Power Conversion Device

Abstract

To provide a power conversion device which suppresses slackness in fixation of a case body and a cover following an environment change.SOLUTION: A power conversion device 10 comprises: an inverter 11; an annular case body 30 which defines a storage space 21; covers 40, 50 which are provided in openings 30A, 30B so as to close the storage space; and a binding band 60 which binds the case body and the cover. The binding band includes: a head part 61 which has a through hole 63 and a fixing part 64; and a band part 62 which has a fixed part 65 that is fixed to the fixing part and is continuous from the head part. The band part is wound in the peripheral direction around the case body and the covers and is inserted to the through hole. The covers and the case body are bound to each other by fixing the fixed part in the peripheral direction to the fixing part.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] TECHNICAL FIELD The disclosure herein relates to power conversion devices. [Background technology]

[0002] Patent Document 1 describes a power converter case that includes a case body and a cover, which are fastened together with screw members. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-187098 Summary of the Invention [Problem to be solved by the invention]

[0004] A screw member is fixed by the engagement of its thread and thread groove. For example, environmental changes such as temperature can cause the connection between the thread and the thread groove to loosen. When the connection between the thread and the thread groove loosens, the screw member rotates in the direction that loosens it, which can loosen the connection between the case body and the cover.

[0005] An object of the present disclosure is to provide a power conversion device in which loosening of the fastening between the case body and the cover due to environmental changes is suppressed. [Means for solving the problem]

[0006] A power conversion device according to one aspect of the present disclosure includes: an inverter (11); a case body (30) having an annular frame that defines a storage space (21) for storing an inverter; a cover (40, 50) provided on the frame opening (30A, 30B) so as to close the storage space; and a binding band (60) for binding the case body and the cover together, The binding band includes a head portion (61) having a through hole (63) and a fixing portion (64), and a band portion (62) extending from the head portion and having a fixed portion (65) fixed to the fixing portion; The band portion is wound around the case body and the cover in the circumferential direction and passed through the through hole, The fixed part is fixed to the fixing part in the circumferential direction, thereby binding the cover and the case body. 、 The fixed portion is hooked onto the fixing portion, and the fixed portion is fixed to the fixing portion in the circumferential direction. The outer dimensions of the cover are larger than those of the case itself. The cover has notches (46, 56) on the edge to regulate the position of the cable tie; The cable tie is passed through the notch. are.

[0007] Because the fixed portion (65) is fixed to the fixing portion (64) in the circumferential direction, even if there is an environmental change, the cable tie (60) is prevented from loosening in the direction in which the band portion (62) comes out of the through hole (63), thereby preventing loosening of the fixation between the case body (30) and the covers (40, 50) due to an environmental change.

[0008] The reference numbers in parentheses above merely indicate the corresponding relationship with the configurations described in the embodiments below, and do not in any way limit the technical scope. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of an in-vehicle system in which a power conversion device is mounted; [Figure 2] FIG. 2 is a top view of the power conversion device as seen from the upper cover side. [Figure 3] FIG. 3 is a cross-sectional view of the power conversion device taken along line III-III. [Figure 4] FIG. 4 is a cross-sectional view of the power conversion device taken along line IV-IV. [Figure 5] FIG. 2 is a top view of the power conversion device as seen from the upper cover side, excluding the cable ties. [Figure 6] FIG. 2 is a top view of the power conversion device as seen from the lower cover side, excluding the cable ties. [Figure 7]FIG. 2 is an enlarged cross-sectional view of the power converter around the bent portion. [Figure 8] FIG. 1 is a schematic diagram of a cable tie. [Figure 9] FIG. 10 is a top view of the power converter of the second embodiment as seen from the upper cover side. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, several embodiments for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, parts corresponding to matters described in the preceding embodiment will be assigned the same reference numerals, and duplicated explanations may be omitted. In each embodiment, when only a part of the configuration is described, the other previously described embodiments may be applied to the other parts of the configuration.

[0011] In addition, it is not only possible to combine parts that are explicitly stated as being possible in each embodiment, but it is also possible to partially combine embodiments, embodiments and variants, and variants even if not explicitly stated, as long as there are no particular problems with the combination.

