Power conversion device

Abstract

The power conversion device comprises: a power conversion circuit that converts input power into direct current power or alternating current power; a base member made of resin on which the power conversion circuit is placed; a cover member that houses the power conversion circuit between the cover member and the base member; a refrigerant flow path that is provided inside the base member so that a refrigerant for cooling the power conversion circuit flows; and a temperature sensor that is provided on the base member and detects the temperature of the refrigerant flowing in the refrigerant flow path. The temperature sensor comprises a conductive member including at least a thermistor, and at least a portion of the conductive member is surrounded by a resin wall formed of an insulating material.

Description

Technical Field

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

[0002] JP5471685B discloses a structure in which, in a power conversion device that uses a refrigerant to cool a semiconductor module, a temperature sensor is provided in a cooling pipe through which the refrigerant flows to constantly monitor the temperature of the refrigerant in order to control the temperature of the semiconductor module to be cooled. Summary of the invention

[0003] Here, in order to accurately control the temperature of the semiconductor module, which is the object to be cooled, there is a requirement to place the temperature sensor as close to the semiconductor module as possible. In order to meet such a requirement, it is conceivable to arrange the temperature sensor inside the power conversion device. However, when the temperature sensor is arranged inside the power conversion device, it is necessary to ensure a prescribed insulation distance between the electronic components constituting the power conversion device and the temperature sensor, so there is a problem of increasing the size of the power conversion device.

[0004] An object of the present invention is to provide a technology capable of ensuring insulation between electronic components constituting a power conversion device and the temperature sensor without increasing the size of the power conversion device when the temperature sensor is disposed inside the power conversion device.

[0005] A power conversion device according to one embodiment of the present invention comprises: a power conversion circuit that converts input power into DC power or AC power; a base member made of resin on which the power conversion circuit is placed; a cover member that houses the power conversion circuit between the cover member and the base member; a coolant flow path that is provided inside the base member and allows coolant for cooling the power conversion circuit to flow; and a temperature sensor that is provided on the base member and detects the temperature of the coolant flowing in the coolant flow path. The temperature sensor comprises a conductive member that at least includes a thermistor, and at least a portion of the conductive member is surrounded by a resin wall formed of an insulating material.

[0006] Below and attached Figure 1 The embodiments of the present invention will now be described in detail. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a diagram for explaining the power conversion device according to the first embodiment.

[0008] Figure 2 yes Figure 1 AA section view.

[0009] Figure 3 is a diagram illustrating a sub-section.

[0010] Figure 4 It is a diagram for explaining Modification 1 of the power conversion device according to the first embodiment.

[0011] Figure 5 It is a diagram for explaining the joining method of the metal cover and the metal plate in Modification Example 1.

[0012] Figure 6 It is a diagram for explaining Modification 2 of the power conversion device according to the first embodiment.

[0013] Figure 7 It is a diagram for explaining the power conversion device according to the second embodiment.

[0014] Figure 8 It is a diagram for explaining the power conversion device according to the third embodiment.

[0015] Fig. 9 It is a perspective view showing a current power conversion device.

[0016] Fig.10 This is a diagram for explaining a conventional power conversion device.

[0017] Fig.11 is a diagram illustrating a current temperature sensor. DETAILED DESCRIPTION

[0018] <First embodiment>

[0019] Figure 1 It is a schematic configuration diagram for explaining the power conversion device 100 according to the first embodiment.

[0020] The power conversion device 100 includes a power module 2, a control substrate 3, a smoothing capacitor 4, a base member 5 made of resin, a metal cover 7, and a temperature sensor 8. In addition, the base member 5 has a refrigerant flow path 6 through which a refrigerant can flow. The power conversion device 100 is mounted on a vehicle having a motor, for example, and functions as a power supply unit for the motor, that is, a vehicle-mounted power converter.

