JP2690551B2 - Drive circuit layout of three-phase motor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a drive circuit layout structure of a three-phase electric motor, and more particularly to a three-phase winding by converting a DC current of a DC power supply into a three-phase AC current by a semiconductor switching element. The present invention relates to a drive circuit layout structure for a three-phase electric motor that energizes a vehicle.

(Prior Art) In recent years, in engines for automobiles, etc., Japanese Patent Laid-Open No. 62-26
As described in Japanese Patent No. 8370 or Japanese Patent Laid-Open No. 63-202255, a three-phase electric motor is used as a starting electric motor, and the three-phase electric motor is integrated with an AC generator to start an engine and generate electric power. Various things are in practical use. For example, in the former Japanese Patent Laid-Open No. 62-268370, a rotor is provided with a permanent magnet for a field, a stator is provided with a three-phase winding, and this three-phase winding is used as a commutation circuit and a rectifier circuit. When operating as a starter motor, the output of the battery is converted into a three-phase alternating current by a commutation circuit to energize the three-phase winding, and when operating as a charging generator, the three-phase winding is connected. The three-phase AC output generated at is rectified by a rectifier circuit and taken out. This commutation circuit is a MOS
A semiconductor switching element such as FET is configured by connecting three-phase windings in a bridge shape. The semiconductor switching element is supported on both inner and outer surfaces of a cylindrical wall integrally formed with the housing, and the cylindrical wall is mounted on the rotor body. The fan is provided in the rotor main body so as to be cooled by being loosely inserted in the annular recess on the side surface of the rotor.

(Problems to be Solved by the Invention) However, in the conventional three-phase motor as described above, a cylindrical wall that is loosely inserted into the recess of the rotor is formed on the inner wall of the housing, and the semiconductor switching element is mounted on the cylindrical wall. In order to support the semiconductor switching elements, the work of attaching the semiconductor switching elements and connecting the semiconductor elements to each other or to the control circuit must be performed by inserting a hand into the housing by an operator, which is difficult and the connection is complicated. Then, there is a problem that there is a great possibility of interfering with the rotor.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a drive circuit layout structure for a three-phase electric motor that facilitates assembly work and simplifies wiring.

(Means for Solving the Problems) In the drive circuit arrangement structure for a three-phase electric motor according to the present invention, a rotating shaft is supported by a housing, and one of the rotating shaft and the housing has a magnetic pole for generating a field and the other has three magnetic poles. The phase winding is fixed, and the driving circuit connected to the three terminals of the three-phase winding is housed in the housing, and the driving circuit converts the direct current into the three-phase current to energize the three-phase winding. In the three-phase motor, the drive circuit has three terminals of the three-phase winding, the power source side semiconductor switching element interposed between the terminal and the power source, and the ground side semiconductor element interposed between the terminal and the ground. A switching element, the six semiconductor switching elements are individually supported on six substrates arranged point-symmetrically with respect to the rotation axis in the housing, and the semiconductor switching element is provided. The gist is that a control circuit for outputting a drive signal to the child is arranged at the center of the arrangement of each substrate.

(Operation) According to the drive circuit layout structure of the three-phase electric motor according to the present invention, since each semiconductor switching element is provided concentrically around the control circuit, the connection between each element and between each element and the control circuit is prevented. Along with shortening, the connection length can be matched. Since the semiconductor switching element is supported by the housing on the housing, the board and the element can be sub-assembled, and the element mounting work is easy.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 to 6 show a drive circuit arrangement structure of a three-phase electric motor according to an embodiment of the present invention as an engine starter / generator assembled integrally with a charging generator, and FIG. 1 shows power from the engine. An overall sectional view shown together with a transmission mechanism, FIG. 2 is an enlarged sectional view of an essential part, FIG. 3 is a sectional view taken along the line III-III in FIG. 2, and FIG. 4 is a sectional view taken along the line IV-IV in FIG. FIG. 5 (a) is a plan view of main components, FIG. 5 (b) is a sectional view taken along the line VV of FIG. 5 (a), and FIG. 6 is a partial circuit diagram.

In FIG. 1, E is an engine, T is a planetary gear type transmission, S is a starter generator (hereinafter referred to as a stag) in which a three-phase electric motor (starting electric motor) and a three-phase AC generator (charging generator) are integrated. The crankshaft 11 of the engine E is provided with a flange joint 11a at its end by a spline or the like and is connected to the transmission T via the flange joint 11a. The outer periphery of the flange joint 11a is supported by a ball bearing 12 on the crankcase of the engine E or the like.

