Electric power conversion device

Abstract

To provide an electric power conversion device that enables use of a voltage conversion section corresponding to specifications of a vehicle.SOLUTION: An electric power conversion device includes: a first housing Hm that accommodates at least an inverter 6 to which high-voltage electric power is supplied from a battery to drive a traveling motor 4; and second housings Ha, Hb that accommodate a voltage conversion section for converting the high-voltage electric power of the battery into low-voltage electric power. An attachment / detachment section 7 for supporting the second housings Ha, Hb in an attachable / detachable manner is formed in the first housing Hm.SELECTED DRAWING: Figure 2

Description

Technical Field

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

Background Art

[0002] Patent Document 1 describes a block-type power module including a power element substrate, a frame structure in which a plurality of terminals conducting to the power element substrate are arranged, and a power system printed circuit board, and the frame structure is configured to be detachable from a fixed body, and a power conversion device incorporating a plurality of the block-type power modules is described.

[0003] The power conversion device of this Patent Document 1 is configured as an in-vehicle device, and modules independent for each function (control board, block-type power module of PFC circuit, block-type power module of DC-DC converter) are each configured to be detachable. Thereby, when a failure or malfunction occurs, it is possible to cope by replacing the module in which the failure or the like has occurred.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] As vehicles that can run by the power of a battery, there are battery vehicles (BEV: Battery Electric Vehicle), hybrid vehicles (HEV: Hybrid Electric Vehicle), plug-in hybrid vehicles (PHEV: Plug-in Hybrid Electric Vehicle), etc. In these vehicles, high-voltage batteries such as 800V and 600V are used.

[0006] In addition, in a vehicle that can run on battery power, a drive motor for running and a reduction gear that reduces the driving force of the drive motor and transmits it to the wheels are housed in a housing, and a power conversion device such as an inverter that controls the power supplied from the battery power to the drive motor is provided. The development of vehicle drive devices is underway.

[0007] In a vehicle that can run on battery power, it is common for the power supply voltages of in-vehicle devices such as air conditioners, system batteries, audio systems, and car navigation systems to be lower than the battery voltage.

[0008] The presence or absence of in-vehicle devices is determined by the vehicle specifications. For example, in order to accommodate the specifications of many vehicle models, the development of a vehicle drive device equipped with a voltage conversion unit such as a DCDC converter that steps down the voltage supplied from the battery is also being considered. However, in a device equipped with a voltage conversion unit that converts to a voltage corresponding to multiple specifications, multiple types of vehicle drive devices are required.

[0009] For example, when designing a vehicle with a specification that places the vehicle drive device at the rear of the vehicle body and the air conditioner at the front of the cabin, a power cable for supplying the power stepped down by the voltage conversion unit of the vehicle drive device to the air conditioner at the front of the cabin is arranged in the area extending from the vehicle drive device at the rear of the vehicle body to the front of the vehicle body.

[0010] In particular, in a configuration where a vehicle drive device is equipped with a plurality of voltage conversion units, although it is possible to use a vehicle drive device with a configuration determined corresponding to multiple specifications, depending on the specifications, it will be equipped with a voltage conversion unit that is not required, resulting in an increase in the weight of the vehicle drive device and an increase in cost.

[0011] Therefore, when using the technology described in Patent Document 1 to configure a vehicle drive device that conforms to the vehicle specifications, it only enables the replacement of modules in response to failures and malfunctions, and the convenience is low.

[0012] For these reasons, there is a need for a power conversion device that enables the use of a voltage conversion unit corresponding to the specifications of a vehicle.

Means for Solving the Problem

[0013] The characteristic configuration of the power conversion device according to the present invention includes a first housing that houses at least an inverter that is supplied with high-voltage power from a battery and drives a driving motor, and a second housing that houses a voltage conversion unit that converts the high-voltage power of the battery into low-voltage power, and a detachable portion that detachably supports the second housing is formed in the first housing.

[0014] According to this configuration, by attaching the second housing to the detachable portion formed in the first housing, the power conversion device can be used in a form in which the high-voltage power of the battery is converted into low-voltage power by the voltage conversion unit of the second housing and supplied to electrical equipment. Also, for example, by attaching the second housing to the first housing and converting the power from the battery into low-voltage power by the voltage conversion unit of the second housing, it is possible to supply the power of the voltage required for the electrical equipment without arranging a power cable between the first housing and the electrical equipment. Furthermore, when there is no electrical equipment that requires the power of the voltage converted by the voltage conversion unit of the second housing, it is also possible to remove the second housing from the first housing. In this way, it is possible to correspond to the specifications of the vehicle, such as the positional relationship between the first housing and the electrical equipment, and the presence or absence of the use of the power of the required voltage. Therefore, a power conversion device that enables the use of a voltage conversion unit corresponding to the specifications of a vehicle is configured.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0016] Hereinafter, embodiments of a power conversion device according to the present invention will be described with reference to the drawings. In the present embodiment, a vehicle drive device has a first housing, and this first housing will be described as detachably supporting a second housing. However, without being limited to the following embodiments, the arrangement of the second housing and the configuration for attachment and detachment can be variously modified within a range not departing from the gist thereof.

