Power converter

Abstract

To provide a power conversion device that can fix a flexible circuit board without increasing the number of components. [Solution] The power converter 1 comprises a power module 10 including a plurality of rigid substrates 30, electronic components 40 provided separately from the rigid substrates 30, and a flexible substrate 50 that electrically connects the plurality of rigid substrates 30, and a housing 15 that houses the power module 10, wherein the flexible substrate 50 is sandwiched between the electronic components 40 and the inner wall portion 16 of the housing 15 along the thickness direction of the flexible substrate 50.

Description

Technical Field

[0001] The present invention relates to a power conversion device provided in a vehicle.

Background Art

[0002] For example, in an electric vehicle that runs using electric energy, such as an automobile equipped with a motor as a driving power source (hybrid electric vehicle (HEV), plug-in hybrid electric vehicle (PHEV), battery electric vehicle (BEV), fuel cell electric vehicle (FCEV), etc.), a battery for driving the motor is mounted. When charging this battery or using the power stored in the battery, a power conversion device that converts a DC voltage of a predetermined voltage value into a DC voltage of a desired voltage value is used. In such a power conversion device, a plurality of substrates are provided, and these substrates are connected using, for example, a flexible substrate. As a technology related to such a flexible substrate, for example, there is one described in Patent Document 1 cited below.

[0003] Patent Document 1 describes a jig for transporting a substrate. In Patent Document 1, a flexible substrate is held via an adhesive material formed of a double-sided adhesive material on the surface of a flat substrate formed of a metal such as aluminum.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] As a method for fixing flexible circuit boards, possible methods include attaching them to adhesive material or fixing them with brackets, as described in Patent Document 1. However, in power conversion devices, using such adhesive materials or brackets for fixing increases the number of components.

[0006] Therefore, there is a need for a power conversion device that can fix a flexible circuit board without increasing the number of components. [Means for solving the problem]

[0007] The characteristic configuration of the power conversion device according to the present invention is a power module including a plurality of rigid substrates, electronic components provided separately from the rigid substrates, and flexible substrates that electrically connect the plurality of rigid substrates, and a housing that houses the power module, wherein at least a portion of the flexible substrate is sandwiched between the electronic components and the inner wall of the housing along the thickness direction of the flexible substrate.

[0008] With this configuration, the flexible circuit board is sandwiched between existing electronic components and the inner wall of the housing, eliminating the need for additional components to fix the flexible circuit board. Furthermore, the flexible circuit board can be easily secured. Therefore, it becomes possible to fix the flexible circuit board without increasing the number of components. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view of the vehicle's drive system. [Figure 2] This is a partial plan view of a power conversion device. [Figure 3] This is a cross-sectional view taken along line III-III in Figure 2. [Figure 4] This is a perspective view of a flexible circuit board. [Figure 5] This diagram shows the relationship between the flexible substrate and the flow path. [Modes for carrying out the invention]

[0010] The power conversion device according to the present invention is configured to allow for easy fixing of a flexible substrate. The power conversion device 1 of this embodiment will be described below. However, the power conversion device 1 is not limited to the following embodiment and can be modified in various ways without departing from its gist.

[0011] Figure 1 is a perspective view of the vehicle drive unit 100 in which the power converter 1 is installed. The vehicle drive unit 100 is mounted on a vehicle, and in Figure 1, the front side of the vehicle in the direction of travel is indicated by "F" and the rear side of the vehicle in the direction of travel is indicated by "B". Looking at the front side F in the direction of travel, the left side in the vehicle width direction is indicated by "L" and the right side in the vehicle width direction is indicated by "R". Furthermore, the upper side in the vertical direction of the vehicle is indicated by "U" and the lower side in the vertical direction of the vehicle is indicated by "D".

[0012] As shown in Figure 1, the vehicle drive system 100 comprises a power converter 1 and a traction drive system 2. The power converter 1 includes a power module 10 and is located in the upper part (upper vertical U) of the vehicle drive system 100. The traction drive system 2 includes a traction drive unit 20 and is located in the lower part (lower vertical D) of the vehicle drive system 100. Therefore, in this embodiment, the power module 10 and the traction drive unit 20 are arranged vertically (aligned vertically) along the vertical direction of the vehicle.

