Circuit unit in on-vehicle component

Abstract

To disclose a circuit unit in an on-vehicle component in which a structure for connecting an external connection part and a connector can be simplified and connection workability can be improved.SOLUTION: A circuit unit 10 in an on-vehicle component includes a circuit constituting member 16, a case 18, a connection bus bar 30 including an inner connection part 22 and an external connection part 28, a first window part 110 included in the case 18 so as to face the inner connection part 22 and a first bolt insertion hole 152, and a second wind part 112 included in the case 18 so as to face the external connection part 28 and a second bolt insertion hole 156. The first bolt insertion hole 152 and the second bolt insertion hole 156 are disposed so as to have sizes including tolerance absorbing gaps 154, 158. The connection bus bar 30 is housed in a displaceable manner in a tolerance absorbing direction with respect to the case 18. The first window part 110 is open in such a way that a bolt fastening work can be performed through the first window part 110. The second window part 112 is open in such a way that a bolt fastening work can be performed through the second window part 112.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a circuit unit in an on-vehicle component. [Background technology]

[0002] Patent Document 1 shows a structure in which a circuit unit such as a junction box is housed in a housing of a battery pack, which is an on-board component mounted in a vehicle, together with a battery module, a battery control system, etc. In this structure, in order to enable connection of the circuit unit housed in the housing of the battery pack with an external device, a connector to which an external mating connector is connected is provided on the peripheral wall of the housing, and a conductive connection is established between the connector and the circuit unit by relay parts such as coated wires and bus bars. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-243449 A Summary of the Invention [Problem to be solved by the invention]

[0004] The structure of Patent Document 1 requires relay parts such as coated electric wires and bus bars to connect between the connector provided in the housing and the external connection part provided in the circuit unit housed in the housing, which has the inherent problem of a large number of parts and poor handling. In addition, when the circuit unit is a junction box or the like housed in the housing of a high-voltage part such as a battery pack as in Patent Document 1, the relay parts and the external connection part of the circuit unit become live parts, so that separate measures against electric shock are required. As a result, the structure for connecting the external connection part of the circuit unit in the on-vehicle component to the connector provided in the housing of the on-vehicle component becomes complicated, and it is unavoidable that the workability decreases.

[0005] Therefore, the present invention discloses a circuit unit for an on-vehicle component that can simplify the connection structure between the external connection portion of the circuit unit for an on-vehicle component and a connector provided on the housing of the on-vehicle component and improve the ease of connection. [Means for solving the problem]

[0006] The circuit unit in an on-vehicle component of the present disclosure is a circuit unit housed in a housing of an on-vehicle component, and includes a circuit component member, an insulating case that houses the circuit component member, a connection bus bar housed in the case and having an internal connection portion that is conductively connected to a circuit side connection portion provided on the circuit component member and an external connection portion that is conductively connected to a connector side connection portion of a connector provided in the housing, a first window portion that is provided in the case and arranged to face the internal connection portion of the connection bus bar and a first bolt insertion hole provided in the internal connection portion, and a second window portion that is provided in the case and faces the external connection portion of the connection bus bar and a first bolt insertion hole provided in the internal connection portion. and a second window portion arranged opposite a second bolt insertion hole provided in a part connection portion, the first bolt insertion hole and the second bolt insertion hole are provided with a size that includes a tolerance absorption gap extending in a tolerance absorption direction, the connection bus bar is accommodated in the case so as to be displaceable in the tolerance absorption direction, the first window portion opens with a size that allows a bolt fastening operation to be performed from outside the case through the first window portion to the circuit side connection portion of the internal connection portion, and the second window portion opens with a size that allows a bolt fastening operation to be performed from outside the case through the second window portion to the connector side connection portion of the external connection portion. Effect of the Invention

[0007] According to the present disclosure, it is possible to provide a circuit unit in an on-board component that can simplify the connection structure between an external connection portion of the circuit unit in an on-board component and a connector provided on the housing of the on-board component and improve the ease of connection. [Brief description of the drawings]

[0008] [Figure 1]FIG. 1 is a perspective view showing a state in which a circuit unit in an on-vehicle component according to the first embodiment is housed in a housing of an on-vehicle component and bolts are fastened. [Diagram 2] FIG. 2 is an exploded perspective view showing a state in which a circuit unit in an on-vehicle component is accommodated in a housing of the on-vehicle component shown in FIG. 1 in an exploded state. [Diagram 3] FIG. 3 is an exploded perspective view showing the disassembled state of the circuit unit in the on-vehicle component shown in FIG. 2, as viewed from the front side. [Figure 4] FIG. 4 is an exploded perspective view showing the in-vehicle component circuit unit shown in FIG. 3 in an exploded state, as viewed from the rear side. [Diagram 5] FIG. 5 is a plan view showing the circuit unit housed in the housing of the on-vehicle component shown in FIG. 1, with the cover of the housing omitted. [Figure 6] FIG. 6 is a plan view showing the circuit unit in the on-board component shown in FIG. 5 with the cover portion omitted. [Figure 7] FIG. 7 is a plan view showing the circuit unit in the on-board component shown in FIG. 6 with the connection bus bars omitted. [Figure 8] FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. [Figure 9] FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. [Figure 10] FIG. 10 is a cross-sectional view taken along line XX in FIG. [Figure 11] FIG. 11 is an enlarged perspective view showing a cover portion constituting the in-vehicle component circuit unit shown in FIG. 1, viewed from the top side. [Figure 12] FIG. 12 is a perspective view showing the cover portion shown in FIG. 11 from the bottom side. [Figure 13] 13 is an enlarged perspective view of a main portion showing an enlarged fitting portion between a fitting hole and a fitting protrusion in the circuit unit in an on-board component shown in FIG. [Figure 14] FIG. 14 is an explanatory diagram for explaining the relationship between the first and second bolt insertion holes in the connection bus bar and the first and second bolts inserted into the first and second bolt insertion holes. [Figure 15]15 is a vertical cross-sectional view showing a state in which the circuit unit in the on-vehicle component shown in FIG. 1 is housed in a housing of the on-vehicle component with the bolts not fastened, and corresponds to FIG. [Figure 16] 16 is a vertical cross-sectional view showing a state in which the circuit unit in the on-vehicle component shown in FIG. 1 is housed in a housing of the on-vehicle component with the bolts not fastened, and corresponds to FIG. [Figure 17] FIG. 17 is a perspective view showing a connection bus bar constituting a circuit unit in an on-vehicle component according to another embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] <Description of the embodiments of the present disclosure> First, embodiments of the present disclosure will be listed and described. The circuit unit in the on-vehicle component according to the present disclosure includes: (1) A circuit unit in an on-vehicle component that is housed in a housing of an on-vehicle component, the circuit unit comprising: a circuit component member; an insulating case that houses the circuit component member; a connection bus bar that is housed in the case and has an internal connection portion that is conductively connected to a circuit side connection portion provided on the circuit component member; and an external connection portion that is conductively connected to a connector side connection portion of a connector provided in the housing; a first window portion that is provided in the case and arranged to face the internal connection portion of the connection bus bar and a first bolt insertion hole provided in the internal connection portion; and a second window portion arranged opposite a second bolt insertion hole formed in the case, the first bolt insertion hole and the second bolt insertion hole being provided with a size that includes a tolerance absorption gap extending in a tolerance absorption direction, the connection bus bar being accommodated in the case so as to be displaceable in the tolerance absorption direction, the first window portion being opened with a size that allows a bolt fastening operation to be performed from outside the case through the first window portion to the circuit side connection portion of the internal connection portion, and the second window portion being opened with a size that allows a bolt fastening operation to be performed from outside the case through the second window portion to the connector side connection portion of the external connection portion.

[0010] According to the circuit unit in the on-vehicle component of this embodiment, the connection bus bar that electrically connects the circuit-side connection part and the connector-side connection part is accommodated in the case in a state in which it can be displaced in the tolerance absorbing direction. Furthermore, the internal connection part and the external connection part of the connection bus bar accommodated in the case can be bolted to the circuit-side connection part and the connector-side connection part from the outside through the first window part and the second window part provided in the case. Therefore, the circuit unit is arranged in the housing of the on-vehicle component, and in a state in which the connection bus bar is displaced in the tolerance absorbing direction to absorb the tolerance, the internal connection part and the external connection part of the connection bus bar can be aligned with the circuit-side connection part and the connector-side connection part, respectively, and bolted from the outside. This eliminates the need for relay parts such as coated wires and bus bars that connect the connector provided in the housing and the external connection part provided in the circuit unit accommodated in the housing, which was previously necessary, and simplifies the connection structure between the circuit unit in the on-vehicle component and the connector provided in the housing of the on-vehicle component. Moreover, since the connection busbars are housed within the case, the case can be used to advantageously provide protection against electric shock. Furthermore, the first and second windows in the case only need to be large enough to allow bolt fastening of each connection from the outside, so that the case can cover as many areas as possible that may become live, improving the ease of connection work.

[0011] The tolerance absorption direction can be set to a required direction, and may be one direction or multiple directions. Also, the first and second windows need only open large enough to allow bolt tightening of each connection from outside the case, and if no bolts or nuts are built into the case, they need only be large enough to allow the bolts and nuts to be inserted therethrough, and if bolts and nuts are built into the case, they need only be large enough to allow the fastening tool to be inserted therethrough while preventing the bolts and nuts from coming off the window.

[0012] (2) It is preferable that the first window portion and the second window portion are each surrounded by a cylindrical portion protruding outward from the case. Since the first window portion and the second window portion are surrounded by a cylindrical portion protruding outward from the case, by adjusting the protruding height of the cylindrical portion, it is possible to advantageously prevent an operator from coming into contact with an internal connection portion or an external connection portion that may become a live part.

