Electric compressor

Abstract

To provide an electric compressor that can improve heat dissipation efficiency of a circuit board while restraining an increase in cost.SOLUTION: An inverter device 50 is fixed to a housing 10 by a plurality of fastening members 80, and comprises a circuit board 51 comprising a first conductive part 91 and a second conductive part 92, and an electric circuit 52. The electric circuit 52 includes a terminal T as a first heat generation part F1. The second conductive part 92 is electrically connected to the housing 10 via a first proximity fastening member 81 closest to the first heat generation part F1. The electric circuit 52 comprises a first capacitor group 60 electrically connecting the first conductive part 91 and the second conductive part 92. The first capacitor group 60 comprises a plurality of first capacitors 61A and 61B, and a first metal frame body 62 holding the plurality of first capacitors electrically connected to each other. A portion of the first capacitor group 60 is arranged on a first virtual straight line L1 connecting a first connection point C1 between the first heat generation part F1 and the first conductive part 91, and the first proximity fastening member 81.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an electric compressor.

Background Art

[0002] Patent Document 1 discloses an example of a conventional electric compressor. This electric compressor includes a compression part, an electric motor, an inverter device, and a housing.

[0003] The compression part compresses a fluid. The electric motor drives the compression part. The inverter device drives the electric motor. The housing is made of metal and houses the compression part, the electric motor, and the inverter device. The inverter device has a circuit board, an inverter circuit, and a filter circuit.

[0004] The circuit board is fixed to the housing by a plurality of metal fastening members. The circuit board has a conductive pattern including a first conductive part, a second conductive part, and a third conductive part. The inverter circuit is mounted on the first conductive part and converts DC power into AC power. The filter circuit is mounted on the second conductive part and is disposed on the input side of the inverter circuit to reduce noise included in the DC current input to the inverter circuit.

[0005] The filter circuit has a capacitor group. The capacitor group has a pair of first capacitors that electrically connect the first conductive part and the third conductive part where the inverter circuit is provided, and a pair of second capacitors that electrically connect the second conductive part and the third conductive part where the filter circuit is provided.

[0006] The third conductive part is electrically connected to the housing via the fastening member closest to the filter circuit among the plurality of fastening members.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

[0008] Incidentally, in the design of electrical products such as inverter devices, it is important to improve the heat dissipation efficiency of the circuit board. In the conventional electric compressor described above, the heat generated in the inverter circuit and filter circuit is transferred from the first and second conductive parts to the third conductive part via a group of capacitors, and can also be dissipated from the third conductive part to the housing via fastening members.

[0009] However, in the conventional electric compressor described above, each capacitor constituting the capacitor group is scattered across the circuit board at locations where it can be placed. As a result, the distance from the heat source to each capacitor differs, leading to an imbalance in the heat transferred from the heat source to the capacitors. Therefore, in the conventional electric compressor described above, heat dissipation is unbalanced, and improving the heat dissipation efficiency of the circuit board is not always easy. To improve the heat dissipation efficiency of the circuit board, it is conceivable to use capacitors with a wide operating temperature range or to add a cooling mechanism for the capacitors, but in this case, costs will increase.

[0010] This invention has been made in view of the above-mentioned conventional circumstances, and aims to solve the problem of providing an electric compressor that can improve the heat dissipation efficiency of a circuit board while suppressing an increase in cost. [Means for solving the problem]

[0011] The electric compressor of the present invention comprises a compression section for compressing a fluid, An electric motor that drives the compression section, An inverter device that drives the aforementioned electric motor, An electric compressor comprising a compression unit, an electric motor, and a metal housing that accommodates the inverter device, The inverter device is, A circuit board having a conductive pattern including a first conductive portion and a second conductive portion is fixed to the housing by a plurality of metal fastening members, The aforementioned Electrically connected to the conductive pattern It has an electrical circuit, The aforementioned electrical circuit , electrically connected to the first conductive part Including the first heating element, The second conductive portion is electrically connected to the housing via the first proximity fastening member, which is the closest to the first heating portion among the plurality of fastening members. The aforementioned electrical circuit is It has a filter circuit, The aforementioned filter circuit is It has a first group of capacitors that electrically connect the first conductive part and the second conductive part, The first group of capacitors is arranged in a line facing each other. External electrodes are provided at both ends. A plurality of first capacitors are held in a state in which the plurality of first capacitors are electrically connected to each other. a pair It has a first metal frame, The plurality of first capacitors are held by the pair of first metal frames on the circuit board, stacked vertically with their main surfaces facing each other. Each of the pair of first metal frames has an L-shaped cross-section and includes a connecting portion connected to the conductive pattern and a connecting portion that rises from one end of the connecting portion and electrically connects the external electrodes of each of the first capacitors stacked vertically. The connecting portion of one of the pair of first metal frames is electrically connected to the first conductive portion, and the connecting portion of the other of the pair of first metal frames is electrically connected to the second conductive portion. A portion of the first capacitor group is arranged on a first virtual straight line connecting the first connection point between the first heating element and the first conductive element and the first proximity fastening member.