[0012] (First embodiment) <Power conversion devices and automotive systems> 1 is a schematic diagram of an in-vehicle system 1 equipped with a power conversion device 10. The power conversion device 10 includes an inverter 11, a capacitor 14, and a control circuit board 15. The inverter 11 includes a plurality of semiconductor modules 12. The inverter 11 converts power input from a high-voltage battery 3. The converted power is supplied to a motor generator 6.

[0013] The inverter 11 converts DC power supplied from the high-voltage battery 3 into AC power by turning on and off the semiconductor elements 13 included in the semiconductor module 12. The high-voltage battery 3 is, for example, a plurality of secondary batteries. The secondary batteries may be lithium-ion secondary batteries, nickel-metal hydride secondary batteries, organic radical batteries, or the like.

[0014] The motor generator 6 includes a three-phase AC rotating electric machine, i.e., a three-phase AC motor. The motor generator 6 functions as an electric motor that is a drive source for the vehicle. The motor generator 6 functions as a generator during regeneration. The inverter 11 converts power between the high-voltage battery 3 and the motor generator 6.

[0015] A capacitor 14 is connected to the input side of the inverter 11. A motor generator 6 is connected to the output side of the inverter 11. The capacitor 14 mainly smoothes the DC voltage supplied from the high-voltage battery 3. The capacitor 14 is connected between a high-potential side power line 10A and a low-potential side power line 10B. The high-potential side power line 10A is connected to the high-potential side electrode of the high-voltage battery 3. The low-potential side power line 10B is connected to the low-potential side electrode of the high-voltage battery 3.

[0016] The semiconductor module 12 has two IGBTs and two diodes 13A, which are semiconductor elements 13. The two semiconductor elements 13 are connected in series between a high-potential side power line 10A and a low-potential side power line 10B. A high-potential side input terminal connected to the high-potential side power line 10A is connected to the collector of one of the two semiconductor elements 13, which is provided on the high-potential side. A low-potential side input terminal connected to the low-potential side power line 10B is connected to the emitter of one of the two semiconductor elements 13, which is provided on the low-potential side. A motor terminal connected to the motor-generator 6 is connected to the emitter of the high-potential side semiconductor element 13 and the collector of the low-potential side semiconductor element 13. A control terminal connected to a control circuit board 15 is connected to the gates of the two semiconductor elements 13.

[0017] The anode of the diode 13A is connected to the emitter of the corresponding IGBT. The cathode of the diode 13A is connected to the collector of the corresponding IGBT. The two semiconductor elements 13 and the two diodes 13A are sealed with a resin member. The high-potential input terminal, low-potential input terminal, motor terminal, and control terminal are exposed from the resin member.

[0018] The control circuit mounted on the control circuit board 15 includes a microcomputer. The control circuit board 15 is connected to the low-voltage battery 4. The low-voltage battery 4 supplies power to the control circuit board 15 to operate the microcomputer. The microcomputer includes a CPU, memory, and the like. The control circuit on the control circuit board 15 generates a drive command for operating the IGBT based on a torque request input from a higher-level ECU. The control circuit on the control circuit board 15 outputs, for example, a PWM signal as the drive command.

[0019] <Mechanical configuration of the power conversion device> Next, the mechanical configuration of the power conversion device 10 will be described. In addition to the components described above, the power conversion device 10 includes a case 20, two cable ties 60, a first connector 70, a second connector 80, and a third connector 90. The case 20 includes a case body 30, an upper cover 40, and a lower cover 50. The upper cover 40 and the lower cover 50 may be collectively referred to simply as the covers 40, 50.

[0020] Before explaining the mechanical configuration, the drawings will be described first. FIG. 2 is a top view of the power converter 10 as seen from the upper cover 40 side. FIG. 3 is a cross-sectional view of the power converter 10 taken along line III-III. FIG. 4 is a cross-sectional view of the power converter 10 taken along line IV-IV. FIG. 5 is a top view of the power converter 10 as seen from the upper cover 40 side, excluding the cable ties 60. FIG. 6 is a top view of the power converter 10 as seen from the lower cover 50 side, excluding the cable ties 60. FIG. 7 is a cross-sectional view of the power converter 10 with the bent portion 47 and the surrounding area enlarged. FIG. 8 is a schematic diagram of the cable ties 60. Note that with regard to directions, the thickness direction of the covers 40 and 50 may be referred to as the thickness direction TD. The width direction of the covers 40 and 50 may be referred to as the width direction WD. The depth direction of the covers 40 and 50 may be referred to as the depth direction DP. The thickness direction TD, the width direction WD, and the depth direction DP are three directions that are mutually perpendicular. The direction along the thickness direction TD and the width direction WD may be referred to as the planar direction, which can also be said to be the direction perpendicular to the thickness direction TD.