[0013] (3) It is preferable that a bolt or a nut is accommodated inside each of the cylindrical portions of the first window portion and the second window portion, a protruding tip side of the cylindrical portion is provided with a radially inwardly protruding anti-removal protrusion, and the bolt or the nut is prevented from coming off from the cylindrical portion by abutting against the anti-removal protrusion. The bolt or nut for fastening the internal connection portion and the external connection portion of the connection busbar to the circuit side connection portion and the connector side connection portion can be built in the case in advance by utilizing the internal space of each cylindrical portion of the first window portion and the second window portion, thereby further improving workability. In addition, since the bolt or nut is previously accommodated in each cylindrical portion of the first window portion and the second window portion, the size of the opening of the first window portion and the second window portion can be reduced to a size that does not allow the bolt or nut to be inserted but allows the insertion of a fastening tool, thereby further improving the electric shock countermeasure. In particular, the electric shock countermeasure can be further strengthened by insulating the exposed portion of the built-in bolt or nut from the window portion.

[0014] (4) It is preferable that the bolt or nut housed in each of the cylindrical portions has an insulating processing portion, and the insulating processing portion of the bolt or nut can protrude from the cylindrical portion in an unfastened state and is housed in the cylindrical portion in a fastened state. Since the bolt or nut housed in each cylindrical portion has an insulating processing portion, electric shock through a fastening tool is prevented during fastening work. In particular, when the insulating processing portion protrudes from the cylindrical portion in an unfastened state of the bolt or nut, it is easy to visually confirm that the bolt or nut is in an unfastened state, and fastening work can be easily performed. Moreover, since the protruding portion is an insulating processing portion, measures against electric shock can be maintained. Furthermore, since the insulating processing portion is housed in the cylindrical portion in a fastened state, it is easy to confirm from the outside that the bolt or nut is in a fastened state, and further, even in a finished product in which fastening is completed, the protruding height of the cylindrical portion to the outside of the case can be kept small, and the circuit unit in the vehicle-mounted component can be made smaller.

[0015] (5) It is preferable that the case has a case main body having a mounting portion on which the connection busbar is placed, and a cover portion that covers the mounting portion and is assembled to be displaceable in the tolerance absorbing direction relative to the case main body, and the cover portion has the first window portion and the second window portion and displaces together with the connection busbar in the tolerance absorbing direction. Since the case is divided into a case main body having a mounting portion on which the connection busbar is placed, and a cover portion that covers the mounting portion and is assembled to be displaceable in the tolerance absorbing direction relative to the case main body, and the cover portion displaces together with the connection busbar, a structure that accommodates the connection busbar so as to be displaceable in the tolerance absorbing direction relative to the case can be simply and reliably provided. Moreover, since the cover portion, which is a part of the case, displaces together with the connection busbar, the opening size of the first window portion and the second window portion can be made smaller than when only the connection busbar displaces relative to the case, and safer measures against electric shock can be taken.

[0016] (6) It is preferable that the case body has a fitting hole extending in the tolerance absorption direction around the placement portion, the cover part has a fitting protrusion protruding from a peripheral portion of the cover part toward the case body and fitting into the fitting hole, and the width dimension of the fitting protrusion in the tolerance absorption direction is smaller than that of the fitting hole. By making the width dimension of the fitting protrusion of the cover part that fits into the fitting hole provided in the case body smaller in the tolerance absorption direction than the width dimension of the fitting hole in the tolerance absorption direction, the fitting protrusion can be displaced in the tolerance absorption direction within the fitting hole. As a result, the cover part having the fitting protrusion can be displaced in the tolerance absorption direction relative to the case body, and the moving end of the cover part (connection bus bar) relative to the case body in the tolerance absorption direction can be determined by using the fitting protrusion and the fitting hole that assemble the cover part to the case body.

[0017] (7) It is preferable that the fitting protrusion has a lock claw provided at a protruding end and protruding toward the mounting portion side from the fitting hole, and the lock claw inserted into the fitting hole engages with an edge of the fitting hole on the mounting portion side. Since the lock claw protrudes toward the mounting portion side from the fitting hole and engages with an edge of the fitting hole on the mounting portion side, it is difficult to insert a tool such as a screwdriver into the fitting hole so as to deflect the fitting protrusion in a direction in which the engagement between the lock claw and the case body is released, and the engagement between the lock claw and the case body is stably maintained. In addition, the engagement portion between the lock claw and the case body cannot be visually confirmed from the outside, and the engagement between the lock claw and the case body is more reliably prevented from being released. As a result, the cover part can be held in a fixed state relative to the case body. As a result, the risk of an operator accidentally removing the cover part from the case during maintenance and receiving an electric shock can be reduced.

[0018] (8) It is preferable that the internal connection portion and the external connection portion are expanded in mutually intersecting directions, the first bolt insertion hole provided in the internal connection portion and the second bolt insertion hole provided in the external connection portion penetrate in mutually intersecting directions, and the tolerance absorption direction in the tolerance absorbing gap of the first bolt insertion hole and the tolerance absorption direction in the tolerance absorbing gap of the second bolt insertion hole are mutually orthogonal directions. Since the internal connection portion and the external connection portion are expanded in mutually intersecting directions, the first bolt insertion hole and the second bolt insertion hole provided in the internal connection portion and the external connection portion, respectively, are arranged to intersect with each other. Therefore, the tolerance absorption direction in the tolerance absorbing gap of the first bolt insertion hole and the tolerance absorption direction in the tolerance absorbing gap of the second bolt insertion hole can be set to mutually orthogonal directions, and the connection bus bar can be displaced with respect to the case in at least two mutually orthogonal directions. This allows the circuit component conductively connected to the internal connection part and the connector conductively connected to the external connection part to be stably connected by the connection bus bar. Note that, for example, by setting the tolerance absorbing direction in the tolerance absorbing gap of the first bolt insertion hole to two mutually perpendicular directions (e.g., front-to-back and left-to-right directions) and the tolerance absorbing direction in the tolerance absorbing gap of the second bolt insertion hole to a direction perpendicular to those directions (e.g., up-down direction), the connection bus bar can be displaced in each of the up-down, left-to-right, and front-to-back directions relative to the case, and the circuit component and the connector can be more reliably connected via the connection bus bar.

[0019] (9) It is preferable that the cover portion has a rib protruding toward the mounting portion, and the rib abuts or faces the connection bus bar when the cover portion is assembled to the case body. The rib protruding toward the mounting portion provided on the cover portion abuts the connection bus bar or faces the connection bus bar with a small gap when the cover portion is assembled to the case body. This prevents the connection bus bar from floating up when the connection bus bar is displaced from the mounting portion of the case body by the rib. Therefore, the connection bus bar is prevented from rattling inside the case. In particular, when the connection bus bar is connected to a heat generating component such as a relay via a circuit component or the like, the circuit component may have a heat dissipation portion that contacts a heat transfer surface provided on the case body. In such a case, by providing a rib on the cover portion to prevent the connection bus bar from floating up, it is possible to prevent not only the connection bus bar but also the circuit component provided with the heat dissipation portion from floating up, and advantageously prevent the heat dissipation portion from floating up from the heat transfer surface toward the cover portion. This also makes it possible to stably maintain heat dissipation from the heat-generating components via the connection bus bars.

[0020] (10) It is preferable that the connection busbar has a first end provided with the internal connection portion and a second end provided with the external connection portion and protruding upward from the first end, the internal connection portion includes the first bolt insertion hole having the tolerance absorbing gap in the extending direction of the first end, and the external connection portion includes the second bolt insertion hole having the tolerance absorbing gap in the extending direction of the second end. The second end of the connection busbar is provided with the external connection portion protruding upward from the first end provided with the internal connection portion, and the first bolt insertion hole and the second bolt insertion hole have the tolerance absorbing gap in the mutually different extending directions of the first end and the second end. This makes it possible to set the tolerance absorbing direction in a plurality of directions, and further improves the workability of assembling the circuit unit in the on-vehicle component to the on-vehicle component. In particular, since the second end protrudes upward from the first end, a space for accommodating a component such as a wire harness can be provided in the space between them.

[0021] (11) It is preferable that the connection busbar is a laminate of a plurality of thin plates. When the connection busbar is a laminate of a plurality of thin plates, the connection busbar can be deformed flexibly. As a result, even when the length dimension of the connection busbar is short and a single flat busbar has a large deformation rigidity, the connection busbar can be deformed to absorb the tolerance, and the circuit-side connection portion provided on the circuit component and the connector-side connection portion provided on the connector can be more reliably connected.

[0022] <Details of the embodiment of the present disclosure> Specific examples of the circuit unit in an on-vehicle component of the present disclosure will be described below with reference to the drawings. Note that the present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0023] <Embodiment 1> Hereinafter, a first embodiment of the present disclosure will be described with reference to Figs. 1 to 16. The circuit unit 10 is mounted on a vehicle (not shown), such as an electric vehicle or a hybrid vehicle, and supplies and controls power from a power source such as a battery (not shown) to a load such as a motor (not shown). In Fig. 1 and other figures, the circuit unit 10 is shown housed in a housing 14 of a battery pack 12 as an on-vehicle component, and fastened by first and second bolts 138, 140 (described later). The circuit unit 10 and the on-vehicle component (battery pack 12 (housing 14)) are not shown in their entirety, but are shown by extracting essential parts. The circuit unit 10 can be arranged in any direction, but in the following description, the upper side refers to the upper side in Fig. 8, the lower side refers to the lower side in Fig. 8, the front side refers to the right side in Fig. 5, the rear side refers to the left side in Fig. 5, the left side refers to the lower side in Fig. 5, and the right side refers to the upper side in Fig. 5. In addition, in the case of multiple identical components, reference numerals may be given to only some of the components and the reference numerals may be omitted for the other components.