The transmission T has a housing 13 fixed to the outer wall of the engine E and a set of planetary gear mechanisms P having a well-known sun gear 14, a planetary gear 15, a carrier 17, and a ring gear 16 accommodated therein. The ring gear 16 is restrained and released by an electromagnetic clutch 18 provided in the housing 13 to perform a shift operation. In the planetary gear mechanism P, the sun gear 14 is formed integrally with the output shaft 19, and the carrier 17 is connected to the above-described flange joint 11a via a bush 20 made of an elastic material such as rubber to connect the output shaft 19 and the carrier 17. Between the crankshaft 11
A one-way clutch 21 that allows only power transmission from the engine to the output shaft 19 is provided, and a plurality of locking holes (not shown) are formed in the ring gear 16 at regular intervals in the rotation direction. Although not clearly shown in the figure, the electromagnetic clutch 18 supports the housing 13 so that the locking claw is urged by a spring in a direction away from the locking hole of the ring gear 16 so as to be swingable, and the ignition key is operated when the engine is started. Accordingly, the locking claw is urged by the solenoid to be locked in the locking hole. A crank pulley 22 is fixedly provided on the output shaft 19 at an end portion protruding outside the housing 13,
A belt 25 is hung between the crank pulley 22 and a pulley 24 provided on the shaft 23 of the stag S so that power can be transmitted. In the transmission T, the ring gear 16 is restrained by an electromagnetic clutch 18 when the engine is started, and the power of the stag S is decelerated and transmitted to the crankshaft 11.

In the stag S, a housing 26 formed by joining two halves 27, 28 is attached to the upper part of the engine E, and a shaft 23 is rotatably supported by the housing 26. Each of the half bodies 27, 28 has a substantially bottomed cylindrical shape having a cylindrical wall 27a, 28a and an end wall 27b, 28b, and these half bodies 27, 28 are connected to an opening to define a mechanism chamber 29. ing. End wall 28 on half 28
A bearing hole 32a and a vent hole 33a are formed in b, an open hole 34a is formed in the cylindrical wall 28a close to the left side portion of a stator coil described later, and the half body 27 has a bearing hole 32b and an outside air hole in the end wall 27b. 33b
An open hole 34b is formed in the cylindrical wall 27a in proximity to the right side portion of a stator coil described later. Vent 3 in half 28
3a penetrates the end wall 28b to communicate a cooling air passage, which will be described later, with the mechanism chamber 29, and the shafts 23 are provided in the bearing holes 32a, 32b of the respective half bodies 28, 27.
Are rotatably supported via ball bearings.

The shaft 23 has a permanent magnet 35 having a large number of poles in the rotational direction fixed to the left end in the figure protruding from the end wall 28b of the half body 28, and at the right end in the figure protruding from the end wall 27b of the half body 27. The above-mentioned pulley 24 is fixedly mounted, and the rotor 36 is fixedly mounted in the middle portion of the mechanism chamber 29. The rotor 36 has two yoke halves
36a, 36b are fixed to the shaft 23, and these yoke halves 36a, 3b
The field coil 37 is held by 6b. The yoke halves 36a, 36b have their opposite ends assembled in a comb shape with each other, and a large number of magnetic poles are alternately generated in the circumferential direction on the outer periphery by the excitation of the field coil 37. These yoke halves
36a and 36b have cooling fans 38a and 3 on both sides in the axial direction.
8b is attached. The field coil 37 is connected to a slip ring 39 provided on the shaft 23 on the right side in the figure, and a voltage regulator arranged on the right side of the mechanism chamber 29 via a brush 41 that contacts the slip ring 39.
Connected with 40. As is well known, the voltage regulator 40 is connected to the battery and is connected to the field coil 37.
To control the field current flowing in the field coil 37.

In the housing 26, a stator 42 is fixedly installed on the inner wall of the mechanism chamber 29 outside the rotor 36. The stator 42 includes a plurality of starting coils 44 and a power-generating coil 44 (not shown in the figure, which are the same as the starting coils) alternately arranged in a circumferential direction on an annular yoke 43 fixed to the inner wall of the housing 26. The coils are distributed and wound, and the starting coil 44 and the power generating coil 44 are star-connected. The starting coil 44 is connected to a drive circuit, which will be described later, and the power generation coil 44 is connected to a rectifying circuit 45 arranged on the right side of the mechanism chamber 29 in the figure.
As the rectifier circuit 45, a known full-wave rectifier circuit including diodes is used, and the rectifier circuit 45 is connected to a battery via a relay (not shown). This relay has a contactor that responds to the operation of the ignition key to the start position, and cuts off the rectifier circuit 45 from the battery when the starting coil 44 is energized.

