Spring bodies, spring components, and power conversion devices

Abstract

The present invention provides a spring body, a spring component, and a power conversion device in which fluctuations in restoring force are suppressed. [Solution] The restoring force that presses the switch case included in the power conversion circuit against the case is provided by a spring body 720 that acts on the switch case at the point of application 780a. The spring body has a spring portion 780 having a point of application, a support portion 770 that supports the spring portion, and a connecting portion 760 that is connected to the support portion and connected to the fixing portion 710 by a fixing hole 762a. The creepage distance between the fixing hole and the support portion is longer than the creepage distance between the support portion and the point of application.

Description

Technical Field

[0001] The disclosure described in this specification relates to a spring body, spring parts, and a power conversion device.

Background Art

[0002] Patent Document 1 discloses a pressurizing member that brings a semiconductor module and a cooler into close contact by pressurization. The pressurizing member has a plurality of spring parts that generate a pressing force and a connecting plate part that connects the plurality of spring parts. A pressurization-side engaging part is formed on the connecting plate part.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, the pressurizing member and the plate are arranged side by side. A plate-side engaging part is formed on the plate. The pressurizing member is fixed to the plate by engaging the pressurization-side engaging part and the plate-side engaging part.

[0005] Due to such engagement, there is a possibility that distortion may occur in the pressurizing member. Due to the distortion, there is a possibility that the pressing force (restoring force) acting on the semiconductor module and the cooler from the spring part may fluctuate.

[0006] An object of the present disclosure is to provide a spring body, spring parts, and a power conversion device in which fluctuations in the restoring force are suppressed.

Means for Solving the Problems

[0007] The spring body of the disclosed aspect is A spring body acting on the electrical components at the point of application (780a) provides a restoring force that presses the electrical components (521, 550) included in the power conversion circuit (500) against the cooler (600), A spring portion (780) having a point of application, A support part (770) that supports the spring part, It has a connecting part (760) that is connected to a support part and connected to a fixing part (710) at a fixing point (762a), The creepage distance between the fixed point and the support is longer than the creepage distance between the support and the point of application.

[0008] The spring component in the disclosed embodiment is The restoring force that presses the electrical components (521, 550) included in the power conversion circuit (500) against the cooler (600) is provided by a spring body (720) that acts on the electrical components at the point of application (780a), It has a fixing part (710) for fixing the spring body to the cooler, The spring body is A spring portion (780) having a point of application, A support part (770) that supports the spring part, It has a connecting part (760) that is connected to a support part and connected to a fixing part at a fixing point (762a), The creepage distance between the fixed point and the support is longer than the creepage distance between the support and the point of application.

[0009] The power converter in the disclosed embodiment is A power conversion circuit (500) including electrical components (521, 550), A cooler (600) for cooling electrical components, A power conversion device having a spring component (700) that presses an electrical component against a cooler, The spring parts are, The restoring force that presses the electrical component against the cooler is provided by a spring body (720) acting on the electrical component at the point of application (780a), It has a fixing part (710) for fixing the spring body to the cooler, The spring body is A spring portion (780) having a point of application, A support portion (770) that supports a spring portion, and a connecting portion (760) that is connected to the support portion and connected to a fixing portion at a fixing point (762a). The surface distance between the fixing point and the support portion is longer than the surface distance between the support portion and the acting point.

[0010] According to this, the distortion generated at the fixing point (762a) due to fixing is suppressed from affecting the support portion (770). The restoring force acting on the electrical components (521, 550) from the acting point (780a) of the spring portion (780) supported by the support portion (770) is suppressed from fluctuating due to the above distortion.

[0011] The reference numbers in the parentheses above only indicate the correspondence with the configurations described in the embodiments below, and do not limit the technical scope in any way.

Brief Description of Drawings

[0012] [Figure 1] It is a circuit diagram for explaining an in-vehicle system. [Figure 2] It is an exploded cross-sectional view for explaining a spring component. [Figure 3] It is a plan view of a spring body. [Figure 4] It is a side view of a spring body. [Figure 5] It is a side view of a spring body. [Figure 6] It is a plan view of a spring body. [Figure 7] It is a plan view of a spring body. [Figure 8] It is a plan view of a spring body. [Figure 9] It is a side view of a spring body. [Figure 10] It is a plan view of a spring body.

Modes for Carrying Out the Invention

[0013] The following describes several embodiments for implementing this disclosure with reference to the drawings. In later embodiments, parts corresponding to matters described in earlier embodiments may be given the same reference numerals, and redundant explanations may be omitted. If only a part of the configuration is described in each embodiment, the description of the earlier embodiment may be applied to the other parts of the configuration.

[0014] It is possible to combine parts that are explicitly shown to be combinable in each form. Furthermore, if there are no particular problems with the combination, it is also possible to partially combine multiple forms with each other, a form with a modified form, and multiple modified forms with each other, even if it is not explicitly shown that they can be combined.

[0015] In the following, the three directions that are orthogonal to each other will be referred to as the X direction, Y direction, and Z direction. The X, Y, and Z directions are linear directions. In the drawings, the term "direction" is omitted, and they are simply shown as X, Y, and Z. The X direction corresponds to the first direction. The Y direction corresponds to the second direction.

[0016] When this disclosure is mounted on a vehicle, the X direction is aligned with the left-right direction of the vehicle. The Y direction is aligned with the vehicle's forward and backward direction. The Z direction is aligned with the vehicle's up-down direction. When the vehicle is stationary on a horizontal plane, the plane defined by the X and Y directions is aligned with the horizontal direction. The Z direction is aligned with the vertical direction. Hereafter, embodiments will be described assuming that the plane defined by the X and Y directions is aligned with the horizontal direction and the Z direction is aligned with the vertical direction.