[0021] The power module 2, the control substrate 3, and the smoothing capacitor 4 are mainly electronic components required for converting input power into specified power for output, and the circuit composed of the above electronic components is, for example, an inverter. Hereinafter, the above electronic components are collectively referred to as a power conversion circuit 1. The power conversion circuit 1 is electrically connected to an external power supply via an electrical terminal (input terminal) not shown in the figure, and is connected to a motor not shown in the figure via other electrical terminals (output terminals). Moreover, the power conversion circuit 1 converts the DC power supplied from the above external power supply into AC power and supplies it to the motor, or converts the AC power supplied from the motor into DC power and supplies it to the external power supply. In addition, at least the power module 2 among the various electronic components possessed by the power conversion circuit 1 of the present embodiment is mounted on one surface ( Figure 1 The upper surface in the present embodiment shown in FIG. 1 is fixed to the base member 5 by fixing bolts or the like not shown in the figure.

[0022] The base member 5 functions as a cooler for cooling the power conversion circuit 1. The base member 5 is made of an insulating material. The base member 5 of this embodiment is an electrically insulating resin, and in consideration of strength, for example, polyphenylene sulfide (PPS) resin, polyphthalamide (PPA) resin, or the like is used.

[0023] The base member 5 has a coolant flow path (coolant piping portion) 6 through which a coolant (e.g., cooling water) can flow. In the present embodiment, for example, a long life coolant (LLC) coolant is used as the cooling water flowing through the coolant flow path 6. The base member 5 performs heat exchange between the power conversion circuit 1 (particularly, the power module 2) mounted on one surface and the cooling water flowing through the coolant flow path 6 formed inside, thereby cooling the power conversion circuit 1.

[0024] The temperature sensor (water temperature sensor) 8 is configured to detect (measure) the temperature of the refrigerant flowing in the refrigerant flow path 6 inside the power conversion device 100. In addition, the power conversion device 100 controls the temperature of the cooling water based on the detection value of the temperature sensor 8 so that the temperature of the power conversion circuit 1 converges to an appropriate temperature range. Figure 2 , 3 The details of the temperature sensor 8 according to this embodiment will be described later.

[0025] The metal cover 7 functions as a housing for housing the power conversion circuit 1 and the temperature sensor 8 disposed between the metal cover 7 and the base member 5 in the power conversion device 100. The metal cover 7 of the present embodiment is formed of a metal such as aluminum, for example. The metal cover 7 has a recessed portion, and is fixed to the upper surface of the base member 5 using fixing bolts (not shown) in such a manner that the power conversion circuit 1 is housed in the recessed portion. Thus, in the power conversion device 100 of the present embodiment, the metal cover 7 and the base member 5 function as a housing for housing the power conversion circuit 1. In addition, the base member 5 has not only the above-mentioned cooling function, but also has a function as a part of the housing for housing the power conversion circuit 1.

[0026] Here, refer to Figures 9 to 11 Problems faced by conventional power conversion devices will be described.

[0027] Fig. 9 1 is a perspective view showing an example of a current structure of an electric power conversion device applied to an electric vehicle. The electric power conversion device shown in the figure has a water pipe 50, a weak current connector 51, an external weak current wiring 52, and a temperature sensor 53. The water pipe 50 is a pipe for introducing a refrigerant from the outside or discharging the refrigerant to the outside with respect to a refrigerant flow path formed inside the electric power conversion device.

[0028] As shown in the figure, in the current example involving the power conversion device, the temperature sensor 53 is arranged on the water pipe 50 outside the power conversion device to avoid the risk of water leakage inside the power conversion device, and is configured to directly detect the temperature of the refrigerant circulating inside the water pipe 50. The data signal related to the detected temperature (water temperature) is transmitted to the control substrate not shown in the figure configured inside the power conversion device via the external weak current wiring 52 and the weak current connector 51. In this case, the distance between the cooling object built into the power conversion device, that is, the power conversion circuit and the temperature sensor 53 becomes longer, so there is a problem of reduced accuracy of the temperature control of the power conversion circuit performed based on the cooling water temperature detected by the temperature sensor 53.

