Method for manufacturing a stator and welding device

Abstract

Provided is a method for manufacturing a stator capable of reducing the volume of the stator including a coil, and a welding device. In a conventional method for manufacturing a stator, there is a problem that the volume of the stator cannot be sufficiently reduced. The method for manufacturing a stator of the present invention includes a welding end holding step of holding, by a welding clamp, one end of a wire constituting a coil, i.e., a coil end, and another wire different from the coil, an electrode end holding step of holding, by an electrode clamp having conductivity, an energization position provided to the other wire, and a welding step of energizing the electrode clamp and joining the coil end held by the welding clamp and the other wire by TIG welding.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a stator and a welding apparatus, and particularly to a method for manufacturing a stator by joining the ends of segmented coils of a stator by TIG welding and a welding apparatus for performing the TIG welding. Background Technology

[0002] In recent years, the demand for electric vehicles (hybrid electric vehicles, plug-in hybrid electric vehicles, battery electric vehicles, etc.) that use electric motors as a driving force has increased. The electric motors used in such electric vehicles employ a stator (fixed component) and a rotor (rotating component). Furthermore, the stator uses multiple segmented coils. Here, if the number of driving phases of the electric motor is 3, the segmented coils are divided to form 3 current paths. Moreover, the divided segmented coils are composed of multiple segmented coils for each current path. In this case, the multiple segmented coils forming one current path are electrically connected by TIG (Tungsten Inert Gas) welding of the coil ends. Therefore, Japanese Patent Application Publication No. 2005-130577 discloses a TIG welding technology for segmented coils.

[0003] The stator manufacturing method described in Japanese Patent Application Publication No. 2005-130577 is a method for manufacturing a stator having a stator core and segmented members inserted into the stator core in a segmented manner, and for positioning the end pairs of the segments respectively. The stator core is annular and has a main surface perpendicular to its axial direction. Multiple slots are arranged circumferentially, extending radially and penetrating the axial direction. The segmented members are multiple segmented members inserted into the slots. Each segment end protrudes from the main surface, and a pair of adjacent and welded segment ends constitutes a segment end pair. Multiple segmented end pairs are arranged in a row in the radial direction to form segmented end pairs. Multiple segmented end pairs are arranged in a circumferential direction. The stator manufacturing method includes a positioning step in which a first plate is positioned on the main face side of the stator core, the segmented end pairs are inserted into a first end pair insertion window such that the top ends of each segmented end protrude from the first plate, a second plate is positioned on the first plate on the side opposite to the stator core, and the segmented end pairs are inserted into a second end pair insertion window such that at least one of the segmented ends is welded. Each welded end portion protrudes from the second plate, causing the first plate to rotate in a first circumferential direction and the second plate to rotate in a second circumferential direction, causing the first protrusion to move in the first circumferential direction and be inserted into the segmented end pairs constituting the segmented end pairs respectively, and causing the second protrusion to move in the second circumferential direction and be inserted into the segmented end pairs constituting the segmented end pairs respectively, thereby positioning the segmented end pairs respectively. The first plate has a plurality of first end pair insertion windows that extend radially and are arranged circumferentially in accordance with each segmented end pair, and the first inner peripheral wall constituting the first end pair insertion window has a first circumferential protrusion toward one of the circumferential directions and a plurality of first protrusions arranged at predetermined intervals in the radial direction. The second plate has a plurality of second end pair insertion windows that extend radially and are arranged circumferentially in accordance with each segmented end pair, and the second inner peripheral wall constituting the second end pair insertion window has a second circumferential protrusion toward the side of the circumferential direction opposite to the first circumferential direction and a plurality of second protrusions arranged at predetermined intervals in the radial direction. Summary of the Invention

[0004] However, in the stator manufacturing method described in Japanese Patent Application Publication No. 2005-130577, in order to make the electrode used for TIG welding contact with the end of the coil of the object being welded, the length of the coil end must be increased, which presents a problem of difficulty in miniaturizing the stator.

[0005] This invention was made to solve such a problem, and its purpose is to reduce the volume of the stator, including the coils.

[0006] One aspect of the stator manufacturing method of the present invention is a method for manufacturing a stator by performing TIG (Tungsten Inert Gas) welding on the ends of a plurality of coils arranged circumferentially on an annular stator core, comprising:

[0007] The welding end holding process uses welding clamps to hold one end of the wiring that constitutes the coil, namely the coil end, and other wiring that is different from the coil.

