JP5151257B2 - Electrical equipment and method for manufacturing the same - Google Patents

Description

  The present invention relates to an electric device and a manufacturing method thereof, and more particularly to an electric device having first and second bus bars for connecting a plurality of electric circuit portions in parallel and a manufacturing method thereof.

As a conventional electric device having first and second bus bars for connecting a plurality of electric circuit portions in parallel, for example, Japanese Patent Application Laid-Open No. 2005-328675 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2005-94882 ( The thing of patent document 2) is mentioned. Patent Documents 1 and 2 describe an electric device including a P bus bar and an N bus bar that connect a plurality of switching element groups in parallel. Patent Document 1 further describes providing a discharge resistor for discharging a charge charged in a capacitor connected between the P bus bar and the N bus bar.
JP 2005-328675 A JP 2005-94882 A

  Since heat is generated in the discharge resistance portion, it is necessary to provide a cooling structure. However, if the cooling structure for the discharge resistance portion is uniquely provided, the electric equipment becomes large.

  Moreover, it is preferable that the assembly | attachment property to the electric equipment of a bus bar is high from a viewpoint different from the above.

  In patent document 1, since the specific mounting structure of the discharge resistance part is not described, said problem cannot necessarily be solved sufficiently.

  This invention is made | formed in view of the above problems, and the objective of this invention is to provide the electric device which improved the assembly | attachment property of the bus-bar, suppressing the enlargement, and its manufacturing method. is there.

An electric device according to the present invention includes a plurality of electric circuit units, first and second bus bars that connect the plurality of electric circuit units in parallel, and a plurality of electric circuit units that are connected in parallel to store charges. And a chip resistor fixed to the first bus bar and the second bus bar so as to keep a gap between the first bus bar and the second bus bar at a predetermined gap, and discharging the charge stored in the charge storage unit And a resistance portion.

According to the above configuration, the gap between the first and second bus bars can be kept at a predetermined gap by the chip resistor , so that the insulation between the first and second bus bars can be ensured while suppressing an increase in inductance. it can. Here, the charge stored in the charge storage unit can be discharged using the chip resistors fixed to the first and second bus bars. And the heat_generation | fever in the case of the said discharge can be transmitted to the cooling structure for electric circuit parts via the 1st and 2nd bus bar. Therefore, it is not necessary to provide a unique cooling structure for the discharge resistance portion, and the increase in size of the electric device is suppressed. Further, since the first and second bus bars are integrated via the chip resistor , the assembling property of the first and second bus bars is improved.

In the electrical equipment, the discharge electric resistance section includes a plurality of chip resistors which are connected in parallel between the first and the second bus bar.

According to the above configuration, the redundancy of the discharge path is improved by connecting the chip resistors in parallel.
The electric device includes, as one example, a control device that controls the operation of the rotating electrical machine for driving the vehicle.

The method for manufacturing an electrical device according to the present invention includes a step of mounting a plurality of electrical circuit portions on a base portion, and a first and a second through a chip resistor while defining a predetermined gap between the first and second bus bars. A step of integrating the two bus bars, and a step of attaching the integrated first and second bus bars to the base portion and connecting the plurality of electric circuit portions in parallel.

According to the above method, since the gap between the first and second bus bars can be maintained at a predetermined gap by the chip resistance , it is possible to ensure the insulation between the first and second bus bars while suppressing an increase in inductance. it can. In addition, since the chip resistor is fixed to the first and second bus bars, the heat generated by the chip resistor can be transmitted to the cooling structure for the electric circuit portion via the first and second bus bars. Therefore, it is not necessary to provide a unique cooling structure for the chip resistor, and an increase in the size of the electric device is suppressed. Moreover, the assembly property of the first and second bus bars is improved by attaching the first and second bus bars integrated with each other through the chip resistor to the base.

In the above method , the first and second bus bars are integrated by a plurality of chip resistors connected in parallel between the first and second bus bars.