[0012] In the electric compressor of the present invention, a group of first capacitors connecting a first conductive part and a second conductive part is arranged on a first virtual straight line connecting a first connection point between a first heating part and a first conductive part and a first proximity fastening member closest to the first heating part. Therefore, the heat generated in the first heating part is transmitted from the first conductive part where the first heating part is located, through the group of first capacitors to the second conductive part, and then to the first proximity fastening member. In other words, the heat generated in the first heating part is transmitted to the first proximity fastening member through a shorter heat dissipation path compared to when the group of first capacitors is not arranged on the first virtual straight line. The heat transmitted to the first proximity fastening member can be dissipated to the housing. As a result, the heat dissipation efficiency is improved compared to when the group of first capacitors is not arranged on the first virtual straight line, the heat load on the group of first capacitors can be reduced, it becomes possible to use capacitors with a narrow operating temperature range, and the increase in cost can be suppressed. In addition, in the group of first capacitors, a plurality of first capacitors are held by a first metal frame. If multiple first capacitors are scattered, an imbalance in heat dissipation is likely to occur. However, if multiple first capacitors are grouped together in one place by a first metal frame, this imbalance in heat dissipation can be suppressed. This reduces the thermal load on multiple first capacitors, making it possible to use capacitors with a narrower operating temperature range, and thus keeping cost increases down.

[0013] Therefore, according to the electric compressor of the present invention, it is possible to improve the heat dissipation efficiency of the circuit board while suppressing an increase in cost.

[0014] The first heating element is preferably a terminal of the power element, and the first virtual straight line preferably connects the first connection point between the terminal and the first conductive part and the first proximity fastening member.

[0015] In this case, the heat generated at the terminals of the power element can be transferred to the first proximity fastening member via a shorter heat dissipation path compared to the case where the first group of capacitors is not arranged on the first virtual straight line.

[0016] The conductive pattern may include a third conductive part. Also, the electrical circuit , electrically connected to the third conductive part It may include a second heating part. The second conductive part may be electrically connected to the housing via a second proximity fastening member that is the closest to the second heating part among the plurality of fastening members. filter Preferably, the circuit has a second capacitor group that electrically connects the third conductive part and the second conductive part. And the second capacitor group is arranged side by side facing each other External electrodes are provided at both ends. a plurality of second capacitors, and holds the plurality of second capacitors in a state where they are electrically connected to each other a pair It preferably has a second metal frame. Furthermore, multiple second capacitors can be held by a pair of second metal frames on a circuit board, stacked vertically with their main surfaces facing each other. Each of the pair of second metal frames may have an L-shaped cross-section and include a connection portion connected to a conductive pattern, and a connecting portion that rises from one end of the connection portion and electrically connects the external electrodes of the stacked second capacitors. Preferably, one connection portion of the pair of second metal frames is electrically connected to the third conductive portion, and the other connection portion of the pair of second metal frames is electrically connected to the second conductive portion. Also, preferably, a part of the second capacitor group is arranged on a second virtual straight line connecting the second connection point between the second heating part and the third conductive part and the second proximity fastening member.

[0017] In this case, a second capacitor group that connects the third conductive part and the second conductive part is arranged on a second virtual straight line connecting the second connection point between the second heating part and the third conductive part and the second proximity fastening member closest to the second heating part. Therefore, the heat generated in the second heating part is transmitted from, for example, the third conductive part where the second heating part is provided to the second conductive part through the second capacitor group, and then transmitted to the second proximity fastening member. That is, the heat generated in the second heating part is transmitted to the second proximity fastening member through a shorter heat dissipation path compared to the case where the second capacitor group is not arranged on the second virtual straight line. The heat transmitted to the second proximity fastening member can escape to the housing. As a result, the heat dissipation efficiency is improved compared to the case where the second capacitor group is not arranged on the second virtual straight line, so the heat load on the second capacitor group can be reduced, and it becomes possible to use a capacitor with a narrow operating temperature range, suppressing an increase in cost. Also, in the second capacitor group, since the plurality of second capacitors are grouped together at one place by the second metal frame, the heat dissipation imbalance can be suppressed compared to the case where the plurality of second capacitors are scattered. As a result, the heat load on the plurality of second capacitors can be reduced, and it becomes possible to use a capacitor with a narrow operating temperature range, suppressing an increase in cost.