[0017] 〔Basic Configuration of the First Embodiment〕 As shown in FIG. 1, a battery B configured as a secondary battery is provided at the center of a vehicle body A provided with front wheels 1 and rear wheels 2, and a vehicle drive device D (which also functions as a power conversion device DX) is arranged at the rear of the vehicle body A, whereby a battery vehicle (BEV: Battery Electric Vehicle) is configured.

[0018] This battery vehicle is an example of a vehicle that drives and travels the rear wheels 2 by supplying electric power from the battery B to the vehicle drive device D. As a vehicle that can travel by the electric power supplied from the battery B in this way, a hybrid vehicle (HEV: Hybrid Electric Vehicle), a plug-in hybrid vehicle (PHEV: Plug-in Hybrid Electric Vehicle), etc. may be used.

[0019] As shown in FIGS. 1 and 2, the vehicle drive device D has a structure in which a traveling motor 4 configured as a three-phase AC motor, a gear reduction mechanism 5 that reduces the driving force of the traveling motor 4 and transmits it to the rear wheels 2, and an inverter 6 that converts DC power supplied from the battery B into AC power and supplies it to the traveling motor 4 are housed in a main housing Hm (an example of a first housing).

[0020] The battery B supplies 800V DC high-voltage power, and the vehicle drive device D also functions as a power conversion device DX in which an inverter 6 that drives the traveling motor 4 by supplying high-voltage power from the battery B is housed in a main housing Hm (the first housing).

[0021] The vehicle drive device D (power conversion device DX) includes a high-voltage side housing Ha (an example of a second housing) and a low-voltage side housing Hb (an example of a second housing) that are detachably attached to the main housing Hm (the first housing).

[0022] As shown in FIGS. 1 to 4, the high-voltage side housing Ha includes a high-voltage conversion board 22 (an example of a voltage conversion unit) that converts the DC high-voltage power supplied from the battery B into 400V DC voltage. Further, the low-voltage side housing Hb includes a low-voltage conversion board 25 (an example of a voltage conversion unit) that converts the DC high-voltage power supplied from the battery B into 12V DC power. The arrangement of these voltage conversion units and the configuration for supplying power will be described later.

[0023] 〔Cooling Circuit〕 As shown in FIG. 5, the vehicle drive device D (power conversion device DX) includes a cooling circuit C that can cool a power control board including the inverter 6 and can cool the traveling motor 4 and the gear reduction mechanism 5.

[0024] The cooling circuit C includes a cooling water flow path L1 through which cooling water (an example of a cooling fluid), such as long-life coolant (LLC) containing ethylene glycol, propylene glycol, etc., circulates, a refrigerant flow path L2 through which a refrigerant such as hydrofluorocarbon (HFC) or hydrofluoroolefin (HFO) flows, and a lubricating oil flow path L3 through which lubricating oil circulates. Note that the cooling fluid may be insulating oil such as paraffin-based oil, or a refrigerant such as hydrofluorocarbon (HFC) or hydrofluoroolefin (HFO).

[0025] In the cooling water flow path L1, cooling water is circulated by a cooling water pump 10. This cooling water flow path L1 supplies cooling water to a switching valve 11 that switches the flow of the cooling water, a radiator 12 to which the cooling water is supplied by the switching operation of the switching valve 11, a water-cooled condenser 13, and an oil cooler 14.

[0026] The cooling water flow path L1 is formed so as to supply cooling water to an inverter 6, a high-pressure side cooling plate L1a (an example of a cooling plate) that contacts the outer surface of the high-pressure side housing Ha, and a low-pressure side cooling plate L1b (an example of a cooling plate) that contacts the outer surface of the low-pressure side housing Hb. The cooling of the high-pressure side housing Ha and the low-pressure side housing Hb will be described later.

[0027] In the water-cooled condenser 13, heat is given to the cooling water by supplying a refrigerant from the outside of the main housing Hm, and the temperature of the cooling water rises. Note that the switching valve 11 switches the flow path so as to supply and stop the supply of the cooling water to the radiator 12.

