JP2003322082A - Inverter integrated type electric compressor for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inverter integrated type electric compressor for a vehicle capable of realizing excellent cooling of an inverter part, while suppressing complexity of a cooling structure of the inverter part, and improving vehicle mountability by a remarkable shortening of a shaft length as compared with a conventional one. <P>SOLUTION: Discrete transistors 6 of the inverter part 5 are individually fixed to an outer peripheral surface of a peripheral wall of a motor housing 4 cooled by low pressure coolant gas, and thereby the shaft length of the inverter integrated type electric compressor for the vehicle is remarkably shortened as compared with the conventional one without causing cooling insufficiency of the inverter part 5 to reduce the size of the whole of the device. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular inverter integrated electric compressor, and more particularly to improvement of a part of the inverter.

[0002]

2. Description of the Related Art A refrigeration cycle apparatus for a vehicle using an electric compressor that electrically drives a compressor section is known for maintaining air conditioning during idle stop. It is also known to cool the motor part of an electric compressor with a low-pressure refrigerant gas.

Further, there has been proposed a vehicle inverter integrated electric compressor in which an inverter section for driving an AC electric motor with a DC power source is mounted on the electric compressor. This conventional vehicle-inverter integrated electric compressor is
The motor unit and the compressor unit are integrated in the axial direction, and the inverter unit is fixed to the end surface of the motor unit opposite to the compressor unit. This inverter part
A three-phase inverter module that converts DC power into three-phase AC power and supplies power to the motor section, a smoothing capacitor that reduces DC current pulsation of this three-phase inverter module, and a controller for intermittently controlling the switching elements of the three-phase inverter module. It has a printed board on which an IC, a power supply IC, etc. are mounted, a heat sink fixed to the bottom surface of the three-phase inverter circuit IC, and the like.

[0004]

However, since the above-described conventional inverter-integrated electric compressor for a vehicle has a structure in which the motor section and the inverter section are arranged in the axial direction with respect to the compressor section, the conventional belt-driven electric compressor cannot be used. The axial length is significantly longer than the compressor, and it is not possible to simply replace the conventional belt-driven compressor, and the positioning of each device in the engine room, that is, the space distribution needs to be changed significantly, which increases the number of processes. There is a problem that the cost is often increased.

Further, the volume of the engine room tends to decrease year by year, and there is a particular demand for reduction in size and weight of this electric compressor with an integrated inverter.

Further, although the inverter part, especially the three-phase inverter module, requires good cooling, cooling the inverter part axially adjacent to the motor part has not been easy. That is, conventionally, the motor unit is blown out from a cooling fan fixed to the rotor, and thus is air-cooled by cooling air,
Alternatively, it may be cooled by the low-temperature low-pressure refrigerant gas that is introduced, but it is not easy to split the cooling air blown from the cooling fan or the low-pressure refrigerant gas in the axial direction or bend and introduce it into the inverter section. It was

The present invention has been made in view of the above problems, and realizes excellent cooling of the inverter section while suppressing the complication of the cooling structure of the inverter section, and also allows the vehicle to be mounted on the vehicle by significantly shortening the shaft length from the conventional one. It is an object of the present invention to provide an electric compressor integrated with a vehicle inverter that can be improved.

[0008]

According to a first aspect of the present invention, there is provided a vehicle-inverter-integrated electric compressor according to the present invention, which is a compressor part forming a part of a refrigeration cycle device, and the compressor part integrally connected to the compressor part. An inverter circuit for driving the motor, a housing for accommodating the compressor and the motor, and a predetermined number of power switching elements for converting the DC power into three-phase AC power to supply power to the motor unit. An electric compressor with a built-in inverter, wherein the motor part is cooled by a low-pressure refrigerant gas, each power switching element has a side surface from which an electrode terminal projects, and a motor part enclosing part of the housing. Separately composed of discrete transistors that have a bottom surface that directly adheres to the outer peripheral surface of the peripheral wall. It is characterized in that.

The discrete transistor mentioned above means a single power formed in a plate shape by resin-coating one IGBT or one MOST or a semiconductor chip provided with a pair of them and a flywheel diode. It means a transistor element. Further, the direct contact of the discrete transistor with the outer peripheral surface of the peripheral wall includes the case where the discrete transistor is adhered via a resin sheet or heat conductive grease.

According to the present invention, it is possible to realize a good cooling of the inverter part while suppressing the complication of the cooling structure of the inverter part, and to improve the vehicle mountability by greatly shortening the shaft length from the conventional inverter. A body type electric compressor can be realized. The features of the present invention will be provided in more detail below.

That is, according to the present invention, since the inverter section is fixed to the outer peripheral surface of the peripheral wall of the motor section, the axial length of the inverter-integrated electric compressor for a vehicle can be significantly reduced as compared with the conventional case.

Further, since the peripheral wall of the motor part is well cooled by the low pressure refrigerant gas flowing inside the motor part, it is sufficient to use the peripheral wall of the motor part as a heat sink of the inverter part as compared with the case where the peripheral wall is simply air-cooled. The temperature can be lowered to any level. Further, since the power switching element of the inverter unit is directly attached to the peripheral wall of the motor unit by utilizing this good cooling effect on the peripheral wall, the heat sink for the power switching device of the inverter unit, which has been essential in the past, can be omitted. Further, the heat transfer resistance between the power switching element and the peripheral wall as the low temperature heat source can be improved, and the heat radiation effect of the power switching element can be improved.
Furthermore, the heat capacity of the peripheral wall of the motor section is very large, and the short-term heat generation tolerance (short-time rating) of the power switching element of the inverter section can be greatly improved). Further, the radial height of the inverter section can be reduced by the amount that the heat sink, which was indispensable in the conventional power switching element, can be omitted, and the vehicle mountability of this inverter-integrated electric compressor for vehicles can be further improved. Can be improved.

