JPH02266855A - Arrangement structure of drive circuit for three-phase motor - Google Patents

Abstract

PURPOSE:To shorten the connections between respective FETs and between the FETs and a controlling circuit as well as the matching of the lengths of connections between the same by providing respective semiconductor switching elements (FETs) concentrically around the controlling circuit. CONSTITUTION:In a starter generator S, the FETs 57 of respective power modules 47 are connected directly to a casing 56 through the drains thereof so as to be capable of conduction while respective power modules 47 are arranged concentrically around a controlling circuit 48. According to this method, connections between mutual power modules 47 and between respective power modules 47 and the controlling circuit 48 may be simplified while the lengths of bus bard 53-55, connecting between the power modules 47, may be shortened and the values of resistance of the same may be matched.

Description

Detailed Description of the Invention (Industrial Application Field) This invention relates to a drive circuit arrangement structure for a three-phase motor, and in particular, to a three-phase motor drive circuit that converts the DC current of a DC power source into a three-phase AC current using a semiconductor switching element. This invention relates to a drive circuit arrangement structure for a three-phase motor that conducts electricity.

(Prior art) In recent years, for engines such as automobiles, Japanese Patent Application Laid-Open No. 62-2
As described in Publication No. 68370 or Japanese Unexamined Patent Publication No. 83-202255, a three-phase motor is used as the starting motor, and this three-phase motor is integrated with an alternator to start the engine and generate electricity. Various things are put into practical use. For example, in the former Japanese Patent Application Laid-open No. 62-268370, a permanent magnet for field is provided in the rotor, a three-phase winding is provided in the stator, and this three-phase winding is used as a commutation circuit and a rectification circuit. When operating as a starting motor, the battery output is converted to three-phase alternating current by a commutation circuit and energized to the three-phase winding, and when operating as a charging generator, the three-phase winding is The three-phase alternating current output produced by the converter is rectified by a rectifier circuit and extracted. This commutation circuit is constructed by connecting semiconductor switching elements such as MOS FETs in a bridge shape around a three-phase winding. The cylindrical wall is loosely inserted into an annular recess on the side surface of the rotor body, and is cooled by a fan provided in the rotor body.

(Problem to be Solved by the Invention) However, in the conventional three-phase electric 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 a semiconductor switching element is mounted on the cylindrical wall. To support the housing, an operator must insert his or her hand into the housing to attach the semiconductor switching elements and to connect the semiconductor elements to each other or to the control circuit, which is difficult and complicated. There was a problem in that there was a large risk of interference with the rotor.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a drive circuit arrangement structure for a three-phase electric motor that is easy to assemble and can simplify wiring.

(Means for Solving the Problems) A drive circuit arrangement structure for a three-phase electric motor according to the present invention has a rotating shaft supported in a housing, a magnetic pole for field generation on one of the rotating shaft or the housing, and a three-phase electric motor drive circuit on the other. The phase winding is fixed, and a drive circuit connected to the three terminals of the three-phase winding is housed in the housing, and the drive circuit converts DC current into three-phase current to energize the three-phase winding. In the three-phase motor, the drive circuit includes semiconductor switching elements on the power supply side interposed between the terminals and the power source and semiconductor switching elements on the ground side interposed between the terminals and the ground for each of the three terminals of the three-phase winding. and a switching element, these six semiconductor switching elements are individually supported on six substrates arranged point-symmetrically with respect to the axis of the rotational shaft within the housing, and a drive signal is output to the semiconductor switching element. The gist is that a control circuit for controlling the circuit board is disposed at the center of each board.

(Function) According to the drive circuit arrangement structure for a three-phase electric motor according to the present invention, since each semiconductor switching element is provided concentrically around the control circuit, wiring between each element and between the element and the control circuit is reduced. It is possible to shorten the length and match the connection length. Further, since the semiconductor switching element is supported by the housing by the substrate, the substrate and the element can be subarranged, and the work of attaching the element is easy.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

Figures 1 to 6 show the drive circuit arrangement structure of a three-phase motor according to an embodiment of the present invention as an engine starting/power generation device assembled integrally with a charging generator, and Figure 1 shows the power from the engine. Overall sectional view shown with the transmission mechanism, 2nd
The figure is an enlarged sectional view of the main part, and Figure 3 is III-II of Figure 2.
4 is a sectional view taken along the IT-rV arrow in FIG. 2, FIG. 5(a) is a plan view of the main parts, and FIG. 5(b) is the -V arrow sectional view, FIG. 6 is a partial circuit diagram.

