Busbar holder and battery module

Abstract

To makes it easier to clamp a bus bar without strain.SOLUTION: A bus bar holder is attached to a cell stack. The cell stack includes a plurality of battery cells lined up in the X direction. Each of the battery cells includes a tab lead protruding in the Y direction. The bus bar holder is configured as follows when viewed in an attached state when the bus bar holder is attached to the cell stack. The bus bar holder includes a plurality of insertion receiving portions lined up in the X direction, through which the tab leads can be inserted in the Y direction. The bus bar for electrically connecting the tab leads is held between the insertion receiving portions in the bus bar holder so as to be movable relative to the bus bar holder in the X direction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a bus bar holder and a battery module including the same. [Background technology]

[0002] In recent years, electric vehicles such as EVs and HEVs have become increasingly popular in order to reduce carbon dioxide emissions and thereby mitigate adverse effects on the global environment. Some batteries installed in electric vehicles and the like include a cell stack in which multiple battery cells are arranged in the X direction. Each battery cell has a tab lead that protrudes in the Y direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-148244 Summary of the Invention [Problem to be solved by the invention]

[0004] The inventors came up with the idea of ​​electrically connecting the tab leads in such a cell stack as follows: First, a bus bar holder that holds multiple bus bars arranged in the X direction is attached to the Y direction end of the cell stack. This positions the bus bars between the tab leads. Then, the bus bars are clamped together with the adjacent tab leads. In this state, the tab leads are welded to the bus bars.

[0005] However, the inventors have noticed that these cases have the following problem: Battery cells have a certain tolerance in the X direction, which is the thickness direction of the battery cells. Therefore, when multiple battery cells are stacked in the X direction, the position of each battery cell relative to the bus bar holder may be shifted in the X direction from the desired position. This makes it difficult to clamp each bus bar, which may cause problems in the joint between the tab lead and the bus bar.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to make it easier to clamp a bus bar without strain. [Means for solving the problem]

[0007] The inventors discovered that the above object can be achieved by holding a bus bar so that the bus bar can move relative to the bus bar holder in the X direction, and arrived at the present invention. The present invention relates to the following bus bar holders (1) to (4) and battery module (5).

[0008] (1) A bus bar holder attached to a cell stack including a plurality of battery cells arranged in a predetermined X direction, the battery cells including tab leads protruding in a Y direction perpendicular to the X direction, When the bus bar holder is attached to the cell stack, as viewed in an attachment state, a plurality of insertion portions into which the tab leads can be inserted in the Y direction are formed and aligned in the X direction; a bus bar for electrically connecting the tab leads to each other is held between the insertion portions so as to be movable in the X direction relative to the bus bar holder; Busbar holder.

[0009] According to this configuration, by inserting multiple tab leads into multiple insertion portions and attaching a bus bar holder to the cell stack, the bus bar is arranged between the tab leads so that it can move in the X direction. From this state, by clamping the bus bar together with the tab leads adjacent to it on both sides, the bus bar moves to an appropriate position in the X direction. This appropriate position is, for example, a position where the clamping force from both sides in the X direction is equal. Furthermore, the tab leads adjacent to the bus bar on both sides bend in response to the movement of the bus bar. As described above, this configuration makes it easy to clamp the bus bar without any strain.

[0010] (2) When viewed in the above-mentioned mounting state, The bus bar has a long hole formed therein, the long hole extending in the X direction. a predetermined holding pin provided on the bus bar holder is inserted through the elongated hole in the Y direction, thereby holding the bus bar so as to be movable relative to the bus bar holder in the X direction; The bus bar holder according to (1) above.

[0011] According to this configuration, the bus bar can be held so as to be movable relative to the bus bar holder in the X direction with a simple configuration of a holding pin and an elongated hole.

[0012] (3) When viewed in the above-mentioned mounting state, the bus bar extends in a Z direction perpendicular to the X direction and the Y direction, the elongated hole is provided in a middle portion of the bus bar in the Z direction, and the bus bar is held by the bus bar holder so as to be rotatable about the holding pin. The bus bar holder according to (2) above.

[0013] According to this configuration, by making the bus bar rotatable around the holding pin, it is possible to accommodate misalignment of the bus bar relative to the tab lead in the rotation direction.

[0014] (4) When viewed in the mounting state, The bus bar is provided with a protruding portion that protrudes in the Y direction, a positioning recess formed in a holder gripping tool that grips the bus bar holder engages with the protrusion, thereby positioning the bus bar in the X direction with respect to the holder gripping tool and the bus bar holder. The bus bar holder according to any one of (1) to (3) above.

[0015] In the step of attaching the busbar holder to the cell stack, which is prior to the step of clamping the busbar, it is preferable that the busbar be positioned in the X direction relative to the busbar holder from the viewpoint of work efficiency, etc. In this regard, with this configuration, the busbar can be positioned in the X direction relative to the busbar holder by engaging the positioning recess of the holder gripping tool with the protrusion of the busbar.

[0016] (5) A battery module including the bus bar holder according to any one of (1) to (4) and the cell stack, the bus bar holder is attached to the cell stack, and the tab lead is joined to the adjacent bus bar, thereby positioning the bus bar in the X direction with respect to the cell stack and the bus bar holder. Battery module.