Furthermore, according to the present invention, discrete transistors in which the power switching elements constituting each arm of the three-phase inverter circuit are separately packaged are individually and closely attached to the outer peripheral surface of the peripheral wall. As a result, the structure of the peripheral wall outer peripheral surface portion (also referred to as a pedestal portion) that is in contact with the inverter unit is thermally and thermally improved as compared with the case where the conventional three-phase inverter module having the built-in three-phase inverter circuit is closely attached to the peripheral wall outer peripheral surface. It can be improved in strength. In other words, the conventional three-phase inverter module requires a larger peripheral wall contact area than the discrete transistor of the present invention, but the peripheral wall outer peripheral surface is essentially a cylindrical surface, so the peripheral wall on which the three-phase inverter module is mounted is mounted. It is necessary to increase the height of the pedestal portion on the outer peripheral surface, that is, the thickness of the peripheral wall, which increases the heat transfer resistance from the inner peripheral surface of the peripheral wall. On the other hand, in the present invention, the pedestal on which the individual discrete transistors are mounted can be made small, so that the height of the pedestal, that is, the peripheral wall thickness can be reduced, and the heat transfer resistance can be reduced. Therefore, the cooling performance of the power switching element of the inverter unit is improved.
In addition, since this operation effect requires detailed explanation,
This will be specifically described by way of examples.

In a preferred aspect 1, the outer peripheral surface of the peripheral wall of the housing has a pedestal portion having a flat pedestal surface to which a flat bottom surface of the discrete transistor is closely fixed, and the discrete transistor is the pedestal. In a region of the surface that abuts the discrete transistor and in a portion where the peripheral wall of the housing is thick, it is unevenly distributed in the circumferential direction and is fastened to a screw hole formed in the peripheral wall at a right angle to the pedestal surface. There is.

That is, in this aspect, the discrete transistors are fastened to the peripheral wall of the housing by being unevenly distributed on one side in the circumferential direction having a large wall thickness in the portion of the pedestal portion on which the discrete transistors are mounted. Upsizing,
It is possible to fasten the discrete transistor to the pedestal while preventing an increase in weight and heat transfer resistance.

In a preferred aspect 2, each electrode terminal of the discrete transistor protrudes in the circumferential direction in a direction in which the peripheral wall of the housing is thin on the pedestal surface. As a result, the floating height of the electrode terminal from the outer peripheral surface of the peripheral wall can be reduced, the radial bulging of the inverter section can be reduced, and the size of the inverter-integrated electric compressor can be reduced. In addition, it becomes easy to make the bonding positions of the electrode terminals of the discrete transistors flush with each other.

In a preferred aspect 3, the discrete transistors are closely fixed to the pedestal surface forming the same plane. As a result, the bonding positions of the electrode terminals of the discrete transistors can be easily made flush with each other, the workability of the wiring connection work can be improved, and automation can be facilitated.

In a preferred aspect 4, the discrete transistors of different phases are arranged adjacent to each other in the axial direction, and the pair of discrete transistors of the same phase are
A wiring in which the electrode terminals of the pair of discrete transistors of the same phase project between the pair of discrete transistors of the same phase, which are arranged adjacent to each other in the circumferential direction with the electrode terminals facing each other in the circumferential direction. Has an area.

As a result, the wiring portions forming the three-phase inverter circuit by connecting the discrete transistors can be formed with high density, and the wiring length can be shortened.

In a preferred aspect 5, the peripheral wall of the housing, which faces the wiring region in a radial direction, projects outward in a direction perpendicular to the pedestal surface with respect to the pedestal portion. As a result, the thickness of the peripheral wall adjacent to this wiring area can be increased without disturbing the arrangement of the discrete transistors and increasing the height of the inverter section, thereby improving the mechanical strength of the housing. You can In this aspect, in order to form a flat pedestal surface having an area required for mounting discrete transistors while suppressing an increase in the thickness of the pedestal portion, a part of the outer peripheral surface of the peripheral wall is thinned, and this thinning is performed. When the wiring region is arranged adjacent to the portion, the reduction in mechanical strength of the thinned portion can be well compensated, which is particularly preferable.

In a preferred aspect 6, there is provided a resin member which is partitioned and formed by an outer frame portion which is tightly fixed to the outer peripheral surface of the peripheral wall of the housing and which is filled in a closed space for accommodating the discrete transistors.

To further explain, when the three-phase inverter circuit is composed of a large number of discrete transistors, it is naturally necessary to wire the terminals of the discrete transistors. In the present invention, the discrete transistor is directly attached to the outer peripheral surface of the metal housing of the electric compressor, and the electrode terminal is projected from the side surface of the discrete transistor along the outer peripheral surface of the housing. Inevitably, the electrode terminals and the wiring (for example, a bus bar) connected thereto and the outer peripheral surface of the peripheral wall of the housing come close to each other, which causes a risk of creeping discharge.

Therefore, in this aspect, the outer frame portion surrounding each discrete transistor is fixed to the outer peripheral surface of the peripheral wall of the housing, and preferably, the top surface of the outer frame portion (if it is the upper surface, it is not the outermost radial direction). The outer frame portion and the outer peripheral surface of the peripheral wall of the housing form a space surrounding each discrete transistor and wiring, and a resin is sealed in this space. The resin needs to be in a liquid or gel state at the time of injection, but it may be a resin that is cured naturally or by heating after the injection.

With this configuration, it is possible to easily prevent the creeping discharge between each of the electrode terminals and the wirings described above and the outer peripheral surface of the peripheral wall of the housing, and at the same time, the printed circuit board, the bus bar wiring, and various electric wires are provided in this space. By accommodating the connection points, the electrical insulation and vibration resistance of these can be significantly improved at the same time. The outer frame portion is preferably made of resin, but may be made of metal, and may be formed integrally with the peripheral wall of the housing, and can be easily fastened to the outer peripheral surface of the peripheral wall of the housing with screws or the like.