According to the above method, the redundancy of the discharge path is improved by connecting the chip resistors in parallel.
In the above method, as one example, the electric device includes a control device that controls the operation of the rotating electrical machine for driving the vehicle.

  ADVANTAGE OF THE INVENTION According to this invention, the assembly | attachment property of a bus bar can be improved, suppressing the enlargement of an electric equipment.

  Embodiments of the present invention will be described below. Note that the same or corresponding portions are denoted by the same reference numerals, and the description thereof may not be repeated.

  Note that in the embodiments described below, when referring to the number, amount, and the like, the scope of the present invention is not necessarily limited to the number, amount, and the like unless otherwise specified. In the following embodiments, each component is not necessarily essential for the present invention unless otherwise specified. In addition, when there are a plurality of embodiments below, it is planned from the beginning to appropriately combine the configurations of the embodiments unless otherwise specified.

  FIG. 1 is a diagram showing a configuration of a hybrid vehicle including an electric device according to one embodiment of the present invention.

  Referring to FIG. 1, hybrid vehicle 1 includes an engine 100, a motor generator 200 (210, 220), a power split mechanism 300, a differential mechanism 400, a drive shaft 500, and drive wheels 600L and 600R which are front wheels. A PCU (Power Control Unit) 700, a cable 800 (810, 820, 830), and a battery 900.

  As shown in FIG. 1, engine 100, motor generator 200, power split mechanism 300, and PCU 700 are arranged in engine room 2. Motor generators 210 and 220 and PCU 700 are connected by cables 810 and 820, respectively. PCU 700 and battery 900 are connected by a cable 830. A power output device including engine 100 and motor generators 210 and 220 is coupled to differential mechanism 400 through power split mechanism 300 and a speed reduction mechanism. Differential mechanism 400 is coupled to drive wheels 600L and 600R via drive shaft 500.

  Motor generators 210 and 220 are three-phase AC synchronous motor generators, and are driven by AC power received from PCU 700. Motor generators 210 and 220 are also used as generators, generate AC power by the power generation action, and output the generated AC power to PCU 700. Power split device 300 includes, for example, a planetary gear.

  PCU 700 converts the DC voltage received from battery 900 into an AC voltage and drives motor generators 210 and 220. PCU 700 charges battery 900 by converting the AC voltage generated by motor generators 210 and 220 into a DC voltage.

  FIG. 2 is a circuit diagram showing a configuration of a main part of PCU 700. Referring to FIG. 2, PCU 700 includes a converter 710, inverters 720 and 730, a control device 740, bus bars 750P and 750N, a discharge resistor unit 760, a filter capacitor C1, and a smoothing capacitor C2. Is done. Converter 710 is connected between battery 900 and inverters 720 and 730, and inverters 720 and 730 are connected to motor generators 210 and 220, respectively.

  Converter 710 includes power transistors Q1 and Q2, diodes D1 and D2, and a reactor L. Power transistors Q1, Q2 are connected in series and receive a control signal from control device 740 as a base. Diodes D1 and D2 are connected between the collector and emitter of power transistors Q1 and Q2, respectively, so that current flows from the emitter side to the collector side of power transistors Q1 and Q2. Reactor L has one end connected to power supply line PL1 connected to the positive electrode of battery 900, and the other end connected to a connection point of power transistors Q1 and Q2.

  Converter 710 boosts the DC voltage received from battery 900 using reactor L, and supplies the boosted boosted voltage to power supply line PL2. Converter 710 steps down the DC voltage received from inverters 720 and 730 to charge battery 900.

  Inverters 720 and 730 include U-phase arms 721U and 731U, V-phase arms 721V and 731V, and W-phase arms 721W and 731W, respectively. U-phase arm 721U, V-phase arm 721V, and W-phase arm 721W are connected in parallel between bus bar 750P and bus bar 750N. Similarly, U-phase arm 731U, V-phase arm 731V, and W-phase arm 731W are connected in parallel between bus bar 750P and bus bar 750N.

