Locking structure and busbar module equipped with locking structure

Abstract

To provide an excellent locking structure and a busbar module equipped with the locking structure that can reduce the height of a fixing member that holds a fixed member.SOLUTION: A locking structure includes a cantilevered flexible arm 31 that protrudes from an outer surface 28 of a busbar accommodating portion 21 and extends along the outer surface 28 with its tip 31a facing the fixing direction of a busbar 11, and a locking protrusion 35 that protrudes from the inner surface of the tip 31a and locks the periphery of the busbar 11. The locking protrusion 35 is configured such that the distance from an imaginary plane S that includes the outer surface 28 of the busbar accommodating portion 21 is greater than the distance from a support point F of the flexible arm 31 to the imaginary plane S that includes the outer surface 28 of the busbar accommodating portion 21.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a locking structure and a busbar module equipped with the locking structure. [Background technology]

[0002] In a conventional battery pack for use in an automobile, such as a hybrid vehicle or an electric vehicle, which is connected to a power conversion device for driving a motor, a battery module is formed by stacking a large number of battery cells side by side, alternately facing in opposite directions, so that the positive and negative terminals of the battery cells are adjacent to each other. The electrode terminals of adjacent battery cells are connected by connecting members such as bus bars, so that the battery cells are connected in series or parallel.

[0003] When assembling a battery module with the above configuration, it is necessary to connect multiple electrode terminals with bus bars. Therefore, a bus bar module is used in which bus bars are housed in bus bar housings in an insulating resin wiring body according to the number of electrode terminals to be connected (see, for example, Patent Documents 1 and 2).

[0004] As shown in FIG. 11, for example, each busbar accommodating section 121 of a busbar module 101 has a frame-shaped peripheral wall (fixing member) 123 that is arranged and formed to match the outer shape of the busbar 11, and supports the busbar (fixed member) 11 by a mounting section 127 provided on one side wall of the peripheral wall 123.

[0005] The bus bar 11 is formed from a conductive metal plate and has a plurality of fastening holes 15. These fastening holes 15 are formed at the same pitch as the electrodes along the arrangement direction of the unit cells of the battery pack, and the electrodes are inserted into these fastening holes 15. A snap fit (flexible arm) 131 provided on peripheral wall 123 as a locking structure engages and accommodates the periphery (engaged portion) of bus bar 11 placed on mounting portion 127 and accommodated in bus bar accommodating portion 121, whereby bus bar 11 is surrounded by peripheral wall 123 and held without any rattle.

[0006] Snap fit 131 is a cantilevered flexible arm whose tip is integrally molded with part 140 of peripheral wall 123 so as to extend in the fixing direction of the bus bar (downward in the drawing). A locking projection 135 for locking the periphery of bus bar 11 is provided on the inner surface of the tip.

[0007] When busbar 11 is inserted, the periphery of busbar 11 presses against the upper surface of locking protrusion 135, causing snap fit 131 to bend outward using base 133 as a support point, allowing busbar 11 to be inserted, and then locking protrusion 135 of snap fit 131, which has returned to its original elastic state, locks the periphery of busbar 11. This prevents busbar 11 from slipping out of busbar accommodating portion 121. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-18499 [Patent Document 2] Patent Publication No. 2021-136163 Summary of the Invention [Problem to be solved by the invention]

[0009] However, the conventional snap fit 131 described above is a cantilever-like flexible arm that is integrally molded with a portion 140 of the peripheral wall 123 and extends from a base located above the mounting portion 127 to a tip end in the fixing direction (downward in the figure) of the bus bar 11. Therefore, the snap fit 131 needs to have a certain length to ensure strength against bending, but integrally molding the snap fit 131 with a support point above the locking protrusion 135 increases the height of the peripheral wall 123, making it difficult to reduce the height of the bus bar module 101.

