Circuit unit

Abstract

The present invention discloses a circuit unit that can suppress gap deviation caused by the tolerance between the thermal contact part of the heat-generating component housed in the housing and the heat dissipation object, thereby improving heat dissipation performance. The circuit unit (10) includes: a heating element (22) having a heat contact portion (14) that is in thermal contact with a heat dissipation object (12) and a fixing portion (16) that is fixed to the heat dissipation object (12); a housing (24) for holding the heating element (22); a holding portion (26) protruding from the interior of the housing (24) for holding the heating element (22) inside the housing (24); an opening window (28) through the housing (24) for exposing the heat contact portion (14) of the heating element (22) to the outside of the housing (24); and an insertion hole (30) through the housing (24) for inserting the fixing portion (42) provided on the heat dissipation object (12). By fixing the fixing portion (16) of the heating element (22) to the fixing portion (42) inserted into the insertion hole (30), the heating element (22) is separated from the holding portion (26), and the heat contact portion (14) of the heating element (22) is in thermal contact with the heat dissipation object (12).

Description

Technical Field

[0001] This disclosure relates to circuit units. Background Technology

[0002] Patent Document 1 discloses a circuit unit housed within a battery pack mounted in a vehicle, which switches between energized and de-energized states between the battery and a load. Within the circuit unit, heat-generating components such as a relay and a pre-charge resistor (acting as a ceramic resistor) are housed within a casing. To facilitate heat dissipation from these heat-generating components, the circuit unit in Patent Document 1 employs a structure where the thermal contact portion of the heat-generating component, fixed to the casing, contacts the outer metal casing (which is the object of heat dissipation) via an elastic heat-conducting sheet, thereby ensuring a heat dissipation path for the heat-generating component.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2009-181737 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, in the construction of Patent Document 1, due to the accumulation of tolerances in the assembly of the inner shell and the heating element, and the assembly of the inner shell and the outer frame, it is unavoidable that the deviation in the distance between the opposing surfaces of the heating element and the outer frame will increase. As a result, with the increase in tolerances, the required thickness of the elastic heat-conducting sheet between the heating element and the outer frame increases, which may lead to a decrease in heat dissipation performance.

[0008] Therefore, a circuit unit is disclosed that can suppress gap deviation caused by the tolerance between the thermal contact part of the heat-generating component housed in the housing and the heat dissipation object, thereby improving heat dissipation performance.

[0009] Methods for solving problems

[0010] The circuit unit disclosed herein includes: a heat-generating component having a heat-contact portion that is in thermal contact with a heat-dissipating object and a fixing portion that is fixed to the heat-dissipating object; a housing for holding the heat-generating component; a holding portion protruding from the interior of the housing for holding the heat-generating component within the housing; an opening window that extends through the housing, exposing the heat-contact portion of the heat-generating component to the exterior of the housing; and an insertion hole that extends through the housing for insertion into the fixing portion of the heat-dissipating object. By fixing the fixing portion of the heat-generating component to the fixing portion inserted into the insertion hole, the heat-generating component is separated from the holding portion, and the heat-contact portion of the heat-generating component is in thermal contact with the heat-dissipating object.

[0011] Invention Effects

[0012] According to the circuit unit disclosed herein, the heat dissipation performance can be improved by suppressing the gap deviation caused by the tolerance between the thermal contact portion of the heat-generating component housed in the housing and the heat dissipation object. Attached Figure Description

[0013] Figure 1 This is a perspective view showing the circuit unit of Embodiment 1 in a fixed state relative to the heat dissipation object.

[0014] Figure 2 Is Figure 1 The circuit unit shown is represented in a perspective view after the upper casing, which constitutes the housing, has been removed.

[0015] Figure 3 Is Figure 2 The circuit unit shown is a top view representing the state after the upper casing has been removed.

[0016] Figure 4 It is an enlarged representation Figure 3 A longitudinal sectional view of the main part of section IV-IV.

[0017] Figure 5 It is an enlarged representation Figure 3 A longitudinal sectional view of the main part of the VV section.

[0018] Figure 6 yes Figure 1 The circuit unit shown is an exploded 3D view.

[0019] Figure 7 It indicates composition Figure 1 A top view of the lower housing of the circuit unit shown.

[0020] Figure 8 It is Figure 1 The diagram shown is a perspective view of the circuit unit before it is fixed relative to the heat dissipation object, and is a diagram of the circuit unit after the upper casing has been removed.

[0021] Figure 9 yes Figure 8 The longitudinal sectional view of the circuit unit shown is in contrast to... Figure 5 The corresponding diagram.

[0022] Figure 10 This is a perspective view showing the circuit unit of Embodiment 2 in a fixed state relative to the heat dissipation object, and a view showing the state with the upper casing removed.

[0023] Figure 11 Is Figure 10 The circuit unit shown is a top view representing the state after the upper casing has been removed.

[0024] Figure 12 It is an enlarged representation Figure 11 A longitudinal sectional view of the main part of section XII-XII.

[0025] Figure 13 It indicates composition Figure 10 A perspective view of the lower housing of the circuit unit shown.

[0026] Figure 14 It is Figure 10 The perspective view of the circuit unit shown is a perspective view of the state before it is fixed relative to the heat dissipation object, and a perspective view of the state after the upper casing is removed.

[0027] Figure 15 yes Figure 14 The longitudinal sectional view of the circuit unit shown is in contrast to... Figure 12 The corresponding diagram.

[0028] Figure 16 It is an enlarged representation Figure 15 A longitudinal sectional view of the main part of section XVI-XVI in the image. Detailed Implementation

[0029] <Description of embodiments of this disclosure>

[0030] First, embodiments of this disclosure will be described.

[0031] (1) The circuit unit of this disclosure comprises: a heating element having a heat contact portion that is in thermal contact with a heat dissipation object and a fixing portion that is fixed to the heat dissipation object; a housing for holding the heating element; a holding portion protruding from the interior of the housing for holding the heating element inside the housing; an opening window that is provided through the housing so that the heat contact portion of the heating element is exposed to the outside of the housing; and an insertion hole that is provided through the housing for insertion into the fixing portion of the heat dissipation object, wherein by fixing the fixing portion of the heating element to the fixing portion inserted into the insertion hole, the heating element is separated from the holding portion and the heat contact portion of the heating element is in thermal contact with the heat dissipation object.

[0032] According to the circuit unit of this method, by directly fixing the fixing part of the heating element held in the housing to the fixing part of the heat dissipation object inserted into the housing through the insertion hole provided in the housing, the heating element can be separated from the holding part of the housing, allowing the thermal contact part of the heating element to make thermal contact with the heat dissipation object. This eliminates the need for components between the heating element and the heat dissipation object, reducing the deviation in distance between the opposing surfaces of the heating element's thermal contact part and the heat dissipation object caused by tolerances compared to existing structures. Furthermore, by fixing the fixing part of the heating element to the fixing part of the heat dissipation object, the thermal contact part of the heating element exposed to the outside of the housing through the opening window of the housing can make thermal contact with the heat dissipation object, stably maintaining the contact state between the thermal contact part of the heating element and the heat dissipation object. Therefore, it is possible to suppress gap deviations caused by tolerances between the thermal contact part of the heating element housed in the housing and the heat dissipation object, thereby improving heat dissipation performance.

[0033] (2) In (1) above, it is preferable that, in the state of being fixed to the heat dissipation object, the thermal contact portion of the heat-generating component contacts the heat dissipation object via an elastic thermally conductive member. By placing the elastic thermally conductive member between the thermal contact portion of the heat-generating component and the heat dissipation object, deviations caused by the tolerance of the gap between the two opposing surfaces can be absorbed, and the generation of a gap between the opposing surfaces can be prevented, thereby further improving the heat dissipation performance.

[0034] (3) In (1) or (2) above, it is preferable that the retaining part includes a frame portion that surrounds the opening window and protrudes into the housing, and a retaining part that protrudes from the peripheral wall of the heating element is mounted on the protruding end face of the frame portion. Since the retaining part includes a frame portion that surrounds the opening window and protrudes into the housing, interference between the heating element and other components can be prevented by the frame portion. Furthermore, since the retaining part that protrudes from the peripheral wall of the heating element is mounted on the protruding end face of the frame portion, the heating element can be reliably prevented from flying out of the opening window. Thus, the heating element, in the case of a circuit unit being transported or otherwise fixed to the retaining part of the heat dissipation object, can be stably held within the housing.