[0017] In the battery module, it is preferable that the busbars do not move relative to the cell stack and busbar holder. In this regard, with this configuration, the busbars can be positioned in the X direction relative to the cell stack and busbar holder simply by attaching the busbar holder to the cell stack and joining the tab leads to adjacent busbars. [Effects of the Invention]

[0018] As described above, the configuration (1) makes it possible to easily clamp the bus bar without strain. Furthermore, the configurations (2) to (5) that use the configuration (1) provide additional effects. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a plan cross-sectional view showing a bus bar holder mounting device and its periphery according to a first embodiment. [Figure 2] FIG. 2 is a perspective view showing a cell stack and a bus bar holder. [Figure 3] FIG. [Figure 4] FIG. 2 is a perspective view showing a bus bar holder and a holder gripping tool. [Figure 5] FIG. 5 is an enlarged view of a part of FIG. 4, and in detail is a perspective view showing the positioning recess and its periphery of the first embodiment. [Figure 6] FIG. 10 is a perspective view showing a positioning recess and its periphery in a second embodiment. [Figure 7] FIG. [Figure 8] FIG. 2 is a plan view showing a cell stack. [Figure 9] FIG. 10 is a cross-sectional plan view showing an initial step of attaching a bus bar holder to a cell stack. [Figure 10] FIG. 10 is a cross-sectional plan view showing the subsequent step. [Figure 11] FIG. 10 is a cross-sectional plan view showing the subsequent step. [Figure 12] FIG. 10 is a cross-sectional plan view showing the subsequent step. [Figure 13] FIG. 10 is a cross-sectional plan view showing the subsequent step. [Figure 14] FIG. 10 is a cross-sectional plan view showing a state in which a bus bar holder is attached to a cell stack. [Figure 15] FIG. 10 is a cross-sectional plan view showing a state in which the bus bar holder is released from the holder gripping tool. [Figure 16] FIG. 10 is a cross-sectional plan view showing a state in which two bus bar holders are attached to a cell stack. [Figure 17] FIG. 2 is a plan cross-sectional view showing the bus bar clamp device and its surroundings. [Figure 18] FIG. 2 is a front view showing the bus bar clamp device. [Figure 19] FIG. 10 is a plan cross-sectional view showing a state in which odd-numbered bus bars are clamped. [Figure 20] FIG. 10 is a plan cross-sectional view showing a state in which even-numbered bus bars are clamped. [Figure 21] FIG. 10 is a cross-sectional plan view showing an initial step in clamping the bus bar. [Figure 22] FIG. 10 is a cross-sectional plan view showing the subsequent step. [Figure 23] FIG. 10 is a cross-sectional plan view showing the subsequent step. [Figure 24] FIG. 10 is a cross-sectional plan view showing the subsequent step. [Figure 25] FIG. 10 is a cross-sectional plan view showing the subsequent step. [Figure 26] FIG. 10 is a cross-sectional plan view showing a state in which each tab lead is welded to an adjacent bus bar at the X+ side portion of the Y- side end of the cell stack. [Figure 27] FIG. 10 is a cross-sectional plan view showing a state in which each tab lead is welded to an adjacent bus bar at both ends in the Y direction of the cell stack. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments and can be appropriately modified and implemented within the scope of the present invention.

[0021] [First embodiment] This embodiment relates to a technique for installing two bus bar holders 20a, 20b shown in Fig. 27 on a cell stack 10 shown in Fig. 8 using a holder installation device 50 shown in Fig. 1 and a clamp device 70 shown in Fig. 17. Note that "holder installation device" is an abbreviation for "bus bar holder installation device," and "clamp device" is an abbreviation for "bus bar clamp device." As shown in Fig. 27, the cell stack 10 and each of the bus bar holders 20a, 20b each constitute a part of a battery module 30.

[0022] Hereinafter, as shown in FIG. 2, three predetermined directions that are orthogonal to each other with respect to the cell stack 10 are referred to as the "X direction," "Y direction," and "Z direction." One side in the X direction is referred to as the "X-side," and the opposite side is referred to as the "X+" side. One side in the Y direction is referred to as the "Y-side," and the opposite side is referred to as the "Y+ side." One side in the Z direction is referred to as the "Z-side," and the opposite side is referred to as the "Z+ side."

[0023] In this embodiment, the Z direction is the vertical direction, and the X and Y directions are horizontal directions. However, instead of this, the X or Y direction may be the vertical direction, and the remaining two directions may be horizontal. Also, one of the X, Y, and Z directions may be a direction oblique to the vertical direction, and the remaining two directions may be directions perpendicular to the oblique direction.

[0024] First, a description will be given of the cell stack 10 shown in Fig. 2. The cell stack 10 includes a housing 12 and a plurality of battery cells 15.

[0025] The housing 12 includes a Z+ side plate 125, a Z- side side plate 126, an X- side end plate 121, a center plate 122, and an X+ side end plate 123.

[0026] Z+ side side plate 125 extends in the X and Y directions. Z- side side plate 126 extends in the X and Y directions on the Z- side further than Z+ side plate 125. Hereinafter, Z+ side plate 125 and Z- side side plate 126 will be referred to as two side plates 125, 126.

[0027] The negative X-side end plate 121 extends in the Y and Z directions and connects the negative X-side ends of the two side plates 125, 126. The center plate 122 extends in the Y and Z directions and connects the middle portions of the two side plates 125, 126 in the X direction. The positive X-side end plate 123 extends in the Y and Z directions and connects the positive X-side ends of the two side plates 125, 126.

[0028] Battery cells 15 extending in the Y and Z directions are arranged in the X direction and stored inside the housing 12. Specifically, half of the battery cells 15 are stored between the X-side end plate 121 and the center plate 122. On the other hand, the other half of the battery cells 15 are stored between the center plate 122 and the X+ side end plate 123.

[0029] 8, each battery cell 15 includes a cell body 152, Y+-side tab leads P, N protruding from the Y+-side end of the cell body 152 to the Y+ side, and Y-side tab leads N, P protruding from the Y-side end of the cell body 152 to the Y- side. In each battery cell 15, one of the two tab leads P, N on the Y+ side and the Y- side is the positive-side tab lead P, and the other is the negative-side tab lead N.

[0030] Hereinafter, the arrangement of the battery cells 15 in which the positive electrode side tab lead P is arranged on the Y+ side and the negative electrode side tab lead N is arranged on the Y- side will be referred to as the "positive-negative arrangement." Also, the arrangement of the battery cells 15 in which the negative electrode side tab lead N is arranged on the Y+ side and the positive electrode side tab lead P is arranged on the Y- side will be referred to as the "negative-positive arrangement."