[0010] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an excellent locking structure that enables a fixing member that holds a fixed member to have a low profile, and a bus bar module equipped with this locking structure. [Means for solving the problem]

[0011] The above object of the present invention can be achieved by the following configuration. (1) A locking structure comprising a cantilevered flexible arm protruding from the outer surface of a fixing member and extending along the outer surface so that its tip faces the fixing direction of the fixed member, and a locking protrusion protruding from the inner surface of the tip to lock the locked portion of the fixed member, wherein the locking protrusion is configured so that its distance from an imaginary plane including the outer surface of the fixing member is greater than the support point of the flexible arm. (2) A busbar module including an electric wiring body to be assembled to a battery assembly composed of a plurality of electric cells, and busbars housed in a plurality of busbar housings provided on the electric wiring body and connected to electrodes of the electric cells of the battery assembly, wherein the fixing member is the busbar housing and the fixed member is the busbar, and the busbar module is equipped with the locking structure described in (1) above. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a good locking structure that enables a fixing member that holds a fixed member to have a low profile, and a bus bar module that includes this locking structure.

[0013] The present invention has been briefly described above. The details of the present invention will become clearer by reading the following detailed description of the invention (hereinafter referred to as "embodiments") with reference to the accompanying drawings. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is an exploded perspective view showing a part of a busbar module equipped with a locking structure according to one embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view showing a state in which the bus bar shown in FIG. 1 is held in a bus bar receiving portion. [Figure 3] FIG. 3 is a plan view of the bus bar receiving portion shown in FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 5 is a cross-sectional view taken along line VV of FIG. [Figure 6] FIG. 6 is an enlarged cross-sectional view of a main part illustrating a locking structure when a bus bar is inserted into a bus bar receiving portion. [Figure 7] FIG. 7 is an enlarged cross-sectional view of a main part illustrating a locking structure when the bus bar is lifted up from the bus bar receiving portion. [Figure 8] FIG. 8 is an exploded perspective view showing a part of a bus bar module having a locking structure according to a reference example. [Figure 9] FIG. 9 is an enlarged cross-sectional view of a main part illustrating the locking structure shown in FIG. 8 when the bus bar is inserted into the bus bar receiving portion. [Figure 10] FIG. 10 is an enlarged cross-sectional view of a main part illustrating the locking structure shown in FIG. 8 when the bus bar is lifted up from the bus bar receiving portion. [Figure 11] FIG. 11 is an exploded perspective view showing a part of a bus bar module equipped with a conventional locking structure. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. As shown in Fig. 1, a busbar module 1 equipped with a locking structure according to one embodiment of the present invention is attached to a battery assembly that constitutes a power supply device. Examples of power supply devices include those installed in electric vehicles that run using an electric motor and hybrid vehicles that run using both an engine and an electric motor, and supply power to these electric motors.

[0016] The locking structure according to this embodiment is not limited to bus bar modules, but can be applied to various locking structures between fixing members and fixed members, such as fixing bus bars in electrical connection boxes such as junction boxes, and locking cover members that cover openings in housings.

[0017] The busbar module 1 according to this embodiment includes an electric wiring body 20 made of insulating resin. The electric wiring body 20 is configured by connecting busbar accommodating sections 21, which are fixing members each having a frame-shaped peripheral wall 23 and bridge support sections 24, by hinge sections 25 along the arrangement direction of the batteries in a battery assembly (not shown). Each of the busbar accommodating sections 21 accommodates and holds a busbar 11, which is a member to be fixed.

[0018] One side wall of peripheral wall 23 along the connecting direction of busbar accommodating portion 21 is provided with a placing portion 27 on which busbar 11 is placed. At both longitudinal ends of the mounting portion 27, two flexible arms 31 constituting the locking structure of this embodiment are provided on the outer surface 28 of the peripheral wall 23, respectively. The flexible arm 31 is a cantilever-shaped flexible arm that protrudes from the outer surface 28 of the peripheral wall 23 located below the mounting portion 27 and extends upward along the outer surface 28 so that the tip portion 31a faces the fixing direction of the bus bar 11 (downward in the figure).

[0019] The flexible arm 31 has a pair of legs 33, 33 that extend in a curved manner from a rising portion 31b from the outer surface 28 of the peripheral wall 23 toward a tip portion 31a, and the upper ends of the pair of legs 33, 33 are joined at the tip portion 31a. The pair of legs 33, 33 of the flexible arm 31 are formed by openings formed along the longitudinal direction.