Further, by filling the space in the outer frame portion in which the printed circuit board, wiring and terminals are accommodated with an electrically insulating substance, the vibration energy of vibration of the electric compressor applied to the printed circuit board, wiring and terminals is attenuated. Therefore, it is useful for improving the reliability, especially the reliability of the connecting portion.

In a preferred aspect 7, an electrically insulating resin sheet is provided on the outer peripheral surface of the peripheral wall facing the wiring region.

To further explain, when the three-phase inverter circuit is composed of a large number of discrete transistors, it is naturally necessary to wire the terminals of the discrete transistors. In the present invention, the discrete transistor is directly attached to the outer peripheral surface of the metal housing of the electric compressor, and the electrode terminal is projected from the side surface of the discrete transistor along the outer peripheral surface of the housing. Inevitably, the electrode terminals and the wiring (for example, a bus bar) connected thereto and the outer peripheral surface of the peripheral wall of the housing come close to each other, which causes a risk of creeping discharge.

Therefore, in this embodiment, an insulating sheet is attached to the wiring region where the electrode terminals of the discrete transistors and the bus bars connected to them are close to each other. The insulating sheet needs to be embedded at least between the discrete transistor and the outer peripheral surface of the peripheral wall of the housing. As a result, the gap width between the electrode terminal of each discrete transistor and the bus bar connected to the discrete transistor and the outer peripheral surface of the peripheral wall of the housing can be shortened, and the height of the inverter section can be reduced.

In a preferred aspect 8, a smoothing capacitor is provided on the side opposite to the wiring region with the power switching element interposed therebetween.

That is, in this aspect, the smoothing capacitors are arranged adjacent to the discrete transistor group in the circumferential direction. At this time, the terminal of the smoothing capacitor is protruded in a direction perpendicular to the pedestal surface on which the discrete transistor is mounted and away from the outer peripheral surface of the peripheral wall of the housing in terms of wiring work. At this time, since the smoothing capacitors adjacent to the discrete transistor group or adjacent to the pedestal surface in the circumferential direction can be deeply arranged, it is possible to prevent the inverter section from widely spreading laterally, and The width can be reduced. Moreover, since the DC power supply terminal is arranged in the same direction as the smoothing capacitor, the smoothing capacitor can be arranged between the three-phase inverter circuit and the DC power supply terminal, and the high frequency of the switching current of the three-phase inverter circuit can be set. The components can be absorbed by the smoothing capacitor before reaching the DC power supply terminal, and the total length of the DC power supply wiring connecting them can be shortened to reduce the wiring inductance and the switching surge noise voltage. be able to.

Further, although the DC power supply terminal portion is connected to the external cable, the connection space with the external cable can be easily and sufficiently secured for the same reason.

[0032] In a preferred aspect, it has an AC output terminal portion arranged on the opposite side of the smoothing capacitor with the power switching element interposed therebetween.

With this arrangement, a sufficient space in the AC output terminal can be secured in the depth direction, and since it is arranged on the side opposite to the smoothing capacitor and the DC power supply terminal in the circumferential direction, the width in the axial direction is also increased. You can secure enough.

In the above embodiment, the inverter section is arranged on the outer peripheral surface of the motor section. As a result, it is possible to reduce the thermal adverse effect from the compression chamber of the compressor part, reduce the influence of vibration of the compressor part that acts on the inverter part, and also the length of the connection line between the inverter part and the motor part. It can be shortened. Furthermore, in order to reduce the above-mentioned thermal adverse effect, it is preferable that the lead-out terminal of the stator coil of the motor section is pulled out to the side opposite to the compressor section in the axial direction, and then pulled out from the peripheral wall of the housing.

In order to improve the cooling performance of the inverter section, a passage through which a low-temperature low-pressure refrigerant gas flows may be provided in the peripheral wall of the housing directly below the inverter section. This passage preferably diverts the low-pressure refrigerant gas sent to the motor section,
Alternatively, the low-pressure refrigerant gas returned from the evaporator may be introduced into the motor section through the passage directly below the inverter section. As a result, the inverter section can be cooled by the low-pressure refrigerant gas whose temperature is lower than that of the motor section.

[0036]

BEST MODE FOR CARRYING OUT THE INVENTION A preferred embodiment of an electric compressor with an integrated inverter in a vehicle refrigeration cycle apparatus to which the present invention is applied will be described with reference to the drawings. In each figure,
Members and lines are appropriately omitted.

FIG. 1 is an exploded perspective view of this inverter-integrated electric compressor.

FIG. 2 is a radial cross-sectional view of the inverter circuit portion of the inverter-integrated electric compressor shown in FIG. 1, but only the housing and the inverter circuit portion are shown. In FIG. 2, since the refrigerant circuit itself other than the inverter-integrated electric compressor is well known, illustration and description thereof will be omitted.

FIG. 3 shows a pedestal surface 41 of the motor housing 4.
FIG. 6 is an exploded perspective view showing a state in which the power MOS transistor module 6 is mounted on the power supply.

FIG. 4 shows a pedestal surface 41 of the motor housing 4.
FIG. 7 is a plan view showing a state after completion of mounting the power MOS transistor module 6 on FIG.

FIG. 5 is a perspective view showing a part of the bus bar in the bus bar built-in plate.

FIG. 6 is a plan view of the apparatus showing a state in which the printed board 9 is mounted.

(Overall structure) 1 is a compressor section which is a part of a refrigeration cycle apparatus for vehicle air conditioning, 2 is a motor section which drives the compressor section 1, and 3 is a compressor section 1
A compressor housing (a housing in the present invention) forming an outer shell of the motor, 4 is a motor housing (a housing in the present invention) forming an outer shell of the motor portion 2, and 5 is an inverter for driving and controlling the motor portion 2 including a three-phase synchronous motor. Section (inverter circuit section in the present invention).

