Voltage detection unit

Abstract

A voltage detection unit includes: a voltage detection terminal including a first part and a second part configured to be electrically conductively connected to a detection object; a housing having a plate shape and including a terminal accommodation recess configured to accommodate the voltage detection terminal; a lid configured to engage with the housing at a temporary locking position and a final locking position, at the temporary locking position, the lid does not cover the first part of the voltage detection terminal accommodated in the terminal accommodation recess, and at the final locking position, the lid covers the first part; and a wire conductively connected to the voltage detection terminal at the second part and configured to be led out from the housing when the voltage detection terminal is accommodated in the terminal accommodation recess.

Description

Technical Field

[0001] The subject matter of the present disclosure relates to a voltage detection unit configured such that voltage detection terminals to be conductively connected to a detection object are accommodated in a plate-shaped housing. Background Art

[0002] There has been proposed in the prior art a laminated power storage device in which a plurality of power storage modules are connected in series via conductive plates by alternately arranging and repeatedly laminating thin plate-shaped power storage modules capable of charging and discharging and conductive plates. The power storage modules used in this type of power storage device generally have a structure in which a plurality of battery cells are built in and serve as one battery capable of charging and discharging. In one power storage device in the prior art, in order to monitor the output state of each power storage module (that is, the potential of the output surface of each power storage module with respect to a reference zero potential, hereinafter also simply referred to as "the voltage of the power storage module"), detection terminals such as bus bars are connected to the conductive plates in contact with the output surfaces of the respective power storage modules, and the voltages of the respective power storage modules are measured via the detection terminals (for example, see Patent Document JP2020-161340A).

[0003] When a bus bar or the like is actually connected to the conductive plate in the power storage device having the above structure, since the power storage module or the conductive plate has a thin plate shape, it is difficult to secure a space for providing other components for connection (for example, bolts for bolt fastening). Therefore, in the above power storage device of the prior art, insertion holes into which the detection terminals are inserted are provided in the side edge portions of the conductive plates, and the detection terminals are inserted into the insertion holes of the respective conductive plates from the side of the laminate in which the power storage modules and the conductive plates are laminated, thereby connecting the conductive plates and the detection terminals. However, in the connection method of the prior art, when inserting the detection terminals, since the alignment between the insertion holes of the conductive plates and the detection terminals is complicated, it is difficult to improve the operability of the connection operation. Summary of the Invention

[0004] An exemplary aspect of the subject matter of the present disclosure provides a voltage detection unit having excellent operability for conductive connection to a detection object.

[0005] According to an exemplary aspect of the present disclosure, a voltage detection unit includes: a voltage detection terminal including a first portion and a second portion configured to be conductively connected to an object to be detected; a housing having a plate shape and including a terminal receiving recess configured to receive the voltage detection terminal; a cover configured to engage with the housing at a temporary locking position and a final locking position, at the temporary locking position, the cover does not cover the first portion of the voltage detection terminal received in the terminal receiving recess, and at the final locking position, the cover covers the first portion; and a wire conductively connected to the voltage detection terminal at the second portion and configured to extend from the housing when the voltage detection terminal is received in the terminal receiving recess.

[0006] Other aspects and advantages of the present disclosure will become more apparent from the following description, drawings and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a partially exploded perspective view of a stacked power storage device including a voltage detection unit according to an embodiment of the present disclosure;

[0008] Figure 2A is a sectional view taken along line A-A of Figure 1 and Figure 2B is an enlarged view of part B of Figure 2A ;

[0009] Figure 3 is Figure 1 a partially exploded perspective view of the conductive module shown in

[0010] Figure 4 is Figure 1 an exploded perspective view of a voltage detection unit according to an embodiment of the present disclosure shown in

[0011] Figure 5 is a top view showing the cover and the housing containing the voltage detection terminal and the wire;

[0012] Figure 6 is a bottom view showing the cover and the housing containing the voltage detection terminal and the wire;

[0013] Figure 7A is a top view showing the state where the cover is locked to the housing at the temporary locking position, and Figure 7B is a sectional view taken along line C-C of Figure 7A ;

[0014] Figure 8A is a top view showing the state where the cover is locked to the housing at the final locking position, and Figure 8B is a sectional view taken along line C-C of Figure 8AA sectional view taken along line D-D; and

[0015] Figure 9 is Figure 7B and 8B a sectional view of the housing shown. DETAILED DESCRIPTION

[0016] The voltage detection unit 5 according to embodiments of the present disclosure will be described later with reference to the accompanying drawings. For convenience of description hereinafter, as Figure 1 etc., "front-rear direction", "left-right direction", "up-down direction", "front", "rear", "left", "right", "up", and "down" are defined. The "front-rear direction", "left-right direction", and "up-down direction" are perpendicular to each other. The left-right direction is consistent with the first direction in which the cover is attached to the housing. The front-rear direction is consistent with the second direction in which the electric wire is led out from the housing.

[0017] The voltage detection unit 5 is generally used in the stacked power storage device 1, such as Figure 1 the power storage device shown. The power storage device 1 is formed by alternately stacking rectangular thin-plate-shaped power storage modules 2 capable of charging and discharging and rectangular thin-plate-shaped conductive modules 3 in the up-down direction. The conductive module 3 can electrically connect adjacent power storage modules 2 to each other. In the power storage device 1, a plurality of power storage modules 2 are electrically connected in series via the conductive module 3. The power storage module 2 has a structure in which a plurality of battery cells (not shown) are built in, and the entire power storage module 2 serves as one battery capable of charging and discharging.