Advantages of the Invention

[0018] According to the electric compressor of the present invention, it is possible to improve the heat dissipation efficiency of the circuit board while keeping costs down. [Brief explanation of the drawing]

[0019] [Figure 1] Figure 1 is a schematic side view showing the cross-sectional structure of the main part of the electric compressor of the embodiment. [Figure 2] Figure 2 is a circuit diagram showing the electrical configuration of the electric compressor in the embodiment. [Figure 3] Figure 3 is a schematic plan view showing the circuit board of the electric compressor of the embodiment. [Figure 4] Figure 4 is a perspective view of the capacitor group relating to the electric compressor of the embodiment. [Modes for carrying out the invention]

[0020] The following describes embodiments of the present invention with reference to the drawings.

[0021] The electric compressor in this embodiment is an on-board electric compressor installed in a vehicle as part of the vehicle's air conditioning system.

[0022] As shown in Figure 1, this electric compressor (hereinafter simply referred to as "compressor") comprises a housing 10, a rotating shaft 20, a compression unit 30, an electric motor 40, and an inverter device 50.

[0023] The housing 10 is made of metal. For example, the housing 10 is made of an aluminum alloy. However, the material of the housing 10 can be any metal that has heat conductivity. The housing 10 is in contact with the vehicle body (not shown).

[0024] The housing 10 includes an intake housing 12, a discharge housing 14, and an inverter housing 16. The intake housing 12 has a disc-shaped first end wall 12a, a cylindrical first circumferential wall 12b, and an intake port 12c. The first circumferential wall 12b extends from the outer circumference of the first end wall 12a toward the discharge housing 14. The intake port 12c penetrates the first circumferential wall 12b. Piping is connected to the intake port 12c. As a result, low-temperature, low-pressure refrigerant gas that has passed through the evaporator is drawn into the intake port 12c through the piping. The refrigerant gas is an example of a "fluid" in this invention.

[0025] The discharge housing 14 is assembled to the suction housing 12 with the opening of the suction housing 12 closed. As a result, the suction housing 12 and the discharge housing 14 form a motor housing chamber 17 within the housing 10. The discharge housing 14 has a discharge port 14a. Piping (not shown) is connected to the discharge port 14a, and the discharge port 14a allows the refrigerant gas compressed in the compression unit 30 to flow toward the condenser. Note that the piping, evaporator, and condenser are not shown.

[0026] The inverter housing 16 has a plate-shaped second end wall 16a and a cylindrical second circumferential wall 16b. The inverter housing 16 is attached to the first end wall 12a of the intake housing 12 with the open end of the second circumferential wall 16b abutting against the first end wall 12a. The opening of the second circumferential wall 16b of the inverter housing 16 is closed by the second end wall 16a. As a result, the first end wall 12a and the inverter housing 16 form an inverter housing chamber 18. The housing 10 has an inverter housing chamber 18. The first end wall 12a separates the motor housing chamber 17 from the inverter housing chamber 18.

[0027] The rotating shaft 20 is rotatably supported by the housing 10. The rotating shaft 20 is housed in the motor housing chamber 17 with its axial direction aligned with the axial direction of the first circumferential wall 12b.

[0028] The compression unit 30 is housed within the intake housing 12. The compression unit 30 is a scroll type, consisting of, for example, a fixed scroll (not shown) fixed within the intake housing 12 and a movable scroll (not shown) positioned opposite the fixed scroll. The compression unit 30 is located within the motor housing chamber 17, closer to the discharge port 14a than to the intake port 12c. The compression unit 30 is connected to the rotating shaft 20. The compression unit 30 is driven by the rotation of the rotating shaft 20 to compress the refrigerant gas.

[0029] The electric motor 40 is housed in the motor housing chamber 17. The electric motor 40 is positioned between the compression section 30 and the first end wall 12a within the motor housing chamber 17. The electric motor 40 has, for example, a cylindrical rotor 42 and a stator 44. The rotor 42 is fixed to the rotating shaft 20. This configures the rotating shaft 20 to rotate integrally with the rotor 42. The stator 44 is fixed to the first circumferential wall 12b of the intake housing 12. The rotor 42 and the stator 44 face each other in the radial direction of the rotating shaft 20.

[0030] The stator 44 is wound with three-phase coils 46u, 46v, and 46w. The three-phase coils 46u, 46v, and 46w are connected in a Y-connection, for example. However, the connection configuration of the three-phase coils 46u, 46v, and 46w is not limited to a Y-connection and is arbitrary. The connection configuration of the three-phase coils 46u, 46v, and 46w may be, for example, a delta connection.

[0031] The rotor 42 rotates when the three-phase coils 46u, 46v, and 46w are energized in a predetermined pattern. As the rotor 42 rotates, the rotating shaft 20 rotates. This drives the compression unit 30. The refrigerant gas flowing from the evaporator (not shown) is drawn into the motor housing chamber 17 through the intake port 12c. The motor housing chamber 17 also serves as the intake chamber.

