Electric compressor

Abstract

The heat dissipation performance (cooling performance) of the noise suppression element and the voltage smoothing element is ensured, and the number of components is reduced compared with the prior art. In an electric compressor (1), a target electronic component group (5A), which is a noise suppression element (54a) and a voltage smoothing element (51a), is covered by a block body (8) made of a thermoplastic resin formed in a block shape, said target electronic component group (5A) being mounted on a circuit board (7) of an inverter (5). In this electric compressor (1), a circuit board (7) has one surface (7a) on which an electronic component group (5A) to be mounted is mounted, said surface facing a bottom wall (611) located on the housing (4) side in an inverter housing section (6), and the inverter housing section (6) has a plurality of recesses (651) formed in a portion of the bottom wall (611) facing an end surface (8a) of a block (8). The block (8) has a plurality of protrusions (8b) that protrude from the end surface (8a) toward the bottom wall (611) and that fit into respective recesses (651) that face the block (8) among the plurality of recesses (651).

Description

Technical Field

[0001] The present invention relates to an electric compressor integrally having an inverter. Background Art

[0002] In an electric compressor for compressing a refrigerant in a vehicle air conditioner or the like, most integrally have an inverter that controls power supply to an electric motor (drives the electric motor), and the electric motor converts DC power from an in-vehicle battery or the like into AC power and drives a compression mechanism. Further, a noise suppression element (also referred to as a noise filter) for suppressing noise and a voltage smoothing element (also referred to as a smoothing capacitor) for smoothing the voltage of the DC power input to the inverter are assembled in the circuit of the inverter. An example of such an electric compressor is described in Patent Document 1. In the electric compressor described in Patent Document 1, from the viewpoint of vibration resistance, the entire noise filter and smoothing capacitor are covered with resin.

[0003] Here, the inverter includes a noise suppression element and a voltage smoothing element (noise filter and smoothing capacitor), and it is possible to require suppression of temperature rise due to heat generation for these noise suppression elements and voltage smoothing elements. In this regard, Patent Document 1 discloses that a heat sink member is interposed between the outer wall of an assembly having a noise filter, a smoothing capacitor, and resin covering them and the inner wall of a housing, and heat generated from electronic components in the assembly is dissipated through the heat sink member.

[0004] Patent Document 1: Japanese Patent Laid-Open Publication No. 2013-36394 Summary of the Invention Problems to be Solved by the Invention

[0005] However, in the above structure, it is necessary to dispose a heat sink member between the assembly and the housing, and there is room for improvement from the viewpoints of cost and the like.

[0006] Therefore, an object of the present invention is to provide an electric compressor capable of ensuring heat dissipation (cooling performance) of a noise suppression element and a voltage smoothing element and reducing the number of components compared with the prior art. Means for Solving the Problems

[0007] One aspect of the present invention provides an electric compressor. The electric compressor includes: an electric motor; a compression mechanism that is driven by the electric motor to compress refrigerant; an inverter that includes a target electronic component group and drives the electric motor, the target electronic component group being a noise suppression element and a voltage smoothing element; a housing that houses the compression mechanism and the electric motor; an inverter housing portion that is disposed adjacent to the housing and houses the inverter; and a block that covers the target electronic component group in a posture of being mounted on a circuit board of the inverter and is made of resin formed into a block shape. In this electric compressor, the circuit board has a surface that faces a bottom wall on the housing side in the inverter housing portion and mounts the target electronic component group, the resin is a thermoplastic resin, the inverter housing portion has a plurality of recesses formed in a portion of the bottom wall that faces an end face of the block, and the block has a plurality of protrusions that protrude from the end face toward the bottom wall and are respectively inserted into recesses that face themselves among the plurality of recesses. Advantages of the Invention

[0008] According to the present invention, an electric compressor is provided that can ensure heat dissipation (cooling performance) of the noise suppression element and the voltage smoothing element and can reduce the number of components compared to the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic longitudinal sectional view of the electric compressor according to the embodiment. Figure 2 is a view of the electric compressor according to the embodiment in a state where the cover member of the inverter housing portion is removed and viewed from the side of the inverter housing portion. Figure 3 is a view showing an example of the circuit of the inverter of the electric compressor according to the embodiment. Figure 4 is a view for explaining the state before the target electronic component group in a posture of being mounted on the circuit board is covered by the block. Figure 5 is a view for explaining the state after the target electronic component group is covered by the block. Figure 6 is an exploded perspective view for explaining the internal structure of the inverter housing portion. Figure 7 is a perspective view for explaining the plurality of protrusions on the end face of the block. Figure 8 is Figure 7 a partially enlarged perspective view of Figure 9 is an enlarged top view of the end face of the block. Figure 10It is a diagram for explaining the deformation of the protrusion when the recess is embedded. (a) is a partial cross-sectional view before deformation, and (b) is a partial cross-sectional view after deformation. Detailed implementation mode

[0010] Hereinafter, embodiments of the present invention will be described based on the drawings.

