Cooling device

Abstract

To provide a cooling device capable of extending the product life of a power conversion circuit.SOLUTION: A cooling device 50 includes a plurality of heat exchange units 51, input / output pipes 52 and 53, and a switching device 56. The heat exchange units 51 have flow paths through which cooling water flows, and are stacked so as to cool a plurality of semiconductor elements arranged along the flow paths from both sides. The input / output pipes 52 and 53 input and output cooling water to and from the flow path of each heat exchange unit 51. The switching device 56 is configured to be capable of performing a switching operation between a first mode in which cooling water is input to the flow paths through the input / output pipe 52 and the cooling water that has flowed through the flow paths is output through the input / output pipe 53, and a second mode in which cooling water that has flowed through the flow paths is output through the input / output pipe 52 and the cooling water is input to the flow paths through the input / output pipe 53.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The disclosure in this specification relates to a cooling device for cooling semiconductor elements constituting a power conversion circuit.

Background Art

[0002] Patent Document 1 discloses a cooling device for cooling an inverter. The description of the prior art document is incorporated herein by reference as an explanation of the technical elements in this specification.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As a cooling device, a configuration in which a plurality of heat exchange parts are stacked is known. Each of the plurality of heat exchange parts has a flow path through which cooling water flows. The plurality of heat exchange parts cool a plurality of semiconductor elements arranged along the flow path from both sides by the stacked arrangement. In this configuration, the semiconductor elements closer to the outlet of the cooling water in the heat exchange part have a lower reduction effect of the heat load by the cooling water than the semiconductor elements closer to the inlet. Therefore, the lifespan of the semiconductor elements near the outlet is shorter than the lifespan of the semiconductor elements near the inlet. Thus, the product lifespan of the power conversion circuit composed of a plurality of semiconductor elements is determined by the lifespan of specific semiconductor elements. From the above viewpoints, or from other viewpoints not mentioned, further improvement of the cooling device is required.

[0005] One object of the present disclosure is to provide a cooling device capable of extending the product lifespan of a power conversion circuit.

Means for Solving the Problems

[0006] One aspect of the disclosure is a cooling device, having a flow path (511) through which cooling water flows, and a plurality of heat exchange parts (51) stacked so as to cool a plurality of semiconductor elements (41) arranged along the flow path from both sides, a first input / output pipe (52) and a second input / output pipe (53) for inputting and outputting cooling water to and from the flow path of each heat exchange part, a switching device (56) configured to be able to switch between a first mode in which cooling water is input to the flow path via the first input / output pipe and the cooling water that has flowed through the flow path is output via the second input / output pipe, and a second mode in which the cooling water that has flowed through the flow path is output via the first input / output pipe and cooling water is input to the flow path via the second input / output pipe, and comprising.

[0007] According to the disclosed cooling device, a switching device is provided. The switching device is configured to be able to switch between the above-described first mode and second mode. By switching between the first mode and the second mode, it is possible to suppress the bias of the heat load of the semiconductor element. Therefore, the product life of the power conversion circuit composed of a plurality of semiconductor elements can be extended.

[0008] The plurality of aspects disclosed in this specification employ different technical means in order to achieve their respective purposes. The scope of the claims and the reference numerals in parentheses described in this column exemplarily show the correspondence with the parts of the embodiments described later, and are not intended to limit the technical scope. The objects, features, and effects disclosed in this specification will become clearer by referring to the subsequent detailed description and the accompanying drawings.

Brief Description of the Drawings

[0009]

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Embodiments for Carrying Out the Invention

[0010] Hereinafter, a plurality of embodiments will be described with reference to the drawings. In each embodiment, the same reference numerals may be assigned to corresponding components, and redundant descriptions may be omitted. When only a part of the configuration is described in each embodiment, the configuration of other embodiments described previously can be applied to other parts of the configuration. In addition, not only the combinations of configurations explicitly shown in the description of each embodiment, but also the configurations of a plurality of embodiments can be partially combined with each other without any problem in the combination, even if not explicitly shown.

[0011] The cooling device of this embodiment cools a semiconductor element (semiconductor device). The semiconductor device is used, for example, in a power conversion device of a moving body having a rotating electric machine as a drive source. The moving body is, for example, an electric vehicle (BEV), a hybrid vehicle (HV), a plug-in hybrid vehicle (PHV), or other electric vehicles, a flying body such as a drone, a ship, a construction machine, or an agricultural machine. Hereinafter, an example applied to a vehicle will be described.

[0012] (First Embodiment) First, based on FIG. 1, the schematic configuration of the drive system of the vehicle will be described. FIG. 1 is a diagram showing a power conversion circuit and a drive system.

[0013] <Drive System of Vehicle> As shown in FIG. 1, the drive system 1 of the vehicle includes a DC power supply 2, a motor generator 3, and a power conversion circuit 4.

[0014] The DC power supply 2 is a DC voltage source composed of a rechargeable secondary battery. The secondary battery is, for example, a lithium-ion battery, a nickel-metal hydride battery, or the like. The motor generator 3 is a three-phase AC rotating electrical machine. The motor generator 3 functions as a driving source for vehicle running, that is, as an electric motor. The motor generator 3 functions as a generator during regeneration. The power conversion circuit 4 performs power conversion between the DC power supply 2 and the motor generator 3.

[0015] <Power conversion circuit> Next, based on FIG. 1, the power conversion circuit will be described. The power conversion circuit 4 illustrated in FIG. 1 includes a smoothing capacitor 5 and an inverter 6.

[0016] The smoothing capacitor 5 mainly smooths the DC voltage supplied from the DC power supply 2. The smoothing capacitor 5 is connected to the P line 7 which is the power supply line on the high potential side and the N line 8 which is the power supply line on the low potential side. The P line 7 is connected to the positive electrode of the DC power supply 2, and the N line 8 is connected to the negative electrode of the DC power supply 2. The positive electrode of the smoothing capacitor 5 is connected to the P line 7 between the DC power supply 2 and the inverter 6. The negative electrode of the smoothing capacitor 5 is connected to the N line 8 between the DC power supply 2 and the inverter 6. The smoothing capacitor 5 is connected in parallel with the DC power supply 2.

[0017] The inverter 6 is a DC-AC conversion circuit. The inverter 6 converts the DC voltage into a three-phase AC voltage according to the switching control by a control circuit (not shown) and outputs it to the motor generator 3. Thereby, the motor generator 3 is driven to generate a predetermined torque. During the regenerative braking of the vehicle, the inverter 6 converts the three-phase AC voltage generated by the motor generator 3 receiving the rotational force from the wheels into a DC voltage according to the switching control by the control circuit and outputs it to the P line 7. In this way, the inverter 6 performs bidirectional power conversion between the DC power supply 2 and the motor generator 3.

[0018] The inverter 6 is configured to include upper and lower arm circuits 9 for three phases. The upper and lower arm circuits 9 may be referred to as legs. The upper and lower arm circuits 9 each have an upper arm 9H and a lower arm 9L. The upper arm 9H and the lower arm 9L are serially connected between the P line 7 and the N line 8 with the upper arm 9H on the P line 7 side. The connection point between the upper arm 9H and the lower arm 9L is connected to the corresponding phase winding 3a in the motor generator 3 via the output line 10. The inverter 6 has six arms. Each arm is configured to include a switching element. At least a part of each of the P line 7, the N line 8, and the output line 10 is constituted by a conductive member such as a bus bar.

[0019] In this embodiment, an n-channel type MOSFET 11 is adopted as the switching element constituting each arm. The number of switching elements constituting each arm is not particularly limited. It may be one or a plurality. MOSFET is an abbreviation for Metal Oxide Semiconductor Field Effect Transistor.

[0020] As an example, in this embodiment, each arm has one MOSFET 11. In the upper arm 9H, the drain of the MOSFET 11 is connected to the P line 7. In the lower arm 9L, the source of the MOSFET 11 is connected to the N line 8. The source of the MOSFET 11 in the upper arm 9H and the drain of the MOSFET 11 in the lower arm 9L are connected to each other.

[0021] A freewheeling diode 12 is connected in anti-parallel to each of the MOSFETs 11. The diode 12 may be a parasitic diode (body diode) of the MOSFET 11 or may be provided separately from the parasitic diode. The anode of the diode 12 is connected to the source of the corresponding MOSFET 11, and the cathode is connected to the drain.