Both housings 3 and 4 are adjacent to each other in the axial direction of a rotary shaft (not shown) and coaxially connected by a through bolt (not shown) so that the rotary shaft of the motor unit 2 drives the rotary shaft of the compressor unit 1. And, as a whole, constitutes the electric compressor referred to in the present invention. The outer peripheral surface of the motor housing 4 has a pedestal portion 40 that projects upward in FIGS. 1 and 2, and the top surface of the pedestal portion 40 has a pedestal surface 41 that is flat in the horizontal direction in FIGS. Have

The motor unit 2 is an evaporator (not shown).
It is cooled by the low-pressure refrigerant gas before being discharged or introduced from. In FIG. 6, 21 is a low pressure refrigerant gas inflow hole provided in the motor housing 4, and 22 is a low pressure refrigerant gas outflow hole provided in the motor housing 4. The motor housing 4 is well cooled by the low-pressure refrigerant gas flowing inside the motor housing 4.

The inverter section 5 includes six power MOS transistor modules (power switching elements) 6 which constitute an upper arm side switching element and a lower arm side switching element of each phase of the three-phase inverter circuit, a smoothing capacitor 7, and It has a bus bar built-in plate / outer frame part (bus bar built-in plate and outer frame part in the present invention) 8, a printed circuit board 9, and a lid plate 10, and has three phases of DC power supplied from a battery (not shown). The AC power is converted and supplied to a stator coil (not shown) of the motor unit 2.
Therefore, the connection point between the power MOS transistor module 6 forming the upper arm side switching element of each phase and the power MOS transistor module 6 forming the lower arm side switching element is connected to the lead wire of each phase of the motor unit 2. The remaining main electrode terminals of the three power MOS transistor modules 6 forming the arm side switching element are connected to the power supply terminal described later, and the three power MOS transistor modules 6 forming the lower arm side switching element.
The remaining main electrode terminal is connected to the ground terminal described later.

Power MOS transistor module 6
Is a resin-molded thick plate and, as shown in FIG. 3, has a drain electrode terminal 61 and a source electrode terminal 62 as main electrode terminals protruding from one side surface, and a gate electrode terminal 63 as a control electrode terminal. Have Further, a through hole 64 for fastening the power MOS transistor module 6 to the motor housing 4 is formed so as to be unevenly distributed on the side surface side of the power MOS transistor module 6 opposite to the side surface on the electrode terminal protruding side.

As is well known, the smoothing capacitor 7 is connected between the power supply terminal and the ground terminal of the three-phase inverter circuit and absorbs the high frequency component of the switching current of the three-phase inverter circuit.

The bus bar built-in plate / outer frame portion 8 has a large number of bus bars forming wiring of the three-phase inverter circuit and is fastened to the outer peripheral surface of the peripheral wall of the motor connector portion 14. Each bus bar is integrated by resin insert molding. The bus bar built-in plate / outer frame portion 8 is for each power MO.
Connection between S-transistor modules 6, each power MOS
Connection between the transistor module 6 and the printed circuit board 9,
Connection between each power MOS transistor module 6 and the smoothing capacitor 7, each power MOS transistor module 6, the DC power supply terminal portion and the ground terminal, each power MO
It is used to connect the S-transistor module 6 and the AC terminal.

A control circuit is mounted on the printed circuit board 9. This control circuit has a function of intermittently controlling each power MOS transistor module 6 based on a command from the outside and a function of transmitting the driving state of the motor unit 2 to the outside, and various circuit elements such as a microcomputer IC. Are connected by printed wiring.

Since the circuit configuration of the inverter unit 5 of this type and its operation are well known, the description thereof will be omitted, and the characteristic configuration of the inverter unit 5 forming the characteristic portion of this embodiment will be described below. (Arrangement of Inverter Section 5) Each power MOS transistor module 6 has a screw 12 through a resin insulation sheet 11.
Is fixed to the pedestal surface 41 of the pedestal portion 40.

Each power MOS transistor module 6
As shown in FIGS. 3 and 4, the power MOS transistor modules 6 are arranged adjacent to each other in three columns in the axial direction and two rows in the circumferential direction, and the electrode terminal projecting side surfaces of each power MOS transistor module 6 face each other.

The power MOS transistor module 6 on one side in the circumferential direction constitutes an upper arm side switching element,
Power MOS transistor module 6 on the other side in the circumferential direction
Constitutes a lower arm side switching element. The power MOS transistor module 6 on the one side in the axial direction constitutes a U-phase switching element,
The transistor module 6 constitutes a V-phase switching element, and the power MOS transistor module 6 on the other side in the axial direction constitutes a W-phase switching element. A wiring region W having a predetermined width in the circumferential direction is formed between the three power MOS transistor modules 6 forming the upper arm side switching element and the three power MOS transistor modules 6 forming the lower arm side switching element. Of the two power MOS transistor modules 6 of the same phase, the source terminal 62 of the power MOS transistor module 6 on the upper arm side and the drain terminal 61 of the power MOS transistor module 6 on the lower arm side are set at the same axial position, As a result, the length of the bus bar that connects these terminals to the AC output terminal portion can be shortened.

As shown in FIG. 2, the pedestal surface 41 of the pedestal portion 40 formed on the outer peripheral surface of the peripheral wall of the motor housing 4 is radially outside in the wiring area W as compared with the area in contact with the power MOS transistor module 6. It has a protrusion 42 that protrudes by a predetermined thickness. As a result, the thickness of the wiring region W, which has the smallest thickness as a whole, can be increased, and the strength and rigidity of the motor housing 4 can be improved. This thickening of the peripheral wall means that each electrode terminal of the power MOS transistor module 6 is projected from the side surface of the power MOS transistor module 6 at a position higher than the bottom surface of the power MOS transistor module 6 by a predetermined height, and resin insulation is performed. Even if the distance between the outer peripheral surface of the motor housing 4 and each electrode terminal of the power MOS transistor module 6 is shortened by laying the seat 11 on the entire pedestal portion 40 including the portion facing the wiring region W, the seat 11 and the seat terminal 11 can be shortened. It utilizes the fact that creeping discharge can be prevented satisfactorily.