[0035] (4) In (3) above, preferably, the retaining portion includes a flexible plate portion that protrudes inward from the frame portion into the housing and is capable of flexing outward to the outer periphery of the opening window. The flexible plate portion has a locking claw portion disposed at the protruding front end and protruding outward to the inner periphery of the opening window. The assembly of the heating element to the frame portion is allowed by the flexing outward to the outer periphery of the flexible plate portion. When the retaining portion of the heating element is placed on the protruding end face of the frame portion, the locking claw portion of the elastically restored flexible plate portion overlaps with the heating element in the protruding direction of the frame portion with a gap. The retaining portion also includes a flexible plate portion combined with the frame portion, wherein the locking claw portion disposed at the protruding front end of the flexible plate portion overlaps with the heating element placed on the protruding end face of the frame portion in the protruding direction of the frame portion with a gap. Therefore, it can not only prevent the heating component from flying out of the opening window, but also restrict the displacement of the heating component in the opposite direction by engaging with the locking claw, thus keeping the heating component more stably inside the housing.

[0036] (5) In (3) or (4) above, preferably, the fixing part of the heat-generating component is positioned at the same location as the holding part in the protruding direction of the frame portion, and in the state of being fixed to the heat dissipation object, the fixing part of the heat dissipation object is disposed inside the housing beyond the protruding end face in the protruding direction of the frame portion. In the protruding direction of the frame portion, the fixing part of the heat-generating component is positioned at the same location as the holding part placed on the protruding end face of the frame portion, and the fixing part of the heat dissipation object is disposed inside the housing beyond the protruding end face. Thus, by fixing the fixing part to the fixing part, the heat-generating component can be separated from the holding part (frame portion), and the fixing part of the heat-generating component can be directly fixed to the fixing part of the heat dissipation object. As a result, it is advantageous to avoid or suppress the reduction in heat dissipation performance caused by the superposition of tolerances.

[0037] (6) In any of (1) to (5) above, preferably, the housing includes a lower housing having the opening window and an upper housing overlapping the lower housing, the opening window having a rectangular shape, and the retaining portion including: a protruding wall portion respectively disposed on a pair of opposing sides of the opening window and protruding into the housing; a positioning wall portion disposed on one of the other pair of opposing sides of the opening window and protruding into the housing; and a displacement limiting rib disposed on the upper housing and disposed opposite to the positioning wall portion in such a way that the heating element is sandwiched in the middle, the heating element being disposed and positioned between the opposing surfaces of the positioning wall portion and the displacement limiting rib and between the opposing surfaces of the protruding wall portion, and a retaining portion protruding from the peripheral wall portion of the heating element disposed between the protruding wall portions being placed on the protruding end face of the protruding wall portion.

[0038] The heating element is inserted between the protruding walls relative to the lower housing in a sliding manner from the side opposite to the positioning wall towards the positioning wall, and abuts against the positioning wall, thereby easily positioning it in a predetermined position. Furthermore, by assembling the upper housing, the heating element can be positioned between the opposing surfaces of the positioning wall and the displacement limiting rib, and between the opposing surfaces of the protruding walls. In addition, a retaining portion protruding from the peripheral wall of the heating element positioned between the protruding walls is mounted on the protruding end face of the protruding wall, thus reliably preventing the heating element from flying out of the opening. Therefore, the heating element can be stably held within the housing in states such as when the circuit unit is being transported to the fixing part of the heat dissipation object.

[0039] (7) In (6) above, preferably, the retaining part includes a displacement limiting piece that extends from the protruding front end of the positioning wall towards the heating element, is positioned closer to the inner side of the housing than the protruding end face of the protruding wall, and is positioned opposite the heating element with a gap. The displacement limiting piece is provided at the protruding front end of the positioning wall, positioned closer to the inner side of the housing than the protruding end face of the protruding wall, and positioned opposite the heating element with a gap. This not only prevents the heating element from flying out of the opening window, but also restricts the displacement of the heating element in the opposite direction by engaging with the displacement limiting piece, thus holding the heating element more stably within the housing.

[0040] (8) In (6) or (7) above, preferably, the fixing part of the heat-generating component is positioned at the same location as the holding part in the protruding direction of the protruding wall portion, and in the state of being fixed to the heat dissipation object, the fixing part of the heat dissipation object is disposed inside the housing beyond the protruding end face in the protruding direction of the protruding wall portion. In the protruding direction of the protruding wall portion, the fixing part of the heat-generating component is positioned at the same location as the holding part placed on the protruding end face of the protruding wall portion, and the fixing part of the heat dissipation object is disposed inside the housing beyond the protruding end face. Thus, by fixing the fixing part to the fixing part, the heat-generating component can be separated from the holding part (protruding wall portion), and the fixing part of the heat-generating component can be directly fixed to the fixing part of the heat dissipation object. As a result, it is advantageous to avoid or suppress the reduction in heat dissipation performance caused by the superposition of tolerances.

[0041] <Details of the embodiments of this disclosure>

[0042] The following description, with reference to the accompanying drawings, illustrates specific examples of the circuit units of this disclosure. It should be noted that this disclosure is not limited to these examples, as indicated by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0043] <Implementation Method 1>

[0044] The following uses Figures 1 to 9 The circuit unit 10 of Embodiment 1 of this disclosure will be described. This circuit unit 10 is, for example, mounted in an electric vehicle or a hybrid vehicle, and connected between an on-board power source (e.g., a battery, not shown) and a load (e.g., an inverter, not shown). It should be noted that in a vehicle, the circuit unit 10 can be configured in any orientation, but hereafter, the top will be considered the orientation. Figure 4 Above, set below to Figure 4 Below the middle, set the left side as Figure 3 Set the left side to the right side. Figure 3 To the right of the center, set the front to Figure 3 Below the middle, set the back to Figure 3 The description will be provided above. Additionally, for multiple identical components, sometimes only some components are labeled with reference numerals, while the reference numerals for the other components are omitted.

[0045] <Circuit Unit 10>

[0046] The circuit unit 10 includes a heat-generating component, which has a heat-contact portion 14 that makes thermal contact with the heat dissipation object (the frame 12 described later) and a fixing portion 16 that is fixed to the heat dissipation object (the frame 12). It should be noted that the circuit unit 10 of Embodiment 1 includes a relay 18, a pre-charge relay 20, and a pre-charge resistor 22 as electrical components that generate heat when energized. However, in Embodiment 1, the structure disclosed herein is applied to the pre-charge resistor 22 among the aforementioned electrical components; therefore, the heat-generating component is composed of the pre-charge resistor 22. Furthermore, the circuit unit 10 includes a housing 24 that holds the heat-generating component (pre-charge resistor 22). In Embodiment 1, the housing 24 not only houses and holds the pre-charge resistor 22 but also houses and holds the relay 18 and the pre-charge relay 20.

[0047] Furthermore, the circuit unit 10 includes: a holding part 26, which protrudes into the interior of the housing 24 to hold the heating element (pre-charge resistor 22) inside the housing 24; an opening window 28, which is provided through the housing 24 to expose the thermal contact part 14 of the heating element (pre-charge resistor 22) to the outside of the housing 24; and an insertion hole 30, which is provided through the housing 24 for insertion into the fixing part 42, which is provided on the heat dissipation object (frame 12) as described later.

[0048] <Heat dissipation object (frame 12)>

[0049] The circuit unit 10 and the aforementioned vehicle power supply battery can be housed in, for example, a metal frame 12, thus forming a battery pack (not shown). That is, the circuit unit 10 is stacked and fixed on the upper surface 32 of the frame 12, and heat generated by energizing the electrical components disposed within the circuit unit 10 is dissipated through the frame 12. Therefore, in Embodiment 1, the heat dissipation object for cooling the heat generated in the circuit unit 10 is the metal frame 12. It should be noted that, in the figures, a flat metal plate constituting the bottom wall of the frame 12 is shown, such as... Figure 1 As shown, for example, a refrigerant flow path 34 can be formed inside the metal plate. The refrigerant flowing within the refrigerant flow path 34 is a known refrigerant. Furthermore, Figure 1 The extension direction and length of the refrigerant flow path 34 shown are merely illustrative, and there are no limitations on the extension direction and length of the refrigerant flow path.

[0050] And, as well as Figure 6 As shown, on the upper surface 32 of the frame 12, support portions 36 for supporting the four corners of the circuit unit 10 are provided at four locations around the fixed position of the circuit unit 10, protruding upwards. A bolt fastening hole 40 is formed in the center of each support portion 36, opening upwards, for fastening the bolt 38 that secures the circuit unit 10. Furthermore, on the upper surface 32 of the frame 12, at a predetermined location at the fixed position of the circuit unit 10, a fixed portion 42 is provided, protruding upwards, for fixing the fixing portion 16 of the heating element (pre-charge resistor 22). In Embodiment 1, the two fixed portions 42, 42 are spaced a predetermined distance apart in the front-rear direction, and each fixed portion 42 has a predetermined protrusion dimension. In particular, in Embodiment 1, each fixed portion 42 is generally prismatic in shape, and a screw fastening hole 46 is formed at the upper end of each fixed portion 42 for fastening the screw 44 used to fix the fixing portion 16 and the fixed portion 42.