[0008] The electrode holding process utilizes conductive electrode clamps to hold the electrode in a energized position relative to the other wiring; and

[0009] The welding process involves energizing the electrode clamping member and using TIG welding to connect the coil end, which is clamped by the welding clamping member, to the other wiring.

[0010] One embodiment of the welding apparatus of the present invention is a welding apparatus for performing TIG (Tungsten Inert Gas) welding on a plurality of coils arranged circumferentially on a ring-shaped stator core, comprising: a welding clamp control unit that holds one end of the wiring constituting the coil, i.e., the coil end, and other wirings different from the coil using welding clamps; an electrode clamp control unit that holds the other wirings in an energized position using conductive electrode clamps; and a welding torch control unit that controls the welding torch that joins the coil end to the other wirings by TIG welding.

[0011] In the stator manufacturing method and welding apparatus of the present invention, the length of the coil end of the object to be welded is shortened by performing TIG welding with the electrode clamping member in contact with a position other than the coil end of the object to be welded.

[0012] According to the present invention, the volume of the stator, including the coils, can be reduced.

[0013] The foregoing and other objects, features and advantages of this disclosure will become more fully understood from the following detailed description and the accompanying drawings, which are given by way of illustration only, and are therefore not to be construed as limiting the disclosure. Attached Figure Description

[0014] Figure 1 This is a diagram illustrating the clamping position in the stator manufacturing method of Embodiment 1.

[0015] Figure 2 This is a diagram showing the clamping position in the stator manufacturing method of Embodiment 1, viewed from the upper surface of the stator.

[0016] Figure 3 This is a diagram illustrating the first example of a welding clamping member in the stator manufacturing method of Embodiment 1.

[0017] Figure 4 This is a second example of a welding clamping member used in the stator manufacturing method of Embodiment 1.

[0018] Figure 5 This is a flowchart illustrating the manufacturing method of the stator according to Embodiment 1.

[0019] Figure 6 This is a schematic block diagram illustrating the welding apparatus of Embodiment 1. Detailed Implementation

[0020] For clarity, the following descriptions and figures are appropriately omitted and simplified. Furthermore, in each figure, the same reference numerals are used for the same elements, and repeated descriptions are omitted where necessary.

[0021] Implementation Method 1

[0022] The stator manufacturing method of Embodiment 1 involves TIG (Tungsten Inert Gas) welding of multiple coils arranged circumferentially on a ring-shaped stator core. Furthermore, the stator manufacturing method of Embodiment 1 has a characteristic feature in the clamping method of the coil ends (hereinafter referred to as coil ends) during welding. Therefore, Figure 1 This diagram illustrates the clamping position in the stator manufacturing method of Embodiment 1.

[0023] It should be noted that the coils provided in the stator include segmented coils formed in a U-shape and box-type coils formed in a spring shape. Segmented coils are used for distributed winding of the stator, while box-type coils are used for concentrated winding of the stator. In the following description, the manufacturing method of the stator with box-type coils and the welding apparatus for TIG welding of the stator are described, but TIG welding can also be performed on segmented coils in the same way.

[0024] Furthermore, in the following description, an example of welding the first coil end, which will be the end of the first box-type coil, and the second coil end, which will be the end of the second box-type coil, will be explained. That is, in the following description, the other wiring is the second coil end, which is the end of the second box-type coil. However, the wiring to be welded to the first coil end is not limited to the second coil end; various wiring such as busbars and power lines can also be used as the welding targets.

[0025] First, the stator manufacturing method of Embodiment 1 includes at least a welding end holding process, an electrode end holding process, and a welding process. In the welding end holding process, a welding clamp is used to hold one end of the wiring constituting the coil (i.e., the coil end) and other wirings different from the coil. In the electrode end holding process, a conductive electrode clamp is used to hold the energized position of the other wirings. In the welding process, the electrode clamp is energized, and the coil end clamped by the welding clamp is joined to the other wirings by TIG welding.

