Terminal block support structure

Abstract

A terminal block support structure capable of suppressing a temperature rise in a current sensor is provided. [Solution] The terminal block support structure comprises a bus bar (20) that electrically connects a motor (50) and a PCU (60) that controls the motor (50), a PCU case (64) that houses the PCU (60), a terminal block (22) to which the bus bar (20) is fixed and placed on a seating surface (68) of the PCU case (64), a heat dissipation sheet (24) provided between the seating surface (68) and the terminal block (22), and a current sensor (28) fixed to the terminal block (22) that measures the current flowing through the bus bar (20), and a portion of the bus bar (20) extends along the surface of the heat dissipation sheet (24).

Description

[Technical Field]

[0001] The present invention relates to a terminal block support structure. [Background technology]

[0002] A configuration is known in which a motor and a power control unit are electrically connected by a cable fixed to a terminal block (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-152137 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to control the torque of a motor, the current flowing through a bus bar that electrically connects the motor and a power control unit is measured. The temperature of the bus bar rises due to heat received from the motor power line connected to the motor and heat generated by the current flowing through the bus bar. When the temperature of the bus bar rises, the temperature of the current sensor that measures the current flowing through the bus bar also rises, which can reduce the measurement accuracy of the current sensor or cause it to malfunction.

[0005] The present invention has been made in view of the above-mentioned problems, and has an object to suppress a temperature rise in a current sensor. [Means for solving the problem]

[0006] The present invention provides a terminal block support structure comprising: a bus bar electrically connecting a motor and a power control unit that controls the motor; a case that houses the power control unit; a terminal block to which the bus bar is fixed and placed on a seating surface of the case; a heat dissipation sheet provided between the seating surface and the terminal block; and a current sensor fixed to the terminal block and measuring the current flowing through the bus bar, wherein a portion of the bus bar extends along the surface of the heat dissipation sheet. [Effects of the Invention]

[0007] According to the present invention, it is possible to suppress a rise in temperature of the current sensor. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view showing a terminal block support structure according to an embodiment. [Figure 2] FIG. 2(a) is a plan view of the vicinity of the terminal block in the embodiment, and FIG. 2(b) is a cross-sectional view of the vicinity of the heat dissipation sheet. [Figure 3] FIG. 3 is a cross-sectional view showing a terminal block support structure according to a modified example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. [Example]

[0010] Fig. 1 is a cross-sectional view showing a terminal block support structure according to an embodiment. Fig. 2(a) is a plan view of the vicinity of a terminal block 22 in the embodiment, and Fig. 2(b) is a cross-sectional view of the vicinity of a heat dissipation sheet 24. As shown in Fig. 1, a bus bar 20 is provided to electrically connect a motor 50 and a power control unit (hereinafter referred to as "PCU") 60. The bus bar 20 is fixed to the terminal block 22. The motor 50, the PCU 60, and the terminal block 22 are mounted on, for example, an electric vehicle.

[0011] The motor 50 is a motor generator that functions as a power source for driving, and has a motor function and a power generation function. The power output by the motor 50 is transmitted to the wheels via a gear mechanism. The PCU 60 is a control device that controls the motor 50, and includes a power module 65 and a control board 67. The PCU 60 is electrically connected to the battery. The PCU 60 is electrically connected to the motor 50 via the bus bar 20, and therefore the motor 50 is electrically connected to the battery via the PCU 60.

[0012] The bus bar 20 is electrically connected to the motor 50 via a motor power line 52, and is also electrically connected to a power module 65 of the PCU 60 via a PCU power line 62. A connection portion 53 between the bus bar 20 and the motor power line 52 and a connection portion 63 between the bus bar 20 and the PCU power line 62 are fixed to the terminal block 22 by bolts 70 and nuts 72.

[0013] The motor 50 is housed in an internal space 56 defined by the motor case 54. The PCU 60 is housed in an internal space 66 defined between the motor case 54 and the PCU case 64. The terminal block 22 is placed on a seating surface 68 of the PCU case 64 located on the internal space 66 side. The bus bar 20 fixed to the terminal block 22 is L-shaped. One end of the L-shaped bus bar 20 forms a connection portion 53 with the motor power line 52, and the other end forms a connection portion 63 with the PCU power line 62.