[0021] <Case> The case 20 forms a single container. The case 20 is made of a metal material. The case 20 comprises a frame-shaped case body 30, a plate-shaped upper cover 40, and a plate-shaped lower cover 50. The case body 30 is made of a metal material whose main component is iron. The covers 40, 50 are made of a metal material whose main component is aluminum. An insulating protective layer 100 is provided on the entire surface of the covers 40, 50, with the exception of a portion. The protective layer 100 has anti-corrosion properties, for example. Note that the protective layer 100 is omitted from the drawings, except in Figure 7.

[0022] The case body 30 extends in the thickness direction TD and has a ring-shaped frame shape centered on an axis along the thickness direction TD. The case body 30 has two ends separated in the thickness direction TD. One end of the case body 30 forms a first opening 30A that opens in the thickness direction TD. Another end of the case body 30 forms a second opening 30B that opens in the thickness direction TD.

[0023] An upper cover 40 is provided at one end of the case body 30 so as to close the first opening 30A. A lower cover 50 is provided at another end of the case body 30 so as to close the second opening 30B. The case body 30, the upper cover 40, and the lower cover 50 define a storage space 21 capable of storing the inverter 11, the capacitor 14, and the control circuit board 15.

[0024] <Case body> The case body 30 has two walls spaced apart in the width direction WD and two walls spaced apart in the depth direction DP. Specifically, the case body 30 includes a first wall portion 31 and a second wall portion 32 spaced apart in the width direction WD, and a third wall portion 33 and a fourth wall portion 34 spaced apart in the depth direction DP. One end of the first wall portion 31 and one end of the second wall portion 32 are connected to the third wall portion 33. The other end of the first wall portion 31 and the other end of the second wall portion 32 are connected to the fourth wall portion 34. Furthermore, no fastening holes into which the bolts 110 are fastened are formed in the walls 31 to 34.

[0025] <Top cover> The upper cover 40 has a flat plate-like shape in the thickness direction TD. The upper cover 40 has an upper outer surface 40A and an upper inner surface 40B that are spaced apart in the thickness direction TD. The upper cover 40 is substantially rectangular when viewed in the thickness direction TD. The upper cover 40 has two edges spaced apart in the width direction WD and two edges spaced apart in the depth direction DP. Specifically, the upper cover 40 has a first upper edge 41 and a second upper edge 42 that are spaced apart in the width direction WD, and a third upper edge 43 and a fourth upper edge 44 that are spaced apart in the depth direction DP. One end of the first upper edge 41 and one end of the second upper edge 42 are connected to the third upper edge 43. The other end of the first upper edge 41 and the other end of the second upper edge 42 are connected to the fourth upper edge 44.

[0026] When viewed in the thickness direction TD, the outer shape of the upper cover 40 is larger than the outer shape of the case body 30. The edge of the upper cover 40 is located outward in the planar direction than the case body 30. The first upper edge portion 41 is located outward in the planar direction than the first wall portion 31. The second upper edge portion 42 is located outward in the planar direction than the first wall portion 31. The third upper edge portion 43 is located outward in the planar direction than the third wall portion 33. The fourth upper edge portion 44 is located outward in the planar direction than the fourth wall portion 34.

[0027] Two notches 45 are also provided on each edge of the upper cover 40. Hereinafter, two notches provided on the same edge may be simply referred to as two notches. The two notches 45 are provided symmetrically across the center of the edge. The distance between the two notches is set to be the same as or slightly larger than the width of the cable tie 60. The two notches 45 are formed continuously from the edge to the wall. The portion of the upper cover 40 between the two notches 45 is bent toward the wall.