The screw 12 is inserted into the through hole 64 formed unevenly on the side surface of the power MOS transistor module 6 on the side opposite to the electrode terminal projecting side, and the screw 12 is fastened to the pedestal portion 40 to power MOS. The transistor module 6 is fixed. Since the through-holes 64 are eccentrically provided on one side in the circumferential direction so as to be separated from the wiring region W, the female screw holes for fastening the screws 11 can be formed without increasing the thickness of the pedestal portion 40 in the vertical direction. It can be formed on the portion 40.

The smoothing capacitor 7 is located on one side in the circumferential direction of the power MOS transistor module 6 and is housed in a capacitor housing hole 13 which is formed in the outer peripheral surface of the motor housing 4 at a right angle to the pedestal surface 41. 7
The pair of terminals of the above are projected from the upper surface of the smoothing capacitor 7. At the position of the capacitor housing hole 13, the vertical thickness of the motor housing 4 can be ensured to be thicker, so that the depth of the capacitor housing hole can be ensured sufficiently. The vertical height of the pair of terminals can be suppressed, and the protruding height of the inverter unit 5 can be reduced.

A motor connector portion 14 is formed on the other side in the circumferential direction of the power MOS transistor module 6, that is, on the side opposite to the smoothing capacitor 7.

As shown in FIG. 2, the motor connector portion 14 is a cup-shaped connector housing 15 located on the other side in the circumferential direction of the pedestal portion 40 and protruding from the outer peripheral surface of the peripheral wall of the motor housing 4, and is opened upward. A lid 16 made of resin for closing the opening of the connector housing 15, and a lid 16
A resin-made connector cover 17 arranged on the upper side of
It has an AC terminal 18 fixed to the lid 16. Although not shown, the three AC terminals (only one is shown) 18 project into the lead wire accommodation space S in the connector housing 15 sealed by the lid 16, and the lead wire accommodation space S Are individually connected to three lead wires extending from the stator coil of the motor unit 2. These lead lines are drawn from the inside of the motor housing 4 to the lead wire accommodation space S through the lead wire holes 19 provided in the peripheral wall of the motor housing 4.

The bus bar built-in plate / outer frame portion 8 comprises a bus bar built-in plate 81 and an outer frame 82. The above-mentioned connector cover 17 is resin-molded integrally with the bus bar built-in plate / outer frame portion 8 as a part of the outer frame portion 82.

As shown in FIGS. 1, 4, and 6, the outer frame portion 82 has a rectangular frame shape, is mainly seated on the pedestal surface 41, and is fastened to the pedestal portion 40. Connector cover 1
7 is integrally formed in a U shape on one outer surface of the outer frame portion 82 and surrounds the AC terminal 18. On the side surface of the outer frame portion 82, a pair of power connector 20 and communication connector 21 are provided so as to be located on the side opposite to the connector cover 17.

The bus bar built-in plate 81 includes an outer frame portion 82.
It is located above the power MOS transistor module 6 from the inner side surface thereof, and extends horizontally, that is, parallel to the pedestal surface 41. The busbar built-in plate 81 is a power MOS.
A large number of bus bars that connect the transistor module 6, the printed board 9, and the AC terminals 17 are arranged in two layers in the vertical direction, and each bus bar is integrally formed by a resin molding plate portion 83. From the bus bar built-in plate 81 to the ground (-) terminal 22 and the power (+) terminal 23 are the power connector 2
It is connected to a DC power supply cable (not shown) that projects into 0 and fits into the power supply connector 20. Ground (-) terminal 2
Reference numeral 2 denotes one end of a grounding bus bar in the bus bar built-in plate 81. The grounding bus bar is a source electrode terminal 62 of the power MOS transistor module 6 and a negative electrode terminal of the smoothing capacitor 7 which form each lower arm side switching element. And the grounding wiring pattern of the printed circuit board 9. The power supply (+) terminal 23 is connected to the drain electrode terminal 61 of the power MOS transistor module 6 forming each upper arm side switching element, the positive terminal of the smoothing capacitor 7, and the power supply wiring pattern of the printed board 9.

Communication terminals (not shown) project from the bus bar built-in plate 81 into the communication connector 21 and are connected to a communication cable (not shown) fitted into the communication connector 21. Bus bar built-in plate 81 to 3-phase AC terminal 2
4 to 26 project in the horizontal direction, and the AC terminals 24 to 26 are the AC terminals 1 on the motor section 2 side in the connector cover 17.
It adheres to 8. The terminals horizontally protruding from the bus bar built-in plate 81 into the outer frame portion 82 are bent downward and joined to the respective electrode terminals of the power MOS transistor module 6 in the wiring region W. X indicates this joint.
Similarly, the terminal projecting upward from the bus bar built-in plate 81 into the outer frame portion 82 is inserted into the through hole 91 of the printed board 9 and soldered at this through hole.

The outer peripheral edge of the printed circuit board 9 is placed on a step surface 84 provided inside the outer frame portion 82 and fixed by screws. The printed board 9 is arranged in parallel to the bus bar built-in plate 81 above the bus bar built-in plate 81 with a predetermined distance from the bus bar built-in plate 81. Resin molding plate portion 8 of bus bar built-in plate 81
3 has a central support column 830 that abuts the lower surface of the printed circuit board 9 at the central portion in the horizontal direction, and regulates the vibration of the printed circuit board 9. A circuit component C such as an IC mounted on the printed board 9 is mounted on the lower surface of the printed board 9. By doing so, the terminals of the bus bar protruding from the bus bar built-in plate 81 and penetrating through the through holes 91 of the printed circuit board 9 can be simultaneously formed on the upper surface of the printed circuit board 9 simultaneously with each circuit component of the printed circuit board 9 by, for example, a jet solder method. Can be soldered.

