Power line joining structure and joining method
The joining structure and method allow stator coil ends to be used as power lines without bending, ensuring a secure connection and space for equipment by extending and ultrasonically bonding power lines in the axial direction of a cylindrical stator core.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- TOYOTA JIDOSHA KK
- Filing Date
- 2024-11-05
- Publication Date
- 2026-05-19
AI Technical Summary
Existing methods require bending the end of a stator coil into a crank shape to use it as a power line, which is inefficient and may not provide sufficient space for equipment necessary for connection.
A joining structure and method where the ends of the first and second power lines extend radially and are joined in the axial direction of a cylindrical stator core using ultrasonic bonding, eliminating the need for a crank shape.
Enables the use of stator coil ends as power lines without bending, providing space for necessary equipment and ensuring a secure connection through ultrasonic bonding.
Smart Images
Figure 2026081575000001_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to a joining structure and a joining method for power lines.
Background Art
[0002] Patent Document 1 discloses that the end of a stator coil is bent into a crank shape and used as a power line, and the power line is joined to the wiring of an external power source by welding.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] However, in Patent Document 1, it is necessary to bend the end of the stator coil into a crank shape in order to use it as a power line. The present disclosure solves such problems, and provides a joining structure and a joining method for power lines that can be used as power lines without bending the ends of the stator coil into a crank shape.
Means for Solving the Problems
[0005] The present disclosure is a joining structure of a cylindrical stator core, a stator coil wound around the stator core, a first power line formed at an end of the stator coil, and a second power line connected to an external device, wherein the ends of the first power line and the second power line extend in the radial direction of the stator core and are joined while overlapping in the axial direction of the stator core. With such a configuration, it is possible to use the end of the stator coil as a power line without bending it into a crank shape.
[0006] The joint between the end of the first power line and the end of the second power line is formed radially outward of the stator core when viewed axially from the stator core. This configuration ensures space for the equipment necessary to connect the end of the first power line and the end of the second power line.
[0007] A method for joining a cylindrical stator core and a stator coil wound around the stator core, comprising a first power line formed at the end of the stator coil and a second power line connected to an external device, the method comprising the steps of: arranging the end of the first power line and the end of the second power line so as to extend radially across the stator core; overlapping the end of the first power line and the end of the second power line in the axial direction of the stator core; and joining the end of the first power line and the end of the second power line by ultrasonic bonding. This configuration allows the stator coil to be used as a power line without having to bend its ends into a crank shape. [Effects of the Invention]
[0008] This disclosure provides a power line joining structure and joining method that allows the stator coil ends to be used as power lines without being bent into a crank shape. [Brief explanation of the drawing]
[0009] [Figure 1] This is a schematic diagram of a stator to which the power line connection structure according to Embodiment 1 is applied. [Figure 2] This diagram shows the ultrasonic bonding process between the first and second power lines. [Modes for carrying out the invention]
[0010] The embodiments of this disclosure will be described below with reference to Figures 1 and 2. Figure 1 is a schematic diagram of a stator to which the power line joining structure according to Embodiment 1 is applied. Figure 2 is a diagram showing the ultrasonic joining of the first power line and the second power line.
[0011] It should be noted that the Z-axis coordinates shown in Figures 1 and 2 are merely for illustrative purposes to explain the positional relationships of the components. In Figures 1 and 2, the positive Z-axis direction is vertically upward.
[0012] Embodiment 1 Using Figure 1, a stator 20 to which the power line connection structure 10 according to Embodiment 1 is applied will be explained. The stator 20, in combination with a rotor (not shown), constitutes a rotating electric machine. A rotating electric machine is a rotating electrical machine that has the functions of both an electric motor and a generator, and is mounted on vehicles such as electric vehicles, hybrid vehicles, and fuel cell vehicles; it is a so-called motor generator.
[0013] As shown in Figure 1, the stator 20 includes a stator core 21, stator coils 22, a first power line 31, and a second power line 32.
[0014] The stator core 21 is formed in a substantially cylindrical shape, and consists of multiple substantially annular electromagnetic steel sheets stacked in the axial direction (Z-axis direction in Figure 1). Each electromagnetic steel sheet constituting the stator core 21 has substantially the same shape and is formed by punching or other processes.