[0032] A connector 48 is attached to the inverter housing 16. The connector 48 is a terminal for supplying power from the onboard energy storage device B to the inverter device 50. The connector 48 is electrically connected to the energy storage device B.

[0033] The inverter device 50 is housed in the inverter housing 18. The inverter device 50 is electrically connected to the energy storage device B via a connector 48.

[0034] The inverter device 50 has a circuit board 51. The circuit board 51 is housed in the inverter housing chamber 18. The circuit board 51 is positioned opposite the first end wall 12a at a predetermined distance in the axial direction of the rotation shaft 20. The circuit board 51 is housed in the inverter housing chamber 18 with its thickness direction aligned with the axial direction of the rotation shaft 20. The circuit board 51 is fixed to the first end wall 12a by a plurality of metal bolts 80. The bolts 80 are an example of a "fastening member" in the present invention.

[0035] As shown in Figure 2, the inverter device 50 comprises an inverter circuit 52, a filter circuit 53, and a control unit 54. The inverter circuit 52 and the filter circuit 53 are examples of "electrical circuits" in the present invention.

[0036] The inverter circuit 52 drives the electric motor 40. The inverter circuit 52 comprises a positive busbar Lp, a negative busbar Ln, six switching elements Q1 to Q6, and six diodes D1 to D6. IGBTs are used as the switching elements Q1 to Q6. The switching elements Q1 to Q6 are examples of "power elements" in this invention.

[0037] Between the positive bus Lp and the negative bus Ln, switching elements Q1 and Q2, which constitute the u-phase upper arm and u-phase lower arm respectively, are connected in series. Between the positive bus Lp and the negative bus Ln, switching elements Q3 and Q4, which constitute the v-phase upper arm and u-phase lower arm respectively, are connected in series. Between the positive bus Lp and the negative bus Ln, switching elements Q5 and Q6, which constitute the w-phase upper arm and u-phase lower arm respectively, are connected in series. Diodes D1 to D6 are connected in antiparallel to switching elements Q1 to Q6.

[0038] Switching element Q1 and switching element Q2 are connected to the u-phase coil 46u of the electric motor 40. Switching element Q3 and switching element Q4 are connected to the v-phase coil 46v of the electric motor 40. Switching element Q5 and switching element Q6 are connected to the w-phase coil 46w of the electric motor 40. The inverter circuit 52, which has switching elements Q1 to Q6 that constitute the upper and lower arms, is configured to convert DC voltage to AC voltage and output it to the electric motor 40 in accordance with the switching operation of switching elements Q1 to Q6. Therefore, the inverter circuit 52 converts DC power input from the energy storage device B via the connector 48 into AC power.

[0039] The control unit 54 controls the switching operation of each switching element Q1 to Q6. The control unit 54 can be implemented, for example, by one or more dedicated hardware circuits and / or one or more processors (control circuits) that operate according to a computer program (software). The processor includes a CPU and memory such as RAM and ROM, and the memory stores, for example, program code or instructions configured to cause the processor to execute various processes. Memory, or computer-readable media, includes any available media that can be accessed by a general-purpose or dedicated computer.

[0040] The control unit 54 periodically turns each switching element Q1 to Q6 ON / OFF. More specifically, the control unit 54 PWM controls each switching element Q1 to Q6 based on a command from the air conditioning ECU (not shown). The control unit 54 generates a control signal using the carrier signal and the command voltage value signal. Then, the control unit 54 converts DC power to AC power by controlling the ON / OFF state of each switching element Q1 to Q6 using the generated control signal.

[0041] The filter circuit 53 is located on the connector 48 side relative to the inverter circuit 52. The filter circuit 53 is located between the connector 48 and the inverter circuit 52. The filter circuit 53 reduces noise contained in the DC power input from the connector 48 to the inverter circuit 52. The filter circuit 53 also reduces noise generated from the inverter circuit 52 and flowing toward the connector 48. The noise generated from the inverter circuit 52 is, for example, noise generated in conjunction with the switching operation of each switching element Q1 to Q6.

[0042] The filter circuit 53 is connected to the positive bus Lp and the negative bus Ln. Therefore, the filter circuit 53 is located on the input side of the inverter circuit 52. The filter circuit 53 includes a smoothing capacitor 55, an inductor 56, a first capacitor group 60, and a second capacitor group 70.

[0043] The smoothing capacitor 55 is an X capacitor connected in parallel to the inverter circuit 52. Specifically, the smoothing capacitor 55 is connected to the positive bus Lp and the negative bus Ln.

