JP2009106075A - Inverter unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inverter unit which can be manufactured in a simplified assembling process, and can be miniaturized by efficiently accommodating a plurality of components configuring an inverter circuit. <P>SOLUTION: The inverter unit 3 has a case 1 for accommodating a substrate 100 having an inverter circuit, and a case 2 for accommodating a substrate 200 having a control circuit of the inverter circuit. The main circuit substrate 100 and the control circuit substrate 200 have connectors 110, 150 and 210, 250 which protrude to the outside of the main substrate case 1 and the control substrate case 2 and are accommodated in each of the cases, and are accommodated so as to have a space allowing a coupling harness to be inserted between at least one substrate and the peripheral wall portion of the case for accommodating the substrate. The main substrate case 1 and the control substrate case 2 abut so that the substrate housed in one case can be covered with the other case, and fixed, and both the substrates are enclosed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an inverter device having a plurality of parts constituting an inverter circuit and a case for housing these parts.

  For example, in an inverter device for driving a motor with a large output, such as that used in a hybrid vehicle or an electric vehicle, the switching element that constitutes the inverter circuit generates a large amount of heat, so that it is required to cool the switching element appropriately. The Further, in order to be mounted on a vehicle or the like, it is required that the inverter device is housed and integrated in a case and the entire inverter device is miniaturized because of weight reduction and mounting space restrictions.

  Regarding such a technique, for example, the following Patent Document 1 discloses the following configuration of an inverter device. That is, the inverter device includes a heat sink plate that constitutes a heat sink, an inverter case that forms an inverter housing chamber, a control circuit board that is fixed to the top wall of the inverter case and outputs a pulse width modulation signal, and an inverter housing chamber And an inverter circuit that is fixed to the heat sink plate and generates a phase current based on a pulse width modulation signal output from the control circuit board. Here, the inverter circuit is disposed below the control circuit board, and includes a smoothing capacitor, a transistor module including a switching element, and the like. The smoothing capacitor and the transistor module are electrically connected by a bus bar. The transistor module is also connected to the connecting member via the bus bar. The connecting member is connected to the motor and supplies each phase current to the motor. Further, a current sensor that detects a current flowing through the connecting member is provided adjacent to the connecting member. In this inverter device, the heat sink plate is formed in a flat plate shape, and a plurality of heat radiating fins are formed to protrude from the lower surface thereof. A transistor module, a smoothing capacitor, a connecting member, a current sensor, and the like are mounted and fixed on the upper surface of the heat sink plate.

JP 09-182459 A

  However, in the inverter apparatus as described above, it is necessary to perform an operation of electrically connecting each of these parts by a bus bar after mounting a plurality of parts such as a transistor module and a smoothing capacitor on the heat sink plate at the time of manufacture. There is. This complicates the assembly process and requires parts layout and heat sink plate design that take into account the work space required to insert tools during such operations. There was a problem that had to be made. Further, when a wiring cable is used as a connecting means for connecting the above components, it is necessary to secure a space for accommodating the wiring cable, which causes the inverter device to become large.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to simplify the assembly process at the time of manufacture and to efficiently store and downsize a plurality of parts constituting the inverter circuit. An object of the present invention is to provide an inverter device that can be used.

In order to achieve the above object, the characteristic configuration of the inverter device according to the present invention is as follows:
A main circuit board having an inverter circuit;
It has a facing surface facing the main circuit board and a peripheral wall portion erected along the periphery of the facing surface, and at least surrounds the periphery of the main circuit board with the peripheral wall portion to store the main circuit board. A main board case;
A control circuit board having a control circuit for controlling the inverter circuit;
The control circuit board includes a facing surface facing the control circuit board and a peripheral wall portion erected along a peripheral edge of the facing surface, and the control circuit board is accommodated by surrounding the control circuit board at least by the peripheral wall section. A control board case,
A connecting harness for connecting the main circuit board and the control circuit board,
The main circuit board and the control circuit board have a connector that protrudes outside the main board case and the control board case and is housed in each case, and at least one of the board and the case in which the board is housed The connecting harness is stored with a space through which the connecting harness can pass,
The end face of the peripheral wall portion of the main board case and the end face of the peripheral wall portion of the control board case are fixed in contact with each other, and the main circuit board and the control circuit board are included.

  According to this characteristic configuration, it is possible to store both the boards without any gap with respect to the peripheral wall portion of the case, except for a space in which the connecting harness that connects the main circuit board and the control circuit board is stored. Therefore, the inverter device can be reduced in size by efficiently storing a plurality of components without providing a useless space in the case. Also, unlike the conventional method of assembling an inverter device in which components are sequentially assembled in a case and finally covered, an inverter device is assembled by abutting and fixing two cases containing both substrates. be able to. Therefore, the assembly process at the time of manufacture can be greatly simplified as compared with the conventional case, and the working efficiency is improved. Further, since the substrate is surrounded and protected by the peripheral wall portion, the substrate can be prevented from being damaged during manufacture. In addition, a connector connected to a device different from the inverter device by, for example, a wiring cable or the like protrudes to the outside of the case, so that workability in inserting and removing the wiring cable is ensured.

  Here, in the inverter device according to the present invention, the main circuit board is stored with a space through which the connection harness can pass between the main circuit board and the peripheral wall portion of the main board case at one of the four sides. It is preferable that the control circuit board is accommodated without a gap between the control board case and the peripheral wall portion of the control board case.

A heat generating component such as a power semiconductor is mounted on a main circuit board that has an inverter circuit for driving a motor and outputs a motor driving signal. When the heat generating component is cooled using the main board case as a heat sink, the surface of the main circuit board on which the heat generating component is mounted is stored facing the main board case. Usually, a connector or the like to which a connecting harness is connected is often a discrete component as well as a heat generating component, and is mounted on the same surface. Therefore, the connector also faces the main board case. However, if a space through which the connecting harness can pass is provided between the main board case and the main circuit board as in this feature configuration, the control circuit board and the main circuit board are connected to pass through this space. It can be connected well by the harness. As long as the control circuit board is stored with the surface on which the connector is mounted facing the main circuit board side, even if the control circuit board is stored without having a gap with the peripheral wall portion of the control board case, Good connection is possible with the connecting harness.
If there is a space through which the connecting harness can pass between one of the boards and the peripheral wall of the case in which the board is stored, the boards can be connected using the connecting harness. However, as in this feature configuration, by providing a space between the main board case and the main circuit board, it is possible to achieve both cooling of the heat-generating component and space saving.

The inverter device according to the present invention is
The main circuit board and the control circuit board have a connecting connector to which the connecting harness is connected, and the connecting connector has the same side in a state where the main circuit board and the control circuit board are included. It is mounted on the side of

  The main circuit board and the control circuit board are included in the inverter device with their board surfaces facing each other. According to this feature, the connector to which the coupling harness is connected is mounted on the same side with both the boards included. Therefore, the distance between the connectors mounted on both the boards is shortened, and the connecting harness can be easily routed.

The inverter device according to the present invention is
The main circuit board and the control circuit board have a first surface on which discrete components and surface mount components are mounted, and a second surface on which surface mount components are mounted and leads of the discrete components are soldered. ,
The main circuit board and the control circuit board are included with the first surface facing in the same direction.

  When a substrate is mounted as in this feature configuration, components of various heights are mounted on the first surface side, which is also generally referred to as a component surface. Therefore, it is difficult to uniquely define a clearance for suppressing interference with members other than the substrate. On the other hand, on the second surface side, which is generally called a solder surface, a low-profile component having a substantially constant height is mounted and a short cut discrete component lead protrudes. Therefore, a clearance for suppressing interference with members other than the substrate can be uniquely determined. If the main circuit board and the control circuit board are included with the first surface facing in the same direction, the first surface of one substrate faces the second surface of the other substrate. Since the clearance of the second surface can be regarded as a constant value, it is sufficient to satisfy the clearance of the first surface. When the first surfaces face each other, surfaces where it is difficult to set the clearance face each other, so that it becomes difficult to design for securing the clearance, and productivity is lowered. In order to make the design easier, if an extra clearance is provided, the volume of the inverter device is unnecessarily increased, which is not preferable. Further, when the second surfaces face each other, connecting connectors for connecting both substrates, which are generally discrete components, are back to back. As a result, in order to route the connecting harness, it is necessary to provide a space through which the connecting harness can pass between both the boards and the peripheral wall portion of the case in which the boards are stored. When both boards are included as in this feature configuration, it is sufficient to provide a space between the board and the case only for one of the boards, making it easy to secure clearance and routing the connecting harness. It becomes easy. Further, when the connecting connector is mounted on the same side with the main circuit board and the control circuit board included, the connecting connector is mounted on both boards in the same direction. Therefore, the terminal arrangement of the connector for connection mounted on both the boards becomes the same, and the connection harness can be configured by a straight harness. As a result, it is easy to grasp the terminal arrangement during design and production, and wiring errors and the like can be suppressed.