The lid plate 10 is fastened to the top surface 85 of the outer frame portion 82, and gel is filled inside the outer frame portion 82 to improve moisture resistance and vibration resistance of the inside. Further, resin is molded inside the frame-shaped connector housing 17, and the AC terminals 24 to 2 from the bus bar built-in plate 81 are molded.
6 and the AC terminal 18 from the motor unit 2 are insulated and protected.

In this embodiment, the gel and the mold resin are heated at the same time, but they may be heated separately, and a mold resin may be used instead of the gel.

(Assembling Order) Next, the assembling order of the inverter section 5 will be described below.

First, the bus bar built-in plate / outer frame portion 8 and the printed board 9 are integrated by soldering and screws,
The power MOS transistor module 6 is fastened to the pedestal portion 40 of the motor housing 4.

Next, the integrated body of the plate / outer frame portion 8 having a built-in bus bar and the printed circuit board 9 is fixed to the motor housing 4, and the tool is inserted from the portion opening upward, and the power MOS transistor module 6 is inserted. Of the smoothing capacitor 7 and the terminal of the plate / outer frame portion 8 with a built-in bus bar are joined together to connect the AC terminals 24 to 26 of the plate / outer frame portion 8 with a built-in bus bar and the AC terminal 18 on the side of the motor unit 2. Contact. Next, the outer frame portion 82 is filled with gel, liquid resin is injected into the connector housing 17, the lid plate 10 is fixed, and heat treatment is performed to cure the liquid resin. (Effects of Embodiments) Various operational effects of the electric compressor with a built-in inverter for a vehicle according to this embodiment described above will be listed below. (1) The power MOS transistor modules 6 of the inverter section are individually arranged in a matrix and directly attached to the outer peripheral surface of the peripheral wall of the housing cooled by the low-pressure refrigerant gas. As a result, it is possible to realize good cooling of the inverter unit while preventing the inverter unit cooling structure from becoming complicated, and to improve vehicle mountability by shortening the shaft length. Furthermore, since the peripheral wall of the motor housing 4 can be used as a heat sink for the power MOS transistor module 6, the inverter unit 5 can be made smaller and lighter and the heat radiation resistance can be reduced. (2) Power is applied to a thicker portion of the pedestal portion 40 whose thickness continuously changes in the circumferential direction because it is defined by a flat pedestal surface extending in the tangential direction and an arcuate inner peripheral surface. MO
Since the screw hole for fastening the S-transistor module 6 is provided, it is possible to fasten the discrete transistor to the pedestal portion while preventing the pedestal portion from increasing in size and weight and heat transfer resistance. (3) A pedestal whose thickness continuously changes in the circumferential direction because each electrode terminal of the power MOS transistor module 6 is defined by a flat pedestal surface extending in a tangential direction and an arcuate inner peripheral surface. Since the part 40 is projected in the direction in which the wall thickness is reduced, the pedestal part 40 can be downsized. In particular, when the two power MOS transistor modules 6 are arranged to face each other in the circumferential direction, the thickness (bulging in the radial direction) of the pedestal portion 40 on which these two power MOS transistor modules 6 are mounted is reduced to reduce the inverter size. It is possible to reduce the size of the body type electric compressor. In addition, it becomes easy to make the bonding positions of the electrode terminals of the discrete transistors flush with each other. (4) Since each power MOS transistor module 6 is fixed to the pedestal surface 41 forming the same plane, each power MOS transistor module 6 is fixed.
It is easy to make the bonding positions of the electrode terminals of the transistor module 6 flush with each other, the workability of wiring connection work can be improved, and automation can be facilitated. (5) Power MOS transistor modules 6 of different phases are arranged adjacent to each other in the axial direction, and a pair of power M of the same phase is provided.
The OS transistor modules 6 are arranged adjacent to each other in the circumferential direction with their electrode terminals facing each other in the circumferential direction, and a pair of power MOS transistor modules 6 of the same phase facing each other.
Since the electrode terminal projects between the wiring regions and the wiring region W is joined to the bus bar, the two power MOS transistor modules 6 facing each other in the circumferential direction can share the wiring region W between the two power MOS transistor modules 6 and the inverter portion. The required area of 5 can be reduced, and the wiring length of the bus bar can also be reduced. (6) The pedestal surface 41, which is the outer peripheral surface of the peripheral wall of the motor housing 4 immediately below the wiring area W (that is, radially adjacent to the wiring area W), has a diameter larger than that of the pedestal surface 41 that contacts the bottom surface of the power MOS transistor module 6. Since it is projected outward in the direction, it is possible to improve the strength of this peripheral wall portion, which is the thinnest of the peripheral walls of the motor housing 4 while suppressing the height of the inverter portion 5, and has a weaker strength. (7) A space defined by the motor housing 4, the outer peripheral surface of the peripheral wall, the outer frame portion 82, and the cover plate portion 15 to accommodate the power MOS transistor module 6, the bus bar built-in plate 81, the printed board 9, and the smoothing capacitor 7, Since the gel-like resin member is filled, it is possible to improve the moisture-proof property and increase the density of the wiring, and at the same time, it is possible to satisfactorily reduce the vibrations of the printed circuit board 9 and the bus bar built-in plate 81 and prevent the harmful effects thereof. (8) Since the resin insulation sheet 11 is laid on the outer peripheral surface of the peripheral wall of the motor housing 4 facing the wiring region W, each power M
The electrode terminals and the bus bar of the OS transistor module 6 can be arranged close to the outer peripheral surface of the peripheral wall of the motor housing 4, and the height of the inverter unit 5 can be suppressed. (9) The pedestal surface 4 is located on one side in the circumferential direction in the direction away from the wiring region W of the power MOS transistor module 6.
The smoothing capacitor 7 is housed in a capacitor housing hole that is recessed at a right angle to 1, and the terminals of the smoothing capacitor 7 are provided on the upper surface of the smoothing capacitor 7. At this portion, the thickness of the pedestal portion 40, which is measured at right angles to the pedestal surface 41, is very large, so that the capacitor accommodating hole can be sufficiently secured. As a result, the smoothing capacitor 7 can be satisfactorily cooled by the motor housing 4, and the height of the terminals of the smoothing capacitor 7 can be made close to the height of the bus bar built-in plate 81, so that the wiring length to the smoothing capacitor 7 can be shortened. In addition, the height of the inverter unit 5 can be suppressed. In other words, the smoothing capacitor 7 has power M