[0020] A locking projection 35 is provided on the inner surface of the tip portion 31a to lock onto the periphery (locked portion) of the bus bar 11. The locking projection 35 is configured so that the distance from the imaginary plane S including the outer surface 28 of the peripheral wall 23 is greater than the distance from the support point F on the rising portion 31b of the flexible arm 31 (see FIG. 6).

[0021] The busbar 11 according to this embodiment is attached to the positive and negative electrodes of adjacent batteries in a battery assembly, thereby connecting the batteries in series. The busbar 11 is obtained by, for example, pressing a conductive metal plate, and is a generally U-shaped metal plate having a fixing plate portion 12 and a pair of connecting portions 13, 13, with a pair of fastening holes 15, 15 through which the positive and negative electrodes of adjacent batteries pass. The pair of fastening holes 15, 15 are respectively arranged in the pair of connecting portions 13, 13 with the same spacing as the positive and negative electrodes of the adjacent batteries.

[0022] As shown in Figures 2 and 3, when the busbar 11 is inserted into the busbar accommodating section 21, the peripheral edges of both longitudinal ends of the fixing plate section 12 press downward against the upper surfaces 35a of the opposing locking protrusions 35, causing the two flexible arms 31 to bend outward with their rising portions (bases) 31b as support points F to allow the busbar 11 to be inserted, and then the locking protrusions 35 of the flexible arms 31, which have returned to their original elastic state, lock the peripheral edges of the busbar 11.

[0023] As a result, the busbar 11, whose fixing plate portion 12 is placed on the mounting portion 27, is prevented from coming out of the busbar accommodating portion 21 by the two flexible arms 31, whose locking protrusions 35 face each other, as shown in Figures 4 and 5.

[0024] Next, the operation of the locking structure configured as described above and the bus bar module equipped with this locking structure will be described with reference to FIGS. As shown in FIG. 6, the flexible arm 31 in this embodiment protrudes from the outer surface 28 of the peripheral wall 23 located below the mounting portion 27 of the busbar accommodating portion 21 on which the fixing plate portion 12 of the busbar 11 is mounted.

[0025] The tip 31a of the flexible arm 31 extends upward along the outer surface 28 so as to face the fixing direction of the bus bar 11 (downward in the figure), and protrudes above the upper surface of the mounting portion 27. In other words, the rising portion 31b, which serves as the support point F of the flexible arm 31, is located below the tip 31a, and only the tip 31a protrudes above the upper surface of the mounting portion 27.

[0026] Therefore, according to the flexible arm 31 of this embodiment, the protruding height of the mounting portion 27 in the busbar accommodating portion 21 from the upper surface can be minimized, and the height of the peripheral wall 23 does not increase, so that the busbar accommodating portion 21 can be made low-profile.

[0027] Furthermore, the locking projection 35 protruding from the inner surface of the tip portion 31a is configured so as to be at a greater distance from an imaginary plane S including the outer surface 28 of the peripheral wall 23 than the support point F at the rising portion 31b of the flexible arm 31. In other words, the support point F of the flexible arm 31 is set closer to the protruding direction of the locking projection 35 (to the right in FIG. 6) than directly below the locking projection 35.

[0028] 6, when busbar 11 is inserted into busbar accommodating portion 21, the peripheral edges of both longitudinal ends of fixing plate portion 12 press downward on upper surfaces 35a of the opposing locking projections 35. At this time, flexible arm 31, whose force point A with respect to upper surfaces 35a of locking projections 35 is located further up the rising direction (outside outer surface 28) than upstanding portion 31b, which is support point F, can bend smoothly (shown by an imaginary line in FIG. 6) in the unlocking direction (direction of the arrow) away from outer surface 28, which is the direction in which locking projections 35 are released.