  Further, in the inverter device according to the present invention, the height of the peripheral wall of the main board case is set to be higher than at least the height of components mounted on the main circuit board, and the height of the peripheral wall of the control board case is The height is set higher than at least the height of a component mounted on the control circuit board.

  According to this feature, the main circuit board and the control circuit board are disposed at a position where the main circuit board and the control circuit board are retracted to the opposite surface side from the end surface of the peripheral wall portion. Thereby, since both the boards are surrounded and protected by the peripheral wall portion, breakage of the boards during manufacturing can be suppressed.

The inverter device according to the present invention is
The main circuit board outputs a motor drive signal for driving a motor. The connector includes a first connector for power supply on one side and a second connector for motor drive signal output on the opposite side of the one side. Prepared,
The control circuit board includes, as the connector, a third connector for power supply on one side where the first connector is provided in a state of being included in the inverter device, and the behavior of the motor is provided on the opposite side of the one side. A fourth connector for connection with a sensor to be detected is provided.

Since the main circuit board is a board having an inverter circuit, the main circuit board receives an input from a DC power supply, performs signal processing, and outputs an AC motor drive signal. If the first connector for power supply and the second connector for motor drive signal output are arranged on opposite sides, the components can be arranged and wired on the main circuit board along the circuit flow. In addition, since the power source such as a battery and the motor are usually arranged apart from each other, one connector can be arranged on the battery side, and the other connector can be arranged on the motor side, and wiring to the inverter device can be performed efficiently. Can do. Further, since the third connector for power supply of the control circuit board is also disposed on the same side as the first connector for power supply, wiring for supplying power can be efficiently performed. Also, a sensor that detects the behavior of the motor, such as a rotation detection sensor, is usually arranged in the vicinity of the motor. Therefore, when the fourth connector is disposed on the same side as the second connector, wiring to the inverter device can be performed efficiently.
In such an inverter device, for example, a control device that issues an external command for motor control and a control circuit board may communicate with each other to control the motor. Such a control device is often arranged near the battery rather than near the motor. Therefore, in such a case, it is preferable that the third connector is used for power supply and for communication with the control device because wiring for communication can be efficiently performed.

  In the inverter device according to the present invention, the protruding end surfaces of the first connector and the third connector are on the same surface, and the protruding end surfaces of the second connector and the fourth connector are on the same surface. It is characterized by being.

  According to this characteristic configuration, the end surfaces of the connectors are aligned on the same surface, so that the workability when inserting / removing the wiring cable into / from the connector is improved.

Further, the main board case and the control board case of the inverter device according to the present invention have a fastening portion that is provided at each of four corners and fastens both cases with bolts,
The first connector, the second connector, the third connector, and the fourth connector are arranged at a central portion of a side where the connector is provided,
The fastening portion is provided to protrude in a direction in which the first connector and the third connector protrude and in a direction in which the second connector and the fourth connector protrude.

  Since the protruding portions from the inverter device are gathered in the same direction, the fastening portion can be efficiently provided without increasing the exclusive space of the inverter device.

  Embodiments of the present invention will be described below with reference to the drawings, taking as an example the case where the present invention is applied to an inverter device for driving a motor with a large output, such as used in a hybrid vehicle or an electric vehicle. In the present embodiment, the inverter device is provided in the form of an inverter box containing a circuit board inside.

[Overview of inverter box]
FIG. 1 is an external view of an inverter box 3 according to the inverter device of the present invention. FIG. 2 is a cross-sectional view of the inverter box 3 in the longitudinal direction. The inverter box 3 has two cases indicated by reference numerals 1 and 2 in the drawing. One case indicated by reference numeral 1 is a case in which the main circuit board 100 on which a plurality of components constituting the inverter circuit are mounted is accommodated. Hereinafter, the main board case 1 is abbreviated. The other case indicated by reference numeral 2 is a case in which a control circuit board 200 on which a plurality of components constituting the control circuit are mounted is stored. Hereinafter, the control board case 2 is abbreviated. The main board case 1 and the control board case 2 are made of a metal such as aluminum having excellent thermal conductivity.

  FIG. 3 is a perspective view showing how the main circuit board 100 is stored in the main board case 1. FIG. 4 is a top view of the main circuit board 100. Among a plurality of components constituting the main circuit having the inverter circuit as the core, at least the switching element and the discrete component are mounted on the first surface on one side of the main circuit board 100, and are surface mounted components such as a chip resistor and a chip capacitor. Is mounted on the second side of the back side of the first side. Hereinafter, for convenience, the first surface is referred to as a reflow surface 101 (component surface), and the second surface is referred to as a flow surface 102 (solder surface). Note that some of the surface-mounted components such as chip resistors and chip capacitors may be mounted on the reflow surface. In FIG. 2, FIG. 3, and FIG. 4, surface mount components such as chip resistors and chip capacitors are omitted.

  The main circuit board 100 is arranged such that the reflow surface 101 faces a predetermined facing surface 10 inside the main substrate case 1 and an IPM (intelligent power module) 130 as a switching element contacts the facing surface 10. In the state, it is fixed to the main board case 1. Details will be described later.

  FIG. 5 is a perspective view showing how the control circuit board 200 is housed in the control board case 2. At least a chip IC and a discrete component among a plurality of components constituting the control circuit are mounted on the first surface on one side of the control circuit board 200, and surface mount components such as a chip resistor and a chip capacitor are mounted on the back surface of the first surface. Mounted on the second side. Hereinafter, for convenience, the first surface is referred to as a reflow surface 201 (component surface), and the second surface is referred to as a flow surface 202 (solder surface). Note that some of the surface-mounted components such as chip resistors and chip capacitors may be mounted on the reflow surface. In FIG. 5, surface mount components such as a chip resistor and a chip capacitor are omitted. As can be seen from FIG. 2, the component surface 101 of the main circuit board 100 and the component surface 201 of the control circuit board 200 in the assembled state in which the main substrate case 1 and the control substrate case 2 are integrated. A configuration is adopted that faces in the same direction (downward in FIG. 2).

  The control circuit board 200 is housed in the control board case 2 such that the flow surface 202 faces the facing surface 20 inside the control board case 2. Then, in the state where the back surface of the heating element (switching element) 221 mounted on the reflow surface 201 of the control circuit board 200, that is, the flow surface 202 side is in contact with the protruding seat portion 21 provided on the facing surface 20. 2 is fixed. Details will be described later.

[Outline of the circuit]
Here, an outline of a main circuit constructed on the main circuit board 100 and a control circuit constructed on the control circuit board 200 will be described. FIG. 6 is a block diagram schematically showing the configuration of the main circuit, and FIG. 7 is a block diagram schematically showing the configuration of the control circuit.

[Main circuit board]
First, the configuration of the main circuit will be described with reference to FIG. A motor drive circuit for driving the motor 4 is configured in the main circuit, and the core is a bridge circuit that configures an inverter. The main circuit includes a first connector 110 for power input to the main circuit, a power smoothing capacitor 120, an IPM 130, a current sensor 140, a second connector 150 for motor drive current output, and a control circuit board 200. And the connector 115 for connection. In the present embodiment, two independent motor drive circuits are configured on the main circuit board 100 so that the two motors 4 can be driven independently. The power input first connector 110 and the power smoothing capacitor 120 are commonly used by two motor drive circuits. The IPM 130, the current sensor 140, the motor drive current output second connector 150, Each of the motor drive circuits has an independent connection connector 115.