[0017] <First Embodiment> <In-vehicle systems> First, based on Figure 1, we will outline the in-vehicle system 100 to which the power converter 300 is applied. This in-vehicle system 100 constitutes a system for an electric vehicle. The in-vehicle system 100 includes a battery 200, a power converter 300, and a motor 400.

[0018] Furthermore, the in-vehicle system 100 has multiple ECUs (not shown). These multiple ECUs transmit and receive signals to each other via bus wiring. The multiple ECUs cooperate to control the electric vehicle. The powering and regeneration of the motor 400 are controlled according to the State of Charge (SOC) of the battery 200 by the control of the multiple ECUs. ECU stands for electronic control unit. SOC stands for state of charge.

[0019] An ECU comprises at least one arithmetic processing unit (CPU) and at least one memory device (MMR) as a recording medium for recording programs and data. The ECU is provided by a microcomputer equipped with a computer-readable recording medium. The recording medium is a non-transitional tangible recording medium that non-temporarily stores computer-readable programs. The recording medium may be provided by semiconductor memory or a magnetic disk, etc.

[0020] Battery 200 has multiple secondary batteries. These secondary batteries form a battery stack connected in series. The state of charge (SOC) of this battery stack corresponds to the state of charge (SOC) of battery 200. As secondary batteries, solid-state batteries, lithium-ion secondary batteries, nickel-metal hydride secondary batteries, and organic radical batteries can be used.

[0021] The power converter 300 performs power conversion between the battery 200 and the motor 400. The power converter 300 converts the DC power from the battery 200 into AC power. The power converter 300 converts the AC power generated by the motor 400's power generation (regeneration) into DC power.

[0022] Motor 400 is connected to the axle of an electric vehicle (not shown). The rotational energy (power) of motor 400 is transmitted to the wheels of the electric vehicle via the axle. Conversely, the rotational energy of the wheels is transmitted to motor 400 via the axle.

[0023] The motor 400 is powered by alternating current (AC) electricity supplied from the power converter 300. This provides propulsion to the wheels. The motor 400 also regenerates energy from the rotational energy transmitted from the wheels. The AC electricity generated by this regeneration is converted into DC electricity by the power converter 300. This DC electricity is supplied to the battery 200 and various electrical loads installed in the electric vehicle.

[0024] <Power converter> Next, the power converter 300 will be described. The power converter 300 has a power conversion circuit 500 and a case 600.

[0025] The components of the power conversion circuit 500 are housed in a case 600. As schematically shown in Figure 2, the case 600 is equipped with a refrigerant passage 610 through which the refrigerant flows. The refrigerant flowing through this refrigerant passage 610 suppresses the temperature rise of the power conversion circuit 500. In Figure 2, the direction of refrigerant flow is indicated by a white arrow.

[0026] <Power Conversion Circuit> The power conversion circuit 500 includes an inverter 510. The inverter 510 converts the DC power from the battery 200 into AC power. This AC power is supplied to the motor 400. The inverter 510 also converts the AC power generated by the motor 400 into DC power. This DC power is supplied to the battery 200. The power conversion circuit 500 may also include a converter that boosts or lowers the input voltage before outputting it.

[0027] The power conversion circuit 500 has an N busbar 501 and a P busbar 502. The battery 200 is connected to these N busbars 501 and P busbars 502. The N busbar 501 is connected to the negative terminal of the battery 200. The P busbar 502 is connected to the positive terminal of the battery 200.

[0028] Furthermore, the power conversion circuit 500 has a U-phase busbar 503, a V-phase busbar 504, and a W-phase busbar 505. The inverter 510 and the motor 400 are electrically connected via these U-phase busbars 503, V-phase busbars 504, and W-phase busbars 505. In Figure 1, the connection points of the various busbars are indicated by white circles. These connection points are electrically connected, for example, by bolts or welding.

[0029] <Inverter> The inverter 510 has a smoothing capacitor 520 and a switch group 530. The N busbar 501 and the P busbar 502 are electrically connected to the smoothing capacitor 520 and the switch group 530.

[0030] The smoothing capacitor 520 is housed in a capacitor case 521. The capacitor case 521 is made of an insulating resin material. Parts of the N busbar 501 and the P busbar 502 are housed in the capacitor case 521. This capacitor case 521 is fixed to the case 600.

[0031] The switch group 530 comprises a U-phase switch module 531, a V-phase switch module 532, and a W-phase switch module 533. These three-phase switch modules have a high-side switch 541 and a low-side switch 542. The three-phase switch modules also have a high-side diode 541a and a low-side diode 542a.

[0032] The switches and diodes of the three-phase switch module are housed in a switch case 550. The switch case 550 is made of an insulating resin material. In this embodiment, the switches and diodes of the three-phase switch module are individually housed in three switch cases 550. Of course, it is also possible to adopt a configuration in which the switches and diodes of the three-phase switch module are housed in a single switch case 550.

[0033] In this embodiment, n-channel IGBTs are used as the high-side switch 541 and the low-side switch 542. As shown in Figure 1, the emitter electrode of the high-side switch 541 and the collector electrode of the low-side switch 542 are connected. This connects the high-side switch 541 and the low-side switch 542 in series.

[0034] Furthermore, the cathode electrode of the high-side diode 541a is connected to the collector electrode of the high-side switch 541. The anode electrode of the high-side diode 541a is connected to the emitter electrode of the high-side switch 541. As a result, the high-side diode 541a is connected in antiparallel to the high-side switch 541.

[0035] Similarly, the cathode electrode of the low-side diode 542a is connected to the collector electrode of the low-side switch 542. The anode electrode of the low-side diode 542a is connected to the emitter electrode of the low-side switch 542. As a result, the low-side diode 542a is connected in antiparallel to the low-side switch 542.