[0029] Furthermore, when the temperature sensor 53 is disposed inside the power conversion device, the following problem also occurs.

[0030] Fig.10It is a diagram showing an example of the current structure involved in the interior of the power conversion device, and is a diagram illustrating the positional relationship between the temperature sensor 53 and the electronic component (power conversion circuit 1) built into the power conversion device. In the current example shown in this figure, the power conversion device accommodates the power conversion circuit 1 composed of a power module 2, a control substrate 3, and a strong electric component connection portion 20 between a metal base member 54 and a metal cover 7 not shown. The base member 54 is provided with a refrigerant flow path for circulating a refrigerant therein, and the refrigerant is used to cool the power conversion circuit 1. Moreover, the temperature sensor 53 is configured as shown in the figure to detect the temperature of the refrigerant flowing in the refrigerant flow path inside the power conversion device.

[0031] Here, using Fig.11 The structure of the current temperature sensor 53 will be described. Fig.11 1 is a schematic diagram showing an example of the structure of a current temperature sensor (temperature sensor 53 ). Fig.11 (a) is a perspective view showing the appearance of the temperature sensor 53. Fig.11 (b) is a diagram for explaining the internal structure of the temperature sensor 53. Fig.11 As shown, the temperature sensor 53 is composed of a male connector part 12 and a metal shell part 13. The metal shell part 13 is made of brass, for example. Moreover, a thermistor 17 is arranged in the internal space near the end (front end) of the front end side (opposite side of the male connector part 12) of the metal shell part 13. The thermistor 17 is an electronic component whose resistance value changes due to temperature changes. In addition, a thermal conductive material (packaging material) 18 composed of epoxy resin material or grease is filled in the internal space on the front end side of the metal shell part 13 to surround the thermistor 17. Moreover, the temperature sensor 53 is configured so that at least its front end is arranged in the refrigerant flow path and the temperature of the refrigerant circulating in the refrigerant flow path can be detected according to the change of the resistance value of the thermistor 17. In addition, a signal related to the temperature change of the thermistor 17 is transmitted to the control substrate 3 via the female connector 16.

[0032] like Fig.10 As shown, in the present example, the temperature sensor 53 is arranged near the power conversion circuit inside the power conversion device. However, the present temperature sensor 53 has a metal shell portion 13 made of a conductor such as brass, and therefore needs to be set at a predetermined distance between components required to ensure insulation from the conductive components constituting the power conversion circuit 1. Fig.10, when the current temperature sensor 53 is arranged inside the power conversion device, it is necessary to set a predetermined distance 19 between components required for ensuring insulation between the component (in this example, the strong electric element connection part 20) arranged at the position closest to the temperature sensor 53 among the conductive components of the power conversion circuit 1. As a result, if the temperature sensor 53 is currently arranged inside the power conversion device, there is a problem that the size of the power conversion device becomes larger according to the predetermined distance 19 between components.

[0033] The above are the problems of the current power conversion device. With respect to the current power conversion device as described above, the power conversion device 100 according to the present invention can solve the above problems. Figure 2 etc. describe the details of the power conversion device 100 according to the first embodiment of the present invention.

[0034] Figure 2 yes Figure 1 AA cross-sectional view of FIG. 1 , which is a diagram for explaining the details of the temperature sensor 8 included in the power conversion device 100 according to the first embodiment.

[0035] As shown in the figure, the temperature sensor 8 is composed of a sensor housing portion 23 and a sub-portion 29 housed therein. In addition, the sensor housing portion 23 is composed of a male connector portion 12, a main body portion 11, and a protruding portion 30 that protrudes into the refrigerant flow path 6. In addition, as shown in the figure, the sensor housing portion 23 constituting the temperature sensor 8 of the present embodiment is formed integrally with the resin base member 5.

[0036] Figure 3 2 is a schematic structural diagram for explaining an example of the structure of the sub-section 29. The sub-section 29 is configured to include the thermistor 17, the lead wire 24, the signal terminal 25, and the resin cover 28. The thermistor 17, the lead wire 24, and the signal terminal 25 are conductive members.

