Connecting device

Abstract

When connecting the stator coil wires to power lines, etc., the connection area was sometimes not adequately secured due to misalignment between the objects being connected. [Solution] A joining device for ultrasonically joining the end of a coil wire arranged in a stator to the end of a power wire or neutral wire comprises an ultrasonic horn that is pressed against a second end, which is one end of the power wire or neutral wire, and a first end, which is one end of the coil wire, and an anvil that contacts the first end with the first end and the second end sandwiched between it and the ultrasonic horn, the anvil having a regulating portion that restricts the misalignment of the first end relative to the second end.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a joining device that ultrasonically joins the end of a coil wire disposed on a stator to the end of a power line or a neutral line.

Background Art

[0002] When joining the end of a coil wire disposed on a stator of a motor to the end of a power line or a neutral line, ultrasonic joining may be used.

[0003] Patent Document 1 discloses an ultrasonic joining method in which a container and a lid made of a metal material are set between an ultrasonic horn and an anvil and ultrasonically joined. According to this method, ultrasonic joining is performed with the container and the lid clamped by a jig.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] According to the above configuration, the anvil itself is equipped with a restricting portion that restricts the misalignment of the first end, which is one end of the coil wire, with respect to the second end, which is one end of the power wire or neutral wire. This makes it possible to suppress the misalignment and secure the joining area between the first end and the second end without using a separate jig. [Brief explanation of the drawing]

[0008] [Figure 1] A simplified diagram showing the structure of the stator. [Figure 2] A simplified diagram showing the relationship between the main parts of the joining device and the objects to be joined. [Figure 3] A simplified diagram showing a part of the configuration shown in Figure 2, viewed from above. [Figure 4] Figure 2 is a perspective view showing a part of the configuration. [Modes for carrying out the invention]

[0009] This embodiment will be described with reference to the drawings. Each figure is for illustrative purposes only, and this embodiment is not limited to what is shown. Also, since each figure is illustrative, some parts may be omitted.

[0010] Figure 1 shows a simplified perspective view of the structure of the stator 10. Figure 2 shows a simplified relationship between the main parts of the bonding device 20 and the objects to be bonded. The bonding device 20 is a device for ultrasonic bonding. The bonding device 20 bonds the "first end 13," which is one end of the coil wire 12 arranged on the stator 10, and the "second end 31," which is one end of the power line 30. As shown in Figure 1, the stator 10 comprises a stator core 11 and coil wires 12. Figure 2 shows a view of the stator core 11 facing in the circumferential direction. The stator 10 is a component of a motor driven by electric power. The concept of a motor includes various types of motors, such as DC (direct current) motors, AC (alternating current) motors, stepping motors, and servo motors.

[0011] The specific configuration and material of the stator core 11 are not particularly limited. For example, the stator core 11 is generally cylindrical in shape and is constructed by laminating multiple silicon steel plates. Multiple slits extending in the axial direction of the stator 10 are arranged along the circumferential direction on the inner circumferential surface of the stator core 11.

[0012] The coil wire 12 is positioned so as to pass through the slit in the stator core 11. The coil wire 12 is composed of multiple conductive wires having a rectangular cross-section called a segment coil. For example, the coil wire 12 is made of a metal wire such as copper. The coil wire 12 is, for example, a three-phase coil wire, and includes three coil wires 12 for the U phase, V phase, and W phase. The three coil wires 12 generate a rotating magnetic field in the stator core 11 when a three-phase alternating current is passed through them.

[0013] The power line 30 is electrically connected to a power source (not shown) and constitutes a path for supplying current to the coil wire 12. The power line 30 is made of a metal such as copper or aluminum. In each figure, only one second end 31 connected to a first end 13 is shown, but in reality, there are three power lines 30 and second end 31 for the U-phase, V-phase, and W-phase. Each second end 31 of the three power lines 30 is connected to the corresponding first end 13 of the three coil wires 12 for the U-phase, V-phase, and W-phase. Depending on the motor configuration, a so-called neutral wire may extend from the power source, and the end of the neutral wire may be connected to a certain end of the coil wire 12. In this embodiment, the second end 31 connected to a certain first end 13 of the coil wire 12 may be interpreted as the end of the neutral wire (30).