[0024] <In-vehicle component circuit unit 10> The in-vehicle component circuit unit 10 is housed in a housing 14 of the in-vehicle component (battery pack 12), and includes a circuit component 16 and an insulating case 18 that houses the circuit component 16. The case 18 houses a connection bus bar 30 (first connection bus bar 30a and second connection bus bar 30b) having an internal connection portion 22 (first internal connection portion 22a and second internal connection portion 22b) that is conductively connected to a circuit side connection portion 20 (first circuit side connection portion 20a and second circuit side connection portion 20b) provided on the circuit component 16, and an external connection portion 28 (first external connection portion 28a and second external connection portion 28b) that is conductively connected to a connector side connection portion 26 (first connector side connection portion 26a and second connector side connection portion 26b) of a connector 24 provided in the housing 14.

[0025] <Battery pack 12> Although the on-vehicle component in which the circuit unit 10 is housed is not limited, in this embodiment, the on-vehicle component is a battery pack 12. The housing 14 of the battery pack 12 includes a housing main body 32 and a lid 34, as shown in Fig. 2. The housing main body 32 is, for example, substantially box-shaped with an upward opening, and includes a bottom wall 36 and a peripheral wall portion 38 protruding upward from the outer periphery of the bottom wall 36. Note that Fig. 2 and other figures show the essential parts of the battery pack 12 (housing 14) in an extracted state, and only a rear wall portion 40 is shown as the peripheral wall portion 38, but walls constituting the peripheral wall portion 38 may be provided in front of the bottom wall 36 or on both the left and right sides.

[0026] The rear wall 40 is provided with a connector insertion hole 42 for inserting the connector side connection portion 26 (the connector side connection portions 26a, 26b) of the connector 24 into the housing 14. The connector side connection portion 26 (the connector side connection portions 26a, 26b) is inserted into the housing main body 32 through the connector insertion hole 42, and the connector 24 is fastened to the housing main body 32 with bolts 44, thereby attaching the connector 24 to the housing 14. Then, the in-vehicle component circuit unit 10 is placed in the housing main body 32 and electrically connected to the connector 24, and then the upper opening of the housing main body 32 is covered and fixed with a cover 34 having a substantially flat plate shape, thereby storing the in-vehicle component circuit unit 10 in the housing 14.

[0027] <Connector 24> Although the shape of the connector 24 is not limited, in this embodiment, the connector 24 includes a pair of electric wires 46, 46. Each electric wire 46 is a coated electric wire and includes a core wire 48 and an insulating coating 50 that is inserted around the core wire 48. At the end (front end) of each electric wire 46, the insulating coating 50 is stripped off to expose the core wire 48. The core wire 48 exposed by stripping off the insulating coating 50 is electrically connected to a connector terminal 54 in a connector housing 52 made of insulating synthetic resin or the like. That is, the connector 24 includes a pair of connector terminals 54, 54 by providing the connector terminal 54 at the end of each electric wire 46, and the pair of connector terminals 54, 54 are arranged side by side in the left-right direction.

[0028] Each connector terminal 54 has a bolt fastening hole at its front end, and in this embodiment, these bolt fastening holes form the first and second connector side connection parts 26a, 26b. In short, the connection bus bar 30 in the on-board component circuit unit 10 is electrically connected to the connector 24 by inserting second bolts 140, 140 described later into the external connection parts 28 (first and second external connection parts 28a, 28b) of the connection bus bar 30 in the on-board component circuit unit 10 and fastening them to the bolt fastening holes (first and second connector side connection parts 26a, 26b) of the connector terminals 54 in the connector 24.

[0029] The connector housing 52 is fixed to the housing body 32 via an attachment portion 56 having a predetermined thickness. That is, the attachment portion 56 has insertion holes through which the connector side connecting portions 26a, 26b and the bolts 44, 44 of the connector 24 are inserted. When the connector 24 is fixed to the housing body 32 with the bolts 44, the connector side connecting portions 26a, 26b pass through the attachment portion 56 and are exposed inside the housing body 32 through the connector insertion holes 42 in the rear wall portion 40.

[0030] <Circuit component 16> 3 and 4, in this embodiment, the circuit component 16 includes a pair of relays (a first relay 58a and a second relay 58b) and a conduction bus bar 62 (first to fourth conduction bus bars 62a to 62d) connected to a pair of connection parts 60, 60 provided on each of the relays 58a, 58b. In this embodiment, the first relay 58a and the second relay 58b are arranged facing opposite to each other, with the first relay 58a on the left facing backward and the second relay 58b on the right facing forward.

[0031] A first conduction bus bar 62a is connected to the left connection portion 60 of the first relay 58a, and the first conduction bus bar 62a is electrically connected to an external circuit (not shown) on the left side of the in-vehicle component circuit unit 10. A second conduction bus bar 62b is connected to the right connection portion 60 of the first relay 58a. The end of the second conduction bus bar 62b opposite to the side connected to the first relay 58a protrudes upward beyond the first relay 58a via a lower heat dissipation portion 64 (second heat dissipation portion 64b) described later, and constitutes the first circuit side connection portion 20a. In particular, the first circuit side connection portion 20a is constituted by a bolt insertion hole that penetrates in the plate thickness direction (up and down direction) and is provided at the end of the second conduction bus bar 62b opposite to the side connected to the first relay 58a.

[0032] Furthermore, a third conduction bus bar 62c is connected to the left connection portion 60 of the second relay 58b. In the third conduction bus bar 62c, the end opposite to the side connected to the second relay 58b protrudes upward from the second relay 58b via a lower heat dissipation portion 64 (third heat dissipation portion 64c) described later, and constitutes the second circuit side connection portion 20b. In particular, the second circuit side connection portion 20b is constituted by a bolt insertion hole that penetrates in the plate thickness direction (up and down direction) provided at the end opposite to the side connected to the second relay 58b in the third conduction bus bar 62c. Furthermore, a fourth conduction bus bar 62d is connected to the right connection portion 60 of the second relay 58b, and this fourth conduction bus bar 62d is electrically connected to an external circuit (not shown) to the right of the in-vehicle component circuit unit 10.

[0033] Each of the conduction busbars 62 (the first to fourth conduction busbars 62a to 62d) is made of a metal plate having electrical conductivity, and is formed by bending the metal plate into a predetermined shape by pressing or the like. Each of the first to fourth conduction busbars 62a to 62d has a portion extending horizontally (perpendicular to the up-down direction) at the bottom, and the portion extending horizontally at the bottom is a heat dissipation portion 64 (the first to fourth heat dissipation portions 64a to 64d). As described later, the first and second connection busbars 30a and 30b are connected to the second and third conduction busbars 62b and 62c. Therefore, the first and second connection busbars 30a and 30b indirectly have a heat dissipation portion 64 (the second and third heat dissipation portions 64b and 64c) via the second and third conduction busbars 62b and 62c.

[0034] <Case 18> The case 18 has a case body 68 having a mounting portion 66 on which the connection bus bar 30 is placed, and a cover portion 70 that covers the mounting portion 66 and is attached to the case body 68 .

[0035] <Case body 68> The case body 68 has an upper case 72 and a lower case 74 that are assembled in the vertical direction. The upper case 72 and the lower case 74 are box-shaped and open downward and upward, respectively, and are made of, for example, hard synthetic resin. That is, the upper case 72 has an upper wall 76 that is generally rectangular, and an upper peripheral wall 78 that protrudes downward from the outer periphery of the upper wall 76. Also, a rear end wall portion 79 that protrudes upward is provided on the right side of the rear end portion of the upper wall 76. Note that, in Figs. 3 and 4, etc., the main portion of the in-vehicle component circuit unit 10 is shown in an extracted state, and only an upper front wall 80 and an upper rear wall 82 are shown as the upper peripheral wall 78, but walls that constitute the upper peripheral wall 78 may be provided on both the left and right sides of the upper wall 76.

[0036] As shown in FIG. 7, the upper wall 76 is provided with a substantially rectangular through window 84 penetrating in the plate thickness direction (vertical direction). In this embodiment, the upper wall 76 is provided with two through windows 84 (a first through window 84a and a second through window 84b). The first through window 84a and the second through window 84b are provided at positions corresponding to the first circuit side connection portion 20a of the second conduction bus bar 62b and the second circuit side connection portion 20b of the third conduction bus bar 62c, respectively. Specifically, the first through window 84a is provided in the substantially central portion of the upper wall 76, and the second through window 84b is provided in the right rear portion of the upper wall 76. As a result, when the circuit component 16 is housed in the case body 68, the first circuit side connection portion 20a and the second circuit side connection portion 20b are exposed to the outside through the first through window 84a and the second through window 84b.

[0037] As described below, the connection busbar 30 (the first connection busbar 30a and the second connection busbar 30b) is overlapped from above with the first circuit-side connecting portion 20a and the second circuit-side connecting portion 20b exposed from the first through window 84a and the second through window 84b. The area of ​​the upper wall 76 where the first connection busbar 30a and the second connection busbar 30b are overlapped and placed is the placement portion 66. In this embodiment, the placement portion 66 is configured to include the area in the upper wall 76 from the first through window 84a to the second through window 84b, for example, the area from the rear portion of the first through window 84a to the left portion of the second through window 84b.