[0044] Coil 56 is, for example, a common-mode choke coil. Coil 56 is provided on the input side of the inverter circuit 52. Coil 56 has a leakage inductance L. The leakage inductance L functions as a choke coil against normal-mode noise. Therefore, the leakage inductance L, together with the smoothing capacitor 55, constitutes a low-pass filter circuit that removes normal-mode noise. As a result, coil 56 reduces the noise contained in the DC power. Thus, the filter circuit 53 removes common-mode noise and normal-mode noise.

[0045] The filter circuit 53 has two first capacitor groups 60. The two first capacitor groups 60 are connected in series. The space between the two first capacitor groups 60 is grounded to the vehicle body via the housing 10. The two first capacitor groups 60 are located on the inverter circuit 52 side relative to the coil 56. The two first capacitor groups 60 are connected in parallel with respect to the coil 56. The two first capacitor groups 60 are connected in parallel with respect to the smoothing capacitor 55. The two first capacitor groups 60 are located between the coil 56 and the smoothing capacitor 55.

[0046] The filter circuit 53 has two second capacitor groups 70. The two second capacitor groups 70 are connected in series. The two second capacitor groups 70 are grounded to the vehicle body via the housing 10. The two second capacitor groups 70 are located on the connector 48 side relative to the coil 56. The two second capacitor groups 70 are connected in parallel to the connector 48. The two second capacitor groups 70 are connected in parallel to the coil 56. The two second capacitor groups 70 are located between the connector 48 and the coil 56.

[0047] As shown in Figure 3, the coil 56, the first capacitor group 60, and the second capacitor group 70 are mounted on the circuit board 51. For the sake of explanation, only one of the first capacitor group 60 and the second capacitor group 70 are shown in Figure 3. Although the smoothing capacitor 55 is also mounted on the circuit board 51, it is omitted from the illustration in Figure 3 for the sake of explanation.

[0048] A conductive pattern 90 is formed on the circuit board 51. The conductive pattern 90 has a first conductive part 91, a second conductive part 92, and a third conductive part 93. The circuit board 51 also has an insulating layer 94. The insulating layer 94 is formed of, for example, a plate-shaped glass epoxy resin. The conductive pattern 90 is formed of a sheet-shaped copper foil. The conductive pattern 90 is provided on the surface of the insulating layer 94. The first conductive part 91, the second conductive part 92, and the third conductive part 93 are patterned into predetermined shapes. The first conductive part 91, the second conductive part 92, and the third conductive part 93 are provided on the surface of the insulating layer 94 at a distance from each other sufficient to ensure insulation between them.

[0049] The first conductive portion 91 is electrically connected to the inverter circuit 52. That is, the inverter circuit 52 is provided on the first conductive portion 91. The first conductive portion 91 has a first edge 91a facing the second conductive portion 92. The first conductive portion 91 has a second edge 91b facing the third conductive portion 93.

[0050] The third conductive portion 93 is electrically connected to the connector 48. The third conductive portion 93 has a third end edge 93a that faces the second end edge 91b of the first conductive portion 91. The third conductive portion 93 has a fourth end edge 93b that faces the second conductive portion 92.

[0051] The second conductive portion 92 is electrically connected to each bolt 80 that fixes the circuit board 51 to the first end wall 12a. The second conductive portion 92 has a fifth end edge 92a that faces the first end edge 91a of the first conductive portion 91 and the fourth end edge 93b of the third conductive portion 93.

[0052] The first end of coil 56 is connected to the first conductive part 91. The second end of coil 56 is connected to the third conductive part 93. Therefore, coil 56 electrically connects the first conductive part 91 and the third conductive part 93. Coil 56 electrically connects the first conductive part 91 and the third conductive part 93 while straddling the space between the second end edge 91b of the first conductive part 91 and the third end edge 93a of the third conductive part 93.

[0053] The second conductive part 92 electrically connects the first capacitor group 60 and the second capacitor group 70. The first end of the first capacitor group 60 is connected to the first conductive part 91. The second end of the first capacitor group 60 is connected to the second conductive part 92. The first capacitor group 60 electrically connects the first conductive part 91 and the second conductive part 92. The first capacitor group 60 electrically connects the first conductive part 91 and the second conductive part 92 while straddling the space between the first end edge 91a of the first conductive part 91 and the fifth end edge 92a of the second conductive part 92.

[0054] The first end of the second capacitor group 70 is connected to the third conductive part 93. The second end of the second capacitor group 70 is connected to the second conductive part 92. The second capacitor group 70 electrically connects the third conductive part 93 and the second conductive part 92. The second capacitor group 70 electrically connects the third conductive part 93 and the second conductive part 92 while straddling the space between the fourth end edge 93b of the third conductive part and the fifth end edge 92a of the second conductive part 92.

[0055] Multiple bolts 80 pass through the second conductive portion 92. Each bolt 80 passing through the second conductive portion 92 is electrically connected to the first end wall 12a by being screwed into the first end wall 12a. Therefore, each bolt 80 passing through the second conductive portion 92 functions as a ground. The second conductive portion 92 is then grounded to the vehicle body via each bolt 80 passing through the second conductive portion 92 and the first end wall 12a of the housing 10.