[0028] The portions of the upper cover 40 that are bent toward the wall between the two notches 45 may be referred to as bent portions 47 below. It can also be said that the upper cover 40 has bent portions 47 at the center of each edge. It can also be said that the upper cover 40 has two pairs of bent portions 47 arranged at the top, bottom, left, and right. It can also be said that the upper cover 40 has notches 46 formed at the center of each edge when viewed from the thickness direction. It can also be said that the upper cover 40 has two pairs of notches 46 formed at the center of each edge when viewed from the thickness direction. The notches 46 serve to position the cable ties 60 on the edges.

[0029] One bent portion 47 and one notch 46 are provided at the center of the first upper edge portion 41. One bent portion 47 and one notch 46 are provided at the center of the second upper edge portion 42. The bent portion 47 provided at the first upper edge portion 41 and the bent portion 47 provided at the second upper edge portion 42 face each other and overlap in the width direction WD. The notch 46 provided at the first upper edge portion 41 and the notch 46 provided at the second upper edge portion 42 face each other and overlap in the width direction WD.

[0030] Similarly, one bent portion 47 and one notch 46 are provided at the center of the third upper edge portion 43. One bent portion 47 and one notch 46 are provided at the center of the fourth upper edge portion 44. The bent portion 47 provided at the third upper edge portion 43 and the bent portion 47 provided at the fourth upper edge portion 44 face each other and overlap with each other in the depth direction DP. The notch 46 provided at the third upper edge portion 43 and the notch 46 provided at the fourth upper edge portion 44 face each other and overlap with each other in the depth direction DP.

[0031] The four bent portions 47 are bent so as to fit along the walls of the case body 30. The inner radius of the corners of the bent portions 47 is equal to the outer radius of the corners of the walls. The upper inner surfaces 40B inside the bent portions 47 are in contact with the outer surfaces 30C of the wall portions 31 to 34. Since the upper inner surfaces 40B are in contact with the outer surfaces 30C, they are sometimes referred to as contact surfaces. Furthermore, the protective layer 100 is not applied to the upper inner surfaces 40B inside the bent portions 47. This allows electrical continuity between the upper inner surfaces 40B inside the bent portions 47 and the outer surfaces 30C. The case body 30 is grounded by being fastened to the vehicle body with bolts or the like.

[0032] <Lower cover> The lower cover 50 has a flat plate-like shape in the thickness direction TD. The lower cover 50 has a lower outer surface 50A and a lower inner surface 50B that are spaced apart in the thickness direction TD. The lower cover 50 is substantially rectangular when viewed in the thickness direction TD. The lower cover 50 has two edges spaced apart in the width direction WD and two edges spaced apart in the depth direction DP. Specifically, the lower cover 50 has a first lower edge 51 and a second lower edge 52 that are spaced apart in the width direction WD, and a third lower edge 53 and a fourth lower edge 54 that are spaced apart in the depth direction DP. One end of the first lower edge 51 and one end of the second lower edge 52 are connected to the third lower edge 53. The other end of the first lower edge 51 and the other end of the second lower edge 52 are connected to the fourth lower edge 54.

[0033] When viewed in the thickness direction TD, the outer shape of the lower cover 50 is larger than the outer shape of the case body 30. The edge of the lower cover 50 is located further outward in the planar direction than the case body 30. The first lower edge portion 51 is located further outward in the planar direction than the first wall portion 31. The second lower edge portion 52 is located further outward in the planar direction than the first wall portion 31. The third lower edge portion 53 is located further outward in the planar direction than the third wall portion 33. The fourth lower edge portion 54 is located further outward in the planar direction than the fourth wall portion 34.

[0034] The lower cover 50 is also provided with cuts 45, notches 46, and bent portions 47 similar to those on the upper cover 40. Description of these structures and their locations on the lower cover 50 will be omitted in favor of the description of these structures and their locations on the upper cover 40. In the drawings, the cuts formed on the lower cover 50 are indicated as cuts 55 to distinguish them from the cuts 45 formed on the upper cover 40. Similarly, the cuts formed on the lower cover 50 are indicated as cuts 56 to distinguish them from the cuts 46 formed on the upper cover 40. The bent portions formed on the lower cover 50 are indicated as bent portions 57 to distinguish them from the bent portions 47 formed on the upper cover 40. The cuts 56 serve to position the cable ties 60 at the edges.

