Electric compressor

Abstract

To provide an electric compressor which can suppress an increase of contact resistance.SOLUTION: In an electric compressor, a part of a substrate 31 is supported by a metal element 41 and a power supply busbar 61 electrically connected to the metal element 41 and fixed to a housing. The metal element 41 comprises a terminal part 43 connected to the substrate 31 through a terminal, and a regulation part 46 abutting on the substrate 31. The power supply busbar 61 has a flexible part 63 and elastically energizes the metal terminal 41 toward the substrate 31 via the flexible part 63. Upon thermal deformation, the substrate 31 is supported by the terminal part 43 in a direction away from the power supply busbar 61 and is supported by the terminal part 43 and the regulation part 46 in a direction toward the power supply busbar 61.SELECTED DRAWING: Figure 5

Description

Technical Field

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

Background Art

[0002] For example, Patent Document 1 discloses an electric compressor. The electric compressor disclosed in Patent Document 1 includes a compression part, an electric motor, and an inverter part. The inverter part is housed in an inverter housing. The inverter part includes a circuit board and a power supply bus bar. A circuit bus bar is fixed to the first surface of the circuit board. The circuit bus bar is fixed to the pattern of the circuit board by solder. The end of the power supply bus bar contacts the second surface of the circuit board. The power supply bus bar contacts the pattern of the circuit board.

[0003] A bolt inserted through the circuit bus bar penetrates the circuit board and is inserted into the power supply bus bar. A nut is fastened to the bolt inserted into the power supply bus bar. By this fastening, the circuit bus bar is fastened to the circuit board together with the power supply bus bar, and the power supply bus bar is electrically connected to the pattern of the circuit board.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When a circuit board undergoes repeated thermal expansion and contraction, the difference in the coefficients of thermal expansion between the circuit board and the power supply busbar causes the bolts and nuts connecting the circuit board and the power supply busbar to loosen, increasing contact resistance. To suppress this increase in contact resistance, it is conceivable to electrically connect the power supply busbar to metal terminals with a smaller difference in coefficients of thermal expansion; however, even with this method, suppressing the increase in contact resistance is always desirable. In addition, the circuit board and power supply busbar are sometimes soldered together for electrical connection. However, in this case, repeated thermal expansion and contraction of the circuit board repeatedly generates stress in the solder, increasing contact resistance. [Means for solving the problem]

[0006] The electric compressor for solving the above problems is characterized in that, within the housing space, a portion of the substrate is supported by a metal terminal and a busbar that is electrically connected to the metal terminal and fixed to the housing, the metal terminal comprises a terminal portion that is connected to the substrate and a restricting portion that contacts the substrate, the busbar has a flexible portion that elastically biases the metal terminal toward the substrate by the flexible portion, and the substrate is supported by the terminal portion in the direction away from the busbar and by the terminal portion and the restricting portion in the direction toward the busbar during thermal deformation.

[0007] According to this design, during thermal deformation of the substrate, the substrate is supported by the terminal portion in the direction away from the busbar, and by the terminal portion and the restricting portion in the direction approaching the busbar. This prevents an increase in contact resistance between the substrate and the terminal portion even if thermal expansion and contraction of the substrate occurs repeatedly. Furthermore, the elastic deformation of the busbar due to the bending of the flexible portion causes the metal terminal to be elastically biased toward the substrate. This prevents the busbar and the metal terminal from separating, thus suppressing an increase in contact resistance between the busbar and the metal terminal. In addition, although the metal terminal is elastically biased toward the substrate due to the elastic deformation of the busbar due to the bending of the flexible portion, the restricting portion of the metal terminal contacts the substrate, so the elastic biasing force is supported by the substrate. Therefore, stress generated at the electrical connection point between the terminal portion and the substrate can be suppressed. As a result, an increase in contact resistance can be suppressed.

[0008] In the electric compressor, the busbar comprises a contact portion that contacts the metal terminal, a base portion extending from a defining surface that defines the housing space, and a flexible portion provided between the contact portion and the base portion, and the flexible portion may be bent to include a bent portion formed by bending the busbar.

[0009] According to this, by bending the bent section, the busbar can be easily flexed by the flexible section. With respect to the electric compressor, the busbar may be a power supply busbar that is electrically connected to an external power source located outside the housing.

[0010] According to this, since the electric compressor is separate from the external power supply, the power supply busbar connecting the electric compressor and the external power supply is prone to vibration. Also, a large current flows through the power supply busbar. Even at the point where such a power supply busbar is electrically connected to metal terminals, the increase in contact resistance can be suppressed.