[0037] The thermistor 17 is an electronic component whose resistance value changes according to temperature. A signal related to the resistance value of the thermistor 17 that changes according to the temperature of the detection object is transmitted to the control substrate 3 via the lead wire 24, the signal terminal 25, and the female connector 16 described later. In addition, the resin cover 28 is configured to hold the signal terminal 25 electrically connected to the thermistor 17 and the lead wire 24, and is held at a predetermined position inside the sensor housing 23.

[0038] Back to Figure 2The description is continued. As described above, the temperature sensor 8 is configured to include a sensor housing portion 23 and a sub-portion 29. As shown in the figure, the sensor housing portion 23 (male connector portion 12, main body portion 11, and protrusion 30) is integrally configured with a resin base member 5. That is, in the power conversion device 100 of the present embodiment, the conductive member related to the sub-portion 29 of the temperature sensor 8 is surrounded by a resin wall formed of an insulating material. The resin wall is a part of the temperature sensor 8 and is configured as the sensor housing portion 23 that accommodates the sub-portion 29.

[0039] The sensor housing portion 23 of the present embodiment is configured by forming a base member 5 and a metal cover 7 (see Figure 1 ) includes a cylindrical (cylindrical) portion formed protruding from one surface of the base member 5 (the same surface as the surface on which the power module 2 is mounted in this embodiment). The male connector portion 12 is a cylindrical portion formed continuously with the main body portion 11, and is formed to be able to be mated with the female connector 16. The protruding portion 30 is a cylindrical portion formed protruding in the refrigerant flow path 6 formed inside the base member 5, and a space is formed therein. The space is formed to be continuous with the male connector portion 12 formed in a cylindrical shape and the internal space of the main body portion 11.

[0040] Furthermore, the temperature sensor 8 is constructed by installing the sub-portion 29 in a continuous space inside the male connector portion 12 , the main body portion 11 , and the protruding portion 30 constituting the sensor housing portion 23 .

[0041] The sub-portion 29 is preferably installed so that the thermistor 17 is located in the internal space of the protrusion 30, and the signal terminal 25 is located in the internal space of the male connector portion 12. As shown in the figure, the sub-portion 29 of the present embodiment is installed so that the thermistor 17 is located in the internal space of the protrusion 30, a part of the signal terminal 25, a part of the resin cover 28, and the lead 24 are located in the internal space of the main body 11, and a part of the signal terminal 25 on the side connected to the female connector 16 and a part of the resin cover 28 are located in the internal space of the male connector portion 12. Thus, the temperature sensor 8 of the present embodiment is formed integrally with the base member 5, and the front end portion (protrusion 30) accommodating the thermistor 17 is arranged in the refrigerant flow path 6 through which the refrigerant, which is the object of temperature detection, flows, and the signal related to the measured temperature can be transmitted to the control substrate 3 via the female connector 16 engaged with the male connector portion 12.

[0042] In addition, the boundary lines of the male connector part 12, the main body part 11, and the protruding part 30 of the sensor housing part 23 are not particularly limited. In this embodiment, as an example, the part located at one end side of the sensor housing part 23 and having a part that can be fitted with the female connector 16 is set as the male connector part 12, the part located at the other end side of the sensor housing part 23 and having a part protruding toward the coolant flow path 6 is set as the protruding part 30, and the part located between the male connector part 12 and the protruding part 30 and at least rising from the base member 5 in the same plane as the surface of the power module 2 on which the base member 5 is placed is called the main body 11.

[0043] In addition, the internal space of the main body 11 and the protrusion 30, in other words, the space inside the temperature sensor 8 closer to the protrusion side (coolant flow path side) than the resin cover 28, is filled with a heat conductive material 18. The heat conductive material 18 is a material (packaging material) having heat conductivity such as an epoxy resin material or grease. Thus, with respect to the thermistor 17, when the protrusion 30 and the cooling water are in contact in the coolant flow path 6, the heat of the cooling water becomes easier to be conducted through the heat conductive material 18, so that the temperature of the coolant can be detected more appropriately.