[0026] Here, taking two box-type coils as an example, the coil end is called the first coil end, the other wiring is called the second coil end, and the energized position is called the third coil end. Therefore, when specifically describing the stator manufacturing method of Embodiment 1 using these coil ends, the specific steps are as follows: In the welding end holding process, a welding clamp is used to hold one end of the wiring constituting the first box-type coil, i.e., the first coil end, and the other end of the wiring constituting the second box-type coil, which is adjacent to the first box-type coil and separated by one or more box-type coils, i.e., the second coil end. In the electrode end holding process, a conductive electrode clamp is used to hold the end opposite to the second coil end of the second box-type coil, i.e., the third coil end. In the welding process, the electrode clamp is energized, and the first coil end and the second coil end are joined by TIG welding.

[0027] In the following description, an example is given in which the box coil 11 is designated as the first box coil and the box coil 12 is designated as the second box coil. However, the first box coil and the second box coil represent the relationship between two box coils with wiring that is to be soldered. Either of the two box coils can also be designated as the first box coil and the second box coil.

[0028] Furthermore, the stator manufacturing method of Embodiment 1 can be applied regardless of the number of driving phases of the motor, but in the following description, the stator manufacturing method for a three-phase driven motor will be described.

[0029] exist Figure 1 The example shown depicts two box coils with coil wires from a plurality of box coils corresponding to a predetermined 1 soldered onto the stator core 10. More specifically, in Figure 1 The image shows a first box-shaped coil (e.g., box-shaped coil 11) and a second box-shaped coil (e.g., box-shaped coil 12) mounted in a box-shaped coil within the stator core 10. Additionally, Figure 1 The example shown is a three-phase drive motor, so the in-phase box coils are arranged circumferentially around the stator core 10 every three.

[0030] like Figure 1As shown, the box coil 11 has a first coil end (e.g., coil end T11) protruding from the box coil 11 and a coil end T12 extending toward the box coil of the same phase adjacent to the box coil 11 on the side opposite to the box coil 12. Additionally, the box coil 12 has: a coil end T21 extending toward the box coil 11 towards the coil end T11 of the box coil 11; and a third coil end (e.g., coil end T22), which is the end on the side opposite to the coil end T21 and protrudes from the box coil 11.

[0031] Furthermore, in the stator manufacturing method of Embodiment 1, welding clamps 31 and 32 are used to clamp the two coil ends located at welding target positions where the coil ends of different box coils are close to each other. Additionally, in TIG welding, it is necessary to ensure that the electrode, which serves as the current path, is in contact with the base material being welded. In the stator manufacturing method of Embodiment 1, conductive electrode clamps are used to hold the coil end of one of the two box coils being welded at a position different from the welding target position. Figure 1 In the example shown, the electrode clamp 33 holds the coil end T21 (e.g., the third coil end) of the box coil 12. It should be noted that the coil end held by the electrode clamp 33 can also be the coil end T12 of the box coil 12.

[0032] Next, the welding positions, specifically the positions for clamping the coil ends T11 and T21 (the objects to be welded), and the electrode positions for clamping the coil end T22 using electrode clamping members, will be explained in the stator manufacturing method of Embodiment 1. Therefore, Figure 2 A diagram showing the clamping position in the manufacturing method of the stator according to Embodiment 1, viewed from the upper surface of the stator.

[0033] In the stator manufacturing method of Embodiment 1, the welding apparatus 1 described later is used. Furthermore, as... Figure 2 As shown, the welding apparatus 1 rotates the stator, causing the coil ends T11 and T21, arranged circumferentially on the stator core 10, to move sequentially into the movable range of the welding clamps 31 and 32, i.e., welding position A. Additionally, in the welding apparatus 1, by rotating the stator, the coil end T12, arranged circumferentially on the stator core 10, moves sequentially into the movable range of the electrode clamp 33, i.e., electrode position B.

[0034] It should be noted that the stator manufacturing method of Embodiment 1 can also fix the stator core 10, so that the welding clamps 31, 32 and the electrode clamps 33 can move in a way that matches the position of the coil ends arranged in the circumferential direction of the stator core 10.

[0035] Next, an example of a welding clamp that holds the coil ends T11 and T21, which are the objects of welding, will be described. Therefore, Figure 3The figure shows a first example of a welding clamping component in the stator manufacturing method of Embodiment 1. Figure 4 This figure shows a second example of the welding clamping member in the stator manufacturing method of Embodiment 1. It should be noted that, in order to show the shape of the clamping fixture, [the following text is incomplete and requires further context: "in "] Figure 3 The image shows a perspective view of the clamping fixture. Figure 4 The diagram shows a top view of the clamping fixture and a side view of the clamping fixture.