In Fig. 1, E is an engine, T is a planetary gear transmission, and S is a starter generator (hereinafter referred to as "starter generator") which is a combination of a three-phase electric motor (starter motor) and a three-phase alternator (charging generator). The crankshaft 11 of the engine E is provided with a flange joint 11a such as a spline at the end thereof, and is connected to a transmission T via the flange joint 11a.

The outer periphery of the flange joint 11a is supported by the crankcase of the engine E or the like with a ball bearing 12.

The transmission T includes a well-known sun gear 14, a planetary gear 15, and a housing 13 fixed to the outer wall of the engine E.
An electromagnetic clutch 18 houses a set of planetary gear mechanism P having a carrier 17 and a ring gear 16, and the ring gear 16 of this planetary gear mechanism P is provided in the housing 13.
When it is restrained, it is released and the gear shift is activated. The planetary gear mechanism P is
A sun gear 14 is integrally formed with the output shaft 19, and a carrier 17 is connected to the aforementioned flange joint 11a via a bushing 20 made of an elastic material such as rubber. A one-way clutch 21 that only allows power transmission to the output shaft 19 is interposed, and a plurality of locking holes (not shown) are formed in the ring gear 16 at regular intervals in the rotational direction. Although not clearly shown in the diagram,
The electromagnetic clutch IF3 has a locking pawl in the housing 13 that is swingably supported by a spring biased in a direction away from a locking hole in the ring gear 16, and the locking pawl is supported in response to the operation of the ignition key when the engine is started. Force it with a solenoid to lock it in the locking hole. The housing 1 is attached to the output shaft 19.
3. A crank pulley 22 is fixedly installed at the end projecting outward.
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. This transmission T locks the ring gear 16 with an electromagnetic clutch 18 when starting the engine, etc.
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 half-rests 27 and 28 is attached to the upper part of the engine E, and a shaft 23 is rotatably supported by the housing 26. Half holidays 27 and 28 are cylindrical walls 27a and Z8 respectively.
a and the end wall 27b.

28b, and has a substantially bottomed cylindrical shape, and
．． 28 has an opening connected thereto to define a mechanism chamber 29.

The half body 28 has a bearing hole 32a and a ventilation hole 3 in the end wall 28b.
3a, an open hole 34a is formed in the cylindrical wall 28a adjacent to the left side of the stator coil, which will be described later, and the half body 27
A bearing hole 32b and an air hole 33b are formed in the end wall 27b, and an open hole 34b is formed in the cylindrical wall 27a adjacent to the right side of the stator coil, which will be described later. Half-day 28 ventilation hole 3
3a penetrates the end wall 28b to communicate the cooling air passage described later with the mechanism chamber 29, and has bearing holes 32a, 3 at each half-opening 28°27.
A shaft 23 is rotatably supported on 2b via a ball bearing.

In the shaft 23, a permanent magnet 35 having a large number of poles in the rotational direction is fixed to the left end in the figure protruding from the end wall 28b of the half body 28, and a permanent magnet 35 having a large number of poles in the rotation direction is fixed to the right end in the figure protruding from the end wall 27b of the half body 27. The above-mentioned pulley 24 is fixedly installed, and a rotor 36 is fixedly installed in an intermediate portion within the mechanism chamber 29. The rotor 36 is
Two yoke half-holes 36a, 36b are fixed to the shaft 23, and a field coil 37 is held between these yoke half-holes 36a, 36b. Yoke half body 36a,
36b has opposing ends interlaced with each other in a comb shape, and a large number of magnetic poles are generated alternately in the circumferential direction on the outer periphery by excitation of the field coil 37. These yoke halves 36a,
36b has cooling fans 38a on both sides in the axial direction.
, 38b are attached. field coil 37
is connected to a slip ring 39 provided on the shaft 23 on the right side of the figure, and is connected to a voltage regulator 4o disposed on the right side of the mechanism chamber 29 via a brush 41 that contacts this slip ring 39. As is well known, the voltage regulator 40 is connected to a battery, energizes the field coil 37, and controls the field current flowing through the field coil 37.

A stator 42 is fixed to the inner wall of the mechanism chamber 29 of the housing 26 outside the rotor 36 .

The stator 42 includes a plurality of starting coils 44 arranged alternately in the circumferential direction on an annular yoke 43 fixed to the inner wall of the housing 26.
The starting coil 44 and the generating coil 44 (not shown in the figure and given the same number as the starting coil) are each wound in a distributed manner, and the starting coil 44 and the generating coil 44 are star-connected.