[0011] Figure 1 It is a schematic longitudinal cross-sectional view of an electric compressor 1 according to an embodiment of the present invention. The electric compressor 1 of the embodiment is a so-called inverter-integrated type electric compressor that integrally has an inverter. The electric compressor 1 can be configured to be mounted on a vehicle, for example, and form a part of a refrigerant circuit of a vehicle air conditioner, and compress and discharge refrigerant.

[0012] Refer to Figure 1 , the electric compressor 1 includes: an electric motor 2; a compression mechanism 3 that is driven by the electric motor to compress refrigerant; a housing 4 that houses the electric motor 2 and the compression mechanism 3; an inverter 5 that drives the electric motor 2; and an inverter housing portion 6 that is disposed adjacent to the housing 4 and houses the inverter 5.

[0013] The electric motor 2 is, for example, a three-phase synchronous motor (brushless DC motor). The compression mechanism 3 is, for example, a scroll compression mechanism. The electric motor 2 and the compression mechanism 3 are arranged in series along the axial direction of the output shaft 2a of the electric motor 2 inside the housing 4. The output shaft 2a of the electric motor 2 is connected to the compression mechanism 3 (a rotating scroll member in the case of a scroll compression mechanism).

[0014] The inverter 5 includes various electronic components (described later) and a circuit board 7 on which various electronic components are mounted. In other words, in the present embodiment, various electronic components are mounted on the circuit board 7 to form the inverter 5.

[0015] The inverter housing portion 6 is disposed adjacent to the housing 4. The inverter housing portion 6 is arranged on one end side of the housing 4 in the axial direction. Specifically, it is arranged on the side opposite to the compression mechanism 3 with the electric motor 2 interposed therebetween, and is integrally provided with the housing 4. In the present embodiment, the inverter housing portion 6 includes: a housing main body 61 integrally formed with the housing 4; and a cover member 62 that can be disassembled and assembled relative to the housing main body 61.

[0016] The housing part main body 61 has: a bottom wall 611, located on the side of the housing 4 in the inverter housing part 6; and a peripheral wall 612, rising from the periphery of the bottom wall 611 and defining an opening opposed to the bottom wall 611. The cover member 62 is configured to be mounted on the housing part main body 61 to close the opening. A part of the bottom wall 611 of the housing part main body 61 (which is also the bottom wall of the inverter housing part 6) constitutes a partition wall W that separates the inside of the housing 4 from the inside of the inverter housing part 6. In addition, the power supply line L from the inverter 5 to the electric motor 2 extends through the partition wall W in an airtight and liquid-tight state.

[0017] Figure 2 It is a view of the electric compressor 1 in a state where the cover member 62 of the inverter housing part 6 is removed as viewed from the side of the inverter housing part 6. As Figure 2 shown, the circuit board 7 constituting the inverter 5 is mounted in the inverter housing part 6 (housing part main body 61) by a plurality of board fixing bolts 11 (fixing members).

[0018] Return Figure 1 , a refrigerant inlet 4a is formed at a portion on the side of the partition wall W of the housing 4. The refrigerant flowing into the housing 4 flows in the housing 4 (the gap of the electric motor 2) and reaches the compression mechanism 3. The compression mechanism 3 is driven by the electric motor 2 to compress and discharge the refrigerant. The refrigerant flowing into the housing 4 is, for example, the refrigerant after passing through an expansion valve and an evaporator in the refrigerant circuit of the vehicle air conditioning device and is a low-temperature and low-pressure refrigerant. Therefore, the refrigerant flowing into the housing 4 from the refrigerant inlet 4a can be used to cool the bottom wall 611 including the partition wall W and the electric motor 2. The refrigerant flowing in the housing 4 is compressed by the compression mechanism 3 to become a high-temperature and high-pressure refrigerant and is discharged from the compression mechanism 3. Then, the (high-temperature and high-pressure) refrigerant discharged from the compression mechanism 3 flows out from the refrigerant outlet 4b formed in the housing 4.