[0051] <Relay 18>

[0052] In Embodiment 1, a pair of relays 18, 18 are provided in the circuit unit 10, arranged separately from each other in the left-right direction. One relay (right side in Embodiment 1) is a positive-side relay 18a, and the other relay (left side in Embodiment 1) is a negative-side relay 18b. These positive-side and negative-side relays 18a, 18b each have a pair of terminal portions 48, 48 separated from each other in the left-right direction on the front side (positive-side relay 18a is in the front, negative-side relay 18b is in the rear). Figure 4 (As shown in the diagram), each terminal portion 48 is exposed on the surface of each relay 18a, 18b.

[0053] Each terminal portion 48 serves as both an input and output terminal for each relay 18a and 18b. For example, in the positive-side relay 18a, the left terminal portion 48 is the positive-side input terminal, and the right terminal portion 48 is the positive-side output terminal. Similarly, in the negative-side relay 18b, the left terminal portion 48 is the negative-side output terminal, and the right terminal portion 48 is the negative-side input terminal.

[0054] The terminal portions 48 of each of these relays 18a and 18b are overlapped with energized busbars 50 and fixed by bolts 52. That is, the circuit unit 10 has first and second energized busbars 50a and 50b connected to the input and output terminals 48 and 48 of the positive-side relay 18a, and third and fourth energized busbars 50c and 50d connected to the input and output terminals 48 and 48 of the negative-side relay 18b. When the circuit unit 10 is assembled, the ends of the first to fourth energized busbars 50a to 50d are exposed to the outside through through windows 106a to 106d provided in the upper housing 98 (described later) in the housing 24, respectively forming the input and output connection portions 54a and 54b on the positive side and the input and output connection portions 54c and 54d on the negative side.

[0055] Furthermore, the input connection 54a on the positive side and the input connection 54c on the negative side are electrically connected to the positive and negative terminals of a battery (not shown) via conductive members composed of busbars, wires, etc. Additionally, the output connection 54b on the positive side and the output connection 54d on the negative side are electrically connected to the positive and negative terminals of an inverter (not shown) via conductive members. These connections 54a-54d and conductive members can be secured with bolts 56.

[0056] Thus, the main circuit 58 between the battery and the inverter is formed by the relays 18a and 18b, the first to fourth energizing busbars 50a to 50d, and the aforementioned conducting components. Furthermore, in this main circuit 58, the energized and de-energized states of the main circuit 58 are switched between the battery and the inverter by switching the relays 18a and 18b on and off.

[0057] In addition, on each terminal portion 48 of the positive and negative relays 18a and 18b, besides the first to fourth energizing busbars 50a to 50d, first to fourth heat dissipation busbars 60a to 60d are also fastened together by bolts 52. The first to fourth heat dissipation busbars 60a to 60d are approximately L-shaped, having a portion extending in the vertical direction and a portion extending horizontally (orthogonal to the vertical direction) from the lower end of the portion extending in the vertical direction. Each heat dissipation busbar 60a to 60d is fixed to each terminal portion 48 of each relay 18a and 18b at its upper end by bolts 52, and its lower end extends in the front-back direction and is located below each relay 18a and 18b.

[0058] A heat dissipation section 62 is formed by the portion extending in the front-rear direction from the lower end of each of these heat dissipation busbars 60a to 60d. Each heat dissipation section 62 is in thermal contact with the frame 12, which is the object to be dissipated, via an insulating sheet 64 and an elastic thermally conductive member 66. Known materials can be used as the insulating sheet 64 and the elastic thermally conductive member 66, especially the elastic thermally conductive member 66, for example, a thermally conductive sheet or a gap filler with good thermal conductivity can be used. With such a configuration, each terminal portion 48 of each relay 18a and 18b is in thermal contact with the frame 12 via each heat dissipation busbar 60a to 60d, the insulating sheet 64, and the elastic thermally conductive member 66, and the heat generated when each relay 18a and 18b is energized can be dissipated from the frame 12.

[0059] <Pre-charging circuit 68>

[0060] The pre-charge circuit 68 is connected in parallel with the positive-side relay 18a in the main circuit 58. Specifically, in the pre-charge circuit 68, the pre-charge relay 20 and the pre-charge resistor 22 are connected in series. Furthermore, the pre-charge relay 20 is electrically connected to the input terminal 48 of the positive-side relay 18a via a wire 70, and the pre-charge resistor 22 is electrically connected to the output terminal 48 of the positive-side relay 18a via a wire 72. Additionally, the pre-charge relay 20 and the pre-charge resistor 22 are electrically connected via a wire 74.

[0061] A terminal 76 is provided at the end of at least one of the wires 70, 72, 74, and each terminal 76 overlaps with each terminal portion 48 of the positive side relay 18a or each terminal portion 80 of the pre-charge relay 20 (described later) and is fixed by bolts 52 or screws 78.

[0062] <Precharge relay 20>

[0063] As a pre-charge relay 20, a known construction can be adopted, and its construction is not limited, but it has a pair of terminal portions 80, 80 that are separated from each other in the left-right direction (in Figure 4 (One is shown in the figure). In Embodiment 1, the pre-charge relay 20 is arranged with its top surface facing outwards, and each terminal portion 80 is exposed on the upper surface of the pre-charge relay 20. Furthermore, the terminal 76 provided at the end of the wire 70 connecting the positive-side relay 18a to the pre-charge relay 20 overlaps with the input terminal portion 80 (the left terminal portion 80) of the pre-charge relay 20 and is fixed by screws 78. In addition, the terminal 76 provided at the end of the wire 74 connecting the pre-charge relay 20 to the pre-charge resistor 22 overlaps with the output terminal portion 80 (the right terminal portion 80) of the pre-charge relay 20 and is fixed by screws 78.

[0064] <Pre-charge resistor 22>

[0065] The pre-charge resistor 22 is constructed using a metal-cased resistor. As the pre-charge resistor 22 (metal-cased resistor), a known construction can be employed, therefore detailed description is omitted, but the wire-wound resistor (not shown) is encased in an insulated state within the metal casing 82. It should be noted that... Figure 5 In the cross-sectional view, the internal structure of the pre-charge resistor 22 is omitted, and only the metal housing 82 is shown. In other words, the metal housing 82 of the pre-charge resistor 22 is hollow, and a wire-wound resistor (not shown) is housed inside the metal housing 82 in an insulated state. In Embodiment 1, the metal housing 82 of the pre-charge resistor 22 is a hollow, generally rectangular parallelepiped, arranged in a direction extending in the front-rear direction. That is, the metal housing 82 is configured to include: a generally cylindrical peripheral wall portion 84, configured to include walls on both sides in the front-rear direction and both sides in the left-right direction; an upper wall portion 86, covering the upper opening of the peripheral wall portion 84; and a lower wall portion 88, covering the lower opening of the peripheral wall portion 84.

[0066] In particular, in Embodiment 1, flange-like portions 90 protruding in both directions are provided on the upper end of the peripheral wall portion 84 (or the upper wall portion 86) of the metal housing 82. Each of these flange-like portions 90 has a width (left-right direction) dimension approximately equal to that of the upper wall portion 86 (or the peripheral wall portion 84) and a predetermined protrusion dimension (front-back direction dimension). A screw-through groove 92 for inserting the aforementioned screw 44 for fixing the pre-charge resistor 22 is provided in the central portion in the left-right direction of each flange-like portion 90. By providing these flange-like portions 90, in the projection in the vertical direction, the upper surface (upper surface of the upper wall portion 86) 93a of the pre-charge resistor 22 has an area larger than the lower surface (lower surface of the lower wall portion 88) 93b of the pre-charge resistor 22.

[0067] As described later, each flange-shaped portion 90 overlaps with each fixed portion 42 in the frame 12, and each screw 44 is inserted into the screw insertion slot 92 and fastened to the screw fastening hole 46, thereby fixing the fixing portion 16 in the heating element (pre-charge resistor 22) to the fixed portion 42. Therefore, in each flange-shaped portion 90, the portion around the screw insertion slot 92 (the central portion in the left-right direction of each flange-shaped portion 90) constitutes the fixing portion 16. In addition, the left-right end portions of each flange-shaped portion 90 are placed on the retaining portion 26 protruding into the housing 24 (the lower housing 100 described later), thereby retaining the heating element (pre-charge resistor 22) within the housing 24. Therefore, the left-right end portions of each flange-shaped portion 90 constitute the retaining portion 94. Thus, in Embodiment 1, each fixing portion 16 and each retaining portion 94 are provided in each flange-shaped portion 90, and are generally provided in the same position in the vertical direction.