[0056] In the circuit board 51, the switching elements Q1 to Q6 and the coil 56 included in the inverter circuit 52 are major heat sources. Therefore, in this embodiment, as shown in Figure 3, the terminal T for electrically connecting each switching element Q1 to Q6 to the first conductive part 91 is assumed to be the first heat source F1, and the connection point where the terminal T and the first conductive part 91 are electrically connected by soldering or the like is assumed to be the first connection point C1. In this embodiment, the terminal T of the switching element located in the center or approximately in the center among each switching element Q1 to Q6 is assumed to be the first heat source F1. Furthermore, the coil 56 is assumed to be the second heat source F2, and the connection point where the coil 56 and the third conductive part 93 are electrically connected by soldering or the like is assumed to be the second connection point C2.

[0057] Here, as shown in Figure 3, among the bolts 80 that penetrate the second conductive part 92, the bolt closest to terminal T, which is the first heating element F1, is assumed to be the first proximity bolt 81. Similarly, among the bolts 80 that penetrate the second conductive part 92, the bolt closest to coil 56, which is the second heating element F2, is assumed to be the second proximity bolt 82. The first proximity bolt 81 is an example of the "first proximity fastening member" in the present invention. The second proximity bolt 82 is an example of the "second proximity fastening member" in the present invention. Furthermore, a virtual straight line connecting the first connection point C1 and the first proximity bolt 81 is assumed to be the first virtual straight line L1. Similarly, a virtual straight line connecting the second connection point C2 and the second proximity bolt 82 is assumed to be the second virtual straight line L2.

[0058] In this embodiment of the compressor, one of the two first capacitor groups 60 is positioned on the first virtual straight line L1. Similarly, one of the two second capacitor groups 70 is positioned on the second virtual straight line L2.

[0059] Although not shown in Figure 3, the other of the two first capacitor groups 60 is also positioned on another imaginary line connecting the first connection point between the first conductive part 91 and another heat-generating part on the first conductive part 91, and the nearest adjacent bolt among the bolts 80 that penetrate the second conductive part 92. Similarly, although not shown in Figure 3, the other of the two second capacitor groups 70 is also positioned on another imaginary line connecting the second connection point between the third conductive part 93 and another heat-generating part on the third conductive part 93, and the nearest adjacent bolt among the bolts 80 that penetrate the second conductive part 92.

[0060] The two first capacitor groups 60 and the two second capacitor groups 70 all have the same configuration. Therefore, by describing the configuration of one first capacitor group 60 below, a detailed explanation of the configurations of the other capacitor groups will be omitted.

[0061] As shown in Figure 4, the first capacitor group 60 includes two first capacitors 61A and 61B and a pair of first metal frames 62 and 62. Similarly, the second capacitor group 70 includes two second capacitors 71A and 71B and a pair of second metal frames 72 and 72.

[0062] The first capacitors 61A and 61B are so-called multilayer chip-type ceramic capacitors. The first capacitors 61A and 61B have a roughly rectangular parallelepiped shape. External electrodes 61a, 61a are provided at both ends in the longitudinal direction of one of the first capacitors 61A. Similarly, external electrodes 61b, 61b are provided at both ends in the longitudinal direction of the other first capacitor 61B.

[0063] The two first capacitors 61A and 61B are held by a pair of first metal frames 62, 62 with their largest main surfaces facing each other. The two first capacitors 61A and 61B are stacked vertically side by side with their main surfaces facing each other. The lower surface, which serves as the main surface of the upper first capacitor 61A, and the upper surface, which serves as the main surface of the lower first capacitor 61B, face each other.

[0064] Each first metal frame 62 has an L-shaped cross-section. The first metal frame 62 has a connecting portion 62a and a connecting portion 62b that rises from one end of the connecting portion 62a. The connecting portion 62a is electrically connected to the conductive pattern 90. The connecting portion 62b of one first metal frame 62 electrically connects the external electrode 61a on one longitudinal end of the upper first capacitor 61A to the external electrode 61b on one longitudinal end of the lower first capacitor 61B. Similarly, the connecting portion 62b of the other first metal frame 62 electrically connects the external electrode 61a on the other longitudinal end of the upper first capacitor 61A to the external electrode 61b on the other longitudinal end of the lower first capacitor 61B.

[0065] In this compressor configured as described above, the inverter circuit 52 supplies power to the stator 44 and controls the operation of the electric motor 40, causing the electric motor 40 to operate. As a result, the rotor 42 rotates, which activates the compression unit 30 and compresses the refrigerant gas drawn into the motor housing chamber 17. The compressed refrigerant gas is discharged from the discharge port 14a to a condenser (not shown). In this way, air conditioning is performed by the vehicle's air conditioning system.