  The first connector 110 for two-terminal power input is connected to a power supply unit 6 such as a vehicle battery, and supplies high voltage DC power to the main circuit board 100. The power supply smoothing capacitor 120 is a high-voltage, large-capacity capacitor configured using a film capacitor, an electrolytic capacitor, or the like. In this embodiment, as shown in FIG. 3 and FIG. 4, a plurality of (six in this embodiment) capacitors of two motor drive circuits are used. The six capacitors are connected in parallel to function as one capacitor having a large capacity on each motor drive circuit, and stabilize the power supply voltage.

  The IPM 130 corresponds to a switching element mounted on the main circuit board 100 in the present embodiment. As will be described later, the IPM 130 has a module structure in which a plurality of elements are mounted on a metal base and integrated. In IPM 130, an inverter that converts direct current into three-phase alternating current is configured as a bridge circuit. As shown in FIG. 6, the bridge circuit includes six power transistors and flywheel diodes connected in parallel to the transistors. The power transistor can be of various structures such as a bipolar type, a field effect type, and a MOS type. In this embodiment, an insulated gate bipolar transistor (IGBT) is used. In addition, the IPM 130 includes peripheral circuits such as a driver circuit for driving the transistors of the bridge circuit, a short circuit prevention circuit, an undervoltage lockout circuit, an overcurrent prevention circuit, and an overheat prevention circuit. Thus, the IPM 130 is configured with most of the core functions of the main circuit.

  The IPM 130 is integrated with a peripheral circuit board on which an IGBT and a diode constituting an inverter are mounted on a metal base such as a copper base 131 and the peripheral circuit is configured. As shown in FIGS. 2 and 3, the copper base 131 is exposed from the package of the IPM 130 and can contact an external heat sink (cooling means). In the present embodiment, the main board case 1 functions as a heat sink, and the copper base 131 is brought into contact with the facing surface 10 of the main board case 1. At this time, silicon grease is applied between the copper base 131 and the facing surface 10 in order to increase the contact area and lower the thermal resistance. The main circuit board 100 is fixed to the main board case 1 in a state where the copper base 131 is disposed so as to be in contact with the facing surface 10 of the main board case 1. Although details will be described later, the main board case 1 is formed with heat radiation fins 31 and actively used as a heat sink.

  As shown in FIG. 6, the IPM 130 outputs three-phase motor drive currents of U phase, V phase, and W phase. These motor drive currents are output to the motor 4 via the motor drive current output second connector 150. The second connector 150 has three terminals corresponding to the U-phase, V-phase, and W-phase, each of which is a U-phase, V-phase, and W-phase stator of the motor 4 via a wiring cable (not shown). Connected with coil.

  A current having the same magnitude as the current (motor current) flowing in each phase of each stator coil flows through the output line of each phase of the motor drive current. Current sensor 140 detects a motor current on main circuit board 100. In the present embodiment, a current of two phases out of the three phases is measured by the current sensor 140. Since the three-phase motor currents are in an equilibrium state and their sum is zero, if the two-phase current of the three phases is detected, the remaining one-phase current can be obtained by calculation. In this embodiment, this calculation is performed in the control circuit.

  The connection connector 115 is a connector that connects the main circuit board 100 and the control circuit board 200 to each other via the connection harness 9. The IGBT constituting the inverter of the IPM 130 switches the inverter drive signal output from the control circuit by being input via the driver circuit. Inverter drive signals for driving the six IGBTs are transmitted from the control circuit board 200 to the main circuit board 100 via the connection harness 9 and the connection connector 115. Further, the sensor circuit power is supplied from the control circuit board 200 to the main circuit board 100 via the connection connector 115. This sensor power supply is used to drive the current sensor 140 described above. The detection result of the current sensor 140 is transmitted to the control circuit via the connection connector 115 and the connection harness 9.

  The main functions of the main circuit mounted on the main circuit board 100 have been described above. As described above, when the motor driving current is output from the input of the power supply voltage, the signal processing proceeds through the path of the first connector 110, the smoothing capacitor 120, the IPM 130, the current sensor 140, and the second connector 150. Referring to FIG. 4, along the progress of this signal processing, one direction parallel to the reflow surface 101 of the main circuit board 100, in this example, along the longitudinal direction of the main circuit board 100 having a substantially rectangular planar shape. From the left to the right in the figure, it can be seen that the first connector 110, the smoothing capacitor 120, the IPM 130, the current sensor 140, and the second connector 150 are arranged in this order.

  When the motor drive current is output from the inverter drive signal output from the control circuit, signal processing proceeds through the path of the connector 115 for connection, the smoothing capacitor 120, the IPM 130, the current sensor 140, and the second connector 150. Referring to FIG. 4, along the progress of this signal processing, one direction parallel to the reflow surface 101 of the main circuit board 100, in this example, along the longitudinal direction of the main circuit board 100 having a substantially rectangular planar shape. From the left to the right in the figure, it can be seen that the connecting connector 115, the smoothing capacitor 120, the IPM 130, the current sensor 140, and the second connector 150 are arranged in this order.

  Among the components mounted on the main circuit board 100, the component with the largest amount of heat generation is the IPM 130. The IPM 130 is disposed at the center of the main circuit board 100 where the highest heat dissipation effect can be obtained without hindering the signal flow.

[Control circuit board]
Next, the configuration of the control circuit will be described with reference to FIG. The control circuit board 200 includes a control circuit that controls the motor 4 in accordance with a command (external command) acquired by communication from an ECU (electronic control unit) 7 that controls the operation of the vehicle. The control circuit is configured with a control unit 240 that generates an inverter drive signal for driving the inverter of the main circuit to control the motor 4 as a core. In addition, the control circuit generates a drive voltage for driving the rotation detection sensor that detects the behavior of the motor and the current sensor 140 of the main circuit board 100 in order to perform feedback control according to the operation state of the motor 4. Regulator circuits 220 and 230 are also configured. The control unit 240 includes a microcomputer, a DSP (digital signal processor), and the like as core components.

  The control circuit includes a third connector 210 for power input from the power supply unit 6, a first regulator circuit 220 for generating ± 15V power, a second regulator circuit 230 for generating 5V power, a control unit 240, and a rotation. It has a fourth connector 250 for connection to the resolver 5 that functions as a detection sensor, a connector 215 for connection to the main circuit board 100, and a connector 225 for temperature sensor connection. Although the temperature sensor will be described later, as shown in FIG. 3, the temperature sensor 81 is installed in the main board case 1 as the temperature sensor assembly 8 and measures the temperature of the IPM 130.

  As described above, the two motor drive circuits are configured on the main circuit board 100 so that the two motors 4 can be driven independently. The control circuit board 200 also has two systems of control circuits corresponding to the two motor drive circuits of the two motors 4 and the main circuit board 100 except for a circuit that can be shared. For example, since the two resolvers 5 are provided corresponding to the two motors 4, two fourth connectors 250 are provided. In order to independently control the two motor drive circuits of the main circuit board 100, two connection connectors 215 are also provided. As described above, the connection connector 215 is connected to the connection connector 115 of the main circuit board 100 by the connection harness 9. The controller 240 is also functionally provided with two systems in order to control the two motor drive circuits of the main circuit board 100 independently. However, for example, one microcomputer may function as two systems of control units by a program, and two microcomputers are not necessarily provided on the control circuit board 200.

  The third connector 210 for power input is connected to the power supply unit 6 such as a battery of the vehicle, and supplies a power of, for example, a voltage of 12V to the control circuit board 200. As described above, the power supply unit 6 includes a battery having a higher voltage than the voltage 12V, but the voltage is converted by a DC-DC converter of the power supply unit 6 and the control circuit board 200 is supplied with a DC 12V power supply. The

  The first regulator circuit 220 generates ± 15 V power from the 12 V power supplied via the third connector 210. The first regulator circuit 220 includes a switching element such as a regulator IC or a power transistor as a core component. In this embodiment, a power transistor is used. The generated ± 15 V power is supplied to the current sensor 140 of the main circuit board 100 via the connection connector 215, and becomes a driving power source for the current sensor 140. Further, the power is supplied to the resolver 5 through the fourth connector 250 and becomes a drive power source of the resolver 250.

