 42 Welding clamp control unit 43 Electrode Clamp Control Unit 44 Torch Control Unit 45 Torch 46 Stator Rotation Control Unit A Welding Position B Electrode Position T11 Coil End T12 Coil End T21 Coil End T22 Coil End

Claims

1. A method for manufacturing a stator that performs TIG (Tungsten Inert Gas) welding on the ends of a plurality of coils arranged side by side in the circumferential direction of an annular stator core, comprising: a welding end holding step of holding a coil end, which is one end of the wiring constituting the coil, and another wiring different from the coil, with a welding clamp; an electrode end holding step of holding an energization position different from the welding target position provided on the other wiring with an electrode clamp having conductivity; a welding step of energizing the electrode clamp and joining the coil end clamped by the welding clamp and the other wiring by TIG welding; A method for manufacturing a stator having the above steps.

2. The method for manufacturing a stator according to claim 1, further comprising a next welding preparation step of rotating the stator core after the welding step and moving a next coil end adjacent to the coil end to be welded in a direction opposite to the rotation direction to the position of the coil end before the rotation.

3. The method for manufacturing a stator according to claim 1, wherein the welding clamp performs the welding end holding step with a first clamp jig that presses the coil end against the other wiring side and a second clamp jig that presses the other wiring against the coil end side.

4. The method for manufacturing a stator according to claim 1, wherein the welding clamp performs the welding end holding step with a first clamp jig that fixes the positions of the coil end and the other wiring and a second clamp jig that fixes the positions of the coil end and the other wiring from a direction opposite to the first clamp jig.

5. A welding apparatus for performing TIG (Tungsten Inert Gas) welding on a plurality of coils arranged side by side in the circumferential direction of an annular stator core, comprising: a welding clamp control unit that holds a coil end, which is one end of the wiring constituting the coil, and another wiring different from the coil, with a welding clamp; an electrode clamp control unit that holds an energization position different from the welding target position provided on the other wiring with an electrode clamp having conductivity; a torch control unit that controls a torch for joining the coil end and the other wiring by TIG welding; A welding apparatus having the above components.

6. The welding apparatus according to claim 5, further comprising a stator rotation control unit that rotates the stator core and moves the next coil end adjacent to the coil end to be welded in a direction opposite to the rotation direction to the position of the coil end before the rotation.

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