[0031] In the cell stack 10, the battery cells 15 in a positive-negative arrangement and the battery cells 15 in a negative-positive arrangement are arranged alternately in the X direction. Specifically, the battery cell 15 closest to the X- side is in a positive-negative arrangement. The battery cell 15 adjacent to the center plate 122 from the X- side is in a negative-positive arrangement. The battery cell 15 adjacent to the center plate 122 from the X+ side is in a positive-negative arrangement. The battery cell 15 closest to the X+ side is in a negative-positive arrangement.

[0032] As a result of the above, at the Y+ side end of the cell stack 10 and the Y- side end of the cell stack 10, the positive electrode side tab leads P and the negative electrode side tab leads N are arranged alternately in the X direction.

[0033] Next, the two bus bar holders 20a, 20b shown in Fig. 16 will be described. The two bus bar holders 20a, 20b consist of a first bus bar holder 20a and a second bus bar holder 20b. The first bus bar holder 20a is attached to the end of the cell stack 10 on the Y- side. The second bus bar holder 20b is attached to the end of the cell stack 10 on the Y+ side.

[0034] Hereinafter, the state in which the first bus bar holder 20a is attached to the Y- side end of the cell stack 10 will be referred to as the "first attachment state." Furthermore, the state in which the second bus bar holder 20b is attached to the Y+ side end of the cell stack 10 will be referred to as the "second attachment state." Furthermore, the first attachment state and the second attachment state will be referred to as the "attachment state." Furthermore, below, odd-numbered positions from the X+ side to the X- side will be simply referred to as "odd-numbered positions," and even-numbered positions from the X+ side to the X- side will be simply referred to as "even-numbered positions."

[0035] First, a description will be given of the first bus bar holder 20a shown in Fig. 1. The first bus bar holder 20a is configured as follows when viewed in the first mounting state.

[0036] As shown in Fig. 2, the first bus bar holder 20a extends in the X and Z directions. As shown in Fig. 3, the first bus bar holder 20a has insertion holes 22 extending in the Z direction formed side by side at intervals in the X direction. These insertion holes 22 are elongated holes for inserting the tab leads N, P. Note that the "insertion holes 22" may be read as "insertion portions."

[0037] A bus bar 27 at the positive end is held on the X+ side of the insertion hole 22 on the X+ side. The bus bar 27 at the positive end is a conductor for connecting the positive electrode tab lead P of the battery cell 15 on the positive side to the positive electrode terminal of the entire battery module 30. The bus bar 27 at the positive end extends in the Z direction and also extends from the end on the Z+ side toward the X- side.

[0038] Except for one location in the center in the X direction, a normal-width bus bar 25 is held between each even-numbered insertion hole 22 and the adjacent insertion hole 22 on the X-side. Each normal-width bus bar 25 is a conductor for electrically connecting the negative-electrode tab lead N of the even-numbered battery cell 15 to the positive-electrode tab lead P of the adjacent battery cell 15 on the X-side, and extends in the Z direction.

[0039] Meanwhile, a central bus bar 26 is held at one location in the center in the X direction. The central bus bar 26 is a conductor that electrically connects the negative electrode tab lead N of the battery cell 15 adjacent to the center plate 122 from the X+ side to the positive electrode tab lead P of the battery cell 15 adjacent to the center plate 122 from the X- side, and extends in the Z direction.

[0040] The bus bar 28 at the negative end is held on the X- side of the insertion hole 22 at the X- side. The bus bar 28 at the negative end is a conductor for connecting the negative electrode tab lead N of the battery cell 15 at the negative side to the negative electrode terminal of the entire battery module 30. The bus bar 28 at the negative end extends in the Z direction and also extends from the end on the Z+ side toward the X+ side.

[0041] Hereinafter, the center bus bar 26, the positive end bus bar 27, and the negative end bus bar 28 will be referred to as the "special width bus bars 26-28." The X-direction width of each of the special width bus bars 26-28 will be greater than the X-direction width of the normal width bus bar 25. Hereinafter, the normal width bus bar 25 and the special width bus bars 26-28 will be referred to as the "bus bars 25-28." Furthermore, even when describing each of the bus bars 25-28, if bus bar 25 is used as an example, it will be referred to as the "bus bar 25" as appropriate. This also applies when describing several predetermined bus bars as an example.

[0042] As shown in FIG. 3, the first busbar holder 20a has a retaining pin 23 for each of the busbars 25 to 28. Each retaining pin 23 protrudes toward the Y-side. An elongated hole 253 extending in the X-direction is formed in the middle of each of the busbars 25 to 28 in the Z-direction. By inserting the retaining pin 23 into the elongated hole 253, the busbar 25 is held so that it can move in the X-direction relative to the first busbar holder 20a within the range of the elongated hole 253 and can rotate around the retaining pin 23 as an axis. A restricting structure 252 is provided between the first busbar holder 20a and each of the busbars 25 to 28 to restrict the rotation range of the busbar 25 to 28 around the retaining pin 23 as an axis.

[0043] As shown in Fig. 5, at least one end in the Z direction of each of bus bars 25 to 28 is provided with a pair of protrusions 255. Therefore, for example, as shown in Fig. 4, a pair of protrusions 255 may be provided at each end of bus bar 25 in the Z direction, or a pair of protrusions 255 may be provided at only one end in the Z direction of bus bar 25. The pair of protrusions 255 are spaced apart from each other in the X direction and each protrudes toward the Y-side. The role of protrusions 255 will be described later.

[0044] As mentioned above, the above description is of the first bus bar holder 20a when viewed in the first mounting state.

[0045] Next, the second bus bar holder 20b shown in Fig. 16 will be described. The second bus bar holder 20b will be described mainly focusing on the differences from the first bus bar holder 20a, and descriptions of the same or similar aspects as the first bus bar holder 20a will be omitted as appropriate.

[0046] The second bus bar holder 20b holds only a plurality of normal-width bus bars 25. Each normal-width bus bar 25 electrically connects the negative electrode tab lead N of an odd-numbered battery cell 15 to the positive electrode tab lead P of the battery cell 15 adjacent to it on the X-side.

[0047] Hereinafter, even when describing each of the bus bar holders 20a and 20b, if the first bus bar holder 20a is used as an example, it will be referred to as "bus bar holder 20a" as appropriate.