[0011] Regarding the electric compressor, the metal terminal has a busbar contact portion that contacts the busbar, the restricting portion protrudes from the busbar contact portion toward the substrate, the busbar contact portion is thinner than the substrate, and the distance from the busbar contact portion to the tip of the restricting portion is smaller than the distance from the busbar contact portion to the tip of the terminal portion.

[0012] According to this design, the terminal portion can be fixed to the substrate with the tip of the restricting portion in contact with the substrate. This allows the busbar contact portion to be separated from the substrate. Furthermore, because the busbar contact portion is thinner than the substrate and is separated from the substrate, the elastic deformation of the busbar due to the bending of the flexible portion allows the busbar contact portion to be easily bent. As a result of the bending of the busbar contact portion, the busbar contact portion elastically biases the busbar, allowing the busbar contact portion and the busbar to press against each other. This suppresses the increase in contact resistance between the busbar and the metal terminal.

[0013] In the electric compressor, the metal terminal has a busbar contact portion that contacts the busbar, and the metal terminal and the busbar are fastened together by a fastening member. In the busbar contact portion, a widening portion may be provided at the location through which the fastening member is inserted to widen the busbar contact portion.

[0014] According to this, the portion of the busbar contact area through which the fastening member is inserted can be widened by the widening portion. Therefore, the widening portion can reinforce the portion of the busbar contact area through which the fastening member is inserted. [Effects of the Invention]

[0015] This invention can suppress the increase in contact resistance. [Brief explanation of the drawing]

[0016] [Figure 1] Figure 1 is a partially cut cross-sectional view showing an electric compressor according to an embodiment. [Figure 2]FIG. 2 is a partial cross-sectional view showing the inverter section. [Figure 3] FIG. 3 is a partial perspective view showing the inverter section from the power supply bus bar side. [Figure 4] FIG. 4 is a partial plan view showing the inverter section. [Figure 5] FIG. 5 is a partially enlarged view of the power supply bus bar, metal terminal, substrate, and bolt. [Figure 6] FIG. 6 is a perspective view showing the metal terminal. [Figure 7] FIG. 7 is a view showing the power supply bus bar before fixing the substrate to the boss.

Mode for Carrying Out the Invention

[0017] Hereinafter, an embodiment in which an electric compressor is embodied will be described according to FIGS. 1 to 7. <Electric Compressor> As shown in FIG. 1, the electric compressor 10 includes a housing 11, a compression section 15, an electric motor 16, and an inverter section 20. The electric compressor 10 also includes a power supply section 60.

[0018] The housing 11 is made of metal. The housing 11 includes a discharge housing 12, a motor housing 13, and an inverter housing 14. The compression section 15 and the electric motor 16 are housed inside the motor housing 13. The inverter section 20 is housed inside the inverter housing 14.

[0019] The motor housing 13 includes a cylindrical peripheral wall portion 13a and a partition wall portion 13b that closes one end of the peripheral wall portion 13a. The peripheral wall portion 13a and the partition wall portion 13b define a space for housing the compression section 15 and the electric motor 16. The partition wall portion 13b is joined to the inverter housing 14. The peripheral wall portion 13a is provided with a suction port 13c for sucking refrigerant. The discharge housing 12 is joined to the other end of the peripheral wall portion 13a. A discharge port (not shown) is formed in the discharge housing 12. The suction port 13c and the discharge port are connected to an external refrigerant circuit 100.

[0020] As shown in FIGS. 1 and 2, the inverter housing 14 includes a bottom wall portion 14a, an outer wall portion 14b, an inverter cover 14c, and a boss 14d. The bottom wall portion 14a is joined to the partition wall portion 13b of the motor housing 13. The outer wall portion 14b extends from the outer peripheral edge of the bottom wall portion 14a in the thickness direction of the bottom wall portion 14a toward the inverter cover 14c. The outer wall portion 14b is cylindrical. The inverter cover 14c closes the space defined by the bottom wall portion 14a and the outer wall portion 14b. An accommodation space S is defined inside the inverter housing 14. The accommodation space S is defined inside the housing 11. The accommodation space S is defined by the bottom wall portion 14a, the outer wall portion 14b, and the inverter cover 14c. The inverter unit 20 is accommodated in the accommodation space S.

[0021] The bottom wall portion 14a includes a first bottom wall surface 14f and a second bottom wall surface 14g that are opposite to each other in the wall thickness direction of the bottom wall portion 14a. The first bottom wall surface 14f faces the accommodation space S. The first bottom wall surface 14f is a defining surface that defines the accommodation space S. The boss 14d protrudes from the first bottom wall surface 14f of the bottom wall portion 14a toward the inverter cover 14c. The boss 14d protrudes from the first bottom wall surface 14f that defines the accommodation space S inside the housing 11. A female thread is formed on the inner peripheral surface of the boss 14d.