[0036] As described above, the switch is housed in the switch case 550. From this switch case 550, the tip of the collector terminal 540a, which is connected to the collector electrode of the high-side switch 541, and the tip of the output terminal 540b, which is connected to the midpoint between the high-side switch 541 and the low-side switch 542, are exposed. Also, from the switch case 550, the tip of the emitter terminal 540c, which is connected to the emitter electrode of the low-side switch 542, and the tip of the gate terminal 540d, which is connected to the gate electrodes of the high-side switch 541 and the low-side switch 542, are exposed.

[0037] As shown in Figure 1, the collector terminal 540a is connected to the P busbar 502. The emitter terminal 540c is connected to the N busbar 501. Due to these electrical connections, the high-side switch 541 and the low-side switch 542 are connected in series sequentially from the P busbar 502 to the N busbar 501.

[0038] The U-phase busbar 503 is connected to the output terminal 540b of the U-phase switch module 531. The V-phase busbar 504 is connected to the output terminal 540b of the V-phase switch module 532. The W-phase busbar 505 is connected to the output terminal 540b of the W-phase switch module 533.

[0039] Motor 400 has a U-phase stator coil, a V-phase stator coil, and a W-phase stator coil. A U-phase busbar 503 is electrically connected to the U-phase stator coil. A V-phase busbar 504 is electrically connected to the V-phase stator coil. A W-phase busbar 505 is electrically connected to the W-phase stator coil. This electrically connects the inverter 510 and the motor 400.

[0040] The gate terminals 540d of the high-side switch 541 and low-side switch 542 included in the U-phase switch modules 531 to W-phase switch modules 533 are connected to the gate driver.

[0041] The gate driver, along with some of the ECUs mentioned above, is included in the circuit board 560 shown in Figure 1. The ECU generates a control signal and outputs it to the gate driver. The gate driver amplifies the control signal and outputs it to the gate terminal 540d. As a result, the high-side switch 541 and the low-side switch 542 are opened and closed by the ECU. Note that the board on which the gate driver is mounted and the board on which the ECU is mounted may be separate.

[0042] The ECU generates pulse signals as control signals. The ECU adjusts the duty cycle and frequency of these pulse signals. These duty cycle and frequency are determined based on the outputs of various sensors, etc.

[0043] When motor 400 is operating, the high-side switch 541 and low-side switch 542 of the three-phase switch module are PWM controlled by the output of a control signal from the ECU. This generates a three-phase alternating current in the power conversion circuit 500. This three-phase alternating current is input to the three phase stator coils. This generates a three-phase rotating magnetic field in the three phase stator coils. The interaction between this three-phase rotating magnetic field and the magnetic field generated from the rotor of motor 400 generates rotational torque in the rotor.

[0044] When the motor 400 generates electricity (regenerates) due to the rotational energy of the driving wheels, the ECU, for example, stops outputting the control signal. As a result, the AC power generated by the regeneration passes through the diodes of the three-phase switch module. Consequently, the AC power is converted to DC power.

[0045] Furthermore, the type of switch element provided in the U-phase switch modules 531 to W-phase switch modules 533 is not particularly limited; for example, MOSFETs can be used. The semiconductor elements such as switches and diodes included in these three-phase switch modules can be manufactured from semiconductors such as Si and wide-bandgap semiconductors such as SiC. The constituent materials of the semiconductor elements are not particularly limited.

[0046] Furthermore, the number of high-side switches 541 and low-side switches 542 in a three-phase switch module is not limited to one. At least one of the three-phase switch modules may have multiple high-side switches 541 and multiple low-side switches 542 connected in parallel. The number of switches connected in parallel can be determined based on the rated current of the switches and the amount of current that can be energized by the power conversion circuit 500.

[0047] <Case> Case 600 is made of a high-permeability material with higher magnetic permeability than air. Specifically, case 600 is made of a metal material such as aluminum or iron. The capacitor case 521 and the switch case 550 are housed in case 600. The components of the power conversion circuit 500 shown in Figure 1 are housed in case 600. In addition, current sensors and other components not shown are also housed in case 600.

[0048] Case 600 has multiple case members. These are connected via seals, forming a refrigerant passage 610 inside case 600. An input pipe and a discharge pipe are connected to this refrigerant passage 610. These input and discharge pipes are connected to a pump. The refrigerant flowing into the refrigerant passage from the input pipe exchanges heat with the components of the power conversion circuit 500 housed in case 600. This heat-exchanged refrigerant is returned to the pump via the discharge pipe. The temperature of the refrigerant returned to the pump is lowered by a cooling device such as a radiator. This cooled refrigerant is then supplied back to the input pipe. Case 600 acts as a cooler.

[0049] The condenser case 521 is positioned opposite the upstream side of the refrigerant passage 610. The switch case 550 is positioned opposite the downstream side of the refrigerant passage 610. The condenser case 521 and the switch case 550 are pressed and fixed to the case 600. Therefore, the condenser case 521 and the switch case 550 are capable of actively conducting heat to the case 600.

[0050] Due to the configuration described above, the temperature rise of the smoothing capacitor 520 housed in the capacitor case 521 is suppressed mainly by the refrigerant passing upstream of the refrigerant passage 610. The temperature rise of the switch group 530 housed in the switch case 550 is suppressed mainly by the refrigerant passing downstream of the refrigerant passage 610.

[0051] <Spring parts> As described above, the switch case 550 is pressed and fixed to the case 600. In order to realize this configuration, the power converter 300 has a spring component 700 in addition to the power conversion circuit 500 and the case 600.