[0013] The driving unit 20 includes a motor 21A and a gear mechanism 21B that output power to enable the vehicle to move. The motor 21A and the gear mechanism 21B are arranged side by side along the vehicle width direction. In this embodiment, the motor 21A is located on the right side R in the vehicle width direction, and the gear mechanism 21B is located on the left side L in the vehicle width direction. The motor 21A is driven by the power module 10. The motor 21A and the gear mechanism 21B are connected via a motor shaft, and the rotation of the motor 21A is input to the gear mechanism 21B via the motor shaft. The gear mechanism 21B reduces the rotation of the motor 21A and outputs it from the gear shaft. The vehicle moves using the output of the motor 21A via the gear mechanism 21B.

[0014] The power module 10 comprises an OBC (On-Board Charger) board 12A, a motor drive board 12B, and a control board 12C that controls the OBC board 12A and the motor drive board 12B. An inverter and a converter are mounted on the OBC board 12A. The inverter is supplied with AC power consisting of AC voltage from the commercial power supply and converts the AC power into DC power including DC voltage. The converter is supplied with the DC power generated by the inverter and boosts the voltage value of the DC voltage that makes up the DC power supplied from the inverter to a DC voltage value necessary for charging the battery mounted on the vehicle. Therefore, the power module 10 is capable of supplying power to the vehicle's battery.

[0015] The motor drive board 12B is equipped with a drive inverter that controls the drive current for driving the motor 21A. The control board 12C is equipped with a control unit that controls the inverter and converter. Therefore, the power supply module 10 is capable of supplying power to the motor 21A. Note that the power supply module 10 does not necessarily need to include the OBC board 12A or the part of the control board 12C that controls the OBC board 12A (functional unit).

[0016] Figure 2 is a partial plan view of the power converter 1. Figure 3 is a cross-sectional image of line III-III in Figure 2. The power converter 1 comprises a power module 10 and a housing 15.

[0017] The power module 10 is composed of multiple (two in Figure 2) rigid substrates 30, an EMCASSY 40 (an example of an "electronic component"), and a flexible substrate 50.

[0018] The rigid board 30 is a so-called printed circuit board, and includes the OBC board 12A, motor drive board 12B, control board 12C, etc. For example, it may be a board equipped with a sensor for sensing the temperature of each of these boards, or a board equipped with a protection circuit.

[0019] EMCASSY40 is provided separately from the rigid substrate 30. It is inserted in series into the bus bar 60 used for power transmission to reduce the noise generated in the bus bar 60. The bus bars 60 are provided in a pair of positive and negative. In the example of FIG. 2, the bus bar 60 is fastened and fixed to the EMCASSY40 by bolts 70.

[0020] The flexible substrate 50 electrically connects two of the plurality of rigid substrates 30 to each other. Unlike the rigid substrate 30, the flexible substrate 50 is a bendable substrate. As shown in FIG. 2, the flexible substrate 50 is electrically connected to the rigid substrate 30 via a connector 31 provided on the rigid substrate 30.

[0021] The housing 15 houses the power module 10 and the traveling drive unit 20. In the housing 15, a first space is provided in the upper U in the vertical direction, and a second space partitioned from the first space is provided in the lower D in the vertical direction. The power module 10 is provided in the first space of the housing 15, and the traveling drive unit 20 is provided in the second space of the housing 15. The first space and the second space are partitioned by a partition plate having a flow path 19 (see FIG. 5) through which the cooling fluid flows. It is possible to cool the power module 10 by exchanging heat with the cooling fluid flowing through this flow path 19. Note that the housing 15 includes a first housing that houses the power module 10 and a second housing that houses the traveling drive unit 20, and the first housing and the second housing may be provided separately from each other. Further, the portion of the housing 15 that houses the traveling drive unit 20 includes a motor housing portion that houses the motor 21A and a gear housing portion that houses the gear mechanism 21B, and the motor housing portion and the gear housing portion may be provided separately from each other (separated).