[0048] Next, the holder mounting device 50 shown in Fig. 1 will be described. The holder mounting device 50 is configured so that a first bus bar holder 20a can be mounted to the Y- side end of the cell stack 10. The holder mounting device 50 is also configured so that a second bus bar holder 20b can be mounted to the Y+ side end of the cell stack 10. When viewed in the first mounting state, the holder mounting device 50 is configured as follows:

[0049] The holder attachment device 50 includes two comb-tooth jigs 51 a and 51 b, a comb-tooth driving device 52 , a holder gripping tool 53 , a gripping tool driving device 54 , and a control device 59 .

[0050] 7, the two comb-tooth jigs 51a, 51b consist of a Z+-side comb-tooth jig 51a and a Z-side comb-tooth jig 51b. The Z+-side comb-tooth jig 51a is disposed above the multiple tab leads N, P on the Y-side of the cell stack 10. The Z-side comb-tooth jig 51b is disposed below the multiple tab leads N, P on the Y-side of the cell stack 10.

[0051] Each of the comb tooth jigs 51a and 51b is comb-shaped and includes comb teeth 515 extending in the Z direction and connecting portions 512 connecting the base ends of the comb teeth 515. The Z+-side comb tooth jig 51a is divided into an X+-side portion 51a1 and an X-side portion 51a2, and the distance in the X direction between the X+-side portion 51a1 and the X-side portion 51a2 is adjustable. Similarly, the Z-side comb tooth jig 51b is divided into an X+-side portion 51b1 and an X-side portion 51b2, and the distance in the X direction between the X+-side portion 51b1 and the X-side portion 51b2 is adjustable. The Z+-side comb tooth jig 51a has the tips of each comb tooth 515 facing the Z-side. On the other hand, the Z-side comb tooth jig 51b has the tips of each comb tooth 515 facing the Z+ side.

[0052] The comb-tooth driving device 52 shown in FIG. 1 is configured to be able to drive two comb-tooth jigs 51a and 51b in the Z direction.

[0053] The holder gripper 53 shown in FIG. 1 is configured to be able to grip the first busbar holder 20a from the Y-side. As shown in FIG. 4, a plurality of positioning recesses 535 recessed toward the Y-side are formed in predetermined locations of the holder gripper 53 and aligned in the X-direction. The inner circumferential surfaces of the positioning recesses 535 engage with the protrusions 255 of the busbars 25-28, thereby positioning the busbars 25-28 in the X-direction relative to the holder gripper 53 and the first busbar holder 20a. That is, for example, as shown in FIG. 4, if a pair of protrusions 255 is provided at each end of the busbar 25 in the Z-direction, the busbars 25-28 are positioned in the X-direction relative to the holder gripper 53 and the first busbar holder 20a at those ends. A specific aspect of the positioning recesses 535 may be, for example, a first aspect shown in FIG. 5 or a second aspect shown in FIG. 6.

[0054] 5 , both side surfaces of the pair of protrusions 255 abut against the inner surfaces of the positioning recess 535, thereby positioning the bus bar 25 in the X direction with respect to the holder gripper 53. Furthermore, the tip surfaces of the pair of protrusions 255 abut against the bottom surface of the positioning recess 535, thereby positioning the bus bar 25 in the Y direction with respect to the holder gripper 53. Note that a guide surface 534 is provided around the positioning recess 535 in the holder gripper 53 to guide the pair of protrusions 255 into the positioning recess 535.

[0055] 6, the width of positioning recess 535 in the X direction narrows toward the Y side. Both side surfaces of paired protrusions 255 abut against the inner surfaces of positioning recess 535, thereby positioning bus bar 25 with respect to holder gripper 53 in the X direction and the Y direction.

[0056] 1 is configured to be able to drive the holder gripper 53 in the Y direction, and is also configured to be able to perform operations of gripping and releasing the first bus bar holder 20a by the holder gripper 53. Note that the operations of gripping and releasing the first bus bar holder 20a may be performed mechanically in conjunction with the driving of the holder gripper 53 in the Y direction, or may be performed separately from the driving in the Y direction.

[0057] 1 performs predetermined positioning control, opening control, attachment control, and release control by controlling comb-tooth drive device 52 and gripper drive device 54. In this way, first bus bar holder 20a is attached to the Y-side end of cell stack 10.

[0058] The terms "positioning control," "opening control," "attachment control," and "release control" may be read as "positioning process," "opening process," "attachment process," and "release process," respectively. In other words, the control device 59 automatically executes the busbar holder attaching method including the positioning process, opening process, attaching process, and release process.

[0059] As mentioned above, the above description is of the holder attachment device 50 when viewed in the first attachment state.

[0060] Next, a procedure for actually attaching the first bus bar holder 20a to the Y-side end of the cell stack 10 using the holder attachment device 50 described above will be described.

[0061] First, as shown in Fig. 1, an operator sets the Y-side end of the cell stack 10 and the first bus bar holder 20a in the holder mounting device 50. Then, the operator operates the holder mounting device 50. This causes the control device 59 of the holder mounting device 50 to execute the positioning control, opening control, mounting control, and release control described above.

[0062] First, in the positioning control, holder gripper 53 is driven by gripper driving device 54, causing holder gripper 53 to grip first bus bar holder 20a on the Y-side relative to the plurality of tab leads N, P on the Y-side. At this time, protrusions 255 of bus bars 25-28 engage with the plurality of positioning recesses 535 shown in FIG. 4, thereby positioning each of bus bars 25-28 in the X direction relative to holder gripper 53 and first bus bar holder 20a.

[0063] On the other hand, in the open control, from the initial state shown in Fig. 9, the comb tooth drive device 52 drives the Z-side comb tooth jig 51b toward the Z+ side and drives the Z+ side comb tooth jig 51b toward the Z- side, as shown in Fig. 10. As a result, the Z-side comb tooth jig 51b is inserted toward the Z+ side between the tab leads P and N that should be electrically connected to each other, and the Z+ side comb tooth jig 51a is inserted toward the Z- side. As a result, the tip ends of the tab leads P and N are opened in the X direction.