[0022] Note that the switching element is not limited to the MOSFET 11. For example, an IGBT may be adopted. IGBT is an abbreviation for Insulated Gate Bipolar Transistor. Also in the case of an IGBT, a freewheeling diode is connected in anti-parallel.

[0023] The power conversion circuit 4 may further include a converter. The converter is a DC-DC conversion circuit that converts a DC voltage into, for example, a DC voltage of a different value. The converter is provided between the DC power supply 2 and the smoothing capacitor 5. The converter is configured to include, for example, a reactor and the upper and lower arm circuits 9 described above. According to this configuration, step-up and step-down are possible. The power conversion circuit 4 may include a filter capacitor for removing power supply noise from the DC power supply 2. The filter capacitor is provided between the DC power supply 2 and the converter.

[0024] <Power Conversion Device> Next, based on FIGS. 2, 3, and 4, the schematic configuration of the power conversion device will be described. FIG. 2 is a plan view showing an example of a power conversion device provided with a cooling device. In FIG. 2, for the sake of convenience, wiring elements (such as bus bars) and external connection terminals that electrically connect the respective elements are omitted. FIG. 3 is a plan view showing an example of a semiconductor device. FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. 2. In FIG. 4, the capacitor is omitted. In FIG. 4, for the sake of convenience, the semiconductor device is shown in a simplified manner.

[0025] The power conversion device 20 shown in FIG. 2 provides the above-described power conversion circuit 4. The power conversion device 20 includes a capacitor 30, a semiconductor device 40 including a plurality of semiconductor elements 41, and a cooling device 50. The power conversion device 20 may further include a housing (not shown). The housing houses other elements of the power conversion device 20, such as the capacitor 30, the semiconductor device 40, and the cooling device 50. The power conversion device 20 may further include a drive circuit for a switching element that constitutes an inverter 6 or the like. The drive circuit supplies a drive voltage to the gate of the MOSFET 11 of the corresponding arm based on a drive command from the control circuit. The drive circuit may be referred to as a driver. The drive circuit is provided, for example, as a circuit board.

[0026] The power conversion device 20 may include a control circuit for the switching element. The control circuit generates a drive command for operating the MOSFET 11 and outputs it to the drive circuit. The control circuit generates a drive command based on, for example, a torque request input from a higher-level ECU (not shown) and signals detected by various sensors. ECU is an abbreviation for Electronic Control Unit. Examples of the various sensors include a current sensor, a rotation angle sensor, and a voltage sensor. The current sensor detects the phase current flowing through the winding 3a of each phase. The rotation angle sensor detects the rotation angle of the rotor of the motor generator 3. The voltage sensor detects the voltage across the smoothing capacitor 5. The control circuit outputs, for example, a PWM signal as a drive command. The control circuit is configured to include, for example, a processor and a memory. PWM is an abbreviation for Pulse Width Modulation.

[0027] Hereinafter, the stacking direction of the plurality of heat exchange portions is defined as the X direction. One direction orthogonal to the X direction is defined as the Y direction. The direction orthogonal to both the X direction and the Y direction is defined as the Z direction. The X direction, the Y direction, and the Z direction are in a mutually orthogonal positional relationship. A plan view from the Z direction may be simply referred to as a plan view.

[0028] The capacitor 30 provides the capacitor element of the power conversion circuit 4. The capacitor 30 illustrated in FIG. 2 provides the smoothing capacitor 5. The capacitor 30 includes a capacitor element (not shown). The capacitor element is, for example, a film capacitor element. The capacitor element may be accommodated in a capacitor case, for example. The capacitor element may be sealed with a sealing body such as an epoxy resin while being accommodated in the capacitor case. The number of capacitor elements accommodated in the capacitor case is not particularly limited. It may be only one or a plurality.

[0029] The capacitor 30 includes a plurality of terminals (not shown) electrically connected to the capacitor element. The terminals include a positive terminal electrically connected to the positive electrode side of the capacitor element and a negative terminal electrically connected to the negative electrode side of the capacitor element. The capacitor 30 may be referred to as a capacitor module, a capacitor device, or the like.

[0030] The semiconductor device 40 provides the above-described upper and lower arm circuits 9, that is, the inverter 6. The power conversion device 20 of the present embodiment includes six semiconductor devices 40. One semiconductor device 40 provides one arm. That is, one semiconductor device 40 provides the upper arm 9H or the lower arm 9L. The power conversion device 20 includes three semiconductor devices 40 that provide the upper arm 9H and three semiconductor devices 40 that provide the lower arm 9L. The semiconductor device 40 may be referred to as a semiconductor module, a power module, a power card, or the like. In the example shown in FIG. 2, the semiconductor device 40 is arranged above the capacitor 30 in the Z direction. The arrangement of the capacitor 30 and the semiconductor device 40 is not limited to this example, and may be, for example, a side-by-side arrangement in the X direction or the Y direction.

[0031] All semiconductor devices 40 have a common structure with each other. As shown in FIGS. 3 and 4, the semiconductor device 40 includes a semiconductor element 41. The semiconductor element 41 is formed by forming a switching element on a semiconductor substrate made of silicon (Si), a wide-bandgap semiconductor having a wider bandgap than silicon, or the like. The switching element has a vertical structure so that a main current flows in the thickness direction of the semiconductor substrate. Examples of the wide-bandgap semiconductor include silicon carbide (SiC), gallium nitride (GaN), gallium oxide (Ga2O3), and diamond. The semiconductor element 41 may be referred to as a power element, a semiconductor chip, or the like.

[0032] The semiconductor element 41 of the present embodiment is formed by forming the above-described n-channel type MOSFET 11 and diode 12 on a semiconductor substrate made of SiC. The MOSFET 11 has a vertical structure so that a main current flows in the thickness direction of the semiconductor element 41 (semiconductor substrate). The semiconductor element 41 has main electrodes on both surfaces in its thickness direction. Specifically, as the main electrodes of the switching element, it has a source electrode on the surface and a drain electrode on the back surface. The source electrode is formed on a part of the surface. The drain electrode is formed on substantially the entire back surface.

[0033] The main current flows between the drain electrode and the source electrode. The semiconductor element 41 has a pad (not shown) which is a signal electrode on the formation surface of the source electrode. The semiconductor element 41 is arranged such that its thickness direction is substantially parallel to the X direction. Each semiconductor device 40 includes one semiconductor element 41 having the above-described configuration.

[0034] The semiconductor device 40 may further include a sealing body, a wiring member, terminals, etc. The semiconductor device 40 illustrated in FIG. 3 includes a sealing body 42, a wiring member 43, a main terminal 44, and a signal terminal 45. The sealing body 42 seals a part of other elements constituting the semiconductor device 40. The remaining part of the other elements is exposed outside the sealing body 42. The sealing body 42 is made of, for example, resin. The sealing body 42 is formed by, for example, a transfer molding method using an epoxy resin as a material. The sealing body 42 may be formed using, for example, a gel.

[0035] The sealing body 42 has, for example, a substantially rectangular planar shape. The sealing body 42 has a front surface 421 as a surface forming the outer contour and a back surface (not shown) which is opposite to the front surface 421 in the X direction. The front surface 421 and the back surface are, for example, flat surfaces. The sealing body 42 has side surfaces which are surfaces connecting the front surface 421 and the back surface. The side surfaces include a side surface 422 from which the main terminal 44 protrudes and a side surface 423 from which the signal terminal 45 protrudes. The side surface 422 is opposite to the side surface 423 in the Z direction.

[0036] The wiring member 43 provides a wiring function for electrically connecting the main electrode of the semiconductor element 41 and the main terminal 44. The wiring member 43 may provide a heat dissipation function for dissipating the heat of the semiconductor element 41. The wiring member 43 is arranged, for example, so as to sandwich the semiconductor element 41 in the X direction. The wiring member 43 includes a wiring member electrically connected to the source electrode of the semiconductor element 41 and a wiring member electrically connected to the drain electrode. As the wiring member 43, a substrate having metal bodies arranged on both sides of an insulating base material may be used, or a heat sink which is a metal member may be adopted. The heat sink is provided, for example, as a part of a lead frame. As illustrated in FIG. 3, a part of the wiring member 43 may be exposed from at least one of the front surface 421 and the back surface of the sealing body 42. Thereby, the heat dissipation performance can be enhanced.

[0037] The main terminal 44 is an external connection terminal electrically connected to the main electrode of the semiconductor element 41. As an example, the semiconductor device 40 of the present embodiment includes a main terminal 44 electrically connected to the source electrode and a main terminal 44 electrically connected to the drain electrode. The two main terminals 44 protrude externally from the common side surface 422.