[0028] In the lubricating oil flow path L3, lubricating oil is circulated by an oil pump 15. By supplying the lubricating oil flowing in this lubricating oil flow path L3 to the traveling motor 4 and the gear reduction mechanism 5, lubrication and cooling of these are enabled.

[0029] The oil cooler 14 takes away the heat of the lubricating oil flowing in the lubricating oil flow path L3 with the cooling water flowing in the cooling water flow path L1, and realizes a temperature drop of the lubricating oil.

[0030] By configuring the cooling circuit C in this way, the inverter 6 is cooled, and cooling of the high-voltage conversion board 22 (voltage conversion unit) of the high-voltage side housing Ha shown in FIG. 3 and the low-voltage conversion board 25 (voltage conversion unit) of the low-voltage side housing Hb shown in FIG. 4 is achieved.

[0031] 〔Battery, Inverter〕 The inverter 6 converts the DC high-voltage power supplied from the battery B into three-phase AC power of a set frequency and supplies it to the traveling motor 4, thereby enabling the rear wheels 2 to be driven at a speed corresponding to the set speed.

[0032] In addition, the vehicle body A is provided with a control unit (not shown) configured as an ECU for controlling the traveling speed. The set speed is determined by the depression amount of an accelerator pedal (not shown), and the control unit sets a target traveling speed based on the depression amount of the accelerator pedal and controls the frequency set in the inverter 6 based on parameters such as the load acting during traveling so as to enable traveling at the traveling speed thus set. In particular, the inverter 6 includes a plurality of power semiconductors on a substrate, and since a relatively large current flows through each power semiconductor and generates heat, it is cooled by the cooling circuit C.

[0033] 〔Main Housing, In-Vehicle Equipment〕 As shown in FIGS. 3 to 4, the main housing Hm (first housing) has a high-voltage side attachment / detachment portion 7a (an example of the attachment / detachment portion 7) that serves as a fitting space into which the high-voltage side housing Ha (second housing) can be fitted, and a low-voltage side attachment / detachment portion 7b (an example of the attachment / detachment portion 7) that serves as a fitting space into which the low-voltage side housing Hb (second housing) can be fitted. In addition, the main housing Hm, the high-voltage side housing Ha, and the low-voltage side housing Hb are formed of a metal such as aluminum.

[0034] Also, in the high-voltage side attachment / detachment portion 7a (attachment / detachment portion 7), the fitting surface into which the high-voltage side housing Ha is fitted is referred to as the high-voltage side fitting wall 7aw. Also, in the low-voltage side attachment / detachment portion 7b (attachment / detachment portion 7), the fitting surface into which the low-voltage side housing Hb is fitted is referred to as the low-voltage side fitting wall 7bw.

[0035] As shown in FIG. 1, the vehicle body A is provided with an air-conditioning device 20 such as an air conditioner for controlling the temperature inside the cabin and an information output device 21 such as a navigation system and an audio device at the front position of the cabin. The air-conditioning device 20 operates with a 400V DC power supply, and the information output device 21 operates with a 12V DC power supply. Further, the vehicle body A is provided with a system battery (not shown), and this system battery outputs DC power with a voltage of 12V and is charged with 12V DC power.

[0036] 〔High-voltage side housing〕 As shown in FIG. 3, the high-voltage side housing Ha is configured as a metal housing sized to fit into the high-voltage side detachable part 7a (detachable part 7). This high-voltage side housing Ha houses a DC-DC converter type high-voltage conversion substrate 22 (voltage conversion part) that converts 800V DC high-voltage power supplied from the battery B into DC power with a voltage of 400V, and functions as a 400V DC power supply.

[0037] A high-voltage side power socket part Pa that outputs power from the battery B to a predetermined high-voltage side fitting wall 7aw of the high-voltage side detachable part 7a and a high-voltage side control socket part Ca that outputs a control signal to the high-voltage conversion substrate 22 (voltage conversion substrate) are formed. Further, a high-voltage side cooling plate L1a (cooling plate) provided in a partial region of the above-described cooling water flow path L1 is disposed in an exposed state with respect to a high-voltage side fitting wall 7aw (an example of a notch surface) different from the high-voltage side fitting wall 7aw where the high-voltage side power socket part Pa is formed.

