JP2006042451A - Controller for driving electric motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inverter controller for driving an electric motor which mounts a plurality of semiconductor devices to a heat sink without screws and reduces man-hours for assembling. <P>SOLUTION: The controller for driving the electric motor is provided with a first groove 101 into which a plate spring 2 is inserted and collectively mounts the semiconductor devices to the heat sink 1 for cooling a plurality of the semiconductor devices 41, and a second groove 102 into which an insertion jig 3 is inserted and opens the plate spring when the semiconductor devices are mounted. The semiconductor devices are mounted and tightly contact the heat sink by a spring pressure by removing the insertion jig after the semiconductor devices are mounted. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

TECHNICAL FIELD OF THE INVENTION

  The present invention relates to a motor drive control device, and more particularly to a control device in which a plurality of power semiconductor elements such as MOSFETs are connected in parallel to drive a low-voltage AC motor, and more particularly to the structure of a plurality of power semiconductor elements and their radiators. Is.

Conventional technology

For driving a low-voltage AC motor such as an electric fork, a control device having an inverter circuit in which a plurality of power semiconductor elements such as MOSFETs are connected in parallel as a main component is used.
Most of these AC motors are three-phase AC, and the power unit of the control device is configured by an inverter circuit as shown in FIG. A block 4 in which a plurality of power semiconductor elements 41 shown in FIG. 2B are connected in parallel is connected in series on the + side and the − side to constitute one arm.

The three-phase is composed of three arms of U, V, and W phases, and the power semiconductor element 41 is driven ON / OFF based on a drive signal from a control circuit (not shown), and the control device generates a three-phase alternating current. Output.
In order to drive the power semiconductor element 41 on and off at a high frequency, a large electrolytic capacitor 7 is connected to the power source for lowering the power source impedance and further smoothing.

  Since the power supply requires a large current of several hundreds A to drive an electric fork at a low voltage of DC 100 V or less, a plurality of power semiconductor elements 41 of several tens of A are connected in parallel to the block unit 4 to radiate heat made of aluminum or the like. Wear on the body.

  FIG. 8 shows a conventional configuration of the power section of the control device for the three-phase AC motor. In FIG. 8B, 21 is a heat radiating body of the entire apparatus, 16 is a heat radiating body of each arm, 15 is a heat radiating body of the block unit 4 of the power semiconductor element 41, 22 is a power semiconductor element 41, its drive circuit and electrolytic capacitor. , 7 is an electrolytic capacitor, 14 is an insulating bush, 17 is an insulating sheet, and 20 and 19 are screws. A plurality of power semiconductor elements 41 are arranged in parallel for each block 4 as shown in FIG.

  In the conventional structure, the electrolytic capacitor 7 is mounted on the power board 22, and the insulating bush 14 is attached between the power board 22 and the radiator 15. Further, the insulating sheet 17 is inserted between the heat radiating body 15 and the heat radiating body 16, and the power substrate 22 and the heat radiating bodies 15 and 16 are assembled together with the screws 20. Thereafter, the power semiconductor element 41 is attached to the radiator 15 with the screw 19, and the power semiconductor element 41 is soldered to the power board 22. FIG. 9 shows a power circuit diagram of one arm and the electrolytic capacitor 7 attached to the radiator 16.

  In this structure, the attachment of the screw 19 and the soldering operation of the power semiconductor element 41 are performed separately for each arm after the power board 22 and the radiators 15 and 16 are assembled together.

  In this method, the number of screws is large, and the number of screwing and screwing steps is great. As an improvement measure, a method of caulking a power semiconductor element disclosed in Japanese Patent Application Laid-Open No. 2003-348702 has been proposed. Although this method can reduce the number of screws, the caulking direction is limited, so a plurality of power semiconductor elements cannot be attached to the heat dissipator for each block or arm for three phases, which leads to a reduction in manufacturing man-hours. Absent. In addition, three power boards are required independently, and the number of parts is not reduced.

Japanese Patent Laid-Open No. 9-246664 proposes a method of attaching a power semiconductor element with a spring. However, in the proposal, since the power semiconductor elements are individually spring-fastened, the number of springs required is the number of parts to be attached, the assemblability is poor, and the number of parts is large.
JP 2003-348702 A JP-A-9-246664

  SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems. Therefore, the invention according to claim 1 of the present application is directed to a radiator for cooling a plurality of semiconductor elements in a control device for driving an electric motor. In addition, a first groove for inserting a leaf spring for batch mounting of semiconductor elements and a second groove for inserting an insertion jig for opening the leaf spring when mounting the semiconductor element are provided. By pulling out, the semiconductor element is attached to the heat dissipating member with a spring pressure.