[0035] The bent portion 57 provided on the first lower edge portion 51 and the bent portion 57 provided on the second lower edge portion 52 overlap and face each other in the width direction WD. The notch 56 provided on the first lower edge portion 51 and the notch 56 provided on the second lower edge portion 52 overlap and face each other in the width direction WD. The bent portion 57 provided on the third lower edge portion 53 and the bent portion 57 provided on the fourth lower edge portion 54 overlap and face each other in the depth direction DP. The notch 56 provided on the third lower edge portion 53 and the notch 56 provided on the fourth lower edge portion 54 overlap and face each other in the depth direction DP.

[0036] The four bent portions 57 are bent so as to fit along the wall of the case body 30. The inner radius of the corners of the bent portions 57 is equal to the outer radius of the corners of the wall. The lower inner surface 50B inside the bent portions 57 is in contact with the outer surface 30C. The lower inner surface 50B is sometimes referred to as the contact surface because it is in contact with the outer surface 30C. Furthermore, the protective layer 100 is not provided on the lower inner surface 50B inside the bent portions 57. This allows electrical continuity between the lower inner surface 50B inside the bent portions 57 and the outer surface 30C. The case body 30 is grounded by being fastened to the vehicle body with bolts or the like.

[0037] <Bundle band> The cable tie 60 has a ring-shaped configuration that surrounds the material to be tied. The cable tie 60 is made of resin, for example. The cable tie 60 is not limited to being made of resin. The cable tie 60 has a structure that allows the diameter of the ring to be adjusted, and has the function of maintaining the adjusted diameter. Figure 8 shows the shape of the cable tie 60 before it surrounds the material to be tied. The cable tie 60 has a head portion 61 and a band portion 62 that continues from the head portion 61.

[0038] The head portion 61 is provided with a through hole 63 for passing the band portion 62 through, and a convex-shaped fixing portion 64 for fixing the band portion 62 after it has passed through. The band portion 62 is provided with a convex-shaped protrusion 65 on one side. Multiple protrusions 65 are provided at predetermined distances along the longitudinal direction of the band portion 62. The protrusions 65 have an undercut shape that prevents them from slipping out in the longitudinal direction. When the band portion 62 is passed through the through hole 63, the undercut portion of the protrusion 65 catches on the fixing portion 64. This fixes the band portion 62 to the fixing portion 64. The fixing portion 64 and the protrusion 65 are engaged and fixed. The fixing portion 64 is sometimes called a hooking portion. The protrusion 65 is sometimes called a fixed portion or a hooking portion.

[0039] Band portion 62 cannot return to its original position in the longitudinal direction, i.e., the circumferential direction of the annular shape, and cannot loosen. This allows cable tie 60 to be maintained at an adjusted diameter. The operator wraps band portion 62 around the material to be tied, and passes band portion 62 through through-hole 63 to reduce the diameter of the annular shape, thereby tightening the material to be tied with cable tie 60.

[0040] In the first embodiment, one cable tie 60 is wound circumferentially around the outer periphery of the case 20, passing through the notch 46 of the first upper edge 41, the notch 46 of the second upper edge 42, the notch 56 of the second lower edge 52, and the notch 56 of the first lower edge 51. More specifically, the band portion 62 of one cable tie 60 passes through these notches 46, 56, is wound around the outer periphery of the case 20 around an axis along the depth direction DP, and is also passed through the through hole 63. The protrusion 65 of the band portion 62 that passed through the through hole 63 is fixed to the fixing portion 64. The case main body 30, the upper cover 40, and the lower cover 50 are tied together around the axis along the depth direction DP by one cable tie 60.

[0041] Furthermore, one cable tie 60 is wound circumferentially around the outer periphery of case 20, passing through notch 46 of third upper edge 43, notch 46 of fourth upper edge 44, notch 56 of fourth lower edge 54, and notch 56 of third lower edge 53. Band portion 62 of another cable tie 60 is wound around the outer periphery of case 20 around an axis along the width direction WD, and is passed through through hole 63. Protrusion 65 of band portion 62 that passed through through hole 63 is fixed to fixing portion 64. One cable tie 60 binds case body 30, upper cover 40, and lower cover 50 together around the axis along the width direction WD.