[0052] The spring component 700 includes a fixing portion 710, a spring body 720, and an equal-pressure sheet 730. The fixing portion 710, the spring body 720, and the equal-pressure sheet 730 have a flattened shape with a thin thickness in the Z direction. The fixing portion 710 is more rigid than the spring body 720. The spring body 720 is more rigid than the equal-pressure sheet 730.

[0053] As shown in Figure 2, the fixing part 710, spring body 720, isobaric sheet 730, switch case 550, and case 600 are stacked in order in the Z direction. The spring body 720, isobaric sheet 730, and switch case 550 are located in the projection area of ​​the fixing part 710 onto case 600 along the Z direction.

[0054] The fixing portion 710 is fixed to the case 600 by the first fixing member 810 in such a manner that it approaches the case 600 in the Z direction. As a result, the spring body 720, the pressure-reducing sheet 730, and the switch case 550 are compressed in the Z direction between the fixing portion 710 and the case 600. The first fixing member 810 is a bolt, rivet, or the like.

[0055] The spring body 720 is fixed to the fixing part 710 by the second fixing member 820 in a manner that approaches the fixing part 710 in the Z direction. This integrates the spring body 720 and the fixing part 710. The spring body 720 is supported by the highly rigid fixing part 710. The second fixing member 820 is a bolt, rivet, or the like.

[0056] As will be described later, the spring body 720 has a spring portion 780 that actively undergoes elastic deformation. Compression in the Z direction by the first fixing member 810 described above generates a restoring force (applied pressure) from the spring portion 780 along the Z direction.

[0057] The isobaric sheet 730 is interposed between the spring portion 780 and the switch case 550. The isobaric sheet 730 is compressed in the Z direction between the spring portion 780 and the switch case 550. The spring portion 780 is indirectly in contact with the switch case 550 via the isobaric sheet 730.

[0058] The restoring force generated in the spring portion 780 acts on the switch case 550 via the pressure equalization sheet 730. The pressure equalization sheet 730 equalizes the restoring force acting from the spring portion 780 to the switch case 550. This suppresses unevenness in the contact state between the switch case 550 and the case 600 depending on the location. It also suppresses significant differences in thermal conductivity between the switch case 550 and the case 600 depending on the location.

[0059] The spring component 700 does not necessarily have to have an equal-pressure sheet 730. In this case, the spring portion 780 directly contacts the switch case 550. The restoring force generated by the spring portion 780 acts directly on the switch case 550.

[0060] <Spring body> The spring body 720 is manufactured by press-forming a thin metal sheet with a thickness in the Z direction. Therefore, the lengths of the various components of the spring body 720 shown below in the X and Y directions are longer than their lengths in the Z direction. For example, if a component has a shape that extends in either the X or Y direction, the longest length in the direction perpendicular to one of the X or Y directions is the length of the other direction.

[0061] The spring body 720 has an upper surface 720a and a lower surface 720b aligned in the Z direction. The upper surface 720a is located closer to the fixed part 710 than the lower surface 720b. The lower surface 720b is located closer to the switch case 550 than the upper surface 720a. The spring body 720 has a symmetrical shape through a first plane of symmetry SP1 that is perpendicular to the X direction and passes through the geometric center of the spring body 720. The spring body 720 also has a symmetrical shape through a second plane of symmetry SP2 that is perpendicular to the Y direction and passes through the geometric center of the spring body 720.

[0062] <Spring Units> The spring body 720 has at least one spring unit 750. In this embodiment, the spring body 720 has three spring units 750. As shown in Figure 3, the three spring units 750 are arranged in the X direction. These three spring units 750 are integrally connected. One spring unit 750 is positioned opposite one switch case 550 in the Z direction. The number of spring units 750 in the spring body 720 is determined according to the size and number of switch cases 550. Note that the spring body 720 is not limited to the switch case 550; it may also press and fix other electrical components, such as a capacitor case 521, to the case 600.

[0063] As shown in Figures 3 to 5, the spring unit 750 has a connecting portion 760, a support portion 770, and a spring portion 780. The connecting portion 760 is fixed to the fixing portion 710. The support portion 770 is connected to the connecting portion 760. The spring portion 780 is supported by the support portion 770. Two spring units 750 that are adjacent to each other in the X direction share a portion of the connecting portion 760.

[0064] <Connection part> The connecting portion 760 has a first connecting portion 761 and a second connecting portion 762. The first connecting portion 761 extends in the X direction. The second connecting portion 762 extends in the Y direction.

[0065] The connecting portion 760 has two first connecting portions 761 and two second connecting portions 762. The two first connecting portions 761 are spaced apart in the Y direction. The two second connecting portions 762 are spaced apart in the X direction. The two first connecting portions 761 are connected via the two second connecting portions 762. As a result, the connecting portion 760 has a frame shape in a plane perpendicular to the Z direction. The support portion 770 and the spring portion 780 are located in the space enclosed by this frame-shaped connecting portion 760.

[0066] The end of the first connecting section 761 and the end of the second connecting section 762 intersect. In the drawing, this intersection area IA is shown enclosed by a dashed line. This intersection area IA extends in both the X and Y directions. The intersection area IA is included in both the first connecting section 761 and the second connecting section 762. The connecting section 760 has four intersection areas IA. The four intersection areas IA correspond to the four corners of the connecting section 760.

[0067] As described above, in this embodiment, three spring units 750 are aligned in the X direction and integrally connected. The spring body 720 having three spring units 750 aligned in the X direction has three sets of two first connecting parts 761 aligned in the Y direction. One pair of the two first connecting parts 761 in these three sets are aligned in the X direction and integrally connected. The other pairs of the two first connecting parts 761 in the three sets are aligned in the X direction and integrally connected.