It is arranged adjacent to the OS transistor module group in the circumferential direction, and the terminals of the smoothing capacitor 7 project in a direction perpendicular to the base surface 41 and away from the outer peripheral surface of the peripheral wall of the motor housing 4. As a result, the smoothing capacitor 7 can be arranged at a right angle to the pedestal surface 41 and deep toward the motor housing 4, and the inverter section can be reduced in size. In addition, the DC power supply terminal also has a smoothing capacitor 7
The smoothing capacitor 7 can be arranged between the three-phase inverter circuit and the DC power supply terminal by arranging the same in the same direction, and the total length of the DC power supply wiring connecting them can be shortened to reduce the wiring inductance. The switching surge noise voltage can be reduced thereby. (10) Further, the power MOS transistor module 6
Power MOS on the opposite side of the smoothing capacitor 7 across
The motor unit 2 is provided on the other side in the circumferential direction of the transistor module 6.
Since the AC output terminal is provided, the AC output terminal can be provided in a sufficient area without being disturbed by the smoothing capacitor 7, and the AC output terminal can be provided for the same reason as in the case of the smoothing capacitor 7. It is possible to secure a sufficient depth of the motor connector portion 13 surrounding the. (11) Since the busbar built-in plate 81 formed by resin molding a large number of busbars is provided above the power MOS transistor module 6, that is, outside in the radial direction, the busbars can be mounted without considering deformation of the busbars due to vibration or collision of the electric compressor. They can be arranged at high density, and the inverter unit 5 can be downsized. Further, the alignment work of each bus bar is only required once, which simplifies the wiring work. Further, electromagnetic switching noise radiated to the outside by the power MOS transistor module 6 can be shielded by the DC bus bar extending above the power MOS transistor module 6. (12) Since the printed circuit board 9 is provided further in the radial direction outside the bus bar built-in plate 81 in parallel with the bus bar built-in plate 81, the wiring amount of the bus bar built-in plate 81 can be reduced and the size and weight thereof can be reduced. Since the board (small current wiring), the bus bar built-in plate (large current wiring), and the power MOS transistor module 6 have a three-story structure, the wiring distance can be shortened and the inverter section can be miniaturized. In this three-story structure, vertical wiring between the printed circuit board 9 and the power MOS transistor module 6 is required, which is formed by bending one end of the bus bar of the bus bar built-in plate 81 upward.
This can be realized by bending the other side downward, and it is possible to prevent the wiring structure from becoming complicated. Since the outer frame portion 82 of the plate / outer frame portion 8 having a built-in bus bar constitutes a power supply connector portion surrounding the DC power supply terminal portion, the number of parts can be reduced. (13) Busbar built-in plate 81, power MOS transistor module 6, outer frame portion 8 surrounding the printed circuit board 9
2 is provided by resin molding integrally with the bus bar built-in plate 81, and the outer edge of the bus bar built-in plate 81 is formed by the outer frame portion 82.
The outer frame portion 82 is fixed to the inner surface of the printed circuit board 9.
And holding the bus bar built-in plate 81 hollow, and power M
Mechanical protection of the OS transistor module 6 and the printed circuit board 9 can be realized. Further, since the bus bar built-in plate 81 is integrated with the outer frame portion 82,
It is possible to improve the vibration resistance and mechanical resistance of the bus bar built-in plate 81 against the vibration of the electric compressor and the acceleration force at the time of a vehicle collision. (14) Since the printed circuit board 9 is fastened to the stepped surface of the outer frame portion 82 and the lid plate is fastened to the top surface of the outer frame portion 82, the mounting of the printed circuit board 9 is very easy and the printed circuit board 9 It is possible to remarkably improve the alignment accuracy of the terminal hole 9 and the terminal of the bus bar protruding from the bus bar built-in plate 81. (15) Since the resin-molded plate portion is integrally resin-molded and has the central support column portion that is in contact with the central portion of the printed circuit board 9, the vibration resistance of the printed circuit board can be further improved. (16) Among the bus bars of the bus bar built-in plate 81, the grounding bus bar forming the low-order DC line of the three-phase inverter circuit is fixed to the outer peripheral surface of the peripheral wall of the motor housing 4, so that cooling of the power MOS transistor module 6 and three-phase Shorter ground wiring length of inverter circuit, power MO
It is possible to improve the electromagnetic shield effect for the S transistor module 6. (17) Among the bus bars of the bus bar built-in plate 81, the power source bus bar forming the high-order DC line of the three-phase inverter circuit is in close contact with the outer peripheral surface of the peripheral wall of the motor housing 4 via the resin insulating sheet 11. As a result, the required capacity of the smoothing capacitor 7 can be reduced and the size thereof can be reduced. Further, the grounding bus bar and the power source bus bar are arranged in the resin molded plate portion of the bus bar built-in plate 81 so as to be overlapped in the thickness direction with a predetermined gap therebetween, and the same effect is achieved. (18) Outer frame portion 82 of bus bar built-in plate / outer frame portion 8
Since the power supply connector portion surrounding the DC power supply terminal portion is configured, the number of parts can be reduced. (19) Outer frame portion 82 of bus bar built-in plate / outer frame portion 8
Since the communication connector constitutes the communication connector portion surrounding the communication terminal composed of the tip of the communication bus bar, the number of parts can be reduced. (20) Outer frame portion 82 of bus bar built-in plate / outer frame portion 8
Since the motor connector portion 13 surrounding the AC output terminal portion is configured, the number of parts can be reduced. (21) Since the outer frame portion 82 is filled with resin, it is possible to improve electric insulation, moisture resistance, and vibration resistance of each connection portion and wiring. As the resin, a soft gel-like resin or a cured resin can be used.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of this inverter-integrated electric compressor.