[0044] In addition, the shape of the protrusion 30 can also be appropriately set in consideration of strength, etc. However, if the strength is satisfied as a premise, it is preferably formed as thin as possible so that the temperature of the cooling water can be accurately transmitted through the thermistor 17. In addition, the protrusion 30 is preferably formed so that the cooling water in the coolant flow path 6 flows more without resistance. For example, the protrusion 30 can also be configured to be formed in an elliptical shape, and its major axis is consistent with the direction of the cooling water flow.

[0045] Through the structure described above, the temperature sensor 8 can detect the temperature of the cooling water flowing in the refrigerant flow path 6 inside the power conversion device 100 without the risk of the cooling water flowing in the refrigerant flow path 6 intruding into the interior of the power conversion device 100 (the space between the base component 5 and the metal cover 7).

[0046] In addition, the conductive components of the temperature sensor 8, including the thermistor 17 and the signal terminal 25, are surrounded by the sensor housing 23 made of an insulating resin material, so that the predetermined distance 19 between components (see Fig.10) to ensure insulation between the electronic components (in the figure, in particular, the strong electric component connection part 20 of the power module 2) arranged inside the power conversion device 100 and the temperature sensor 8. As a result, inside the power conversion device 100, the distance 19 between components for ensuring insulation is not required, and the temperature sensor 8 can be arranged closer to the power conversion circuit 1 including the power module 2, etc., which can improve the freedom of the internal layout of the power conversion device 100 and make the power conversion device 100 miniaturized. In addition, the temperature sensor 8 can be arranged near the power conversion circuit 1, which is the temperature control object, thereby improving the accuracy of the temperature control of the power conversion circuit 1 performed based on the cooling water temperature detected by the temperature sensor 8. In addition, by arranging the temperature sensor 8 inside the power conversion device 100, the temperature sensor 8 is not required. Fig. 9 The external weak-current wiring 52 shown can therefore also achieve a reduction in the number of signal pins of the weak-current connector 51 and a reduction in cost.

[0047] The above is the details of the power conversion device 100 according to the first embodiment. Next, a modification of the power conversion device 100 according to the first embodiment will be described.

[0048] (Variant 1)

[0049] Figure 4 1 is a diagram for explaining a first modification of the power conversion device 100. The power conversion device 100 described above includes a base member 5 having a coolant flow path 6 as a base portion of the power conversion device 100, but the power conversion device 100 is not limited to such a structure. Figure 4 The modified example 1 shown is configured in the manner described above.

[0050] exist Figure 4 In the modification 1 shown, a metal plate 31 made of a metal such as aluminum is arranged outside the base member 5. The metal plate 31 is assembled with the metal cover 7 to form a part of the outer casing (housing) of the power conversion device 100 of the modification 1. The assembly method of the metal plate 31 and the metal cover 7 is shown in FIG. Figure 5 For explanation.

[0051] Figure 5 This is a diagram for explaining an example of a method of assembling the metal plate 31 and the metal cover 7 . Figure 5 The portion shown is equivalent to Figure 4 The double-dotted circle part.

[0052] The metal plate 31 and the metal cover 7 of the modification 1 are fixed by bolts 33. At this time, as shown in the figure, the bolts 33 are inserted from the outside of the metal plate 31, and the metal collar (gasket) portion 34 provided at the end of the base member 5 is penetrated and screwed to the metal cover 7. As a result, the base member 5 is fixed between the metal plate 31 and the metal cover 7, and the power conversion circuit 1 such as the power module 2 mounted on the base member 5 is accommodated between the metal plate 31 and the metal cover 7. By configuring the power conversion device 100 in this way, the power conversion device 100 can ensure the EMC shielding performance for the power conversion circuit 1 accommodated inside through the metal shell composed of the metal plate 31 and the metal cover 7. In addition, between the base member 5 and the metal cover 7, a rubber material such as nitrile rubber (NBR), ethylene propylene diene monomer rubber (EPDM), or a liquid sealant (FIPG) is used as a sealing member 32, so that the shell sealing performance of the power conversion device 100 can also be ensured.

