Inverter device and inverter-integrated electric compressor provided with same

Abstract

Provided is an inverter device in which an insulation distance at a fixed position of a DC power input terminal to a substrate can be secured. This inverter device includes: a P line (15a) and an N line (15b); a substrate (12); a P connection pin (26a1) and an N connection pin (26b1) connected to the P line (15a) and the N line (15b), respectively; a P conduction path (28a) and an N conduction path (28b) connected to the P connection pin (26a1) and the N connection pin (26b1), respectively; and a P connection position (30a) and an N connection position (30b) connected to the P conduction path (28a) and the N conduction path (28b), respectively. When a center line (M1) connecting a center point (C1) between a P terminal (14a) and an N terminal (14b) and a center point (C2) between the P connection position (30a) and the N connection position (30b) is assumed, the P connection pin (26a1) is provided on the left side (12c) of the substrate (12), and the N connection pin (26b1) is provided on the upper side (12d) of the substrate, across the center line (M1).

Description

Inverter device and inverter-integrated electric compressor equipped with the same

[0001] The present disclosure relates to an inverter device and an inverter-integrated electric compressor including the inverter device.

[0002] As disclosed in Patent Document 1, an inverter-integrated electric compressor incorporating an inverter device is known as a compressor for air conditioning systems mounted on hybrid vehicles, electric vehicles, etc. This inverter-integrated electric compressor is configured such that an inverter accommodating section (inverter box) is provided in a housing that incorporates an electric motor and a compression mechanism, and an inverter device is incorporated inside the inverter box to convert DC power supplied from a power source into AC power and apply the AC power to the electric motor.

[0003] An inverter device generally includes a plurality of semiconductor switching elements such as IGBTs that convert DC power into AC power. The semiconductor switching elements generate high frequency currents, which generate noise.

[0004] In Patent Document 1, an LC series circuit in which a capacitor C and a coil L are connected in series is inserted to adjust impedance and reduce noise.

[0005] JP 2012-172611 A

[0006] However, even if noise can be reduced by inserting an LC series circuit as in Patent Document 1, further noise reduction is required.

[0007] In addition, the fixed position of the DC power input terminal to the board depends on the distance between the P terminal and N terminal of the connector part that leads the rectified DC power to the board, which poses the problem that the desired insulation distance cannot be secured.

[0008] The present disclosure has been made in consideration of the above circumstances, and aims to provide an inverter device that can ensure an insulation distance at the fixed position of the DC power input terminal to the board, and an inverter-integrated electric compressor equipped with the same.

[0009] Another object of the present invention is to provide an inverter device capable of reducing noise caused by semiconductor switching elements, and an inverter-integrated electric compressor including the inverter device.

[0010] an inverter device according to one aspect of the present disclosure, comprising: a semiconductor switching element that controls AC power supplied to an electric motor; a connector portion having a P-terminal and an N-terminal that supply DC power to the semiconductor switching element; P wiring and N wiring having one end electrically connected to the P-terminal and N-terminal of the connector portion, respectively; a substrate electrically connected to the P wiring and the N wiring; a P-fixed position and an N-fixed position that are provided on the substrate and electrically connected to the P wiring and the N wiring; a P-conductive path and an N-conductive path that are provided on the substrate and have one end connected to the P-fixed position and the N-fixed position and supply DC power to the semiconductor switching element; and a P-connection position and an N-connection position that are provided on the substrate and electrically connected to the other ends of the P-conductive path and the N-conductive path and electrically connected to each terminal of the semiconductor switching element, wherein, assuming a center line connecting the midpoint between the P-terminal and the N-terminal and the midpoint between the P-connection position and the N-connection position, the P-fixed position is provided on one side of the substrate, and the N-fixed position is provided on the other side of the substrate across the center line.

[0011] An inverter-integrated electric compressor according to one aspect of the present disclosure includes an electric motor, a compression mechanism driven by the electric motor to compress a refrigerant, a housing that accommodates the electric motor and the compression mechanism, and an inverter device according to any one of claims 1 to 3 attached to an outer wall of the housing.

[0012] A desired insulation distance can be ensured at the fixed position of the input terminal for DC power to the board.