[0019] Here, a brief description of the inverter 5 will be given. Figure 3 It is a view showing an example of the circuit structure of the inverter 5. In the present embodiment, the inverter 5 is configured to convert the DC power from an external power source (for example, an in-vehicle battery) VB into three-phase AC power and supply it to the electric motor 2.

[0020] As Figure 3 shown, the inverter 5 includes a voltage smoothing unit 51, a switching unit 52, a control unit (control circuit) 53, and a noise filter 54. And, as described above, they are mounted on the circuit board 7 to constitute the inverter 5.

[0021] The voltage smoothing unit 51 includes a voltage smoothing element 51a, which is a smoothing capacitor. The voltage smoothing unit 51 is connected between the power supply line and the ground line of the external power source VB to smooth the DC power from the external power source VB.

[0022] The switching unit 52 includes six power switching elements Q1 to Q6 and six diodes D1 to D6. Although not particularly limited, the power switching elements Q1 to Q6 may be IGBTs (Insulated Gate Bipolar Transistors). The switching unit 52 is configured to convert the DC power from the external power supply VB smoothed by the voltage smoothing element 51a into three-phase AC power by controlling the power switching elements Q1 to Q6 (PWM control) and supply it to the electric motor 2.

[0023] To further explain the switching unit 52, the switching unit 52 has a U-phase arm, a V-phase arm, and a W-phase arm that are connected in parallel with each other between the power supply line and the ground line of the external power supply VB. Two power switching elements Q1 and Q2 are connected in series in the U-phase arm, and diodes D1 and D2 are reversely connected in parallel to the respective power switching elements Q1 and Q2. Two power switching elements Q3 and Q4 are connected in series in the V-phase arm, and diodes D3 and D4 are reversely connected in parallel to the respective power switching elements Q3 and Q4. Two power switching elements Q5 and Q6 are connected in series in the W-phase arm, and diodes D5 and D6 are reversely connected in parallel to the respective power switching elements Q5 and Q6.

[0024] In addition, the midpoints of the U, V, and W phase arms are connected to the other ends of the U, V, and W phase coils of the electric motor 2 that are star-connected at one end. That is, the midpoint of the power switching elements Q1 and Q2 of the U-phase arm is connected to the U-phase coil, the midpoint of the power switching elements Q3 and Q4 of the V-phase arm is connected to the V-phase coil, and the midpoint of the power switching elements Q5 and Q6 of the W-phase arm is connected to the W-phase coil.

[0025] Moreover, by controlling the ratio of the conduction period of the power switching element on the power supply line side to the conduction period of the power switching element on the ground line side of each phase arm, that is, by performing PWM control on the multiple power switching elements Q1 to Q6, the switching unit 52 can convert the DC power from the external power supply VB smoothed by the voltage smoothing element 51a into three-phase AC power and supply it to the electric motor 2, thereby driving the electric motor 2.

[0026] The control unit 53 controls (PWM control) the power switching elements Q1 to Q6 based on an external signal (for example, a control signal from the control device of the above-mentioned vehicle air conditioning device) to drive the electric motor 2 and then drive the compression mechanism 3.

[0027] The noise filter 54 includes noise suppression elements 54a such as capacitors and coils (inductors) whose illustrations are omitted. Although not particularly limited, in this embodiment, the noise filter 54 is provided between the voltage smoothing unit 51 and the switching unit 52, mainly suppressing ripple noise and EMI / EMC noise caused by the operation of the power switching elements Q1 to Q6.

[0028] Further, the noise suppression element 54a and the voltage smoothing element 51a (hereinafter, appropriately referred to as the target electronic component group 5A) are relatively large-sized and heavy components among the plurality of electronic components constituting the circuit of the inverter 5, and are components that are easily affected by vibration. As described above, the inverter 5 that includes the target electronic component group 5A and drives the electric motor 2 is configured, and the target electronic component group 5A is the noise suppression element 54a and the voltage smoothing element 51a.

[0029] Return Figure 1 , the circuit board 7 has a surface 7a, and the surface 7a faces the bottom wall 611 on the housing 4 side in the inverter housing portion 6 (housing portion main body 61). Further, the target electronic component group 5A is mounted on one surface 7a of the two surfaces of the circuit board 7 that faces the bottom wall 611. That is, the circuit board 7 has a surface 7a (in other words, the surface on the partition wall side of the circuit board 7), the surface 7a faces the bottom wall 611 of the inverter housing portion 6, and the target electronic component group 5A is mounted thereon.