[0022] The flexible substrate 50 is at least partially sandwiched between the EMC ASSY 40 and the inner wall portion 16 of the housing 15 along the thickness direction of the flexible substrate 50. The thickness direction of the flexible substrate 50 is the direction along the thickness of the flexible substrate 50, which corresponds to the vertical direction of the vehicle in this embodiment. The inner wall portion 16 of the housing 15 corresponds to the portion that forms the first space in the housing 15 where the flexible substrate 50 is accommodated. Therefore, the inner wall portion 16 includes not only the wall portion (not shown) standing upright along the vertical direction but also the bottom portion 17 extending along both the traveling direction and the vehicle width direction of the vehicle. In this embodiment, the flexible substrate 50 is placed on the bottom portion 17 of the first space in the housing 15 and is sandwiched in a state where the EMC ASSY 40 on the upper side in the vertical direction is fastened and fixed to the bottom portion 17 with bolts 71. In this embodiment, as shown in FIG. 2, a part of the portion of the flexible substrate 50 placed on the bottom portion 17 of the housing 15 is sandwiched between the bottom portion 17 and the EMC ASSY 40. Thereby, the flexible substrate 50 can be fixed to the housing 15. Of course, all of the portion of the flexible substrate 50 placed on the bottom portion 17 of the housing 15 may be sandwiched between the bottom portion 17 and the EMC ASSY 40.

[0023] In this embodiment, a hole portion 18 is provided in the bottom portion 17 of the housing 15. One end of the flexible substrate 50 is connected to the rigid substrate 30 as described above, and the other end passes through the hole portion 18 and is electrically connected to the rigid substrate 30 via a connector (not shown) of the rigid substrate 30 provided below.

[0024] As shown in Figure 3, the EMCASSY 40 is provided with a shielding section 80 on the side of the flexible substrate 50 to suppress noise propagation. The side of the flexible substrate 50 is the vertically downward side D of the EMCASSY 40. The noise is the noise superimposed on the busbar 60 electrically connected to the EMCASSY 40. The shielding section 80 is made of, for example, a metal plate. If the case of the EMCASSY 40 is made of resin, the shielding section 80 may be formed by integral molding. Of course, the shielding section 80 may also be fixed to the vertically downward side D of the EMCASSY 40. By providing such a shielding section 80 on the side of the flexible substrate 50 of the EMCASSY 40, the propagation of noise from the EMCASSY 40 to the flexible substrate 50 can be suppressed. Therefore, it is possible to suppress the superposition of noise on the signal transmitted through the flexible substrate 50.

[0025] When the flexible substrate 50 is held between the bottom 17 of the housing 15 and the EMCASSY 40, if excessive pressure is applied to the flexible substrate 50, or if the flexible substrate 50 rubs against the bottom 17 of the housing 15 or the EMCASSY 40, there is a possibility that the patterns (power lines and signal lines) formed on the flexible substrate 50 may break. Therefore, a protective member 85 may be provided between the flexible substrate 50 and the EMCASSY 40 to protect the flexible substrate 50 by covering at least the surface of the flexible substrate 50 facing the EMCASSY 40.

[0026] Figure 4 shows a perspective view of a flexible substrate 50 equipped with a protective member 85. In the example in Figure 4, the protective member 85 is made of a cylindrical body made of an elastic material (e.g., a rubber material), and the protective member 85 is provided so that the flexible substrate 50 is inserted through the inside of the cylindrical body. Therefore, in the example in Figure 4, the protective member 85 covers not only the upper vertical surface U of the flexible substrate 50 (the surface facing the EMCASSY 40), but also the lower vertical surface D (the surface facing the bottom 17 of the housing 15), and the sides. In this way, by covering not only the surface facing the EMCASSY 40 but also the surface facing the bottom 17 of the housing 15, it is less likely that defects such as pattern breakage will occur even if excessive pressure is applied to the flexible substrate 50 or if it rubs against the bottom 17 of the housing 15 or the EMCASSY 40.

