Stator coil connection method

Abstract

The objective is to provide a method for joining stator coils that suppresses a decrease in the joint strength with the neutral wire busbar. [Solution] A method for joining stator coils, comprising: pressing a pressing member against the portion of a neutral wire busbar having a fixed portion fixed by a fixing member and a first joined portion separated from the fixed portion and to which the first stator coil of a motor has already been ultrasonically joined; and ultrasonically joining a second stator coil adjacent to the first stator coil of the motor to a second joined portion between the fixed portion and the pressing member of the neutral wire busbar while the portion is being pressed by the pressing member.

Description

Technical Field

[0001] The present invention relates to a method for joining stator coils.

Background Art

[0002] There is a technique for ultrasonic joining of the core wire of an electric wire to a terminal (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] It is conceivable to ultrasonically join a plurality of stator coils of a motor to a single neutral bus bar. During ultrasonic joining, vibrations occur in the neutral bus bar. There is a risk that this vibration will be transmitted to the stator coil that has already been ultrasonically joined to the neutral bus bar, reducing the joining strength between this stator coil and the neutral bus bar.

[0005] Therefore, an object of the present invention is to provide a method for joining stator coils in which a decrease in the joining strength with a neutral bus bar is suppressed.

Means for Solving the Problems

[0006] The above objective can be achieved by a stator coil joining method, which involves pressing a portion of a neutral wire busbar, which has a fixed portion fixed by a fixing member and a first joined portion that is separate from the fixed portion and to which the first stator coil of the motor has already been ultrasonically joined, between the fixed portion and the first joined portion with a pressing member, and while the portion is being pressed by the pressing member, ultrasonically joining a second stator coil adjacent to the first stator coil of the motor to a second joined portion between the fixed portion and the pressing member of the neutral wire busbar. [Effects of the Invention]

[0007] According to the present invention, a method for joining stator coils is provided in which a decrease in the joint strength with the neutral wire busbar is suppressed. [Brief explanation of the drawing]

[0008] [Figure 1] This is an explanatory diagram of the stator coil joining method in a comparative example. [Figure 2] This is an explanatory diagram of the stator coil joining method in this embodiment. [Modes for carrying out the invention]

[0009] Before describing the stator coil joining method in this embodiment, we will first describe the stator coil joining method in a comparative example. Figure 1 is an explanatory diagram of the stator coil joining method in a comparative example. Stator coils 21 to 23 are mounted adjacent to each other in the circumferential direction on the motor's stator core 10. Stator coils 21 to 23 are U-phase, V-phase, and W-phase coils, respectively. The ends of stator coils 21 to 23 are ultrasonically joined to the joined portions 31 to 33 of the neutral wire busbar 30, as will be described in more detail later. The neutral wire busbar 30 is fixed by a fixing member 40 so as not to shift position relative to the stator coils 21 to 23. The fixing member 40 engages with a fixed portion 34 between joined portions 32 and 33 to fix the neutral wire busbar 30.

[0010] In the comparative example, the tip of the stator coil 21 is first ultrasonically bonded to the bonded portion 31 of the neutral wire busbar 30. Next, the tip of the stator coil 22 is ultrasonically bonded to the bonded portion 32 of the neutral wire busbar 30. Then, the tip of the stator coil 23 is ultrasonically bonded to the bonded portion 33 of the neutral wire busbar 30. Here, the neutral wire busbar 30 vibrates during ultrasonic bonding. Therefore, when the tip of the stator coil 22 is ultrasonically bonded to the bonded portion 32, the bonded portion 32 vibrates. This vibration is transmitted to the bonded portion 31, which may reduce the bonding strength between the bonded portion 31 and the stator coil 21.

[0011] Figure 2 is an explanatory diagram of the stator coil joining method in this embodiment. Similar to the comparative example, the tip of the stator coil 21 is first ultrasonically joined to the joining portion 31 of the neutral busbar 30. The stator coil 21 corresponds to the first stator coil. The joining portion 31 corresponds to the first joining portion. Next, in this embodiment, unlike the comparative example, the portion between the joining portion 31 and the joining portion 32 of the neutral busbar 30 is pressed by a pressing member 50. In this state, the tip of the stator coil 22 is ultrasonically joined to the joining portion 32 of the neutral busbar 30. The stator coil 22 corresponds to the second stator coil. The joining portion 32 corresponds to the second joining portion. After that, the tip of the stator coil 23 is ultrasonically joined to the joining portion 33 of the neutral busbar 30.

[0012] Thus, when ultrasonically bonding the tip of the stator coil 22 to the bonded portion 32 of the neutral wire busbar 30, the portion between the bonded portion 32 and the bonded portion 31 of the neutral wire busbar 30 is held down by the pressing member 50. This suppresses the transmission of vibrations caused by ultrasonic bonding from the bonded portion 32 to the bonded portion 31. This suppresses a decrease in the bonding strength between the bonded portion 31 and the stator coil 21. Furthermore, when ultrasonically bonding the stator coil 23 to the bonded portion 33, the vibrations are suppressed from being transmitted to the bonded portion 32 by the fixing member 40. In this way, a decrease in the bonding strength between the stator coils 21-23 and the neutral wire busbar 30 is suppressed.

[0013] The retaining member 50 may be, for example, a clamping mechanism. Furthermore, a vibration-damping material, such as polyvinyl chloride, may be attached to the surface of the retaining member 50 that holds the neutral wire busbar 30. The force applied by the retaining member 50 to the neutral wire busbar 30 should preferably be such that the neutral wire busbar 30 does not undergo plastic deformation.

[0014] Although embodiments of the present invention have been described in detail above, the present invention is not limited to these specific embodiments, and various modifications and changes are possible within the scope of the gist of the present invention as described in the claims. [Explanation of symbols]

[0015] 10 Stator Cores 21 Stator coil (First stator coil) 22 Stator coil (2nd stator coil) 30 Neutral Line Busbar 31 Part to be joined (first part to be joined) 32 Part to be joined (second part to be joined) 40 Fixing member 50 Retaining member

Claims

[Claim 1] A neutral wire busbar having a fixed portion fixed by a fixing member and a first joined portion that is separate from the fixed portion and to which the first stator coil of the motor has already been ultrasonically bonded, the portion between the fixed portion and the first joined portion is pressed by a pressing member, With the aforementioned portion held in place by the pressing member, the second stator coil adjacent to the first stator coil of the motor is ultrasonically bonded to the second joint between the fixed portion of the neutral wire busbar and the pressing member. Method of joining stator coils.

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