[0038] The signal terminal 45 is an external connection terminal electrically connected to the pad of the semiconductor element 41. The signal terminal 45 protrudes from the side surface 423 of the sealing body 42. The signal terminal 45 extends in a direction opposite to that of the main terminal 44 in the Z direction.

[0039] The cooling device 50 cools the semiconductor device 40 (semiconductor element 41). The cooling device 50 may be referred to as a cooler or the like. The cooling device 50 is formed using a metal material having excellent thermal conductivity, for example, an aluminum-based material. The cooling device 50 includes a plurality of heat exchange portions 51, input / output pipes 52, 53, an inlet 54, an outlet 55, and a switching device 56. The heat exchange portion 51 is a tubular body having an overall flat shape. The heat exchange portion 51 has a flow path 511 through which cooling water 57 flows inside as shown in FIG. 4. The cooling water 57 is, for example, LLC. LLC is an abbreviation for Long Life Coolant. The flow path 511 extends in the Y direction.

[0040] The heat exchange portion 51 is formed by processing at least one of a pair of plates (thin metal plates) into a shape bulged in the X direction by pressing. Thereafter, the outer peripheral edge portions of the pair of plates are fixed to each other by caulking or the like and joined to each other over the entire circumference by brazing or the like. Thereby, a flow path 511 through which the cooling water 57 can flow is formed between the pair of plates, and it becomes possible to use it as the heat exchange portion 51.

[0041] The plurality of heat exchange units 51 are stacked and arranged in the X direction. The heat exchange units 51 are arranged in multiple stages. The heat exchange units 51 are alternately arranged with the semiconductor device 40 so as to cool the semiconductor element 41 (semiconductor device 40) from both sides in the X direction. The semiconductor device 40 is sandwiched by the heat exchange units 51 in the X direction. As illustrated in FIG. 4, a plurality of semiconductor elements 41 (a plurality of semiconductor devices 40) are arranged along the flow path 511. Two semiconductor elements 41 (semiconductor devices 40) are arranged side by side in the extending direction of the flow path 511.

[0042] Note that an electrical insulating member may be interposed between the heat exchange unit 51 and the semiconductor device 40 as necessary. As the insulating member, for example, a ceramic plate, a heat conductive member such as TIM, and combinations thereof can be adopted. TIM is an abbreviation for Thermal Interface Material.

[0043] The input / output pipes 52, 53 input and output the cooling water 57 to and from the flow path 511 of each heat exchange unit 51. The input / output pipes 52, 53 are tubular members that connect the heat exchange unit 51 to the inlet 54 and the outlet 55. The input / output pipes 52, 53 are connected to each of the heat exchange units 51. The input / output pipes 52, 53 are continuous near both ends in the extending direction of the flow path 511. The input / output pipes 52, 53 function as an input pipe for inputting (introducing) the cooling water 57 to the heat exchange unit 51 (flow path 511), or as a discharge pipe for discharging the cooling water 57 that has flowed through the heat exchange unit 51 (flow path 511). By means of the switching device 56, one of the input / output pipes 52, 53 functions as an input pipe, and the other functions as an output pipe. Also, the functions as the input pipe and the output pipe are switched at a predetermined timing. Details of the switching device 56 will be described later.

[0044] <Switching device> Next, the switching device will be described with reference to FIG. 2, FIG. 4, and FIG. 5 to FIG. 9. FIG. 5 is a view of the cooling device as seen from the X1 direction shown in FIG. 2. FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG. 2. FIG. 7 is a cross-sectional view taken along the line VII-VII in FIG. 2. For convenience, FIG. 6 and FIG. 7 show only the flow path in the switching device. FIG. 8 is a cross-sectional view taken along the line VIII-VIII in FIG. 5, showing the input solenoid valve. FIG. 9 is a cross-sectional view taken along the line IX-IX in FIG. 5, showing the output solenoid valve. Both FIG. 8 and FIG. 9 show the state of mode 1. In FIG. 8 and FIG. 9, in order to explain the driving direction of the movable part, the direction toward the detection part side in the Y direction is shown as the +Y direction, and the direction toward the opposite side of the detection part is shown as the -Y direction. In FIG. 8 and FIG. 9, the flow of the cooling water is shown by arrows.

[0045] The switching device 56 is provided between the input / output pipes 52, 53 and the inlet 54 and outlet 55 in the flow path of the cooling water. The switching device 56 determines which of the input / output pipes 52, 53 are to be connected. The switching device 56 connects one of the input / output pipes 52, 53 to the inlet 54 and connects the other to the outlet 55. The switching device 56 switches (alternates) which of the input / output pipes 52, 53 are to be connected at a predetermined timing. The switching device 56 is configured to be able to set a first mode (MODE1) in which the input / output pipe 52 is connected to the inlet 54 and the input / output pipe 53 is connected to the outlet 55, and a second mode (MODE2) in which the input / output pipe 52 is connected to the outlet 55 and the input / output pipe 53 is connected to the inlet 54. The input / output pipe 52 corresponds to the first input / output pipe, and the input / output pipe 53 corresponds to the second input / output pipe.

[0046] The switching device 56 includes an input solenoid valve 60 for selecting one of the input / output pipes 52, 53 as an input pipe and for causing it to function, and an output solenoid valve 70 for selecting the other of the input / output pipes 52, 53 as an output pipe and for causing it to function. As shown in Fig. 8, the input solenoid valve 60 includes a valve body 61, a flow path 62, a solenoid 63, a movable part 64, a detection part 65, and a fixed part 66.

[0047] The flow path 62 is provided in the valve body 61. The flow path 62 is an internal flow path of the valve. The flow path 62 has a configuration of one input and two outputs. The flow path 62 has one input path 621 and two output paths 622 and 623. The input path 621 is connected to the above-described inlet 54. When a pump (not shown) is operated, cooling water is supplied from the input path 621 through the inlet 54. The output path 622 is connected to the input / output pipe 52. The output path 623 is connected to the input / output pipe 53.

[0048] The solenoid 63 may be referred to as a coil, an electromagnet, etc. The solenoid 63 drives the movable part 64 by energization. The solenoid 63 may drive the movable part 64 by an attractive force or may drive the movable part 64 by a repulsive force. The solenoid 63 generates an attractive force or a repulsive force with respect to the movable part 64 according to the applied voltage direction. The solenoid 63 includes two solenoids 631 and 632. The solenoids 631 and 632 are arranged side by side in the Y direction with a predetermined interval.

[0049] The movable part 64 may be referred to as a plunger, etc. The movable part 64 has two movable parts 641 and 642 and a connecting part 643. The movable parts 641 and 642 are arranged side by side in the Y direction with a predetermined interval. The connecting part 643 connects the two movable parts 641 and 642. The movable part 641 is arranged on the solenoid 631 side in the Y direction and receives the action of the solenoid 631. The movable part 642 is arranged on the solenoid 632 side and receives the action of the solenoid 632.

[0050] The movable part 64 extends in the Y direction. The movable part 641 has a valve body 641V and an end part 641E. The valve body 641V is provided at the tip of the movable part 641 on the flow path 62 side in the Y direction, and the end part 641E is provided at the rear end of the movable part 641. Similarly, the movable part 642 has a valve body 642V and an end part 642E. The valve body 641V is provided so as to block the output path 622 when the movable part 64 is driven in the -Y direction. The valve body 642V is provided so as to block the output path 623 when the movable part 64 is driven in the +Y direction.

[0051] The detection unit 65 is a contact or non-contact position sensor. When the end portion 641E retracts to a predetermined position due to the movable portion 64 being driven in the +Y direction, the detection unit 65 detects the end portion 641E. The detection unit 65 detects whether the end portion 641E exists at a predetermined position. The detection unit 65 may be provided only on one end side of the valve body 61 in the Y direction, or may be provided on both end sides respectively. As an example, in this embodiment, it is provided only on one end side.

[0052] The fixing unit 66 locks the non-energized side of the movable portions 641 and 642 in order to restrict the movement of the movable portion 64 due to vehicle vibration or the pressure of the cooling water. The locking mechanism by the fixing unit 66 is not particularly limited. For example, a mechanical type using a spring or the like may be used. As an example, the fixing unit 66 of this embodiment fixes the end portions 641E and 642E. The fixing unit 66 includes two fixing portions 661 and 662. The fixing portion 661 fixes the end portion 641E, and the fixing portion 662 fixes the end portion 642E.