[0029] 7, when a force acts on the busbar 11 accommodated in the busbar accommodating portion 21 in the lifting direction (direction away from the mounting portion 27), the peripheral edges of both longitudinal ends of the fixing plate portion 12 press upward against the locking surfaces 35b of the opposing locking projections 35. At this time, the flexible arm 31, in which the force point A with respect to the locking surfaces 35b of the locking projections 35 is located further in the rising direction than the rising portion 31b, which is the support point F (outside the outer surface 28), bends (shown by an imaginary line) in the protruding direction of the locking projections 35 (direction of the arrow in FIG. 7), which is the locking direction of the locking projections 35, thereby improving the holding force for the busbar 11.

[0030] Furthermore, according to the flexible arm 31 of this embodiment, the holding force can be improved when a force acts on the bus bar 11 in a lifting direction, so that the same holding force as in the conventional case can be ensured even if the engagement allowance of the locking protrusion 35 is reduced. Therefore, by reducing the engagement allowance of the locking protrusion 35, the bending space of the flexible arm 31 required for inserting the bus bar 11 can be reduced, and the stress acting on the flexible arm 31 can also be reduced.

[0031] Next, a bus bar module 1A having a locking structure according to a reference example will be described with reference to FIGS. The busbar module 1A of the reference example differs from the above embodiment in that the shape of the flexible arm 31A that constitutes the locking structure of the busbar accommodating portion 21A is different. In the following, the same parts as those in the above embodiment are denoted by the same reference numerals and their description will be omitted.

[0032] The busbar module 1A according to this reference example includes an electric wire routing body 20A made of insulating resin. The electric wire routing body 20A is configured by connecting busbar accommodating sections 21A, which are fixing members each having a frame-shaped peripheral wall 23 and a bridge support section 24, by hinge sections 25 along the arrangement direction of the batteries in a battery assembly (not shown). The busbar accommodating sections 21A each accommodate and hold a busbar 11, which is a member to be fixed.

[0033] One side wall of peripheral wall 23 along the connecting direction of busbar accommodating portion 21A is provided with mounting portion 27 on which busbar 11 is placed. Two flexible arms 31A constituting the locking structure of the reference example are provided on peripheral wall 23 at both longitudinal ends of mounting portion 27.

[0034] Flexible arm 31A is a cantilever-shaped flexible arm integrally formed with part of peripheral wall 23 so that tip end 31a extends in the fixing direction of the bus bar (downward in the drawing). This flexible arm 31A has a leg 33A extending upward from the lower portion 40 of the peripheral wall 23, and a locking projection 35A for locking the peripheral edge of the bus bar 11 is provided on the inner surface of the tip 31a of the leg 33A. The locking projection 35A is positioned above the support point F at the base of the leg portion 33A, and is configured so that the upper surface 35a is positioned inside the busbar accommodating portion 21A.

[0035] When the busbar 11 is inserted into the busbar accommodating portion 21A, the peripheral edges of both longitudinal ends of the fixing plate portion 12 press downward on the upper surfaces 35a of the opposing locking projections 35A, causing the two flexible arms 31A to bend outwardly of the busbar accommodating portion 21A to allow the busbar 11 to be inserted, and then the locking projections 35A of the flexible arms 31A, which have returned to their original elastic state, lock the peripheral edges of the busbar 11. As a result, the busbar 11, which has been placed on the mounting portion 27 of the fixing plate portion 12, is prevented from coming out of the busbar accommodating portion 21A by the two flexible arms 31A whose locking projections 35A face each other.

[0036] Flexible arm 31A according to this embodiment has legs 33A extending upward from lower portion 40 of peripheral wall 23 located below mounting portion 27 of busbar accommodating portion 21 on which fixing plate portion 12 of busbar 11 is mounted.

[0037] Then, tip end 31a of leg 33A extends upward to face the fixing direction of bus bar 11 (downward in the figure), and protrudes above the upper surface of mounting portion 27. In other words, the base of leg 33A, which serves as support point F of flexible arm 31A, is located below tip end 31a, and only tip end 31a protrudes from the upper surface of mounting portion 27.

[0038] Therefore, according to the flexible arm 31A of this reference example, the protruding height from the upper surface of the mounting portion 27 in the busbar accommodating portion 21A can be minimized, and the height of the peripheral wall 23 does not increase, so that the busbar accommodating portion 21A can be made low-profile.