  U-phase arm 721U includes two power transistors Q3 and Q4 connected in series. Similarly, U-phase arm 731U, V-phase arms 721V and 731V, and W-phase arms 721W and 731W each include two power transistors Q5 to Q14 connected in series. Further, diodes D3 to D14 that flow current from the emitter side to the collector side are connected between the collector and emitter of each of the power transistors Q3 to Q14.

Intermediate points of the phase arms of inverters 720 and 730 are connected to phase ends of phase coils of motor generators 210 and 220, respectively. In motor generators 210 and 220, one end of three coils of U, V, and W phases is commonly connected to the midpoint.

  Filter capacitor C1 is connected between power supply lines PL1 and PL3, and smoothes the voltage level between power supply lines PL1 and PL3. The smoothing capacitor C2 is connected between the bus bars 750P and 750N, and smoothes the voltage level between the bus bars 750P and 750N.

  Inverters 720 and 730 drive motor generators 210 and 220 by converting a DC voltage from smoothing capacitor C2 into an AC voltage based on a drive signal from control device 740.

  Control device 740 calculates each phase coil voltage of motor generators 210 and 220 based on the motor torque command value from the computer, each phase current value of motor generators 210 and 220, and the input voltage of inverters 720 and 730, Based on the calculation result, a PWM (Pulse Width Modulation) signal for turning on / off the power transistors Q3 to Q14 is generated and output to the inverters 720 and 730.

  Control device 740 calculates the duty ratio of power transistors Q1 and Q2 for optimizing the input voltage of inverters 720 and 730 based on the motor torque command value and the motor rotation speed described above, and based on the calculation result. Thus, a PWM signal for turning on / off the power transistors Q1 and Q2 is generated and output to the converter 710.

  Further, control device 740 controls the switching operation of power transistors Q1 to Q14 in converter 710 and inverters 720 and 730 in order to charge battery 900 by converting AC power generated by motor generators 210 and 220 to DC power. To do.

  FIG. 3 is a diagram showing a mounting structure of U-phase arms 721U and 731U, V-phase arms 721V and 731V, and W-phase arms 721W and 731W included in the PCU. As shown in FIG. 3, the power transistor and the diode constituting each phase arm are provided in casing 770. A bus bar 750 (750P, 750N) is provided in the casing 770, and the phase arms are connected in parallel by the bus bar 750. The PCU 700 includes a cooling device 780 that cools the power transistor and the diode (semiconductor element).

  During the operation of the PCU 700, electric charges are accumulated in the smoothing capacitor C2. When the operation of the PCU 700 is stopped, control for discharging the electric charge accumulated in the smoothing capacitor C2 is performed. However, for example, in the event of a vehicle accident or failure, the above discharge control may not be performed. As described above, even when the discharge control cannot be performed, the smoothing capacitor C2 is configured to reduce the voltage to a predetermined voltage (for example, about 42 V or less) within a predetermined time (for example, within several minutes to several tens of minutes). In order to discharge the electric charge, the above-described discharge resistance portion 760 is provided.

  Since heat is generated in the discharge resistance portion 760, it is necessary to provide a cooling structure for cooling the discharge resistance portion 760. On the other hand, since there is a restriction on the space in the engine room 2, there is a demand for downsizing the PCU 700. In addition, there is a demand for improving the ease of assembling the bus bar 750 to the PCU 700.

  The inventor of the present application has devised a structure in which the pair of bus bars 750 and the discharge resistance portion 760 are integrated in response to the above request. The structure devised by the present inventor will be described with reference to FIGS. As shown in FIG. 4 (bus bar top view) and FIG. 5 (VV cross-sectional view in FIG. 4), the bus bar 750P and the bus bar 750N are composed of the PCU 700 by chip resistors 761, 762, and 763 constituting the discharge resistor 760. Integrated before assembly. The chip resistors 761, 762, and 763 are electrically connected in parallel between the bus bar 750P and the bus bar 750N. As shown in FIG. 4, the chip resistors 761, 762 and 763 are arranged in a matrix. The number of chip resistors (number of rows × number of columns) can be changed as appropriate.