[0038] The high-voltage side housing Ha has a protruding high-voltage side power jack part PJa connectable to the high-voltage side power socket part Pa and a high-voltage side control jack part CJa connectable to the high-voltage side control socket part Ca. Further, this high-voltage side housing Ha is provided with a high-voltage output cable 23 and a high-voltage connector 24 for taking out the DC power converted to 400V.

[0039] From this configuration, by fitting the high-pressure side housing Ha into the high-pressure side detachable part 7a, the high-pressure side power socket part Pa and the high-pressure side control socket part Ca corresponding to the high-pressure side power jack part PJa and the high-pressure side control jack part CJa are connected, and 400V DC power is taken out from the high-pressure connector 24.

[0040] The connection part K is constituted by each of the high-pressure side power socket part Pa and the high-pressure side power jack part PJa. This connection part K can be mechanically separated and functions to supply power in the connected state.

[0041] Also, in a state where the high-pressure side housing Ha is fitted into the high-pressure side detachable part 7a, a plurality (two in this embodiment) of bolts 17 are used to fix the high-pressure side housing Ha to the main housing Hm. By maintaining the fitting state with the bolts 17 in this way, the connection of the connection part K is maintained.

[0042] In addition, instead of the configuration using the bolts 17 as a configuration for fixing the high-pressure side housing Ha to the main housing Hm, for example, a configuration using a buckle that fixes the two members in a pulled-together state, or a stopper that is switchable between a position for preventing detachment and a position for enabling separation can be used.

[0043] In particular, in a state where the high-pressure side housing Ha is fitted into the high-pressure side detachable part 7a, these positional relationships are set so that the high-pressure side cooling plate L1a formed on the wall part of the high-pressure side housing Ha comes into contact. From this configuration, in a state where the high-pressure side housing Ha is fitted into the high-pressure side detachable part 7a, the temperature of the outer wall of the high-pressure side housing Ha is lowered by the cooling water flowing through the high-pressure side cooling plate L1a, and as a result, the temperature rise of the high-voltage conversion substrate 22 is suppressed.

[0044] 〔Low-pressure side housing〕 As shown in FIG. 4, the low-pressure side housing Hb is configured as a metal housing sized to fit into the low-pressure side detachable portion 7b (detachable portion 7). This low-pressure side housing Hb houses a DC-DC converter type low-voltage conversion board 25 (voltage conversion portion) that converts 800V DC power supplied from the battery B into 12V DC power, and functions as a 12V DC power source.

[0045] A low-pressure side power socket portion Pb that outputs power from the battery B to a predetermined low-pressure side fitting wall 7bw of the low-pressure side detachable portion 7b and a low-pressure side control socket portion Cb that outputs a control signal to the low-voltage conversion board 25 (voltage conversion board) are formed. Further, a low-pressure side cooling plate L1b (cooling plate) provided in a part of the aforementioned cooling water flow path L1 is disposed in an exposed state with respect to a low-pressure side fitting wall 7bw (an example of a notch surface) different from the low-pressure side fitting wall 7bw where the low-pressure side power socket portion Pb is formed.

[0046] The low-pressure side housing Hb has a protruding low-pressure side power jack portion PJb connectable to the low-pressure side power socket portion Pb and a protruding low-pressure side control jack portion CJb connectable to the low-pressure side control socket portion Cb. Further, this low-pressure side housing Hb is provided with a low-voltage output cable 26 and a low-voltage connector 27 for taking out the DC power converted to 12V.

[0047] With such a configuration, by fitting the low-pressure side housing Hb into the low-pressure side detachable portion 7b, the corresponding low-pressure side power socket portion Pb and low-pressure side control socket portion Cb are connected to the low-pressure side power jack portion PJb and the low-pressure side control jack portion CJb, and 12V DC power is taken out from the low-voltage connector 27.

[0048] A connection portion K is formed by each of these low-pressure side power socket portion Pb and low-pressure side power jack portion PJb. This connection portion K can be mechanically separated and functions to supply power in the connected state.

[0049] Also, in a state where the low-pressure side housing Hb is fitted into the low-pressure side detachable portion 7b, a plurality (two in this embodiment) of bolts 17 are used to fix the low-pressure side housing Hb to the main housing Hm. By maintaining the fitting state with the bolts 17 in this way, the connection of the connection portion K is maintained.

[0050] Instead of using the bolts 17 as a configuration for fixing the low-pressure side housing Hb to the main housing Hm, a configuration using a buckle that fixes the two members in a state of being pulled together, as described above, or a stopper that is switchable between a position for preventing detachment and a position for enabling separation can be used.