[0053] (Variant 2)

[0054] Figure 6 1 is a diagram for explaining a second modification of the power conversion device 100. In the above-mentioned power conversion device 100, a structure in which the base member 5 is arranged on the lower side of the power conversion device 100 as a base portion is disclosed, but the power conversion device 100 is not limited to such a structure. Figure 6 The method is configured in the manner of the modified example 2 shown in .

[0055] That is, the direction (up, down, left, and right) in which the power conversion device 100 is mounted is not particularly limited. Figure 6 As shown, the base member 5 may be arranged on the upper side. In this way, when the power conversion device 100 is applied to an electric vehicle, for example, it can be freely arranged according to the desired layout of the electric vehicle.

[0056] As described above, the power conversion device 100 of the first embodiment includes: a power conversion circuit 1 that converts input power into DC power or AC power; a base member 5 made of resin, on which the power conversion circuit 1 is placed; a cover 7 (cover member) that accommodates the power conversion circuit 1 between the cover member and the base member 5; a refrigerant flow path 6 that is provided inside the base member 5 and allows the refrigerant used to cool the power conversion circuit 1 to flow; and a temperature sensor 8 that is provided on the base member 5 and detects the temperature of the refrigerant flowing in the refrigerant flow path 6. The temperature sensor 8 includes a conductive component including at least a thermistor 17, and at least a portion of the conductive component is surrounded by a resin wall formed of an insulating material. Thus, the conductive component of the temperature sensor 8 is surrounded by a resin wall formed of a resin made of an insulating material, and therefore, it is possible to not provide a predetermined distance 19 between components (refer to Fig.10), and ensure the insulation between the electronic components (in the above description, especially the strong electric component connection part 20 of the power module 2) arranged inside the power conversion device 100 and the temperature sensor 8. As a result, the temperature sensor 8 can be arranged inside the power conversion device 100 without increasing the size of the power conversion device 100.

[0057] In addition, according to the power conversion device 100 of the first embodiment, the resin wall is a part of the temperature sensor 8, and is constituted as a sensor housing portion 23 (housing portion) that accommodates conductive components (signal terminals 25, leads 24, and thermistor 17), and the sensor housing portion 23 is formed integrally with the resin base member 5. Thus, in the sensor housing portion 23 of the temperature sensor 8, in particular, the portion (protrusion 30) that protrudes into the coolant flow path 6 is integrally constituted with the base member 5, thereby eliminating the risk of cooling water flowing in the coolant flow path 6 invading the interior of the power conversion device 100. In addition, the conductive components of the temperature sensor 8 are reliably accommodated in the sensor housing portion 23 composed of the resin of the insulating material, so that the prescribed distance 19 between components is not required (see Fig.10 ) and ensure the insulation between the electronic components configured inside the power conversion device 100 and the temperature sensor 8, so that the configuration position of the temperature sensor 8 can be closer to the position of the power module 2.

[0058] In addition, according to the power conversion device 100 of the first embodiment, the sensor housing portion 23 has a protruding portion 30 protruding into the coolant flow path 6, and the thermistor 17 is accommodated in the protruding portion 30. As a result, the distance between the thermistor 17 of the temperature sensor 8 and the cooling water flowing in the coolant flow path 6 can be made closer, and the contact area between the cooling water and the protruding portion 30 can be increased, so that the temperature of the cooling water can be detected with higher accuracy.

[0059] <Second embodiment>

[0060] A power conversion device 200 according to the second embodiment will be described.

[0061] Figure 7 FIG. 2 is a diagram for explaining a configuration example of a power conversion device 200 according to a second embodiment, and is a diagram for explaining a configuration example of a power conversion device 200 according to a second embodiment. Figure 1 The power conversion device 200 of the present embodiment is characterized by the arrangement of the temperature sensor 8 inside the power conversion device 200. The arrows shown in the figure indicate the flow direction of the cooling water in the refrigerant flow path 6.