[0018] As Figure 1 shown, the conductive module 3 includes: a conductive plate 4 having a rectangular thin-plate shape (the conductive plate 4 also has a function as a heat dissipation part, as described later); a voltage detection unit 5 having a rectangular thin-plate shape, which is connected to the right side of the conductive plate 4; and an opposing unit 6 having a rectangular thin-plate shape, which is connected to the left side of the conductive plate 4, and the entire conductive module 3 is formed into a rectangular thin-plate shape. As Figures 1 to 3 shown (particularly referring to Figure 2A ), the conductive plate 4 and the voltage detection unit 5 are connected to each other by fitting a flange portion 4a provided on the right end surface of the conductive plate 4 and extending in the front-rear direction into a recess 5a provided on the left end surface of the voltage detection unit 5 and extending in the front-rear direction. The conductive plate 4 and the opposing unit 6 are connected to each other by fitting a flange portion 4b provided on the left end surface of the conductive plate 4 and extending in the front-rear direction into a recess 6a provided on the right end surface of the opposing unit 6 and extending in the front-rear direction.

[0019] In each of the conductive modules 3 between the power storage modules 2 adjacent in the up-down direction, the conductive plate 4 is in direct contact with the upper and lower power storage modules 2, as Figure 2AAs shown. Therefore, the conductive plate 4 has the function of electrically connecting the lower surface of the upper power storage module 2 and the upper surface of the lower power storage module 2 to each other, and the function of releasing the heat generated from the upper and lower power storage modules 2 to the outside as a heat dissipation part.

[0020] In each of the conductive modules 3 between the power storage modules 2 adjacent in the vertical direction, the voltage detection unit 5 includes a voltage detection terminal 10 (see Figure 2A and 2B etc.) that is to be in contact with the conductive plate 4 as will be described later. The voltage detection unit 5 has the following function: via a wire 20 (see Figure 1 etc.) connected to the voltage detection terminal 10, it outputs a signal representing the voltage between the upper and lower power storage modules 2 (specifically, the potential of the upper surface (output surface) of the lower power storage module 2 with respect to the reference zero potential). Although the voltage detection unit 5 is provided on the right side of the conductive plate 4 in Figures 1 to 3 , a voltage detection unit having the same function as the voltage detection unit 5 can be provided on the left side of the conductive plate 4. In this case, as the voltage detection unit having the same function as the voltage detection unit 5, a voltage detection unit obtained by flipping the entire structure of the voltage detection unit 5 in the left-right direction (i.e., a symmetric product of the voltage detection unit 5) is used.

[0021] In each of the conductive modules 3 between the power storage modules 2 adjacent in the vertical direction, any one of a voltage detection unit, a dummy unit, or a temperature detection unit is used as the opposing unit 6 according to the specifications of the power storage device 1.

[0022] When the opposing unit 6 is a voltage detection unit, a voltage detection unit obtained by flipping the entire structure of the voltage detection unit 5 in the left-right direction (i.e., the symmetric product of the above voltage detection unit 5) is used as the opposing unit 6. In this case, the voltage detection unit 5 is provided on the right side of the conductive plate 4, and the symmetric product of the voltage detection unit 5 is provided on the left side of the conductive plate 4. The opposing unit 6 (the symmetric product of the voltage detection unit 5) has the same function as the voltage detection unit 5.

[0023] When the opposing unit 6 is a dummy unit, as Figure 3 shown, a simple resin plate having a recess 6a extending in the front-rear direction is used as the opposing unit 6. In this case, the opposing unit 6 only has the function of filling the gap between the upper and lower power storage modules 2.

[0024] When the opposing unit 6 is a temperature detection unit, as Figure 1 shown, the opposing unit 6 has the following structure: a temperature sensor 7 (thermistor) is incorporated into the resin plate used as a dummy unit. In this case, the opposing unit 6 has the following function: via a wire 7a (seeFigure 1 Output a signal indicating the temperature of the power storage module 2 above and below.

[0025] The following will refer to Figures 4 to 9 Describe the specific configuration of the voltage detection unit 5 according to an embodiment of the subject matter of the present disclosure. As Figure 4 shown, the voltage detection unit 5 includes: a housing 40; a voltage detection terminal 10 accommodated in the housing 40; a wire 20 connected to the voltage detection terminal 10 and accommodated in the housing 40; and a cover 30 attached to the housing 40.

[0026] The voltage detection terminal 10 is accommodated in a terminal accommodation recess 42 (see Figure 4 ), which will be described later, formed in the housing 40. The wire 20 is accommodated in a wire accommodation recess 46 (see Figure 4 ), which will be described later, formed in the housing 40. And the cover 30 is attached to a cover attachment recess 41 (see Figure 4 ), which will be described later, formed in the housing 40. The respective components forming the voltage detection unit 5 will be described in sequence later.

[0027] First, the voltage detection terminal 10 will be described. The voltage detection terminal 10 made of metal is formed by performing a process such as pressing on a single metal plate. The voltage detection terminal 10 is accommodated from above in the terminal accommodation recess 42 of the housing 40. As Figure 4 shown, the voltage detection terminal 10 includes: a first portion 11 having a rectangular flat plate shape extending in the front-rear direction; and a second portion 12 having a rectangular flat plate shape extending leftward from the front end portion of the first portion 11, and the voltage detection terminal 10 has a flat plate shape that is generally L-shaped when viewed in the up-down direction.

[0028] One end portion of the wire 20 is fixed to the lower surface of the end portion 11a (i.e., the end portion on the rear end side) of the first portion 11 to be electrically connected thereto (also see Figure 6 ). The other end portion of the wire 20 is connected to a voltage measuring device (not shown) outside the power storage device 1. A part of the flange portion 4a of the conductive plate 4 is fixed to the lower surface of the end portion 12a (i.e., the end portion on the left end side) of the second portion 12 by a technique such as ultrasonic bonding or welding (see Figure 2B ).

[0029] A protruding portion 13 protruding forward is formed at the front edge of the second portion 12. When the voltage detection terminal 10 is accommodated in the housing 40, the protruding portion 13 is locked to a locking groove 45 (see Figure 4 ) formed in the housing 40.