[0038] Moreover, fitting holes 86 penetrating the upper wall 76 in the plate thickness direction are provided around the mounting portion 66. The fitting holes 86 are adapted to fit with fitting protrusions 132 (described later) provided on the cover portion 70. In this embodiment, a plurality of fitting holes 86 are provided, with three fitting holes 86 provided around the first through window 84a and one fitting hole 86 provided around the second through window 84b. Each fitting hole 86 has a substantially rectangular shape extending in the front-rear direction, which is one of the tolerance absorption directions (described later), and an opening width dimension b in the front-rear direction (see FIG. 7) is larger than an opening width dimension a in the left-right direction (see FIG. 7).

[0039] The lower case 74 has a bottom wall 88 that is generally rectangular overall, and a bottom peripheral wall 90 that protrudes upward from the outer periphery of the bottom wall 88. Note that in Figures 3 and 4 and the like, the essential parts of the circuit unit 10 are extracted and only a bottom front wall 92 and a bottom rear wall 94 are shown as the bottom peripheral wall 90, but walls that constitute the bottom peripheral wall 90 may be provided on both the left and right sides of the bottom wall 88.

[0040] 3 and 4, the lower wall 88 is provided with a busbar fixing portion 96 having a generally rectangular columnar shape that protrudes upward. In this embodiment, the busbar fixing portions 96 (a first busbar fixing portion 96a and a second busbar fixing portion 96b) are provided at two locations on the lower wall 88. The first busbar fixing portion 96a and the second busbar fixing portion 96b are provided at positions corresponding to the first circuit side connecting portion 20a of the second conduction busbar 62b and the second circuit side connecting portion 20b of the third conduction busbar 62c, respectively. Specifically, the first busbar fixing portion 96a is provided in a generally central portion of the lower wall 88, and the second busbar fixing portion 96b is provided in a right rear portion of the lower wall 88. Nuts 98 are embedded in the upper end portions of the first and second busbar fixing portions 96a, 96b.

[0041] When the circuit components 16 are housed in the case body 68, the heat dissipation sections 64 (first to fourth heat dissipation sections 64a to 64d) of the conductive bus bars 62 (first to fourth conductive bus bars 62a to 62d) are overlapped with a bottom wall 88 of the lower case 74. Between each of the heat dissipation sections 64a to 64d and the bottom wall 88, a substantially sheet-like heat transfer sheet 100 made of a material with relatively good heat transfer efficiency is provided, and each of the heat dissipation sections 64a to 64d is in contact with the bottom wall 88 via the heat transfer sheet 100. As described later, the bottom wall 88 of the case body 68 is overlapped with a bottom wall 36 of the housing 14 of the battery pack 12. Between the lower wall 88 and the bottom wall 36, gap fillers 102 made of a material having a relatively good heat transfer efficiency are provided at positions corresponding to the heat transfer sheets 100, and the lower wall 88 is adapted to be in contact with the bottom wall 36 via the gap fillers 102. That is, heat generated with the passage of electricity through the relays 58a, 58b is dissipated from the bottom wall 36 via the heat dissipation sections 64a to 64d, the heat transfer sheets 100, the lower wall 88, and the gap fillers 102. Therefore, in this embodiment, a heat transfer surface 104 that is provided on the case main body 68 and contacts the heat dissipation sections 64a to 64d to transfer heat generated with the passage of electricity through the relays 58a, 58b is formed by the upper surface of the lower wall 88.

[0042] The material of the heat transfer sheet 100 and the gap filler 102 is not limited as long as it has insulating properties, and may be made of, for example, synthetic resin having a higher thermal conductivity than air. Specifically, silicone resin, non-silicone acrylic resin, ceramic resin, etc. can be used. More specifically, for example, a heat dissipation sheet or heat dissipation gap filler made of silicone resin, heat conductive grease, heat conductive silicone rubber, etc. can be used. Note that the heat transfer member provided between each of the heat dissipation parts 64a to 64d and the lower wall 88 is not limited to a sheet shape, and a conventionally known heat transfer member can be used. Also, in Figs. 3 and 4, the gap filler 102 is shown in a substantially rectangular block shape, but the shape of the gap filler 102 is not limited, and a conventionally known gap filler (heat transfer member) can be used.

[0043] In particular, the heat transfer sheet 100 and the gap filler 102 are elastically deformable in the thickness direction (vertical direction), and the elastic deformation of the heat transfer sheet 100 and the gap filler 102 in the vertical direction can also absorb the vertical tolerance between the circuit unit 10 in the vehicle-mounted component and the housing 14 of the battery pack 12 when the second bolts 140 are used to fasten the external connection portions 28a, 28b and the connector side connection portions 26a, 26b.

[0044] <Cover part 70> The cover portion 70 has a shape that covers the placement portion 66 of the case main body 68, and has a shape that extends from the first through window 84a to the second through window 84b of the upper case 72. That is, as shown in Figs. 11 and 12, the cover portion 70 has a horizontal wall portion 106 that extends in the left-right direction and spreads in a substantially horizontal direction (a direction perpendicular to the up-down direction). In addition, a vertical wall portion 108 that protrudes upward and spreads in the up-down direction is provided on the right side of the rear end portion of the horizontal wall portion 106. As a result, the cover portion 70 has a substantially L-shaped vertical cross section on the right side.

[0045] In addition, the horizontal wall 106 of the cover 70 is provided with a first window 110 penetrating in the plate thickness direction (up-down direction) at a position corresponding to the through window 84 and the circuit side connection portion 20 exposed from the through window 84 when the cover 70 is assembled to the case body 68. In this embodiment, the horizontal wall 106 is provided with a left first window 110a and a right first window 110b at positions corresponding to the first and second circuit side connection portions 20a, 20b, respectively. Furthermore, the vertical wall 108 is provided with a second window 112 penetrating in the plate thickness direction (front-rear direction) at a position corresponding to the connector side connection portion 26 when the in-vehicle component circuit unit 10 is housed in the housing 14 of the battery pack 12. In this embodiment, the vertical wall 108 is provided with a left second window 112a and a right second window 112b at positions corresponding to the first and second connector side connection portions 26a, 26b, respectively.

[0046] As described later, the first and second circuit-side connection portions 20a, 20b are overlapped and conductively connected to the internal connection portions 22 (first and second internal connection portions 22a, 22b) of the connection bus bars 30a, 30b, and therefore the left and right first window portions 110a, 110b are provided at positions corresponding to the first and second internal connection portions 22a, 22b. That is, in an assembled state of the in-vehicle component circuit unit 10, the left and right first window portions 110a, 110b are disposed to face each of the internal connection portions 22a, 22b and the first bolt insertion holes 152 provided in each of the internal connection portions 22a, 22b in the up-down direction. In addition, since the first and second connector side connection portions 26a, 26b are overlapped and conductively connected to the external connection portions 28 (first and second external connection portions 28a, 28b) of the respective connection bus bars 30a, 30b, the left and right second window portions 112a, 112b are provided at positions corresponding to the first and second external connection portions 28a, 28b. That is, in an assembled state of the in-vehicle component circuit unit 10, the left and right second window portions 112a, 112b are disposed to face, in the front-rear direction, the respective external connection portions 28a, 28b and the second bolt insertion holes 156 provided in the respective external connection portions 28a, 28b.

[0047] In this embodiment, the left and right first window portions 110a, 110b and the second window portions 112a, 112b are formed in the same shape, and are formed as circular through holes having a predetermined inner diameter dimension φA (see FIG. 8). The inner diameter dimension φA of the left and right first window portions 110a, 110b may be large enough to allow a tool for bolt fastening work of the internal connection portions 22a, 22b and the circuit side connection portions 20a, 20b by the first bolts 138 described later to be inserted from the outside of the case 18. In this embodiment, the inner diameter dimension φA of the left and right first window portions 110a, 110b is larger than the maximum outer diameter dimension φC (see FIG. 14) of the head portion 144 including the insulation processing portion 146 of each first bolt 138 described later. Similarly, the inner diameter dimension φA of the left and right second windows 112a, 112b need only be large enough to allow insertion of a tool for bolt fastening work using second bolts 140, described below, between each of the external connection portions 28a, 28b and each of the connector side connection portions 26a, 26b from the outside of the case 18. In this embodiment, the inner diameter dimension φA of the left and right second windows 112a, 112b is made larger than the maximum outer diameter dimension φC of a head 144 including an insulation processing portion 146 of each of the second bolts 140, described below.

[0048] Furthermore, first cylindrical portions 114, 114 as cylindrical portions protruding upward are provided from the peripheries of the left and right first window portions 110a, 110b in the horizontal wall portion 106, and second cylindrical portions 116, 116 as cylindrical portions protruding forward are provided from the peripheries of the left and right second window portions 112a, 112b in the vertical wall portion 108. That is, both of these first and second cylindrical portions 114, 116 protrude outward from the cover portion 70 and the case 18 to which the cover portion 70 is assembled.

[0049] Each of the first and second cylindrical portions 114, 116 has a predetermined protruding height. A retaining protrusion 118 that protrudes radially inward is provided on the protruding tip side of each of the first and second cylindrical portions 114, 116. In this embodiment, the retaining protrusion 118 is formed in a ring shape over the entire circumference in the circumferential direction at the protruding tip of each of the first and second cylindrical portions 114, 116. As a result, the outer opening 120 of each of the first and second cylindrical portions 114, 116 has a predetermined inner diameter, and the inner diameter dimension (inner diameter dimension of the retaining protrusion 118) φA' (see FIG. 8) of the outer opening 120 of each of the first and second cylindrical portions 114, 116 in the first and second cylindrical portions 114, 116 is smaller than the inner diameter dimension φA of each of the first windows 110a, 110b.