[0027] In the example shown in Figure 4, the protective member 85 is provided with multiple (two in Figure 2) convex bodies 86 projecting toward the vertically upward U on its vertically upward U surface. The convex bodies 86 should be positioned so as to contact areas where the electronic component being clamped from the vertically upward U of the flexible substrate 50 does not need to receive a reaction force from the protective member 85. In other words, the convex bodies 86 should be positioned opposite areas of the electronic component being clamped from the vertically upward U of the flexible substrate 50 (EMCASSY40 in this example) where excessive pressure can be tolerated. This prevents excessive pressure from being applied to the electronic component.

[0028] Furthermore, as described above, the housing 15 is divided into a first space and a second space by a partition plate, and a flow path 19 through which cooling fluid flows is provided in the partition plate. When a flow path 19 is provided in the housing 15 in this way, it is preferable to house the flexible substrate 50 in the housing 15 such that, when viewed along the thickness direction, at least a portion of it overlaps with the flow path 19, as shown in Figure 5. Viewing along the thickness direction means viewing the flexible substrate 50 from the upper vertical side U. Therefore, in the example in Figure 5, the components are arranged in the following order from the upper vertical side U: EMCASSY 40, protective member 85, flexible substrate 50, protective member 85, and flow path 19. This allows the cooling fluid flowing through the flow path 19 to absorb heat and cool the flexible substrate 50.

[0029] [Other Embodiments] Next, other embodiments of the power converter 1 will be described.

[0030] In the above embodiment, the flow path 19 was described as being formed inside the partition plate of the housing 15. However, the flow path 19 may be formed in a flow path plate that is provided separately from the housing 15. In this case, it is natural that the flow path plate (the surface of the flow path plate) is also included in the inner wall portion 16 of the housing 15.

[0031] In the above embodiment, the power module 10 was described as being housed in a housing 15, and the flexible substrate 50 was provided on the bottom 17 of the housing 15. However, if the housing 15 is configured to include a flow path plate, the flexible substrate 50 may be provided on the flow path plate. In this case, the portion of the flow path plate on which the flexible substrate 50 is provided corresponds to the inner wall portion 16 of the housing 15. Therefore, the inner wall portion 16 of the housing 15 also includes the surface of the flow path plate.

[0032] In the above embodiment, the flexible substrate 50 was described as being sandwiched at least a portion between the EMCASSY 40 and the bottom portion 17 of the inner wall 16 of the housing 15 along the thickness direction of the flexible substrate 50. However, the flexible substrate 50 may also be sandwiched at least a portion between the EMCASSY 40 and the wall portion of the inner wall 16 of the housing 15 that rises from the bottom portion 17 along the thickness direction of the flexible substrate 50.

[0033] In the above embodiment, the electronic component was described as EMCASSY40. However, the electronic component may be, for example, a capacitor provided on the busbar 60, or it may be another unit or module different from a capacitor.

[0034] In the above embodiment, the EMCASSY40 was described as having a shielding section 80 on the flexible substrate 50 side to suppress noise propagation. However, the EMCASSY40 does not necessarily have to have a shielding section 80.

[0035] In the above embodiment, it was explained that a protective member 85 is provided between the flexible substrate 50 and the EMCASSY 40 to protect the flexible substrate 50 by covering at least the surface of the flexible substrate 50 facing the EMCASSY 40. However, it is not necessary to provide a protective member 85 between the flexible substrate 50 and the EMCASSY 40 to protect the flexible substrate 50. In this case, for example, a protective member to protect the flexible substrate 50 may be provided on the part of the EMCASSY 40 that sandwiches the flexible substrate 50 between the inner wall 16 of the housing 15 and the flexible substrate 50, or a protective processing may be applied to that part.

[0036] In the above embodiment, the protective member 85 was described as being composed of a cylindrical body made of an elastic material (for example, a rubber material). However, the protective member 85 may be a coating applied to the flexible substrate 50 to reduce friction. Even in this case, problems caused by friction between the flexible substrate 50 and the inner wall portion 16 of the EMCASSY 40 or housing 15 are less likely to occur. The inner wall portion 16 of the EMCASSY 40 or housing 15 may be coated to reduce friction.