  Since the drive currents of the current sensor 140 and the resolver 5 are relatively large, elements having a large current capacity are used for the regulator IC and the power transistor that constitute the first regulator circuit 220. For this reason, the regulator IC and the power transistor become heat-generating elements that easily overheat (an example of heat-generating components), and heat dissipation means are also provided. As shown in FIG. 5, a protruding seat 21 is provided on the inner facing surface 20 of the control board case 2, and the mounting position of the power transistor 221 (heating component) mounted on the reflow surface 201 of the control circuit board 200 is provided. The projecting seat 21 comes into contact with the corresponding flow surface 202. Heat generated by the power transistor 221 is radiated to the control board case 2 through the control circuit board 200 and the protruding seat portion 21. That is, the control board case 2 functions as a heat sink. Details will be described later.

  The second regulator circuit 230 generates a 5V power supply from a 12V power supply supplied via the third connector 210. The second regulator circuit 230 is configured using a regulator IC or a power transistor. The generated 5V power supply serves as a drive power supply for the control unit 240. As described above, since the control unit 240 is configured using a microcomputer or the like, current consumption is relatively small. An element having a smaller current capacity than that of the first regulator circuit 220 is used for the regulator IC and the power transistor constituting the second regulator circuit 230.

  The control unit 240 communicates with the ECU 7 via a CAN (controller area network), receives a control command for the motor 4, and generates an inverter drive signal. Then, the control unit 240 outputs the generated inverter drive signal to the main circuit board 100 via the connection connector 215 and the connection harness 9. When generating the inverter drive signal, the control unit 240 uses the detection result of the current sensor 140, the detection result of the resolver 5, and the detection result of the temperature sensor 81 as feedback information. The temperature sensor 81 is configured using, for example, a thermistor, and measures the temperature of the contact portion between the IPM 130 and the main board case 1. The temperature sensor 81 is configured as a temperature sensor assembly 8 together with a locking portion 83 that is bolted to the main board case 1 and a connection harness 82 that connects the control circuit board 200 and the temperature sensor 81 (see FIG. 3). The connection harness 82 is connected to the temperature sensor connection connector 225 of the control circuit board 200. Then, the measurement result by the temperature sensor 81 is input to the control unit 240.

[Details and assembly procedure of inverter box]
As described above, the inverter box 3 includes the main circuit board 100, the main board case 1, the control circuit board 200, the control board case 2, the connection harness 9, the temperature sensor assembly 8, and fixing members such as bolts. The Hereinafter, a more detailed configuration of the inverter box 3 will be described along an assembling procedure.

[Assembly of circuit board]
Since the main circuit board 100 and the control circuit board 200 need to be mounted on a bare board, the assembly of the board will be described first.

  The main circuit board 100 is mounted on the reflow surface 101 by a known reflow process in which solder is applied to the reflow surface 101, surface-mounted components are disposed, and the reflow furnace is passed through. In addition, when the components mounted on the reflow surface 101 are only discrete components, a known flow process shown below is performed without performing the reflow process. In the present embodiment, the first connector 110 mounted on the reflow surface 101 of the main circuit board 100, the power supply smoothing capacitor 120, the IPM 130, the current sensor 140, the second connector 150, the connection connector 115, Since all of these are discrete components, the following flow process is performed without performing the reflow process.

  The flow process is performed as follows. First, surface-mounted components are placed on the flow surface 102 using an adhesive, and the adhesive is cured in a curing furnace. Subsequently, discrete components such as the first connector 110, the connecting connector 115, the capacitor 120, the IPM 130, the current sensor 140, and the second connector 150 are inserted from the reflow surface 101 side, and are passed through the flow furnace. As a result, the surface mount component on the flow surface 102 and the discrete component on the reflow surface are soldered. The soldering of the flow surface 102 is not limited to the full-surface flow welding as described above, and may be performed by combining reflow welding and spot flow welding. That is, after the surface mount component mounted on the flow surface 102 is reflow welded, the discrete component may be inserted from the reflow surface 101 side, and the lead of the discrete component may be spot flow welded. As described above, the main circuit board 100 as the intermediate assembly is assembled by performing the reflow process and the flow process.

  The control circuit board 200 is also assembled as an intermediate assembly by performing the reflow process and the flow process. The flow process of the control circuit board 200 is performed by spot flow welding. Since surface-mounted components are also mounted on the reflow surface 201 of the control circuit board 200, a reflow process is first performed. Since the surface-mounted component is also mounted on the flow surface 202 of the control circuit board 200, in this embodiment, the surface-mounted component on the flow surface 202 is also arranged on the substrate, and both surfaces are reflow welded simultaneously. At this time, as described in the description of the reflow process, the surface-mounted component on at least one surface facing downward in the reflow welding is bonded to the substrate. Discrete components mounted on the reflow surface 201 of the control circuit board 200 include a third connector 210, a connector for connection 215, a fourth connector 250, a capacitor 229, and the like (see FIG. 5). These discrete parts are soldered by spot flow welding. Since the capacitor 229 mounted on the control circuit board 200 has a smaller capacity than the capacitor 120 mounted on the main circuit board 100, surface mounted components may be used.

  Thus, the substrate in the present embodiment can be assembled completely independently of the assembly of the inverter box 3 by a simple process that is easy to automate. That is, since the assembly of each substrate can be divided, production lead time can be shortened. Further, as will be described later, a plurality of components constituting the main circuit and the control circuit are mounted on a substrate and integrated with each other, and these substrates are fixed to a case to form the inverter box 3. Accordingly, it is not necessary to attach each component to the case or a substrate attached to the case at the time of manufacture. Although such work is likely to be complicated manual work, according to this configuration, the assembly process at the time of manufacture can be greatly simplified. In addition, since the work space provided in the inverter box for attaching multiple parts to the case and electrical connection between the parts is not required, the multiple parts constituting the main circuit and the control circuit can be efficiently stored. Thus, the inverter box 3 can be reduced in size.

  When the main circuit board 100 and the control circuit board 200 are assembled, the main circuit board 100, the main board case 1, the control circuit board 200, the control board case 2, and the connecting harness, which are components and intermediate assemblies constituting the inverter box 3 9. All the temperature sensor assemblies 8 are provided. The inverter box 3 is assembled by assembling these components and the intermediate assembly. Hereinafter, the assembly of the inverter box 3 will be described in detail with reference to FIG. 8 which is a cross-sectional view showing the assembly of the substrate and the case and the assembly form of the two cases.

[Main board case assembly]
First, a process of assembling the main board case 1 and the main circuit board 100 to configure the main board case assembly 1A will be described. Prior to the description, the structure of the main board case 1 will be described.

  As described above, the main board case 1 is a case that has cooling means for the IPM 130 and houses the main circuit board 100. As shown in FIG. 3, the facing surface 10 (11 to 14) that the reflow surface 101 of the main circuit board 100 faces and the copper base 131 of the IPM 130 contacts is formed inside the main board case 1. The facing surface 10 (11 to 14) is formed in a step shape corresponding to the height of each component mounted on the reflow surface 101 of the main circuit board 100 so that components other than the IPM 130 do not contact. (See FIGS. 2, 3, and 8.) As apparent from FIG. 8 and the like, the height of the IPM 130 from the reflow surface 101, which is the mounting surface of the main circuit board 100, is the reflow of each of the first connector 110, the capacitor 120, the current sensor 140, and the second connector 150. It is lower than or substantially the same as the height from the surface 101. In the illustrated example, among these components, the height from the reflow surface 101 of the first connector 110 and the second connector 150 is the highest, and then the height of the capacitor 120 is the highest. The height of the IPM 130 from the reflow surface 101 is the lowest of these components, and the current sensor 140 is substantially the same height as the IPM 130. Accordingly, the facing surface 10 (11 to 14) has the highest region 12 facing the IPM 130 (close to the main circuit board 100) and the region 13 facing the current sensor 140 according to the height of each of these components. It is formed in a staircase shape so that the next highest region 11 facing the first connector 110 and the region 14 facing the second connector 150 are the lowest.