[0068] As described above, the pre-charge resistor 22 is connected to a wire 72 connected to the positive-side relay 18a and a wire 74 connected to the pre-charge relay 20. Specifically, a wire 72 is connected to one end of a winding disposed inside the pre-charge resistor 22, and a wire 74 is connected to the other end. Furthermore, the wires 72 and 74 connected to both ends of the winding extend outward from the inside of the metal housing 82. In Embodiment 1, the wires 72 and 74 extend outward from one end (the front end in Embodiment 1) along the length of the metal housing 82. Moreover, the terminals 76 disposed at the ends of these wires 72 and 74 overlap with the output terminal portion 48 of the positive-side relay 18a and the output terminal portion 80 of the pre-charge relay 20, respectively, and are fixed by bolts 52 and screws 78.

[0069] The metal casing 82 of the pre-charge resistor 22 (metal-cased resistor) has a thermal contact portion 14 that is in thermal contact with the frame 12, which serves as a heat dissipation object. In Embodiment 1, with the circuit unit 10 fixed to the frame 12 as described later, the metal casing 82 overlaps with the frame 12 via an elastic thermally conductive member 96 that overlaps with the lower surface 93b, and the lower wall portion 88 of the hollow metal casing 82 forms the thermal contact portion 14. The elastic thermally conductive member 96 can be made of the same material as the elastic thermally conductive member 66 located below each relay 18a, 18b. It should be noted that these elastic thermally conductive members 66, 96 can be initially rectangular sheets, or they can be initially gel- or grease-like and cured into sheets by applying heat or light.

[0070] <Shell 24>

[0071] As previously described, the circuit unit 10 has a housing 24 that holds the relays 18a, 18b, the pre-charge relay 20, and the pre-charge resistor 22. In Embodiment 1, the housing 24 is generally a hollow cuboid, with its left-right dimension larger than its front-back dimension. In particular, in Embodiment 1, the housing 24 is configured to include an upper housing 98 and a lower housing 100 that can be assembled and disassembled in the vertical direction. These upper housings 98 and lower housings 100 are, for example, formed of synthetic resin. The method of fixing the upper housing 98 and the lower housing 100 is not limited, but in Embodiment 1, with the upper housing 98 and the lower housing 100 overlapping, the aforementioned bolts 38 are inserted through the four corners of the circuit unit 10 and fastened to the bolt fastening holes 40 provided in each support portion 36 of the frame 12, thereby fixing the upper housing 98 and the lower housing 100 to each other.

[0072] The upper housing 98 is generally box-shaped with an opening to the bottom, and includes an upper bottom wall 102 and an upper upper wall 104 protruding downward from the outer periphery of the upper bottom wall 102. In the upper bottom wall 102, rectangular through windows 106a-106d extending in the thickness direction (vertical direction) are provided at positions corresponding to the connecting portions 54a-54d of the first to fourth power-conducting busbars 50a-50d when the circuit unit 10 is assembled. Mounting portions 110 with bolt insertion holes 108 are provided at the four corners of the upper housing 98, each mounting portion 110 being located slightly above the lower end of the upper upper wall 104. In addition, on the upper bottom wall portion 102, circular through holes 112 extending in the thickness direction are provided at positions corresponding to the insertion holes 30 of the lower housing 100 in the state where the circuit unit 10 is assembled. Each screw 44 is fastened from above to the bolt fastening hole 40 of each fixed portion 42 through the through holes 112.

[0073] Also Figure 7 As shown, the lower housing 100 has a bottom wall portion 114 that is integrally flat, and the bottom wall portion 114 is rectangular in shape, which is approximately the same as that of the upper housing 98 when viewed from above. Thus, when the upper housing 98 and the lower housing 100 are overlapped and fixed, the lower opening of the upper housing 98 is covered by the bottom wall portion 114 of the lower housing 100.

[0074] In the bottom wall portion 114, rectangular openings 116 extending in the thickness direction (vertical direction) are provided at positions corresponding to the heat dissipation portions 62 of the first to fourth heat dissipation busbars 60a to 60d when the circuit unit 10 is assembled. Additionally, in the bottom wall portion 114, the aforementioned openings 28 extending in the thickness direction (vertical direction) are provided at positions corresponding to the thermal contact portion 14 (lower wall portion 88 of the metal housing 82) of the pre-charge resistor 22 (metal-cased resistor) when the circuit unit 10 is assembled. In Embodiment 1, the opening 28 is rectangular and has an area larger than the lower surface 93b of the pre-charge resistor 22 when viewed from above. Therefore, when the circuit unit 10 is assembled, the opening 28 exposes the thermal contact portion 14 (lower wall portion 88) of the metal housing 82 in a manner that allows it to make thermal contact with the frame 12. Furthermore, insertion holes 30 are formed on both sides of the opening window 28 in the front-rear direction for inserting the fixing parts 42 of the frame 12. These insertion holes 30 have a generally rectangular shape. In Embodiment 1, the opening window 28 is connected to each insertion hole 30, and the insertion holes 30 are formed connectedly on both sides of the inner peripheral surface of the opening window 28 in the front-rear direction.

[0075] In Embodiment 1, insulating sheets 64 and elastic thermally conductive members 66 are stacked in each opening 116 located below each heat dissipation section 62. Thus, each heat dissipation section 62 in the first to fourth heat dissipation busbars 60a to 60d contacts the frame 12 overlapping the bottom wall portion 114 in an electrically insulated and thermally conductive state. It should be noted that the insulating sheet 64 and the elastic thermally conductive member 66 do not need to be different components; they can be a single component with both insulating and thermally conductive properties. These insulating sheets 64 and elastic thermally conductive members 66 are, for example, fixed (e.g., bonded) to the lower surface of each heat dissipation section 62 when the circuit unit 10 is fixed to the frame 12, such as... Figure 4 As shown, when the circuit unit 10 is fixed to the frame 12, each insulating sheet 64 and each elastic heat-conducting member 66 are arranged in a receiving state inside each opening window 116.

[0076] Furthermore, an elastic thermally conductive member 96 is housed in the opening 28 below the thermal contact portion 14 in the pre-charge resistor 22. Thus, the thermal contact portion 14 contacts the frame 12 in a thermally conductive state. The wire-wound resistor constituting the pre-charge resistor 22 is housed in an insulated state within the metal housing 82; therefore, even when the circuit unit 10 is energized, the metal housing 82 remains electrically insulated, and the insulating sheet 64 need not be disposed within the opening 28. For example, when the circuit unit 10 is fixed to the frame 12, it is fixed (e.g., bonded) to the lower surface 93b of the thermal contact portion 14 (the lower wall portion 88 of the metal housing 82), and when the circuit unit 10 is fixed to the frame 12, the elastic thermally conductive member 96 is disposed in a housed state inside the opening 28.

[0077] Furthermore, mounting portions 120 with bolt insertion holes 118 are provided at the four corners around the lower housing 100 (bottom wall portion 114), and each mounting portion 120 is located at a certain position above the other parts of the bottom wall portion 114. In other words, recesses that are recessed upward relative to other parts are formed at the four corners around the lower surface 121 of the lower housing 100. Thus, by forming mounting portions 110 and 120 at the four corners around the outer periphery of the upper housing 98 and the outer periphery of the lower housing 100, corresponding concave and convex shapes are provided. As a result, when the upper housing 98 and the lower housing 100 overlap in the vertical direction, the upper housing 98 and the lower housing 100 can be positioned relative to each other in the horizontal direction by the fitting of these concave and convex shapes.

[0078] <Maintenance Section 26>

[0079] Furthermore, the lower housing 100 includes the aforementioned retaining portion 26, which includes a frame portion 122 that surrounds the opening window 28 and protrudes upwards into the housing 24. That is, the protruding direction of the frame portion 122 is vertical (particularly from below to above). Specifically, the frame portion 122 has a pair of sidewall portions 124, 124 extending in the front-rear direction at the left-right edges of the opening window 28, each sidewall portion 124 having a larger front-rear dimension than the opening window 28. Moreover, the front-rear ends of each sidewall portion 124 are bent into a crank shape, and the two ends of each sidewall portion 124 are located, via the bending portion 126, further inwards in the left-right direction than the middle portion in the front-rear direction. The two ends of each sidewall portion 124 in the front-rear direction are mounting portions 128 for mounting the flange-like portions 90 in the metal housing 82 of the pre-charge resistor 22.