[0039] However, the locking projection 35A protruding from the inner surface of the tip portion 31a is configured to be positioned above the support point F at the base of the leg portion 33A. 9, when busbar 11 is inserted into busbar accommodating portion 21, the peripheral edges of both longitudinal ends of fixing plate portion 12 press downward on upper surfaces 35a of opposing locking projections 35A. At this time, flexible arm 31A, whose force point A on upper surfaces 35a of locking projections 35A is located closer to the protruding direction of locking projections 35A (to the right in FIG. 9) than the base of leg portion 33A, which is support point F, cannot bend smoothly in the direction to unlock locking projections 35A. This may cause locking projections 35A to fall in the protruding direction (the direction of the arrow in FIG. 9) and buckle, resulting in partial engagement of busbar 11.

[0040] 10, when a force acts on busbar 11 accommodated in busbar accommodating portion 21A in a lifting direction (a direction away from mounting portion 27), the peripheral edges of both longitudinal ends of fixing plate portion 12 press upward against locking surfaces 35b of the opposing locking protrusions 35. At this time, flexible arm 31A, whose force point A with respect to locking surfaces 35b of locking protrusions 35A is located closer to the protruding direction of locking protrusions 35A (to the right in FIG. 10) than the base of leg portion 33A, which is support point F, bends in the direction to unlock locking protrusions 35A (shown by imaginary lines), thereby reducing the holding force on busbar 11.

[0041] Therefore, in the locking structure having the flexible arm 31A of this reference example, it is possible to reduce the height of the busbar accommodating section 21A, but there is a concern that the busbar 11 may be partially engaged due to buckling of the locking protrusion 35A, or that the flexible arm 31A may not have enough holding force to release the lock. In contrast, the locking structure of the embodiment having the flexible arm 31 described above and the busbar module 1 equipped with this locking structure enable the busbar accommodating section 21 to be made lower in height, and the flexible arm 31 can bend smoothly in the unlocking direction without buckling when the busbar 11 is inserted, thereby improving the holding force for the busbar 11.

[0042] Furthermore, the flexible arm 31 of this embodiment can improve the holding force when a force acts on the busbar 11 in a lifting direction, so that the same holding force as in the conventional case can be ensured even if the flexural rigidity of the flexible arm 31 is reduced. Therefore, the flexural rigidity of the flexible arm 31 is reduced by a pair of legs 33, 33 formed by openings formed along the longitudinal direction, thereby reducing the elastic repulsive force. As a result, the insertion force required when inserting the busbar 11 into the busbar accommodating portion 21 is reduced, improving the workability of the busbar insertion operation.

[0043] Therefore, according to this embodiment, it is possible to provide an excellent locking structure that allows the busbar accommodating portion 21 that holds the busbar 11 to have a low profile, and a busbar module 1 that includes this locking structure.

[0044] The present invention is not limited to the above-described embodiments, and can be appropriately modified, improved, etc. Furthermore, the material, shape, size, number, location, etc. of each component in the above-described embodiments are arbitrary and not limited as long as they can achieve the present invention.

[0045] Here, the features of the locking structure according to the present invention and the busbar module equipped with this locking structure will be briefly summarized and listed below in [1] to [3]. [1] A cantilever-shaped flexible arm (31) that protrudes from an outer surface (28) of a fixing member (bus bar accommodating portion 21) and extends along the outer surface (28) so that a tip end (31 a) faces the fixing direction of a fixed member (bus bar 11); a locking projection (35) that projects from the inner surface of the tip end portion (31a) and locks a locked portion of the fixed member (bus bar 11); Equipped with A locking structure configured so that the engaging protrusion (35) is at a greater distance from an imaginary plane (S) including the outer surface (28) of the fixed member (busbar accommodating portion 21) than from the support point (F) of the flexible arm (31).