[0068] Furthermore, a spring body 720 having three spring units 750 aligned in the X direction has four second connecting portions 762 aligned in the X direction. Two adjacent spring units 750 aligned in the X direction share one second connecting portion 762. The spring body 720 has eight of the above-mentioned intersection regions IA.

[0069] In Figure 3, hatching is applied to one of the four second connecting parts 762 aligned in the X direction, specifically the one located at the end and the one adjacent to it in the X direction, located in the center. Similar hatching is applied in Figures 6 and 7, which will be described later.

[0070] The length (width) of the second connecting portion 762 extending in the Y direction is locally elongated in the X direction. In this embodiment, the width of the second connecting portion 762 on the central side in the Y direction is locally elongated. A fixing hole 762a is formed on the central side in the Y direction of this second connecting portion 762. The fixing hole 762a is a through hole that penetrates the upper surface 720a and the lower surface 720b of the second connecting portion 762 in the Z direction. The second fixing member 820 is inserted into this fixing hole 762a. The fixing hole 762a corresponds to the fixing point.

[0071] Of the four second connecting portions 762 aligned in the X direction, the second connecting portions 762 located at the ends are included in one spring unit 750. The second connecting portions 762 located in the center are included in multiple spring units 750. One fixing hole 762a is formed in the two second connecting portions 762 located at the ends. Two fixing holes 762a are formed in the two second connecting portions 762 located in the center.

[0072] <Support part> The support portion 770 extends in the Y direction. The support portion 770 extends from one of the two first connecting portions 761 that are spaced apart in the Y direction to the other. The support portion 770 is located between the two second connecting portions 762 in the X direction. The support portion 770 divides the space enclosed by the frame-shaped connecting portion 760 into two in the X direction.

[0073] The support portion 770 has a first support portion 771 connected to a first connecting portion 761, and a second support portion 772 that supports the spring body 720. In this embodiment, the support portion 770 supports four spring bodies 720. Two spring bodies 720 are supported by one second support portion 772. Therefore, the support portion 770 has two second support portions 772. In addition, the support portion 770 has a third support portion 773 that connects these two second support portions 772.

[0074] The support portion 770 has two first support portions 771 that individually connect two second support portions 772 to two first connecting portions 761. One of the two first support portions 771 connects one of the two second support portions 772 to one of the two second support portions 772. The other of the two first support portions 771 connects the other of the two second support portions 772 to the other of the two second support portions 772.

[0075] Due to the configuration described above, the first support portion 771, the second support portion 772, the third support portion 773, the second support portion 772, and the first support portion 771 are arranged in order and integrally connected between the two first connecting portions 761. Therefore, the second support portion 772 that supports the spring body 720 is connected to the second connecting portion 762, which has a fixing hole 762a formed therein, via the first support portion 771 and the first connecting portion 761.

[0076] A spring body 720 having three spring units 750 aligned in the X direction has three support portions 770 aligned in the X direction. In Figure 3, hatching is applied to one of the three support portions 770 located at the end of the three support portions 770 aligned in the X direction. Similar hatching is applied in Figures 6 and 7, which will be described later.

[0077] <Spring section> The spring portion 780 extends in the Z direction in a manner that separates it from the support portion 770. As shown in Figures 2 and 4, the spring portion 780 is located in the Z direction above the lower surface 720b of the support portion 770, rather than above the upper surface 720a of the support portion 770. The spring portion 780 extends in the Z direction so as to separate it from the support portion 770 in a manner that moves it closer to the switch case 550 side rather than the fixed portion 710 side of the support portion 770.

[0078] The spring portion 780 has a base portion 781 and a tip portion 782. The base portion 781 is cantilevered to the support portion 770. The tip portion 782 is connected to the free end of the base portion 781.

[0079] The base portion 781 extends away from the support portion 770 in the X direction, and its width in the Y direction gradually decreases as it moves away from the support portion 770 in the X direction. The rate at which the width in the Y direction gradually decreases is constant.

[0080] The angle between the lower surface 720b of the base 781 and the reference axis along the Z-direction of the support portion 770 is smaller than the angle between the upper surface 720a of the base 781 and the reference axis. The angle between the lower surface 720b of the base 781 and the reference axis gradually decreases as the base 781 moves away from the support portion 770 in the X-direction.

[0081] The base portion 781 is curved such that as it moves away from the support portion 770 in the X direction, the distance of separation from the support portion 770 in the Z direction gradually increases. The rate at which the distance of separation from the support portion 770 in the Z direction increases gradually as it moves away from the support portion 770 in the X direction. As a result, the base portion 781 is curved so that it is convex from the lower surface 720b toward the upper surface 720a.

[0082] The tip portion 782 extends away from the free end of the base portion 781 in the X direction. The width of the tip portion 782 in the Y direction is constant. The tip portion 782 extends such that the distance from the support portion 770 in the Z direction gradually decreases as it moves away from the free end of the base portion 781 in the X direction. The rate at which the distance from the support portion 770 in the Z direction decreases is constant.

[0083] As a result, the extension direction of the base 781 and the extension direction of the tip 782 in the Z direction are opposite. The angle between the tip 782 and the base 781 on the lower surface 720b is larger than the angle between the tip 782 and the base 781 on the upper surface 720a. The shape of the boundary between the base 781 and the tip 782 on the upper surface 720a is concave from the upper surface 720a to the lower surface 720b. The shape of the boundary between the base 781 and the tip 782 on the lower surface 720b is convex from the upper surface 720a to the lower surface 720b. This convex point on the lower surface 720b will be referred to as the point of application 780a below.

[0084] This point of application 780a is the furthest from the support portion 770 in the Z direction than any other component of the spring portion 780. The point of application 780a contacts the isobaric sheet 730. A restoring force acts from the point of application 780a to the isobaric sheet 730.