[0080] Each mounting portion 128 is located further outward in the front-rear direction than the opening window 28. In Embodiment 1, each insertion hole 30 is formed connected at both ends of the opening window 28 in the front-rear direction, so each mounting portion 128 is provided on both sides of each insertion hole 30 in the left-right direction. In other words, at both ends of the frame portion 122 in the front-rear direction, an insertion window 129 that passes through in the front-rear direction is provided between each mounting portion 128, and the inside and outside of the frame portion 122 are interconnected through the insertion window 129. In Embodiment 1, two wires 72 and 74 extend from the front end of the pre-charging resistor 22. When the pre-charging resistor 22 is held in the frame portion 122 (holding portion 26), each wire 72 and 74 extends outward through the front insertion window 129. However, depending on the wiring method of the pre-charging circuit 68, each wire 72 and 74 can also extend outward through the rear insertion window 129.

[0081] More specifically, each flange-shaped portion 90 of the metal housing 82 (especially the retaining portion 94 which are the two ends in the left and right direction) is placed at the front and rear ends of the protruding end face (upper end face) 130 of the frame portion 122, that is, the protruding end face 130 of each mounting portion 128.

[0082] Here, the upward protrusion dimension of the frame portion 122 (the vertical dimension from the upper surface of the bottom wall portion 114 to the protruding end face 130) A (refer to...) Figure 9 The upward protrusion dimension (vertical dimension from the upper surface 32 of the frame 12 to the upper surface of each fixed part 42) B of the fixed part 42 is greater than that of the fixed part 42 in the frame 12. (Refer to) Figure 5 Small. In particular, as described later, with the circuit unit 10 fixed to the frame 12, each fixed part 42 protrudes into the interior of the circuit unit 10 through each insertion hole 30 of the lower housing 100, and each fixed part 42 is disposed on the inner side (upper) of the housing 24 beyond the protruding end face 130 in the protruding direction (vertical direction) of the frame part 122. In summary, with the circuit unit 10 fixed to the frame 12, the upper surface of each fixed part 42 is located above the protruding end face 130 of the frame part 122.

[0083] <Flexion section 132>

[0084] Furthermore, the retaining portion 26 includes a flexible sheet portion 132 that protrudes upwards from the frame portion 122 into the housing 24 and is capable of flexing and deforming (elastic deformation in Embodiment 1) towards the outer periphery of the opening window 28. In Embodiment 1, the flexible sheet portions 132 are provided at the midpoint of each side wall portion 124 in the front-rear direction. In particular, in Embodiment 1, a pair of flexible sheet portions 132, 132 are provided separately from each other in the front-rear direction at the midpoint of each side wall portion 124. Therefore, in Embodiment 1, a total of four flexible sheet portions 132 are provided in the retaining portion 26.

[0085] Each flexible plate portion 132 has a locking claw portion 134 disposed at the protruding front end (upper end) and protruding towards the inner peripheral side (inner side in the left-right direction) of the opening window 28. With the pre-charge resistor 22 assembled in the lower housing 100, each locking claw portion 134 protrudes inward in the left-right direction to a position overlapping with the upper wall portion 86 of the pre-charge resistor 22 (metal housing 82) in the vertical direction. In other words, in a top view projection with the pre-charge resistor 22 assembled in the lower housing 100, the protruding top end (inner side in the left-right direction) of each locking claw portion 134 overlaps with the left-right side edges of the upper wall portion 86.

[0086] Furthermore, each locking claw portion 134 has an inclined surface 136 on its upper surface that gradually slopes downwards as it moves inwards in the left and right directions. As a result, when assembling the pre-charge resistor 22 into the holding portion 26, by bringing the pre-charge resistor 22 close to the holding portion 26 from above, the left and right side edges of the lower surface 93b of the metal housing 82 abut against the inclined surface 136 of each locking claw portion 134, causing each flexible piece portion 132 to elastically deform outwards in the left and right directions. This allows the pre-charge resistor 22 to be assembled into the frame portion 122. In addition, when each flange-shaped portion 90 of the metal housing 82 is placed on the protruding end face 130 of each mounting portion 128, each flexible piece portion 132 elastically recovers its deformation (elastic recovery), thereby also... Figure 9 As shown, the locking claw portions 134 of each flexural plate portion 132 overlap with the pre-charge resistor 22 in the protruding direction (vertical direction) of the frame portion 122, separated by a gap 138.

[0087] Assembly of Circuit Unit 10

[0088] The following describes a specific example of the assembly method of circuit unit 10. It should be noted that the assembly method of circuit unit 10 is not limited to the method described below.

[0089] First, the first to fourth power-conducting busbars 50a to 50d and the first to fourth heat-dissipating busbars 60a to 60d are overlapped with the terminal portions 48 of each relay 18a and 18b, and are fixed with bolts 52. At this time, the terminals 76 at the ends of each wire 70 and 72 are also overlapped with the terminal portions 48 of the positive-side relay 18a and are tightened with bolts 52. Furthermore, the relays 18a and 18b and the pre-charge relay 20 are mounted on the lower housing 100 and fixed with bolts or screws.

[0090] Furthermore, the pre-charge resistor 22 is brought close to the holding portion 26 of the lower housing 100 from above, causing each flexible piece 132 to elastically deform outward in the left-right direction and be assembled. The locking claws 134 of each flexible piece 132 pass over the upper wall portion 86 of the metal housing 82, and each flexible piece 132 elastically recovers its deformation. Thus, each flange-shaped portion 90 of the metal housing 82 is placed on the protruding end face 130 of each mounting portion 128 of the holding portion 26, and the holding portion 26 holds each held portion 94 at both ends of each flange-shaped portion 90 in the left-right direction. In this state, the inner ends of each locking claw 134 in the left-right direction overlap with the two side edges of the upper wall portion 86 in the vertical direction. For example, even when the pre-charge resistor 22 is displaced upward, the locking claws 134 engage with the upper wall portion 86, preventing the pre-charge resistor 22 from detaching from the holding portion 26 upward. In other words, in this state, the pre-charge resistor 22 can be displaced in the vertical direction within each gap 138, and the pre-charge resistor 22 is temporarily assembled to the lower housing 100.

[0091] Next, as Figure 8 As shown, the upper housing 98 approaches from above the lower housing 100, which is assembled with relays 18a, 18b, pre-charge relay 20, and pre-charge resistor 22 as described above. Figure 9 The upper housing 98 and the lower housing 100 are overlapped. Thus, the mounting portions 110 of the upper housing 98 overlap with the mounting portions 120 of the lower housing 100, and as described above, the concave and convex shapes of the outer peripheral portions of the upper housing 98 and the lower housing 100 fit together. As a result, horizontal displacement of the upper housing 98 and the lower housing 100 is prevented, completing the circuit unit 10 of Embodiment 1. It should be noted that in the circuit unit 10 before assembly with the frame 12, for example, the upper housing 98 and the lower housing 100 can be kept from separating in the vertical direction by inserting bolts 38 into the bolt holes 108 and 118 at the four corners.

[0092] Assembly of Circuit Unit 10 to Heat Dissipation Target (Frame 12)

[0093] The following describes a specific example of a method for assembling the circuit unit 10 into the housing 12, which serves as a heat sink. It should be noted that the method of assembling the circuit unit 10 into the housing 12 is not limited to the method described below.

[0094] First, the circuit unit 10, manufactured as described above, is superimposed on a predetermined location on the upper surface 32 of the frame 12. It should be noted that... Figure 2 , Figure 3For ease of understanding, the upper housing 98 is shown separated from the lower housing 100, but the circuit unit 10 is assembled as a single unit relative to the frame 12. At this time, each heat dissipation portion 62 in each of the heat dissipation busbars 60a-60d is stacked and fixed with each insulating sheet 64 and each elastic heat-conducting member 66, and the elastic heat-conducting member 96 is fixed to the lower wall portion 88 of the pre-charge resistor 22 (metal housing 82). Furthermore, the circuit unit 10 overlaps the upper surface 32 with each support portion 36 protruding from the upper surface 32 of the frame 12 fitting into the recess created by the mounting portion 120 provided on the lower surface of the circuit unit 10 (lower surface 121 of the lower housing 100). Thus, the circuit unit 10 and the frame 12 are positioned horizontally, and the bolt insertion holes 108, 118 at the four corners of the circuit unit 10 communicate vertically with the bolt fastening holes 40 in each support portion 36.