  As described above, these components are arranged in a first direction parallel to the reflow surface 101 of the main circuit board 100 (specifically, the longitudinal direction of the main circuit board 100 having a substantially rectangular planar shape). 1 connector 110, smoothing capacitor 120, IPM 130, current sensor 140, and second connector 150 are arranged in this order. Therefore, these components are arranged so that the center side of the board is low along the one direction of the main circuit board 100 and becomes higher toward both ends of the board. Therefore, the opposing surface 10 (11 to 14) is such that the substrate center side is low along the one direction of the main circuit board 100 according to the height of each component, and becomes lower toward the both ends of the substrate. It will be formed in a staircase shape. When the facing surface 10 is formed in a stepped shape in this way, the thickness of the region 12 facing the IPM 130 becomes thicker than the regions 11, 13, and 14 facing other components. For this reason, the heat capacity of the main substrate case 1 in the region 12 facing the IPM 130 is larger than those in the other regions 11, 13, and 14, and the IPM 130 has a structure suitable as a cooling means.

  The main substrate case 1 is provided with a plurality of heat radiation fins 31 erected on the opposing outer surface 30 on the back side of the opposing surface 10 as a cooling means. The plurality of radiating fins 31 have a high height from the opposing outer surface 30 in the back side portion of the region 12 where the IPM 130 of the opposing surface 10 is in contact, and the heights from the opposing outer surface 30 in the other regions 11, 13, and 14. It is formed low. Thereby, since the surface area of the radiation fin 31 can be increased in the vicinity of the IPM 130 that requires cooling, the IPM 130 can be cooled more efficiently.

  Further, the main board case 1 is formed so that the tips of the plurality of heat radiation fins 31 are located on the same plane. Moreover, the opposing outer surface 30 (the bottom of the trough formed by the adjacent radiating fins 31) that is the back side portion of the opposing surface 10 is formed in a stepped shape. Specifically, the opposing outer surface 30 is configured such that the back side portion (valley portion) of the region 12 with which the IPM 130 of the opposing surface 10 is in contact with the back side portions (valley portions) of the other regions 11, 13, 14. It is formed in a step shape so as to be positioned on the substrate 100 side.

  With this configuration, the height (depth) of the radiating fins 31 is made different for each of the regions 11 to 14 of the facing surface 10 while preventing the tip portions of the radiating fins 31 from being unevenly arranged. That is, by using the shape of the facing surface 10 of the main board case 1 corresponding to the height of the component mounted on the reflow surface of the main circuit board 100, the IPM 130 of the facing surface 10 contacts the heat radiation fin 31. The height from the opposing outer surface 30 is high in the back side portion of the region 12, and the height from the opposing outer surface 30 is low in the other regions 11, 13, and 14. As a result, the outer shape of the main board case 1 is made planar, and the surface area of the radiating fins 31 is increased in the vicinity of the IPM 130 that needs to be cooled while the IPM 130 is efficiently cooled in the vicinity of the IPM 130 that requires cooling. It becomes possible to do.

  A flange portion having a through hole 133 is formed on the side including the copper base 131 of the IPM 130. In a state where the IPM 130 is mounted on the main circuit board 100, a through hole 107 having a diameter larger than that of the through hole 133 of the IPM 130 is formed in a portion corresponding to the position of the through hole 133 of the main circuit board 100 (FIG. 3). , FIG. 8 etc.). In addition, when the IPM 130 is in contact with the region 12 of the opposing surface 10 of the main substrate case 1, a female screw 16 is formed in a portion corresponding to the position of the through hole 133 of the opposing surface 10. Silicon grease is applied to the surface of the copper base 131 of the IPM 130, the region 12 and the copper base 131 of the IPM 130 are brought into contact with each other, and the bolt 16B is inserted into the through hole 133 of the IPM 130 through the through hole 107 of the substrate. And the female screw 16 are fastened. Since the through hole 107 of the main circuit board 100 has a larger diameter than the seat of the bolt 16B, the bolt 16B passes therethrough. The through hole 133 of the IPM 130 is larger in diameter than the shaft diameter of the bolt 16B but smaller in diameter than the seat portion, so that the seat portion is locked to the flange portion. By fastening the bolt 16B and the female screw 16 in this state, the IPM 130 and the region 12 of the facing surface 10 are brought into close contact with each other. Silicon grease may be applied not to the surface of the copper base 131 of the IPM 130 but to the region 12 of the facing surface 10.

  As shown in FIG. 3, a groove-like recess 18 is formed in the region 12 of the facing surface 10 where the IPM 130 contacts. The recess 18 includes a columnar vertical hole 18a and a groove 18b extending from the side wall of the vertical hole 18a. A female screw 18c is formed at the bottom of the vertical hole 18a. The temperature sensor assembly 8 is accommodated in the recess 18 so as not to protrude from the facing surface 10. The temperature sensor assembly 8 has a temperature sensor 81 at one end portion of the connection harness 82 and an annular or Y-shaped locking portion 83 at the most distal end portion. A plug (not shown) that fits into the connection connector 225 of the control circuit board 200 is provided at the other tip (not shown) of the temperature sensor assembly 8. The temperature sensor assembly 8 is accommodated in the recess 18 by disposing the locking portion 83 in the vertical hole 18a and the temperature sensor 81 and the connecting harness 82 in the groove 18b. The temperature sensor assembly 8 is fixed to the main board case 1 by fastening the locking portion 83 with the female screw 18c and the bolt 18B in the vertical hole 18a. The other end portion having the plug of the temperature sensor assembly 8 is deflected to either side of the two connecting connectors 115 and extended to the outside of the main board case 1. Connection to the control circuit board 200 will be described later.

  With this configuration, the temperature sensor 81 can be disposed at a position where the temperature of the IPM 130 can be appropriately detected. Moreover, since it is not necessary to enlarge the area of the opposing surface 10 of the main board case 1 or the main circuit board 100 in order to arrange the temperature sensor 81, the inverter box 3 can be reduced in size.

  When the attachment of the temperature sensor assembly 8 to the main board case 1 is completed, the main circuit board 100 is then housed in the main board case 1. Prior to storing the main circuit board 100, one end of the connection harness 9 is connected to each of the two connection connectors 115 of the main circuit board 100. The connecting connector 115 is a straight-type connector, and requires a space in the vertical direction of the board surface together with the length of the plug of the connecting harness 9. However, as described above, the facing surface 10 of the main board case 1 is formed in a stepped shape so that parts other than the IPM 130 do not come into contact with each other. Since the connecting connector 115 is not a heating element, the main substrate case 1 may have a small thickness in the region 11 of the facing surface 10 facing the connecting connector 115, and a sufficient space is secured.

  Here, when an angle type connector is used as the connecting connector 115, a space is required in the horizontal direction of the board surface, that is, in the surface direction. Since it is practically impossible to mount components in the plug portion of the connecting harness 9 or the portion where the harness extending from the plug passes, it is necessary to make the main control board 100 unnecessarily large. However, by using a straight type connector as in this embodiment, the space of the main board case 1 can be efficiently utilized without causing such a problem.

  The main circuit board 100 is housed in the main board case 1 such that the reflow surface 101 on which the IPM 130 and other discrete components are mounted faces the facing surface 10 of the main board case 1. The first connector 110 and the second connector 150 include support recesses 111 and 151 on the surface opposite to the side mounted on the main circuit board 100, that is, the top surface of the connector (FIG. 8 and the like). On the other hand, support convex portions 51 and 52 are formed on the opposing surface 10 of the main substrate case 1 so as to protrude (FIGS. 3, 8, etc.). In a state where the main circuit board 100 is fixed to the main board case 1, the support convex portions 51 and 52 are inserted into the support concave portions 111 and 151 (FIGS. 2, 8 and the like).

  By having the supporting convex portions 51 and 52 and the supporting concave portions 111 and 151, positioning can be performed satisfactorily when the main circuit board 100 is set in the main board case 1. Further, in a state where the main circuit board 100 is fixed to the main board case 1, the connectors 110 and 150 are supported by both the main circuit board 100 and the supporting convex portions 51 and 52 of the main board case 1. Therefore, even when force is applied to the connectors 110 and 150 such as insertion and removal of the wiring cable, it is possible to suppress the electrical connection portion between the connectors 110 and 150 and the main circuit board 100 from being damaged.