Further, the housing 26 is provided with a substantially cylindrical case 30 formed by joining two members to the left side surface of the end wall 28b in the drawing on the half body 28. In the case 30, the left side in the figure on the side of the end wall 28b opens the entire surface to define a circuit chamber 31 between the case 30 and the end wall 28b.
A mounting hole 30a and a plurality of outside air holes 30b are formed on the left side in the figure. In the circuit chamber 31, a cylindrical member 46 having a substantially cylindrical shape is arranged coaxially with the case 30, and six power modules 47 ₁ , 42 ₂ , 47 ₃ , 47 ₄ , 47 ₅ , are arranged outside the cylindrical member 46. 47 ₆ (hereinafter, represented by numbers without subscripts as necessary) are arranged.
The tubular member 46 is formed by separating the large tubular portion 46a and the small tubular portion 46b by a partition wall 46c, and the right end opening of the small tubular portion 46b in the drawing is the bearing 3 of the half body 28.
It is joined to the outer edge of 2a and surrounds the left end of the shaft 23,
The left end opening of the large cylinder portion 46a in the figure is opened as a mounting hole 30a. In this tubular member 46, a control circuit 48 is housed in a large tubular portion 46a, and a Hall element 49 is fixedly provided on the inner wall of the small tubular portion 46b in proximity to the permanent magnet 35 described above. The hall element 49 is connected to the control circuit 48 by a harness that penetrates the partition wall 46c,
The permanent magnet 35 detects the rotational position of the shaft 23 and outputs a detection signal. The control circuit 48 has a controller composed of a microcomputer, a drive circuit for driving the electromagnetic clutch 18 and a delay circuit for delaying the energization of the starting coil 44 with respect to the energization of the electromagnetic clutch 18. This control circuit
48 is connected to each power module 47 and an ignition key switch, etc., and determines the phase of the current to be supplied to the starting coil 44 based on the detection signal output by the wheel element 49 at the time of engine startup, and outputs a drive signal to the power module 47. Output.

The power module 47 is arranged concentrically inside the circuit chamber 31 outside the tubular member 46, and has both axial ends fixed to substantially annular holding members (partitioning members) 50 and 51, respectively. As shown in detail in FIG. 2, the holding member 50 on the right side of the drawing is formed by joining annular plates 50a and 50b made of an insulating material such as Bakelite and fixed to the end wall 28b of the half body 28. . Similarly, the holding member 51 on the left side of the drawing is formed by joining annular plates 51a and 51b made of an insulating material, and is fixed to the left end inner wall of the case 30 in the drawing. A bus bar 52, which will be described later, is sandwiched between the holding members 51 between the annular plates 51a and 51b, and the holding member 50 includes the annular plates 50a and 50b.
Three bus bars 53, 54, 55 described later are sandwiched between them. The power module 47 is configured by providing eight PMOS-FET bare chips (hereinafter abbreviated as FET) 57 in a substantially plate-like casing 56 having a relatively large thickness. The casing 56 is made of a material having excellent electric conductivity and thermal conductivity such as aluminum, and has a heat capacity corresponding to the heat generation amount of the eight FETs 57 in a predetermined time. The casing 56 extends in the direction orthogonal to the radial direction and in the axial direction, and both ends in the axial direction are fixed to the holding members 50 and 51 described above.
The seven casings 56 are arranged in a hexagonal tubular shape as a whole. Incidentally, 58a and 58b are knock pins for alignment.
In these casings 56, a plurality of cooling fins 60 are formed on the inner surface in the radial direction, and the inner surface defines a cooling air passage 59 extending axially with the above-mentioned tubular member 46. However, the cooling fins 60 project into the cooling air passage 59. Cooling air passage 59
The left end in the drawing is opened to the outside from the outside air hole 30b, and the right end in the drawing is opened to the mechanism chamber 29 via the ventilation hole 33a. As shown in FIG. 3, the cooling fins 60 project in parallel and stepwise toward the substantial center and extend in the axial direction.

As shown in FIGS. 5 (a) and 5 (b), the casing 56 has the above-mentioned eight FETs 57 fixed in two rows with four rows as one row on the outer surface in the radial direction. Strip electrode 61
However, the strip electrodes 62a and 62b with built-in resistors on the outside of each row are FET
It is arranged in parallel with 57 rows. FET57, casing 56
A drain electrode is formed on the joint surface with and is plated with nickel or the like and fixed to the casing 56 with solder or the like so as to be electrically conductive and thermally conductive. These FE
In T57, the source current is connected to the strip electrode 61, and the gate electrode is connected to the strip electrodes 62a and 62b depending on the column, and they are connected in parallel as a whole. The strip electrode 61 is a casing 56.
It is fixed via an insulating sheet 63 on top, as well as the strip electrodes.
62a and 62b are also fixed on the casing 56 via insulating sheets 64a and 64b. The casing 56 has a radially outer portion closed by a lid 65 made of a synthetic resin such as epoxy, and a silicon gel 66 is enclosed inside.