[0022] <Compression portion and electric motor> The electric motor 16 drives the compression portion 15. The electric motor 16 receives three-phase AC power supply from the inverter unit 20 and is driven under the control of the inverter unit 20.

[0023] <Inverter unit> As shown in FIG. 2, the inverter unit 20 includes an inverter circuit 21, a substrate 31, a metal terminal 41, and a fastening member 51.

[0024] The inverter circuit 21 converts DC power into AC power. The electric motor 16 is driven by the AC power output from the inverter circuit 21. As shown in Figures 4 and 5, the substrate 31 has a first mounting surface 31a and a second mounting surface 31b that are opposite to each other in the thickness direction of the substrate 31. The inverter circuit 21 is mounted on the first mounting surface 31a of the substrate 31. A conductor pattern (not shown) is formed on the first mounting surface 31a of the substrate 31, and a conductor pattern 31c is formed on the second mounting surface 31b.

[0025] The substrate 31 has two insertion holes 32, a plurality of terminal insertion holes 33, and fastening holes 34. Each of the two insertion holes 32 penetrates the substrate 31 in the thickness direction. Viewing the substrate 31 in the thickness direction is called a plan view. In the plan view of the substrate 31, each of the two insertion holes 32 is circular in shape. The diameter of the insertion holes 32 is larger than the diameter of the head 51a of the fastening member 51, which will be described later. In the plan view of the substrate 31, the two insertion holes 32 are adjacent to each other. In the plan view of the substrate 31, the direction in which the two insertion holes 32 are aligned is called the first direction X. In the plan view of the substrate 31, the direction perpendicular to the first direction X is called the second direction Y.

[0026] Multiple terminal insertion holes 33 are provided, four around each insertion hole 32. Two terminal insertion holes 33 are provided on each side of one insertion hole 32, sandwiching it in the second direction Y. Each of the multiple terminal insertion holes 33 penetrates the substrate 31 in the thickness direction.

[0027] The fastening holes 34 are formed near the edge of the substrate 31. The position and number of fastening holes 34 may be changed as desired. The metal terminal 41 is formed from a metal material that is more flexible than the power supply bus bar 61. An example of a material used to form the metal terminal 41 is brass.

[0028] As shown in Figures 3, 5, and 6, the metal terminal 41 comprises a busbar contact portion 42, a terminal portion 43, and a restricting portion 46. The busbar contact portion 42 is a thin, rectangular plate. The thickness of the busbar contact portion 42 is thinner than the thickness of the substrate 31. Widening portions 42b are formed on a pair of long edges of the busbar contact portion 42. Each widening portion 42b is located in the center of each long edge of the busbar contact portion 42. The pair of widening portions 42b widen the busbar contact portion 42 in the direction of its short side.

[0029] Through holes 44 are formed in the center of the busbar contact portion 42 in both the long and short directions. The diameter of the through holes 44 is the same as, or slightly different from, the diameter of the through holes 64a. A pair of widening portions 42b sandwich the through holes 44 in the short direction of the busbar contact portion 42. The widening portions 42b are provided in the busbar contact portion 42 where the width is narrowed by the formation of the through holes 44.

[0030] The busbar contact portion 42 comprises a first contact surface 42c and a second contact surface 42d that are opposite to each other in the plate thickness direction. Terminal portions 43 are provided one at each of the four corners of the busbar contact portion 42. Each of the four terminal portions 43 protrudes in a rectangular prism shape from the second contact surface 42d of the busbar contact portion 42. Alternatively, the terminal portions 43 may protrude in a cylindrical shape from the second contact surface 42d of the busbar contact portion 42. The dimension H of the terminal portion 43 is the distance from the second contact surface 42d to the tip of the terminal portion 43. The dimension H of the terminal portion 43 is greater than the thickness of the substrate 31.

[0031] A restricting portion 46 is provided on each of the pair of short edges of the busbar contact portion 42. The restricting portion 46 is sandwiched between two terminal portions 43 at each short edge of the busbar contact portion 42. The restricting portion 46 protrudes in an elongated plate shape from the second contact surface 42d of the busbar contact portion 42. The restricting portion 46 may be formed by one or more protrusions protruding from the second contact surface 42d. The dimension H0 of the restricting portion 46 is the dimension from the second contact surface 42d to the tip of the restricting portion 46. The dimension H0 of the restricting portion 46 is smaller than the dimension H of the terminal portion 43.