[0064] It should be noted that the positioning control and the opening control may be performed one after the other, or may be performed simultaneously.

[0065] In the attachment control that follows the positioning control and the opening control, gripper drive device 54 moves holder gripper 53 and first bus bar holder 20a shown in FIG. 10 from the Y- side of the plurality of tab leads P and N on the Y- side toward the Y+ side as shown in FIG. 11. This movement causes the tips of tab leads P and N, i.e., the ends on the Y- side, to pass through insertion holes 22. Then, when viewed in the X direction, the tips of tab leads P and N overlap bus bars 25-28.

[0066] 12, the Z-side comb-tooth jig 51b is moved to the Z- side, and the Z+ side comb-tooth jigs 51a and 51b are moved to the Z+ side. This causes the comb-tooth jigs 51a and 51b to be removed from between the tab leads P and N. This narrows the gap in the X direction between the tip ends of the tab leads P and N that should be electrically connected to each other.

[0067] Thereafter, holder gripping tool 53 and first bus bar holder 20a are moved further toward the Y+ side as shown in Fig. 13. As a result, first bus bar holder 20a is attached to a plurality of Y- side tab leads N, P in cell stack 10 as shown in Fig. 14.

[0068] In the release control that follows the attachment control, the gripping of first bus bar holder 20a by holder gripping tool 53 is released as shown in Fig. 15, and the positioning of bus bars 25-28 by positioning recesses 535 shown in Fig. 4 is released. As a result, bus bar 25 is arranged between tab leads P and N that are to be electrically connected to each other within the range of elongated hole 253 so as to be movable in the X direction and rotatable about holding pin 23 as an axis, as shown in Fig. 15.

[0069] Next, a procedure for attaching the second bus bar holder 20b shown in FIG. 16 to the cell stack 10 to which the first bus bar holder 20a has been attached will be described.

[0070] The worker removes the cell stack 10 shown in FIG. 15 to which the first bus bar holder 20a has been attached from the holder attachment device 50, and rotates the cell stack 10 by 180° around the Z direction as an axis. The worker sets the Y+ side end of the cell stack 10 and the second bus bar holder 20b in the holder attachment device 50. Then, the holder attachment device 50 is operated.

[0071] As a result, the positioning control, opening control, attachment control, and release control are executed again in substantially the same manner as described above, and as a result, the second bus bar holder 20b is attached to the Y+ side surface of the cell stack 10, as shown in FIG.

[0072] Hereinafter, the cell stack 10 to which the first bus bar holders 20a and the second bus bar holders 20b are attached in this manner will be referred to as the "cell stack 10 with holders attached."

[0073] Next, a clamp device 70 shown in Fig. 17 will be described. The clamp device 70 is configured to be able to clamp each of the bus bars 25 to 28 of the first bus bar holder 20a in the cell stack 10 after the holder has been attached. The clamp device 70 is also configured to be able to clamp each of the bus bars 25 of the second bus bar holder 20b in the cell stack 10 after the holder has been attached.

[0074] Hereinafter, the state in which clamp device 70 clamps busbars 25-28 of first busbar holder 20a will be referred to as the "first clamping state." Additionally, the state in which clamp device 70 clamps busbar 25 of second busbar holder 20b will be referred to as the "second clamping state."

[0075] The clamp device 70 shown in FIG. 17 is configured as follows when viewed in the first clamping state.

[0076] As shown in FIG. 17, the clamp device 70 includes a base member 71 , a moving device 72 , a plurality of working pairs 73 , a plurality of driving devices 74 , and a control device 79 .

[0077] As shown in Fig. 18, the base member 71 extends in the X and Z directions. The moving device 72 shown in Fig. 17 is configured to be able to move the base member 71 in the X and Y directions.

[0078] 17, an action pair 73 is provided for every other one of the multiple bus bars 25 to 28 lined up in the X direction. Each action pair 73 includes a first action portion 73a and a second action portion 73b. The first action portion 73a is attached to the base member 71 and is arranged on the X+ side of the bus bar 25 to be clamped. The second action portion 73b is attached to the base member 71 so as to be movable in the X direction relatively, and is arranged on the X- side of the bus bar 25 to be clamped.

[0079] The pitch in the X direction between the first acting portion 73a and the second acting portion 73b changes from a predetermined pre-clamping pitch xB shown in Fig. 22 to a smaller clamping pitch xC shown in Fig. 24. Due to this change, the acting pair 73 clamps the bus bar 25 together with the adjacent tab leads P and N in the X direction.

[0080] 18, a driving device 74 is provided for each second action portion 73b. The driving devices 74 are attached to the base member 71 and lined up in the X direction. Each driving device 74 moves the second action portion 73b relative to the base member 71 in the X direction.

[0081] Specifically, each drive device 74 includes a pair of air cylinders 741 provided on both sides of the second action part 73b to be driven in the Z direction, and a power conversion mechanism 748 provided for each air cylinder 741. Each air cylinder 741 includes a cylinder body 741a and a rod 741b that protrudes inward in the Z direction from the cylinder body 741a. Each power conversion mechanism 748 converts the force in the Z direction by the rod 741b into a force in the X direction and transmits it to the second action part 73b.

[0082] More specifically, the power conversion mechanism 748 includes, for example, a rod-side member 744 that moves in the Z direction together with the rod 741b, and an action unit-side member 747 that moves in the X direction together with the second action unit 73b. The rod-side member 744 is provided with an elongated hole 745 that extends toward the X+ side as it moves outward in the Z direction. On the other hand, the action unit-side member 747 is provided with an engagement pin 746 that engages with the elongated hole 745. As described above, the power conversion mechanism 748 converts the force acting inward in the Z direction by the pair of rods 741b into a force acting toward the X+ side and transmits it to the second action unit 73b. The power conversion mechanism 748 also converts the force acting outward in the Z direction by the pair of rods 741b into a force acting toward the X- side and transmits it to the second action unit 73b.