[0014] Next, the bonding device 20 will be described with reference to Figures 2, 3, and 4. Figure 3 shows a simplified view of part of the configuration shown in Figure 2 from above. Figure 4 shows a perspective view of part of the configuration shown in Figure 2. The bonding device 20 comprises an ultrasonic horn 21 and an anvil 22. Note that the ultrasonic horn 21 is omitted in Figures 3 and 4. The ultrasonic horn 21 is connected to an ultrasonic generator and is configured to vibrate ultrasonically. The ultrasonic horn 21 is pressed against the second end 31 which contacts the first end 13. The ultrasonic horn 21 contacts the surface 31a of the second end 31 opposite to the surface that contacts the first end 13.

[0015] The anvil 22 contacts the first end 13 with the first end 13 and the second end 31 sandwiched between it and the ultrasonic horn 21. That is, the first end 13 and the second end 31 are sandwiched between the ultrasonic horn 21 and the anvil 22 and are joined to each other by ultrasonic vibrations applied from the ultrasonic horn 21.

[0016] The surface of the anvil 22 that contacts the first end 13 is called the contact surface 22a. The anvil 22 is equipped with a restricting portion 23. The restricting portion 23 can restrict the displacement of the first end 13 relative to the second end 31. The displacement referred to here is a displacement in a direction intersecting the direction in which the ultrasonic horn 21 and the anvil 22 are clamped.

[0017] In Figures 2, 3, and 4, the direction in which the stator is clamped by the ultrasonic horn 21 and the anvil 22 is shown as direction D1. Direction D1 corresponds to the radial direction of the stator 10. As shown in Figures 3 and 4, direction D2, which is perpendicular to direction D1, is an example of a direction that intersects the direction in which the stator is clamped by the ultrasonic horn 21 and the anvil 22. Direction D2 roughly corresponds to the circumferential direction of the stator 10. Also, as can be seen from the shape of the first end 13 shown in Figure 4, direction D2 can be said to be one of the directions that intersects the longitudinal direction of the first end 13. For example, direction D1 may be called the first direction and direction D2 may be called the second direction.

[0018] The restricting section 23 includes protrusions 23a and 23b that project toward the ultrasonic horn 21 from one side and the other side in a direction (direction D2) that intersects the longitudinal direction of the first end 13. The restricting section 23 restricts the first end 13 by sandwiching it from one side and the other side in direction D2 with its protrusions 23a and 23b. In other words, when the anvil 22 and the ultrasonic horn 21 are set relative to the first end 13 and the second end 31 so as to sandwich them in direction D1, the protrusions 23a and 23b sandwich the first end 13 from one side and the other side in direction D2. As a result, displacement of the first end 13 in direction D2 is suppressed. Furthermore, the protrusions 23a and 23b protrude toward the ultrasonic horn 21 in direction D1 to an extent that does not exceed the thickness of the first end portion 13, beyond the contact surface 22a.

[0019] As can be seen from FIG. 1, the power line 30 (or the neutral line 30) approaches the first end portion 13 of the coil wire 12 from the outer peripheral side of the stator 10. Further, when the anvil 22 and the ultrasonic horn 21 sandwich the first end portion 13 and the second end portion 31 in the direction D1, the anvil 22 is disposed at a position closer to the central axis of the stator 10 than the ultrasonic horn 21. In such a configuration, it is relatively easy to regulate the position of the power line 30 including the second end portion 31. In the present embodiment, the position displacement of the power line 30 including the second end portion 31 in the direction D2 is regulated by a guide member (not shown) provided outside the stator 10. On the other hand, in the vicinity of the first end portion 13, the coil wires 12 are densely and complicatedly arranged, and the gap between the anvil 22 and the ultrasonic horn 21 is also narrow. Therefore, it has been difficult to regulate the position of the bonding target, particularly the first end portion 13, using a jig as in the prior art. In such a situation, in the present embodiment, the anvil 22 includes a regulating portion 23. Thereby, without using a jig, it is possible to suppress the displacement of the position of the first end portion 13 in the limited space near the first end portion 13 and appropriately secure the bonding area between the first end portion 13 and the second end portion 31.

[0020] Furthermore, in the present embodiment, the regulating portion 23 may be configured to perform the above-described regulation in contact with the covered portion 15 covered with the insulating member, which does not correspond to the tip portion 14 of the first end portion 13 that is not covered with the insulating member. In the first end portion 13, the coating (insulating coating) of the insulating member is peeled off in a predetermined range including the tip, and the metal wire is exposed. Such a predetermined range including the tip is the tip portion 14. The tip portion 14 contacts the contact surface 22a of the anvil 22, and the surface opposite to the surface contacting the contact surface 22a is joined to the second end portion 31. On the other hand, the range of the first end portion 13 excluding the tip portion 14 corresponds to the covered portion 15 covered with the insulating coating.