[0032] As shown in Figures 3, 4, and 5, each terminal portion 43 of the metal terminal 41 is inserted into the terminal insertion hole 33 of the substrate 31 from the first mounting surface 31a side. Each restricting portion 46 of the metal terminal 41 is in contact with the first mounting surface 31a of the substrate 31. Therefore, even if the metal terminal 41 is elastically biased toward the substrate 31 by the power supply bus bar 61, which will be described later, that elastic biasing force is supported by the substrate 31 via the restricting portion 46. As a result, the metal terminal 41 is pressed against the substrate 31 via the restricting portion 46.

[0033] The terminal portion 43 is joined to the second mounting surface 31b of the substrate 31 by solder 48. Thus, the metal terminal 41 is terminally connected to the substrate 31. Therefore, the metal terminal 41 comprises a terminal portion 43 that is terminally connected to the substrate 31, and a restricting portion 46 that contacts the substrate 31. Furthermore, the terminal connection between the substrate 31 and the terminal portion 43 integrates the substrate 31 and the metal terminal 41, and the substrate 31 is supported by the terminal portion 43 in both the thickness direction. Therefore, even if the substrate 31 undergoes thermal deformation, shrinking or expanding, it remains supported by the terminal connection in both directions: away from and towards the busbar contact portion 42.

[0034] The terminal portion 43 is electrically connected to the conductor pattern 31c of the substrate 31, and the metal terminal 41 is electrically connected to the conductor pattern 31c of the substrate 31. The contact of the restricting portion 46 with the substrate 31 causes the busbar contact portion 42 to be separated from the first mounting surface 31a of the substrate 31. The second contact surface 42d of the busbar contact portion 42 and the first mounting surface 31a of the substrate 31 are separated by the dimension H0 of the restricting portion 46. The dimension H of the terminal portion 43 is greater than the thickness of the substrate 31. Therefore, when the terminal portion 43 is joined to the substrate 31 with solder 48 while the restricting portion 46 is in contact with the first mounting surface 31a, the busbar contact portion 42 separates from the substrate 31.

[0035] <Inverter section and power supply busbar> As shown in Figure 2, the substrate 31 is supported by a boss 14d that protrudes from the first bottom wall surface 14f which defines the housing space S within the housing 11. Substrate fixing bolts 39 that pass through fastening holes 34 are screwed into the boss 14d. The substrate 31 is fixed to the boss 14d by the substrate fixing bolts 39.

[0036] The first mounting surface 31a of the substrate 31 faces the first bottom wall surface 14f. Therefore, the first mounting surface 31a of the substrate 31 is the surface facing the first bottom wall surface 14f on which the boss 14d protrudes, out of the two surfaces of the substrate 31 in the thickness direction.

[0037] The first mounting surface 31a of the substrate 31 is separated from the first bottom wall surface 14f of the bottom wall portion 14a. In the busbar contact portion 42, the second contact surface 42d faces the first mounting surface 31a. The busbar contact portion 42 extends along the first mounting surface 31a, which is the opposing surface described above. Also, the first contact surface 42c of the busbar contact portion 42 is separated from the first bottom wall surface 14f of the bottom wall portion 14a. The first contact surface 42c faces the first bottom wall surface 14f of the bottom wall portion 14a. The restricting portion 46 of the busbar contact portion 42 abuts against the first mounting surface 31a, which is the opposing surface of the substrate 31.

[0038] <Power supply section> The power supply unit 60 is fixed to the bottom wall portion 14a of the inverter housing 14. The power supply unit 60 comprises a pair of power supply busbars 61, a resin portion 68, and a grommet 69.

[0039] As shown in Figures 1, 2, and 3, the power supply busbar 61 extends between the protruding first bottom wall surface 14f of the boss 14d and the busbar contact portion 42. The power supply busbar 61 is a plate-shaped conductive member that supplies power to the electric motor 16. The power supply busbar 61 enables the conduction of large currents. The power supply busbar 61 is electrically connected to a battery B, which is an external power source located outside the housing 11.

[0040] A pair of power supply busbars 61 are held in place by a resin part 68. Insulation between the power supply busbars 61 and the housing 11 is maintained by the resin part 68 and a grommet 69. The grommet 69 is formed of a rubber-based material that surrounds the resin part 68.