[0066] Furthermore, noise generated in the inverter circuit 52 mounted on the circuit board 51 flows, for example, through the first capacitor group 60 to the second conductive part 92 and then to ground, or through the coil 56 and the second capacitor group 70 to the second conductive part 92 and then to ground. This prevents noise generated from the inverter circuit 52 from leaking to the outside through the connector 48.

[0067] In this compressor, the first capacitor group 60 connecting the first conductive part 91 and the second conductive part 92 is arranged on a first virtual straight line L1 that connects the first connection point C1 and the first nearest bolt 81 closest to the terminal T, which is the first heat-generating part F1. Therefore, the heat generated at terminal T, which is assumed to be the first heat-generating part F1, is transferred from the first conductive part 91 through the first capacitor group 60 to the second conductive part 92, and then to the first nearest bolt 81. In other words, the heat generated at terminal T, which is the first heat-generating part F1, is transferred to the first nearest bolt 81 through a shorter heat dissipation path compared to when the first capacitor group 60 is not arranged on the first virtual straight line L1. The heat transferred to the first nearest bolt 81 can then be dissipated to the vehicle body through the first end wall 12a of the housing 10. As a result, the heat dissipation efficiency is improved compared to when the first capacitor group 60 is not arranged on the first virtual straight line L1, thus reducing the thermal load on the first capacitor group 60 and making it possible to use capacitors with a narrow operating temperature range, thereby suppressing cost increases. In addition, in the first capacitor group 60, the two first capacitors 61A and 61B are grouped together in one place by the first metal frame 62, so the imbalance in heat dissipation can be suppressed compared to when the two first capacitors are scattered. As a result, the thermal load on the two first capacitors 61A and 61B can be reduced, making it possible to use capacitors with a narrow operating temperature range, thereby suppressing cost increases.

[0068] Similarly, the second capacitor group 70 connecting the third conductive part 93 and the second conductive part 92 is positioned on a second virtual straight line L2 that connects the second connection point C2 and the second nearest bolt 82 closest to the coil 56, which is the second heat-generating part F2. Therefore, the heat generated in the coil 56, which is assumed to be the second heat-generating part F2, is transferred from the third conductive part 93 through the second capacitor group 70 to the second conductive part 92, and then to the second nearest bolt 82. In other words, the heat generated in the coil 56, which is the second heat-generating part F2, is transferred to the second nearest bolt 82 through a shorter heat dissipation path compared to when the second capacitor group 70 is not positioned on the second virtual straight line L2. The heat transferred to the second nearest bolt 82 can then be dissipated to the vehicle body through the first end wall 12a of the housing 10. As a result, the heat dissipation efficiency is improved compared to when the second capacitor group 70 is not arranged on the second virtual line L2, thereby reducing the thermal load on the second capacitor group 70 and making it possible to use capacitors with a narrower operating temperature range, thus suppressing cost increases. In addition, in the second capacitor group 70, the two second capacitors 71A and 71B are grouped together in one place by the second metal frame 72, so the imbalance in heat dissipation can be suppressed compared to when the two second capacitors are scattered. As a result, the thermal load on the two 21st capacitors 71A and 71B can be reduced, making it possible to use capacitors with a narrower operating temperature range, thus suppressing cost increases.

[0069] In this way, the heat generated in the first heat-generating section F1 and the second heat-generating section F2, which are major heat sources on the circuit board 51, can be efficiently dissipated.

[0070] Therefore, according to the compressor of this embodiment, it is possible to improve the heat dissipation efficiency of the circuit board 51 while keeping the cost increase to a minimum.

[0071] Furthermore, in this compressor, the first capacitor group 60 and the second capacitor group 70 allow for increased capacitor capacitance while reducing the mounting area of ​​the capacitors. As a result, the number of components can be reduced and the degree of freedom in component placement can be improved.

[0072] Although the present invention has been described above with reference to examples, it goes without saying that the present invention is not limited to the above examples and can be applied with appropriate modifications without departing from its spirit.

[0073] In the compressor of this embodiment, the number of capacitors in the first capacitor group 60 or the second capacitor group 70 is set to two, but it may be three or more. In the first capacitor group or the second capacitor group 70, multiple capacitors may be arranged horizontally instead of vertically.

[0074] In the compressor of the embodiment, the terminal T of the switching element as a power element in the inverter circuit 52 is designated as the first heat-generating element F1, and the coil 56 is designated as the second heat-generating element F2. However, the present invention is not limited to this, and any heat source on the conductive pattern 90 can be designated as the first heat-generating element F1 or the second heat-generating element F2.