[0014] The terminal block 22 extends from the internal space 66 to the internal space 56 through an opening provided in the motor case 54. A connection portion 53 between the bus bar 20 and the motor power line 52 is located in the internal space 56.

[0015] A seal member 74 is provided between the lower surface of the motor case 54 and the upper surface of the terminal block 22. The seal member 74 is, for example, a rubber gasket. As shown in FIG. 2( a), the seal member 74 is provided in an annular shape on the upper surface of the terminal block 22. The L-shaped bus bar 20 passes inside the seal member 74. The annular seal member 74 separates the internal space 56 in which the motor 50 is provided from the internal space 66 in which the PCU 60 is provided. The motor case 54 presses the seal member 74 toward the terminal block 22, and as a result, the terminal block 22 is pressed toward the seating surface 68 of the PCU case 64.

[0016] A heat dissipation sheet 24 is provided between the terminal block 22 and the seating surface 68. A portion of the bus bar 20 extends along the heat dissipation sheet 24. As shown in FIG. 2(b), the terminal block 22 has a recess 23 on a surface 25 that contacts the seating surface 68. The heat dissipation sheet 24 is disposed in the recess 23 and is in direct contact with the terminal block 22 and the seating surface 68. The terminal block 22 is in direct contact with the seating surface 68 in an area of ​​the surface 25 other than the recess 23. If the heat dissipation sheet 24 is insulating, the bus bar 20 is preferably in direct contact with the heat dissipation sheet 24. If the heat dissipation sheet 24 is conductive, it is preferable to have a thin insulating material such as resin between the bus bar 20 and the heat dissipation sheet 24.

[0017] The busbar 20 is formed of a metal material whose main component is, for example, copper or aluminum. The terminal block 22 is formed of a resin material whose main component is, for example, PPS (polyphenylene sulfide) resin. The motor case 54 and the PCU case 64 are formed of a metal material such as aluminum die-cast. The heat dissipation sheet 24 is formed of a resin material such as silicone resin containing inorganic powder or metal powder with high thermal conductivity, such as alumina or zinc oxide.

[0018] The temperature of the busbar 20 rises due to heat received from the motor power line 52 and heat generated by the current supplied from the PCU 60. However, since the busbar 20 has a portion extending along the heat dissipation sheet 24 provided between the terminal block 22 and the seating surface 68, the heat of the busbar 20 is dissipated to the heat dissipation sheet 24. Therefore, the temperature rise of the busbar 20 is suppressed.

[0019] A ferrite 26 is provided inside the terminal block 22, surrounding the periphery of the busbar 20. A current sensor 28 is fixed to the terminal block 22. The current sensor 28 is located, for example, between the heat dissipation sheet 24 and the connection portion 63 and fixed to the terminal block 22. The current sensor 28 measures the current flowing through the busbar 20. The current sensor 28 measures the current value flowing through the busbar 20, for example, by measuring the magnetic flux generated by the current flowing through the busbar 20. The current sensor 28 may be a cored type or a coreless type. The torque applied to the motor 50 can be estimated based on information indicating the relationship between the current value and torque and the current value measured by the current sensor 28. The current sensor 28 is electrically connected to a control board 67 by pins 29. The current sensor 28 is not directly connected to the busbar 20. The control board 67 is, for example, a printed wiring board such as an MG-ECU drive board.

[0020] The current sensor 28 is located near the bus bar 20 and fixed to the terminal block 22 to measure the current flowing through the bus bar 20. Therefore, the current sensor 28 is easily affected by the temperature of the bus bar 20. When the temperature of the bus bar 20 rises, the temperature of the current sensor 28 also rises, which may result in a decrease in the measurement accuracy of the current sensor 28 or in a malfunction. However, because a portion of the bus bar 20 extends along the heat dissipation sheet 24 provided between the terminal block 22 and the seating surface 68, the temperature rise of the bus bar 20 is suppressed, and as a result, the temperature rise of the current sensor 28 is also suppressed. This prevents a decrease in the measurement accuracy of the current sensor 28 or in a malfunction.