[0053] The output solenoid valve 70 has the same configuration as the input solenoid valve 60. The output solenoid valve 70 is arranged side by side with the input solenoid valve 60 in the switching device 56. As an example, the output solenoid valve 70 of this embodiment is arranged side by side with the input solenoid valve 60 in the Z direction. As shown in FIG. 9, the output solenoid valve 70 includes a valve body 71, a flow path 72, a solenoid 73, a movable portion 74, a detection unit 75, and a fixing unit 76.

[0054] The flow path 72 is provided in the valve body 71. The flow path 72 is an internal flow path of the valve. The flow path 72 has a configuration of two inputs and one output. The flow path 72 has two input paths 721, 722 and one output path 723. The input path 721 is connected to the input / output pipe 52. The input path 721 and the output path 622 are connected to the common input / output pipe 52 by a joint. The input path 722 is connected to the input / output pipe 53. The input path 722 and the output path 623 are connected to the common input / output pipe 53 by a joint. The output path 723 is connected to the above-described outlet 55.

[0055] The solenoid 73 drives the movable part 74 when energized. The solenoid 73 may drive the movable part 74 by an attractive force or may drive the movable part 74 by a repulsive force. The solenoid 73 generates an attractive force or a repulsive force with respect to the movable part 74 according to the applied voltage direction. The solenoid 73 includes two solenoids 731, 732 arranged in the Y direction with a predetermined interval.

[0056] The movable part 74 has two movable parts 741, 742 and a connecting part 743. The movable parts 741, 742 are arranged in the Y direction with a predetermined interval. The connecting part 743 connects the two movable parts 741, 742. The movable part 741 is arranged on the solenoid 731 side in the Y direction and is hand-woven and receives the action of the solenoid 731. The movable part 742 is arranged on the solenoid 732 side and receives the action of the solenoid 732.

[0057] The movable part 74 extends in the Y direction. The movable part 741 has a valve body 741V and an end part 741E. The valve body 741V is provided at the tip of the movable part 741 on the flow path 72 side in the Y direction, and the end part 741E is provided at the rear end of the movable part 741. Similarly, the movable part 742 has a valve body 742V and an end part 742E. The valve body 741V is provided so as to block the input path 721 when the movable part 74 is driven in the -Y direction. The valve body 742V is provided so as to block the input path 722 when the movable part 74 is driven in the +Y direction.

[0058] The detection unit 75 is a contact or non-contact position sensor. When the movable part 74 is driven in the +Y direction and the end part 741E retracts to a predetermined position, the detection unit 75 detects the end part 741E. The detection unit 75 detects whether the end part 741E exists at the predetermined position.

[0059] The fixing part 76 locks the non-energized side of the movable parts 741 and 742 in order to restrict the movement of the movable part 74 due to vehicle vibration or the pressure of the cooling water. As an example, the fixing part 76 of the present embodiment includes two fixing parts 761 and 762. The fixing part 761 fixes the end part 741E, and the fixing part 762 fixes the end part 742E.

[0060] <Mode 1, 2> Next, based on FIGS. 8 to 11, Mode 1 and 2 will be described. FIG. 10 shows the input solenoid valve in the state of Mode 2. FIG. 11 shows the output solenoid valve in the state of Mode 2. FIG. 10 corresponds to FIG. 8, and FIG. 11 corresponds to FIG. 9. Similar to FIGS. 8 and 9, the +Y direction and the -Y direction are shown. Also, the flow of the cooling water is indicated by an arrow.

[0061] The switching device 56 applies a voltage (a positive voltage) to the solenoids 632 and 731 at a predetermined timing to switch to the state of Mode 1. By applying a voltage to the solenoid 632, the movable part 642 of the input solenoid valve 60 is driven in the +Y direction, for example, by a repulsive force. When the end part 642E is driven in the +Y direction, the fixing part 662 is pushed down, and the end part 642E passes through the fixing part 662. The valve body 642V of the movable part 642 moves forward with respect to the flow path 62 and closes the output path 623. Along with the movement of the movable part 642, the movable part 641 is also driven in the +Y direction. The valve body 641V of the movable part 641 moves backward with respect to the flow path 62 and opens the output path 622. When the end part 641E is driven in the +Y direction, the fixing part 661 is pushed down, and the end part 641E passes through the fixing part 661 and is locked by the fixing part 661. In the locked state, the end part 641E is detected by the detection unit 65.

[0062] By applying a voltage to the solenoid 731, the movable part 741 of the output solenoid valve 70 is driven in the -Y direction, for example, by a repulsive force. Due to the driving of the end part 741E in the -Y direction, the fixed part 761 is pushed down, and the end part 741E passes through the fixed part 761. The valve body 741V of the movable part 741 advances with respect to the flow path 72 and closes the input path 721. Along with the movement of the movable part 741, the movable part 742 is also driven in the -Y direction. The valve body 742V of the movable part 742 retreats with respect to the flow path 72 and opens the input path 722. Due to the driving of the end part 742E in the -Y direction, the fixed part 762 is pushed down, and the end part 742E passes through the fixed part 762 and is locked by the fixed part 762.

[0063] The switching device 56 may stop applying a voltage to the solenoids 632 and 731, for example, when a predetermined time has elapsed since the start of voltage application. When the end part 641E is detected by the detection unit 65, the voltage application to the solenoids 632 and 731 may be stopped. Since the end parts 641E and 742E are locked by the corresponding fixed parts 661 and 762, the positions of the movable parts 64 and 74 are held (maintained) even when the energization is cut off.

[0064] In mode 1, as shown in FIG. 8, the valve body 642V of the input solenoid valve 60 closes the output path 623, and as shown in FIG. 9, the valve body 741V of the output solenoid valve 70 closes the input path 721. Therefore, the cooling water on the supply side flows from the inlet 54 to the input / output pipe 52 through the input path 621 and the output path 622. The cooling water on the discharge side flows from the input / output pipe 53 to the outlet 55 through the input path 722 and the output path 723. That is, the input / output pipe 52 functions as an input pipe, and the input / output pipe 53 functions as an output pipe.

[0065] The switching device 56 applies a voltage (a positive voltage) to the solenoids 631 and 732 at a predetermined timing to switch to the state of Mode 2. By applying a voltage to the solenoid 631, the movable part 641 of the input solenoid valve 60 is driven in the -Y direction by, for example, a repulsive force. Due to the driving of the end part 641E in the -Y direction, the fixed part 661 is pushed down, and the end part 641E passes through the fixed part 661. The valve body 641V of the movable part 641 advances with respect to the flow path 62 and closes the output path 622. Along with the movement of the movable part 641, the movable part 642 is also driven in the -Y direction. The valve body 642V of the movable part 642 retreats with respect to the flow path 62 and opens the output path 623. Due to the driving of the end part 642E in the -Y direction, the fixed part 662 is pushed down, and the end part 642E passes through the fixed part 662 and is locked by the fixed part 662.

[0066] By applying a voltage to the solenoid 732, the movable part 742 of the output solenoid valve 70 is driven in the +Y direction by, for example, a repulsive force. Due to the driving of the end part 742E in the +Y direction, the fixed part 762 is pushed down, and the end part 742E passes through the fixed part 762. The valve body 742V of the movable part 742 advances with respect to the flow path 72 and closes the input path 722. Along with the movement of the movable part 742, the movable part 741 is also driven in the +Y direction. The valve body 741V of the movable part 741 retreats with respect to the flow path 72 and opens the input path 721. Due to the driving of the end part 741E in the +Y direction, the fixed part 761 is pushed down, and the end part 741E passes through the fixed part 761 and is locked by the fixed part 761. In the locked state, the end part 741E is detected by the detection part 75.

[0067] The switching device 56 may stop applying a voltage to the solenoids 631 and 732, for example, when a predetermined time has elapsed since the start of voltage application. When the end part 741E is detected by the detection part 75, the switching device 56 may stop applying a voltage to the solenoids 631 and 732. Since the end parts 642E and 741E are locked by the corresponding fixed parts 662 and 761, the positions of the movable parts 64 and 74 are held (maintained) even if the energization is cut off.