[0030] Next, the cover 30 will be described. The cover 30 is a resin molded product and is attached to the cover attachment recess 41 of the housing 40 from the right side. The cover 30 includes an opposing portion 31 and an extension portion 32 that extends rearward from the opposing portion 31. The opposing portion 31 is mainly used to cover and protect the voltage detection terminal 10, and the extension portion 32 is mainly used to cover and protect the electric wire 20.

[0031] The opposing portion 31 includes: a pair of flat plate portions 33 that have the same shape and face each other with a space therebetween in the vertical direction; and a connecting portion 34 that connects the right end edges of the pair of flat plate portions 33 in the vertical direction over the entire area in the front-rear direction of the right end edges extending in the front-rear direction. The opposing portion 31 has a substantially U-shaped opening to the left when viewed in the front-rear direction. Each flat plate portion 33 includes: a substantially square flat base portion 33a that is connected to the connecting portion 34; and a rectangular flat extension portion 33b that extends leftward from the front end portion of the base portion 33a, and the flat plate portion 33 has a substantially L-shaped as a whole when viewed in the vertical direction. The extension portion 32 extends continuously rearward from the rear end edge of the upper flat plate portion 33 (more specifically, the upper base portion 33a) of the pair of flat plate portions 33 that form the opposing portion 31 and is flush with the rear end edge, and has a substantially rectangular flat plate shape.

[0032] In the extension portion 32, a pair of wire holding pieces 35 extending in the left-right direction are integrally formed and arranged at intervals in the front-rear direction. As can be understood from Figure 6 each wire holding piece 35 projects downward from the lower surface of the extension portion 32, extends in the left-right direction, and further projects leftward from the left end edge of the extension portion 32. When the cover 30 is attached to the housing 40, the wire holding pieces 35 are used to hold the electric wire 20 accommodated in the housing 40.

[0033] At a predetermined position of the lower flat plate portion 33 (more specifically, the lower base portion 33a) of the pair of flat plate portions 33 that form the opposing portion 31, a locking portion 36 that projects upward toward the upper flat plate portion 33 is formed (see Figure 7B and 8B ). The locking portion 36 is used to cooperate with a temporarily locked portion 55 and a finally locked portion 56, which will be described later, provided in the housing 40 to lock the cover 30 to a temporarily locked position (see Figures 7A to 7B and a finally locked position (see Figure 8A and 8B ).

[0034] Next, the housing 40 will be described. The housing 40 is a resin molded product and has a substantially rectangular thin plate shape extending in the front-rear direction, as shown in Figure 1 、 3 and so on. A recess 5a that is recessed to the right and extends in the front-rear direction is formed in the left end surface of the housing 40. The flange portion 4a of the conductive plate 4 is to be fitted into the recess 5a (seeFigure 2A and 2B etc.).

[0035] The lid mounting recess 41 is formed in the portion of the upper and lower surfaces of the housing 40 to which the lid 30 is to be mounted. Each lid mounting recess 41 has a shape corresponding to the overall shape of the lid 30 and is recessed (see Figure 4 ). The recess depth of the lid mounting recess 41 (depth in the vertical direction) is equal to the plate thickness of the lid 30 (opposing portion 31 + extending portion 32). Therefore, when the lid 30 is mounted to the housing 40, the surfaces of the housing 40 and the lid 30 are flush with each other (see Figure 1 , 8A and 8B).

[0036] The terminal receiving recess 42 is formed in the portion of the bottom surface 41a of the lid mounting recess 41 on the upper surface side of the housing 40 for receiving the voltage detection terminal 10 (see Figure 4 ). The terminal receiving recess 42 has a shape corresponding to the overall shape of the voltage detection terminal 10 and is further recessed from the bottom surface 41a of the lid mounting recess 41. The recess depth of the terminal receiving recess 42 (depth in the vertical direction) is equal to the plate thickness of the voltage detection terminal 10. Therefore, when the voltage detection terminal 10 is mounted to the housing 40, the upper surface of the voltage detection terminal 10 and the bottom surface 41a of the lid mounting recess 41 are flush with each other (see Figure 7B and 8B ).

[0037] A cutout 43 that is recessed approximately rectangularly to the right when viewed in the vertical direction is formed at the position of the end portion 12a of the voltage detection terminal 10 to be provided in the left end edge of the housing 40 in the front - rear direction. A recess 5a extending in the front - rear direction on the left end surface of the housing 40 is divided by the cutout 43. When the voltage detection terminal 10 is received in the housing 40, the upper and lower surfaces of the end portion 12a of the voltage detection terminal 10 are exposed through the cutout 43 (see Figure 7B ).

[0038] A through - hole 44 extending in the front - rear direction and penetrating in the vertical direction is formed in the portion of the terminal receiving recess 42 where the end portion 11a of the voltage detection terminal 10 is to be provided. When the voltage detection terminal 10 is received in the housing 40, one end portion (contact) of the wire 20 connected to the voltage detection terminal 10 enters the through - hole 44 (see Figure 6 ). In other words, the through - hole 44 serves as a release portion to avoid interference between the bottom surface 42a of the terminal receiving recess 42 and one end portion of the wire 20.

[0039] A locking groove 45 that is recessed forward and communicates with the recess 5a to correspond to the protruding portion 13 is provided at the protruding portion 13 where the voltage detection terminal 10 is to be placed (see Figure 4is formed at the position of () on the inner wall surface of the terminal receiving recess 42 (see Figure 4 ).