[0051] In particular, in a state where the low-pressure side housing Hb is fitted into the low-pressure side detachable portion 7b, these positional relationships are set so that the low-pressure side cooling plate L1b formed on the wall portion of the low-pressure side housing Hb comes into contact. From this configuration, in a state where the low-pressure side housing Hb is fitted into the low-pressure side detachable portion 7b, the temperature of the outer wall of the low-pressure side housing Hb is lowered by the cooling water flowing through the low-pressure side cooling plate L1b, and as a result, the temperature rise of the low-voltage conversion substrate 25 is suppressed.

[0052] Incidentally, the high-pressure side housing Ha and the low-pressure side housing Hb removed from the main housing Hm are cooled by a dedicated cooling device.

[0053] 〔Protection of the detachable portion〕 The vehicle drive device D may be used in a form in which the high-pressure side housing Ha (second housing) is removed from the high-pressure side detachable portion 7a (detachable portion 7) of the main housing Hm (first housing) and the low-pressure side housing Hb is removed from the low-pressure side detachable portion 7b (detachable portion 7) according to the specifications of the vehicle body A.

[0054] Thus, when used with at least one of the second housings removed from the main housing Hm (the first housing), a resin cover material (not shown) is fixed using bolts so as to cover the space of the detachable portion 7 from which the second housing has been removed. Note that the cover material may have a shape equal to that of the second housing, or may have a plate shape that covers the connection portion K.

[0055] By fixing the cover material to cover the detachable portion 7 from which the second housing has been removed, the socket portion exposed inside the detachable portion 7 is protected, entry of dust is prevented, and the inconvenience of causing the temperature of the cooling water flowing through the cooling pipeline exposed on the wall portion of the detachable portion 7 to rise uselessly can be eliminated.

[0056] 〔Power supply form〕 The vehicle body A shown in FIG. 1 is designed such that the vehicle drive device D is arranged at the rear part of the vehicle body A, and the air conditioner 20 and the information output device 21 are arranged at the front position of the cabin.

[0057] Also, a main power line PL for supplying power from the rear end side of the battery B to the inverter 6 is formed between the main housing Hm. To correspond to this specification, the high-voltage side housing Ha and the low-voltage side housing Hb are removed from the main housing Hm of the vehicle drive device D, and the removed high-voltage side housing Ha and low-voltage side housing Hb are provided at the front position of the vehicle body A.

[0058] The battery B transmits power from the front end of the battery B to the high-voltage side power jack portion PJa (see FIG. 3) of the high-voltage side housing Ha and the low-voltage side power jack portion PJb (see FIG. 4) of the low-voltage side housing Hb through a front power line PLf so as to supply power to the front side of the vehicle body A.

[0059] The power of the high-voltage side housing Ha is supplied to the air conditioner 20 via the high-voltage output cable 23, and the power from the low-voltage side housing Hb is supplied to the information output device 21 via the low-voltage output cable 26.

[0060] Although not shown in the drawings, control signals are transmitted from the control unit configured as the ECU to the high-pressure control jack portion CJa of the high-pressure housing Ha and the low-pressure control jack portion CJb of the low-pressure housing Hb, as described above.

[0061] Thus, in the first embodiment, it is possible to travel in a form in which the rear wheels 2 are driven by the vehicle drive device D disposed at the rear of the vehicle body A. Further, by disposing the high-pressure housing Ha and the low-pressure housing Hb removed from the vehicle drive device D at the front portion (front portion of the cabin) of the vehicle body A, a power supply system that supplies power of a required voltage to each of the air-conditioning device 20 and the information output device 21 is configured without performing voltage conversion by the vehicle drive device D.

[0062] In the configuration of this first embodiment, it is not necessary to use a long cable to supply the power whose voltage has been reduced by voltage conversion in the vehicle drive device D from the vehicle drive device D at the rear of the vehicle body A to the front of the vehicle body A. By removing the high-pressure housing Ha and the low-pressure housing Hb from the vehicle drive device D, the weight of the vehicle drive device D can be reduced, and the weight balance in the front-rear direction of the vehicle body A can also be improved.

[0063] [Modification Example of the First Embodiment] As shown in FIG. 6, a modification example of the first embodiment includes a battery B configured as a secondary battery at the center of a vehicle body A including front wheels 1 and rear wheels 2, a vehicle drive device D (power conversion device DX) is disposed at the rear of the vehicle body A, an air-conditioning device 20 is disposed at the front portion (front portion of the cabin) of the vehicle body A, and an information output device 21 is disposed at the rear of the vehicle body A. Such an arrangement corresponds to the specifications. In this modification example, components common to the first embodiment are denoted by the same reference numerals as those in the first embodiment.