[0042] The case 20 is bound in a cross shape by two cable ties 60. The case body 30, the upper cover 40, and the lower cover 50 are fastened and bound in a cross shape by the two cable ties 60. The two cable ties 60 press the bent portion 47 of the upper cover 40 and the bent portion 57 of the lower cover 50 against the outer surfaces 30C of the walls 31 to 34 in the planar direction.

[0043] <Connector> As described above, the power conversion device 10 includes the first connector 70, the second connector 80, and the third connector 90. The first connector 70 is a connector that electrically connects the capacitor 14 and the inverter 11 to the high-voltage battery 3. The second connector 80 is a connector that electrically connects the inverter 11 to the motor generator 6. The third connector 90 is a connector that electrically connects the low-voltage battery 4 to the control circuit board 15.

[0044] The first connector 70 and the second connector 80 are provided in a portion of the wall that does not overlap with the cable ties 60. The third connector 90 is provided in a portion of the upper cover 40 that does not overlap with the cable ties 60. The first connector 70 and the second connector 80 may be provided anywhere on the wall as long as they do not overlap with the cable ties 60. The third connector 90 may be provided anywhere on the wall as long as they do not overlap with the cable ties 60.

[0045] <Action and effect> The power conversion device 10 includes an inverter 11, a frame-shaped case body 30, an upper cover 40 and a lower cover 50 that close the opening of the case body 30, and a cable tie 60. A storage space 21 is defined by the case body 30, the upper cover 40, and the lower cover 50. The inverter 11 is provided in the storage space 21. The cable tie 60 is wound around the outer periphery of the case 20 in the circumferential direction.

[0046] The cable tie 60 includes a head portion 61 having a through hole 63 and a fixing portion 64, and a band portion 62 having a protrusion 65. The band portion 62 is passed through the through hole 63. The protrusion 65 of the band portion 62 that has passed through the through hole 63 is then caught on the fixing portion 64, thereby fixing the band portion 62 in place. The cable tie 60 circumferentially ties the case body 30, the upper cover 40, and the lower cover 50 together.

[0047] Because the protrusions 65 are fixed to the fixing portion 64 in the circumferential direction, loosening of the cable tie 60 in the direction in which the band portion 62 comes off the head portion 61 is suppressed even if there is an environmental change. Loosening of the fixation between the case body 30 and the covers 40, 50 due to environmental changes is suppressed. For example, loosening of the fixation between the case body 30 and the covers 40, 50 due to temperature changes is suppressed. Gaps are suppressed from occurring between the case body 30 and the covers 40, 50. Intrusion of moisture, dust, etc. into the case 20 through these gaps is suppressed.

[0048] When viewed in the thickness direction TD, the outer shapes of the covers 40, 50 are larger than the outer shape of the case body 30. The edges of the covers 40, 50 are located further outward than the case body 30 in the planar direction. The covers 40, 50 have notches 46, 56 formed at the center of the edges to position the cable tie 60. The cable tie 60 is passed through the notches 46, 56 and wound circumferentially around the outer periphery of the case 20. Even if there is an environmental change, such as external vibration, the cable tie 60 is prevented from shifting from the desired position. As a result, loosening of the fixation between the case body 30 and the covers 40, 50 is prevented.

[0049] The covers 40, 50 have two pairs of bent portions 47, 57 arranged at top, bottom, left, and right when viewed in the thickness direction. The bent portions 47, 57 are bent to fit along the wall of the case body 30. The upper inner surface 40B on the inside of the bent portion 47 contacts the outer surface 30C. The lower inner surface 50B on the inside of the bent portion 57 contacts the outer surface 30C. Even if there is an environmental change such as external vibration, misalignment between the covers 40, 50 and the case body 30 is suppressed.

[0050] Two pairs of notches 46 are formed in the upper cover 40 and are arranged above, below, left, and right when viewed in the thickness direction. Two pairs of notches 56 are formed in the lower cover 50 and are arranged above, below, left, and right when viewed in the thickness direction. One cable tie 60 is wound in the circumferential direction around the outer periphery of the case 20, passing through the notches 46 in the first upper edge 41, the notches 46 in the second upper edge 42, the notches 56 in the second lower edge 52, and the notches 56 in the first lower edge 51. One cable tie 60 is wound in the circumferential direction around the outer periphery of the case 20, passing through the notches 46 in the third upper edge 43, the notches 46 in the fourth upper edge 44, the notches 56 in the fourth lower edge 54, and the notches 56 in the third lower edge 53.