[0068] In Mode 2, as shown in FIG. 10, the valve body 641V of the input solenoid valve 60 closes the output passage 622, and as shown in FIG. 11, the valve body 742V of the output solenoid valve 70 closes the input passage 722. Therefore, the cooling water on the supply side flows from the inlet 54 through the input passage 621 and the output passage 623 into the input / output pipe 53. The cooling water on the discharge side flows from the input / output pipe 52 through the input passage 721 and the output passage 723 to the outlet 55. That is, the input / output pipe 53 functions as an input pipe, and the input / output pipe 52 functions as an output pipe.

[0069] The switching device 56 may be set to switch modes, for example, each time the vehicle's IG switch is turned on. That is, it may be set to switch between Mode 1 and Mode 2 for each trip of the vehicle. The switching device 56 may set the mode before the pump operates, that is, in a state where the cooling water is not flowing. Since the movable parts 64 and 74 are easy to drive in a state before the cooling water flows, power saving can be achieved.

[0070] The switching device 56 may permit energization of the solenoids 63 and 73 when the detection results of the detection units 65 and 75 satisfy a predetermined condition, and limit energization when the predetermined condition is not satisfied. For example, when the detection unit 65 does not detect the end portion 641E and the detection unit 75 detects the end portion 741E, the switching device 56 may apply a voltage to the solenoids 632 and 731. Similarly, when the detection unit 65 detects the end portion 641E and the detection unit 75 does not detect the end portion 741E, the switching device 56 may apply a voltage to the solenoids 631 and 732.

[0071] <Summary of the First Embodiment> According to the cooling device 50 of this embodiment, the heat exchange units 51 arranged in a stacked manner can cool the plurality of semiconductor elements 41 arranged along the flow path 511 from both sides. In addition, the cooling device 50 includes a switching device 56. The switching device 56 is configured to be able to switch between a first mode and a second mode. In the first mode, the cooling device 50 inputs cooling water into the flow path 511 via the input / output pipe 52 (first input / output pipe), and outputs the cooling water that has flowed through the flow path 511 via the input / output pipe 53 (second input / output pipe). In the second mode, the cooling device 50 outputs the cooling water that has flowed through the flow path 511 via the input / output pipe 52, and inputs cooling water into the flow path 511 via the input / output pipe 53.

[0072] The switching device 56 causes one of the input / output pipes 52 and 53 to function as an input pipe, and the other to function as an output pipe, and switches (alternates) the functions of the input pipe and the output pipe at a predetermined timing. Thereby, the bias of the heat load of the semiconductor element 41 can be suppressed. Ideally, the heat load of the semiconductor element 41 can be equalized. Therefore, the product life of the inverter 6 (power conversion circuit) composed of the plurality of semiconductor elements 41 can be extended.

[0073] As illustrated, the switching device 56 may include an input solenoid valve 60 and an output solenoid valve 70. The input solenoid valve 60 is connected to the input / output pipes 52 and 53, and selectively connects one of the input / output pipes 52 and 53 to the cooling water inlet 54. The output solenoid valve 70 is connected to the input / output pipes 52 and 53, and connects one of the pipes 52 and 53 different from the one selected by the input solenoid valve 60 to the cooling water outlet 55. By using the input solenoid valve 60 and the output solenoid valve 70 in this way, the connection between the input / output pipes 52 and 53 and the inlet 54 and the outlet 55, and the change (switching) of the connection can be facilitated. By using solenoid valves, the configuration can be simplified and the manufacturing cost can be reduced.

[0074] Also, after energizing the corresponding solenoids 63 and 73 and switching to the state of a predetermined mode, even if the energization is cut off, the positions of the movable parts 64 and 74 can be held by the fixing parts 66 and 76. That is, it is only necessary to energize at the timing of mode switching. Therefore, power saving can be achieved.

[0075] Although the example in which the input solenoid valve 60 has the solenoids 631 and 632 has been shown, it is not limited thereto. For example, it may have only the solenoid 631. By switching the direction of the voltage applied to the solenoid 631, even if the voltage is applied only to the solenoid 631, the movable part 64 can be driven in both the +Y direction and the -Y direction. The same applies to the output solenoid valve 70. The output solenoid valve 70 may have, for example, only the solenoid 731.

[0076] (Second Embodiment) This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be incorporated by reference. In the preceding embodiment, the movable part had a connecting part. Instead, it may be configured such that the movable part does not have a connecting part.

[0077] <Structure of Solenoid Valve> FIG. 12 shows the input solenoid valve of the switching device in the cooling device according to this embodiment. FIG. 12 corresponds to FIG. 8. FIG. 13 shows the output solenoid valve. FIG. 13 corresponds to FIG. 9. Both FIG. 12 and FIG. 13 show the state of mode 1. In FIG. 12 and FIG. 13, the +Y direction and the -Y direction are also shown. Also, the flow of the cooling water is indicated by an arrow.

[0078] Similar to the previous embodiment, the switching device 56 includes an input solenoid valve 60 and an output solenoid valve 70. The movable part 64 of the input solenoid valve 60 has two movable parts 641 and 642 and does not have a connecting part 643. The movable part 74 of the output solenoid valve 70 has two movable parts 741 and 742 and does not have a connecting part 743. The movable parts 641, 642, 741, and 742 are individually driven according to the voltage applied to the corresponding solenoids 631, 632, 731, and 732.

[0079] The input solenoid valve 60 further has recesses 644 and 645 and fixing parts 663 and 664. The recess 644 is provided at a position between the valve body 641V and the end part 641E in the movable part 641. The recess 645 is provided at a position between the valve body 642V and the end part 642E in the movable part 642. The fixing part 663 locks into the recess 644 in the state of mode 2 and holds the position of the movable part 641. The fixing part 664 locks into the recess 645 in the state of mode 1 and holds the position of the movable part 642. That is, the fixing part 661 holds the movable part 641 in the state of mode 1, and the fixing part 663 holds the movable part 641 in the state of mode 2. The fixing part 664 holds the movable part 642 in the state of mode 1, and the fixing part 662 holds the movable part 642 in the state of mode 2.

[0080] Similarly, the output solenoid valve 70 further has recesses 744 and 745 and fixing parts 763 and 764. The recess 744 is provided at a position between the valve body 741V and the end part 741E in the movable part 741. The recess 745 is provided at a position between the valve body 742V and the end part 742E in the movable part 742. The fixing part 763 locks into the recess 744 in the state of mode 1 and holds the position of the movable part 741. The fixing part 764 locks into the recess 745 in the state of mode 2 and holds the position of the movable part 742. That is, the fixing part 763 holds the movable part 741 in the state of mode 1, and the fixing part 761 holds the movable part 741 in the state of mode 2. The fixing part 762 holds the movable part 742 in the state of mode 1, and the fixing part 764 holds the movable part 742 in the state of mode 2. Other configurations are the same as those described in the previous embodiment.

[0081] <Modes 1 and 2> Next, based on FIGS. 12 to 15, Modes 1 and 2 will be described. FIG. 14 shows the input solenoid valve in the state of Mode 2. FIG. 15 shows the output solenoid valve in the state of Mode 2. FIG. 14 corresponds to FIG. 12, and FIG. 15 corresponds to FIG. 13. In FIGS. 14 and 15 as well, the +Y direction and the -Y direction are shown. Also, the flow of the cooling water is indicated by arrows.

[0082] The switching device 56 applies a positive voltage (positive electric voltage) to the solenoids 632 and 731 and a negative voltage (negative electric voltage) to the solenoids 631 and 732 at a predetermined timing to switch to the state of Mode 1.

[0083] By applying a negative voltage to the solenoid 631, the movable part 641 of the input solenoid valve 60 is driven in the +Y direction, for example, by an attractive force. By the driving, the locking of the concave part 644 by the fixed part 663 is released. The valve body 641V of the movable part 641 retreats with respect to the flow path 62 and opens the output path 622. By driving the end part 641E in the +Y direction, the fixed part 661 is pushed down, and the end part 641E passes through the fixed part 661 and is locked by the fixed part 661. In the locked state, the end part 641E is detected by the detection part 65.

[0084] By applying a positive voltage to the solenoid 632, the movable part 642 of the input solenoid valve 60 is driven in the +Y direction, for example, by a repulsive force. By driving the end part 642E in the +Y direction, the fixed part 662 is pushed down, and the end part 642E passes through the fixed part 662. The valve body 642V of the movable part 642 advances with respect to the flow path 62 and closes the output path 623. In this state, the concave part 645 is locked by the fixed part 664.