[0085] <Length Relationships> As shown in Figure 3, the width in the Y direction of the first connecting portion 761 extending in the X direction is the first length T1. The width in the X direction of the second connecting portion 762 extending in the Y direction is the second length T2. Therefore, the length of the intersection region IA in the Y direction is the first length T1, and the length in the X direction is the second length T2. The first length T1 is shorter than the second length T2. However, the first length T1 may be longer than the second length T2. The first length T1 and the second length T2 may be equal.

[0086] The first connecting portion 761 is connected to the second connecting portion 762 and the support portion 770. The creepage distance between the second connecting portion 762 and the support portion 770 in the first connecting portion 761 is the first creepage distance L1.

[0087] A fixing hole 762a is formed in the second connecting portion 762. The creepage distance between the fixing hole 762a in the second connecting portion 762 and the first connecting portion 761 is the second creepage distance L2. As a result, the creepage distance between the fixing hole 762a and the support portion 770 is the sum of the creepage distances L1 and L2.

[0088] The spring portion 780 is connected to the support portion 770. The creepage distance between the point of application 780a on the lower surface 720b and the support portion 770 is the third creepage distance L3. The third creepage distance L3 is shorter than the first creepage distance L1. Therefore, the third creepage distance L3 is shorter than the sum of the creepage distances L1 + L2. In other words, the sum of the creepage distances L1 + L2 is longer than the third creepage distance L3.

[0089] As described above, the support portion 770 has a first support portion 771, a second support portion 772, and a third support portion 773. In this embodiment, the lengths of the first support portion 771, the second support portion 772, and the third support portion 773 in the X direction are equal. The length of the support portion 770 in the X direction is a third length T3. The third length T3 is approximately the same as the first length T1 and the second length T2. However, the third length T3 may be shorter than at least one of the first length T1 and the second length T2.

[0090] Furthermore, the lengths of the first support portion 771, the second support portion 772, and the third support portion 773 in the X direction do not have to be equal. For example, the length of the first support portion 771 in the X direction may be shorter than at least one of the second support portion 772 and the third support portion 773. In other words, the first support portion 771 may be more prone to deformation than at least one of the second support portion 772 and the third support portion 773.

[0091] The creepage distance refers to the shortest distance between two points on a given plane. Therefore, the first creepage distance L1 represents the shortest distance between the second connecting portion 762 and the support portion 770 on the surface of the connecting portion 760. The second creepage distance L2 represents the shortest distance between the fixing hole 762a and the first connecting portion 761 on the surface of the connecting portion 760. The third creepage distance L3 represents the shortest distance between the point of application 780a and the support portion 770 on the surface of the spring portion 780. The creepage distance between all fixing holes 762a and the support portion 770 is longer than the creepage distance between all points of application 780a and the support portion 770.

[0092] <Effects and Effects> The creepage distance between the fixing hole 762a and the support part 770 is the sum of the creepage distances L1 and L2. The creepage distance between the point of application 780a and the support part 770 is the third creepage distance L3. The sum of the creepage distances L1 and L2 is longer than the third creepage distance L3.

[0093] According to this, the distortion generated in the fixing hole 762a during fixing will not affect the support portion 770. The restoring force acting on the switch case 550 from the point of application 780a of the spring portion 780 supported by the support portion 770 will not fluctuate due to the above-mentioned distortion.

[0094] A first connecting portion 761, which is connected to a support portion 770, and a second connecting portion 762, which has a fixing hole 762a, are connected. The first connecting portion 761 extends in the Y direction, and the second connecting portion 762 extends in the X direction.

[0095] In this manner, the extension directions of the first connecting portion 761 to which the support portion 770 is connected and the extension direction of the second connecting portion 762 having the fixing hole 762a intersect. Therefore, the distortion generated in the fixing hole 762a is suppressed from affecting the support portion 770.

[0096] The longest length of the first connecting portion 761 extending in the X direction in the direction perpendicular to the X direction is the first length T1. The longest length of the second connecting portion 762 extending in the Y direction in the direction perpendicular to the Y direction is the second length T2. This first length T1 is shorter than the second length T2.

[0097] According to this, even if the distortion generated in the fixing hole 762a of the second connecting portion 762 affects the first connecting portion 761, the effect of that distortion on the support portion 770 connected to the first connecting portion 761 is suppressed.

[0098] A fixing hole 762a is formed on the central side of the second connecting portion 762 that extends in the Y direction. This makes it easier to increase the creepage distance between the fixing hole 762a and the support portion 770.

[0099] The length of the support portion 770 in the X direction is the third length T3. The third length T3 may be shorter than the first length T1. The third length T3 may also be shorter than the second length T2.

[0100] If the third length T3 is shorter than at least one of the first length T1 and the second length T2, even if the strain generated in the fixing hole 762a affects the first support portion 771, the effect of that strain on the second support portion 772 is suppressed.

[0101] Furthermore, if the length of the first support portion 771 in the X direction is shorter than at least one of the second support portion 772 and the third support portion 773, the influence of the strain generated in the fixing hole 762a on the second support portion 772 is suppressed.

[0102] <Second Embodiment> This embodiment will be described primarily in terms of its differences from the first embodiment. In subsequent embodiments, the differences from the previously described embodiment will also be described primarily in terms of their differences. Configurations, operations, and effects not specifically described in other embodiments are the same as those described in the previously described embodiment.

[0103] In the first embodiment, an example was shown in which a fixing hole 762a is formed on the central side of the second connecting portion 762 that extends in the Y direction. In contrast, in this embodiment, as shown in Figure 6, the fixing hole 762a is formed in the intersection region IA where the end side of the first connecting portion 761 and the end side of the second connecting portion 762 intersect.