[0030] Although not particularly limited, in the present embodiment, among the electronic components constituting the inverter 5, the power switch elements Q1 to Q6 constituting the switching unit 52 and the electronic components of the control unit 53 are mounted on one surface 7a of the circuit board 7 in the same manner as the target electronic component group 5A. That is, in the present embodiment, the electronic components constituting the switching unit 52 and the control unit 53 are mounted on the circuit board 7 together with the target electronic component group 5A.

[0031] Here, referring to Figure 1 , the electric compressor 1 includes a block 8 that covers the target electronic component group 5A, which is the noise suppression element 54a and the voltage smoothing element 51a. As Figure 1 shown, the block 8 is a member made of resin formed in a block shape that covers the target electronic component group 5A in a posture of being mounted on the circuit board 7 of the inverter 5. That is, in a state where the target electronic component group 5A is electrically connected to and mounted on the circuit board 7, the block 8 is resin-molded so as to cover the periphery of the target electronic component group 5A and is integrated with the circuit board 7.

[0032] The resin for the block 8 is a thermoplastic resin, for example, a thermoplastic elastomer such as a thermoplastic polyurethane elastomer, a thermoplastic polyester elastomer, or a thermoplastic polyamide elastomer, which has elasticity close to that of rubber and good moldability comparable to that of plastics. In the case of these resins, the resin injection pressure during molding is lower than that in the case of general injection molding and is higher than atmospheric pressure. Therefore, the load on the electronic components during molding is reduced compared to the case of injection molding. In addition, the shape of the block 8 will be described in detail later.

[0033] Figure 4 is a diagram for explaining the state before the target electronic component group 5A in the posture of being mounted on the circuit board 7 is covered by the block body 8. Figure 5 is a diagram for explaining the state after the target electronic component group 5A is covered by the block body 8. As Figure 4 shown, the target electronic component group 5A (the noise suppression element 54a and the voltage smoothing element 51a) is mounted in a manner concentrated in a specified area on one surface 7a of the circuit board 7. And, the block body 8 is integrated with the circuit board 7 by covering the target electronic component group 5A in the posture of being mounted on one surface 7a of the circuit board 7, as Figure 5 shown.

[0034] Next, the housing structure of the inverter 5 in the present embodiment will be described. As described above, in the present embodiment, the inverter 5 is housed in the inverter housing portion 6.

[0035] Figure 6 is an exploded perspective view for explaining the internal structure of the inverter housing portion 6. As described above, the inverter housing portion 6 includes a housing portion main body 61 and a cover member 62. In addition, in the present embodiment, the inverter housing portion 6 has a first setting portion 63 for setting the power switching elements Q1 to Q6, a substrate support portion 64 for supporting the circuit board 7, and a second setting portion 65 for setting the block body 8 inside. Also, since Figure 1 is a schematic cross-sectional view, the shape of the inner bottom surface of the housing portion main body 61 shown in Figure 1 is not strictly the same as the shape of the inner bottom surface of the housing portion main body 61 shown in Figure 6 shown.

[0036] The first setting portion 63 is set on the inner bottom surface of the housing portion main body 61. Specifically, it is set on the surface on the inverter housing portion 6 side of the partition wall W which is a part of the bottom wall 611, and is formed as a flat surface. In the present embodiment, the power switching elements Q1 to Q6 are arranged in two columns. That is, the power switching elements Q1, Q3, and Q5 are arranged on one side, and the power switching elements Q2, Q4, and Q6 are arranged on the other side. Threaded holes 631 are formed near the first setting portion 63, and the element fixing bolts 12 which are fixing members for fixing the power switching elements Q1 to Q6 are screwed into the threaded holes 631.

[0037] The substrate support portion 64 is configured to support the circuit board 7 at a position farther from the first setting portion 63 than the partition wall W (the surface on the inverter accommodation portion 6 side). That is, within the inverter accommodation portion 6, the circuit board 7 is disposed at a position closer to the cover member 62 than the power switching elements Q1 to Q6. In the present embodiment, the substrate support portion 64 includes a plurality of legs 641 that respectively project from the inner bottom surface of the accommodation portion main body 61, that is, the surface on the inverter accommodation portion 6 side of the partition wall W, and threaded holes that are screwed with the above-described substrate fixing bolts 11 (refer to Figure 2 ) are formed on the upper surfaces of the plurality of legs 641.