[0040] The wire receiving recess 46 is formed in a portion of the upper surface of the housing 40 that is to receive the wire 20. The wire receiving recess 46 is recessed and has a shape corresponding to the layout form of the wire 20 when the wire 20 is received (see Figure 4 ). The wire receiving recess 46 is a series of groove portions, including: a pair of straight portions 47 that extend in a straight shape extending in the front-rear direction and are provided at intervals in the front-rear direction; and a bent portion 48 that connects the pair of straight portions 47 and extends while being bent to protrude to the right. The front end of the front straight portion 47 of the pair of straight portions 47 communicates with the terminal receiving recess 42, and the rear end of the rear straight portion 47 of the pair of straight portions 47 forms a wire lead-out opening 49, and the wire 20 extends from the rear end edge of the housing 40 through the wire lead-out opening 49. In this way, compared with the case where the wire receiving recess 46 is formed only by the straight portions 47, since the wire receiving recess 46 includes the bent portion 48, even when an unexpected external force is applied to the wire 20 led out from the housing 40, the external force can be resisted by the friction between the bent portion 48 and the wire 20. Therefore, a large external force is less likely to be applied to the contact between the voltage detection terminal 10 and the wire 20.

[0041] Narrow-width recesses 51 are respectively provided in portions near the boundaries between the pair of straight portions 47 and the bent portion 48. The narrow-width recesses 51 are recesses whose respective widths (intervals in the left-right direction) are narrower than the width of the straight portions 47. The width of the narrow-width recesses 51 is slightly smaller than the outer diameter of the wire 20. Therefore, the narrow-width recesses 51 are used to hold the wire 20 while squeezing the wire 20 in the left-right direction. Since the wire 20 is held by the pair of narrow-width recesses 51, even when an unexpected external force is applied to the wire 20 led out from the housing 40, the external force can be resisted by the friction between the narrow-width recesses 51 and the wire 20. Therefore, a large external force is less likely to be applied to the contact between the voltage detection terminal 10 and the wire 20.

[0042] As Figure 4 shown, a pair of wire holding piece recesses 52 that extend in the left-right direction and correspond to the pair of wire holding pieces 35 are formed in the bottom surface 41a of the lid mounting recess 41 on the upper surface side of the housing 40 at the positions of the pair of wire holding pieces 35 where the lid 30 is to be provided, so that the pair of wire holding piece recesses 52 are arranged at intervals in the front-rear direction. The pair of wire holding piece recesses 52 are arranged such that the vertex 48a of the bent portion 48 of the wire receiving recess 46 (see Figure 4 is provided between the pair of wire holding piece recesses 52 in the front-rear direction.

[0043] Each wire holding piece recess 52 extends in the left - right direction on the upper surface of the housing 40 from the right end edge of the housing 40 across the wire receiving recess 46 to the left - hand inner wall 41b of the lid - attaching recess 41 (see Figure 4 ). The receiving holes 53 that are recessed leftward are respectively formed in the portions of the left - hand inner wall 41b of the lid - attaching recess 41 that are connected to a pair of wire holding piece recesses 52 (see Figure 4 ). When the lid 30 is attached to the housing 40, the extending ends (i.e., the left ends) of the pair of wire holding pieces 35 of the lid 30 are inserted and received in the pair of receiving holes 53.

[0044] As Figure 6 shown, on the bottom surface 41a of the lid - attaching recess 41 on the lower - surface side of the housing 40, a contact portion 54, a temporarily locked portion 55, and a finally locked portion 56, which are recesses that are recessed upward, are sequentially formed at positions spaced from right to left at the same positions as those where the locking portion 36 of the lid 30 (see Figure 7B etc.) is provided in the front - rear direction. As Figures 6 to 9 shown (specifically, see Figure 9 ), the contact portion 54 is a recess continuous with the right end edge of the housing 40.

[0045] As Figure 9 shown, the side surface of the contact portion 54 is formed by a second inclined surface 54a, the side surface of the temporarily locked portion 55 is formed by a first inclined surface 55a, and the side surface of the finally locked portion 56 is formed by a vertical surface 56a. The inclination angle (second angle) θa (<90°) of the second inclined surface 54a with respect to the left - right direction is smaller than the inclination angle (first angle) θb (<90°) of the first inclined surface 55a with respect to the left - right direction, and the inclination angle θc of the vertical surface 56a with respect to the left - right direction is approximately 90°. The functions and effects of this magnitude relationship of the inclination angles will be described later. The components forming the voltage detection unit 5 have been described above.

[0046] Next, the steps when the voltage detection terminal 10 and the lid 30 are attached to the housing 40 will be described. First, the voltage detection terminal 10 is received in the terminal receiving recess 42 of the housing 40, where the wire 20 has been previously connected to the voltage detection terminal 10 by a technique such as ultrasonic bonding or welding. Thus, the voltage detection terminal 10 is fitted into the terminal receiving recess 42 of the housing 40 from above, such that the protruding portion 13 enters the locking groove 45, and one end portion (contact point) of the wire 20 enters the through - hole 44. In the state where the accommodation of the voltage detection terminal 10 in the housing 40 is completed, the upper and lower surfaces of the end portion 12a of the voltage detection terminal 10 are exposed via the cutout 43 (see Figure 7B ).

[0047] Next, the wire 20 extending from the voltage detection terminal 10 accommodated in the housing 40 is accommodated in the wire accommodation recess 46 of the housing 40. Accordingly, the wire 20 is fitted from above along the wire accommodation recess 46 formed by the pair of straight portions 47 and the bent portion 48. At this time, the pair of portions of the wire 20 located above the pair of narrow-width recesses 51 are pushed downward, so that the pair of portions of the wire 20 are accommodated in the pair of narrow-width recesses 51. In a state where the accommodation of the wire 20 in the housing 40 is completed, the wire 20 extends rearward from the wire lead-out opening 49 to the outside of the housing 40.

[0048] Next, the cover 30 is attached to the housing 40. Accordingly, the cover 30 is attached to the cover attachment recess 41 of the housing 40 from the right side, so that the opposing portion 31 of the cover 30 sandwiches the cover attachment recess 41 on the upper and lower surfaces of the housing 40 vertically, the extending portion 32 of the cover 30 covers the cover attachment recess 41 on the upper surface side of the housing 40, and the pair of wire holding pieces 35 of the cover 30 cover the pair of wire holding piece recesses 52 of the housing 40.