[0083] From the above, when the air pressure of the pair of air cylinders 741 is OFF, the second action portion 73b is disposed on the X- side, and the pitch in the X direction between the second action portion 73b and the first action portion 73a becomes the pre-clamp pitch xB shown in Fig. 22. On the other hand, when the air pressure of the pair of air cylinders 741 is ON, the second action portion 73b is disposed on the X+ side, and the pitch in the X direction between the second action portion 73b and the first action portion 73a becomes the clamp pitch xC shown in Fig. 24.

[0084] 18, the center of gravity of the drive device 74 located on the X+ side of the predetermined first position p1 is located on the X+ side of the center of gravity of the second acting portion 73b driven by the drive device 74. The center of gravity of the drive device 74 located closer to the X+ side is more offset to the X+ side from the center of gravity of the second acting portion 73b driven by the drive device 74. On the other hand, the center of gravity of the drive device 74 located on the X- side of the second position p2 located on the X- side of the first position p1 is located on the X- side of the center of gravity of the second acting portion 73b driven by the drive device 74. The center of gravity of the drive device 74 located closer to the X- side is more offset to the X- side from the center of gravity of the second acting portion 73b driven by the drive device 74.

[0085] As shown in FIG. 18 , the clamping device 70 further includes an X+-side pitch change device 80a and an X-side pitch change device 80b. The X+-side pitch change device 80a is configured to be able to change the pre-clamp pitch xB of the working pair 73 at the end of the X+ side. On the other hand, the X-side pitch change device 80b is configured to be able to change the pre-clamp pitch xB of the working pair 73 at the end of the X- side. The X+-side pitch change device 80a includes a first change device 83 and two second change devices 86. On the other hand, the X-side pitch change device 80b includes two second change devices 86.

[0086] The first changing device 83 of the pitch changing device 80a on the X+ side is configured to be able to move the first acting portion 73a at the end on the X+ side in the X direction relative to the base member 71. This allows the pre-clamp pitch xB of the acting pair 73 at the end on the X+ side to be expanded toward the X+ side and contracted toward the X- side.

[0087] The two second change devices 86 of the X+-side pitch change device 80a are configured to be able to change the movable range of the second acting portion 73b at the X+-side end toward the X- side. This allows the pre-clamp pitch xB of the acting pair 73 at the X+-side end to be expanded toward the X- side and contracted toward the X+ side. Furthermore, this X+-side pitch change device 80a is configured to be able to freely change the positions of the first acting portion 73a and the second acting portion 73b in the X direction in this way, and therefore is configured to be able to freely change the clamp position in the X direction.

[0088] The two second change devices 86 of the X-side pitch change device 80b are configured to be able to change the movable range of the second acting portion 73b at the X-side end toward the X-side, thereby enabling the pre-clamp pitch xB of the acting pair 73 at the X-side end to be expanded toward the X-side and contracted toward the X+ side.

[0089] Specifically, each second changing device 86 changes the movable range of the second acting part 73b in the X- direction by changing the movable range of the rod 741b of the air cylinder 741 outward in the Z direction, that is, the movable range when the air pressure is OFF. More specifically, each second changing device 86 includes a stopper 865 with which the rod side member 744 abuts outward in the Z direction, and a stopper moving device 862 that moves the stopper 865 in the Z direction.

[0090] 17 controls the movement device 72, multiple drive devices 74, and two pitch change devices 80a, 80b to clamp each bus bar 25-28 of the first bus bar holder 20a together with the adjacent tab leads P, N. In other words, the control device 59 automatically performs a predetermined bus bar clamping method. Furthermore, the clamp device 70 welds each tab lead P, N at the Y-side end of the cell stack 10 to the adjacent bus bars 25-28.

[0091] As mentioned above, the above description is of the clamp device 70 when viewed in the first clamping state.

[0092] Next, a procedure for actually clamping each of the bus bars 25 to 28 using the clamp device 70 described above and welding each of the tab leads N, P of the cell stack 10 to the adjacent bus bar 25 will be described.

[0093] First, the worker sets the X+ side portion of the Y- side end of the cell stack 10, which has already been attached to the holder as shown in Fig. 16, onto the clamp device 70. Then, the clamp device 70 is operated.

[0094] 18, the control device 79 first changes the pre-clamp pitch xB of the working pairs 73 at both ends in the X direction to a desired pitch. That is, the pre-clamp pitch xB of the working pairs 73 at the end on the X+ side is changed to a pitch that is larger by a predetermined amount than the X-direction width of the bus bar 27 at the end on the plus side. On the other hand, the pre-clamp pitch xB of the working pairs 73 at the end on the X- side is changed to a pitch that is larger by a predetermined amount than the X-direction width of the central bus bar 26.

[0095] Next, as shown in Fig. 19, each odd-numbered bus bar 26, 25, 27 is clamped together with the adjacent tab leads P, N by each working pair 73. Details of this operation will be described later. In this clamped state, each tab lead P, N is welded to the adjacent bus bar 26, 25, 27. Thereafter, the control device 79 releases the working pairs 73 from clamping the odd-numbered bus bars 26, 25, 27.

[0096] Next, the control device 59 uses the X+-side pitch change device 80a shown in Fig. 18 to change the pre-clamp pitch xB of the working pair 73 at the end of the X+ side to a pitch that is a predetermined amount larger than the X-directional width of the normal-width bus bar 25. Note that the working pair 73 at the end of the X- side is not used here, so there is no need to particularly change the pre-clamp pitch xB.

[0097] 20 , each of the even-numbered bus bars 25 is clamped together with the adjacent tab leads P and N by each of the action pairs 73 other than the action pair 73 at the end on the X-side. In this clamped state, each of the tab leads P and N is welded to the adjacent bus bar 25. Thereafter, the control device 79 releases the clamping of each of the even-numbered bus bars 25 by each of the action pairs 73.

[0098] As a result, as shown in FIG. 26, welding W to the adjacent bus bar 25 for each tab lead P, N is completed at the X+ side portion of the Y- side end of the cell stack 10 that has already been attached to the holder.