[0051] Case 20 is bound in a cross shape by two binding bands 60. Case main body 30, upper cover 40, and lower cover 50 are fastened and bound in a cross shape by two binding bands 60. This makes it easier for case main body 30, upper cover 40, and lower cover 50 to be firmly fixed together even if there is an environmental change such as external vibration.

[0052] The case body 30 and covers 40, 50 are made of metal. The inner surfaces 40B, 50B of two pairs of bent portions 47, 57 arranged at the top, bottom, left, and right are in contact with the outer surface 30C of the case body 30, providing electrical continuity. The case body 30 is connected to ground by being fastened to the vehicle body with bolts or the like. Even if radiation noise is emitted from the inverter 11 housed in the storage space 21 during switching, the noise can be dissipated to ground via the case body 30. This prevents radiation noise from leaking outside the case 20.

[0053] The covers 40, 50 are provided with a rust-resistant protective layer 100 except for the upper inner surface 40B of the bent portion 47 and the lower inner surface 50B of the bent portion 57. This allows the case 20 to achieve both rust prevention and suppression of leakage of radiated noise.

[0054] No fastening holes into which bolts 110 are fastened are formed in the wall portions 31 to 34. If fastening holes are formed in the wall portions 31 to 34, the thickness of the wall portions 31 to 34 needs to be the diameter of the fastening holes plus the thickness of the walls that define the fastening holes. Therefore, if fastening holes are formed in the wall portions 31 to 34, the thickness of the wall portions 31 to 34 will be thick. In contrast, since no fastening holes into which bolts 110 are fastened are formed in the wall portions 31 to 34, an increase in the thickness of the wall portions 31 to 34 is suppressed. This leads to a reduction in the physical size of the power conversion device 10.

[0055] (Second embodiment) 9 is a top view of the power conversion device 10 of the second embodiment as seen from the upper cover side. In the second embodiment, in addition to two cable ties 60 arranged so as to overlap each other in a cross shape, bolts 110 are provided at the four corners as seen from the thickness direction TD on the upper cover 40 side. Although not shown, bolts 110 are provided at the four corners as seen from the thickness direction TD on the lower cover 50 side. The case body 30, the upper cover 40, and the lower cover 50 are fixed together by the two cable ties 60 and the bolts 110.

[0056] Naturally, fastening holes for fastening the shanks of corresponding bolts 110 are provided at the end of the case body 30 on the first opening 30A side. Fastening holes for fastening the shanks of corresponding bolts 110 are provided at the end of the case body 30 on the second opening 30B side. By fastening the bolts 110 to the fastening holes provided at the end on the first opening 30A side, the case body 30 and the upper cover 40 are fixed at the four corners when viewed in the thickness direction of the upper cover 40 side. By fastening the bolts 110 to the fastening holes provided at the end on the second opening 30B side, the case body 30 and the lower cover 50 are fixed at the four corners when viewed in the thickness direction of the lower cover 50 side. This more firmly fixes the case body 30, the upper cover 40, and the lower cover 50.

[0057] (Third embodiment) In the embodiments described so far, the cable tie 60 is made of resin. However, the cable tie 60 is not limited to being made of resin. The cable tie 60 may also be made of metal. The cable tie 60 is made of stainless steel, for example. Metal generally has a lower coefficient of thermal expansion than resin. Therefore, in a high-temperature environment, the cable tie 60 itself is more likely to be prevented from stretching. In a high-temperature environment, the cable tie 60 itself stretches, which prevents the gap between the band portion 62 and the case 20 from widening. This prevents loosening of the fixation between the case main body 30 and the covers 40, 50 due to temperature changes.