[0049] In the process of attaching the cover 30 to the housing 40, the locking portion 36 of the cover 30 first comes into contact with the second inclined surface 54a of the contact portion 54 of the housing 40, slides on the second inclined surface 54a while passing over the contact portion 54, and then subsequently enters the inside of the temporarily locked portion 55, so that the locking portion 36 engages with the temporarily locked portion 55 and is pressed against the first inclined surface 55a on the left side of the temporarily locked portion 55 (see Figure 7B ). As a result, the cover 30 is locked to the housing 40 at the temporarily locked position, the attachment of the cover 30 to the housing 40 is completed (see Figures 7A to 7B ), and the voltage detection unit 5 is obtained (see Figure 3 ). As will be described later, the voltage detection unit 5 obtained after the attachment of the cover 30 to the housing 40 (in a state where the cover 30 is locked at the temporarily locked position) is used for assembling the conductive module 3 (see Figure 1 ).

[0050] Here, as described above, the inclination angle θa of the second inclined surface 54a is smaller than the inclination angle θb of the first inclined surface 55a (see Figure 9 ). Therefore, in the process of attaching the cover 30 to the housing 40, the locking portion 36 of the cover 30 can easily pass over the contact portion 54, and the locking portion 36 of the cover 30 comes into contact with the first inclined surface 55a of the temporarily locked portion 55 having an angle larger than that of the second inclined surface 54a, so that the operator can easily recognize that the cover 30 has reached the temporarily locked position. Accordingly, it is possible to prevent the operator from erroneously pushing the cover 30 forward to the final locked position.

[0051] In a state where the cover 30 is locked at the temporarily locked position, as Figure 7AAs shown, the opposing portion 31 of the cover 30 (more specifically, a pair of vertically extending portions 33b) does not cover the end portion 12a of the voltage detection terminal 10. Accordingly, the upper and lower surfaces of the end portion 12a of the voltage detection terminal 10 remain exposed via the cutout 43 (see Figure 7B ).

[0052] In addition, a pair of wire holding pieces 35 of the cover 30 are provided on a part of the opening of the straight portion 47 and the bent portion 48 of the wire accommodation recess 46. As a result, the wire 20 is prevented from coming off from the wire accommodation recess 46. Further, the extending end portions of the pair of wire holding pieces 35 are inserted into the pair of accommodation holes 53. Accordingly, positional deviation of the pair of wire holding pieces 35 and unexpected deformation such as separation of the pair of wire holding pieces 35 from the wire accommodation recess 46 can be prevented. Further, the extending portion 32 of the cover 30 is placed on the opening of the apex 48a of the bent portion 48 of the wire accommodation recess 46. Accordingly, the wire 20 can be prevented from coming off from the wire accommodation recess 46 and being arranged so as to straddle the bent portion 48 (that is, skipping over the bent portion 48). In this way, the possibility of generating a specific problem due to the wire 20 coming out of the bent portion 48 of the wire accommodation recess 46 can be reduced.

[0053] When the cover 30 is further pushed leftward relative to the housing 40 in a state where the cover 30 is locked at the temporary locking position, the extending end portions of the pair of wire holding pieces 35 of the cover 30 further enter and are received in the pair of accommodation holes 53, and the locking portion 36 of the cover 30 crosses over the temporarily locked portion 55 and then enters the inside of the finally locked portion 56 to engage with the finally locked portion 56 (see Figure 8A and 8B ). As a result, the cover 30 is locked to the housing 40 at the final locking position.

[0054] In a state where the cover 30 is locked at the final locking position, since the side surface of the finally locked portion 56 is formed by the vertical surface 56a (θc = approximately 90°), the locking portion 36 of the cover 30 cannot easily cross over the finally locked portion 56. As a result, unexpected positional deviation etc. of the cover 30 in the left - right direction can be prevented.

[0055] In a state where the cover 30 is locked at the final locking position, as Figure 8A and 8B shown, the entire area of the cover attachment recess 41 is covered by the cover 30 such that the entire wire accommodation recess 46 is covered by the extending portion 32 of the cover 30. As a result, the wire 20 is prevented from coming out of the wire accommodation recess 46. Further, as Figure 8A shown, the opposing portion 31 of the cover 30 (more specifically, a pair of vertically extending portions 33b) covers the upper and lower surfaces of the end portion 12a of the voltage detection terminal 10. As a result, the entire voltage detection terminal 10 is covered by the opposing portion 31 of the cover 30, and accordingly, the voltage detection terminal 10 can be reliably protected.

[0056] As described above, the voltage detection unit 5 obtained after the lid 30 is attached to the housing 40 (in a state where the lid 30 is locked in the temporary locking position) is used to assemble the conductive module 3 (see Figure 1 ). Specifically, first, as Figure 3 shown, the flange portion 4a of the conductive plate 4 and the concave portion 5a of the voltage detection unit 5 are engaged with each other so that the voltage detection unit 5 is connected to the right side of the conductive plate 4.

[0057] In this state, as can be understood from Figure 3 and 7B , a part of the flange portion 4a of the conductive plate 4 is provided to overlap with the lower side of the end portion 12a of the voltage detection terminal 10 (see also Figure 2B ). And due to the presence of the notch 43 in the housing 40, the upper surface of the end portion 12a of the voltage detection terminal 10 is exposed upward, and a part of the lower surface of the flange portion 4a of the conductive plate 4 is exposed downward.