[0038] The second setting portion 65 is set on the inner bottom surface of the accommodation portion main body 61. Specifically, it is set on the surface of the bottom wall 611 that faces the end surface 8a of the block 8. Most of the surface of the second setting portion 65 is formed as a flat surface, and a part of the second setting portion 65 protrudes toward the cover member 62 side. And a plurality of recesses 651 are formed in the second setting portion 65. That is, the inverter accommodation portion 6 has a plurality of recesses 651 that are formed in the part of the bottom wall 611 that faces the end surface 8a of the block 8.

[0039] The plurality of recesses 651 are arranged at intervals and are formed as bottomed holes of the same shape. In the present embodiment, the plurality of recesses 651 are respectively formed as straight circular holes.

[0040] Refer to Figure 6 , the power switching elements Q1 to Q6 each have three terminals c1. In the present embodiment, the three terminals c1 extend laterally from one side surface of the power switching element and bend midway so that the front ends face upward. In the present embodiment, in a state where the power switching elements Q1 to Q6 are placed on the first setting portion 63 of the inverter accommodation portion 6 via the insulating sheet 41, they are fixed to the first setting portion 63 via two element fixing bolts 12 and the plate 66.

[0041] Specifically, the insulating sheet 41 is formed of a material having heat dissipation and insulation properties and has a size capable of covering the entire lower surface of the power switching elements Q1 to Q6. And the insulating sheet 41 is sandwiched between the lower surface of the power switching elements Q1 to Q6 and the first setting portion 63. And the power switching elements Q1 to Q6 are sandwiched between the plate 66 and the insulating sheet 41 for each column. The portion where the threaded holes 631 for the element fixing bolts 12 are formed protrudes toward the cover member 62 side, and the base end of the plate 66 is fixed to the portion where the threaded holes 631 are formed via the element fixing bolts 12. As a result, the power switching elements Q1, Q3, and Q5 and the power switching elements Q2, Q4, and Q6 are respectively pressed and fixed to the first setting portion 63 by the element fixing bolts 12 and the plate 66.

[0042] Next, the shape of the block 8 will be described.Figure 7 is a three-dimensional diagram for explaining the shape of the block 8. Figure 8 yes Figure 7 A partial enlarged stereogram of Figure 9 It is an enlarged top view of the end surface 8 a of the block 8 .

[0043] Reference Figure 1 The block 8 not only covers the surfaces of the plurality of electronic components (the noise suppression element 54 a and the voltage smoothing element 51 a ), but is also formed in a block shape so as to fill spaces between the plurality of electronic components.

[0044] And, refer to Figure 7 and Figure 8 The block 8 has a plurality of protrusions 8b, which protrude from the end face 8a of the block 8 toward the bottom wall 611 of the inverter storage section 6 (storage section main body 61), and are respectively embedded in the recesses 651 opposite to themselves among the plurality of recesses 651 of the inverter storage section 6 (second setting section 65). That is, the plurality of protrusions 8b are formed in a one-to-one relationship with the plurality of recesses 651 and in a cross-sectional shape that can be interlocked with each other. The number of protrusions 8b is consistent with the number of recesses 651. Here, since the protrusion 8b is a part of the block 8 made of thermoplastic resin, the protrusion 8b also has thermoplasticity. However, the protrusion 8b has heat resistance and can maintain the interlocking state with the recess 651 within the range of temperature rise caused by the heat generation of the noise suppression element 54a and the voltage smoothing element 51a.

[0045] Although not particularly limited, in this embodiment, the plurality of recesses 651 are each formed as a straight circular hole as described above, and the plurality of protrusions 8b each have a conical cone-shaped outer surface with a tapered tip. That is, the hole diameter of each recess 651 is fixed and does not change in the depth direction, and the interior of each recess 651 is formed as a cylindrical space extending in a straight line. Furthermore, each protrusion 8b is formed as a whole into a generally tapered pin-shaped outer shape with a slightly tapered tip, and the tapered angle is set to the draft angle during molding or an angle slightly larger than it.

[0046] Reference Figure 9 In this embodiment, each of the plurality of protrusions 8b has a deformation-allowing groove 8c that allows deformation of the protrusion in a direction intersecting the protruding direction. Although not particularly limited, the deformation-allowing groove 8c is formed as a groove having mutually orthogonal X-shaped grooves 8c1 and a cylindrical groove 8c2 extending along the central axis of the protrusion 8b and passing through the intersection of the X-shaped grooves 8c1, for example, when viewed from above toward the end surface 8a of the block 8.