  The main board case 1 includes a peripheral wall portion 50 erected along the periphery of the facing surface 10. The main board case 1 includes a plurality of fixed seats 55 having end surfaces 55a at positions where the end surfaces 50a of the peripheral wall portion 50 are retracted to the facing surface 10 side. These fixed seats 55 are formed with female screws and are provided at the four corners of the main board case 1, and the main circuit board 100 is placed on the fixed seats 55 at the corners. Through holes 105 are formed in the four corners of the main circuit board 100, and are fixed to the fixing seat 55 with bolts 55B. At this time, as described above, the IPM 130 and the region 12 of the facing surface 10 are fastened by the bolt 16B.

  Thus, the main circuit board 100 is arranged and fixed at an appropriate position in the peripheral wall portion 50 of the main board case 1. Here, it is preferable that the end surface 55 a of the fixed seat 55 is retracted at least by the thickness of the main circuit board 100 with respect to the end surface 50 a of the peripheral wall portion 50. If it does in this way, the main circuit board 100 will be arrange | positioned in the position retracted | retreated to the opposing surface 10 side rather than the end surface 50a of the surrounding wall part 50. FIG. As a result, the main circuit board 100 is surrounded and protected by the peripheral wall 50, and damage to the main circuit board 100 during manufacturing can be suppressed.

  As described above, the IPM 130 is disposed between the capacitor 120 and the current sensor 140 on the main circuit board 100. That is, the main circuit board 100 is disposed at substantially the center. The IPM 130 is fixed in contact with the region 12 of the facing surface 10 of the main substrate case 1. Therefore, the main circuit board 100 is supported by the main board case 1 at the four corners and the central part. As a result, it is possible to suppress the deflection of the main circuit board 100 without separately providing a support member such as a bracket.

  A general-purpose substrate is made of glass epoxy or the like and has a thickness of about 1.6 mm. When heat is applied to the substrate or heating / cooling is repeated, the substrate may be warped. In particular, the IPM 130 incorporating the IGBT generates a large amount of heat and gives a large stress to the substrate. Further, the IPM 130 has a metal base such as a copper base 131, and a ceramic material or the like is often used for the package, so that its mass is large. For this reason, when the IPM 130 is mounted on a substrate, there is a high possibility of causing warpage or the like. Therefore, conventionally, without being mounted on a substrate together with other components, wiring is performed after being mounted on a metal case, or wiring is performed after mounting on a single substrate. However, in this embodiment, the IPM 130 is mounted on the central portion of the substrate, and other components are also mounted on both sides thereof. In addition to the four corners of the substrate, the substrate is fixed over a wide range using the flat surface of the copper base 131 of the IPM 130 not only at the center. Therefore, the warpage of the substrate is suppressed well while making the assembly easy.

  FIG. 9 is a top view schematically showing a state in which the main circuit board 100 is fixed to the main board case 1. It can be easily understood that the main circuit board 100 is housed in the main board case 1 with very high space efficiency. However, a space 70 through which the connecting harness 9 that connects the main circuit board 100 and the control circuit board 200 passes is secured between the main circuit board 100 and the main board case 1. That is, the main circuit board 100 is stored with a space through which the connecting harness 9 can pass between the peripheral wall portion 50 of the main board case 1 on one of the four sides. In a state where the main circuit board 100 is attached to the main board case 1, the connecting harness 9 extends from the space 70 to the outside of the main board case 1. The connection harness 82 of the temperature sensor assembly 8 extends from either one of the two spaces 70 to the outside of the main board case 1. The main board case 1 that has been assembled so far is referred to as a main board case assembly 1A.

[Control board case assembly]
Next, a process of assembling the control board case 2 and the control circuit board 200 to configure the control board assembly 2A will be described. Prior to the description, the structure of the control board case 2 will be described.

  As described above, the control board case 2 has a cooling means for the power transistor 221 and accommodates the control circuit board 200. As shown in FIG. 5, the facing surface 20 that faces the flow surface 202 of the control circuit board 200 is formed inside the control board case 2. A protruding seat portion 21 is formed on the facing surface 20 so that the flow surface 202 of the control circuit board 200 contacts the partial surface of the facing surface 20. The protruding seat portion 21 has an area corresponding to the power transistor 221 and its peripheral portion, and two protruding screws 23 are also formed on the protruding seat portion 21.

  Two through holes 207 are formed in the control circuit board 200 at positions corresponding to the female screws 23, and the power transistor 221 is mounted on the reflow surface 201 between the through holes 207. The power transistor 221 is a surface mount component, and the lead of the power transistor 221 is not penetrated through the flow surface 202. Further, no through hole or the like is provided at the mounting position of the power transistor 221 except for the through hole 207. Further, a wiring pattern and component lands are not provided on the back surface side of the predetermined region, that is, the flow surface 202 side, and a resist mask is provided. That is, even if the projecting seat portion 21 contacts the flow surface 202 of the control circuit board 200, the circuit is not short-circuited.

  The control circuit board 200 comes into contact with the projecting seat portion 21 on the flow surface 202 and is fastened by the female screw 23 and the bolt 23B of the projecting seat portion 21 through a through hole 207 formed in the substrate. Therefore, this portion becomes a fixing portion that fixes the control circuit board 200 to the control board case 2 in the vicinity of the power transistor 221 (heat generating component). Further, the peripheral portion on the reflow surface side of the through hole 207 which is the seating surface of the bolt 23B, which constitutes the fixing portion, is subjected to a metal plating process with high thermal conductivity, so that the high thermal conductive material layer 207a is formed. Is formed. Many surface mounted power transistors have lower heat resistance than discrete power transistors, but the control board case 2 functions as a cooling means via the control circuit board 200 to improve heat resistance. Can be made.

  As shown in FIG. 5, the control board case 2 includes a peripheral wall portion 60 erected along the periphery of the facing surface 20. The control board case 2 includes a plurality of fixing seats 65 each having an end surface 65a at a position retracted closer to the facing surface 20 than the end surface 60a of the peripheral wall portion 60. These fixed seats 65 are formed with female screws and are provided at the four corners of the control board case 2. The control circuit board 200 is placed on these fixed seats 65 at the corners. Through holes 205 are formed in the four corners of the control circuit board 200, and are fixed to the fixed seat 65 with bolts 65B. At this time, the control circuit board 200 is also fixed to the protruding seat 21 formed on the facing surface 20 in the through hole 207 formed with the power transistor 221 interposed therebetween.

  The end surface 65a of the fixed seat 65 and the end surface 21a of the protruding seat portion 21 are formed on the same plane. Therefore, the control circuit board 200 is supported by five points of the four fixed seats 65 and the protruding seat portion 21. Here, as in the present embodiment, when the power transistor 221 is mounted in the central portion of the control circuit board 200, the control circuit board 200 is preferably supported by the central portion by the protruding seat portion 21. If comprised in this way, it will become possible to suppress the bending of the control circuit board 200, without providing separately supporting members, such as a bracket, for example. A general-purpose substrate is made of glass epoxy or the like and has a thickness of about 1.6 mm. When heat is applied to the substrate or heating / cooling is repeated, the substrate may be warped. However, since the substrate is fixed not only at the four corners of the substrate but also at the central portion, such warpage can be suppressed.

  As described above, the control circuit board 200 is arranged and fixed at an appropriate position in the peripheral wall portion 60 of the control board case 2. Here, it is preferable that the end surface 65 a of the fixed seat 65 is retracted at least by the thickness of the control circuit board 200 with respect to the end surface 60 a of the peripheral wall portion 60. In this way, the control circuit board 200 is disposed at a position where the control circuit board 200 is retracted to the facing surface 20 side with respect to the end surface 60 a of the peripheral wall portion 60. As a result, the control circuit board 200 is protected by being surrounded by the peripheral wall portion 60, and damage to the control circuit board 200 during manufacturing can be suppressed.

  Further, as in the present embodiment, the end surface 65a of the fixed seat 65 is retracted by the height of the component mounted on the reflow surface 202 in addition to at least the thickness of the control circuit board 200 with respect to the end surface 60a of the peripheral wall 60. It is preferable to do so. If it does in this way, control circuit board 200 will be arranged in the position retreated to the counter surface 20 side rather than end face 60a of peripheral wall part 60 including the components mounted on a board. As a result, the control circuit board 200 is protected by being surrounded by the peripheral wall portion 60, and damage to the control circuit board 200 and mounted components during manufacturing can be suppressed.