The starting coil 44 is connected to a drive circuit to be described later, and the power generation coil 44 is connected to a rectifier circuit 45 arranged on the right side of the mechanism chamber 29 in the figure. The rectifier circuit 45 is a known full-wave rectifier circuit made of diodes, etc., and is connected to a battery via a relay (not shown). This relay has a contactor that responds to the operation of the Ivnirasin key to the start position, etc., and disconnects the rectifier circuit 45 from the battery when the starting coil 44 is energized.

Further, a substantially cylindrical case 30 is fixed to the housing 26 and is formed by joining two members to the left side surface of the end wall 28b in the drawing. In the case 30, the left side in the figure on the side of the end wall 28b is entirely opened to define a circuit chamber 31 between the end wall 28b and the left side in the figure. It is formed. Inside the circuit chamber 31, a substantially cylindrical cylindrical member 46 is arranged coaxially with the case 30, and on the outside of this cylindrical member 46, six power modules 47□,
422, 47s, 474, 47s, and 47a (hereinafter represented by numbers without subscripts as necessary) are arranged.

The cylindrical member 46 has a large cylindrical portion 46a and a small cylindrical portion 46b separated by a partition wall 46c, and the right end opening of the small cylindrical portion 46b in the drawing is joined to the outer edge of the bearing 32a of the half body 28, and the shaft 2
3, and the opening at the left end in the figure of the large cylinder part 46a is opened with a mounting hole 30a. This cylindrical member 46 has a large cylindrical portion 46a! The IJ control circuit 48 is accommodated, and the small cylinder portion 48
A Hall element 4 is placed on the inner wall of b in the vicinity of the above-mentioned permanent magnet 35.
9 is fixedly installed. The Hall element 49 is 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 includes a controller including a microcomputer, a drive circuit for driving the electromagnetic clutch 18 described above, a delay circuit for delaying the energization of the starting coil 44 than the energization of the electromagnetic clutch 18, and the like. This control circuit 48 is connected to each power module 47, an ignition key switch, etc., and determines the phase of the current flowing to the starting coil 44 based on the detection signal output by the wheel element 49 when the engine is started, and converts the drive signal into a power source. Output to module 47.

The power module 47 is arranged concentrically within the circuit chamber 31 outside the cylindrical member 46, and has both axial ends fixed to substantially annular holding members (partition members) 50 and 51, respectively.

As shown in detail in FIG. 2, the holding member 50 on the right side of the figure is
Annular plates 50a and 50 made of insulating material such as Bakelite
b, and is fixed to the end wall 28b of the half body 28. Similarly, the holding member 51 on the left in the figure is formed by joining annular plates 51a and 51b made of an insulating material, and is fixed to the inner wall of the case 30 at the left end in the figure. A busper 52, which will be described later, is sandwiched between the annular plates 51a and 51b in the holding member 51, and three buspars 53, 54, and 55, which will be described later, are sandwiched between the annular plates 50a and 50b in the holding member 50. There is. The power module 47 is configured by providing eight PMOS-FET pair chips (hereinafter abbreviated as FET) 57 in a relatively thick, generally plate-shaped casing 56 . The casing 56 is made of a material with excellent electrical and thermal conductivity, such as aluminum, and houses 8 FETs 57.
It has a heat capacity corresponding to the amount of heat generated in a predetermined period of time.

This casing 56 extends orthogonally in the radial direction and in the axial direction, and both ends in the axial direction are fixed to the aforementioned holding member 50.51, and the casings 56 of the six power modules 47 are arranged in a hexagonal cylindrical shape as a whole. There is. In addition, 58a.

58b is a knock bottle for positioning. These casings 56 have a plurality of cooling fins 60 formed on their radially inner surfaces, and their inner surfaces define cooling air passages 59 extending in the axial direction between the casings 56 and the cylindrical member 46 described above. However, cooling fins 60 protrude into this cooling air passage 59. Cooling air passage 59
The left end in the figure is opened to the outside through the outside air hole 30b, and the right end in the figure is opened to the mechanism chamber 29 through the ventilation hole 33a.

As shown in FIG. 3, the cooling fins 60 protrude substantially in parallel toward the center in a stepped manner and extend in the axial direction.