  According to the structure shown in FIGS. 4 and 5, the gap between the bus bars 750P and 750N can be maintained at a predetermined gap (for example, about 1.5 mm to 2 mm) by using the thickness of the chip resistors 761 to 763. The insulation of the bus bars 750P and 750N can be ensured while suppressing an increase in inductance. Further, the charges stored in the smoothing capacitor C2 can be discharged using the chip resistors 761 to 763 fixed to the bus bars 750P and 750N. Then, heat generated in discharge resistance portion 760 can be transmitted to cooling devices 780 for U-phase arms 721U and 731U, V-phase arms 721V and 731V, and W-phase arms 721W and 731W via bus bars 750P and 750N. Therefore, it is not necessary to provide a unique cooling structure for the discharge resistance portion 760, and the enlargement of the PCU 700 is suppressed. Further, since the bus bars 750P and 750N are integrated via the chip resistors 761 to 763, the assembling property of the bus bars 750P and 750N to the casing 770 is improved.

  Further, the redundancy of the discharge path is improved by connecting the plurality of chip resistors 761 to 763 in parallel between the bus bars 750P and 750N.

  6 is a view showing one modification of the structure shown in FIGS. 4 and 5, and FIG. 7 is a sectional view taken along line VII-VII in FIG. As shown in FIGS. 6 and 7, the discharge resistance portion 760 may be configured to include chip resistors 761 and 762 provided so as to sandwich the bus bars 750P and 750N in the width direction. FIG. 8 is a diagram showing another modification of the structure shown in FIGS. As shown in FIG. 8, the bus bar 750 and the discharge resistor 760 may be assembled to the PCU 700 with the structure of FIGS. 4 and 5 rotated by 90 °.

  FIG. 9 is a diagram showing an example of the structure of the chip resistor 761. As shown in FIG. 9, the chip resistor 761 has positive and negative electrodes 761P and 761N. The electrodes 761P and 761N are connected to the bus bars 750P and 750N, respectively, by soldering or the like. The chip resistors 762 and 763 have the same structure as the chip resistor 761.

  The sizes of the chip resistor 761 shown in FIG. 9 are, for example, L1≈1.6 mm and L2≈3.2 mm. Here, when the resistance value of the entire discharge resistance unit 760 is set to 65 kΩ, the heat generation amount is set to 4 W, and the heat generation amount per chip resistor is set to 0.1 W, the number of chip resistors used is 4 / 0.1. = 40 (pieces) When these are all connected in parallel, the resistance value per chip resistor must be 65 (kΩ) × 40 = 2.6 (MΩ).

  Next, a method for manufacturing the PCU 700 will be described with reference to FIG. First, in step 10 (hereinafter abbreviated as “S10”), the semiconductor elements constituting the inverters 720 and 730 are mounted on the casing 770. In S20, the chip resistors 761 to 763 and the bus bars 750P and 750N are joined by solder connection or the like, and the bus bars 750P and 750N are integrated. In S30, the integrated bus bars 750P and 750N are attached to the casing 770, and the U-phase arms 721U and 731U, the V-phase arms 721V and 731V, and the W-phase arms 721W and 731W constituting the inverters 720 and 730 are connected in parallel. To do. Thereby, the mounting structure shown in FIG. 3 is obtained.

  The above contents are summarized as follows. That is, PCU 700 as an “electric device” according to the present embodiment includes a plurality of U-phase arms 721U and 731U, V-phase arms 721V and 731V and W-phase arms 721W and 731W as U-phases. A bus bar 750P as a “first bus bar” and a bus bar 750N as a “second bus bar” connecting the arms 721U and 731U, the V-phase arms 721V and 731V and the W-phase arms 721W and 731W in parallel, and the U-phase arms 721U and 731U The smoothing capacitor C2, which is connected in parallel with the V-phase arms 721V and 731V and the W-phase arms 721W and 731W and stores the charges, and the gap between the bus bars 750P and 750N are maintained at a predetermined gap. The “resistance element” fixed to the bus bars 750P and 750N The include chip resistors 761-763, and a discharge resistor 760 for discharging the charges stored in the smoothing capacitor C2.