  Further, it is preferable that the end surface 65 a of the fixed seat 65 protrudes with respect to the opposing surface 20 at least as long as the length of the lead (terminal) of the discrete component protruding on the flow surface 202 of the control circuit board 200. The control board case 2 is made of a conductive material such as metal in consideration of thermal conductivity. Even if the opposing surface 20 is insulated, if the sharp lead ends of the discrete components come into contact with each other, a short circuit may occur. Therefore, it is preferable that the end surface 65a of the fixed seat 65 and the end surface 21a of the projecting seat portion 21 are set at positions projecting from the facing surface 20 rather than at least the lengths of the leads 225f and 229f of the discrete components.

  The control board case 2 to which the control circuit board 200 is fixed will be referred to as a control board case assembly 2A. FIG. 10 is a top view schematically showing the control board case assembly 2A. It can be easily understood that the control circuit board 200 is housed in the control board case 2 with very high space efficiency. That is, the control circuit board 200 is accommodated without a gap between the control circuit board case 2 and the peripheral wall 60. The connection connector 215 to which the connection harness 9 for connecting the main circuit board 100 and the control circuit board 200 is connected, and the connection connector 225 to which the connection harness 82 of the temperature sensor assembly 8 is connected are both in the control board case. In a state where the control circuit board 200 is fixed to 2, it is arranged on the opening side of the control board case 2.

  As described above, the main circuit board 100 is housed with the space 70 through which the connecting harness 9 can pass between the main circuit board 100 and the peripheral wall portion 50 of the main board case 1 on one of the four sides. The substrate 200 is accommodated without a gap between the peripheral wall portion 60 of the control substrate case 2. However, depending on the orientation in which both the boards 100 and 200 are accommodated in the inverter box 3, a space is provided between the control circuit board 200 and the control board case 2 to accommodate the control circuit board 200. The main board case 1 may be housed without a gap between the peripheral wall part 50 and the peripheral wall part 50. Further, a space may be provided between the main circuit board 100 and the peripheral wall part 50 of the main board case 1, and a space may be provided between the control circuit board 200 and the peripheral wall part 60 of the control board case 2. That is, the above embodiment is an example, and the main circuit board 100 and the control circuit board 200 have a space in which the connecting harness 9 can pass between at least one of the boards and the peripheral wall portion of the case in which the board is stored. It only has to be stored.

[Inverter box]
The main board case assembly 1A and the control board case assembly 2A contact the end face 50a of the peripheral wall portion 50 of the main board case 1 and the end face 60a of the peripheral wall portion 60 of the control board case 2 so that bolts are fastened at the fastening portions 59 and 69. Etc. are concluded. The inverter box 3 can be assembled very simply by fastening two cases each having a fixed substrate.

  Prior to fastening the two cases, the main circuit board 100 and the control circuit board 200 are connected by the connecting harness 9, and the plug of the temperature sensor assembly 8 is connected to the control circuit board 200. The procedure will be described below. First, the main board case assembly 1A and the control board case assembly 2A are arranged with the board facing upward. At this time, the assemblies 1A and 2A are arranged such that the connection connector 115 side (space 70 side) of the main circuit board 100 and the connection connector 215 side of the control circuit board 200 face each other. Then, the plug of the connection harness 9 extending from the space 70 is fitted into the connection connector 215 of the control circuit board 200. Similarly, the plug of the connection harness 82 of the temperature sensor assembly 8 extending from the space 70 is fitted into the connection connector 225 of the control circuit board 200.

  Subsequently, the control board case assembly 2A is overlaid on the main board case assembly 1A. Then, as described above, the end surface 50a of the peripheral wall portion 50 of the main board case 1 and the end surface 60a of the peripheral wall portion 60 of the control board case 2 are brought into contact with each other and fastened by the bolts 3B or the like at the fastening portions 59 and 69. In this way, the inverter box 3 as shown in FIGS. 1 and 2 is formed. A part of the fastening portion 59 of the main substrate case 1 is formed with a stepped portion 59a so that the hole diameter on the opening side is increased. In the present embodiment, stepped portions 59a are formed in the two fastening portions 59 on the diagonal line. The fastening portion 69 of the control board case 2 is formed to have the same hole diameter as the stepped portion 59a. The fastening portions 59 and 69 are positioned using a pipe-shaped knock pin that is locked at a stepped portion 59a of the fastening portion 59 of the main board case 1, and are fastened by a bolt 3B.

  The fastening part 59 of the main board case 1 and the fastening part 69 of the control board case 2 are provided at four corners. The fastening portions 59 and 69 are provided so as to protrude in the direction in which the first connector 110 and the third connector 210 protrude and in the direction in which the second connector 150 and the fourth connector 250 protrude. In this way, since the protruding portions from the inverter box 3 are gathered in the same direction, the fastening portions 59 and 69 can be efficiently provided without increasing the exclusive space of the inverter box 3.

  The control board case 2 is provided with an attachment portion 90 that further protrudes from the fastening portion 69 in the same direction as the fastening portion 69. The inverter box 3 is attached to the vehicle at the attachment portion 90. Note that the fastening portion 69 for fastening the main board case 1 and the control board case 2 and the mounting portion 90 may be provided so as to be shared.

  The connecting harness 9 includes a space 72 formed between the region 11 of the facing surface 10 of the main board case 1 and the board surface of the main circuit board 100, the inner surface of the peripheral wall portion 50 of the main board case 1, and the main circuit. The space 70 formed between the end face of the substrate 100 is used as a storage space, and is stored in the inverter box 3 satisfactorily (see FIGS. 2 and 9). Further, the connection harness 82 of the temperature sensor assembly 8 includes a groove-like recess 18 formed in the facing surface 10 of the main board case 1, the space 72, the space 70, the main circuit board 100, and the control circuit board 200. Is stored in the inverter box 3 satisfactorily as a storage space (see FIGS. 2 and 3).

  Thus, the inverter box 3 according to the present invention is constructed by assembling the sub-assemblies independently and assembling the whole using these sub-assemblies, so that it can be efficiently assembled. Conventionally, since the parts are sequentially assembled in the case, a lot of man-hours are required for the assembly, and it is necessary to provide a lot of useless clearance in the case in order to ensure the workability of the assembly. However, if the present invention is applied, the volume of the case can be reduced.

  As shown in FIGS. 1 and 2, the first connector 110 mounted on the main circuit board 100 and the third connector 210 mounted on the control circuit board have end surfaces on the same side. In addition, the second connector 150 mounted on the main circuit board 100 and the fourth connector 250 mounted on the control circuit board 200 have end faces on the protruding side on the same plane. Thereby, when the various cables are inserted into and removed from the inverter box 3, the work can be performed with the same surface as a reference. The third connector 210 and the fourth connector 250 provided in the control circuit board 200 are small because the current capacity may be smaller than the first connector 110 and the second connector 210 provided in the main circuit board 100, respectively. It is a connector. Therefore, the extension portions 208 and 209 are provided on the control circuit board 200 in order to align the protruding end surfaces, and the third connector 210 and the fourth connector 250 are mounted on the extension portions 208 and 209.

  The main board case 1 is a case fixed to the control board case so as to cover the reflow surface 201 side of the control circuit board 200. The control board case 2 is a case fixed to the main board case 1 so as to cover the flow surface 102 side of the main circuit board 100. In other words, the main board case 1 and the control board case 2 constitute an inverter box 3 that covers the other board and accommodates the two boards inside by fixing them together. Thereby, the main circuit board 100 and the control circuit board 200 can be housed inside the inverter box for protection. Further, the heat from the IPM 130 and the power transistor 221 conducted to one case is further conducted to the other case. Therefore, the cooling performance of switching elements such as the IPM 130 and the power transistor 221 can be further enhanced.

  Here, the outer case portion of the inverter box 3 is divided into the main board case 1 and the control board case 2, but various forms can be adopted with respect to the division ratio, that is, the position of the joint. It is preferable to examine this division ratio from the viewpoint of heat management and the viewpoint of packaging.