The invention according to claim 2 of the present application is characterized in that, in the above control device, the insertion jig has a semicircular structure in which the side surface of the cylindrical rod is cut, and the second groove is a semicircular groove.
Furthermore, the invention according to claim 3 of the present application is the above control device, further comprising an electrolytic capacitor, wherein the power semiconductor element and the electrolytic capacitor are mounted in a line on the same surface of the power substrate, the semiconductor element, the electrolytic capacitor, and the heat dissipation. The body is arranged in the same space.

Further, the invention according to claim 4 of the present application is characterized in that, in the control device, a cooling fan is provided in the space.
Furthermore, in the invention according to claim 5 of the present application, the control device drives the AC motor.
It is characterized by being.

  According to the first aspect of the present invention, the first groove into which the leaf spring for collectively mounting the semiconductor elements is inserted into the heat radiating body of each block also serving as an electrode, and the insertion jig for opening the leaf spring when the semiconductor element is mounted. By providing the second groove to be inserted and pulling out the insertion jig after mounting the semiconductor element, the semiconductor element can be mounted in close contact with each block by spring pressure to the heat sink, reducing the number of assembly steps. And can be assembled quickly and easily. Further, the number of parts can be reduced and the structure can be simplified.

  According to the invention of claim 2, since the insertion jig has a simple semicircular structure with the side surface of the cylindrical bar cut and the second groove is a semicircular groove, the opening and closing of the leaf spring is smooth and at any angle. Can be easily stopped. Furthermore, the manufacturing process of the insertion jig is easy.

  According to the invention of claim 3, since the semiconductor element and the electrolytic capacitor are arranged on the same surface of the power substrate, there is no structure on the solder surface. Since it can be cut, the man-hours are greatly reduced.

  Furthermore, according to the invention of claim 4, the semiconductor element and the electrolytic capacitor are mounted on the power board in a line on the same surface, and the semiconductor element, the electrolytic capacitor and the radiator are arranged in the same space, and the space is used for cooling. Since the fan, the space surrounded by the case, radiator and power board, that is, the tunnel space, can be realized, the cooling fan can cool the parts together and a great cooling effect can be expected.

  Furthermore, according to the invention of claim 5, by using the present invention for an inverter control device for driving an AC motor, it is possible to easily mount a large number of power semiconductor elements that are particularly complex to be mounted on a radiator. .

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described based on specific examples.
In FIG. 1, reference numeral 1 denotes a heat radiating element also serving as an electrode for each block on which a plurality of power semiconductor elements 41 are mounted, 2 is a leaf spring for mounting the power semiconductor elements 41, and 3 is an insertion jig.

  2A is an inverter circuit diagram of the control device, 4 is a power semiconductor element in a block unit in which a plurality of power semiconductor elements 41 are connected in parallel as shown in FIG. 2B, and 7 is an electrolytic capacitor for smoothing. It is.

  FIG. 3 shows an embodiment of a control device for driving a three-phase AC motor according to the present invention. FIG. 3 (a) is a plan view of the control device with the back cover 13 removed, and FIG. It is a front view of the removed control apparatus.

  In the figure, 5 is a power substrate on which a power semiconductor element 41, an electrolytic capacitor 7 and a drive circuit for the power semiconductor element 41 are mounted, 6 is a screw for attaching the power substrate 5 to the radiator 1, and 8 is a case also serving as a radiator. , 9 is an insulator for attaching the radiator 1 to the case 8, 10 is an insulating sheet for insulating the radiators 1 and 8, and 11 is a mounting screw for the insulator 9.

  Reference numeral 12 denotes a cooling fan (shown by three broken lines) attached in the case 8, and reference numeral 13 denotes a back cover. A control board on which a microcomputer or the like is mounted is present between the back cover 13 and the power board 22 but is not shown here.

  FIG. 4 is a layout diagram in which 6 blocks of 12 power semiconductor elements 41 and 32 electrolytic capacitors 7 are mounted on the power substrate 5 as a UVW three-phase inverter circuit.

  FIG. 5 is a front view (FIG. A) and a side view (FIG. B) showing the details of the heat dissipating body 1 in units of one block, a first groove 101 into which the leaf spring 2 is inserted, and a second in which the insertion jig 3 is inserted. A groove 102 is shown. The heat radiating body 1 is made of an aluminum stamping die, and its length is cut in accordance with the number of power semiconductor elements 41.

FIG. 6 is a detailed view of the leaf spring 2 and slits are provided so that independent spring pressure can be obtained even if the thickness of each power semiconductor element 41 varies.
FIG. 7 is a front view (FIG. A) and an end view (FIG. B) of the power semiconductor element 41 insertion jig 3, and the insertion portion shows a semicircular shape.

  Next, a method for assembling each part of the control device of the present invention will be described. An example will be described in which the power semiconductor element 41 is a non-insulating element and the radiator 1 also serves as a UVW or positive electrode.