[0013] Noise caused by semiconductor switching elements can be reduced.

[0014] 1 is a side view of an inverter-integrated electric compressor according to an embodiment of the present disclosure; FIG. 2 is a perspective view showing an IGBT; FIG. 3 is a side view showing the inverter-integrated electric compressor of FIG. 1 in a separated state; FIG. 4 is a front view showing the inside of an inverter box; FIG. 5 is a perspective view of the inverter box of FIG. 4 as seen from the back; FIG. 6 is a perspective view showing an enlarged lower part of the inverter box of FIG. 4; FIG. 7 is a rear view of the lower part of the inverter box of FIG. 4 as seen from the IGBT side, showing the board; FIG. 8 is a front view showing a state in which a board is installed in the inverter box of FIG. 4; FIG. 9 is a front view showing a comparative example of FIG. 9; and FIG. 10 is a front view showing a modified example of FIG. 9.

[0015] Hereinafter, an embodiment according to the present disclosure will be described with reference to the drawings. FIG. 1 shows an inverter-integrated electric compressor 1 according to one embodiment of the present disclosure. The inverter-integrated electric compressor 1 includes a housing 2 that forms an outer shell. The housing 2 is configured by integrally fastening together a motor housing 3 that houses an electric motor (not shown) and a compressor housing 4 that houses a compression mechanism (not shown) with bolts or the like. The motor housing 3 and the compressor housing 4 are pressure-resistant containers made of aluminum die-cast.

[0016] An electric motor and a compression mechanism (not shown) housed inside the housing 2 are connected via a motor shaft, and the compression mechanism is driven by rotation of the electric motor. The compression mechanism may be, for example, a scroll compression mechanism.

[0017] A refrigerant suction port (not shown) is provided at one end (e.g., the left side in FIG. 1) of the motor housing 3. Low-temperature, low-pressure refrigerant gas is drawn into the motor housing 3 from this refrigerant suction port, circulates around the electric motor along the motor axis (left-right direction in FIG. 1), and is then drawn into the compression mechanism where it is compressed. The high-temperature, high-pressure refrigerant gas compressed by the compression mechanism is discharged into the compressor housing 4 and then sent to the outside from a discharge port (not shown) provided at one end (e.g., the right side in FIG. 1) of the compressor housing 4.

[0018] The housing 2 is provided with a plurality of mounting legs (not shown) so that the inverter-integrated electric compressor 1 is fixedly installed in a motor room (or engine room) of a vehicle.

[0019] An inverter device 7 including an inverter box 9 is fixed to the rear end surface 3a (left end surface in FIG. 1 ) of the motor housing 3. The inverter box 9 can be opened and closed using a lid 9a, and is box-shaped with a peripheral wall 9b of a predetermined height and a base plate 9c. The inverter box 9 is sealed by fixing the lid 9a to the peripheral wall 9b with screws or the like.

[0020] The inverter box 9 accommodates electrical components that convert DC power supplied via a power cable from a power supply unit or battery (not shown) mounted on the vehicle into three-phase AC power and apply the AC power to the electric motor accommodated in the motor housing 3. Figure 1 shows a plurality of IGBTs 10, which are semiconductor switching elements.

[0021] The IGBT 10 includes an IGBT body 10a and terminals 10b provided on the IGBT body 10a. As shown in Fig. 2, each IGBT body 10a has three terminals 10b: an emitter, a collector, and a gate. The terminals 10b extend parallel to one another.

[0022] 1, the IGBT body 10a is fixed to the surface of the base plate 9c. The IGBT body 10a is cooled by the low-pressure refrigerant circulating within the motor housing 3 via the base plate 9c and the rear end surface 3a of the motor housing 3.

[0023] The tip of the terminal 10b of the IGBT 10 is electrically connected to the substrate 12 by solder or the like. The substrate 12 is fixed to the inverter box 9 in a state parallel to the surface of the base plate 9c at a predetermined distance. A switching circuit connected to the IGBT 10 is mounted on the substrate 12.

[0024] In addition to the circuit board 12, the inverter box 9 is provided with a PN terminal to which a high-voltage power supply line is connected, a UVW terminal for supplying three-phase AC power to the electric motor, an earth terminal, and the like.