[0058] Next, using the upward-exposed upper surface of the end portion 12a of the voltage detection terminal 10 and the downward-exposed lower surface of the flange portion 4a of the conductive plate 4, the end portion 12a of the voltage detection terminal 10 and a part of the flange portion 4a of the conductive plate 4 are fixed to each other by a technique such as ultrasonic bonding or welding. Thereafter, the lid 30 is moved from the temporary locking position to the final locking position, and the assembly of the voltage detection unit 5 and the conductive plate 4 is completed.

[0059] Next, the flange portion 4b of the conductive plate 4 and the concave portion 6a of the opposed unit 6 are engaged with each other so that the opposed unit 6 is connected to the left side of the conductive plate 4 to which the voltage detection unit 5 has already been attached (see Figure 2A etc.). Thus, the assembly of the conductive module 3 is completed.

[0060] The assembled conductive module 3 obtained in this way is used for the assembly of the power storage device 1 shown in Figure 1 . Specifically, the power storage device 1 is obtained by alternately laminating the power storage modules 2 and the conductive modules 3 in the vertical direction and fixing these laminated modules with a predetermined metal fitting or the like.

[0061] As described above, the voltage detection unit 5 according to the present embodiment can accommodate the voltage detection terminal 10 to which the electric wire 20 is connected to the terminal accommodation recess 42 of the housing 40, and the lid 30 can be locked to the housing 40 with the end portion 12a of the voltage detection terminal 10 exposed. When the voltage detection unit 5 is electrically connected to the conductive plate 4 (the conductive plate 4 of the stacked power storage device 1), the exposed end portion 12a of the voltage detection terminal 10 can be fixed to the conductive plate 4 by ultrasonic bonding or welding after the voltage detection unit 5 is attached to the conductive plate 4. In this way, compared with the above connection between the bus bar and the conductive plate in the prior art, the bus bar and the conductive plate can be firmly connected while reducing the contact resistance. Further, after the conductive plate 4 and the voltage detection terminal 10 are connected to each other, the lid 30 is moved from the temporary locking position to the final locking position, so that the end portion 12a of the voltage detection terminal 10 can be covered with the lid 30 to protect the end portion 12a. When the conductive plate 4 to which the voltage detection unit 5 is attached is stacked with the power storage module 2, a power storage device 1 similar to the power storage device in the above prior art can be formed. As described above, the voltage detection unit 5 according to the present embodiment has excellent operability and voltage detection accuracy in the conductive connection with the power storage module 2 of the stacked power storage device 1.

[0062] In addition, when the lid 30 is in the temporary locking position, the wire holding piece 35 of the lid 30 is disposed on the opening of the wire accommodation recess 46, thereby preventing the electric wire 20 from detaching from the wire accommodation recess 46. Similarly, when the lid 30 is in the final locking position, the extension portion 32 of the lid 30 covers the wire accommodation recess 46, thereby preventing the electric wire 20 from detaching from the wire accommodation recess 46. As a result, the state in which the holding wire 20 is properly accommodated in the wire accommodation recess 46 is maintained, and thus the possibility of problems such as difficulty in attaching the lid 30 due to the detachment of the electric wire 20 from the wire accommodation recess 46 can be reduced.

[0063] In addition, when the lid 30 is in the temporary locking position, since the extended end portion of the wire holding piece 35 of the lid 30 enters the accommodation hole 53 of the housing 40, accidental deformation such as the separation of the wire holding piece 35 from the wire accommodation recess 46 can be prevented. In this way, the possibility of problems occurring due to the detachment of the electric wire 20 from the wire accommodation recess 46 can be further reduced.

[0064] In addition, the wire receiving recess 46 of the housing 40 includes a straight portion 47 and a bent portion 48. Therefore, compared with the case where the wire receiving recess 46 is formed only by the straight portion 47, even when an unexpected external force is applied to the wire 20 led out from the housing 40, the external force can be resisted by the friction between the inner wall of the groove of the bent portion 48 and the wire 20. And thus, a large external force is less likely to be applied to the contact point (i.e., the end portion 11a) between the voltage detection terminal 10 and the wire 20. Therefore, the reliability of the electrical connection between the voltage detection terminal 10 and the wire 20 can be improved.

[0065] In addition, when a plurality (two) of wire holding pieces 35 are arranged such that the vertex 48a of the bent portion 48 of the wire receiving recess 46 is disposed between the wire holding pieces 35 and the cover 30 is in the temporarily locked position, the extension portion 32 of the cover 30 is disposed on the opening of the vertex 48a of the bent portion 48 of the wire receiving recess 46, so that the possibility can be further reduced that problems occur due to the loss of the original function of the bent portion 48 caused by the wire 20 coming out of the wire receiving recess 46 and being laid out to skip over the bent portion 48 (i.e., bypass the bent portion 48).

[0066] In addition, when the cover 30 moves from the outside of the housing 40 to the temporarily locked position, the locking portion 36 of the cover 30 that contacts the second inclined surface 54a of the contact portion 54 of the housing 40 easily crosses over the contact portion 54, and the locking portion 36 of the cover 30 is pressed against the first inclined surface 55a of the temporarily locked portion 55 of the housing 40, so that the cover is disposed in the temporarily locked position. Since the inclination angle θa of the second inclined surface 54a of the contact portion 54 is smaller than the inclination angle θb of the first inclined surface 55a of the temporarily locked portion 55, the locking portion 36 of the cover 30 can easily cross over the contact portion 54, and the locking portion 36 of the cover 30 contacts the first inclined surface 55a with a larger angle of the temporarily locked portion 55, so that the operator can easily recognize that the cover 30 has reached the temporarily locked position. When the cover 30 moves to the final locked position, the locking portion 36 of the cover 30 engages with the final locked portion 56 of the housing 40, thereby preventing accidental position displacement of the cover 30 and the like.

[0067] Although the subject matter of the present disclosure has been described with reference to specific exemplary embodiments, the scope of the subject matter of the present disclosure is not limited to the above exemplary embodiments, and those skilled in the art will understand that various changes and modifications can be made to the present disclosure without departing from the scope of the subject matter of the present disclosure defined by the appended claims.