[0050] Furthermore, a lower protective wall portion 122 protruding downward is provided on the outer peripheral edge of the horizontal wall portion 106, and a rear protective wall portion 124 protruding rearward is provided on the outer peripheral edge of the vertical wall portion 108. The lower protective wall portion 122 and the rear protective wall portion 124 are formed continuously over substantially the entire circumference of the horizontal wall portion 106 and the vertical wall portion 108, and are formed continuously and integrally at the connection portion of the horizontal wall portion 106 and the vertical wall portion 108. Furthermore, a partition wall portion 126 is provided on the lower surface of the horizontal wall portion 106 and the rear surface of the vertical wall portion 108, which divides the area surrounded by the lower protective wall portion 122 and the rear protective wall portion 124 into two. That is, the partition wall portion 126 is substantially L-shaped and extends across the horizontal wall portion 106 and the vertical wall portion 108. Of the two areas separated by partition wall portion 126, the left area is a first accommodating area 128a in which the first connection busbar 30a is accommodated, and the right area is a second accommodating area 128b in which the second connection busbar 30b is accommodated.

[0051] In Fig. 12, the first and second connection bus bars 30a, 30b accommodated in the first and second accommodation areas 128a, 128b are indicated by two-dot chain lines. As shown in Fig. 12, the connection bus bars 30a, 30b face the walls 122, 124, 126 constituting the accommodation areas 128a, 128b with a small gap in the front-rear and left-right directions, and the connection bus bars 30a, 30b can be slightly displaced in the left-right direction within the accommodation areas 128a, 128b. Note that a vertical portion 150 (to be described later) of each connection bus bar 30a, 30b is sandwiched between a vertical wall portion 108 (a rib 130 (to be described later)) of the cover portion 70 and a rear end wall portion 79 of the upper case 72 in the front-rear direction, so that the connection bus bars 30a, 30b are substantially unable to be displaced in the front-rear direction within the accommodation areas 128a, 128b. As described below, the cover portion 70 is capable of being displaced in the front-to-rear direction relative to the case main body 68 (upper case 72), and therefore each connecting bus bar 30a, 30b is capable of being displaced in the front-to-rear direction together with the cover portion 70 relative to the case main body 68 (upper case 72).

[0052] Furthermore, on the lower surface of the horizontal wall portion 106 and the rear surface of the vertical wall portion 108, ribs 130 are provided inside the area surrounded by the lower protective wall portion 122 and the rear protective wall portion 124, protruding toward the placement portion 66 and the rear end wall portion 79, respectively. That is, the ribs 130 are provided in both the first storage area 128a and the second storage area 128b separated by the partition wall portion 126. In this embodiment, a plurality of ribs 130 are provided, each formed as a protrusion extending in the front-rear direction or the left-right direction. The plurality of ribs 130 form a lattice shape as a whole and are formed integrally.

[0053] When the cover portion 70 is assembled to the upper case 72 with the connection bus bars 30a, 30b accommodated in the first and second accommodation regions 128a, 128b, the ribs 130 are slightly compressed between the horizontal wall portion 106 and the vertical wall portion 108 and the connection bus bars 30a, 30b, or the ribs 130 and the connection bus bars 30a, 30b are in zero-touch contact with each other, or the ribs 130 and the connection bus bars 30a, 30b face each other with a slight separation distance between them. In other words, when the ribs 130 are compressed, the connection bus bars 30a, 30b are pressed from above and from the front against the top wall 76 (mounting portion 66) and rear end wall portion 79 of the upper case 72 by the elastic restoring force of the ribs 130. During assembly of the in-vehicle component circuit unit 10, the ribs 130 prevent the connection busbars 30a, 30b from lifting up from the mounting portion 66, thereby restricting the upward displacement of the second and third conduction busbars 62b, 62c that contact the connection busbars 30a, 30b from below. This allows the second and third heat dissipation portions 64b, 64c of the second and third conduction busbars 62b, 62c to more reliably contact the heat transfer surface 104 of the bottom wall 88 of the lower case 74 via the heat transfer sheets 100.

[0054] Furthermore, the lower protective wall portion 122 is provided with a fitting protrusion 132 that protrudes downward toward the case main body 68 and fits into the fitting hole 86. The fitting protrusion 132 is provided at a position corresponding to the fitting hole 86 in the upper case 72, and in this embodiment, four fitting protrusions 132 are provided. Specifically, three fitting protrusions 132 are provided on the lower protective wall portion 122 covering the first accommodation area 128a, and one fitting protrusion 132 is provided on the lower protective wall portion 122 covering the second accommodation area 128b. The width dimension in the front-rear direction of each fitting protrusion 132 is smaller than the width dimension b in the front-rear direction of each fitting hole 86, and each fitting protrusion 132 is displaceable in the front-rear direction within each fitting hole 86. In short, the cover portion 70 is displaceable in the front-rear direction by an amount that allows each fitting projection 132 to be displaced within each fitting hole 86 relative to the case main body 68 (upper case 72) to which the cover portion 70 is attached.

[0055] A locking claw 134 is provided at a protruding end (lower end) of each fitting protrusion 132. These locking claws 134 protrude inward, that is, toward the mounting portion 66 side beyond each fitting hole 86 into which each fitting protrusion 132 is inserted in the case main body 68 (upper case 72) to which the cover portion 70 is assembled.

[0056] Although the method for forming the cover portion 70 is not limited, in this embodiment, the cover portion 70 is formed by injection molding, and punch holes 136 for forming the lock claws 134 by injection molding are formed in positions in the horizontal wall portion 106 facing each lock claw 134. In particular, in this embodiment, each punch hole 136 is substantially rectangular and is formed with a size that prevents the insertion of a tool such as a screwdriver used for fastening a bolt. Specifically, the left-right width dimension c (see FIG. 5) of each punch hole 136 is smaller than the front-rear width dimension d (see FIG. 5).

[0057] In this embodiment, the first bolts 138, 138 and the second bolts 140, 140 are respectively housed in the first cylindrical portions 114, 114 and the second cylindrical portions 116, 116 of the cover portion 70 shaped as described above. The first and second bolts 138, 140 have substantially the same shape, a shaft portion 142 has a predetermined maximum outer diameter dimension φB (see FIG. 14), and an insulation processing portion 146 is provided on a head portion 144. The maximum outer diameter dimension φC of the head 144 including the insulating treatment portion 146 is larger than the inner diameter dimension φA' at the outer opening 120 of each of the first and second tubular portions 114, 116, and the outer peripheral edge portion of the head 144 including the insulating treatment portion 146 abuts against the retaining projections 118 of each of the first and second tubular portions 114, 116, thereby preventing the first and second bolts 138, 140 from coming off each of the first and second tubular portions 114, 116. Note that the method of providing the insulating treatment portion 146 on the head 144 of each of the first and second bolts 138, 140 is not limited, and for example, a synthetic resin cap may be fitted onto the head 144 of each of the first and second bolts 138, 140 to fix it, or the cap and the bolt may be formed integrally.

[0058] <Connection busbar 30> In this embodiment, two bus bars are used as the connection bus bars 30 housed in the case 18, with the first connection bus bar 30a on the left and the second connection bus bar 30b on the right. As shown in Fig. 14, both the first and second connection bus bars 30a, 30b have a horizontal portion 148 that extends horizontally at the lower end, and a vertical portion 150 that protrudes upward and extends in the up-down direction at the horizontal rear end. That is, both the first and second connection bus bars 30a, 30b are generally L-shaped overall.

[0059] A first internal connection portion 22a conductively connected to the first circuit side connection portion 20a is provided at a front end portion 151a (an end portion of the horizontal portion 148 opposite to the side connected to the vertical portion 150) of the first connection busbar 30a. A first external connection portion 28a connected to the first connector side connection portion 26a is provided at an upper end portion 151b (an end portion of the vertical portion 150 opposite to the side connected to the horizontal portion 148) of the first connection busbar 30a. Similarly, a second internal connection portion 22b conductively connected to the second circuit side connection portion 20b is provided at a front end portion 151a of the second connection busbar 30b. A second external connection portion 28b connected to the second connector side connection portion 26b is provided at an upper end portion 151b of the second connection busbar 30b. That is, in each connection busbar 30a, 30b, a front end portion 151a serving as a first end portion extends in the front-to-rear direction (from rear to front), and an upper end portion 151b serving as a second end portion extends in the up-down direction (from bottom to top).

[0060] In the first and second connection busbars 30a and 30b, a first bolt insertion hole 152 penetrating in the plate thickness direction (vertical direction) is formed in each of the internal connection portions 22a and 22b. In this embodiment, the first bolt insertion hole 152 is substantially circular and has a predetermined inner diameter dimension φD (see FIG. 14). The inner diameter dimension φD of the first bolt insertion hole 152 is larger than the maximum outer diameter dimension φB of the shaft portion 142 of the first bolt 138, and the space between the first bolt insertion hole 152 and the shaft portion 142 of the first bolt 138 is a tolerance absorbing gap 154 ​​that can absorb tolerance when the first bolt 138 is inserted into the first bolt insertion hole 152. In other words, the first bolt insertion hole 152 is provided with a size that includes the tolerance absorbing gap 154. Since the first bolt insertion hole 152 is approximately circular, the tolerance absorption gap 154 ​​is a circular ring shape extending around the entire circumferential direction, and the horizontal direction including the front-to-back and left-to-right directions is the tolerance absorption direction, which is the direction in which tolerances can be absorbed in the first bolt insertion hole 152.