The above-mentioned six power modules 47 are connected to the starting coil 44 of the stator 42 as shown in FIG. 6, and constitute a drive circuit 67 for supplying a three-phase current to the starting coil 44. As is apparent from FIGS. 3, 4, and 6, three power modules 47 are arranged adjacent to each other in the upper part of the drawing.
₁ , 47 ₂ , 47 ₃ are interposed between the terminals of the starting coil 44 and the battery, and similarly, the power modules 47 ₄ , 47 ₅ , 47 ₆ arranged adjacently below are the starting coils 44. And the ground. Power module 47 ₁ , 47 ₂ , 47 ₃ is FET57
The drain, that is, the right end of the casing 56 is connected in parallel to the arc-shaped bus bar 52 sandwiched by the above-mentioned holding member 51 and connected to the battery via the bus bar 52, and the source of the FET 57, that is, the left end of the strip electrode 61, is the holding member. It is connected to the drains of the power modules 47 ₄ , 47 ₅ , 47 ₆ via the bus bars 53, 54, 55 sandwiched substantially parallel to 50, that is, the left end of the casing 56, and the gate of the FET 57, that is, the strip electrode 62.
The a and 62b are connected to the control circuit 48 by a harness or the like not shown. Also, three power modules 474,475,476
Is connected to the three terminals of the starting coil 44 by bus bars 68 (only one is shown in the figure) that penetrate the holding member 51 at the right end of the drain, that is, the casing 56, and the sources are respectively bus bars 69 (in the figure). (Only one is specified)
Is connected and installed at the left end of the half body 28, and the gate is connected to the control circuit 48. As clearly shown in FIG. 2, the bus bar 69 extends axially outward of the power module 47 and has a bent portion 69a formed at an intermediate portion thereof, and the bent portion 69a abuts on the lid 65. Holds the lid 65.

 Next, the operation of the embodiment will be described.

The stag S is used as a starting electric motor when the field coil 37 is connected to the battery via the voltage regulator 40 and is energized, and when the starting coil 44 of the stator 42 is energized with a three-phase current at the time of engine startup, and also the engine startup. After that, when the rectifying circuit 45 of the stator 42 is connected to the battery by a relay, the rectifying circuit 45 functions as a charging generator that generates power with the power generation coil 44.

When the engine is started, the electromagnetic clutch 18 of the transmission T is energized by operating the ignition key to the start position, and the starting coil 44 is energized when a predetermined time elapses after the electromagnetic clutch 18 is energized. To start. Therefore, in the transmission T, the locking claws of the electromagnetic clutch 18 are recessed into the locking holes of the ring gear 16 to restrain the ring gear 16, and then the stag S is driven as a starting electric motor, and the output of the stag S is changed to the transmission T. Is decelerated by and transmitted to the crankshaft 11 of the engine E, and the engine E is stag S.
It is started by Here, at the time of starting the engine, the drive circuit 67 energizes the starting coil 44 with a three-phase current by the switching action of the FET 57, and FE
Although T57 generates heat, the heat generated by this FET 57 is generated by the casing 56.
Therefore, the temperature rise of the FET 57 is suppressed.

Next, when the engine E is started, the transmission T is deenergized to the electromagnetic clutch 18 to release the ring gear 16, and the stag S is deenergized to the starting coil 44 to rectify the rectifier circuit 45. Is connected to the battery. For this reason,
The stag S is driven by the engine E via the transmission T to generate electric power, and rectifies the three-phase current generated in the power generation coil 44 by the rectifier circuit 45 and outputs the rectified current. Here, at the time of this power generation, the stag S and the shaft 23 are integrated with the cooling fan.
38a and 38b rotate, and as shown by the arrow in FIG. 1, the cooling fan 38a causes the cooling air to flow from the outside air holes 30b to the open holes 34a through the cooling air passages 59 and the ventilation holes 33a, and each power module.
47 and the left side of the coil 44 of the stator 42 in the figure are cooled, and the cooling air flows from the outside air hole 33b to the open hole 34b through the mechanism chamber 29 by the cooling fan 38b, so that the rectifier circuit 45, the voltage regulator 40, and the stator 42. The right side of the coil 44 in the figure is cooled. Therefore, the power module 47
And the coil 44 and the like of the stator 42 can be effectively cooled.
Furthermore, since the stator 42 and each power module 47 are separated by the holding member 51 and the end wall 28b, they do not affect each other thermally, and the power module 47 of the stag S is operated during operation as a charging generator. It is possible to prevent the temperature of the FET 57 from rising and to lower the temperature of the FET 57 when restarting the engine immediately after it is stopped.