[0068] In the above embodiment, the cover 30 is provided with a pair of wire holding pieces 35. However, the cover 30 may be provided with one wire holding piece 35, three or more wire holding pieces 35, or no wire holding piece 35.

[0069] According to one aspect of the above-described embodiment, the voltage detection unit (5) includes: a voltage detection terminal (10) including a first part and a second part, the first part being configured to be conductively connected to a detection object; a housing (40) having a plate shape and including a terminal accommodation recess (42) configured to accommodate the voltage detection terminal (10); a lid (30) configured to engage with the housing (40) at a temporary locking position and a final locking position, at the temporary locking position, the lid (30) does not cover the first part of the voltage detection terminal (10) accommodated in the terminal accommodation recess (42), and at the final locking position, the lid (30) covers the first part; and a wire (20) conductively connected to the voltage detection terminal at the second part and configured to be led out from the housing (40) when the voltage detection terminal (10) is accommodated in the terminal accommodation recess (42).

[0070] According to the voltage detection unit having the above-described configuration, the voltage detection terminal to which the wire is connected at the second part can be accommodated in the terminal accommodation recess of the housing, and the lid can be locked to the housing with the first part of the voltage detection terminal exposed. Thus, when the voltage detection unit is electrically connected to a detection object (e.g., a conductive plate of a stacked power storage device), the exposed first part of the voltage detection terminal can be fixed to the detection object by a technique such as ultrasonic bonding or welding, for example, after the voltage detection unit is attached to the detection object. As a result, compared with typical bolt fastening or the like, the need for other connecting components can be eliminated, and compared with the connection methods in the above-described prior art, the alignment of the voltage detection terminal with the detection object can be facilitated and the contact resistance at the contact point can be reduced. Further, after the detection object and the voltage detection terminal are connected to each other, the lid is moved from the temporary locking position to the final locking position so that the first part of the voltage detection terminal (i.e., the contact point between the detection object and the voltage detection terminal) can be covered by the lid to protect the first part. When power storage modules are stacked in which the voltage detection unit is attached to a conductive plate as a detection object, the stacked power storage device as described above can be manufactured. As described above, the voltage detection unit of this configuration has excellent operability in the conductive connection with the detection object. In addition, since it is less likely that a contact resistance deviation occurs at the contact point between the detection object and the voltage detection terminal due to manufacturing tolerances of the detection object and the voltage detection terminal, the voltage detection accuracy of the voltage detection unit of this configuration is more excellent than that of the above-described prior art power storage device.

[0071] The housing (40) may further include a wire receiving recess (46) configured to receive a wire (20). The cover (30) may include: a main body portion configured to cover the wire receiving recess (46) when the cover (30) is in the final locked position; and a wire holding piece (35) protruding from the main body portion in a first direction in which the cover (30) moves from the temporary locked position to the final locked position and configured to be disposed above an opening of the wire receiving recess (46) when the cover (30) is in the temporary locked position).

[0072] With such a configuration, when the cover is in the temporary locked position, the wire holding piece extending from the main body portion of the cover is disposed above the opening of the wire receiving recess, so that the wire is prevented from coming out of the wire receiving recess. Similarly, when the cover is in the final locked position, the main body portion of the cover covers the wire receiving recess, thereby preventing the wire from coming out of the wire receiving recess. Therefore, regardless of whether the cover is in the temporary locked position or the final locked position, the wire is maintained in a state of being properly received in the wire receiving recess. Accordingly, the possibility of a problem occurring in which it is difficult to attach the cover due to the wire coming out of the wire receiving recess can be reduced.

[0073] The housing (40) may further include a receiving hole (53) configured to receive an end portion of the wire holding piece (35) in a first direction when the cover (30) is in the temporary locked position and further receive the wire holding piece (35) when the cover (30) is in the final locked position.

[0074] With such a configuration, when the cover is in the temporary locked position, since the extending end portion of the wire holding piece of the cover enters the receiving hole of the housing, the occurrence of position deviation and deformation of the wire holding piece itself can be prevented. Accordingly, the possibility of a problem occurring due to the wire coming out of the wire receiving recess can be further reduced.

[0075] The wire receiving recess (46) may include: a straight portion (47) configured to guide the wire (20) along a second direction defined by a straight line connecting a second portion of the voltage detection terminal (10) received in the terminal receiving recess (42) to a wire lead-out opening (49) of the housing (40); and a bent portion (48) configured to guide the wire (20) such that the wire (20) is convexly bent with respect to the second direction. When the cover (30) is in the temporary locked position, the wire holding piece (35) may be disposed above an opening of the bent portion (48).

[0076] With this configuration, the wire receiving recess of the housing includes a straight portion and a bent portion. Therefore, compared with the case where the wire receiving recess is formed only by the straight portion, even when an unexpected external force is applied to the wire led out from the housing, the external force can be resisted by the friction between the inner wall of the groove of the bent portion and the wire, so that the external force is less likely to be directly applied to the contact (i.e., the second part) between the voltage detection terminal and the wire. Therefore, the reliability of the electrical connection between the voltage detection terminal and the wire can be improved.

[0077] The wire holding pieces (35) may be a plurality of wire holding pieces (35), and the plurality of wire holding pieces are arranged such that the vertex (48a) of the bent portion (48) is arranged between the respective wire holding pieces of the plurality of wire holding pieces in the second direction. When the lid (30) is in the temporarily locked position, the main body portion may be arranged above the opening of the vertex (48a).