[0036] Figure 3 The first example shown illustrates welding clamps 31 and 32 when the ends of coil end T11 and coil end T21 face the same direction. Additionally, Figure 4 The second example illustrates the welding clamps 31 and 32 when the directions of the ends of coil end T11 and coil end T21 intersect. For example... Figure 3 , Figure 4 As shown, coil ends T11 and T21, which are to be welded, are clamped with the insulating films IC1 and IC2, which are used to prevent the wiring from conducting to each other, peeled off. Welding clamps 31 and 32 hold coil ends T11 and T21 in contact with the peeled portions of the insulating films IC1 and IC2. Additionally, as... Figure 3 , Figure 4 As shown, in the stator manufacturing method of Embodiment 1, the electrode clamping member is located at electrode position B, which is different from the welding position A. Therefore, in the welding apparatus 1 of Embodiment 1, the length of the metal portion that becomes the current path after the insulating films IC1 and IC2 are peeled off can be suppressed to the minimum length required for the welding portion. In other words, in the stator manufacturing method of Embodiment 1, the length of contact between the electrode clamping member and the metal is not required when determining the length of the exposed metal. As a result, in the stator manufacturing method of Embodiment 1, the metal exposure range of the welding target area can be reduced, thereby reducing the volume of the stator.

[0037] In addition, Figure 3 In the first example shown, welding clamps 31 and 32 are used from both sides in a direction orthogonal to the direction facing coil ends T11 and T21, clamping the coil ends T11 and T21 in contact. For example, the welding clamps 31 and 32 can be configured to have tapered surfaces on their sides, and the closer the welding clamps 31 and 32 are, the closer the coil ends T11 and T21 are. That is, Figure 3 The clamping fixture shown has: a first clamping fixture 31, which fixes the positions of the first coil end T11 and the second coil end T21; and a second clamping fixture 32, which fixes the positions of the first coil end T11 and the second coil end T21 from the direction opposite to the first clamping fixture 31.

[0038] In addition, Figure 4 In the second example shown, the clamping fixture has a first clamping fixture (e.g., a welded clamping member 31) that presses the first coil end T11 against the second coil end T21, and a second clamping fixture (e.g., a welded clamping member 32) that presses the second coil end T21 against the first coil end T11. Figure 4 As shown, in the stator manufacturing method of Embodiment 1, the clamping fixtures that become welding clamping parts 31 and 32 do not need to be energized, so they can also press the insulating film portion in the coil end.

[0039] Here, the characteristics of the clamping components used for TIG welding will be explained. First, as welding clamping components 31 and 32, in order to generate a pressing pressure that brings the ends of the two coils to be welded into contact during clamping, it is required to maintain high material strength or a strong shape. In addition, for electrode clamping component 33, high current-carrying capacity is required, but on the other hand, it is sufficient to be able to contact the uncoated metal wiring, so strength to withstand clamping loads is not required.

[0040] Here, for example, unlike the stator manufacturing method of Embodiment 1, when it is desired to utilize a single clamping fixture to realize the functions of both an electrode clamping member and a welding clamping member, significant limitations are imposed on the selection of materials and the shape of the clamping fixture. However, in the stator manufacturing method of Embodiment 1, the welding clamping member is only required to repeatedly maintain the function of the coil ends T11 and T21, which are the objects of welding, and the electrode clamping member is only required to be conductive. Therefore, the stator manufacturing method of Embodiment 1 has the freedom to appropriately design the shape and characteristics of the welding clamping member and the electrode clamping member according to their respective required performance. As a result, in the stator manufacturing method of Embodiment 1, the size of the clamping fixture can be reduced and its durability improved.

[0041] Here, the process of manufacturing the stator according to Embodiment 1 will be described. Therefore, Figure 5 A flowchart illustrating the manufacturing method of the stator according to Embodiment 1.

[0042] like Figure 5 As shown, in the stator manufacturing method of Embodiment 1, the ends of the object to be welded (e.g., coil ends T11, T21) are first clamped using welding clamping members 31 and 32 (step S1). Next, for one of the two box coils that are to be welded (e.g., box coil 12), the opposite end (e.g., coil end T22) of the end to be welded (coil end T21) is clamped using electrode clamping member 33 (step S2).