FIG. 2 is a radial cross-sectional view of an inverter circuit portion of the inverter-integrated electric compressor shown in FIG.

FIG. 3 is an exploded perspective view showing a state in which a power MOS transistor module is mounted on a pedestal surface of a motor housing.

FIG. 4 is a plan view showing a state after mounting the power MOS transistor module 6 on the pedestal surface of the motor housing.

FIG. 5 is a perspective view showing a part of the bus bar in the bus bar built-in plate.

FIG. 6 is a plan view of the device showing a state where a printed circuit board is mounted.

[Explanation of symbols]

2 Motor Part 4 Motor Housing 6 Power MOS Transistor Module (Power Switching Element) 7 Smoothing Capacitor 8 Bus Bar Built-in Plate / Outer Frame 81 Bus Bar Built-in Plate 82 Outer Frame 17 Connector Housing 9 Printed Circuit Board 10 Cover Plate

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H02K 9/08 H02K 9/08 A 11/00 H02M 7/48 Z H02M 7/48 B60H 1/32 613G / / B60H 1/32 613 H02K 11/00 X (72) Inventor Hiroyuki Kawada 1-1 Chome, Showa-cho, Kariya City, Aichi Prefecture F-Term in DENSO CORPORATION (reference) 3H003 AC03 BE09 CD01 CF01 3H076 BB38 CC07 CC46 5H007 BB06 CA02 CB02 CB05 HA06 5H609 BB03 PP02 PP05 PP06 QQ03 QQ08 RR26 5H611 AA09 BB01 BB04 TT01 TT02 UA04

Claims (10)

[Claims] 1. A compressor section forming a part of a refrigeration cycle apparatus, a motor section that is integrally coupled to the compressor section to drive the compressor section, and a housing that houses the compressor section and the motor section. An inverter circuit unit having a number of power switching elements for converting the DC power into three-phase AC power to supply power to the motor unit, wherein the motor unit is a vehicle inverter cooled by a low-pressure refrigerant gas. In the integrated electric compressor, each of the power switching elements is separately configured by a discrete transistor having a side surface from which an electrode terminal projects and a bottom surface that is in direct contact with an outer peripheral surface of a peripheral wall of a motor portion surrounding portion of the housing. An electric compressor with a built-in inverter for vehicles. 2. The inverter-integrated electric compressor for a vehicle according to claim 1, wherein the outer peripheral surface of the peripheral wall of the housing has a pedestal portion having a flat pedestal surface to which the flat bottom surface of the discrete transistor is closely fixed. The discrete transistor includes, in the region of the pedestal surface that abuts the discrete transistor and in a portion where the peripheral wall of the housing is thick, is unevenly distributed in the circumferential direction and is perpendicular to the pedestal surface. An electric compressor integrated with an inverter for a vehicle, characterized in that the electric compressor is fastened to a screw hole formed in the peripheral wall. 3. The vehicular inverter-integrated electric compressor according to claim 2, wherein each electrode terminal of the discrete transistor protrudes in a circumferential direction in a direction in which a peripheral wall of the housing is thin on the pedestal surface. An electric compressor with a built-in inverter for vehicles. 4. The inverter integrated electric compressor for a vehicle according to claim 3, wherein each of the discrete transistors is closely fixed to the pedestal surface forming the same plane. compressor. 5. The vehicle-inverter integrated electric compressor according to claim 4, wherein the discrete transistors of different phases are axially adjacent to each other, and the pair of discrete transistors of the same phase have electrode terminals. Are arranged adjacent to each other in the circumferential direction so as to face each other in the circumferential direction, and a wiring area in which the electrode terminals of the pair of discrete transistors of the same phase project is formed between the pair of discrete transistors of the same phase facing each other. An electric compressor integrated with an inverter for a vehicle, which is characterized by having. 6. The vehicle-inverter integrated electric compressor according to claim 5, wherein the peripheral wall of the housing, which faces the wiring region in a radial direction, projects outward in a direction perpendicular to the pedestal surface with respect to the pedestal portion. Inverter-integrated electric compressor for vehicles characterized by 7. The vehicular inverter-integrated electric compressor according to claim 5, wherein a space for accommodating each of the discrete transistors is formed by being partitioned by an outer frame portion closely fixed to an outer peripheral surface of the peripheral wall of the housing. Inverter-integrated electric compressor for a vehicle, characterized by having a resin member that has been prepared. 8. The vehicle-inverter integrated electric compressor according to claim 5, further comprising an electrically insulating resin sheet disposed on an outer peripheral surface of the peripheral wall facing the wiring region. Integrated electric compressor. 9. The inverter-integrated electric compressor for a vehicle according to claim 5, further comprising a smoothing capacitor on a side opposite to the wiring region with the power switching element interposed therebetween. 10. The vehicular inverter-integrated electric compressor according to claim 9, further comprising an AC output terminal portion arranged on the opposite side of the smoothing capacitor with the power switching element interposed therebetween. An electric compressor integrated with a vehicle inverter.