[0078] With such a configuration, when a plurality of (for example, two) wire holding pieces are arranged to sandwich the vertex of the bent portion of the wire receiving recess and the lid is in the temporarily locked position, the main body portion of the lid is arranged on the opening of the vertex of the bent portion of the wire receiving recess. As a result, in particular, it is possible to prevent the loss of the original function of the bent portion due to the wire coming out of the wire receiving recess and being laid across the bent portion (i.e., skipping over the bent portion). Therefore, the possibility of specific problems occurring due to the wire coming out of the bent portion of the wire receiving recess can be reduced.

[0079] The lid (30) may further include a locking portion (36), and the lid (30) engages with the housing (40) at this locking portion. The housing (40) may further include: a temporarily locked portion (55) configured to engage with the locking portion (36) when the lid (30) is in the temporarily locked position; a finally locked portion (56) configured to engage with the locking portion (36) when the lid (30) is in the finally locked position; and a contact portion (54) configured to contact the locking portion (36) before the lid (30) reaches the temporarily locked position by moving in the first direction. The temporarily locked portion (55) may include a first inclined surface (55a) inclined at a first angle (θb) with respect to the first direction, and the contact portion (54) may include a second inclined surface (54a) inclined at a second angle (θa) smaller than the first angle (θb) with respect to the first direction.

[0080] With such a configuration, when the lid moves from the outside of the housing to the temporary locking position, the locking portion of the lid that contacts the inclined surface of the contact portion of the housing can easily pass over the contact portion. Subsequently, the locking portion of the lid presses against the inclined surface of the temporarily locked portion of the housing, causing the lid to be locked in the temporary locking position. Here, since the inclination angle of the inclined surface of the contact portion (i.e., the second angle) is smaller than the inclination angle of the inclined surface of the temporarily locked portion (i.e., the first angle), the lid can pass through the contact portion relatively easily. In addition, since the locking portion of the lid contacts the inclined surface of the temporarily locked portion with a larger angle, the operator can easily identify that the lid has reached the temporary locking position. That is, it is possible to prevent the operator from erroneously pushing the lid forward to the final locking position. When the lid moves to the final locking position after the detection object and the voltage detection terminal are connected to each other, the locking portion of the lid engages with the final locked portion of the housing, thereby preventing accidental position deviation of the lid and the like. In this way, according to the voltage detection unit of the present structure, the operability of assembling the lid to the housing can be improved.

Claims

1. A voltage detection unit, comprising: a plate-shaped voltage detection terminal, which includes a first plate-shaped portion and a second plate-shaped portion, and the first plate-shaped portion is configured to be conductively connected to an object to be detected; a housing, which is plate-shaped and includes a terminal accommodation recess configured to accommodate the voltage detection terminal; a cover configured to engage with the housing at a temporary locking position and a final locking position. At the temporary locking position, the cover does not cover the first plate-shaped portion of the voltage detection terminal accommodated in the terminal accommodation recess, and at the final locking position, the cover covers the first plate-shaped portion; and a wire, which is conductively connected to the voltage detection terminal at the second plate-shaped portion and is configured to lead out from the housing when the voltage detection terminal is accommodated in the terminal accommodation recess.

2. The voltage detection unit according to claim 1, wherein the housing further includes a wire accommodation recess configured to accommodate the wire, and wherein the cover includes: a main body portion configured to cover the wire accommodation recess when the cover is in the final locking position; and a wire holding piece protruding from the main body portion in a first direction in which the cover moves from the temporary locking position to the final locking position, and configured to be disposed above an opening of the wire accommodation recess when the cover is in the temporary locking position.

3. The voltage detection unit according to claim 2, wherein the housing further includes a receiving hole configured to receive an end portion of the wire holding piece in the first direction when the cover is in the temporary locking position, and further receive the wire holding piece when the cover is in the final locking position.

4. The voltage detection unit according to claim 2, wherein the wire accommodation recess includes: a straight portion configured to guide the wire along a second direction defined by a straight line connecting the second plate-shaped portion of the voltage detection terminal accommodated in the terminal accommodation recess and a wire lead-out opening of the housing; and a bent portion configured to guide the wire such that the wire is convexly bent with respect to the second direction, and wherein when the cover is in the temporary locking position, the wire holding piece is disposed above an opening of the bent portion.

5. The voltage detection unit according to claim 3, wherein the wire accommodation recess includes: a straight portion configured to guide the wire along a second direction defined by a straight line connecting the second plate-shaped portion of the voltage detection terminal accommodated in the terminal accommodation recess and a wire lead-out opening of the housing; and a bent portion configured to guide the wire such that the wire is convexly bent with respect to the second direction, and Wherein, when the lid is in the temporary locking position, the wire holding piece is disposed above the opening of the bent portion.

6. The voltage detection unit according to claim 4, wherein, the wire holding piece is a plurality of wire holding pieces, and the plurality of wire holding pieces are arranged such that the vertex of the bent portion is disposed between each of the plurality of wire holding pieces in the second direction, and wherein, when the lid is in the temporary locking position, the main body portion is disposed above the opening of the vertex.

7. The voltage detection unit according to claim 5, wherein, the wire holding piece is a plurality of wire holding pieces, and the plurality of wire holding pieces are arranged such that the vertex of the bent portion is disposed between each of the plurality of wire holding pieces in the second direction, and wherein, when the lid is in the temporary locking position, the main body portion is disposed above the opening of the vertex.

8. The voltage detection unit according to any one of claims 2 to 7, wherein, the lid further includes a locking portion, and the lid is engaged with the housing at the locking portion, wherein the housing further includes: a temporarily locked portion configured to be engaged with the locking portion when the lid is in the temporary locking position; a finally locked portion configured to be engaged with the locking portion when the lid is in the final locking position; and a contact portion configured to contact the locking portion before the lid reaches the temporary locking position by moving in the first direction, wherein the temporarily locked portion includes a first inclined surface that is inclined at a first angle with respect to the first direction, and wherein the contact portion includes a second inclined surface that is inclined at a second angle smaller than the first angle with respect to the first direction.

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