[0015] The stator core 21 includes an annular yoke extending along the circumferential direction, a plurality of teeth protruding radially inward from the inner circumferential surface of the yoke, and a plurality of slots formed between the teeth (none of which are shown).
[0016] A stator coil 22 is wound around the stator core 21. The stator coil 22 is formed by electrically connecting multiple segment coils that are inserted into slots.
[0017] The stator coil 22 is a flat wire with a roughly rectangular cross-section. The stator coil 22 is formed from a metal or alloy material (e.g., copper wire, copper-tin alloy wire, silver-plated copper-tin alloy wire, etc.) and is covered with a coil film, leaving its ends exposed. As the coil film, an insulating material such as a polyamide-imide enamel film is used.
[0018] The stator coil 22 is a three-phase winding of U-phase, V-phase, and W-phase. At the end of each phase of the stator coil 22, a first power line 31 is formed. Three first power lines 31 are provided corresponding to each of the U-phase, V-phase, and W-phase. In FIG. 1, only one of the three first power lines 31 is shown.
[0019] The first power line 31 is formed in a substantially L shape in side view and is provided on the outer side in the axial direction of the stator core 21 (the positive Z-axis direction side in FIG. 1). The first power line 31 has an axial portion 31a constituting one side of the L shape and a radial portion 31b constituting the other side.
[0020] The axial portion 31a is formed on the stator core 21 side of the first power line 31 and extends along the axial direction of the stator core 21 (the Z-axis direction in FIG. 1).
[0021] The radial portion 31b is formed on the tip side of the first power line 31 and extends toward the outside in the radial direction of the stator core 21 (the right side in FIG. 1). The radial portion 31b is arranged such that the planar portion faces the axial direction of the stator core 21 (the Z-axis direction in FIG. 1). The tip side of the radial portion 31b protrudes outside in the radial direction (the right side in FIG. 1) from the outer periphery of the stator core 21 in the axial view of the stator core 21.
[0022] A second power line 32 is joined to the radial portion 31b of the first power line 31. The second power line 32 is formed of a metal material, an alloy material, etc. The second power line 32 is formed by bending a slender plate-like body into a crank shape in side view. The second power line 32 extends in the radial direction of the stator core 21. The second power line 32 is connected to an external device such as an inverter (none of which are shown) via a power line, and the external device such as an inverter supplies power to the stator coil 22.
[0023] The second power line 32 has a first radial portion 32a, an axial portion 32b, and a second radial portion 32c. The first radial portion 32a is formed on the stator core 21 side of the second power line 32 and extends radially from the stator core 21. The planar portion of the first radial portion 32a is positioned so that it faces the axial direction of the stator core 21 (the Z-axis direction in Figure 1).
[0024] The first radial portion 32a and the radial portion 31b of the first power line 31 are arranged to overlap in the axial direction of the stator core 21. The first radial portion 32a is positioned on the side closer to the stator core 21 than the radial portion 31b in the axial direction of the stator core 21 (the Z-axis direction in Figure 1).
[0025] The flat portion at the tip of the first radial portion 32a and the flat portion at the tip of the radial portion 31b are ultrasonically bonded. The joint 10a between the first radial portion 32a and the radial portion 31b is formed on the radially outward side of the stator core 21 when viewed in the axial direction of the stator core 21.
[0026] The axial portion 32b extends from the end of the first radial portion 32a opposite to the tip side in the axial direction of the stator core 21 (the Z-axis direction in Figure 1) toward the stator core 21.
[0027] The second radial section 32c extends radially outward from the stator core 21 (to the right in Figure 1) from the end of the axial section 32b opposite to the side connected to the first radial section 32a. The tip of the second radial section 32c is connected to external equipment such as an inverter via a power line.
[0028] Next, the method for joining the first power line 31 and the second power line 32 will be explained using Figure 2. Figure 2 shows the ultrasonic joining process of the first power line 31 and the second power line 32.
[0029] For ultrasonic bonding, a horn 50 and an anvil 60 are used. The horn 50 applies a load to the first power line 31 and the second power line 32, and imparts ultrasonic vibrations that vibrate radially to the stator core 21 using high-frequency power generated by an ultrasonic oscillator (not shown). The anvil 60 is a support jig that positions the first power line 31 and the second power line 32 between itself and the horn 50.