[0025] 3 shows a separated state of the inverter-integrated electric compressor 1. As shown in the figure, the motor housing 3 and the inverter box 9 are separable. By assembling the inverter box 9 with the base plate 9c of the inverter box 9 in contact with the rear end surface 3a of the motor housing 3, the inverter-integrated electric compressor 1 shown in FIG. 1 is obtained.

[0026] 4 shows the inside of the inverter device 7 with the cover 9a (see FIG. 1) of the inverter box 9 removed. In this figure, the circuit board 12 (see FIG. 1) has been removed.

[0027] 4, the lower part of the inverter box 9 is a cylindrical portion 9d that is cylindrical in shape to match the outer shape of the motor housing 3. A rectangular portion 9e is connected to the upper part of the cylindrical portion 9d.

[0028] A P-N connector (connector portion) 14, to which DC power is supplied, is provided at an upper corner of the rectangular portion 9e. The P-N connector 14 is attached to the base plate 9c of the inverter box 9. One end of a P wiring 15a and one end of an N wiring 15b are connected to the P terminal 14a and the N terminal 14b of the P-N connector 14, respectively. In FIG. 4, the P wiring 15a extends downward, and the N wiring 15b extends laterally (to the right). The other ends of the P wiring 15a and the N wiring 15b are fixed to a P connection part 26a and an N connection part 26b. A P connection pin (P fixed position) 26a1 and an N connection pin (N fixed position) 26b1 are erected on the P connection part 26a and the N connection part 26b, respectively. The P connection pin 26a1 and the N connection pin 26b1 are inserted into holes formed in the substrate 12 (see FIG. 8) and electrically connected by solder or the like.

[0029] An inductor coil 16 and a smoothing capacitor 17 are provided below the P-N connector 14. As shown in Figure 5, the inductor coil 16 and the smoothing capacitor 17 are housed in a recess 19 formed in the base plate 9c. The recess 19 is assembled so that its bottom 19a contacts the rear end surface 3a (see Figure 3) of the motor housing 3. This allows the inductor coil 16 and the smoothing capacitor 17 to be cooled.

[0030] 4, a UVW busbar assembly 18 is provided below the inductor coil 16 and the smoothing capacitor 17. The UVW busbar assembly 18 is provided between the rectangular portion 9e and the cylindrical portion 9d.

[0031] Six IGBTs 10 are provided in the cylindrical portion 9d of the inverter box 9. Each IGBT body 10a is fixed to a front surface 9c1(F) of an IGBT fixing plate 9c1 of the base plate 9c with a fixing screw 20. The IGBT fixing plate 9c1 has a generally rectangular shape extending upward from the lower end of the peripheral wall 9b of the inverter box 9. Three IGBTs 10 are arranged on each side of the rectangular IGBT fixing plate 9c1. The IGBTs 10 are arranged so that the terminals 10b of the IGBTs 10 facing each other on the left and right sides face each other. As shown in FIG. 5, the rear surface 9c1(R) of the IGBT fixing plate 9c1, which is the surface on which the IGBTs 10 are not fixed, is assembled so that its entire surface contacts the rear end surface 3a of the motor housing 3 (see FIG. 3).

[0032] As shown in Fig. 4, connecting portions 9c2 extending diagonally upward and to the sides are provided on both sides of the upper portion of the IGBT fixing plate 9c1. The upper portion of the IGBT fixing plate 9c1 is supported by each connecting portion 9c2. The other end of each connecting portion 9c2 is connected to the peripheral wall 9b. As shown in Fig. 5, the rear surface 9c2(R) of each connecting portion 9c2 is assembled so that its entirety contacts the rear end surface 3a of the motor housing 3 (see Fig. 3).

[0033] 6, base plate openings 22 are formed on the left and right sides and on the top of the IGBT fixing plate 9c1. The base plate 9c is not present at the position of each base plate opening 22 and has been removed. Each base plate opening 22 allows the interior of the inverter box 9 to be viewed from the back side of the base plate 9c, allowing the IGBT 10 (particularly the terminals 10b) to be inspected.