[0021] According to FIGS. 3 and 4, the covering portion 15 of the first end portion 13 is sandwiched by the protruding portions 23a and 23b. The covering portion 15 is thicker than the tip portion 14 by the thickness of the insulating film. Therefore, the protruding portions 23a and 23b do not contact the tip portion 14 and can contact the covering portion 15. That is, the gap between the protruding portion 23a and the protruding portion 23b in the direction D2 is provided in accordance with the width of the covering portion 15 in the direction D2.

[0022] During the joining process by the joining device 20, the tip portion 14 may be slightly crushed under the clamping force of the anvil 22 and the ultrasonic horn 21 and may expand in the direction D2. Therefore, if the restricting portion 23 contacts the tip portion 14 to perform position restriction, the crushed tip portion 14 cannot escape between the protruding portion 23a and the protruding portion 23b, and it becomes difficult to remove the joining device 20 from the stator 10. In contrast, the covering portion 15 does not crush like the tip portion 14. Therefore, by making the restricting portion 23 contact the covering portion 15 to perform the above-described restriction, a problem that it becomes difficult to remove the joining device 20 from the stator 10 does not occur.

[0023] Finally, based on the specific dimensions of the tip portion 14 of the first end portion 13 and the second end portion 31, this embodiment will be described. The width of the tip portion 14 in the direction D2 is, for example, 3.128 ± 0.1 mm including manufacturing errors, and the width of the second end portion 31 in the direction D2 is, for example,5.4 ± 0.1 mm including manufacturing errors. In this case, (5.3 - 3.228) ÷ 2 = 1.036 is the allowable value of the positional deviation between the first end portion 13 and the second end portion 31 in the direction D2. If the positional deviation between the first end portion 13 and the second end portion 31 in the direction D2 exceeds the allowable value of 1.036 mm, the joining area between the first end portion 13 and the second end portion 31, that is, the joining area between the tip portion 14 and the second end portion 31 may decrease. Note that the state where the centers of the first end portion 13 and the second end portion 31 coincide in the direction D2 is the state where there is no positional deviation between the first end portion 13 and the second end portion 31 in the direction D2.

[0024] As described above, the power line 30, including the second end portion 31, is restricted from misalignment in direction D2 by a guide member provided outside the stator 10. This guide member can, for example, suppress the misalignment of the second end portion 31 in direction D2 to 0.4 mm or less. Considering the misalignment suppression effect of this guide member and the aforementioned tolerance based on the dimensional difference between the second end portion 31 and the tip portion 14, in order to avoid a reduction in the joining area, the misalignment of the first end portion 13 in direction D2 should be kept to approximately 0.6 mm or less. Therefore, the restricting portion 23 in this embodiment is formed, for example, to suppress the misalignment of the first end portion 13 in direction D2 to 0.6 mm or less. As an example, the gap between the protrusions 23a and 23b in direction D2 is set to a width that suppresses the misalignment of the covering portion 15 in direction D2 to 0.6 mm or less.

[0025] The specific examples of the technologies disclosed herein have been described in detail above, but these are merely illustrative and do not limit the scope of the claims. The technologies described in the claims include various modifications and changes to the specific examples described above. Furthermore, the technical elements described herein or in the drawings exhibit technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technologies illustrated herein or in the drawings achieve multiple objectives simultaneously, and achieving even one of these objectives constitutes technical usefulness in itself. [Explanation of symbols]

[0026] 10: Stator, 11: Stator core, 12: Coil wire, 13: First end, 14: Tip, 15: Covering, 20: Joining device, 21: Ultrasonic horn, 22: Anvil, 23: Regulating part, 23a, 23b: Protruding part, 30: Power line, 31: Second end

Claims

1. A bonding device for ultrasonically bonding the ends of coil wires arranged in a stator to the ends of power lines or neutral wires, An ultrasonic horn is pressed against the second end, which is one end of the power line or the neutral line, which is in contact with the first end, which is one end of the coil wire. The ultrasonic horn is provided with an anvil that contacts the first end, with the first and second ends sandwiched between them. The joining device comprises an anvil with a restricting portion that restricts the misalignment of the first end relative to the second end.

2. The bonding device according to claim 1, wherein the restricting portion comprises protrusions that project toward the ultrasonic horn side from one side and the other side in a direction intersecting the longitudinal direction of the first end, and the restricting is performed by sandwiching the first end from the one side and the other side with the respective protrusions.

3. The joining device according to claim 1 or claim 2, wherein the restricting portion performs the restricting in contact with the covering portion covered by the insulating member, which is not the tip portion of the first end that is not covered by the insulating member.

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