Further, as shown in FIGS. 5(a) and 5(b), the casing 56 has the above-mentioned eight FETs 57 mounted on its radially outer surface.
A strip electrode 61 is fixed between these rows, and a strip electrode 62a having a built-in resistor on the outside of each row,
82b is arranged parallel to the 57 rows of FETs. FET
57 has a drain electrode formed on the joint surface with the casing 56, and this drain electrode is plated with nickel or the like and fixed to the casing 56 with solder or the like so as to be electrically and thermally conductive. These FETs 57 have their source electrodes connected to the strip electrode 61 and their gate electrodes connected to the strip electrodes 62a and 62b according to the columns, and are connected in parallel as a whole. The strip electrode 61 is fixed on the casing 56 via an insulating sheet 63, and similarly, the strip electrode 62a,
62b also has insulation sheets 64a and 64b on the casing 56.
It is fixed through. The radially outer portion of the casing 56 is closed with a lid 65 made of synthetic resin such as epoxy, and silicone gel 66 is sealed inside.

The six power modules 47 described above are connected to the starting coil 44 of the stator 42, as shown in FIG. 6, and constitute a drive circuit 67 that supplies three-phase current to the starting coil 44. As is clear from FIGS. 3, 4, and 6, the three power modules 471° 47□, 4γ, which are arranged adjacent to each other in the upper part of the drawings, connect the terminal of the starting coil 44 and the battery. Power modules 474, 475, 478, which are interposed therebetween and are also arranged adjacently below, are interposed between the starting coil 44 and ground.

Power modules 47r, 472, 47s are FET5
The drain of F.
The sources of the ET 57, that is, the left ends of the strip electrodes 61 are each held in a busper 53.5 approximately parallel to the holding member 50.
Power module 474,47s through 4.55,
47a, which is connected to the left end of the casing 56, and the gate of the FET 57, which is the strip electrode 62a,
62b is connected to the control circuit 48 by a harness or the like (not shown). In addition, three power modules 474, 4
75 and 476 are buspars 68 whose drains, that is, right end portions of the casing 56 pass through the holding member 51, respectively.
(only one is shown in the figure) is connected to the three terminals of the starting coil 44, and the source is connected to the left end of the half-stop 28 by a busper 69 (only one is clearly shown in the figure). The gate is connected to the control circuit 48. As clearly shown in FIG. 2, the bus spar 69 extends axially outside the power module 47 in the radial direction and has a bent portion 69a formed in the middle portion, and this bent portion 69a is connected to the cover body 69.
5 and holds the lid body 65.

Next, the operation of the embodiment will be explained.

The Stag S can be used as a starting motor when the field coil 37 is connected to the battery via the voltage regulator 40 and energized, and when the starting coil 44 of the stator 42 is energized with three-phase current at the time of starting the engine.
When the rectifier circuit 45 of the stator 42 is connected to the battery via a relay after the engine is started, the stator 42 functions as a charging generator that generates electricity using the power generation coil 44.

When starting the engine, the electromagnetic clutch 18 of the transmission T is energized by operating the ignition key to the start position, and when a predetermined period of time has elapsed after the start of energizing the electromagnetic clutch 18, the starting coil 44 is energized. Start. Therefore, in the transmission T, the locking pawl of the electromagnetic clutch 18 enters the locking hole of the ring gear 16, and the ring gear 1
After this, the Stag S is driven as a starting motor, and the output of the Stag S is decelerated by the transmission T and transmitted to the crankshaft 11 of the engine E, and the engine E is started by the Stag S. At the time of starting the engine, the drive circuit 6 energizes the starting coil 44 with three-phase current by the switching action of the FET 57, and the FET 57 generates heat during the energization period.
The heat generated by F5 is absorbed by the casing 56, so F
The temperature rise of ET57 is suppressed.

Next, when the engine E is started, in the transmission T, the electromagnetic clutch 18 is de-energized and the ring gear 16 is released, and in the stag S, the starting coil 44 is de-energized and the rectifier circuit 45 is de-energized. is connected to the battery. Therefore, the stag S is driven by the engine E via the transmission T to generate electricity, and the three-phase current generated in the power generation coil 44 is rectified by the rectifier circuit 45 and output. During power generation, the cooling fans 38a and 38b of the Stag S rotate together with the shaft 23, and as shown by the arrow in FIG.
0b, the cooling air flows through the cooling air passage 59 and the ventilation hole 33a to the open hole 34a, cooling the left side of each power module 47 and the coil 44 of the stator 42 in the figure, and the cooling fan 38b causes the cooling air to flow from the outside air hole 33b. Mechanism room 2
9 and into the open hole 34b to cool the rectifier circuit 45, the voltage regulator 40, and the right side of the coil 44 of the stator 42 in the figure. Therefore, the power module 47, the coil 44 of the stator 42, etc. can be effectively cooled. Furthermore, since the stator 42 and each power module 47 are isolated by the holding member 51 and the end wall 28b, there is no thermal influence on each other, and the power module 47 is
The temperature of the FET 57 can be prevented from rising, and the temperature of the FET 57 can be lowered when the engine is restarted immediately after being stopped.