[0064] In this modification example, the vehicle drive device D (power conversion device DX) is configured to be detachably provided with the high-pressure housing Ha with respect to the main housing Hm, and similar to the first embodiment, the high-pressure housing Ha removed from the main housing Hm is provided at the front position of the vehicle body A.

[0065] As a result, power is supplied from the front end of the battery B to the high-voltage side housing Ha via the front power line PLf, and the power converted by this high-voltage side housing Ha is supplied to the air-conditioning equipment 20 via the high-voltage output cable 23. Also, the power converted by the low-voltage side housing Hb is supplied to the information output device 21 from the rear position of the vehicle body A.

[0066] In this modification, the configuration is not limited to one in which the low-voltage side housing Hb is detachably provided with respect to the main housing Hm of the vehicle drive device D, and a configuration in which the low-voltage conversion board 25 is provided inside the vehicle drive device D without using the low-voltage side housing Hb may also be acceptable.

[0067] In addition, when using a vehicle drive device D in which the low-voltage side housing Hb cannot be separated from the main housing Hm, a power supply system is configured to supply the power converted to 12V by the low-voltage conversion board 25 of the main housing Hm to the information output device 21.

[0068] This modification of the first embodiment corresponds to a specification in which the air-conditioning equipment 20 is arranged at the front part (front part of the cabin) of the vehicle body A and the information output device 21 is arranged at the rear part of the vehicle body A. However, for example, it is also conceivable that the information output device 21 is arranged at the front part (front part of the cabin) of the vehicle body A and the air-conditioning equipment 20 is arranged at the rear part of the vehicle body A, which is a reverse arrangement configuration.

[0069] In a configuration with such a reverse arrangement, the high-voltage side housing Ha is arranged at the rear part of the vehicle body A, the low-voltage side housing Hb is arranged at the front part of the vehicle body A, and by configuring the power system according to the modification of the first embodiment described above, it becomes possible to meet the specification.

[0070] 〔Second Embodiment〕 As shown in Fig. 7, in this second embodiment, a battery B configured as a secondary battery is provided at the center of a vehicle body A equipped with a front wheel 1 and a rear wheel 2. Vehicle drive devices D (power conversion devices DX) are arranged at the front and rear parts of the vehicle body A, and an air conditioner 20 and an information output device 21 are arranged at the front part (the front part of the cabin) of the vehicle body A. Such an arrangement corresponds to the specifications. In this second embodiment, components common to the first embodiment are denoted by the same reference numerals as those in the first embodiment.

[0071] With such a configuration in which the vehicle drive devices D (power conversion devices DX) are arranged at two locations on the vehicle body A, the front vehicle drive device D drives the front wheel 1, and the rear vehicle drive device D drives the rear wheel 2. Each vehicle drive device D includes a high-voltage side housing Ha (second housing) and a low-voltage side housing Hb (second housing) that are detachably attached to a main housing Hm (first housing).

[0072] In this second embodiment, in a state where the high-voltage side housing Ha and the low-voltage side housing Hb are provided in the front vehicle drive device D, power is supplied from the high-voltage side housing Ha to the air conditioner 20 via a high-voltage output cable 23, and power is supplied from the low-voltage side housing Hb to the information output device 21 via a low-voltage output cable 26, thus configuring the power supply system.

[0073] Also, in this second embodiment, by maintaining the state in which the high-voltage side housing Ha and the low-voltage side housing Hb are removed from the rear vehicle drive device D, the weight of the rear vehicle drive device D is reduced, and weight reduction of the vehicle body A is achieved.

[0074] 〔Third Embodiment〕 As shown in Fig. 8, a battery B configured as a secondary battery is provided at the center of a vehicle body A equipped with a front wheel 1 and a rear wheel 2. A vehicle drive device D (power conversion device DX) is arranged at the front part of the vehicle body A, an information output device 21 is arranged at the front part of the vehicle body A (front part of the cabin), and an air conditioner 20 is arranged at the rear part of the vehicle body A. Such an arrangement corresponds to the specifications. In addition, in this third embodiment, components common to the first embodiment are denoted by the same reference numerals as those in the first embodiment.

[0075] The vehicle drive device D (power conversion device DX) arranged at the front part of the vehicle body A in this way functions to transmit driving force to the front wheel 1, and includes a high-voltage side housing Ha (second housing) and a low-voltage side housing Hb (second housing) that are detachably attached to the main housing Hm (first housing).