[0034] As shown in Figure 5, a seal portion 9c3 is provided around the cylindrical portion 9d so as to partially protrude from the back surface of the base plate 9c. The seal portion 9c3 is provided in a generally annular shape so as to surround and cover each base plate opening 22. When the inverter box 9 is attached to the rear end surface 3a of the motor housing 3 (see Figure 3), the seal portion 9c3 prevents moisture and the like from entering the inverter box 9 from the outside through the base plate opening 22.

[0035] 7 shows the substrate 12 viewed from the IGBT 10 side with the IGBT fixing plate 9c1 removed. The substrate 12 is fixed to the inverter box 9 using the fixing holes 12a. Three substrate fixing screws 24 for fixing the substrate 12 using the fixing holes 12a are shown in FIG.

[0036] Fig. 8 shows the state in which the board 12 is installed on the inverter box 9 shown in Fig. 4. The board 12 has a substantially rectangular shape when viewed from above as shown in Fig. 8. The board 12 is fixed to the inverter box 9 by board fixing screws 12b that are provided to pass through fixing holes 12a (see Fig. 7) formed in the board 12. In Fig. 8, six board fixing screws 12b are used, but the number is not limited to this, and four may be provided at the four corners of the board 12, for example.

[0037] 8, the P connection pin 26a1 is located on the left side 12c of the substrate 12, and the N connection pin 26b1 is located on the top side 12d of the substrate 12. The P-N connector 14 is located above the left end of the top side 12d of the substrate 12. Eighteen terminals 10b (3 x 3 x 2 rows) of the IGBT 10 (see FIG. 4) are shown below the substrate 12.

[0038] The P connection pin 26a1 and the N connection pin 26b1 are electrically connected via a conductive path formed on the substrate 12 to a connection position such as a land to which the terminal 10b is attached.

[0039] 9 schematically shows the electrical paths from the P connection pin 26a1 and the N connection pin 26b1 to the terminal 10b. With respect to a center line M1 connecting a center point C1 between the P terminal 14a and the N terminal 14b and a center point C2 between the P connection position 30a and the N connection position 30b, the P connection pin 26a1 is provided on one side (the left side 12c) and the N connection pin 26b1 is provided on the other side (the top side 12d). The center point C2 is set at the end of the P connection position 30a and the N connection position 30b on the conductive paths 28a, 28b side.

[0040] In this way, since the P connection pin 26a1 is provided on the left side 12c of the substrate 12 and the N connection pin 26b1 is provided on the top side 12d of the substrate 12, the distance L1 between the P connection pin 26a1 and the N connection pin 26b1 can be made larger than the distance L0 between the P terminal 14a and the N terminal 14b. This makes it possible to ensure a desired insulation distance at the position where DC power is supplied to the substrate 12.

[0041] A comparative example is shown in Fig. 10. As shown in the figure, when the P connection pin 26a1 and the N connection pin 26b1 are provided near the P terminal 14a and the N terminal 14b, the distance between the P connection pin 26a1 and the N connection pin 26b1 becomes equal to the distance L0 between the P terminal 14a and the N terminal 14b, and the desired insulation distance cannot be ensured.

[0042] As shown in FIG. 9 , the P conductive path 28a electrically connecting the P connection pin 26a1 to the P connection position 30a and the N conductive path 28b electrically connecting the N connection pin 26b1 to the N connection position 30b are arranged at equal distances. This allows the circuit constants of the P path from the P terminal 14a to the P connection position 30a via the P connection pin 26a1 and the P conductive path 28a to be equal to the circuit constants of the N path from the N terminal 14b to the N connection position 30b via the N connection pin 26b1 and the N conductive path 28b. Because the impedances of the P wiring 15a and the N wiring 15b are sufficiently smaller than the impedances of the P conductive path 28a and the N conductive path 28b, the difference in length between the P wiring 15a and the N wiring 15b does not have a significant effect on determining the circuit constants. Therefore, it is important to make the lengths of the P conductive path 28a and the N conductive path 28b equal.

[0043] The effects of the present embodiment described above are as follows: The P connection pin 26a1 is provided on one side (left side 12c) of the board, and the N connection pin 26b1 is provided on the other side (top side 12d) across the center line M1. This increases the distance L1 between the P connection pin 26a1 and the N connection pin 26b1, ensuring the desired insulation distance.