[0099] Next, the worker places the X-side portion of the Y-side end of the cell stack 10 that has already been attached to the holder onto the clamp device 70. Then, the clamp device 70 is operated. As a result, in substantially the same manner as above, each tab lead P, N is welded to the adjacent bus bar 25 at the X-side portion of the Y-side end.

[0100] Next, the worker places the X- side portion of the Y+ side end of the cell stack 10 that has already been attached to the holder onto the clamp device 70. Then, the clamp device 70 is operated. As a result, in substantially the same manner as above, each tab lead P, N is welded to the adjacent bus bar 25 at the X- side portion of the Y+ side end.

[0101] Next, the worker places the X+ side portion of the Y+ side end of the cell stack 10 that has already been attached to the holder onto the clamp device 70. Then, the clamp device 70 is operated. As a result, in substantially the same manner as above, each tab lead P, N is welded to the adjacent bus bar 25 at the X+ side portion of the Y+ side end.

[0102] By the above, as shown in FIG. 27, welding W to adjacent bus bars 25 to 28 for each of tab leads N, P of the entire cell stack 10 is completed.

[0103] Next, the operation of each working pair 73 during the collective clamping and welding described above will be described in detail.

[0104] First, as shown in Fig. 21, the control device 59 moves the base member 71 from a state in which the acting pair 73 is disposed on the Y- side of the bus bar 25 to be clamped to the Y+ side as shown in Fig. 22. As a result, the acting pair 73 is disposed in a position overlapping the bus bar 25 to be clamped when viewed in the X direction. In other words, the second acting portion 73b is disposed on the X- side of the bus bar 25 to be clamped, and the first acting portion 73a is disposed on the X+ side of the bus bar 25 to be clamped. Note that the pitch in the X direction between the second acting portion 73b and the first acting portion 73a at this time is the pre-clamping pitch xB described above.

[0105] From this state, as shown in Fig. 23, the base member 71 is moved toward the X-side by the moving device 72. As a result, the second acting portion 73b and the first acting portion 73a move toward the X-side while maintaining the pre-clamping pitch xB. As a result, the second acting portion 73b moves away from the bus bar 25 to be clamped, while the first acting portion 73a moves closer to the bus bar 25 to be clamped. At this time, the first acting portion 73a may or may not come into contact with the bus bar 25 to be clamped.

[0106] 24, the second acting portion 73b is moved toward the X+ side relative to the base member 71 by the driving device 74. This causes the acting pair 73 to clamp the bus bar 25 together with the adjacent tab leads P and N. At this time, the pitch in the X direction between the second acting portion 73b and the first acting portion 73a is the clamp pitch xC described above.

[0107] 25, a laser beam Lb is applied between the bus bar 25 and the tab leads P, N to perform welding W. As a result, the tab leads P, N on both sides of the bus bar 25 are joined to the bus bar 25.

[0108] The above-mentioned operation or an operation substantially similar to the above is performed simultaneously by each of the working pairs 73, whereby the above-mentioned collective clamping and welding is performed.

[0109] The configuration and effects of the bus bar holders 20a and 20b shown in FIG. 16 will be summarized below.

[0110] As shown in Fig. 3, in the mounted state, bus bars 25, 26 are held between the insertion holes 22 of the first bus bar holder 20a so as to be movable in the X direction relative to the first bus bar holder 20a. Therefore, as shown in Fig. 14, by inserting the tab leads P, N into the insertion holes 22 and mounting the bus bar holder 20a to the Y direction end of the cell stack 10, the bus bars 25, 26 are arranged between the tab leads P, N so as to be movable in the X direction, as shown in Fig. 15.

[0111] From this state, as shown in FIG. 24 , by clamping the busbars 25 and 26 together with the tab leads P and N on both sides thereof with the operating pair 73, the busbar 25 moves to an appropriate position in the X direction between the tab leads P and N within the range of the elongated hole 253. In other words, even if the relative position of each battery cell 15 in the X direction with respect to the busbar holder 20a deviates from the desired position due to expansion of the battery cell 15 or the like, the busbar 25 can be moved to an appropriate position in the X direction within the range of the elongated hole 253. The appropriate position is, for example, a position where the clamping force from both sides in the X direction is equal. Furthermore, the tab leads P and N adjacent to the busbar 25 on both sides bend in accordance with the movement of the busbar 25. As described above, according to this embodiment, the busbar 25 can be easily clamped without any strain.

[0112] 3, when viewed in an attached state, bus bar 25 has elongated holes 253 formed therein that extend in the X direction. Retaining pin 23 is inserted through elongated hole 253 in the Y direction, thereby holding bus bar 25 relative to bus bar holder 20a so that bus bar 25 can be moved in the X direction relative to bus bar holder 20a. Therefore, with this simple configuration of retaining pin 23 and elongated hole 253, bus bar 25 can be held relative to bus bar holder 20a so that it can be moved in the X direction relative to bus bar holder 20a.

[0113] 3, when viewed in the mounted state, the elongated hole 253 is provided in the middle of the bus bar 25 extending in the Z direction. As a result, the bus bar 25 is held by the bus bar holder 20a so as to be rotatable about the retaining pin 23. This makes it possible to accommodate misalignment of the bus bar 25 in the rotation direction relative to the tab leads P and N.

[0114] 27, it is preferable that the bus bars 25-28 do not move relative to the cell stack 10 and the bus bar holders 20a, 20b in the state of the battery module 30. In this regard, according to this embodiment, the bus bars 25-28 can be positioned in the X direction relative to the cell stack 10 and the bus bar holders 20a, 20b simply by attaching the bus bar holders 20a, 20b to the cell stack 10 and welding the tab leads P, N to the adjacent bus bars 25-28.

[0115] The configuration and effects of the holder mounting device 50 shown in FIG. 1 will be summarized below.