[0041] Each of the pair of power supply busbars 61 is made of copper plate. Since the pair of power supply busbars 61 are identical in shape, only one of the power supply busbars 61 will be described. As shown in Figures 3 and 5, the power supply busbar 61 is formed by bending a long, narrow copper plate. The power supply busbar 61 has a first plate surface 61a and a second plate surface 61b that are opposite to each other in the thickness direction. The width direction of the power supply busbar 61 is the direction in which the short sides of the first plate surface 61a and the second plate surface 61b extend. The width W of the power supply busbar 61 is the same at any position in the long side direction. The width W of the power supply busbar 61 is the same as the dimension of the busbar contact portion 42 in the short side direction. Note that the width W of the power supply busbar 61 may be greater than the dimension of the busbar contact portion 42 in the short side direction.

[0042] The power supply busbar 61 comprises a flat base portion 62, an L-shaped flexible portion 63, and a flat contact portion 64. The first end of the base portion 62 is the first end of the power supply bus bar 61. Although not shown, the first end of the base portion 62 is electrically connected to the battery B. The first end side of the base portion 62 is held by the resin portion 68. The second end side of the base portion 62 extends from the grommet 69 toward the substrate 31. The base portion 62 extends from the grommet 69 so as to be perpendicular to the first bottom wall surface 14f. The direction perpendicular to the first bottom wall surface 14f is the wall thickness direction of the bottom wall portion 14a. The first bottom wall surface 14f is a defining surface that defines the housing space S. Therefore, the base portion 62 extends from the defining surface that defines the housing space S.

[0043] A flexible portion 63 extends from the second end of the base portion 62. The flexible portion 63 connects the base portion 62 and the contact portion 64. The flexible portion 63 extends from the base portion 62, and the contact portion 64 extends from the flexible portion 63. The flexible portion 63 comprises a first plate portion 63a that extends intersecting the base portion 62, and a second plate portion 63b that extends intersecting the first plate portion 63a and the contact portion 64. The second plate portion 63b extends from the first plate portion 63a toward the contact portion 64. Each of the first plate portion 63a and the second plate portion 63b is flat.

[0044] The contact portion 64 extends intersecting the second plate portion 63b. The contact portion 64 is flat. When viewed from the first plate surface 61a or the second plate surface 61b, the contact portion 64 is rectangular in shape. The first plate surface 61a in the first plate portion 63a and the first plate surface 61a in the contact portion 64 are opposite each other.

[0045] The contact portion 64 is in contact with the first contact surface 42c of the busbar contact portion 42 on the metal terminal 41. The first contact surface 42c is the surface of the busbar contact portion 42 on the side of the protruding first bottom wall surface 14f of the boss 14d. The second plate surface 61b of the contact portion 64 is in contact with the first contact surface 42c of the busbar contact portion 42 over its entire surface.

[0046] In the power supply bus bar 61, the boundary between the base portion 62 and the flexible portion 63 is a first bend portion 611 where the copper plate bends. In the power supply bus bar 61, the boundary between the first plate portion 63a and the second plate portion 63b in the flexible portion 63 is a second bend portion 612 where the copper plate bends. In the power supply bus bar 61, the boundary between the flexible portion 63 and the contact portion 64 is a third bend portion 613 where the copper plate bends. The flexible portion 63 comprises the first to third bend portions 611 to 613. When the degree of bending of at least one of the first to third bend portions 611 to 613 changes, the flexible portion 63 flexes. Due to the flexing of the flexible portion 63, the power supply bus bar 61 undergoes elastic deformation.

[0047] As described above, the power supply bus bar 61 comprises a contact portion 64 that contacts the metal terminal 41, a base portion 62 extending from the first bottom wall surface 14f, and a flexible portion 63 provided between the contact portion 64 and the base portion 62. The flexible portion 63 is bent to include first to third bent portions 611 to 613 formed by bending the power supply bus bar 61.

[0048] A through hole 64a is formed in the contact portion 64 of the power supply bus bar 61. A female threaded portion 66 is integrally formed on the power supply bus bar 61. The female threaded portion 66 is provided on the first plate surface 61a of the contact portion 64. The female threaded portion 66 is in contact with the contact portion 64. The female threaded portion 66 is formed around the through hole 64a.

[0049] <Fastening member and female thread portion> The fastening member 51 fastens the busbar contact portion 42 of the metal terminal 41 and the contact portion 64 of the power supply busbar 61 together with the female thread portion 66. Therefore, the fastening member 51 fastens the metal terminal 41 and the power supply busbar 61. The fastening member 51 comprises a head portion 51a and a shaft portion 51b. The shaft portion 51b is a male thread. The shaft portion 51b is inserted through the through hole 44 of the busbar contact portion 42 and the through hole 64a of the contact portion 64. The shaft portion 51b that has passed through the through hole 44 and the through hole 64a is screwed into the female thread portion 66. Therefore, the fastening member 51 comprises a shaft portion 51b inserted through the busbar contact portion 42 and the contact portion 64, and a head portion 51a integrated with the shaft portion 51b. The diameter of the head portion 51a is smaller than the diameter of the insertion hole 32 and larger than the diameter of the through hole 44.