[0030] The joining method according to this disclosure first involves arranging the radial portion 31b of the first power line 31 and the first radial portion 32a of the second power line 32 so that they extend in the radial direction of the stator core 21.
[0031] Next, the radial portion 31b of the first power line 31 and the first radial portion 32a of the second power line 32 are superimposed in the axial direction of the stator core 21 (the Z-axis direction in Figure 2). In this disclosure, the radial portion 31b of the first power line 31 is positioned away from the stator core 21 in the axial direction of the stator core 21 (the Z-axis direction in Figure 2) relative to the first radial portion 32a of the second power line 32. Note that the arrangement of the radial portion 31b of the first power line 31 and the first radial portion 32a of the second power line 32 may be swapped.
[0032] Next, the horn 50 and anvil 60 are positioned so as to sandwich the radial portion 31b of the first power line 31 and the first radial portion 32a of the second power line 32. Specifically, the tip 51 of the horn 50 is positioned on the surface opposite to the joint 10a of the radial portion 31b of the first power line 31. The anvil 60 is also positioned on the surface opposite to the joint 10a of the first radial portion 32a of the second power line 32. Then, a load is applied from the tip 51 of the horn 50 to the radial portion 31b of the first power line 31, and an ultrasonic oscillator (not shown) is activated to apply ultrasonic vibrations. The joining by ultrasonic vibration is performed, for example, under conditions of a load of 500N, a frequency of 20kHz, an amplitude of 62μm, and an oscillation time of 500ms. In this way, the radial portion 31b of the first power line 31 and the first radial portion 32a of the second power line 32 are ultrasonically bonded, and a power line joint structure 10 is formed by the first power line 31 and the second power line 32.
[0033] In the power line joining structure 10 of this disclosure, the radial portion 31b of the first power line 31 formed at the end of the stator coil 22 and the first radial portion 32a of the second power line 32 extend radially to the stator core 21 and are joined to overlap in the axial direction of the stator core 21. Therefore, the end of the stator coil 22 can be used as a power line without bending it into a crank shape.
[0034] Furthermore, in the power line joining structure 10 of this disclosure, the joining portion 10a between the radial portion 31b of the first power line 31 and the first radial portion 32a of the second power line 32 is formed radially outward of the stator core 21 in an axial view of the stator core 21. This configuration makes it possible to secure space for the equipment necessary for joining the first power line 31 and the second power line 32. For example, when ultrasonic joining is performed between the first power line 31 and the second power line 32, space can be secured for the horn 50 and anvil 60 necessary for ultrasonic joining.
[0035] In the power line joining method of this disclosure, the radial portion 31b of the first power line 31 formed at the end of the stator coil 22 and the first radial portion 32a of the second power line 32 are joined by ultrasonic bonding. Therefore, the end of the stator coil 22 can be used as a power line without bending it into a crank shape.
[0036] This disclosure is not limited to the embodiments described above, and may be modified as appropriate without departing from its spirit. [Explanation of symbols]
[0037] 10. Power line connection structure 10a...Joint part 21... Stator core 22. Stator coil 31...1st power line 31a...Axial section 31b...Radial section 32...Second power line 32a...First radial section 32b...Axial section 32c...Second radial section
Claims
1. A cylindrical stator core, The stator has stator coils wound around the stator core, A connection structure between a first power line formed at the end of the stator coil and a second power line connected to an external device, The ends of the first power line and the ends of the second power line extend radially to the stator core and are joined to overlap in the axial direction of the stator core. Power line connection structure.
2. The joint between the end of the first power line and the end of the second power line is formed radially outward of the stator core when viewed in the axial direction of the stator core. The power line joining structure according to claim 1.
3. A cylindrical stator core, The stator has stator coils wound around the stator core, A method for joining a first power line formed at the end of the stator coil to a second power line connected to an external device, A step of arranging the ends of the first power line and the ends of the second power line so as to extend radially in the stator core, A step of overlapping the end of the first power line and the end of the second power line in the axial direction of the stator core, The process includes joining the end of the first power line and the end of the second power line by ultrasonic bonding, Method for joining power lines.