[0047] Figure 10 1 and 12 are diagrams for explaining deformation of the protrusion 8b when the protrusion 8b is fitted into the recess 651, wherein (a) is a partial cross-sectional view before deformation and (b) is a partial cross-sectional view after deformation.Figure 10 In (a), the outer dimension of the protrusion 8b is set to be slightly larger than the hole diameter of the recess 651. And when the front end corner of the protrusion 8b abuts against the opening corner of the recess 651, the protrusion 8b elastically deforms in a direction crossing the protruding direction, specifically, in the direction toward the central axis of the protrusion 8b (in other words, in the direction toward the radially inner side of the recess 651), in such a manner that the diameter gradually decreases from the front end side. And as Figure 10 shown in (b), the protrusion 8b is inserted into the recess 651 until near its base end and is held in the recess 651. This insertion is performed by each protrusion 8b. As a result, the block 8 covering the noise suppression element 54a and the voltage smoothing element 51a in the posture of being mounted on the circuit board 7 is positioned and held at a prescribed position (the second setting portion 65) in the inverter housing portion 6 by the engagement of the plurality of protrusions 8b and the plurality of recesses 651.

[0048] In the present embodiment, the object electronic component group 5A and the sleeve member 9 are covered by the block 8, and the board fixing bolt 11 for fixing the circuit board 7 to the inverter housing portion 6 penetrates through the sleeve member 9. The sleeve member 9 is arranged at a plurality of places (three places in the figure) around the object electronic component group 5A in the circuit board 7. The sleeve member 9 is, for example, a metallic cylindrical member. The sleeve member 9 is integrally formed with the block 8 at the position of the outer edge portion in the block 8 and on the end face closer to the circuit board 7 side. And referring to Figure 1 , one end of the sleeve member 9 abuts against one surface 7a of the circuit board 7, and the other end of the sleeve member 9 abuts against the upper surface of a prescribed leg portion 641 among the plurality of leg portions 641 of the board support portion 64 around the second setting portion 65.

[0049] Next, the installation of the circuit board 7 to the board support portion 64 will be described. In the present embodiment, the circuit board 7 is installed to the board support portion 64 after the plurality of power switch elements Q1 to Q6 are provided (fixed) in the first setting portion 63.

[0050] In the present embodiment, other electronic components among the electronic components constituting the inverter 5 are pre-installed on the circuit board 7, other than the power switch elements Q1 to Q6. Specifically, in the present embodiment, on one surface 7a of the circuit board 7 facing the bottom wall 611 of the housing main body 61 (the surface facing the partition wall W when the circuit board 7 is installed to the board support portion 64), the electronic components constituting the object electronic component group 5A (the noise suppression element 54a and the voltage smoothing element 51a), the diodes D1 to D6, and the control portion 53 are pre-installed (electrically connected and installed). However, the diodes D1 to D6 are omitted in Figures 4 to 6 .

[0051] Further, the object electronic component group 5A in a posture of being mounted on one surface 7a of the circuit board 7 is covered by the block body 8 together with a plurality of (three in the figure) sleeve members 9 and integrated with the circuit board 7.

[0052] In addition, terminal holes 71 for connecting (inserting) the respective terminals c1 of the power switching elements Q1 to Q6 are formed in the circuit board 7. Further, a plurality of insertion holes 72 through which the board fixing bolts 11 can be inserted are respectively formed in the circuit board 7. The plurality of insertion holes 72 are arranged corresponding to the plurality of leg portions 641 constituting the board support portion 64.

[0053] And the circuit board 7 is placed on the board support portion 64 (that is, the upper surfaces of the plurality of leg portions 641) of the inverter storage portion 6 with one surface 7a as the lower side. At this time, the respective protrusion portions 8b of the end surface 8a of the block body 8 are elastically deformed and inserted into the corresponding concave portions 651 of the inverter storage portion 6. In the present embodiment, the height of the noise suppression element 54a from the circuit board 7 is lower than the height of the voltage smoothing element 51a from the circuit board 7. Therefore, the height of the portion of the end surface 8a of the block body 8 covering the noise suppression element 54a from the circuit board 7 is lower than the height of the portion of the end surface 8a of the block body 8 covering the voltage smoothing element 51a from the circuit board 7. And according to the difference in the height of the end surface 8a of the block body 8, the height position of the surface of the formed portion of the concave portion 651 of the second setting portion 65 of the inverter storage portion 6 is different. That is, the surface of the formed portion of the concave portion 651 corresponding to the noise suppression element 54a in the second setting portion 65 is located on the side closer to the cover member 62 than the surface of the formed portion of the concave portion 651 corresponding to the voltage smoothing element 51a in the second setting portion 65. That is, in the present embodiment, a step is provided in the second setting portion 65 where the block body 8 is provided.