[0075] In the compressor of this embodiment, the conductive pattern has first to third conductive parts 91 to 93, but the number of conductive parts in the conductive pattern is not limited to these, and may be two or four or more. The number of first capacitor group 60 and second capacitor group 70 is also not particularly limited.

[0076] In the compressor of this embodiment, IGBTs are used as the switching elements Q1 to Q6 as power elements, but other semiconductor elements, such as MOSFETs, may be used instead of IGBTs. In this case, diodes D1 to D6 become unnecessary. Also, coil 56 is not limited to a common mode choke coil.

[0077] In the compressor of the embodiment, the compression section 30 is not limited to a scroll type, but may also be a piston type, vane type, or the like.

[0078] The compressor in the embodiment was used in a vehicle air conditioning system, but is not limited to that. For example, the electric compressor of the present invention may be mounted on a fuel cell vehicle and used to compress air, which is supplied as a fluid to the fuel cell, by a compression unit. [Industrial applicability]

[0079] This invention can be used in vehicle air conditioning systems and the like. [Explanation of Symbols]

[0080] 10… Housing 30... Compression section 40…Electric motor 50…Inverter device 51... Circuit board 52…Inverter circuit (electrical circuit) 53…Filter circuit (electrical circuit) 60…First group of capacitors 61A, 61B...First capacitor 62...First metal frame 70...Second group of capacitors 71A, 71B... Second capacitor 72...Second metal frame 80... Bolt (fastening component) 81…First proximity bolt (first proximity fastening member) 82...Second proximity bolt (second proximity fastening member) 90... Conductive pattern 91...First conductive part 92...Second conductive part 93...Third conductive part F1...First heating element F2...Second heat-generating section C1...First connection point C2...Second connection point L1…First virtual line L2…Second virtual line Q1-Q6... Switching elements (power elements) T…Terminal

Claims

1. A compression section that compresses the fluid, An electric motor that drives the compression section, An inverter device that drives the aforementioned electric motor, An electric compressor comprising a compression unit, an electric motor, and a metal housing that accommodates the inverter device, The inverter device is, A circuit board having a conductive pattern including a first conductive portion and a second conductive portion is fixed to the housing by a plurality of metal fastening members, The conductive pattern has an electrical circuit electrically connected to it, The electrical circuit includes a first heating element electrically connected to the first conductive element, The second conductive portion is electrically connected to the housing via the first proximity fastening member, which is the closest to the first heating portion among the plurality of fastening members. The aforementioned electrical circuit includes a filter circuit, The filter circuit has a first group of capacitors that electrically connect the first conductive part and the second conductive part. The first capacitor group comprises a plurality of first capacitors arranged facing each other and having external electrodes at both ends, and a pair of first metal frames that hold the plurality of first capacitors in an electrically connected state. The plurality of first capacitors are held by the pair of first metal frames on the circuit board, stacked vertically with their main surfaces facing each other. Each of the pair of first metal frames has an L-shaped cross-section and includes a connecting portion connected to the conductive pattern and a connecting portion that rises from one end of the connecting portion and electrically connects the external electrodes of each of the first capacitors stacked vertically. The connecting portion of one of the pair of first metal frames is electrically connected to the first conductive portion, and the connecting portion of the other of the pair of first metal frames is electrically connected to the second conductive portion. An electric compressor characterized in that a portion of the first capacitor group is arranged on a first virtual straight line connecting the first connection point between the first heating element and the first conductive element and the first proximity fastening member.

2. The first heating element is a terminal of the power element. The electric compressor according to claim 1, wherein the first virtual straight line connects the first connection point between the terminal and the first conductive part and the first proximity fastening member.

3. The conductive pattern includes a third conductive portion. The electrical circuit includes a second heating element electrically connected to the third conductive part. The second conductive portion is electrically connected to the housing via the second proximity fastening member, which is the closest to the second heating portion among the plurality of fastening members. The filter circuit has a second group of capacitors that electrically connect the third conductive part and the second conductive part. The second capacitor group comprises a plurality of second capacitors arranged facing each other and having external electrodes at both ends, and a pair of second metal frames that hold the plurality of second capacitors in an electrically connected state. The plurality of second capacitors are held by the pair of second metal frames on the circuit board, stacked vertically with their main surfaces facing each other. Each of the pair of second metal frames has an L-shaped cross-section and includes a connecting portion connected to the conductive pattern and a connecting portion that rises from one end of the connecting portion and electrically connects the external electrodes of each of the second capacitors stacked vertically. The connecting portion of one of the pair of second metal frames is electrically connected to the third conductive portion, and the connecting portion of the other of the pair of second metal frames is electrically connected to the second conductive portion. The electric compressor according to claim 1 or 2, wherein a part of the second capacitor group is arranged on a second virtual straight line connecting the second connection point between the second heating element and the third conductive element and the second proximity fastening member.

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