[0044] The circuit constant of the P path from the P terminal 14a via the P connection pin 26a1 and the P conductive path 28a to the P connection position 30a can be made equal to the circuit constant of the N path from the N terminal 14b via the N connection pin 26b1 and the N conductive path 28b to the N connection position 30b, thereby reducing noise.

[0045] Note that the circuit constants of the P path and the N path being equivalent naturally includes all of the following: the impedances formed by the electronic components on each path being equivalent, the impedances formed by the patterns on the electric circuit on each path being equivalent, and the circuit constants being equivalent due to the combined impedances of the impedances formed by the electronic components and the impedances formed by the patterns on the electric circuit being equivalent.

[0046] 11, the positions of the connection pins 26a1 and 26b1 may be determined so that the distance L3 between the P connection pin 26a1 and the P connection position 30a is equal to the distance L4 between the N connection pin 26b1 and the N connection position 30b. In the figure, the P connection pin 26a1 is provided on the left side 12c of the substrate 12, and the N connection pin 26b1 is provided on the right side 12e of the substrate 12. The P connection pin 26a1 and the N connection pin 26b1 are provided at positions symmetrical with respect to a center line M2 that passes through the centers of the two rows of terminals 10b.

[0047] Since the distance L3 between the P connection pin 26a1 and the P connection position 30a and the distance L4 between the N connection pin 26b1 and the N connection position 30b are equal, it is easy to design the distance between the P conductive path 28a and the N conductive path 28b to be equal. This allows the circuit constants to be equalized, thereby reducing noise. Although the lengths of the P wiring 15a and the N wiring 15b are different in the figure, the impedances of the wirings 15a and 15b are sufficiently smaller than the impedances of the P conductive path 28a and the N conductive path 28b, so the difference in length between the P wiring 15a and the N wiring 15b does not have a significant impact on determining the circuit constants.

[0048] Furthermore, even if it is not possible to set the P connection pin 26a1 and the N connection pin 26b1 at positions where the distances L3 and L4 are equal, as in FIG. 11, the lengths of the P conductive path 28a and the N conductive path 28b can be adjusted to make the circuit constant of the P path from the P terminal 14a via the P connection pin 26a1 and the P conductive path 28a to the P connection position 30a equal to the circuit constant of the N path from the N terminal 14b via the N connection pin 26b1 and the N conductive path 28b to the N connection position 30b.

[0049] The inverter device and the inverter-integrated electric compressor described in each of the above-described embodiments can be understood, for example, as follows.

[0050] The inverter device according to a first aspect of the present disclosure includes a semiconductor switching element (10) for controlling AC power supplied to an electric motor, a connector portion (14) having a P terminal (14a) and an N terminal (14b) for supplying DC power to the semiconductor switching element, a P wiring (15a) and an N wiring (15b) having one end electrically connected to the P terminal and the N terminal of the connector portion, respectively, a substrate (12) electrically connected to the P wiring and the N wiring, a P fixing position (26a1) and an N fixing position (26b1) provided on the substrate and electrically connected to the P wiring and the N wiring, and a P fixing position (26a1) and an N fixing position (26b1) provided on the substrate and electrically connected to the P fixing position and the N fixing position. The semiconductor switching element is provided with a P conductive path (28a) and an N conductive path (28b) whose ends are connected to supply DC power to the semiconductor switching element, and a P connection position (30a) and an N connection position (30b) which are provided on the substrate and electrically connected to the other ends of the P conductive path and the N conductive path and also electrically connected to each terminal of the semiconductor switching element, and when a center line (M1) is assumed to connect a center point (C1) between the P terminal and the N terminal and a center point (C2) between the P connection position and the N connection position, the P fixed position is provided on one side (12c) of the substrate, and the N fixed position is provided on the other side (12d) of the substrate across the center line.

[0051] The P-fixing position is located on one side of the substrate, and the N-fixing position is located on the other side across the center line. This increases the distance between the P-fixing position and the N-fixing position, thereby ensuring a desired insulation distance. The semiconductor switching element is, for example, an IGBT.