[0054] Further, the plurality of insertion holes 72 of the circuit board 7 are arranged on the threaded holes formed on the upper surfaces of the plurality of leg portions 641, and the respective terminals c1 of the power switching elements Q1 to Q6 are inserted into the terminal holes 71 of the circuit board 7, and the front ends protrude from the other surface (the surface opposite to the surface on the partition wall side) of the circuit board 7.

[0055] Thereafter, the circuit board 7 placed on the substrate support portion 64 (the upper surfaces of the plurality of leg portions 641) is fixed to the substrate support portion 64 by a plurality of substrate fixing bolts 11. Specifically, the circuit board 7 is fixed to the substrate support portion 64 by screwing the plurality of substrate fixing bolts 11 inserted into the plurality of insertion holes 72 with the threaded holes formed on the upper surfaces of the plurality of leg portions 641. At this time, several (three in the figure) of the substrate fixing bolts 11 around the block 8 among the plurality of substrate fixing bolts 11 respectively pass through the sleeve members 9 integrated with the block 8, and the block 8 is also fastened together with the substrate support portion 64 by the substrate fixing bolts 11. In addition, by welding the front end portions of the respective terminals c1 of the power switching elements Q1 to Q6 to the circuit board 7, the power switching elements Q1 to Q6 are electrically connected to the circuit board 7. Through the above steps, the circuit board 7 is mounted on the substrate support portion 64. Thereafter, the inverter 5 is housed in the inverter housing portion 6 by mounting the cover member 62 to the housing portion main body 61 via fastening bolts (not shown).

[0056] In the present embodiment, a gap is provided between a portion (second setting portion 65) of the bottom wall 611 of the inverter housing portion 6 that faces the end face 8a of the block 8 and the end face 8a of the block 8. That is, in a state where the protrusion 8b is elastically deformed and fitted into the recess 651, the end face 8a of the block 8 does not contact the second setting portion 65.

[0057] In the present embodiment, the circuit board 7 is configured to be detachable from and attachable to the inverter housing portion 6 via the plurality of substrate fixing bolts 11 and the substrate support portion 64. In addition, auxiliary holes 73 for loosening the bolts are formed in portions of the circuit board 7 corresponding to the element fixing bolts 12. When the circuit board 7 is removed, the element fixing bolts 12 are loosened by a tool inserted through the auxiliary holes 73, and the pressing of the element fixing bolts 12 and the plate 66 against the power switching elements Q1 to Q6 is released. As a result, the circuit board 7 is removed together with the respective electronic components and the block 8 constituting the inverter 5.

[0058] According to the electric compressor 1 of the present embodiment, the following effects can be obtained.

[0059] The object electronic component group 5A in a posture of being mounted on the circuit board 7 of the inverter 5 is covered by a block 8 made of a thermoplastic resin formed in a block shape. The object electronic component group 5A is a noise suppression element 54a and a voltage smoothing element 51a. The circuit board 7 has a surface 7a that faces the bottom wall 611 on the housing 4 side in the inverter housing portion 6 and on which the object electronic component group 5A is mounted. The inverter housing portion 6 has a plurality of recesses 651 formed in a portion of the bottom wall 611 that faces the end surface 8a of the block 8. The block 8 has a plurality of protrusions 8b that protrude from the end surface 8a toward the bottom wall 611 and are respectively inserted into the recesses 651 that face themselves among the plurality of recesses 651. Therefore, without separately providing a heat sink member, the heat generated from the object electronic component group 5A (noise suppression element 54a and voltage smoothing element 51a) is effectively dissipated to the housing 4 side through the inner walls of the plurality of recesses 651 with a large heat transfer area from the plurality of protrusions 8b of the block 8 itself. In this way, the electric compressor 1 can ensure the heat dissipation (cooling property) of the noise suppression element and the voltage smoothing element, and can reduce the number of components compared with the prior art, and further can achieve a low manufacturing cost.

[0060] In addition, since the block 8 is formed of a thermoplastic resin, even if the manufacturing tolerances of the dimensions of the protrusions 8b and the recesses 651 are large, the fitting of the protrusions 8b and the recesses 651 is established by the elastic deformation of the protrusions 8b, and the assembly workability can be improved. As in the present embodiment, even when a step is provided in the second setting portion 65 where the block 8 is provided, the block 8 can be stably set without using a gasket or a thin sheet material for fine adjustment of the height of the setting surface by the elastic deformation of the protrusions 8b. In addition, by using the elasticity of the thermoplastic resin, the generation of the resilience force on the electronic components during fitting can be suppressed, and the load on the electronic components can be reduced.