[0085] By applying a positive voltage to the solenoid 731, the movable part 741 of the output solenoid valve 70 is driven in the -Y direction, for example, by a repulsive force. Due to the driving of the end part 741E in the -Y direction, the fixed part 761 is pushed down, and the end part 741E passes through the fixed part 761. The valve body 741V of the movable part 741 advances with respect to the flow path 72 and closes the input path 721. In this state, the recess 744 is locked by the fixed part 763.

[0086] By applying a negative voltage to the solenoid 732, the movable part 742 of the output solenoid valve 70 is driven in the -Y direction, for example, by an attractive force. Due to the driving, the locking of the recess 745 by the fixed part 764 is released. The valve body 742V of the movable part 742 retreats with respect to the flow path 72 and opens the input path 722. Due to the driving of the end part 742E in the -Y direction, the fixed part 762 is pushed down, and the end part 742E passes through the fixed part 762 and is locked by the fixed part 762.

[0087] The switching device 56 may stop applying voltage to all the solenoids 63, 73, for example, when a predetermined time has elapsed since the start of voltage application. When the end part 641E is detected by the detection part 65, the voltage application to all the solenoids 63, 73 may be stopped. Since it is locked by the fixed parts 661, 664, 762, 763, the positions of the movable parts 64, 74 are held (maintained) even when the energization is cut off.

[0088] In mode 1, as shown in FIG. 12, the valve body 642V of the input solenoid valve 60 closes the output path 623, and as shown in FIG. 13, the valve body 741V of the output solenoid valve 70 closes the input path 721. Therefore, as in the previous embodiment, the input / output pipe 52 functions as an input pipe, and the input / output pipe 53 functions as an output pipe.

[0089] The switching device 56 applies a positive voltage (positive voltage) to the solenoids 631, 732 and a negative voltage (negative voltage) to the solenoids 632, 731 at a predetermined timing to switch to the state of mode 2.

[0090] By applying a positive voltage to the solenoid 631, the movable part 641 of the input solenoid valve 60 is driven in the -Y direction, for example, by a repulsive force. Due to the driving of the end part 641E in the -Y direction, the fixed part 661 is pushed down, and the end part 641E passes through the fixed part 661. The valve body 641V of the movable part 641 advances with respect to the flow path 62 and closes the output path 622. In this state, the recess 644 is locked by the fixed part 663.

[0091] By applying a negative voltage to the solenoid 632, the movable part 642 of the input solenoid valve 60 is driven in the -Y direction, for example, by an attractive force. Due to the driving, the locking of the recess 645 by the fixed part 664 is released. The valve body 642V of the movable part 642 retreats with respect to the flow path 62 and opens the output path 623. Due to the driving of the end part 642E in the -Y direction, the fixed part 662 is pushed down, and the end part 642E passes through the fixed part 662 and is locked by the fixed part 662.

[0092] By applying a negative voltage to the solenoid 731, the movable part 741 of the output solenoid valve 70 is driven in the +Y direction, for example, by an attractive force. Due to the driving, the locking of the recess 744 by the fixed part 763 is released. The valve body 741V of the movable part 741 retreats with respect to the flow path 72 and opens the input path 721. Due to the driving of the end part 741E in the +Y direction, the fixed part 761 is pushed down, and the end part 741E passes through the fixed part 761 and is locked by the fixed part 761. In the locked state, the end part 741E is detected by the detection part 75.

[0093] By applying a positive voltage to the solenoid 732, the movable part 742 of the output solenoid valve 70 is driven in the +Y direction, for example, by a repulsive force. Due to the driving of the end part 742E in the +Y direction, the fixed part 762 is pushed down, and the end part 742E passes through the fixed part 762. The valve body 742V of the movable part 742 advances with respect to the flow path 72 and closes the input path 722. In this state, the recess 745 is locked by the fixed part 764.

[0094] The switching device 56 may stop applying voltage to all the solenoids 63 and 73, for example, when a predetermined time has elapsed since the start of voltage application. When the end portion 741E is detected by the detection unit 75, the voltage application to all the solenoids 63 and 73 may be stopped. Since they are locked by the fixing portions 662, 663, 761, and 764, the positions of the movable portions 64 and 74 are held (maintained) even when the energization is cut off.

[0095] In Mode 2, as shown in FIG. 14, the valve body 641V of the input solenoid valve 60 closes the output passage 622, and as shown in FIG. 15, the valve body 742V of the output solenoid valve 70 closes the input passage 722. That is, the input / output pipe 53 functions as an input pipe, and the input / output pipe 52 functions as an output pipe. Other configurations are the same as those described in the previous embodiment.

[0096] <Summary of the Second Embodiment> As illustrated, the movable portion may be configured to be able to advance and retreat by switching the direction of energization to a single solenoid. For example, the movable portion 641 may be configured to be able to advance and retreat by switching the direction of energization to the solenoid 631. The movable portion 642 may be configured to be able to advance and retreat by switching the direction of energization to the solenoid 632. The movable portion 741 may be configured to be able to advance and retreat by switching the direction of energization to the solenoid 731. The movable portion 742 may be configured to be able to advance and retreat by switching the direction of energization to the solenoid 732.

[0097] According to this, the connecting portion 643 that connects the movable portions 641 and 642 and the connecting portion 743 that connects the movable portions 741 and 742 can be eliminated. Since an extra resistance component against the cooling water can be eliminated, for example, further power saving can be achieved.

[0098] (Third Embodiment) This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be incorporated. In the preceding embodiment, the mode was switched by energizing each of the input solenoid valve and the output solenoid valve. Instead of this, by providing a link mechanism, the mode may be switched by energizing the input solenoid valve and the output solenoid valve.

[0099] <Switching device> FIG. 16 shows a switching device in the cooling device according to this embodiment. FIG. 16 is a cross-sectional view taken along line XVI-XVI of FIG. 2. For convenience, the cooling water is shown omitted.

[0100] The switching device 56 includes an input solenoid valve 60 and an output solenoid valve 70, as in the preceding embodiment. The switching device 56 of this embodiment further includes a link mechanism 80. The link mechanism 80 has three links 81, 82, 83 and two joints 84, 85. The link 81 extends in the Y direction. One end of the link 81 is connected to a movable part 64, for example, an end part 642E. The link 82 extends in the Y direction. One end of the link 82 is connected to a movable part 74, for example, an end part 742E. The other end of the link 81 is connected to one end of the link 83 via the joint 84. The other end of the link 82 is connected to the other end of the link 83 via the joint 85.

[0101] The input solenoid valve 60 has a solenoid 63 and a detection unit 65. The output solenoid valve 70 does not have a solenoid 73 and a detection unit 75. Other configurations are the same as those described in the preceding embodiment (see FIGS. 2, 8, and 9).

[0102] <Modes 1 and 2> Next, based on FIGS. 17 to 20, Modes 1 and 2 will be described. FIG. 17 shows the input solenoid valve in the state of Mode 1. FIG. 17 corresponds to FIG. 8. FIG. 18 shows the output solenoid valve in the state of Mode 1. FIG. 18 corresponds to FIG. 9. FIG. 19 shows the input solenoid valve in the state of Mode 2. FIG. 20 shows the output solenoid valve in the state of Mode 2. In FIGS. 17 to 20 as well, the +Y direction and the -Y direction are shown. Also, the flow of the cooling water is indicated by arrows.

[0103] The switching device 56 applies a voltage (a positive-direction voltage) to the solenoid 632 at a predetermined timing to switch to the state of Mode 1. The movement of the movable part 64 is the same as the configuration shown in the previous embodiment. By applying a voltage to the solenoid 632, the movable part 642 of the input solenoid valve 60 is driven in the +Y direction. By the drive in the +Y direction, the end part 642E passes through the fixed part 662. The valve body 642V of the movable part 642 advances with respect to the flow path 62 and closes the output path 623. Along with the movement of the movable part 642, the movable part 641 is also driven in the +Y direction. The valve body 641V of the movable part 641 retreats with respect to the flow path 62 and opens the output path 622. By the drive in the +Y direction, the end part 641E passes through the fixed part 661 and is locked by the fixed part 661. In the locked state, the end part 641E is detected by the detection part 65.