[0062] Here, in the cooling medium flow path 6 for cooling the power module 2 accommodated in the power conversion device 200, a heat flow caused by the heat of the power module 2 is generated for the cooling water flowing at the position where the power module 2 is arranged. Figure 7 As shown, for example, in this embodiment, the refrigerant flow path 6 at the position where the power module 2 is configured is provided with heat dissipation fins 27 for the purpose of improving the efficiency of heat exchange between the power module 2 and cooling water, and a heat flow (refer to the wavy arrow) using the power module 2 as a heat source is generated from the heat dissipation fins 27.

[0063] Therefore, the temperature sensor 8 of the second embodiment is arranged on the upstream side of the position where the power module 2 is arranged in the refrigerant flow path 6 where the cooling water for cooling the power module 2 flows. As a result, the temperature sensor 8 can more accurately measure the temperature of the cooling water flowing in the refrigerant flow path 6 without being affected by the heat flow caused by the power module 2, so that the accuracy of the temperature control of the power conversion circuit 1 performed based on the cooling water temperature measured by the temperature sensor 8 can be improved.

[0064] As described above, according to the power conversion device 200 of the second embodiment, the temperature sensor 8 is arranged upstream of the position where the power conversion circuit 1 is arranged in the coolant flow path 6 provided inside the base member 5. As a result, the temperature of the cooling water flowing in the coolant flow path 6, that is, the cooling water not affected by the heat flow caused by the power module 2, can be measured, so the temperature of the cooling water can be measured more accurately, and the accuracy of the temperature control of the power conversion circuit 1 performed based on the cooling water temperature measured by the temperature sensor 8 can be improved.

[0065] <Third Embodiment>

[0066] A power conversion device 300 according to the third embodiment will be described.

[0067] Figure 8 FIG. 2 is a diagram for explaining a configuration example of a power conversion device 300 according to the third embodiment, and is similar to the power conversion device 200. Figure 1 The power conversion device 300 of this embodiment is characterized in that the current temperature sensor 53 (see Fig.10 ) is a temperature sensor for measuring the temperature of cooling water, and has a resin wall 22 that surrounds at least a portion of the temperature sensor 53.

[0068] Specifically, if Figure 8As shown in FIG. 1 , the temperature sensor 53 of the present embodiment is arranged near the power module 2 on the same surface of the base member 5 as the surface on which the power module 2 is mounted. The temperature sensor 53 is configured to be located at the front end of the metal casing portion 13 on the opposite side from the male connector portion 12 and at least at a portion accommodating the thermistor 17 (see FIG. 1 ). Fig.11 (b) The base member 5 is penetrated and protrudes into the coolant flow path 6 .

[0069] In other words, the base member 5 of the present embodiment is configured to have a through hole communicating with the coolant flow path 6 near the position where the power module 2 is placed, and when the temperature sensor 53 is placed on the base member 5, the front end of the metal shell portion 13 of the temperature sensor 53 penetrates the through hole and protrudes into the coolant flow path 6. In addition, the temperature sensor 53 is fixed by screwing the tap portion 14 provided on the metal shell portion 13 into a predetermined position of the base member 5, etc.

[0070] When the temperature sensor 53 is fixed to the base member 5, a sealing performance is ensured by using a sealing material 15. The sealing material 15 is made of a rubber material such as nitrile butadiene rubber (NBR) or ethylene propylene diene monomer rubber (EPDM), or a copper gasket.

[0071] Furthermore, a resin wall 22 integrally formed with the base member 5 is provided around the temperature sensor 53 of the present embodiment. The resin wall 22 is configured to surround at least the periphery of the metal casing portion 13. The height of the resin wall 22 of the present embodiment is set to at least exceed the height of a line (refer to the dotted line in the figure) connecting the highest position of the metal casing portion 13 and the portion of the electronic component of the power conversion circuit 1 that is closest to the metal casing portion 13 (in the present embodiment, the strong electric component connection portion 20 of the power module 2).