First, as shown in FIG. 3, the radiator 1 is fixed to the bottom plate of the case 8 via the insulating sheet 10 by sandwiching the insulating plate 9 with screws 11, and the six radiators 1 are attached in an insulated state.
Thereafter, as shown in FIG. 1A, the leaf spring 2 is inserted in alignment with the first groove 101 of the radiator 1, and the insertion jig 3 is inserted along the second groove 102 of the radiator. Next, as shown in FIG. 1B, when the insertion jig 3 is turned 90 degrees, the leaf spring 2 is opened, and a clearance for the power semiconductor element 41 to enter between the radiator 1 and the leaf spring 2 is secured. The same operation is performed for the six blocks, and a gap is secured between each heat radiator 1 and the leaf spring 2. Then, the power board 5 is fitted into the power board 5 as shown in FIG. 3B with the component mounting surface of the power board 5 on which the power semiconductor element 41 and its drive circuit and the capacitor 7 are soldered in advance, with the component mounting surface facing. After the power board 5 is attached to the radiator 1 with the screws 6, the insertion jig 3 is pulled out from between the radiator 1 and the leaf spring. As shown in FIGS. 1C and 3B, the power semiconductor element 41 is obtained. Is pressed against the radiator 1 by a spring pressure and held. A front plate (not shown) of the case 8 is then attached.

By using the radiator 1 as a conductor of each electrode, the current flowing through the power substrate 5 can be reduced and the current can be increased.
As shown in FIG. 3, a power semiconductor element 41 that requires cooling and an electrolytic capacitor 7 are mounted on the same surface of the power substrate 5.

  In this way, each mounting component is mounted on the same surface on the power board, and there is no component on the solder surface opposite to the mounting surface, so automatic soldering, automatic cutting of the mounting component feet, etc. can be done A great reduction in man-hours can be expected.

  In this structure, as shown by a broken line in FIG. 3, by providing the cooling fan 12 in the space where the power semiconductor element 41 and the capacitor 7 are provided, a large cooling effect by forced cooling can be expected.

In the above description, the non-insulated power semiconductor element 41 has been described using the insulating sheet 10, but the present invention can be similarly applied to the case where the insulating power semiconductor element 41 is used.
Further, the present invention can also be applied to a control device using a large number of power semiconductor elements 41 such as a DC-DC converter.

It is explanatory drawing which shows the attachment point to the heat radiator of the power semiconductor element of this invention. It is the inverter circuit diagram of a three-phase control apparatus, the figure (a) is a general view, and the figure (b) is the partial figure. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a structural view of an embodiment of the present invention, where FIG. 1A is a plan view with a back cover removed, and FIG. 1B is a front view with a front plate removed. FIG. 4 is a layout diagram of components on the power board of FIG. 3. It is a figure which shows the heat radiator of FIG.1, 3, The figure (a) is a front view, The figure (b) is a side view. It is a front view of the leaf | plate spring of FIG. It is a figure which shows the insertion jig of FIG. 1, The figure (a) is a front view, The figure (b) is an end view. It is the conventional structural drawing, The figure (a) is a side view, The figure (a) is a front view. It is a circuit diagram of 1 arm of the power circuit of a three-phase inverter control apparatus.

Explanation of symbols

1 Radiator 2 Leaf Spring 3 Jig 4 Power Semiconductor Element Block
41 One power semiconductor element 5 Power board 6 Screw 7 Electrolytic capacitor 8 Case 9 Insulating bush 10 Insulating sheet 11 Screw 12 Fan 13 Cover 14 Insulating bush 15 and 16 Radiator 17 Insulating sheet 19 and 20 Screw 21 Radiator 30 Front plate

Claims (5)

  In a motor drive control device, a first groove into which a leaf spring for collectively mounting semiconductor elements is inserted into a radiator for cooling a plurality of semiconductor elements, and an insertion for opening the leaf spring when the semiconductor elements are mounted A control device for driving an electric motor, wherein a second groove for inserting a jig is provided, and the semiconductor element is attached in close contact with the heat dissipating member by spring pressure by pulling out the insertion jig after mounting the semiconductor element.   2. The control apparatus according to claim 1, wherein the insertion jig has a semicircular structure in which a side surface of the cylindrical rod is cut, and the second groove is a semicircular groove.   2. The control device according to claim 1, further comprising an electrolytic capacitor, wherein the power semiconductor element and the electrolytic capacitor are mounted in a line on the same surface of the power substrate, and the semiconductor element, the electrolytic capacitor, and the radiator are disposed in the same space. Control device characterized. 4. The control device according to claim 3, wherein a cooling fan is provided in the space.
apparatus. The control device is a control device having an inverter circuit that drives an AC motor as a main component.
A control device according to any one of claims 1 to 4.

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