[0104] When the movable part 64 moves in the +Y direction, the link 81 of the link mechanism 80 also moves in the +Y direction. When the link 81 moves in the +Y direction, the link 82 moves in the -Y direction. Therefore, the movable part 74 of the output solenoid valve 70 is also driven in the -Y direction. The valve body 742V of the movable part 742 retreats with respect to the flow path 72 and opens the input path 722. By the drive in the -Y direction, the end part 742E passes through the fixed part 762 and is locked by the fixed part 762. The movable part 741 is also driven in the -Y direction. By the drive in the -Y direction, the end part 741E passes through the fixed part 761. The valve body 741V of the movable part 741 advances with respect to the flow path 72 and closes the input path 721.

[0105] When a predetermined time has elapsed since the start of voltage application, for example, the switching device 56 stops applying voltage to the solenoid 632. Since the end portions 641E and 742E are locked by the corresponding fixed portions 661 and 762, the positions of the movable portions 64 and 74 are held (maintained) even when the energization is cut off.

[0106] In Mode 1, as shown in FIG. 17, the valve body 642V of the input solenoid valve 60 closes the output passage 623, and as shown in FIG. 18, the valve body 741V of the output solenoid valve 70 closes the input passage 721. That is, the input / output pipe 52 functions as an input pipe, and the input / output pipe 53 functions as an output pipe.

[0107] The switching device 56 applies a voltage (a positive-direction voltage) to the solenoid 631 at a predetermined timing to switch to the state of Mode 2. The movement of the movable portion 64 is the same as the configuration shown in the previous embodiment. By applying a voltage to the solenoid 631, the movable portion 641 of the input solenoid valve 60 is driven in the -Y direction. By being driven in the -Y direction, the end portion 641E passes through the fixed portion 661. The valve body 641V of the movable portion 641 advances with respect to the flow path 62 and closes the output passage 622. Along with the movement of the movable portion 641, the movable portion 642 is also driven in the -Y direction. The valve body 642V of the movable portion 642 retreats with respect to the flow path 62 and opens the output passage 623. By being driven in the -Y direction, the end portion 642E passes through the fixed portion 662 and is locked by the fixed portion 662.

[0108] When the movable portion 64 moves in the -Y direction, the link 81 of the link mechanism 80 also moves in the -Y direction. When the link 81 moves in the -Y direction, the link 82 moves in the +Y direction. Therefore, the movable portion 74 of the output solenoid valve 70 is also driven in the +Y direction. By being driven in the +Y direction, the end portion 742E passes through the fixed portion 762. The valve body 742V of the movable portion 742 advances with respect to the flow path 72 and closes the input passage 722. Along with the movement of the movable portion 742, the movable portion 741 is also driven in the +Y direction. The valve body 741V of the movable portion 741 retreats with respect to the flow path 72 and opens the input passage 721. By being driven in the +Y direction, the end portion 741E passes through the fixed portion 761 and is locked by the fixed portion 761.

[0109] When a predetermined time has elapsed since the start of voltage application, for example, the switching device 56 stops applying voltage to the solenoid 631. Since the end portions 642E and 741E are locked by the corresponding fixed portions 662 and 761, the positions of the movable portions 64 and 74 are held (maintained) even when the energization is cut off.

[0110] In Mode 2, as shown in FIG. 19, the valve body 641V of the input solenoid valve 60 closes the output passage 622, and as shown in FIG. 20, the valve body 742V of the output solenoid valve 70 closes the input passage 722. That is, the input / output pipe 53 functions as an input pipe, and the input / output pipe 52 functions as an output pipe.

[0111] <Summary of the Third Embodiment> As illustrated, the switching device 56 may have a link mechanism 80 connected to the movable portion 64 of the input solenoid valve 60 and the movable portion 74 of the output solenoid valve 70. By having the link mechanism 80, the movable portions 64 and 74 can be driven by applying voltage to one of the input solenoid valve 60 and the output solenoid valve 70. Thereby, for example, a configuration can be adopted in which the solenoid 73 and the detection unit 75 are excluded from the output solenoid valve 70. That is, the configuration can be simplified and the manufacturing cost can be reduced.

[0112] Although an example in which the output solenoid valve 70 does not have the solenoid 73 and the detection unit 75 has been shown, the present invention is not limited thereto. A configuration may be adopted in which the output solenoid valve 70 has the solenoid 73 and the detection unit 75, and the input solenoid valve 60 does not have the solenoid 63 and the detection unit 65.

[0113] Although an example in which the input solenoid valve 60 has solenoids 631 and 632 has been shown, it is not limited thereto. For example, it may have only the solenoid 631. By switching the direction of the voltage applied to the solenoid 631, even if a voltage is applied only to the solenoid 631, the movable part 64 can be driven in both the +Y direction and the -Y direction. The same applies to a configuration in which only the solenoid 73 is provided in the output solenoid valve 70.

[0114] (Fourth Embodiment) This embodiment is a modified example based on the preceding embodiment, and the description of the preceding embodiment can be incorporated by reference. In the preceding embodiment, the movable part was driven by energizing the solenoid to move the link mechanism. Instead, the movable part may be driven by moving the link mechanism.

[0115] <Switching Device> FIG. 21 shows a switching device in the cooling device according to this embodiment. FIG. 21 corresponds to FIG. 16. In FIG. 21, for convenience, the cooling water is shown omitted. In FIG. 21 as well, the +Y direction and the -Y direction are shown.

[0116] The switching device 56 includes an input solenoid valve 60, an output solenoid valve 70, and a link mechanism 80, similar to the configuration shown in the preceding embodiment (see FIG. 16). A motor 86 for driving the link mechanism 80 is disposed in the link mechanism 80. The motor 86 corresponds to a driving part. The motor 86 is disposed such that its rotation axis is substantially parallel to the X direction. The rotation axis of the motor 86 is connected to, for example, the link 83. When the motor 86 rotates in the positive direction indicated by the solid-line arrow, the link 81 moves in the +Y direction and the link 82 moves in the -Y direction. When the motor 86 rotates in the negative direction indicated by the broken-line arrow, the link 81 moves in the -Y direction and the link 82 moves in the +Y direction.

[0117] The input solenoid valve 60 does not have a solenoid 63. The output solenoid valve 70 does not have a solenoid 73 and a detection unit 75. Other configurations are the same as those described in the previous embodiment (see FIGS. 16 to 18).

[0118] <Modes 1, 2> Next, modes 1 and 2 will be described with reference to FIGS. 22 to 25. FIG. 22 shows the input solenoid valve in the state of mode 1. FIG. 22 corresponds to FIG. 8. FIG. 23 shows the output solenoid valve in the state of mode 1. FIG. 23 corresponds to FIG. 9. FIG. 24 shows the input solenoid valve in the state of mode 2. FIG. 25 shows the output solenoid valve in the state of mode 2. In FIGS. 22 to 25, the +Y direction and the -Y direction are also shown. Also, the flow of the cooling water is indicated by an arrow.

[0119] The switching device 56 energizes the motor 86 at a predetermined timing to switch to the state of mode 1 and rotates the motor 86 in the forward direction. When the motor 86 rotates in the forward direction as described above, the link 81 moves in the +Y direction. As a result, the movable part 642 of the input solenoid valve 60 is driven in the +Y direction. By the drive in the +Y direction, the end part 642E passes through the fixed part 662. The valve body 642V of the movable part 642 advances with respect to the flow path 62 and closes the output path 623. Along with the movement of the movable part 642, the movable part 641 is also driven in the +Y direction. The valve body 641V of the movable part 641 retreats with respect to the flow path 62 and opens the output path 622. By the drive in the +Y direction, the end part 641E passes through the fixed part 661 and is locked by the fixed part 661. In the locked state, the end part 641E is detected by the detection unit 65.

[0120] When the motor 86 rotates in the positive direction, the link 82 moves in the -Y direction. As a result, the movable part 742 of the output solenoid valve 70 is driven in the -Y direction. The valve body 742V of the movable part 742 retreats with respect to the flow path 72 and opens the input path 722. Due to the drive in the -Y direction, the end part 742E passes through the fixed part 762 and is locked by the fixed part 762. The movable part 741 is also driven in the -Y direction. Due to the drive in the -Y direction, the end part 741E passes through the fixed part 761. The valve body 741V of the movable part 741 advances with respect to the flow path 72 and closes the input path 721.

[0121] When a predetermined time has elapsed since the energization of the motor 86 started, for example, the switching device 56 cuts off the power supply to the motor 86. Since the end parts 641E and 742E are locked by the corresponding fixed parts 661 and 762, the positions of the movable parts 64 and 74 are held (maintained) even when the power supply is cut off.