[0076] In this third embodiment, the removed high-voltage side housing Ha from the vehicle drive device D is arranged at the rear part of the vehicle body, the power from the battery B is converted by the high-voltage side housing Ha, and is supplied to the air conditioner 20 from the high-voltage side housing Ha via a high-voltage output cable 23.

[0077] Also, the power converted by the low-voltage side housing Hb of the vehicle drive device D is supplied to the information output device 21 via a low-voltage output cable 26.

[0078] In this configuration, since it is possible to arrange the relatively heavy air conditioner 20 at the rear part of the vehicle body A, it is possible to improve the weight balance in the front-rear direction of the vehicle body A.

[0079] 〔Operation and Effect of the Embodiment〕 As described above, the main housing Hm (first housing) of the vehicle drive device D (power conversion device DX) is provided with a detachably attached high-voltage side housing Ha (second housing) and a low-voltage side housing Hb (second housing). The high-voltage side housing Ha and the low-voltage side housing Hb house voltage conversion circuits that convert the power from the battery B into different voltages.

[0080] Therefore, by attaching or removing the second housing required according to the specifications of the vehicle body A to / from the main housing Hm, it is possible to use a vehicle drive device D having a common configuration even for different specifications without changing the basic configuration of the vehicle drive device D (power conversion device DX), and there is no need to use vehicle drive devices D with different designs for each specification.

[0081] Also, for example, in a specification where the vehicle drive device D is arranged at the rear position of the vehicle body A and the air conditioner 20 is arranged at the front position of the vehicle body A, the relative distance between the positions of the air conditioner 20 and the information output device 21 provided in the cabin and the vehicle drive device D may increase.

[0082] Even in such a specification, by separating the second housing (in the embodiment, the high-voltage side housing Ha) from the vehicle drive device D and arranging it at the front position of the vehicle body A, the power supplied from the front end position of the battery B can be supplied to the second housing, and the voltage can be converted in this second housing and supplied to the air conditioner 20. As a result, there is no need to arrange a power cable between the vehicle drive device D and the air conditioner 20, and the weight balance in the front-rear direction of the vehicle body A is also improved.

[0083] By exposing a part of the cooling water flow path L1 through which the cooling water of the cooling circuit C provided in the vehicle drive device D flows as the high-voltage side cooling plate L1a and the low-voltage side cooling plate L1b at the detachable part 7, when the high-voltage side housing Ha (second housing) and the low-voltage side housing Hb (second housing) are attached to and used with the vehicle drive device D, the heat generated by power conversion can be taken away by the cooling water, and the temperature rise can be suppressed.

[0084] 〔Alternative Embodiment〕 The present invention may be configured as follows in addition to the above-described embodiments (components having the same functions as those in the embodiments are given the same numbers and reference signs as those in the embodiments).

[0085] (a) A detachable part 7 is formed at three or more locations on the main housing Hm (the first housing), and a plurality of second housings that are detachable with respect to these detachable parts 7 are provided. By accommodating voltage conversion circuits with different output voltages in the plurality of second housings, it is possible to supply power to devices with different power supply voltages.

[0086] Also, with the configuration of this alternative embodiment (a), by removing three or more second housings according to the specifications and arranging them at appropriate positions on the vehicle body A, it is possible to cope with various specifications.

[0087] (b) Configure so that a plurality of types of second housings that convert to different voltages can be attached and detached to the detachable part 7 formed on the main housing Hm (the first housing). By configuring in this way, it is possible to use power of a plurality of voltages without increasing the number of detachable parts 7.

[0088] (c) Configure the power conversion device DX as an individual device from the vehicle drive device D. For example, by configuring the power conversion device DX for exclusive use in power conversion, the power conversion device DX can be provided at an arbitrary position on the vehicle body A, and it is also possible to cope with various specifications.

[0089] In addition, the configurations disclosed in the above embodiments (including alternative embodiments, the same applies hereinafter) can be applied in combination with the configurations disclosed in other embodiments as long as there is no contradiction. Also, the embodiments disclosed in this specification are examples, and the embodiments of the present invention are not limited to this, and can be appropriately modified within the scope not departing from the object of the present invention.

[0090] In the above-described embodiments, the following configurations are recalled. (1) A power conversion device including a first housing Hm that at least houses an inverter 6 that is supplied with high-voltage power from a battery B to drive a traveling motor 4, and a second housing (high-voltage side housing Ha) that houses a voltage conversion unit (high-voltage conversion substrate 22) that converts the high-voltage power of the battery B into low-voltage power. A detachable portion 7 for detachably supporting the second housing (high-voltage side housing Ha) is formed in the first housing Hm.