On the other hand, in Stag S, each power module 47 is an FET.
57 is directly attached to the casing 56 in a conductive manner, and each power module 47 is arranged concentrically around the control circuit 48, so that the power modules 47 are connected to each other and between each power module 47 and the control circuit 48. The wiring can be simplified, and furthermore, it is possible to shorten the pathpers 52.53, 54.55 that connect the power modules 47 and match the resistance values.
4.55 are arranged in parallel, the risk of short circuits etc. can be extremely reduced.

Since each power module 4F can be assembled with FETs 57 and connected to each other in advance, it is easy to assemble the stag S.Furthermore, each power module 4F can be connected via the casing 56. Wiring is also easy.

In the above-described embodiment, the three-phase motor is exemplified as a starter motor assembled integrally with a charging generator, but it goes without saying that the present invention can be achieved with a single three-phase motor as well.

(Effects of the Invention) As explained above, according to the drive circuit arrangement structure for a three-phase motor according to the present invention, the drive circuit that outputs three-phase AC to the three-phase winding has a bridge shape with respect to the terminals of the three-phase winding. Since the semiconductor switching elements connected to each other are arranged concentrically around the control circuit using the substrate, the wiring length between each element and between the element and the control circuit can be shortened and matched. Also, the work of assembling the semiconductor switching element becomes easier.

[Brief explanation of drawings]

1 to 6 show an engine starting/charging device according to an embodiment of the present invention, in which FIG. 1 is an overall view, FIG. 2 is an enlarged sectional view of main parts, and FIG. III-III arrow sectional view, Figure 4 is the TV-mV arrow sectional view of Figure 2, Figure 5 (a) is a plan view of the main parts, Figure 5 (b) is Figure 5 (a) 6 is a partial circuit diagram. E... φ Engine S... Starting generator (three-phase electric motor) 36... Rotor 44... Starting coil 48.
...Control circuit 56...Casing (board) 57.
-FET (semiconductor switching element) 59...Cooling air path 60...Cooling fin 67...Drive circuit patent applicant Agent for Honda Motor Co., Ltd.
Patent Attorney Part 2 1) Part 1 Patent Attorney
Kuni Ohashi Opened the store Patent attorney Kuni
Mountain map map

Claims (5)

[Claims] (1) A rotating shaft is supported in the housing, and a magnetic pole for field generation is fixed to one of the rotating shaft or the housing, and a three-phase winding is fixed to the other, and the three terminals of the three-phase winding are In a three-phase motor that houses a connected drive circuit in a housing and converts direct current into three-phase current by the drive circuit to energize the three-phase winding, the drive circuit connects three terminals of the three-phase winding. Each of the six semiconductor switching elements is provided with a semiconductor switching element on the power supply side interposed between the terminal and the power supply and a semiconductor switching element on the ground side interposed between the terminal and the ground, and these six semiconductor switching elements are housed in the housing. The device is characterized in that it is individually supported by six substrates arranged point-symmetrically with respect to the axis axis, and a control circuit for outputting a drive signal to the semiconductor switching element is arranged at the center of each substrate. Drive circuit layout structure of three-phase motor. (2) The substrate is made of a conductive material and supported by the housing via a holding member made of a non-conductive material;
Driving a three-phase motor according to claim 1, characterized in that the semiconductor switching element is supported with one terminal electrically connected to the substrate, and the terminals of the semiconductor switching element are connected via the substrate. Circuit layout structure. (3) The three semiconductor switching elements on the power supply side are arranged adjacent to one side, and the three semiconductor switching elements on the ground side are arranged adjacent to the other side, and each terminal of the three-phase winding 3. The drive circuit arrangement structure for a three-phase motor according to claim 1, wherein the semiconductor switching element on the power supply side and the semiconductor switching element on the ground side are connected in parallel. (4) Cooling in which the substrate is made of a thermally conductive material, the semiconductor element is provided on the substrate in a heat-conductive manner, and the six substrates are arranged in a substantially hexagonal cylinder shape so that cooling air flows inside the center side. 4. The drive circuit arrangement structure for a three-phase motor according to claim 1, further comprising an air path defined therein. (5) The substrate supports the semiconductor switching element on an outer surface and has heat dissipation fins on an inner surface that protrude into the cooling air path. Phase motor drive circuit structure.