[0072] In this way, inside the power conversion device 300, at least the metal shell portion 13 of the temperature sensor 53 is surrounded by the resin wall 22, thereby ensuring the insulation between the electronic components of the power conversion circuit 1 and the temperature sensor 53 without setting a predetermined distance 19 between components (refer to FIG. 19 ). As a result, inside the power conversion device 300, the temperature sensor 53 can be arranged near the power conversion circuit 1 including the power module 2 without requiring the distance 19 between components, thereby improving the accuracy of the temperature control of the power conversion circuit 1 based on the cooling water temperature detected by the temperature sensor 53, and miniaturizing the power conversion device 300 compared to the current situation. In addition, by arranging the temperature sensor 53 inside the power conversion device 300, it is possible to eliminate the need for the temperature sensor 53 to be arranged inside the power conversion device 300. Fig. 9 By eliminating the external weak-current wiring 52 shown in the figure, the number of signal pins of the weak-current connector 53 can be reduced and the cost can be reduced.

[0073] As described above, according to the power conversion device 300 of the third embodiment, the conductive member includes the metal casing portion 13 that accommodates the thermistor 17, and the temperature sensor 53 is configured such that, when placed on the base member 5, a portion of the metal casing portion 13 penetrates the base member 5 and protrudes into the coolant flow path 6. As a result, the metal casing portion 13 of the temperature sensor 53 is surrounded by the resin wall 22 made of the resin of the insulating material, so that the predetermined distance 19 between components can be omitted (see Fig.10 ), and ensure the insulation between the electronic components arranged inside the power conversion device 300 and the temperature sensor 53. As a result, the temperature sensor 53 can be arranged inside the power conversion device 300 without increasing the size of the power conversion device 300, so that the power conversion device 300 can be miniaturized compared with the conventional method.

[0074] The embodiments of the present invention and their variations are described above, but the embodiments and variations are only a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific structures of the embodiments and variations. The present invention is not limited to the embodiments and variations, and various modifications and applications are possible.

[0075] For example, the sensor housing 23 and the resin wall 22 formed integrally with the base member 5 described above do not need to be seamlessly (unjoined) integrally molded with the base member 5. The sensor housing 23 and the resin wall 22 and the base member 5 may be joined by secondary bonding or mechanical joining after being molded separately.

[0076] The shape of the sensor housing 23 and the like is not limited to the shape shown in the drawings, and may be appropriately changed in consideration of strength and the like as long as the above-mentioned technical features are possessed.

Claims

1. A power conversion device, comprising: A power conversion circuit that converts input power into DC power or AC power; A resin base member, which is made of an insulating material and on which the power conversion circuit is mounted; a cover member for housing the power conversion circuit between the cover member and the base member; a cooling medium flow path provided inside the base member so that a cooling medium for cooling the power conversion circuit flows; as well as a temperature sensor disposed on the base member and detecting the temperature of the refrigerant flowing in the refrigerant flow path; The temperature sensor has a conductive component including at least a thermistor, The conductive member is surrounded by a resin wall formed so as to protrude from the same surface of the base member on which the power conversion circuit is placed.

2. The power conversion device according to claim 1, wherein: The resin wall is a part of the temperature sensor and is configured as a housing portion for housing the conductive member. The case portion is formed integrally with the base member made of resin.

3. The power conversion device according to claim 2, wherein: The housing portion has a protruding portion protruding into the refrigerant flow path, The thermistor is accommodated in the protruding portion.

4. The power conversion device according to claim 1, wherein: The conductive component includes a metal housing portion for housing the thermistor. The temperature sensor is configured such that, in a state in which the temperature sensor is placed on the base member, a portion of the metal casing portion penetrates the base member and protrudes into the refrigerant flow path.

5. The power conversion device according to any one of claims 1 to 4, wherein: The temperature sensor is arranged upstream of a position where the power conversion circuit is arranged in the refrigerant flow path provided inside the base member.

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