[0104] Fixing holes 762a may be formed in all of the multiple intersection regions IA of the spring body 720. Alternatively, fixing holes 762a may be formed in only a portion of the multiple intersection regions IA of the spring body 720.

[0105] <Third Embodiment> In the first embodiment, an example was shown in which the third support portion 773 is connected to the first connecting portion 761 via the second support portion 772 and the first support portion 771. In contrast, in the present embodiment, as shown in Figure 7, the third support portion 773 is connected to the first connecting portion 761 via the second support portion 772 and the first support portion 771, and is also connected to the second connecting portion 762 via the third connecting portion 763.

[0106] In this embodiment, the connecting portion 760 has the first connecting portion 761 and the second connecting portion 762, as well as the third connecting portion 763 described above. The third connecting portion 763 extends in the X direction. The third connecting portion 763 connects the two second connecting portions 762 via the third support portion 773.

[0107] The fixing hole 762a is formed at the intersection of the extension direction of the third connecting portion 763 in the X direction with the second connecting portion 762. The creepage distance between the fixing hole 762a and the third support portion 773 via the third connecting portion 763 is the first creepage distance L1. This first creepage distance L1 is longer than the third creepage distance L3.

[0108] <Fourth Embodiment> In the first embodiment, an example was shown in which the spring body 720 has three spring units 750. In contrast, in this embodiment, the spring body 720 does not have spring units 750.

[0109] As shown in Figures 8 and 9, the spring body 720 has two first connecting parts 761 and two second connecting parts 762. The spring body 720 has five support parts 770. Four spring parts 780 are connected to three of the five support parts 770. Two spring parts 780 are connected to the remaining two support parts 770.

[0110] In Figure 8, hatching is applied to one of the two second connecting parts 762 aligned in the X direction. Hatching is also applied to one of the three support parts 770 connected to the four spring parts 780, which is located at the end, and to one of the two support parts 770 connected to the two spring parts 780 that are adjacent to it in the X direction. The same applies to Figure 10, which will be described later.

[0111] Support sections 770, each consisting of four connected spring sections 780, and support sections 770, each consisting of two connected spring sections 780, are arranged alternately in the X direction. In the Y direction, two spring sections 780 and three spring sections 780 are arranged in a row.

[0112] The spring body 720 has four intersection regions IA where the end of the first connecting portion 761 and the end of the second connecting portion 762 intersect. Fixing holes 762a are formed in these four intersection regions IA.

[0113] Furthermore, the creepage distance between the two support sections 770 aligned in the X direction is the fourth creepage distance L4. The fourth creepage distance L4 is equal to the first creepage distance L1.

[0114] <Fifth Embodiment> In the fourth embodiment, an example was shown in which fixing holes 762a are formed in four intersecting regions IA. In contrast, in this embodiment, as shown in Figure 10, one fixing hole 762a is formed on the center side in the Y direction of the two second connecting portions 762.

[0115] As a result, the total number of fixing holes 762a is reduced. The total amount of strain generated in the fixing holes 762a is reduced. Therefore, fluctuations in the restoring force acting from the point of application 780a to the switch case 550 due to such strain are suppressed.

[0116] <Other variations> The disclosure in this specification is not limited to the exemplary embodiments. The disclosure encompasses the exemplary embodiments and variations thereof by those skilled in the art. For example, the disclosure is not limited to the combinations of parts and elements shown in the embodiments, but can be implemented in various variations. The disclosure can be implemented in a variety of combinations. The disclosure may have additional parts that can be added to the embodiments. The disclosure encompasses embodiments in which parts and elements have been omitted. The disclosure encompasses substitutions or combinations of parts and elements between one embodiment and another. The scope of the disclosed technical field is not limited to the descriptions of the embodiments. The scope of the disclosed technical field is indicated by the claims and should be understood to include all modifications within the meaning and scope equivalent to the claims.

[0117] In this embodiment, an example is shown in which the power converter 300 is used in the in-vehicle system 100 of an electric vehicle. However, the use of the power converter 300 is not limited to the above example. The power converter 300 can be appropriately used in hybrid vehicles, trucks, drones, robots, and home appliances, etc.

[0118] In this embodiment, the case 600 is shown as housing and cooling the power conversion circuit 500. However, these two functions of housing and cooling may be separated. That is, the case 600 may only house the power conversion circuit 500. A separate component from the case 600 may be configured as a cooler having a refrigerant passage 610 for cooling the power conversion circuit 500.