[0061] Further, in the first and second connection busbars 30a, 30b, second bolt insertion holes 156 are formed in the external connection portions 28a, 28b, penetrating them in the plate thickness direction (front-rear direction). In this embodiment, the second bolt insertion holes 156 are substantially circular and have a predetermined inner diameter dimension φE (see FIG. 14). The inner diameter dimension φE of the second bolt insertion holes 156 is larger than the maximum outer diameter dimension φB of the shaft portion 142 of the second bolt 140, and the space between the second bolt insertion holes 156 and the shaft portion 142 of the second bolt 140 is a tolerance absorbing gap 158 that can absorb the tolerance when the second bolt 140 is inserted into the second bolt insertion hole 156. That is, the second bolt insertion hole 156 is provided with a size that includes the tolerance absorbing gap 158. Since the second bolt insertion hole 156 is approximately circular, the tolerance absorption gap 158 is in a circular ring shape extending around the entire circumferential direction, and the direction perpendicular to the front-to-back direction, including the up-down and left-right directions, is the tolerance absorption direction, which is the direction in which tolerances can be absorbed in the second bolt insertion hole 156.

[0062] <Assembly process of the circuit unit 10 in the vehicle-mounted component> Next, a specific example of the assembly process of the circuit unit 10 will be described. Note that the assembly process of the circuit unit 10 is not limited to the following description.

[0063] First, the first to fourth conduction bus bars 62a to 62d are fixed to the connection portions 60 of the first and second relays 58a and 58b by fastening the bolts 160. The first and second relays 58a and 58b to which the first to fourth conduction bus bars 62a to 62d are fixed are then bolted to the upper wall 76 of the upper case 72. Thereafter, the upper case 72 and the lower case 74 are assembled and fixed to each other by a locking mechanism (not shown). As a result, the first to fourth heat dissipation portions 64a to 64d of the first to fourth conduction bus bars 62a to 62d come into contact with the heat transfer surface 104 of the lower wall 88 via the heat transfer sheets 100. The heat transfer sheets 100 may be previously attached to the lower surfaces of the first to fourth heat dissipation portions 64a to 64d, or may be attached to the upper surface (heat transfer surface 104) of the lower wall 88. As a result, the case body 68 in which the circuit components 16 are housed is completed.

[0064] In a completed state of the case body 68, the first and second bus bar fixing portions 96a, 96b of the lower case 74 abut from below against the first and second circuit side connecting portions 20a, 20b of the second and third conductivity bus bars 62b, 62c. The first and second circuit side connecting portions 20a, 20b are exposed to the outside through the first and second through windows 84a, 84b of the upper case 72.

[0065] Thereafter, the first and second connection busbars 30a, 30b are placed on the placement portion 66 of the upper case 72. As a result, the first and second internal connection portions 22a, 22b of the first and second connection busbars 30a, 30b are overlapped with the first and second circuit side connection portions 20a, 20b exposed to the outside. As a result, the bolt insertion holes constituting the first and second circuit side connection portions 20a, 20b communicate with the first bolt insertion holes 152 provided in the first and second internal connection portions 22a, 22b. Then, the first and second bolts 138, 140 are inserted into the first and second bolt insertion holes 152, 156 of the first and second connection busbars 30a, 30b, respectively. At this point, the first bolts 138 are not yet fastened to the nuts 98 located below the first and second circuit-side connecting portions 20a, 20b.

[0066] Next, the cover portion 70 is assembled to the upper case 72 with the first and second bolts 138, 140 inserted into the first and second bolt insertion holes 152, 156. Specifically, the fitting protrusions 132 of the cover portion 70 are inserted into the fitting holes 86 of the upper case 72, and the locking claws 134 are engaged with the edge of the fitting holes 86 on the mounting portion 66 side in the upper wall 76 of the upper case 72, as shown in FIG. 10. As a result, the first and second connection bus bars 30a, 30b are accommodated in the first and second accommodation regions 128a, 128b of the cover portion 70, and the first and second bolts 138, 140 are accommodated in the first and second cylindrical portions 114, 116, while the cover portion 70 is assembled to the case main body 68. As a result, the in-vehicle component circuit unit 10, which is the subject of the present disclosure, is completed. An external circuit (not shown) is electrically connected to the first and fourth conductive bus bars 62a, 62d in the in-vehicle component circuit unit 10 at an appropriate timing.

[0067] In the assembled state of the in-vehicle component circuit unit 10 (a state in which the in-vehicle component (battery pack 12) is not housed in the housing 14), the first and second bolts 138, 140 are not fastened anywhere and are disposed relatively freely (in a floating state) in the first and second tubular portions 114, 116. In this state, as shown in FIG. 15, the lower end of each of the first bolts 138 is in contact with the nut 98, and an insulating processing portion 146 provided on a head 144 of each of the first bolts 138 protrudes outward from an outer opening 120 in each of the first tubular portions 114. In the fastened state of each of the first bolts 138 described later, the insulating processing portion 146 provided on the head 144 of each of the first bolts 138 is housed in each of the first tubular portions 114. In this state, since the second bolts 140 are relatively free within the second tubular portions 116, the insulation processing portions 146 provided on the heads 144 of the second bolts 140 may protrude outward from the outer openings 120 of the second tubular portions 116, or may be contained within the second tubular portions 116.

[0068] Next, a specific example of a process for housing the circuit unit 10 in the housing 14 of the on-board component (battery pack 12) will be described. Note that the process for housing the circuit unit 10 in the housing 14 of the on-board component (battery pack 12) is not limited to the following description.

[0069] First, the circuit unit 10 is placed in the housing body 32 with the connector 24 attached to the rear wall 40. As a result, the lower surface of the case body 68 contacts the bottom wall 36 of the housing 14 via the gap fillers 102. Also, the second bolts 140 inserted into the second bolt insertion holes 156 are aligned with the connector side connecting parts 26a, 26b of the connector 24. In this state, as shown in FIG. 16, the second bolts 140 are not fastened to the connector side connecting parts 26a, 26b. Then, the front end (rear end) of each second bolt 140 contacts the opening of each connector side connecting part 26a, 26b, and the insulating processing part 146 provided on the head 144 of each second bolt 140 protrudes outward from the outer opening 120 of each second cylindrical part 116. When each second bolt 140 is in a fastened state, which will be described later, an insulation treatment portion 146 provided on a head 144 of each second bolt 140 is housed within each second cylindrical portion 116 .

[0070] From this state, a tool or the like is inserted through the outer openings 120 of the second cylindrical portions 116 to fasten the second bolts 140 to the connector side connecting portions 26a, 26b. This electrically connects the connector 24 and the connection bus bars 30a, 30b through the second bolts 140. Thereafter, a tool or the like is inserted through the outer openings 120 of the first cylindrical portions 114 to fasten the first bolts 138 to the nuts 98 through the first bolt insertion holes 152 and the circuit side connecting portions 20a, 20b. This electrically connects the second and third conduction bus bars 62b, 62c electrically connected to the relays 58a, 58b to the connection bus bars 30a, 30b through the first bolts 138. As a result, the external circuit is electrically connected to the connector 24 via the circuit components 16 (first to fourth conduction bus bars 62a to 62d, first and second relays 58a, 58b) and the first and second connection bus bars 30a, 30b. After fastening the first and second bolts 138, 140, the cover 34 is fixed to the upper opening of the housing main body 32, completing the storage of the on-vehicle component circuit unit 10 in the housing 14 of the on-vehicle component (battery pack 12).

[0071] The circuit unit 10 can be removed from the housing 14 of the battery pack 12 by reversing the above steps. That is, after releasing the fastening between the first bolts 138 and the nuts 98, the fastening between the second bolts 140 and the connector side connecting portions 26a, 26b is released. This allows the circuit unit 10 to be removed from the housing 14 of the battery pack 12. The connection between the external circuit (not shown) and the first and fourth conductive bus bars 62a, 62d is released at an appropriate timing.

[0072] In this manner, with the in-vehicle component circuit unit 10 housed in the housing 14 of the in-vehicle component (battery pack 12), the internal connection portions 22a, 22b of the connection bus bars 30a, 30b provided in the case 18 and the circuit side connection portions 20a, 20b are fastened by the first bolts 138. Here, while housed in the housing regions 128a, 128b of the cover portion 70, the connection bus bars 30a, 30b are displaceable in the front-rear direction (see FIG. 5) together with the cover portion 70 relative to the case body 68, and the inner diameter dimension φD of each first bolt insertion hole 152 is also larger than the maximum outer diameter dimension φB of the shaft portion 142 of each first bolt 138 in the front-rear direction. As a result, even if the positions of each first bolt insertion hole 152 and each circuit side connection portion 20a, 20b are misaligned in the front-to-rear direction due to tolerances when fastening the first bolt 138, the tolerances are absorbed and the first bolt 138 can be fastened more reliably.

[0073] Similarly, each connection bus bar 30a, 30b is displaceable in the left-right direction (see FIG. 5) within each accommodation region 128a, 128b of cover portion 70, and the inner diameter dimension φD of each first bolt insertion hole 152 through which each first bolt 138 is inserted in each internal connection portion 22a, 22b is also made larger in the left-right direction than the maximum outer diameter dimension φB of each first bolt 138 at the shaft portion 142. As a result, even if the positions of each first bolt insertion hole 152 and each circuit side connection portion 20a, 20b are misaligned in the left-right direction due to tolerance when fastening first bolt 138, the tolerance is absorbed and first bolt 138 can be fastened more reliably.

[0074] Furthermore, the external connection parts 28a, 28b and the connector side connection parts 26a, 26b of the connection bus bars 30a, 30b provided in the case 18 are fastened by the second bolts 140. Here, the inner diameter dimension φE of each second bolt insertion hole 156 is made larger than the maximum outer diameter dimension φB of the shaft part 142 of each second bolt 140 in the vertical direction. As a result, even if the positions of each second bolt insertion hole 156 and each connector side connection part 26a, 26b are misaligned in the vertical direction due to tolerance, for example, by adjusting the elastic deformation amount (compression amount) of the heat transfer sheet 100 or the gap filler 102, the tolerance is absorbed and the second bolt 140 can be fastened more reliably.