[0043] Next, in the welding apparatus 1 of Embodiment 1, the electrode clamping member 33 is energized to perform TIG welding on the coil ends T11 and T21 clamped by the welding clamping members 31 and 32 (step S3). Furthermore, when the TIG welding is completed, the clamping fixture is released from the coil ends by opening the welding clamping members 31 and 32 and the electrode clamping member 33 (step S4).

[0044] Next, in Embodiment 1, after step S4, the stator is rotated, moving the adjacent end of the object to be welded towards welding position A (step S5). It should be noted that in step S5, the coil end clamped by the electrode clamping member 33 also becomes the third coil end of the adjacent box-type coil. Furthermore, after rotating the stator, the coil end located at welding position A is observed, for example, using a camera. If the end of the object to be welded has been completed, the welding process is completed; if welding is completed, the coil end that has newly arrived at welding position A is welded according to steps S1 to S5 (step S6).

[0045] Here, the welding apparatus used in the stator manufacturing method of Embodiment 1 will be described. Therefore, Figure 6 This is a schematic block diagram illustrating the welding apparatus 1 of Embodiment 1.

[0046] Figure 6 The block diagram shown is a functional block diagram of welding device 1. The actual shape of the device varies depending on the condition of the factory equipment, etc.

[0047] like Figure 6 As shown, the welding apparatus 1 includes an apparatus control unit 41, a welding clamping component control unit 42, an electrode clamping component control unit 43, a welding torch control unit 44, a stator rotation control unit 46, welding clamping components 31 and 32, an electrode clamping component 33, and a welding torch 45. It should be noted that... Figure 6 Although the illustrations are omitted, the welding device 1 uses various sensors such as cameras to confirm the welding status in the stator, the position of the welding clamps 31 and 32, and the welding torch 45.

[0048] Device control unit 41 according to Figure 5 The flowchart shown provides operation instructions to the welding clamp control unit 42, electrode clamp control unit 43, welding torch control unit 44, and stator rotation control unit 46. Additionally, the device control unit 41 uses sensors such as a camera to determine whether the end of the workpiece located at welding position A has been welded. In other words, Figure 5 The processing of step S6 is performed by the device control unit 41.

[0049] The welding clamping control unit 42 uses welding clamps to hold one end of the wiring constituting the coil, i.e., the coil end, and other wiring different from the coil. More specifically, the welding clamping control unit 42 controls the welding clamps 31 and 32 to hold one end of the wiring constituting the first box-type coil (e.g., box-type coil 11), i.e., the first coil end (e.g., coil end T11), and the other end of the wiring constituting the second box-type coil (e.g., box-type coil 12) adjacent to the box-type coil 11, separated by one or more box-type coils, i.e., the second coil end (e.g., coil end T21). That is, the welding clamping control unit 42 performs... Figure 5 The processing of steps S1 and S4.

[0050] The electrode clamping control unit 43 uses a conductive electrode clamping member to hold the electrode in a energized position relative to other wiring. More specifically, the electrode clamping control unit 43 controls the electrode clamping member 33 to hold the third coil end (e.g., coil end T22) opposite to the coil end T21 of the box-type coil 12 using the conductive electrode clamping member 33. That is, the electrode clamping control unit 43 performs... Figure 5 The processing of steps S2 and S4.

[0051] The torch control unit 44 controls the torch that joins the coil ends with other wiring via TIG welding. More specifically, the torch control unit 44 controls the position and discharge state of the torch that generates an arc between itself and the base material of the workpiece (the metal exposed at coil ends T11 and T21). Additionally, the torch control unit 44 controls the ejection state of inert gases (such as argon) emitted from the torch 45 towards the vicinity of the welding area. In other words, the torch control unit 44 performs… Figure 5 The processing in step S3. It should be noted that the energization of the electrode clamping member 33 in step S3 is performed by the electrode clamping member control unit 43.