[0119] <Disclosure of Technical Ideas> This specification discloses several technical concepts, as listed in the following paragraphs. Some paragraphs are written in a multiple dependent form, where subsequent paragraphs optionally refer to preceding paragraphs. Furthermore, some paragraphs are written in a multiple dependent form, referring to other multiple dependent forms. These paragraphs written in multiple dependent forms define several technical concepts. <Technical philosophy 1> A spring body that acts on the electrical components (521, 550) included in the power conversion circuit (500) at the point of application (780a) to press the electrical components (521, 550) against the cooler (600), provides a restoring force. The spring portion (780) having the aforementioned point of application, A support portion (770) that supports the spring portion, It has a connecting part (760) which is connected to the support part and connected to the fixing part (710) at the fixing point (762a), A spring body in which the creepage distance between the fixed point and the support portion is longer than the creepage distance between the support portion and the point of application. <Technical philosophy 2> The connecting portion has a first connecting portion (761) that is connected to the support portion, and a second connecting portion (762) that has the fixing portion. The spring body according to technical concept 1, wherein the first connecting portion extends in a first direction, and the second connecting portion extends in a second direction intersecting the first direction. <Technical philosophy 3> The aforementioned support portion is A first support portion (771) connected to the first connecting portion, It has a second support portion (772) connected to the first support portion and supporting the spring portion, The first support portion and the second support portion extend in the second direction, The spring body according to technical concept 2, wherein the longest length of the first support portion in the direction perpendicular to the second direction is shorter than the longest length of the first connecting portion in the direction perpendicular to the first direction. <Technical philosophy 4> A spring body according to technical idea 2 or technical idea 3, wherein the longest length of the first connecting portion in the direction perpendicular to the first direction is shorter than the longest length of the second connecting portion in the direction perpendicular to the second direction. <Technical philosophy 5> The support portion has two first connecting portions that are separated in the second direction, and two second connecting portions that are separated in the first direction and connected via the two first connecting portions. The two aforementioned second connecting parts are spring bodies according to any one of the technical concepts 2 to 4, wherein each has only one fixing point. <Technical philosophy 6> The spring body according to technical concept 5, wherein one of the fixing points is located on the central side in the second direction of the second connecting portion. <Technical philosophy 7> The restoring force that presses the electrical components (521, 550) included in the power conversion circuit (500) against the cooler (600) is provided by a spring body (720) that acts on the electrical components at the point of application (780a), The spring body has a fixing part (710) for fixing it to the cooler, The aforementioned spring body is The spring portion (780) having the aforementioned point of application, A support portion (770) that supports the spring portion, It has a connecting part (760) which is connected to the support part and connected to the fixing part at the fixing point (762a), A spring component in which the creepage distance between the fixed point and the support portion is longer than the creepage distance between the support portion and the point of application. <Technical philosophy 8> A power conversion circuit (500) including electrical components (521, 550), A cooler (600) for cooling the aforementioned electrical components, A power conversion device having a spring component (700) that presses the electrical component against the cooler, The aforementioned spring component is, The restoring force that presses the electrical component against the cooler is provided by a spring body (720) that acts on the electrical component at the point of application (780a), The spring body has a fixing part (710) for fixing it to the cooler, The aforementioned spring body is The spring portion (780) having the aforementioned point of application, A support portion (770) that supports the spring portion, It has a connecting part (760) which is connected to the support part and connected to the fixing part at the fixing point (762a), A power conversion device in which the creepage distance between the fixed point and the support portion is longer than the creepage distance between the support portion and the point of application. [Explanation of Symbols]

[0120] 100...In-vehicle system, 200...Battery, 300...Power converter, 400...Motor, 500...Power conversion circuit, 521...Capacitor case, 550...Switch case, 600...Case, 600...Cooler, 700...Spring component, 710...Fixing part, 720...Spring body, 730...Isobaric sheet, 750...Spring unit, 760...Connecting part, 761...First connecting part, 762...Second connecting part, 762a...Fixing hole, 770...Support part, 771...First support part, 772...Second support part, 773...Third support part, 780...Spring part, 780a...Point of application, 781...Base, 782...Tip, 810...First fixing member, 820...Second fixing member

Claims

1. A spring body that acts on the electrical components (521, 550) included in the power conversion circuit (500) at the point of application (780a) to press the electrical components (521, 550) against the cooler (600), provides a restoring force. The spring portion (780) having the aforementioned point of application, A support portion (770) that supports the spring portion, It has a connecting part (760) which is connected to the support part and connected to the fixing part (710) at the fixing point (762a), A spring body in which the creepage distance between the fixed point and the support portion is longer than the creepage distance between the support portion and the point of application.

2. The connecting portion has a first connecting portion (761) that is connected to the support portion, and a second connecting portion (762) that has the fixing portion. The spring body according to claim 1, wherein the first connecting portion extends in a first direction, and the second connecting portion extends in a second direction intersecting the first direction.

3. The aforementioned support portion is A first support portion (771) connected to the first connecting portion, It has a second support portion (772) connected to the first support portion and supporting the spring portion, The first support portion and the second support portion extend in the second direction, The spring body according to claim 2, wherein the longest length of the first support portion in the direction perpendicular to the second direction is shorter than the longest length of the first connecting portion in the direction perpendicular to the first direction.

4. The spring body according to claim 2 or 3, wherein the longest length of the first connecting portion in the direction perpendicular to the first direction is shorter than the longest length of the second connecting portion in the direction perpendicular to the second direction.

5. The support portion has two first connecting portions that are separated in the second direction, and two second connecting portions that are separated in the first direction and connected via the two first connecting portions. The spring body according to claim 2 or 3, wherein the two second connecting portions each have only one fixing point.

6. The spring body according to claim 5, wherein one of the fixing points is located on the central side in the second direction of the second connecting portion.

7. The restoring force that presses the electrical components (521, 550) included in the power conversion circuit (500) against the cooler (600) is provided by a spring body (720) that acts on the electrical components at the point of application (780a), The spring body has a fixing part (710) for fixing it to the cooler, The aforementioned spring body is The spring portion (780) having the aforementioned point of application, A support portion (770) that supports the spring portion, It has a connecting part (760) which is connected to the support part and is connected to the fixing part at the fixing point (762a), A spring component in which the creepage distance between the fixed point and the support portion is longer than the creepage distance between the support portion and the point of application.

8. A power conversion circuit (500) including electrical components (521, 550), A cooler (600) for cooling the aforementioned electrical components, A power conversion device having a spring component (700) that presses the electrical component against the cooler, The aforementioned spring component is, The restoring force that presses the electrical component against the cooler is provided by a spring body (720) that acts on the electrical component at the point of application (780a), The spring body has a fixing part (710) for fixing it to the cooler, The aforementioned spring body is The spring portion (780) having the aforementioned point of application, A support portion (770) that supports the spring portion, It has a connecting part (760) which is connected to the support part and is connected to the fixing part at the fixing point (762a), A power conversion device in which the creepage distance between the fixed point and the support portion is longer than the creepage distance between the support portion and the point of application.

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