[0061] In the present embodiment, each of the plurality of protrusions has a deformation allowance groove 8c that allows the deformation of itself in a direction crossing the protruding direction. Thus, since the protrusions 8b are more easily elastically deformed, the positioning of the block 8 during assembly becomes easy, and the assembly workability can be further improved.

[0062] In the present embodiment, the object electronic component group 5A and the sleeve member 9 are covered by the block 8 together, and the substrate fixing bolt 11 that fixes the circuit board 7 to the inverter housing portion 6 penetrates through the sleeve member 9. Thus, the vibration resistance of the object electronic component group 5A is improved.

[0063] In the present embodiment, the electronic components constituting the switch portion 52 and the control portion 53 are mounted on the circuit board 7 together with the object electronic component group 5A, and the circuit board 7 is configured to be detachable from the inverter housing portion 6. Thus, the number of components of the inverter 5 is reduced, miniaturization is achieved, and the assemblability is improved.

[0064] In the present embodiment, a gap is provided between a portion of the bottom wall 611 of the inverter housing portion 6 that faces the end face 8a of the block 8 and the end face 8a of the block 8. Thereby, the resin usage amount of the block 8 itself can be suppressed.

[0065] In addition, the end face 8a of the block 8 may be in contact with the bottom wall 611. Further, the shape of the deformation allowance groove 8c of the protrusion 8b is not limited to an X shape, and may be an I shape or the like. Further, the deformation allowance groove 8c may not be provided. And, as long as the protrusion 8b and the recess 651 can be engaged, the shapes and the number of the protrusion 8b and the recess 651 can be arbitrarily set.

[0066] As described above, the embodiments and the modified examples of the present invention have been described, but the present invention is not limited to the above-described embodiments and modified examples, and of course, further modifications can be made based on the technical idea of the present invention. Description of reference numerals:

[0067] 1: Electric compressor; 2: Electric motor; 3: Compression mechanism; 4: Housing; 5: Inverter; 5A: Target electronic component group; 51a: Voltage smoothing element; 54a: Noise suppression element; 6: Inverter housing portion; 7: Circuit board; 7a: One surface; 8: Block; 8a: End face; 8b: Multiple protrusions; 8c: Deformation allowance groove; 9: Sleeve member; 11: Substrate fixing bolt; 52: Switching portion; 53: Control portion; 611: Bottom wall; 651: Multiple recesses; Q1 to Q6: Power switch elements.

Claims

1. An electric compressor, wherein, Comprising: An electric motor; A compression mechanism driven by the electric motor to compress a refrigerant; An inverter including a target electronic component group and driving the electric motor, the target electronic component group being a noise suppression element and a voltage smoothing element; A housing accommodating the compression mechanism and the electric motor; An inverter accommodation portion disposed adjacent to the housing and accommodating the inverter; And A block covering the target electronic component group in a posture of being mounted on a circuit board of the inverter and made of resin formed in a block shape, The circuit board has a surface that faces a bottom wall on the housing side in the inverter accommodation portion and mounts the target electronic component group, The resin is a thermoplastic resin, The inverter accommodation portion has a plurality of recesses formed in a portion of the bottom wall facing an end face of the block, The block has a plurality of protrusions protruding from the end face toward the bottom wall and respectively inserted into the recesses facing themselves among the plurality of recesses.

2. The electric compressor according to claim 1, wherein Each of the plurality of protrusions has a deformation allowance groove allowing deformation of itself in a direction crossing the protruding direction.

3. The electric compressor according to claim 1, wherein The target electronic component group is covered by the block together with a sleeve member, and a circuit board fixing bolt for fixing the circuit board to the inverter accommodation portion penetrates through the sleeve member.

4. The electric compressor according to claim 1, wherein The inverter includes a switch portion having a plurality of power switch elements and a control portion for controlling the plurality of power switch elements based on an external signal, Electronic components constituting the switch portion and the control portion are mounted on the circuit board together with the target electronic component group, The circuit board is configured to be detachable from the inverter accommodation portion.

5. The electric compressor according to any one of claims 1 to 4, wherein A gap is provided between a portion of the bottom wall of the inverter accommodation portion facing the end face of the block and the end face of the block.

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