[0095] Then, by overlapping the circuit unit 10 onto the upper surface 32 of the frame 12, each fixed portion 42 protruding upward from the upper surface 32 is inserted into the circuit unit 10 through each insertion hole 30 provided in the lower housing 100. In particular, as described above, with the lower surface of the circuit unit 10 (the lower surface 121 of the lower housing 100) overlapping the upper surface 32 of the frame 12, the upper surface of each fixed portion 42 protrudes upward beyond the protruding end face 130 of each frame portion 122. As a result, with the lower surface 121 of the circuit unit 10 overlapping the upper surface 32 of the frame 12, the upper surface of each fixed portion 42 abuts against each flange-like portion 90 of each metal housing 82 from below, and these flange-like portions 90 (in particular each retained portion 94) separate upward from the protruding end face 130 of the retaining portion 26 (in particular the mounting portion 128). As a result, the screw insertion slots 92 of each flange 90 are connected to the screw fastening holes 46 of each fixed part 42 in the vertical direction.

[0096] From this state, bolts 38 are inserted into the bolt holes 108 and 118 at the four corners of the circuit unit 10 and tightened into the bolt fastening holes 40. Additionally, screws 44 are inserted into the screw slots 92 through the through holes 112 in the upper housing 98 and tightened into the screw fastening holes 46, fixing the fixing parts 16 formed by the portion surrounding each screw slot 92 to each fixed part 42. Thus, the assembly of the circuit unit 10 relative to the frame 12 is completed. With the circuit unit 10 assembled in the frame 12, each heat dissipation part 62 in each heat dissipation busbar 60a-60d is in thermal contact with the frame 12 via each insulating sheet 64 and each elastic thermally conductive member 66, and the thermal contact part 14 in the pre-charge resistor 22 is in thermal contact with the frame 12 via the elastic thermally conductive member 96. With the circuit unit 10 assembled in the frame 12, the insulating sheets 64 and the elastic heat-conducting members 66, 96 are preferably slightly compressed between the heat dissipation part 62, the thermal contact part 14 (lower wall part 88) and the frame 12 in the vertical direction.

[0097] As described above, each connection portion 54a to 54d of the circuit unit 10 assembled within the battery pack housing 12 is electrically connected to the battery and inverter via a conductive member (not shown). Thus, the battery and inverter are electrically connected via the circuit unit 10.

[0098] Generally, when a vehicle starts, electricity flows from the battery to the inverter to charge the capacitors inside the inverter. However, the starting current (inrush current) is relatively large. If the inrush current flows through the main circuit, the main relay may be damaged. A pre-charging resistor is installed to prevent this damage. Specifically, when the vehicle starts, the positive-side relay 18a is disconnected, and the pre-charging relay 20 is connected. Power is then supplied from the battery to the capacitors inside the inverter via the pre-charging circuit 68, preventing damage to the positive-side relay 18a and charging the capacitors. After the vehicle starts, the positive-side relay 18a is connected, and the pre-charging relay 20 is disconnected. Power is then supplied from the battery to the inverter via the main circuit 58. Therefore, when the vehicle starts, the pre-charging circuit 68 is energized, causing the pre-charging resistor 22 to heat up. After the vehicle starts, the main circuit 58 is energized, causing the relays 18a and 18b to heat up. That is, the timing of the pre-charge resistor 22 heating up is different from that of the positive side relay 18a.

[0099] In contrast, the frame 12, which is in thermal contact with the thermal contact portion 14, is also in thermal contact with the positive-side relay 18a. Therefore, a common heat dissipation path can be formed between the pre-charge resistor 22 and the positive-side relay 18a, which have different timing for heat generation. This avoids an increase in the number of components compared to the case where different heat dissipation paths are formed between the pre-charge resistor 22 and the positive-side relay 18a.

[0100] In the circuit unit 10 of Embodiment 1 constructed as described above, a metal-cased resistor capable of handling large currents is used as the pre-charge resistor 22. That is, the metal-cased resistor houses an insulated wire-wound resistor within a metal casing 82, allowing heat dissipation through the metal casing 82. Therefore, the heat dissipation performance of the metal-cased resistor is superior to that of a ceramic resistor, and even where multiple ceramic resistors are required, a smaller number (e.g., one) can handle large currents in the metal-cased resistor. As a result, the mounting space for the pre-charge resistor can be reduced, enabling miniaturization of the circuit unit 10.

[0101] In particular, in the circuit unit 10, before installation onto the frame 12, which serves as a heat dissipation object, a pre-charge resistor 22, which is a heat-generating component, is held in the holding portion 26 of the housing 24. However, during installation onto the frame 12, the pre-charge resistor 22 is separated from the holding portion 26, and each fixing portion 16 in the pre-charge resistor 22 is directly fixed to each fixing portion 42 in the frame 12. As a result, tolerances in the housing 24 do not need to be considered, and the thermal contact portion 14 in the pre-charge resistor 22 can make more reliable thermal contact with the frame 12.

[0102] Specifically, an elastic heat-conducting member 96 is provided between the thermal contact portion 14 and the frame 12. This prevents an air layer from existing between the thermal contact portion 14 and the frame 12, thereby improving heat dissipation efficiency. Furthermore, in conventional configurations where the pre-charge resistor is fixed to the housing and the housing is fixed to the frame to make thermal contact with the frame, tolerances in the housing must be considered, requiring the elastic heat-conducting member to be thick-walled. In other words, by directly fixing the pre-charge resistor 22 and the frame 12 as in Embodiment 1, tolerances in the housing 24 are not considered, allowing the elastic heat-conducting member 96 to be thin-walled, thus improving thermal conductivity.

[0103] The retaining portion 26 includes a frame portion 122 surrounding the opening window 28 and protruding towards the inside of the housing 24. Before the circuit unit 10 is fixed to the frame 12, a retaining portion 94 (flange-shaped portion 90) protruding outward from the peripheral wall portion 84 of the pre-charge resistor 22 is mounted on the protruding end face 130 of the frame portion 122. This prevents the pre-charge resistor 22 from being pulled out through the opening window 28 in the circuit unit 10. In particular, in embodiment 1, the frame portion 122 includes a pair of sidewall portions 124, 124 facing each other in the left-right direction. With the pre-charge resistor 22 held in the retaining portion 26, displacement of the pre-charge resistor 22 in the left-right direction is also suppressed. As a result, displacement of the pre-charge resistor 22 within the housing 24 can be suppressed before the circuit unit 10 is fixed to the frame 12, preventing damage to the pre-charge resistor 22, etc.

[0104] Furthermore, the retaining portion 26 includes a flexible piece 132 with locking claws 134 at its protruding front end. With the pre-charge resistor 22 assembled in the retaining portion 26, each locking claw 134 abuts against the upper wall 86 of the metal housing 82, thereby preventing the pre-charge resistor 22 from being pulled upwards from the retaining portion 26. Therefore, before the circuit unit 10 is fixed to the frame 12, not only is left-right displacement suppressed as described above, but upward displacement is also suppressed, thus more reliably preventing damage to the pre-charge resistor 22.

[0105] Each fixing portion 16 in the pre-charge resistor 22 is positioned vertically at the same location as each held portion 94. The circuit unit 10 is fixed to the frame 12, and the fixed portion 42 in the frame 12 extends beyond the protruding end face 130 of the frame portion 122 and is positioned higher. In Embodiment 1, both the fixing portion 16 and the held portion 94 in the pre-charge resistor 22 are formed within the flange-like portions 90 in the metal housing 82. For example, compared to the case where the fixing portion and the held portion are separately provided, the pre-charge resistor 22 can be manufactured with a simpler structure, and thus the circuit unit 10 can be manufactured. Furthermore, each fixed portion 42 protrudes upward from the upper surface 32 of the frame 12, and a screw fastening hole 46 is provided at the upper end of each fixed portion 42. Therefore, the refrigerant flow path 34 can be formed in the frame 12 without considering the position of the screw fastening holes 46.

[0106] <Implementation Method 2>

[0107] Next, use Figures 10 to 16 The circuit unit 140 of Embodiment 2 of this disclosure will be described. The basic structure of the circuit unit 140 in Embodiment 2 is the same as that in Embodiment 1, and the structures of the main circuit 58 and the pre-charge circuit 68 are the same as in Embodiment 1. However, the way in which the pre-charge resistor 22 is held in the holding portion 142 before being fixed to the frame 12 differs from that in Embodiment 1. Hereinafter, the differences from Embodiment 1 will be mainly described. For components and parts that are the same as in Embodiment 1, the same reference numerals as in Embodiment 1 will be used in the figures, and detailed descriptions will be omitted.