  First, an example of considering from the viewpoint of heat management will be described. The main board case 1 and the control board case 2 both store a board and serve as a heat sink. The heat generation amount of the heating element to be cooled is overwhelmingly larger in the IPM 130 that is cooled by the main board case 1. Therefore, as described above, the main board case 1 has a larger amount of metal than the control board case 2 and is formed with heat radiation fins 31 for increasing the surface area. Therefore, if the height of the peripheral wall portion 50 of the main substrate case 1 is further increased and the height of the peripheral wall portion 60 of the control substrate case 2 is decreased accordingly, the cooling performance of the main substrate case 1 can be further improved. . However, since the cooling performance of the control board case 2 is reduced accordingly, it is important to balance the two.

  Here, the opportunity for the main circuit board 100 and the control circuit board 200 to generate heat will be considered. A large current flows through the main circuit board 100 only when the motor is driven, and large heat is generated at that time. The control circuit board 200 generates heat even when the motor is stopped, and hardly generates heat even when the motor is driven. Since the main board case 1 and the control board case 2 are brought into contact with the end faces 50a and 60a of the peripheral wall portions 50 and 60, heat can be transferred between them although there is a thermal resistance.

  Therefore, the control board case 2 is formed by securing a metal amount having a heat capacity capable of sufficiently cooling the amount of heat generated by the control circuit board 200 by the control board case 2 alone. While the motor is stopped, heat transfer occurs with respect to the main board case 1, so that the control board case 2 can preserve much of its own heat capacity. When the motor is driven, large heat is generated in the main circuit board 100, so that the temperature of the main board case 1 as a heat sink rises. As a result, there is no heat transfer from the control board case 2 to the main board case 1, but there is no problem because the control board case 2 has a heat capacity capable of cooling the heat generation amount of the control circuit board 200 by itself. Further, since the main board case 1 is also used for cooling until the motor starts driving, the control board case 2 has a sufficient cooling power. Therefore, a large amount of heat transfer occurs from the main board case 1 to the control board case 2, and the temperature rise of the main board case 1 is mitigated. As a result, the cooling power of the main board case 1 is ensured for a long time.

  Thus, from the viewpoint of heat management, if the division ratio between the main board case 1 and the control board case 2 is set including the height of the peripheral wall portions provided in both cases 1 and 2, an inverter box having good cooling performance 3 can be configured.

  Next, an example in the case of considering from the viewpoint of packaging will be described. As described above, the inverter box 3 is configured by combining the main board case assembly 1A and the control board assembly 2A. When the peripheral wall portion of one case assembly is formed high and the other peripheral wall portion is formed so low, the other substrate or a component mounted on the substrate may be exposed beyond the peripheral wall portion. For this reason, when the main board case assembly 1A and the control board assembly 2A are matched, there is a possibility that the board and components mounted on the board may be damaged.

  Therefore, when determining the division ratio from the viewpoint of packaging, it is desirable that the peripheral wall satisfy the following conditions. That is, the height at which the end surface of the fixed portion of the substrate is provided so as to be retracted at least by the thickness of the substrate with respect to the end surface of the peripheral wall portion, and the end surface is surrounded and protected by the peripheral wall portion. It is desirable that the peripheral wall portion has. More preferably, the retraction amount from the end surface of the peripheral wall portion to the end surface of the fixed portion of the substrate may be set as follows. In other words, in addition to the thickness of the substrate, it is preferable to have at least a retraction amount corresponding to the height of the component mounted on the open surface side of the case. If it does in this way, the circumference | surroundings of the board | substrate and the mounting component of a board | substrate will be in the state protected by the surrounding wall part, and the failure | damage of the board | substrate and the mounting component at the time of manufacture can be suppressed.

  In the above-described embodiment, the division ratio is determined from both viewpoints of heat management and packaging.

  As described above, by applying the present invention, a structure capable of reliably cooling heat-generating parts such as switching elements, while simplifying the assembly process at the time of manufacture, and a plurality of parts constituting the inverter circuit It is possible to provide an inverter device that can be efficiently housed and miniaturized.

  The present invention can be applied to an inverter device for driving a motor having a large output, such as that used for a hybrid vehicle or an electric vehicle. Such hybrid vehicles, electric vehicles, and the like are required to save space in the internal structure. Therefore, as in the present invention, an inverter device that can efficiently accommodate and reduce the size of a plurality of components that constitute an inverter circuit is very useful. In addition, since the assembly process at the time of manufacturing the inverter device can be simplified, the production cost of a hybrid vehicle, an electric vehicle, or the like can be reduced.

External view of an inverter box according to the inverter device of the present invention Cross section of inverter box in longitudinal direction A perspective view showing how the main circuit board is stored in the main board case Top view of main circuit board The perspective view which shows the accommodation form of the control circuit board to a control board case Block diagram schematically showing main circuit configuration Block diagram schematically showing the configuration of the control circuit Disassembled sectional view in the longitudinal direction of the inverter box Top view of main board case after storing main circuit board Top view of the control board case after storing the control circuit board

Explanation of symbols

1: Main board case 2: Control board case 3: Inverter box (inverter device)
4: Motor 9: Connection harness 50: Peripheral wall portion 50a: End surface 70 of the peripheral wall portion: Space 60: Peripheral wall portion 60a: End surface of the peripheral wall portion 100: Main circuit board 101: Reflow surface (first surface)
102: Flow surface (second surface)
110: first connector 115: connector for connection 150: second connector 200: control circuit board 201: reflow surface (first surface)
202: Flow surface (second surface)
210: Third connector 215: Connector for connection 250: Fourth connector

Claims (8)

A main circuit board having an inverter circuit;
It has a facing surface facing the main circuit board and a peripheral wall portion erected along the periphery of the facing surface, and at least surrounds the periphery of the main circuit board with the peripheral wall portion to store the main circuit board. A main board case;
A control circuit board having a control circuit for controlling the inverter circuit;
The control circuit board includes a facing surface facing the control circuit board and a peripheral wall portion erected along a peripheral edge of the facing surface, and the control circuit board is accommodated by surrounding the control circuit board at least by the peripheral wall section. A control board case,
A connecting harness for connecting the main circuit board and the control circuit board,
The main circuit board and the control circuit board have connectors that protrude outside the main board case and the control board case and are housed in the respective cases, and at least one board and a case in which the board is housed The connecting harness is stored with a space through which the connecting harness can pass,
An inverter device configured to include the main circuit board and the control circuit board, wherein the end face of the peripheral wall part of the main board case and the end face of the peripheral wall part of the control board case are fixed in contact with each other.   The main circuit board is housed with a space through which the connection harness can pass between one side of the four sides and the peripheral wall portion of the main board case, and the control circuit board is stored in the control board case. The inverter apparatus of Claim 1 accommodated without having a clearance gap between peripheral walls. The main circuit board and the control circuit board have a connector for connection to which the connection harness is connected,
The inverter device according to claim 1, wherein the connecting connector is mounted on the same side in a state where the main circuit board and the control circuit board are included. The main circuit board and the control circuit board have a first surface on which discrete components and surface mount components are mounted, and a second surface on which the surface mount components are mounted and leads of the discrete components are soldered. ,
The inverter device according to claim 1, wherein the main circuit board and the control circuit board are included with the first surface facing in the same direction.   The height of the peripheral wall of the main board case is set to be higher than at least the height of components mounted on the main circuit board, and the height of the peripheral wall of the control board case is at least components mounted on the control circuit board The inverter apparatus as described in any one of Claims 1-4 set higher than height of. The main circuit board outputs a motor drive signal for driving a motor. The connector includes a first connector for power supply on one side and a second connector for motor drive signal output on the opposite side of the one side. Prepared,
The control circuit board includes, as the connector, a third connector for power supply on one side where the first connector is provided in a state of being included in the inverter device, and the behavior of the motor is provided on the opposite side of the one side. The inverter apparatus as described in any one of Claims 1-5 provided with the 4th connector for a connection with the sensor to detect.   The inverter device according to claim 6, wherein end surfaces on the protruding side of the first connector and the third connector are on the same surface, and end surfaces on the protruding side of the second connector and the fourth connector are on the same surface. The main board case and the control board case have fastening portions that are provided at four corners and fasten both cases with bolts,
The first connector, the second connector, the third connector, and the fourth connector are arranged at a central portion of a side where the connector is provided,
The inverter device according to claim 6, wherein the fastening portion is provided to protrude in a direction in which the first connector and the third connector protrude and in a direction in which the second connector and the fourth connector protrude.

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