[0075] Furthermore, the inner diameter dimension φE of each second bolt insertion hole 156, through which each second bolt 140 is inserted, in each external connection portion 28a, 28b of each connection bus bar 30a, 30b is also made larger in the left-right direction than the maximum outer diameter dimension φB of the shaft portion 142 of each second bolt 140. As a result, even if the positions of each second bolt insertion hole 156 and each connector side connection portion 26a, 26b are misaligned in the left-right direction due to tolerance when fastening second bolt 140, the tolerance is absorbed and second bolt 140 can be fastened more reliably.

[0076] Furthermore, each of the connection bus bars 30a, 30b is provided inside the case 18, and each of the connection bus bars 30a, 30b is covered by the case 18 (cover portion 70) except for each of the first window portions 110a, 110b and the second window portions 112a, 112b. This can reduce the risk of an operator unintentionally coming into contact with a live part and receiving an electric shock during bolt fastening work, etc.

[0077] In particular, in this embodiment, although the bolt tightening process is not limited, first, the external connection parts 28a, 28b and the connector side connection parts 26a, 26b are tightened with the second bolts 140, and then the internal connection parts 22a, 22b and the circuit side connection parts 20a, 20b are tightened with the first bolts 138. As a result, when the second bolts 140 are tightened, the tightening part on the first bolt 138 side to which power is supplied is in an untightened state, and the tightening part on the second bolt 140 side does not become an energized part, allowing the bolt tightening process to be performed more safely.

[0078] The left and right first windows 110a, 110b and second windows 112a, 112b are surrounded by first and second cylindrical portions 114, 116 that protrude outward from the case 18. This further reduces the risk of electric shock when the first and second bolts 138, 140 are fastened and come into contact with a bolt fastening portion that may be an active portion through the first windows 110a, 110b and the second windows 112a, 112b.

[0079] The first and second bolts 138, 140 are housed inside the left and right first windows 110a, 110b and the second windows 112a, 112b, and the first and second bolts 138, 140 are prevented from coming off the first and second tubular parts 114, 116 by the retaining protrusions 118. This improves the workability of fastening the bolts without the need to prepare and fasten the first and second bolts separately. In particular, the retaining protrusions 118 can reduce the opening dimensions of the outer openings 120 of the first and second tubular parts 114, 116, further reducing the risk of electric shock when fastening the bolts.

[0080] Since each of the first and second bolts 138, 140 has an insulating treatment part 146 on the head 144, the risk of an operator receiving an electric shock through a tool or the like during bolt tightening can be reduced. In particular, each of the first and second bolts 138, 140 has the insulating treatment part 146 protruding outward from the outer opening 120 when the bolt is not tightened, and is housed inside the outer opening 120 when the bolt is tightened, so that it is possible to visually determine from the outside whether each of the first and second bolts 138, 140 is in a tightened state or an untightened state. Furthermore, since the insulating treatment part 146 of each of the first and second bolts 138, 140 only protrudes outward even when the bolt is not tightened, the risk of an operator receiving an electric shock through unintentional contact can be reduced.

[0081] The case 18 has a case main body 68 on which the connection bus bars 30a, 30b are placed, and a cover portion 70 that covers the connection bus bars 30a, 30b and is attached to the case main body 68. The cover portion 70 and the connection bus bars 30a, 30b are integrally displaceable in the front-to-rear direction relative to the case main body 68. This prevents the connection bus bars 30a, 30b from being exposed from the cover portion 70 (case 18) when they are displaced in the front-to-rear direction, for example, and further reduces the risk of an operator unintentionally coming into contact with the connection bus bars 30a, 30b and receiving an electric shock. Furthermore, since the cover portion 70 is provided with the first window portions 110a, 110b and the second window portions 112a, 112b, and the cover portion 70 and the connection bus bars 30a, 30b are displaced integrally, the opening dimensions of the first window portions 110a, 110b and the second window portions 112a, 112b can be set small without forming the first window portions and the second window portions large to match the displacement of the connection bus bars, thereby further reducing the risk of electric shock.

[0082] The case body 68 has a fitting hole 86 extending in the front-rear direction, and the cover part 70 has a fitting protrusion 132 that fits into the fitting hole 86, and the fitting protrusion 132 is capable of being displaced in the front-rear direction within the fitting hole 86. This allows the cover part 70 to be displaced in the front-rear direction relative to the case body 68 while maintaining the assembled state of the case body 68 and the cover part 70.

[0083] In particular, the fitting protrusion 132 has a locking claw 134, which protrudes inward toward the mounting portion 66 side beyond the fitting hole 86. This locking claw 134 is adapted to engage with the edge of the fitting hole 86 on the mounting portion 66 side in the upper case 72 when the cover portion 70 is assembled to the case body 68. As a result, the engagement portion between the locking claw 134 and the case body 68 (fitting hole 86) cannot be visually confirmed from the outside, and even if a tool such as a screwdriver is inserted into the fitting hole 86, it is difficult to bend the fitting protrusion 132 in a direction to release the engagement between the locking claw 134 and the fitting hole 86. Therefore, the assembled state of the case body 68 and the cover portion 70 is stably maintained, and for example, it is possible to avoid electric shock due to unintentional contact with each of the connection bus bars 30a, 30b.

[0084] The cover portion 70 has ribs 130 on the surfaces on which the connection bus bars 30a, 30b are overlapped, and these ribs 130 suppress upward displacement of the connection bus bars 30a, 30b, and therefore the circuit components 16 including the second and third conduction bus bars 62b, 62c. This allows the heat dissipation portions 64a-64d to be in contact with the heat transfer surface 104 on the bottom wall 88 of the lower case 74 more reliably via the heat transfer sheet 100, improving the efficiency of heat dissipation through the housing 14 of the battery pack 12. In particular, in this embodiment, heat generated at the connection portion (the fastening portion of each second bolt 140) between the connector 24 and the circuit unit 10 in the vehicle-mounted component can also be dissipated through the housing 14 of the battery pack 12, for example, via each connection bus bar 30a, 30b and the second and third conductive bus bars 62b, 62c (second and third heat dissipation portions 64b, 64c).

[0085] Each of the connection bus bars 30a, 30b has a front end 151a as a first end extending in the front-rear direction and an upper end 151b as a second end extending in the up-down direction, and each front end 151a is provided with a first bolt insertion hole 152, and each upper end 151b is provided with a second bolt insertion hole 156. The inner diameter dimension φD of each of the first bolt insertion holes 152 is larger than the outer diameter dimension φB of the shaft portion 142 of each of the first bolts 138 in the horizontal direction including the front-rear direction and the left-right direction, and a tolerance absorbing gap 154 ​​is provided. The inner diameter dimension φE of each of the second bolt insertion holes 156 is larger than the outer diameter dimension φB of the shaft portion 142 of each of the second bolts 140 in the direction perpendicular to the front-rear direction including the up-down direction and the left-right direction, and a tolerance absorbing gap 158 is provided. This allows the tolerance absorption direction in each of the first bolt insertion holes 152 and the tolerance absorption direction in each of the second bolt insertion holes 156 to be different from each other, making it possible to absorb tolerances in a plurality of directions.

[0086] <Other embodiments> The technology described in this specification is not limited to the embodiments described in the above description and drawings, and for example, the following embodiments are also included in the technical scope of the technology described in this specification.

[0087] (1) In the above embodiment, each of the connection busbars 30a, 30b is formed by bending a single metal flat plate, but as shown in Fig. 17, the first and second connection busbars 170a, 170b may be configured as a laminate of multiple thin plates 172. This allows each of the connection busbars 170a, 170b to flexibly deform, for example, even when the length of each connection busbar is short and a single flat busbar has a relatively large deformation rigidity. As a result, tolerances can be absorbed more efficiently, and the circuit side connection portion and the connector side connection portion can be stably connected to each of the connection busbars 170a, 170b.

[0088] (2) In the above embodiment, the heat transfer sheet 100 and the gap filler 102 are elastically deformable in the vertical direction, so that the in-vehicle component circuit unit 10 can be displaced in the vertical direction relative to the housing 14 of the battery pack 12, and the vertical tolerance is absorbed, but the present invention is not limited to this embodiment. For example, a vertical play may be provided in the fitting portion between the fitting protrusion and the fitting hole (the engagement portion between the lock claw and the upper wall of the upper case) and the cover portion and the connection bus bar may be fixed, so that the connection bus bar displaces vertically together with the cover portion relative to the case, and the vertical tolerance is absorbed. Also, the fitting protrusion may be displaceable in the horizontal direction within the fitting hole, so that the connection bus bar can be displaced horizontally together with the cover portion relative to the case.

[0089] (3) In the above embodiment, the left and right first windows 110a, 110b and the second windows 112a, 112b are provided in the cover portion 70, but the cover portion is not essential. In other words, the connection bus bar may be displaceably housed in a case consisting of an upper case and a lower case, and the first window portion and the second window portion may be formed in the top wall of the upper case.

[0090] (4) In the above embodiment, the insulation portion 146 is provided on the head 144 of each of the first and second bolts 138, 140, but the shape of the insulation portion is not limited to this. For example, if a hexagonal hole is provided in the central protrusion of the insulation portion and a tool is inserted into the hole to tighten the bolt, it is possible to reduce the opening dimensions of the outer openings of the first and second cylindrical portions.

[0091] (5) The first and second bolts are not limited to being housed in the first and second tubular portions, and may be fastened to the circuit-side connecting portion and the connector-side connecting portion as separate bodies from the circuit unit in an on-board component according to the present disclosure. In other words, the first and second tubular portions are not essential to the circuit unit in an on-board component according to the present disclosure.