[0058] (Fourth embodiment) In the embodiments described so far, the case 20 is bound in a cross shape by two binding bands 60. However, the number of binding bands 60 is not limited to two. There may be one binding band 60, or three or more. Furthermore, the arrangement of the binding bands 60 is not limited to a cross. Multiple binding bands 60 may be arranged in parallel. Multiple binding bands 60 may be arranged in a mesh pattern. Even in these cases, it is sufficient that the third connector 90 is provided on the upper cover 40 so as not to overlap the binding bands 60.

[0059] (Fifth embodiment) In the embodiment of the cable tie 60 described above, the head portion 61 is provided with a through hole 63 and a fixing portion 64, and one side of the band portion 62 is provided with a protrusion 65. However, the configuration of the cable tie 60 is not limited to this. The fixing portion 64 may be a buckle lock type. Broadly speaking, the fixing method may be similar to the fixing method used for a wristwatch. For example, the band portion 62 may be provided with a hole instead of the protrusion 65, and the band portion 62 may be fixed to the head portion 61 by passing the fixing portion 64 through the hole.

[0060] (Sixth embodiment) In the embodiments described so far, the case body 30 is frame-shaped, and the openings 30A and 30B are closed by the covers 40 and 50 to define the storage space 21. However, the case body 30 may be box-shaped. As an example, the case body 30 may include a bottom wall and wall portions 31 to 34 standing upright from the bottom wall, and an upper cover 40 may be provided on the first opening 30A, so that the storage space 21 is defined by the case body 30 and the upper cover 40.

[0061] Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and equivalent variations. In addition, although various combinations and configurations are shown in the present disclosure, other combinations and configurations including only one element, more, or less than one element are also within the scope and spirit of the present disclosure. [Explanation of symbols]

[0062] 11 inverter, 110 volts, 15 circuit board, 21 storage space, 30 case body, 30A, 30B openings, 30C outer surface, 4 battery, 40 cover, 40B contact surface, 46 cutout, 47 bending portion, 50 cover, 50B contact surface, 56 cutout, 57 bending portion, 60 cable tie, 61 head portion, 62 band portion, 63 through hole, 64 fixing portion, 65 fixed portion, 90 connector, 100 protective layer.

Claims

1. an inverter (11); a case body (30) having an annular frame that defines a storage space (21) for storing the inverter; a cover (40, 50) provided on the opening (30A, 30B) of the frame so as to close the storage space; a binding band (60) for binding the case body and the cover together, The binding band includes a head portion (61) having a through hole (63) and a fixing portion (64), and a band portion (62) continuing from the head portion and having a fixed portion (65) fixed to the fixing portion, the band portion is wound around the case body and the cover in a circumferential direction and passed through the through hole, The fixed portion is fixed to the fixing portion in the circumferential direction, thereby fastening the cover and the case body together, The fixed portion is hooked onto the fixing portion, and thereby the fixed portion is fixed to the fixing portion in the circumferential direction, The outer shape of the cover is larger than the outer shape of the case body, The cover has notches (46, 56) on its edge to regulate the position of the cable tie; The power conversion device in which the cable tie is passed through the notch.

2. The cutout has at least one pair, The notch is formed by bending a part of the edge, The power converter according to claim 1, wherein a bent portion (47, 57) of the cover that is a bent portion is in contact with the case body.

3. The cutout has two pairs, The cable tie has two of the cable ties, One of the cable ties is passed through a pair of the notches, and another of the cable ties is passed through another pair of the notches, The power conversion device according to claim 2 , wherein the two binding bands overlap each other in a cross shape.

4. The case body and the cover are made of metal, The case body is connected to ground, an insulating protective layer (100) is provided on at least a part of the cover except for a contact surface (40B, 50B) with the case body at the bent portion; The power conversion device according to claim 2 or 3, wherein the contact surface and the outer surface (30C) of the case body are in contact with each other and electrically connected.

5. The battery further includes a connector (90) for connecting the board (15) and the battery (4). The power conversion device according to any one of claims 1 to 3, wherein the connector is provided at a location on the cover that does not overlap with the binding band.

6. The power conversion device according to any one of claims 1 to 3, wherein the case body does not have holes for fastening bolts (110).

7. The power conversion device according to any one of claims 1 to 3, further comprising a bolt (110) for fastening the cover and the case body together.

8. A plurality of the bolts are provided, The power conversion device according to claim 7 , wherein the case body and the cover are fastened together by the bolts at corners of the case body.

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