[0108] <Shell 144>

[0109] In the circuit unit 140 of Embodiment 2, there is also a housing 144 for holding each relay 18a, 18b, pre-charge relay 20 and pre-charge resistor 22. The housing 144 is configured to include an upper housing 146 and a lower housing 148. The upper housing 146 and the lower housing 148 are fixed together and overlap each other.

[0110] <Upper shell 146>

[0111] The upper housing 146 has the same shape as the upper housing 98 in Embodiment 1, but in Embodiment 2, the upper housing 146 is provided with a displacement limiting rib 150 that is disposed opposite to the positioning wall portion 156 provided in the lower housing 148 (described later) to sandwich the heating element (pre-charging resistor 22). Specifically, the displacement limiting rib 150 is provided at the right end of the upper housing 146, to the right of each through hole 112, protruding downward from the upper bottom wall portion 102. In Embodiment 2, the displacement limiting rib 150 is integrally formed with respect to the upper housing 146 in a generally rectangular plate shape, has a predetermined length dimension (front-rear direction dimension) inside the upper housing 146, and protrudes to the vicinity of the lower opening of the upper housing 146. In particular, in Embodiment 2, reinforcing ribs 152 extending in a direction orthogonal to the length direction (left-right direction) are integrally formed at both ends of the displacement limiting rib 150 in the front-rear direction, thereby improving the deformation rigidity of the displacement limiting rib 150.

[0112] <Lower shell 148>

[0113] The lower housing 148 in Embodiment 2 also has the same shape as the lower housing 100 in Embodiment 1, and is also like... Figure 13 As shown, a bottom wall portion 114 is provided with openings 28 and 116 extending through the thickness direction (vertical direction). Furthermore, insertion holes 30 are formed at both ends of the openings 28 in the front-rear direction, communicating with the openings 28. A retaining portion 142, as described in Embodiment 2, is provided at the periphery of the openings 28.

[0114] <Maintenance Section 142>

[0115] As described above, the opening window 28 is rectangular in shape when viewed from above. The retaining portion 142 in Embodiment 2 includes protruding wall portions 154 that protrude towards the inside (i.e., upward) of the housing 144 from one of the pair of opposing pieces (opposing pieces in the front-to-back direction) respectively disposed on the opening window 28. Additionally, the retaining portion 142 includes a positioning wall portion 156 that protrudes towards the inside (i.e., upward) of one of the other pair of opposing pieces (opposing pieces in the left-to-right direction) disposed on the opening window 28 (the left side in Embodiment 2). The positioning wall portion 156 is a generally rectangular plate shape and has a front-to-back dimension approximately equal to that of the opening window 28. Furthermore, the retaining portion 142 includes the aforementioned displacement limiting rib 150 disposed on the upper housing 146.

[0116] Specifically, each protruding wall portion 154 is provided on both sides of the opening window 28 in the front-rear direction, that is, to the left of each insertion hole 30. In particular, in Embodiment 2, each protruding wall portion 154 is provided on the left and right sides of the rear insertion hole 30, and a total of three protruding wall portions 154 are provided on the lower housing 148. In addition, as described above, a positioning wall portion 156 is provided on the left side of the opening window 28, and the positioning wall portion 156 and each protruding wall portion 154 on both sides in the front-rear direction are connected by each bending portion 126 in the same way as in Embodiment 1. Therefore, in Embodiment 2, an insertion window portion 129 extending in the front-rear direction is formed between each of the rear protruding wall portions 154. Furthermore, while the pre-charge resistor 22 is held by the holding portion 142, each holding portion 94 of the pre-charge resistor 22 is mounted on the protruding end face 158 of each protruding wall portion 154.

[0117] Furthermore, in Embodiment 2, the upward protrusion dimension (vertical dimension from the upper surface of the bottom wall portion 114 to the protruding end face 158) C of each protruding wall portion 154 (refer to...) Figure 15 The upward protrusion dimension B of each fixed part 42 provided on the frame 12 is also smaller. Therefore, with the circuit unit 140 fixed to the frame 12, each fixed part 42 protrudes into the circuit unit 140 through each insertion hole 30 of the lower housing 148, and each fixed part 42 is disposed inside (above) the housing 144, passing over the protruding end face 158 of each protruding wall 154. In summary, with the circuit unit 140 fixed to the frame 12, the upper surface of each fixed part 42 is located above the protruding end face 158 of each protruding wall 154.

[0118] <Displacement Limiting Plate 162>

[0119] Furthermore, the retaining part 142 includes a displacement limiting piece 162, which extends from the protruding front end (upper end) of the positioning wall part 156 toward the heating element (pre-charging resistor 22), and is positioned inside (above) the housing 144, above the protruding end face 158 of each protruding wall part 154, and is positioned opposite the pre-charging resistor 22 with a gap 160 in the vertical direction. The displacement limiting piece 162 is generally rectangular in shape and has a predetermined left-right dimension and a front-back dimension. Thus, as... Figure 11 As shown, in the vertical projection, the upper surface 93a of the pre-charge resistor 22 overlaps with the displacement limiting piece 162.

[0120] Assembly of Circuit Unit 140

[0121] The following describes a specific example of the assembly method for circuit unit 140. It should be noted that the assembly method for circuit unit 140 is not limited to the method described below. Furthermore, in the assembly method for circuit unit 140, descriptions of parts with the same structure as in Embodiment 1 are omitted.

[0122] In Embodiment 2, the pre-charge resistor 22 is brought close from the right to the holding portion 142 of the lower housing 148 on which the relays 18a, 18b and the pre-charge relay 20 are fixed. Furthermore, the flange-like portions 90 of the metal housing 82 are mounted on the protruding end faces 158 of the protruding wall portions 154 constituting the holding portion 142, and the holding portion 142 holds the left and right ends of each flange-like portion 90. The approach of the pre-charge resistor 22 from the right to the holding portion 142 (displacement to the left) is limited, for example, by the contact between the left-side wall portion of the metal housing 82 and the positioning wall portion 156. In particular, in the holding portion 142, no protruding wall portion 154 is provided on the right side of the front insertion hole 30, thus allowing the pre-charge resistor 22, from which the wires 72, 74 extend forward, to approach the positioning wall portion 156 from the right.

[0123] Then, with the pre-charge resistor 22 held on the holding part 142, as follows: Figure 14 As shown, the upper housing 146 approaches from above, as Figure 15 , Figure 16 The upper housing 146 and the lower housing 148 are overlapped. As a result, the concave and convex shapes of the outer peripheral portions of the upper housing 146 and the lower housing 148 fit together, thus completing the circuit unit 140 of Embodiment 2.

[0124] That is, in the circuit unit 140 of Embodiment 2, the peripheral wall portion 84 of the heating element (pre-charge resistor 22) is disposed and positioned between the left-right opposing surfaces of the positioning wall portion 156 and the displacement limiting rib 150, and between the front-back opposing surfaces of a pair of protruding wall portions 154 facing each other in the front-back direction. Furthermore, in this state, as described above, the displacement limiting piece 162 is positioned above the pre-charge resistor 22 across the gap 160, preventing the pre-charge resistor 22, held by the holding portion 142, from being pulled upwards. Therefore, in the circuit unit 140, the pre-charge resistor 22 is surrounded by the displacement limiting rib 150, each protruding wall portion 154, the positioning wall portion 156, and the displacement limiting piece 162, and within them, the pre-charge resistor 22 can be displaced to a certain extent. As a result, during the assembly of the circuit unit 140, the pre-charge resistor 22 is temporarily assembled inside the circuit unit 140.

[0125] <Assembly of circuit unit 140 to the heat dissipation object (frame 12)>

[0126] The method for assembling the circuit unit 140 into the frame 12 is not limited, and the same method as in Embodiment 1 can be used. That is, the circuit unit 140 is overlapped on the upper surface 32 of the frame 12, and each fixed part 42 protruding upward from the upper surface 32 is inserted into the circuit unit 140 through each insertion hole 30 provided in the lower housing 148. As a result, the upper surface of each fixed part 42 abuts against each flange-like part 90 of each metal housing 82 from below, and these flange-like parts 90 (especially each retained part 94) separate upward from the protruding end face 158 of the retaining part 142 (especially each protruding wall part 154). Then, screws 44 are inserted into each screw insertion slot 92 through each insertion hole 112 in the upper housing 146 and tightened into each screw fastening hole 46. Thus, the assembly of the circuit unit 140 relative to the frame 12 is completed.