[0092] (6) In the above embodiment, the nut 98 and the connector side connecting portions 26a, 26b are arranged in a waiting state to be fastened to the first and second bolts 138, 140 housed in the first tubular portion 114 and the second tubular portion 116, but for example, the first and second bolts may be arranged in a protruding state and the nut may be fastened. The nut may be housed and arranged in the first and second tubular portions as described above, or may be separate from the circuit unit in the on-vehicle component according to the present disclosure.

[0093] (7) In the above embodiment, the retaining projection 118 is annular and continuous over the entire circumference in the circumferential direction, but it may be provided partially in the circumferential direction.

[0094] (8) In the above embodiment, two connection bus bars 30a, 30b are provided, but the number of connection bus bars may be one or three or more. Furthermore, the number of relays and conduction bus bars may be changed according to the number of connection bus bars, and the types, shapes, numbers, etc. of the components constituting the circuit components are not limited.

[0095] (9) In the above embodiment, the tolerance absorbing directions are set to the front-rear direction, the left-right direction, and the up-down direction, but are not limited thereto. If only one tolerance absorbing direction is required, the connecting bus bar may be displaceable in only one direction, or in an oblique direction.

[0096] (10) In the above embodiment, the first and second bolt insertion holes 152, 156 are each formed to be perfectly circular. However, they may instead be formed to be elongated holes extending in the tolerance absorbing direction.

[0097] (11) In the above embodiment, the ribs 130 are provided on the inner surface of the cover portion 70 to suppress the lifting of the first and second connection bus bars 30a, 30b, thereby suppressing the lifting of the second and third conduction bus bars 62b, 62c connected to the first and second connection bus bars 30a, 30b, but the present invention is not limited to this embodiment. For example, instead of or in addition to the ribs on the cover portion, ribs may also be provided on the inner surface of the upper case, and the lifting of the conduction bus bars may be suppressed by the ribs on the inner surface of the upper case. As a result, contact between the heat dissipation portion of each conduction bus bar and the heat transfer surface of the case body is maintained, and a good heat dissipation effect is achieved.

[0098] (12) In the above embodiment, when the first and second bolts 138, 140 are not fastened, the insulation processing portion 146 provided on the heads 144 of the first and second bolts 138, 140 protrudes from the first and second tubular portions 114, 116 to the outside, but the present invention is not limited to this embodiment. That is, for example, by making the protruding height dimension from the horizontal wall portion and the vertical wall portion of the cover portion in each of the first and second tubular portions larger than the overall length (including the insulation processing portion) of the first and second bolts in the unfastened state as shown in Figs. 15 and 16, the entire first and second bolts including the insulation processing portion provided on the heads may be accommodated in each of the first and second tubular portions. In that case, the insulation processing portion may not be provided on the heads of each of the first and second bolts, and the first and second bolts are accommodated in the first and second tubular portions even in the unfastened state, thereby preventing an operator from unintentionally touching the first and second bolts and receiving an electric shock. [Explanation of symbols]

[0099] 10. Circuit unit in vehicle components 12 Battery pack (vehicle component) 14. Chassis 16 Circuit components 18 cases 20 Circuit side connection part 20a First circuit side connection part 20b Second circuit side connection part 22 Internal Connections 22a First internal connection 22b Second internal connection 24 Connectors 26 Connector side connection part 26a First connector side connection part 26b Second connector side connection part 28 External connection part 28a First external connection 28b Second external connection 30 Connection busbar 30a 1st connection busbar 30b Second connection bus bar 32 Main unit 34 Lid 36 Bottom Wall 38 Peripheral wall section 40 Rear wall 42 Connector insertion hole 44 Volts 46 Electric wire 48 core wire 50 Insulation coating 52 Connector housing 54 Connector terminal 56 Mounting part 58a 1st Relay 58b 2nd Relay 60 Connection 62 Conductive busbar 62a First Conduction Bus Bar 62b Second conductive bus bar 62c 3rd Conduction Bus Bar 62d 4th Conduction Bus Bar 64 Heat radiation part 64a First heat dissipation section 64b 2nd heat dissipation section 64c 3rd heat dissipation section 64d 4th heat dissipation section 66 Placement section 68 Case body 70 Cover part 72 Upper Case 74 Lower Case 76 Upper Wall 78 Upper peripheral wall 79 Rear end wall 80 Upper front wall 82 Upper back wall 84 Through window 84a First through window 84b Second through window 86 Mating hole 88 Lower Wall 90 Lower peripheral wall 92 Lower front wall 94 Lower back wall 96 Busbar fixing part 96a First busbar fixing part 96b Second bus bar fixing part 98 Nut 100 Heat transfer sheet 102 Gap Filler 104 Heat Transfer Surface 106 Horizontal wall section 108 Vertical wall 110 First window 110a Left first window 110b 1st window on the right side 112 Second window 112a Second window on the left side 112b Second window on the right side 114 First cylinder part (cylindrical part) 116 Second cylinder part (cylindrical part) 118 Anti-slip protrusion 120 Outer opening 122 Lower protective wall 124 Rear protection wall 126 Partition wall 128a First Containment Area 128b Second Containment Area 130 Ribs 132 Fitting protrusion 134 Locking Claw 136 Die-Cut Hole 138 First Bolt 140 Second Bolt 142 Shaft 144 Head 146 Insulation Processing Section 148 Horizontal section 150 Vertical section 151a Front end (first end) 151b Upper end (second end) 152 First bolt hole 154 Tolerance compensation gap 156 Second bolt insertion hole 158 Tolerance compensation gap 160 volts 170a 1st connection busbar 170b Second connection bus bar 172 Thin plate

Claims

1. An in-vehicle component circuit unit that is housed in a housing of an in-vehicle component, A circuit component; an insulating case that houses the circuit components; a connection bus bar that is housed in the case and has an internal connection portion that is conductively connected to a circuit-side connection portion provided on the circuit component, and an external connection portion that is conductively connected to a connector-side connection portion of a connector provided on the housing; a first window portion provided in the case and arranged to face the internal connection portion of the connection bus bar and a first bolt insertion hole provided in the internal connection portion; a second window portion provided in the case and arranged to face the external connection portion of the connection bus bar and a second bolt insertion hole provided in the external connection portion, the first bolt insertion hole and the second bolt insertion hole are provided with a size including a tolerance absorbing gap extending in a tolerance absorbing direction, the connection bus bar is accommodated in the case so as to be displaceable in the tolerance absorbing direction, the first window portion is opened to a size that allows a bolt fastening operation of the internal connection portion to the circuit side connection portion through the first window portion from the outside of the case, the second window portion is opened to a size that allows a bolt fastening operation of the external connection portion to the connector-side connection portion through the second window portion from the outside of the case. Circuit unit inside an in-vehicle component.

2. The circuit unit according to claim 1 , wherein the first window portion and the second window portion are each surrounded by a cylindrical portion protruding outwardly from the case.

3. 3. The circuit unit in an in-vehicle component according to claim 2, wherein a bolt or a nut is accommodated inside each of the tubular portions of the first window portion and the second window portion, and a radially inward anti-slip protrusion is provided on the protruding tip side of the tubular portion, and the bolt or the nut is prevented from coming off the tubular portion by contacting the anti-slip protrusion.

4. The bolt or the nut housed in each of the cylindrical portions has an insulating treatment portion, The circuit unit in an on-vehicle component according to claim 3 , wherein the insulating portion of the bolt or the nut is capable of protruding from the tubular portion in an unfastened state and is housed within the tubular portion in a fastened state.

5. the case includes a case main body having a mounting portion on which the connection bus bar is mounted, and a cover portion attached to cover the mounting portion and movable in the tolerance absorbing direction relative to the case main body, The circuit unit in an on-vehicle component according to claim 1 , wherein the cover portion has the first window portion and the second window portion, and is displaced in the tolerance absorbing direction together with the connection bus bar.

6. the case body has a fitting hole extending in the tolerance absorbing direction around the mounting portion, 6. The circuit unit in an in-vehicle component according to claim 5, wherein the cover portion has an engagement protrusion that protrudes from a peripheral portion of the cover portion toward the case body and engages with the engagement hole, and a width dimension of the engagement protrusion in the tolerance absorption direction is smaller than that of the engagement hole.

7. the fitting projection has a locking claw provided at a protruding end portion and protruding toward the placement portion side beyond the fitting hole, The circuit unit according to claim 6 , wherein the locking claw inserted into the fitting hole engages with an edge of the fitting hole on the side of the mounting portion.

8. The internal connection portion and the external connection portion extend in directions intersecting each other, the first bolt insertion hole provided in the internal connection portion and the second bolt insertion hole provided in the external connection portion penetrate in directions intersecting each other, 8. The circuit unit in an on-vehicle component according to claim 1, wherein the tolerance absorption direction in the tolerance absorption gap of the first bolt insertion hole and the tolerance absorption direction in the tolerance absorption gap of the second bolt insertion hole are mutually perpendicular directions.

9. 8. The circuit unit in an in-vehicle component according to claim 5, wherein the cover portion has a rib protruding toward the mounting portion, and when the cover portion is assembled to the case body, the rib abuts against or faces the connection bus bar.

10. the connection bus bar has a first end provided with the internal connection portion and a second end provided with the external connection portion and protruding upward from the first end, 10. The circuit unit in an on-vehicle component according to claim 1, wherein the internal connection portion has the first bolt insertion hole having the tolerance accommodating gap in the extension direction of the first end, and the external connection portion has the second bolt insertion hole having the tolerance accommodating gap in the extension direction of the second end.

11. The circuit unit in an on-vehicle component according to claim 1 , wherein the connection bus bar is a laminate of a plurality of thin plates.

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