[0050] The head 51a of the fastening member 51, which has passed through the insertion hole 32, is in contact with the second contact surface 42d of the busbar contact portion 42. The head 51a and the contact portion 64 sandwich the busbar contact portion 42 of the metal terminal 41. The busbar contact portion 42 and the contact portion 64 are fastened together by tightening the female screw portion 66 and the fastening member 51. In addition, the power supply busbar 61 is electrically connected to the metal terminal 41. Through the electrical connection between the metal terminal 41 and the power supply busbar 61, the battery B and the conductor pattern 31c of the circuit board 31 are electrically connected via the power supply busbar 61 and the metal terminal 41.

[0051] <Operation of the Embodiment> Figure 7 shows the power supply busbar 61 before the substrate 31 is fixed to the boss 14d. The position of the second board surface 61b at the contact portion 64 at this time is defined as the busbar position H1. The busbar position H1 is determined by the distance from the first bottom wall surface 14f to the second board surface 61b.

[0052] The dashed line in Figure 7 shows the position of the metal terminal 41 when the substrate 31 is fixed to the boss 14d. The position of the first contact surface 42c of the busbar contact portion 42 at this time is defined as the metal terminal position H2. The metal terminal position H2 is determined by the distance from the first bottom wall surface 14f to the first contact surface 42c.

[0053] As shown in Figure 7, the busbar position H1 is located closer to the substrate 31 than the metal terminal position H2. In other words, the metal terminal position H2 is located closer to the first bottom wall surface 14f than the busbar position H1.

[0054] When the substrate fixing bolts 39 are screwed into the boss 14d to fix the substrate 31 to the boss 14d, the power supply bus bar 61 is pressed toward the first bottom wall surface 14f by the metal terminals 41. As shown in Figure 5, the first bent portion 611, the second bent portion 612, and the third bent portion 613 of the power supply bus bar 61 bend more than before the substrate 31 was fixed to the boss 14d. When the first to third bent portions 611 to 613 bend, the flexible portion 63 also bends more than before the substrate 31 was fixed to the boss 14d. As a result, the bus bar position H1 is displaced to the metal terminal position H2. In other words, the power supply bus bar 61 undergoes elastic deformation. The power supply bus bar 61 elastically biases the bus bar contact portion 42 toward the substrate 31 due to the restoring force of the flexible portion 63 from its elastically deformed shape back to its original shape. Therefore, the power supply busbar 61 elastically biases the metal terminals 41 toward the substrate 31 by the flexible portion 63.

[0055] The busbar contact portion 42 flexes due to the biasing force applied from the power supply busbar 61, bringing the second contact surface 42d closer to the substrate 31. This flexing causes the busbar contact portion 42 to elastically deform. The busbar contact portion 42 elastically biases the power supply busbar 61 toward the first bottom wall surface 14f due to the restoring force from the elastically deformed shape back to its original shape.

[0056] As a result, the busbar contact portion 42 and the contact portion 64 are in contact with each other in a pressed state. The second plate surface 61b of the contact portion 64 is in contact with the first contact surface 42c of the busbar contact portion 42. The entire surface of the second plate surface 61b of the contact portion 64 is in contact with the first contact surface 42c. From the above, a part of the substrate 31 is supported by the metal terminal 41 and the power supply busbar 61. The power supply busbar 61 is elastically biased by the flexible portion 63 toward the substrate 31, thereby biasing the metal terminal 41 toward the substrate 31.

[0057] According to the above embodiment, the following effects can be obtained. (1) When the substrate 31 undergoes thermal deformation, the substrate 31 is supported by the terminal portion 43 in the direction away from the power supply bus bar 61, and supported by the terminal portion 43 and the restricting portion 46 in the direction approaching the power supply bus bar 61. This prevents the contact resistance between the substrate 31 and the terminal portion 43 from increasing due to repeated thermal expansion and contraction of the substrate 31.

[0058] Furthermore, the elastic deformation of the power supply bus bar 61 due to the bending of the flexible portion 63 causes the metal terminal 41 to be elastically biased toward the substrate 31. This prevents the power supply bus bar 61 and the metal terminal 41 from separating, thus suppressing an increase in contact resistance between the power supply bus bar 61 and the metal terminal 41. In addition, although the metal terminal 41 is elastically biased toward the substrate 31 due to the elastic deformation of the power supply bus bar 61 due to the bending of the flexible portion 63, the restricting portion 46 of the metal terminal 41 contacts the substrate 31, so the elastic biasing force is supported by the substrate 31. Therefore, the stress generated in the solder 48, which is the electrical connection point between the terminal portion 43 and the substrate 31, can be suppressed, thus suppressing an increase in contact resistance in the solder 48. As a result, an increase in contact resistance can be suppressed.