[0091] According to this, by attaching the second housing (high-voltage side housing Ha) to the detachable portion 7 formed in the first housing Hm, the power conversion device DX can be used in a form in which the high-voltage power of the battery B is converted into low-voltage power in the voltage conversion unit (high-voltage conversion substrate 22) of the second housing (high-voltage side housing Ha) and supplied to an electrical device (air conditioning device 20). Also, for example, separating the second housing (high-voltage side housing Ha) from the first housing Hm, arranging it at a position separated from the first housing Hm, and converting the power from the battery B into low-voltage power in the voltage conversion unit (high-voltage conversion substrate 22) of the second housing (high-voltage side housing Ha), it is possible to supply the power of the voltage required for the electrical device (air conditioning device 20) without arranging a power cable between the first housing Hm. Further, when the electrical device (air conditioning device 20) that requires the power of the voltage converted by the voltage conversion unit (high-voltage conversion substrate 22) of the second housing (high-voltage side housing Ha) is not provided, it is also possible to remove the second housing (high-voltage side housing Ha) from the first housing Hm. Thus, the second housing Ha can be made to correspond to the specifications of the vehicle such as the positional relationship with the electrical device (air conditioning device 20) and the presence or absence of the use of the power of the required voltage.

[0092] (2) In the power conversion device DX of (1), it is preferable that the first housing Hm further houses a traveling motor 4 and a gear reduction mechanism 5 that reduces the driving force of the traveling motor 4.

[0093] According to this, a detachable part 7 is formed in the first housing Hm of the vehicle drive device D including the driving motor 4 and the gear reduction mechanism 5 for deceleration, and the second housing Hb can be attached to and detached from this detachable part 7. As a result, since the power conversion device DX is integrated with the vehicle drive device D, routing of piping can be prevented and compactification can be achieved.

[0094] (3) In the power conversion device DX of (1) or (2), it is preferable to include a connection part K that supplies the high-voltage power supplied from the first housing Hm to the voltage conversion part (high-voltage conversion substrate 22) of the second housing (high-voltage side housing Ha) when an electrical connection state is reached with the second housing (high-voltage side housing Ha) attached to the first housing Hm.

[0095] According to this, when the second housing (high-voltage side housing Ha) is attached to the first housing Hm, the trouble of artificially connecting the power cable can be saved.

[0096] (4) In any one of the power conversion devices DX of (1) to (3), it is preferable that a cooling plate (high-voltage side cooling plate L1a) for cooling the inverter 6 by supplying a cooling fluid is fixed in an exposed state to the notch surface (high-voltage side fitting wall 7aw) where the detachable part 7 is formed in the first housing.

[0097] According to this, when the second housing (high-voltage side housing Ha) is attached to the first housing Hm, the second housing (high-voltage side housing Ha) is brought close to the cooling plate (high-voltage side cooling plate L1a), enabling cooling of the voltage conversion part (high-voltage conversion substrate 22).

Industrial Applicability

[0098] The present invention can be used for a power conversion device.

Explanation of Signs

[0099] 4: Travel motor, 5: Gear reduction mechanism, 6: Inverter, 7: Detachable part, 7aw: High-voltage side fitting wall (notch surface), 7bw: Low-voltage side fitting wall (notch surface), 22: High-voltage conversion substrate (voltage conversion part), 25: Low-voltage conversion substrate (voltage conversion part), C: Cooling circuit, DX: Power conversion device, Hm: Main housing (first housing), Ha: High-voltage side housing (second housing), Hb: Low-voltage side housing (second housing), K: Connection part, L1a: High-voltage side cooling plate (cooling plate), L1b: Low-voltage side cooling plate (cooling plate)

Claims

1. A first housing that houses at least an inverter that is supplied with high-voltage power from a battery and drives a traveling motor; A second housing that houses a voltage conversion unit that converts the high-voltage power of the battery into low-voltage power, the power conversion device comprising: The first housing is formed with a detachable portion that detachably supports the second housing.

2. The power conversion device according to claim 1, wherein the first housing further houses the traveling motor and a gear reduction mechanism that reduces the driving force of the traveling motor.

3. The power conversion device according to claim 2, further comprising a connection portion that supplies the high-voltage power supplied from the first housing to the voltage conversion unit of the second housing when an electrical connection state is reached with the second housing mounted on the first housing.

4. The power conversion device according to any one of claims 1 to 3, wherein a cooling plate that cools the inverter by supplying a cooling fluid is fixed in an exposed state on a cut surface of the first housing where the detachable portion is formed.

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