[0021] [Variations] Fig. 3 is a cross-sectional view showing a terminal block support structure according to a modified example of the embodiment. As shown in Fig. 3, a seal member 74 is provided between the side wall of the terminal block 22 and the side wall of the opening of the motor case 54. The other configurations are the same as those of the first embodiment, so a description thereof will be omitted.

[0022] 1 and 3 , the bus bar 20 electrically connecting the motor 50 and the PCU 60 is fixed to the terminal block 22 placed on the seating surface 68 of the PCU case 64. A heat dissipation sheet 24 is provided between the terminal block 22 and the seating surface 68. A portion of the bus bar 20 extends along the surface of the heat dissipation sheet 24. This allows heat from the bus bar 20 to be dissipated to the heat dissipation sheet 24, thereby suppressing a temperature rise in the bus bar 20. This makes it possible to suppress a temperature rise in the current sensor 28, which is fixed to the terminal block 22 and measures the current flowing through the bus bar 20. This makes it possible to suppress a decrease in the measurement accuracy of the current sensor 28, as well as the occurrence of malfunctions.

[0023] 2(b), the heat dissipation sheet 24 is disposed in a recess 23 formed on the surface 25 of the terminal block 22 that contacts the seating surface 68. For example, if the recess 23 were not formed on the surface 25 of the terminal block 22, the heat dissipation sheet 24 would bear most of the pressing force from the terminal block 22 toward the seating surface 68, which is generated when the motor case 54 presses the seal member 74 toward the terminal block 22. If the heat dissipation sheet 24 is formed from a resin material containing highly thermally conductive inorganic or metal powder, creep may occur if the heat dissipation sheet 24 continues to receive pressing force from the terminal block 22 for a long period of time. In this case, the sealing force of the seal member 74 may decrease. However, by disposing the heat dissipation sheet 24 in the recess 23, the pressing force from the terminal block 22 toward the seating surface 68 is directly applied to the seating surface 68 from the area of ​​the surface 25 other than the recess 23, thereby reducing the pressing force applied to the heat dissipation sheet 24. Therefore, the reduction in the sealing force of the seal member 74 can be suppressed.

[0024] Note that a recess may be provided in the seating surface 68 instead of or in addition to the surface 25 of the terminal block 22, and the heat dissipation sheet 24 may be provided in this recess. That is, a recess may be provided in the contact surface between the terminal block 22 and the seating surface 68, and the heat dissipation sheet 24 may be provided in this recess. Even in this case, the reduction in the sealing force of the seal member 74 can be suppressed.

[0025] 2(a), electronic components 76 such as a resolver which is a rotation angle sensor used to control the motor 50 and / or a thermistor which is a temperature sensor may be attached to the terminal block 22. The electronic components 76 may be electrically connected to the control board 67 (see FIG. 1) by pins.

[0026] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and variations are possible within the scope of the gist of the present invention as defined in the claims. [Explanation of symbols]

[0027] 20...busbar, 22...terminal block, 23...recess, 24...heat dissipation sheet, 25...surface, 26...ferrite, 28...current sensor, 29...pin, 50...motor, 52...motor power line, 53...connection portion, 54...motor case, 56...internal space, 60...PCU, 62...PCU power line, 63...connection portion, 64...PCU case, 65...power module, 66...internal space, 67...control board, 68...seating surface, 70...bolt, 72...nut, 74...sealing member, 76...electronic component

Claims

[Claim 1] a bus bar that electrically connects a motor and a power control unit that controls the motor; a case that houses the power control unit; a terminal block to which the bus bar is fixed and which is placed on a seating surface of the case; a heat dissipation sheet provided between the seating surface and the terminal block; a current sensor fixed to the terminal block and measuring a current flowing through the bus bar, A terminal block support structure, wherein a portion of the bus bar extends along the surface of the heat dissipation sheet.

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