[0052] The stator rotation control unit 46 moves the next coil end adjacent to the coil end to be welded in the opposite direction to the stator rotation direction back to the position of the coil end before rotation. More specifically, the stator rotation control unit 46 in the welding process ( Figure 5 After step S4), the stator core 10 is rotated, causing the adjacent third and fourth box coils in the opposite direction to the rotation direction of the box coils 11 and 12 to move back to their original positions before rotation. In other words, the stator rotation control unit 46 performs... Figure 5 The processing of step S5.

[0053] It should be noted that while the welding apparatus 1 is configured to rotate the stator core 10, there are also methods that fix the stator core 10 while moving the welding clamps 31, 32, electrode clamps 33, and welding torch 45. However, when the stator core 10 is rotated, the movable range of the welding clamps 31, 32, electrode clamps 33, and welding torch 45 can be set narrower, thus reducing the size of the devices associated with the welding clamps 31, 32, electrode clamps 33, and welding torch 45.

[0054] According to the above description, in the stator manufacturing method of Embodiment 1, the electrode clamping member 33 is brought into contact with the box-type coil at a position away from the welding clamping members 31 and 32 that require high pressing pressure. Therefore, in the stator manufacturing method of Embodiment 1, the area of ​​the coating stripped portion at the coil end to be welded is reduced, thereby suppressing the length of the coil end. Furthermore, by suppressing the length of the coil end, the volume of the stator completed using the stator manufacturing method of Embodiment 1 is reduced.

[0055] Furthermore, by setting the clamping positions of the welding clamping members 31 and 32 and the electrode clamping member 33 to be in separate positions, the stator manufacturing method of Embodiment 1 allows for the free design of the welding clamping members and electrode clamping members according to the characteristics required by the welding parts and electrode contact parts. Therefore, by using the stator manufacturing method of Embodiment 1, it is possible to improve the durability of each clamping member and reduce its size.

[0056] Furthermore, in the welding apparatus 1 of Embodiment 1, the welding position is switched by rotating the stator core 10. Therefore, in the welding apparatus 1 of Embodiment 1, miniaturization of the apparatus and high durability due to the reduction of movable parts can be achieved.

[0057] From this description of the present disclosure, it will be apparent that embodiments of the present disclosure can be modified in various ways. These modifications should not be considered a departure from the spirit and scope of the present disclosure, and it will be apparent to those skilled in the art that all such modifications are intended to be included within the scope of the claims.

Claims

1. A method for manufacturing a stator, wherein the method involves TIG welding the ends of a plurality of coils arranged circumferentially on an annular stator core, wherein... include: The welding end holding process uses welding clamps to hold one end of the wiring that constitutes the coil, namely the coil end, and other wiring that is different from the coil. The electrode holding process utilizes conductive electrode clamps to hold the energized position of the other wiring, which is different from the position of the object being welded; and The welding process involves energizing the electrode clamping member and using TIG welding to connect the coil end, which is clamped by the welding clamping member, to the other wiring.

2. The method for manufacturing a stator according to claim 1, wherein, The process includes a next welding preparation step, after which the stator core is rotated so that the next coil end adjacent to the coil end to be welded moves in the opposite direction to the direction of the rotation towards the position of the coil end before the rotation.

3. The method for manufacturing a stator according to claim 1, wherein, The welding clamping device performs the welding end holding process by using a first clamping fixture that presses the coil end against the other wiring side and a second clamping fixture that presses the other wiring against the coil end side.

4. The method for manufacturing a stator according to claim 1, wherein, The welding clamping component uses a first clamping fixture and a second clamping fixture to perform the welding end holding process. The first clamping fixture fixes the position of the coil end and the other wiring, and the second clamping fixture fixes the position of the coil end and the other wiring from a direction opposite to the first clamping fixture.

5. A welding apparatus for performing TIG welding on a plurality of coils arranged circumferentially on an annular stator core, wherein, have: The welding clamping part control unit uses welding clamping parts to hold one end of the wiring constituting the coil, namely the coil end, and other wirings that are different from the coil. The electrode clamping control unit uses conductive electrode clamps to maintain an energized position on the other wiring that is different from the position of the object being welded; and The welding torch control unit controls the welding torch that connects the coil end to the other wiring via TIG welding.

6. The welding apparatus according to claim 5, wherein, The welding apparatus also includes a stator rotation control unit that rotates the stator core, causing the next coil end adjacent to the coil end to be welded to move in a direction opposite to the direction of rotation towards the position of the coil end before the rotation.

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