[0046] According to the locking structure having the configuration [1] above, the cantilever-shaped flexible arm (31) protrudes from the outer surface (28) of the fixing member (busbar accommodating portion 21), and the tip (31a) extends along the outer surface so as to face the fixing direction of the fixed member (busbar 11). Therefore, the protruding height of the flexible arm (31) from the upper surface of the mounting portion (27) of the fixing member (busbar accommodating portion 21) on which the fixed member (busbar 11) is mounted can be minimized, and the height of the fixing member (busbar accommodating portion 21) can be reduced. Furthermore, when the fixed member (bus bar 11) is fixed to the fixing member (bus bar accommodating portion 21), the flexible arm (31), whose force point (A) against the upper surface (35 a) of the locking projection (35) is located upward (outside the outer surface (28)) from the rising portion (31 b) which is the support point (F), can bend smoothly in the unlocking direction away from the outer surface (28), which is the unlocking direction of the locking projection (35). Furthermore, when a force acts in the lifting direction (direction away from the mounting portion (27)) on the fixed member (bus bar 11) fixed to the fixing member (bus bar accommodating portion 21), the flexible arm (31), whose force point (A) with respect to the locking surface (35 b) of the locking protrusion (35) is located further up the rising direction side (outside the outer surface (28)) than the rising portion (31 b) which is the support point (F), bends in the protruding direction of the locking protrusion (35), which is the locking direction of the locking protrusion (35), thereby improving the holding force on the fixed member (bus bar 11).

[0047] [2] The flexible arm (31) extends in a curved manner from a rising portion (31b) extending from the outer surface (28) of the fixed member (busbar accommodating portion 21) toward the tip end (31a), and has a pair of legs (33, 33) formed by openings formed along the longitudinal direction. The locking structure described in [1] above.

[0048] According to the locking structure having the configuration [2] above, even if the flexural rigidity of the flexible arm (31) is reduced, it is possible to ensure a holding force equivalent to that of the conventional structure. Therefore, the flexural rigidity of the flexible arm (31) is reduced by the pair of legs (33, 33) formed by openings formed along the longitudinal direction, and the elastic repulsive force is reduced. This reduces the insertion force required to fix the fixed member (bus bar 11) to the fixing member (bus bar accommodating portion 21), thereby improving the workability of the insertion operation.

[0049] [3] A busbar module (1) including: an electric wiring body (20) assembled to a battery assembly composed of a plurality of unit cells; and busbars (11) accommodated in a plurality of busbar accommodating portions (21) provided in the electric wiring body (20) and connected to electrodes of the unit cells of the battery assembly, The locking structure according to [1] or [2] above, wherein the fixing member is the bus bar accommodating portion (21) and the fixed member is the bus bar (11), Busbar module (1).

[0050] According to the busbar module (1) having the configuration [3] above, the busbar accommodating section (21) can be made low-profile, and the flexible arm (31) can bend smoothly in the unlocking direction without buckling when the busbar (11) is inserted, thereby improving the holding force for the busbar (11). [Explanation of symbols]

[0051] 11... Bus bar (fixed member) 21... Busbar accommodating portion (fixing member) 28...Outer surface 31...Flexible arm 31a...Tip 35…Latching protrusion F…Support point S...Virtual plane

Claims

1. a cantilever-shaped flexible arm that protrudes from an outer surface of the fixing member and extends along the outer surface so that a tip portion thereof faces the fixing direction of the fixed member; a locking protrusion that protrudes from an inner surface of the tip end portion and locks a locked portion of the fixed member; Equipped with A locking structure configured so that the engaging projection is at a greater distance from an imaginary plane including an outer surface of the fixing member than from a support point of the flexible arm.

2. The flexible arm extends from a rising portion on the outer surface of the fixing member toward the tip portion while curving, and has a pair of legs formed by openings formed along the longitudinal direction. The locking structure according to claim 1 .

3. A bus bar module including: an electric wiring body that is assembled to a battery assembly that is composed of a plurality of unit cells; and bus bars that are housed in a plurality of bus bar housings that are provided on the electric wiring body and are connected to electrodes of the unit cells of the battery assembly, 3. A locking structure according to claim 1, wherein the fixing member is the bus bar accommodating portion and the fixed member is the bus bar. Busbar module.

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