[0059] (2) The busbar contact portion 42 of the metal terminal 41 is thin plate-shaped. In addition, the restricting portion 46 allows the busbar contact portion 42 to be separated from the substrate 31. As a result, the busbar contact portion 42 can bend due to the elastic biasing force from the power supply busbar 61. Due to the bending of the busbar contact portion 42, the busbar contact portion 42 elastically biases the power supply busbar 61, so that the busbar contact portion 42 and the contact portion 64 can be pressed against each other. This prevents the busbar contact portion 42 and the contact portion 64 from separating, and thus prevents the contact resistance between the busbar contact portion 42 and the contact portion 64 from increasing.

[0060] (3) The power supply bus bar 61 is electrically connected to the battery B located outside the housing 11. For this reason, the power supply bus bar 61 is prone to vibration. Also, a large current flows through the power supply bus bar 61. Even at the point where such a power supply bus bar 61 is electrically connected to the metal terminal 41, loosening of the fastening between the fastening member 51 and the female screw portion 66 is unlikely to occur.

[0061] (4) The diameter of the insertion hole 32 is larger than the diameter of the head 51a of the fastening member 51. Therefore, the head 51a can pass through the substrate 31 in the thickness direction. When the busbar contact portion 42 and the contact portion 64 are fastened together, the head 51a does not protrude from the second mounting surface 31b of the substrate 31. Compared to the case where the head 51a protrudes from the second mounting surface 31b of the substrate 31, the inverter unit 20 can be made more compact. In addition, the space between the substrate 31 and the bottom wall portion 14a of the inverter housing 14 can be effectively utilized to further miniaturize the inverter unit 20.

[0062] (5) The widening portion 42b is provided in the busbar contact portion 42 at a position that straddles the through hole 44. The widening portion 42b can widen the area in the busbar contact portion 42 that has become narrowed due to the formation of the through hole 44. Therefore, the widening portion 42b can reinforce the area in the busbar contact portion 42 through which the fastening member 51 is inserted.

[0063] (6) The busbar position H1 before fixing the substrate 31 to the boss 14d is higher than the metal terminal position H2 when the substrate 31 is fixed to the boss 14d. As a result, when the substrate 31 is fixed to the boss 14d, the power supply busbar 61 elastically biases the metal terminal 41 toward the substrate 31. Therefore, since it is not necessary to make the busbar position H1 and the metal terminal position H2 coincide, the inverter unit 20 can be easily fixed to the inverter housing 14.

[0064] (7) The flexible portion 63 elastically deforms the power supply bus bar 61. The flexible portion 63 extends in an L shape between the base portion 62 and the contact portion 64. For example, compared to the case where the flexible portion 63 is bent in a bellows shape, the flexible portion 63 can have a simpler shape.

[0065] <Variation> The embodiment can be implemented with the following modifications. The embodiment and the following modifications can be combined with each other to the extent that they do not contradict the technical principles.

[0066] ○The metal terminal 41 does not need to have a widened portion 42b. ○The restricting portion 46 of the metal terminal 41 is optional. In this case, the busbar contact portion 42 of the metal terminal 41 may have its second contact surface 42d in contact with the first mounting surface 31a of the substrate 31. Even with this configuration, the metal terminal 41 is elastically biased toward the substrate 31 by the power supply busbar 61.

[0067] ○The restricting portion 46 of the metal terminal 41 does not have to protrude from the busbar contact portion 42 toward the substrate 31. In this case, the restricting portion 46 is the portion itself sandwiched between the two terminal portions 43 at each short edge of the busbar contact portion 42.

[0068] ○The busbar may be any busbar other than the power supply busbar 61. For example, the busbar may be a busbar connected to the electric motor 16 in order to supply AC power to drive the electric motor 16.

[0069] ○The flexible portion 63 does not have to be L-shaped, consisting of a first plate portion 63a and a second plate portion 63b. For example, the flexible portion 63 may be curved in an arc shape. Alternatively, the flexible portion 63 may be wave-shaped, having four or more bent portions. The shape of the flexible portion 63 can be arbitrarily changed as long as the bending deformation of the flexible portion 63 can elastically bias the metal terminal 41 toward the substrate 31.