[0037] In the above embodiment, it was described that a passage 19 through which a cooling fluid flows is formed in a partition plate that divides the inside of the housing 15. For example, the housing 15 may consist of a cooling plate with a passage 19 formed inside and a member separate from the cooling plate.

[0038] In the above embodiment, the flexible substrate 50 was described as being housed in the housing 15 such that at least a portion of it overlaps with the flow path 19 when viewed along the thickness direction. However, the flexible substrate 50 may be housed in the housing 15 such that at least a portion of it does not overlap with the flow path 19 when viewed along the thickness direction.

[0039] [Summary of the above embodiment] The following describes the overview of the power converter 1 described above.

[0040] (1) The power converter 1 comprises a power module 10 including a plurality of rigid substrates 30, an EMCASSY 40 (electronic component) provided separately from the rigid substrates 30, and a flexible substrate 50 that electrically connects the plurality of rigid substrates 30, and a housing 15 that houses the power module 10, wherein at least a portion of the flexible substrate 50 is sandwiched between the EMCASSY 40 and the inner wall portion 16 of the housing 15 along the thickness direction of the flexible substrate 50.

[0041] With this configuration, the flexible substrate 50 is sandwiched between the existing component EMCASSY 40 and the inner wall portion 16 of the housing 15, eliminating the need to add any additional components for fixing the flexible substrate 50. Furthermore, the flexible substrate 50 can be easily fixed. Therefore, it is possible to fix the flexible substrate 50 without increasing the number of components.

[0042] (2) In the power conversion device 1 described in (1), it is preferable that the EMCASSY 40 is provided with a shielding portion 80 on the side of the flexible substrate 50 to suppress the propagation of noise.

[0043] This configuration suppresses the propagation of noise to the flexible substrate 50. Therefore, since there is no need to mount noise-reducing components on the flexible substrate 50 itself, cost increases can be kept to a minimum.

[0044] (3) In the power conversion device 1 described in (1) or (2), it is preferable that a protective member 85 is provided between the flexible substrate 50 and the EMCASSY 40 to cover at least the surface of the flexible substrate 50 facing the EMCASSY 40 and protect the flexible substrate 50.

[0045] With this configuration, the protective member 85 can prevent abrasion of the flexible substrate 50. Therefore, the deterioration of the flexible substrate 50 can be reduced.

[0046] (4) In the power conversion device 1 described in (1) or (2), the housing 15 is provided with a flow path 19 through which a cooling fluid flows, and it is preferable that the flexible substrate 50 is housed in the housing 15 such that at least a portion of it overlaps with the flow path 19 when viewed along the thickness direction.

[0047] This configuration reduces the thermal impact from the power module 10 on the flexible circuit board 50. [Industrial applicability]

[0048] The technology disclosed herein can be used in power conversion devices installed in vehicles. [Explanation of symbols]

[0049] 1: Power converter, 10: Power module, 15: Housing, 16: Inner wall, 19: Flow path, 30: Rigid substrate, 40: EMCASSY (electronic component), 50: Flexible substrate, 80: Shielding section, 85: Protective member

Claims

1. A power supply module including multiple rigid substrates, electronic components provided separately from the rigid substrates, and flexible substrates that electrically connect the multiple rigid substrates, The power supply module is housed in a housing, The power conversion device wherein the flexible substrate is sandwiched at least a portion between the electronic component and the inner wall of the housing along the thickness direction of the flexible substrate.

2. The power conversion device according to claim 1, wherein the electronic component is provided with a shield portion on the flexible substrate side for suppressing noise propagation.

3. The power conversion device according to claim 1 or 2, wherein a protective member is provided between the flexible substrate and the electronic component, covering at least the surface of the flexible substrate facing the electronic component to protect the flexible substrate.

4. The housing is provided with a passage through which a cooling fluid flows, The power conversion device according to claim 1 or 2, wherein the flexible substrate is housed in the housing such that, when viewed along the thickness direction, at least a portion of it overlaps with the flow path.

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