  In addition, as shown in FIG. 10, the manufacturing method of PCU 700 according to the present embodiment is a casing 770 in which U-phase arms 721U and 731U, V-phase arms 721V and 731V, and W-phase arms 721W and 731W are used as “base portions”. Step (S10) for mounting on top, Step (S20) for integrating bus bars 750P and 750N via chip resistors 761 to 763 while defining a predetermined gap between bus bars 750P and 750N, and integrated bus bar Attaching 750P and 750N to casing 770 and connecting U-phase arms 721U and 731U, V-phase arms 721V and 731V, and W-phase arms 721W and 731W in parallel (S30).

  Although the embodiments of the present invention have been described above, the embodiments disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a figure which shows the structure of the hybrid vehicle containing the electric equipment which concerns on one embodiment of this invention. It is a circuit diagram which shows the structure of the principal part of PCU shown by FIG. It is a figure which shows the mounting structure of the electric element contained in PCU shown by FIG. It is a top view which shows an example of the connection structure of the bus bar contained in PCU shown by FIG. It is VV sectional drawing in FIG. It is a top view which shows the other example of the connection structure of the bus bar contained in PCU shown by FIG. It is VII-VII sectional drawing in FIG. It is sectional drawing which shows the further another example of the connection structure of the bus bar contained in PCU shown by FIG. It is a figure which shows an example of the discharge resistance contained in the electric equipment which concerns on one embodiment of this invention. It is a flowchart explaining the manufacturing method of the electric equipment which concerns on one embodiment of this invention.

Explanation of symbols

  1 Hybrid vehicle, 2 engine room, 100 engine, 200, 210, 220 motor generator, 300 power split mechanism, 400 differential mechanism, 500 drive shaft, 600L, 600R drive wheel, 700 PCU, 710 converter, 720, 730 inverter, 721U , 731U U-phase arm, 721V, 731V V-phase arm, 721W, 731W W-phase arm, 740 control device, 741 control board, 750, 750P, 750N bus bar, 760 discharge resistor section, 761, 762, 763 chip resistor, 761P, 761N electrode, 770 casing, 780 cooling device, 800, 810, 820, 830 cable, 900 battery, C1 filter capacitor, C2 smoothing capacitor, D1-D1 4 Diode, L reactor, PL1, PL2, PL3 power line, Q1-Q14 power transistor.

Claims (4)

A plurality of electrical circuit sections;
First and second busbars connecting a plurality of the electric circuit portions in parallel;
A charge storage unit connected in parallel with the plurality of electric circuit units to store charges;
A chip resistor fixed to the first bus bar and the second bus bar so as to keep a gap between the first bus bar and the second bus bar at a predetermined gap, and discharges the charge stored in the charge storage unit and a discharge resistor unit which,
The electric discharge resistor includes the plurality of chip resistors connected in parallel between the first and second bus bars . The electrical device according to claim 1 , wherein the electrical device includes a control device that controls an operation of a rotating electrical machine for driving a vehicle. Mounting a plurality of electric circuit portions on the base portion;
Integrating the first and second bus bars through a chip resistor while defining a predetermined gap between the first and second bus bars;
Attaching the integrated first and second bus bars to the base part and connecting the plurality of electric circuit parts in parallel ;
The method for manufacturing an electrical device , wherein the first and second bus bars are integrated by a plurality of the chip resistors connected in parallel between the first and second bus bars . The method of manufacturing an electrical device according to claim 3 , wherein the electrical device includes a control device that controls an operation of a rotating electrical machine for driving a vehicle.

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