[0127] In the circuit unit 140 of Embodiment 2, which is configured as described above, only the insertion direction of the pre-charge resistor 22 relative to the holding part 142 is different from that of the circuit unit 10 of Embodiment 1, so it can achieve the same effect as Embodiment 1.

[0128] <Variation Example>

[0129] The above descriptions of embodiments 1 and 2 are specific examples of this disclosure, but this disclosure is not limited to these specific descriptions. Modifications and improvements within the scope of achieving the purpose of this disclosure are included in this disclosure. For example, the following modifications of the embodiments are also included in the technical scope of this disclosure.

[0130] (1) In the foregoing embodiment, the heat dissipation object is the battery pack frame 12, but it is not limited to this method. That is, the heat dissipation object can be any component that comes into thermal contact with the heat-generating component when the circuit unit of this disclosure is installed in a vehicle, such as a metal component that constitutes the vehicle body. It should be noted that the refrigerant flow path described in the foregoing embodiment may not be provided in the heat dissipation object.

[0131] (2) In the aforementioned embodiments, the heating component is composed of a pre-charge resistor 22, but it is not limited to this method. The heating component used in the circuit unit of this disclosure can be any component that heats up when energized, such as a relay, fuse, pre-charge relay, etc.

[0132] (3) In the aforementioned embodiments, the opening window 28 and each insertion hole 30 are interconnected in the bottom wall portion 114 of the lower housing 100, 148, but the opening window and the insertion hole can also be formed independently. In addition, the shape, size, number, etc. of the opening window and the insertion hole are not limited. The shape, size, number, etc. of the opening window can be appropriately set according to the heat-generating component, and the shape, size, number, etc. of the insertion hole can be appropriately set according to the fixed part provided on the heat dissipation object.

[0133] (4) In the above embodiments, the construction of the pre-charge resistor (metal-cased resistor) constituting the heating element is not limited as long as it has a metal casing. In the above embodiments, the wires 72 and 74 extending from the pre-charge resistor 22 extend from one end (front end) of the pre-charge resistor 22 in the longitudinal direction, but for example, in the case of the above embodiment 1, the two wires may also extend from both sides of the pre-charge resistor in the longitudinal direction.

[0134] (5) In the aforementioned embodiment, the pre-charge circuit 68 is connected in parallel with the positive side relay 18a, but the pre-charge circuit can also be connected in parallel with the negative side relay.

[0135] Explanation of reference numerals in the attached figures

[0136] 10 circuit units (Implementation Method 1)

[0137] 12. Frame (for heat dissipation)

[0138] 14 Thermal contact parts

[0139] 16 Fixing parts

[0140] 18 relays

[0141] 18a Positive Side Relay

[0142] 18b Negative-side relay

[0143] 20 Pre-charge relays

[0144] 22 Pre-charge resistor (heat-generating component)

[0145] 24 shell

[0146] 26 Maintaining Department

[0147] 28-opening window

[0148] 30 insertion holes

[0149] 32 Upper surface

[0150] 34 Refrigerant Flow Path

[0151] 36 Support section

[0152] 38 bolts

[0153] 40 bolt fastening hole

[0154] 42 Fixed Part

[0155] 44 screws

[0156] 46 screw fastening holes

[0157] 48 terminal section

[0158] 50 power supply busbar

[0159] Busbars for first to fourth power supply of 50a~50d

[0160] 52 bolts

[0161] 54a~54d connecting parts

[0162] 56 bolts

[0163] 58 main circuit

[0164] 60a~60d First~Fourth heat dissipation busbars

[0165] 62 heat dissipation section

[0166] 64 insulating sheet

[0167] 66 Elastic Thermal Conductive Components

[0168] 68 pre-charge circuit

[0169] 70, 72, 74 wires

[0170] 76 terminals

[0171] 78 screws

[0172] 80 terminal section

[0173] 82 Metal Casing

[0174] 84th perimeter wall

[0175] 86 Upper wall

[0176] 88 Lower wall

[0177] 90 flange-like portion

[0178] 92 screw through slot

[0179] 93a upper surface

[0180] 93b lower surface

[0181] 94 were kept in the department

[0182] 96 Elastic Thermal Conductive Components

[0183] 98 Upper Shell

[0184] 100 lower shell

[0185] 102 Upper bottom wall

[0186] 104 Last week's wall section

[0187] 106a~106d through window

[0188] 108 bolt through hole

[0189] 110 Installation Department

[0190] 112 Through Hole

[0191] 114 bottom wall

[0192] 116 Opening Window

[0193] 118 bolt through hole

[0194] 120 Installation Department

[0195] 121 lower surface

[0196] 122 frame section

[0197] 124 side wall section

[0198] 126 bends

[0199] 128 mounting section

[0200] 129 Insert Window

[0201] 130 protruding end face

[0202] 132 flexural plate

[0203] 134 Locking Claw

[0204] 136 inclined plane

[0205] 138 gap

[0206] 140 circuit units (Implementation Method 2)

[0207] 142 Maintenance Section

[0208] 144 housing

[0209] 146 Upper Shell

[0210] 148 Lower Housing

[0211] 150 displacement limiting rib

[0212] 152 Reinforcing Ribs

[0213] 154 protruding wall portion

[0214] 156 Positioning Wall

[0215] 158 protruding end face

[0216] 160 gap

[0217] 162 displacement limiting plate.

Claims

1. A circuit unit comprising: The heat-generating component has a heat-contact portion that is in thermal contact with a heat-dissipating object and a fixing portion that is fixed to the heat-dissipating object; The housing holds the heating element. A retaining part is provided protruding inside the housing to hold the heating element inside the housing; An opening window is provided through the housing, so that the thermal contact portion of the heating element is exposed to the outside of the housing; and An insertion hole is provided through the housing for insertion into the fixed part of the heat dissipation object. By fixing the fixing part of the heating element to the fixing part inserted into the insertion hole, the heating element is separated from the holding part, and the thermal contact part of the heating element is in thermal contact with the heat dissipation object.

2. The circuit unit according to claim 1, wherein, When fixed to the heat dissipation object, the thermal contact portion of the heat-generating component contacts the heat dissipation object via an elastic thermally conductive member.

3. The circuit unit according to claim 1 or 2, wherein, The retaining part includes a frame portion that surrounds the opening window and protrudes into the housing, and a retaining part that protrudes from the peripheral wall of the heating element is mounted on the protruding end face of the frame portion.

4. The circuit unit according to claim 3, wherein, The retaining portion includes a flexible plate portion that protrudes inward from the frame portion into the housing and is capable of flexing and deforming towards the outer periphery of the opening window. The flexible plate portion has a locking claw portion disposed at the protruding front end and protruding towards the inner peripheral side of the opening window. The assembly of the heating element to the frame portion is allowed by the flexible plate portion flexing and deforming towards the outer peripheral side. When the holding portion of the heating element is placed on the protruding end face of the frame portion, the locking claw portion of the elastically restored flexible plate portion overlaps with the heating element in the protruding direction of the frame portion with a gap.

5. The circuit unit according to claim 3, wherein, The fixing part of the heating element is positioned at the same location as the holding part in the protruding direction of the frame part. When fixed to the heat dissipation object, the fixed part of the heat dissipation object extends beyond the protruding end face in the protruding direction of the frame part and is disposed inside the housing.

6. The circuit unit according to claim 1 or 2, wherein, The housing includes a lower housing with the opening window and an upper housing overlapping the lower housing. The opening window has a rectangular shape. The retaining portion includes: a protruding wall portion, respectively disposed on one of a pair of opposing sides of the opening window and protruding into the housing; a positioning wall portion, disposed on one of the other pair of opposing sides of the opening window and protruding into the housing; and a displacement limiting rib, disposed on the upper housing and arranged opposite to the positioning wall portion in a manner that clamps the heating element in the middle. The heating element is configured and positioned between the opposing surfaces of the positioning wall and the displacement limiting rib, and between the opposing surfaces of the protruding wall. A retaining portion protruding from the peripheral wall of the heating element disposed between the protruding wall portions is placed on the protruding end face of the protruding wall portion.

7. The circuit unit according to claim 6, wherein, The retaining portion includes a displacement limiting piece that extends from the protruding front end of the positioning wall portion toward the heating element side, is positioned closer to the inner side of the housing than the protruding end face of the protruding wall portion, and is positioned opposite the heating element with a gap between them.

8. The circuit unit according to claim 6, wherein, The fixing part of the heating element is positioned at the same location as the holding part in the protruding direction of the protruding wall. When fixed to the heat dissipation object, the fixed part of the heat dissipation object extends beyond the protruding end face in the protruding direction of the protruding wall and is disposed inside the housing.

Images