[0052] In the inverter device according to the second aspect of the present disclosure, in the first aspect, the circuit constants of the P path from the P terminal via the P fixed position to the P connection position and the N path from the N terminal via the N fixed position to the N connection position are made equivalent.

[0053] By making the circuit constants of the P path and the N path equal, noise can be reduced.

[0054] In the inverter device according to a third aspect of the present disclosure, in the first or second aspect, the distance of the P conductive path and the distance of the N conductive path are equal to each other.

[0055] By making the distance of the P conductive path equal to the distance of the N conductive path, the circuit constants of the P path and the N path can be made equal, which makes it possible to make the circuit constants equal and reduce noise.

[0056] In the inverter device according to the fourth aspect of the present disclosure, in any of the first to third aspects, the distance (L3) between the P fixed position and the P connection position is equal to the distance (L4) between the N fixed position and the N connection position.

[0057] Since the distance between the P-fixed position and the P-connected position is the same as the distance between the N-fixed position and the N-connected position, it is easy to design the distance of the P-conductive path to be the same as the distance of the N-conductive path, which allows the circuit constants to be the same and reduces noise.

[0058] The inverter-integrated electric compressor according to the first aspect of the present disclosure includes an electric motor, a compression mechanism driven by the electric motor to compress a refrigerant, a housing (2) that accommodates the electric motor and the compression mechanism, and any one of the above-mentioned inverter devices attached to an outer wall of the housing.

[0059] REFERENCE SIGNS LIST 1 inverter-integrated electric compressor 2 housing 3 motor housing 3a rear end surface 4 compressor housing 7 inverter device 9 inverter box 9a lid portion 9b surrounding wall 9c base plate 9c1 IGBT fixing plate 9c1 (F) front surface 9c1 (R) rear surface 9c2 connection portion 9c2 (R) rear surface 9c3 seal portion 9d cylindrical portion 9e rectangular portion 10 IGBT (semiconductor switching element) 10a IGBT body 10b terminal 12 substrate 12a fixing hole 12b substrate fixing screw 12c left side 12d upper side 14 P-N connector (connector portion) 14a P terminal 14b N terminal 15a P wiring 15b N wiring 16 inductor coil 17 smoothing capacitor 18 UVW busbar assembly 19 Recess 19a Bottom 20 Fixing screw 22 Base plate opening 24 Board fixing screw 26a P connection part 26a1 P connection pin (P fixing position) 26b N connection part 26b1 N connection pin (N fixing position) 28a P conductive path 28b N conductive path 30a P connection position 30b N connection position C1, C2 Center point M1, M2 Center line

Claims

1. A semiconductor switching element that controls AC power supplied to an electric motor; a connector portion having a P terminal and an N terminal for supplying DC power to the semiconductor switching element; P wiring and N wiring having one end electrically connected to the P terminal and the N terminal of the connector portion, respectively; a substrate electrically connected to the P wiring and the N wiring; P fixing positions and N fixing positions provided on the substrate and electrically connected to the P wiring and the N wiring; P conducting paths and N conducting paths provided on the substrate and having one end connected to the P fixing positions and the N fixing positions for supplying DC power to the semiconductor switching element; and P connecting positions and N connecting positions provided on the substrate and electrically connected to the other ends of the P conducting paths and the N conducting paths and electrically connected to each terminal of the semiconductor switching element, An inverter device in which, assuming a center line connecting the midpoint between the P terminal and the N terminal and the midpoint between the P connection position and the N connection position, the P fixed position is provided on one side of the board, and the N fixed position is provided on the other side of the board across the center line.

2. The inverter device according to claim 1, wherein the circuit constants of the P path from the P terminal via the P fixed position to the P connection position and the N path from the N terminal via the N fixed position to the N connection position are equivalent.

3. The inverter device according to claim 1, wherein the distance of the P conductive path is equal to the distance of the N conductive path.

4. The inverter device according to claim 1, wherein the distance between the P fixed position and the P connecting position is equal to the distance between the N fixed position and the N connecting position.

5. An inverter-integrated electric compressor comprising: an electric motor; a compression mechanism driven by the electric motor to compress a refrigerant; a housing accommodating the electric motor and the compression mechanism; and an inverter device according to any one of claims 1 to 4 attached to an outer wall of the housing.

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