On the other hand, in the stag S, each power module 47 has a FET 57.
Since the drains of the power modules 47 are conductively directly attached to the casing 56 and the power modules 47 are arranged concentrically around the control circuit 48, the wiring between the power modules 47 and between the power modules 47 and the control circuit 48 is performed. Can be simplified,
Furthermore, the busbars 52, 5 connecting between the power modules 47
Shortening of 3,54,55 and matching of resistance values can be achieved, and further, since the bus bars 53,54,55 are arranged in parallel, the risk of short circuit or the like can be extremely reduced.

Since each power module 47 can be pre-assembled with the FET 57 and connected to each other, the stag S
Is also easy to assemble, and since each power module 47 can be connected via the casing 56, wiring is also easy.

In the embodiment described above, the three-phase electric motor is exemplified as the starting electric motor that is integrally assembled with the charging generator,
It goes without saying that the present invention can be achieved even with a single three-phase motor.

(Effects of the Invention) As described above, according to the drive circuit layout structure of the three-phase electric motor according to the present invention, the drive circuit that outputs the three-phase alternating current to the three-phase winding has a bridge-like structure with respect to the terminals of the three-phase winding. Since the semiconductor switching elements connected to each other are concentrically arranged around the control circuit by the substrate, the connection length between each element and between the element and the control circuit can be shortened and matching can be achieved. Assembling work of the semiconductor switching element is also facilitated.

[Brief description of the drawings]

1 to 6 show an engine starting / charging device according to an embodiment of the present invention. FIG. 1 is an overall view, FIG. 2 is an enlarged cross-sectional view of an essential part, and FIG. 3 is FIG. III-III arrow sectional drawing, FIG. 4 is IV-IV arrow sectional drawing of FIG. 2, FIG. 5 (a)
Is a plan view of main parts, and FIG. 5 (b) is V in FIG. 5 (a).
FIG. 6 is a partial circuit diagram, which is a cross-sectional view taken along the line -V. E …… Engine S …… Starting generator (three-phase motor) 36 …… Rotor, 44 …… Starting coil 48 …… Control circuit, 56 …… Casing (board) 57 …… FET (semiconductor switching element) 59… … Cooling air duct, 60 …… Cooling fin 67 …… Drive circuit

Claims (5)

(57) [Claims] 1. A rotating shaft is supported by a housing, a magnetic pole for generating a field is fixed to one of the rotating shaft or the housing, and a three-phase winding is fixed to the other, and three of the three-phase windings are provided. A three-phase motor in which a drive circuit connected to a terminal is housed in a housing, and the drive circuit converts a direct current into a three-phase current to energize a three-phase winding. Each of the terminals is provided with a semiconductor switching element on the power source side interposed between the terminal and the power source and a semiconductor switching element on the ground side interposed between the terminal and the ground, and these six semiconductor switching elements are provided in the housing. A control circuit for individually supporting the six substrates arranged point-symmetrically with respect to the axis of the rotation axis and outputting a drive signal to the semiconductor switching element is arranged at the center of arrangement of the respective substrates. Driving circuit arrangement of a three-phase motor, characterized in that the. 2. The substrate is made of a conductive material and is supported by the housing via a holding member made of a non-conductive material, and the semiconductor switching element is supported by electrically connecting one terminal to the substrate. The drive circuit arrangement structure for a three-phase electric motor according to claim 1, wherein the terminals of the semiconductor switching element are connected through the substrate. 3. The three power source side semiconductor switching elements are arranged adjacent to one side and the three ground side semiconductor switching elements are arranged adjacent to the other side, and The drive arrangement circuit structure of the three-phase electric motor according to claim 1 or 2, wherein a semiconductor switching element on the power supply side and a semiconductor switching element on the ground side are connected in parallel for each terminal. 4. The substrate is made of a heat conductive material, and the semiconductor element is provided on the substrate so as to be able to conduct heat.
The two substrates are arranged in a substantially hexagonal tube shape to define a cooling air passage through which cooling air flows inside the center side.
4. The drive circuit layout structure for a three-phase electric motor according to claim 3. 5. The substrate according to claim 4, wherein the substrate supports the semiconductor switching element on an outer surface and has a heat radiating fin on an inner surface that projects into the cooling air passage. Of three-phase motor drive circuit.