[0070] ○The method of electrically connecting the metal terminal 41 and the power supply busbar 61 does not have to be fastening by fastening member 51 and female screw portion 66. For example, the busbar contact portion 42 and contact portion 64 may be electrically connected by soldering or by welding.

[0071] ○The female thread portion 66 may be a separate nut from the contact portion 64. ○The thickness of the busbar contact portion 42 may be thicker than the thickness of the substrate 31. ○The power supply busbar 61 does not necessarily have to have a contact portion 64. In this case, the tip of the power supply busbar 61 becomes the tip of the flexible portion 63.

[0072] Next, the technical concepts that can be understood from the above embodiments and alternative examples are described below. [Aspect 1] Within the housing space, a portion of the circuit board is supported by metal terminals and busbars that are electrically connected to the metal terminals and fixed to the housing. The metal terminal comprises a terminal portion that is connected to the substrate and a restricting portion that contacts the substrate. The busbar has a flexible portion, and the flexible portion elastically biases the metal terminal toward the substrate. The electric compressor is characterized in that, when the substrate undergoes thermal deformation, it is supported by the terminal portion in a direction away from the busbar, and supported by the terminal portion and the restricting portion in a direction approaching the busbar.

[0073] [Aspect 2] The electric compressor according to [Aspect 1], wherein the busbar comprises a contact portion that contacts the metal terminal, a base portion extending from a defining surface that defines the housing space, and a flexible portion provided between the contact portion and the base portion, and the flexible portion is bent to include a bent portion formed by bending the busbar.

[0074] [Aspect 3] The electric compressor according to [Aspect 1] or [Aspect 2], wherein the busbar is a power supply busbar electrically connected to an external power source located outside the housing.

[0075] [Aspect 4] The metal terminal has a busbar contact portion that contacts the busbar, and the restricting portion protrudes from the busbar contact portion toward the substrate. The electric compressor according to any one of [Aspect 1] to [Aspect 3], wherein the busbar contact portion is thinner than the substrate, and the distance from the busbar contact portion to the tip of the restricting portion in the restricting portion is smaller than the distance from the busbar contact portion to the tip of the terminal portion in the terminal portion.

[0076] [Aspect 5] The electric compressor according to any one of [Aspect 1] to [Aspect 4], wherein the metal terminal has a busbar contact portion that contacts the busbar, the metal terminal and the busbar are fastened together by a fastening member, and the busbar contact portion has a widening portion that widens the busbar contact portion at the location through which the fastening member is inserted. [Explanation of symbols]

[0077] B...Battery as an external power source, S...Housing space, 10...Electric compressor, 11...Housing, 14f...First bottom wall surface as a defining surface, 31...Substrate, 41...Metal terminal, 42...Busbar contact part, 42b...Wide part, 43...Terminal part, 46...Restricting part, 51...Fastening member, 61...Power supply busbar as a busbar, 62...Base, 63...Flexible part, 64...Contact part, 611...First bend part, 612...Second bend part, 613...Third bend part.

Claims

1. Within the housing space, a portion of the circuit board is supported by metal terminals and busbars that are electrically connected to the metal terminals and fixed to the housing. The metal terminal comprises a busbar contact portion that contacts the busbar, a terminal portion that is terminally connected to the substrate, and a restricting portion that abuts against the substrate. The busbar has a flexible portion and a contact portion that contacts the metal terminal, and the flexible portion elastically biases the metal terminal toward the substrate. The busbar contact portion is sandwiched between the fastening member and the contact portion by tightening with the fastening member that fastens the metal terminal and the busbar. The electric compressor is characterized in that, when the substrate undergoes thermal deformation, it is supported by the terminal portion in a direction away from the busbar, and supported by the terminal portion and the restricting portion in a direction approaching the busbar.

2. The electric compressor according to claim 1, wherein the busbar comprises the contact portion, the base portion extending from the defining surface defining the housing space, and the flexible portion provided between the contact portion and the base portion, and the flexible portion is bent to include a bent portion formed by bending the busbar.

3. The electric compressor according to claim 1 or claim 2, wherein the busbar is a power supply busbar electrically connected to an external power source located outside the housing.

4. The restricting portion protrudes from the busbar contact portion toward the substrate, The electric compressor according to claim 1 or 2, wherein the busbar contact portion is thinner than the substrate, and the distance from the busbar contact portion to the tip of the restricting portion in the restricting portion is smaller than the distance from the busbar contact portion to the tip of the terminal portion in the terminal portion.

5. The electric compressor according to claim 1 or claim 2, wherein the busbar contact portion is provided with a widening portion that widens the busbar contact portion at the location through which the fastening member is inserted.

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