[0122] In mode 1, as shown in FIG. 22, the valve body 642V of the input solenoid valve 60 closes the output path 623, and as shown in FIG. 23, the valve body 741V of the output solenoid valve 70 closes the input path 721. That is, the input / output pipe 52 functions as an input pipe, and the input / output pipe 53 functions as an output pipe.

[0123] The switching device 56 energizes the motor 86 at a predetermined timing to switch to the state of mode 2 and rotates the motor 86 in the negative direction. When the motor 86 rotates in the negative direction as described above, the link 81 moves in the -Y direction. As a result, the movable part 642 of the input solenoid valve 60 is driven in the -Y direction. The valve body 642V of the movable part 642 retreats with respect to the flow path 62 and opens the output path 623. Due to the drive in the -Y direction, the end part 642E passes through the fixed part 662 and is locked by the fixed part 662. Along with the movement of the movable part 642, the movable part 641 is also driven in the -Y direction. Due to the drive in the -Y direction, the end part 641E passes through the fixed part 661. The valve body 641V of the movable part 641 advances with respect to the flow path 62 and closes the output path 622.

[0124] When the motor 86 rotates in the negative direction, the link 82 moves in the +Y direction. As a result, the movable part 742 of the output solenoid valve 70 is driven in the +Y direction. By the drive in the +Y direction, the end part 742E passes through the fixed part 762. The valve body 742V of the movable part 742 advances with respect to the flow path 72 and closes the input path 722. Along with the movement of the movable part 742, the movable part 741 is also driven in the +Y direction. The valve body 741V of the movable part 741 retreats with respect to the flow path 72 and opens the input path 721. By the drive in the +Y direction, the end part 741E passes through the fixed part 761 and is locked by the fixed part 761.

[0125] When a predetermined time has elapsed since the start of energization of the motor 86, for example, the switching device 56 cuts off the energization of the motor 86. Since the end parts 642E, 741E are locked by the corresponding fixed parts 662, 761, the positions of the movable parts 64, 74 are held (maintained) even when the energization is cut off.

[0126] In mode 2, as shown in FIG. 24, the valve body 641V of the input solenoid valve 60 closes the output path 622, and as shown in FIG. 25, the valve body 742V of the output solenoid valve 70 closes the input path 722. That is, the input / output pipe 53 functions as an input pipe, and the input / output pipe 52 functions as an output pipe.

[0127] <Summary of the Fourth Embodiment> As illustrated, the switching device 56 may be disposed in the link mechanism 80 and have a motor 86 (drive unit) for operating the link mechanism 80. By the movement of the link mechanism 80 due to the rotation of the motor 86, the movable part 64 of the input solenoid valve 60 and the movable part 74 of the output solenoid valve 70 can be driven. Thereby, for example, a configuration can be adopted in which the solenoids 63, 73 are excluded from the input solenoid valve 60 and the output solenoid valve 70. That is, the configuration can be simplified and the manufacturing cost can be reduced.

[0128] (Other Embodiments) The disclosure in this specification, drawings, etc. is not limited to the illustrated embodiments. The disclosure includes the illustrated embodiments and modifications by those skilled in the art based thereon. For example, the disclosure is not limited to the combination of parts and / or elements shown in the embodiments. The disclosure can be implemented by various combinations. The disclosure can have additional parts that can be added to the embodiments. The disclosure includes those in which parts and / or elements of the embodiments are omitted. The disclosure includes the replacement or combination of parts and / or elements between one embodiment and another. The technical scope disclosed is not limited to the description of the embodiments. Some of the technical scopes disclosed are indicated by the description of the claims and should be construed to include all changes within the meaning and scope equivalent to the description of the claims.

[0129] The disclosure in the specification, drawings, etc. is not limited by the description of the claims. The disclosure in the specification, drawings, etc. includes the technical idea described in the claims and extends to more diverse and extensive technical ideas than the technical idea described in the claims. Therefore, various technical ideas can be extracted from the disclosure in the specification, drawings, etc. without being restricted by the description of the claims.

[0130] When an element or layer is referred to as "above", "connected to", "attached to", or "coupled with", it can be directly above, connected to, attached to, or coupled with another element or layer, and there may also be intervening elements or intervening layers. In contrast, when an element is referred to as "directly above", "directly connected to", "directly attached to", or "directly coupled with" another element or layer, there are no intervening elements or intervening layers. Other words used to describe the relationship between elements should be interpreted in a similar manner (e.g., "between" vs. "directly between", "adjacent" vs. "directly adjacent", etc.). As used in this specification, the term "and / or" includes any combination and all combinations of one or more of the associated listed items. That is, the description of A and / or B means at least one of A and B.

[0131] Spatially relative terms such as "inside", "outside", "back", "down", "lower", "up", "upper", etc. are used herein to facilitate the description of the relationship of one element or feature to another element or feature as illustrated. Spatially relative terms can be intended to encompass different orientations of the device during use or operation in addition to the orientation depicted in the drawings. For example, if the device in the figure is turned over, an element described as "under" or "beneath" another element or feature will be oriented "above" the other element or feature. Thus, the term "under" can encompass both upward and downward orientations. The device may be oriented in other directions (rotated 90 degrees or other orientations), and the spatially relative descriptors used in this specification are to be interpreted accordingly.

Description of Reference Numerals

[0132] 1... drive system, 2... DC power supply, 3... motor generator, 4... power conversion circuit, 5... smoothing capacitor, 6... inverter, 7... P line, 8... N line, 9... upper and lower arm circuits, 9H... upper arm, 9L... lower arm, 10... output line, 11... MOSFET, 12... diode, 20... power conversion device, 30... capacitor, 40... semiconductor device, 41... semiconductor element, 42... encapsulation, 421... one side, 422, 423... side surfaces, 43... wiring member, 44... main terminal, 45... signal terminal, 50... cooling device, 51... heat exchange section, 511... flow path, 52, 53... input / output pipes, 54... inlet, 55... outlet, 56... switching device, 57... cooling water, 58... connection path, 60... input solenoid valve, 61... valve body, 62... flow path, 621... input path, 622, 623... output paths, 63, 631, 632... solenoids, 64, 641, 642... movable parts, 641E, 642E... end parts, 641V, 642V... valve bodies, 643... connection part, 644, 645... recesses, 65... detection part, 66, 661, 662, 663, 664... fixing parts, 70... output solenoid valve, 71... valve body, 72... flow path, 721, 722... input paths, 723... output path, 73, 731, 732... solenoids, 74, 741, 742... movable parts, 741E, 742E... end parts, 741V, 742V... valve bodies, 743... connection part, 744, 745... recesses, 75... detection part, 76, 761, 762, 763, 764... fixing parts, 80... link mechanism, 81, 82, 83... links, 84, 85... joints, 86... motor

Claims

1. A plurality of heat exchange units (51) having a flow path (511) through which cooling water flows and stacked so as to cool a plurality of semiconductor elements (41) arranged along the flow path from both sides, A first input / output pipe (52) and a second input / output pipe (53) for inputting and outputting the cooling water to and from the flow path of each heat exchange unit, A first mode in which the cooling water is input into the flow path via the first input / output pipe and the cooling water that has flowed through the flow path is output via the second input / output pipe; and a second mode in which the cooling water that has flowed through the flow path is output via the first input / output pipe and the cooling water is input into the flow path via the second input / output pipe, and a switching device (56) configured to be switchable, A cooling device comprising the above.

2. The switching device is An input solenoid valve (60) connected to the first input / output pipe and the second input / output pipe and selectively connecting one of the first input / output pipe and the second input / output pipe to the inlet (54) of the cooling water, An output solenoid valve (70) connected to the first input / output pipe and the second input / output pipe and connecting the other one of the first input / output pipe and the second input / output pipe selected by the input solenoid valve to the outlet (55) of the cooling water, The cooling device according to Claim 1, having the above.

3. Each of the input solenoid valve and the output solenoid valve has a solenoid (63, 73) and a movable part (64, 74) that is driven by energizing the solenoid to switch the internal flow path of the valve, The cooling device according to Claim 2, wherein the movable part is configured to be able to move forward and backward by switching the direction of energization of a single solenoid.

4. The switching device has a link mechanism (80) connected to the movable part of the input solenoid valve and the movable part of the output solenoid valve, the cooling device according to Claim 2.

5. The switching device has a drive part (86) arranged in the link mechanism and for operating the link mechanism, the cooling device according to Claim 4.

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