[0116] As shown in Fig. 4, in the positioning control, multiple bus bars 25-28 are positioned in the X direction relative to the holder gripping tool 53 and the bus bar holder 20a. Also, as shown in Fig. 10, in the opening control, comb-tooth jigs 51a and 51b are inserted between the tab leads P and N to be electrically connected, thereby opening the tips of the tab leads P and N in the X direction. As a result, in the subsequent installation control shown in Fig. 11, when the holder gripping tool 53 and the bus bar holder 20a are moved toward the cell stack 10 to arrange the bus bar 25 between the tab leads P and N, interference between the bus bar 25 and the tab leads P and N can be suppressed. This ensures efficient installation of the bus bar holders 20a and 20b to the cell stack 10.

[0117] Moreover, in the release control that follows the attachment control, the positioning of bus bar 25 in the X direction by holder gripping tool 53 shown in Fig. 4 is released. Therefore, if bus bar 25 is subsequently clamped together with adjacent tab leads P and N as shown in Fig. 24, bus bar 25 moves to an appropriate position in the X direction within the range of elongated hole 253, as described above. This makes it easy to clamp bus bars 25 to 28 without any strain.

[0118] As described above, according to this embodiment, it is possible to ensure the efficiency of the work when attaching the bus bar holders 20a, 20b to the cell stack 10, while also making it easy to clamp the bus bars 25 to 28 without strain.

[0119] In the attachment control shown in FIG. 11, the holder gripping tool 53 and the bus bar holder 20a are moved so that the bus bar 25 overlaps the tips of the tab leads P and N when viewed in the X direction. Then, as shown in FIG. 12, the comb-tooth jigs 51a and 51b are removed from between the tab leads P and N. Then, as shown in FIG. 13, the holder gripping tool 53 and the bus bar holder 20a are further moved toward the cell stack 10. This allows the comb-tooth jigs 51a and 51b to be removed at an appropriate timing. This further improves the efficiency of attaching the bus bar holders 20a and 20b to the cell stack 10.

[0120] 5, bus bars 25 to 28 have a pair of protrusions 255 that protrude in the Y direction. Holder gripper 53 is formed with positioning recesses 535 that engage with the pair of protrusions 255. Therefore, with this simple configuration of the pair of protrusions 255 and the positioning recesses 535, bus bar 25 can be positioned in the X direction relative to holder gripper 53.

[0121] 5, the side surfaces of the pair of protrusions 255 abut against the inner surfaces of the positioning recess 535, thereby positioning the bus bar 25 in the X direction relative to the holder gripper 53. Furthermore, the tips of the pair of protrusions 255 abut against the bottom surfaces of the positioning recess 535, thereby positioning the bus bar 25 in the Y direction relative to the holder gripper 53. Therefore, the bus bar 25 can be positioned in both the X direction and the Y direction relative to the holder gripper 53.

[0122] 6, the width of positioning recess 535 in the X direction narrows toward the Y-side. The side surfaces of protrusions 255 come into contact with the inner surfaces of positioning recess 535, thereby positioning bus bar 25 in the X and Y directions relative to holder gripper 53. Therefore, this embodiment also allows bus bar 25 to be positioned in both the X and Y directions relative to holder gripper 53.

[0123] The configuration and effects of the clamp device 70 shown in FIG. 17 will be summarized below.

[0124] The control device 79 causes the drive device 74 to move the second action portion 73b toward the X+ side as shown in FIG. 24. The second action portion and the first action portion 73a clamp the bus bar 25 in the X direction. Therefore, as shown in FIG. 17, it is sufficient to provide the drive device 74 only for the second action portion 73b out of the second action portion 73b and the first action portion 73a. This allows for a simpler drive system for the action pair 73 than when the drive device 74 is required for both the second action portion 73b and the first action portion 73a.

[0125] Furthermore, the control device 79 moves the base member 71 to the X- side to move the first acting portion 73a to the X- side as shown in Fig. 23, and then moves the second acting portion 73b to the X+ side as shown in Fig. 24. This causes the second acting portion 73b and the first acting portion 73a to clamp the bus bar 25 in the X direction. In this way, by moving the first acting portion 73a in the X direction as the base member 71 moves, the functionality of the operation of clamping the bus bar 25 can be ensured.

[0126] As described above, according to this embodiment, the drive system for the working pair 73 can be configured simply while ensuring the functionality of the work of clamping the bus bars 25 to 28.

[0127] 19, the control device 79 shown in Fig. 17 performs batch clamping in which a plurality of bus bars 25 are clamped together by a plurality of action pairs 73. By this batch clamping, the plurality of bus bars 25 can be clamped efficiently.

[0128] As shown in Fig. 19, the control device 79 performs collective clamping on the odd-numbered bus bars 25, and then performs collective clamping on the even-numbered bus bars 25, as shown in Fig. 20. Therefore, as shown in Fig. 17, it is sufficient to provide an operating pair 73 for every other one of the multiple bus bars 25 to 28 lined up in the X direction. This makes it easier to ensure installation space for the operating pairs 73 and their driving devices 74.

[0129] 18, the drive units 74 are arranged side by side in the X direction. Each drive unit 74 includes an air cylinder 741 that applies force in the Z direction, and a power conversion mechanism 748 that converts the force of the air cylinder 741 in the Z direction into a force in the X direction and transmits it to the second action unit 73b. As such, because each drive unit 74 includes the air cylinder 741 that applies force in the Z direction, it tends to be long in the Z direction, but tends to be compact in the X direction. Therefore, in this respect, it is easy to ensure installation space in the X direction for the drive units 74 that are arranged side by side in the X direction.

[0130] 18, regarding the X+ side of the predetermined first position p1, the more the center of gravity of the drive unit 74 is on the X+ side, the greater the deviation toward the X+ side from the center of gravity of the second acting portion 73b driven by that drive unit 74. On the other hand, regarding the X- side of the second position p2, the more the center of gravity of the drive unit 74 is on the X- side, the greater the deviation toward the X- side from the center of gravity of the second acting portion 73b driven by that drive unit 74. Therefore, even when the acting pairs 73 are closely arranged in the X direction, it is easy to arrange the drive units 74 by spreading them out in the X direction. Therefore, in this respect, it is easy to secure installation space in the X direction for the drive units 74 arranged in the X direction.

[0131] The configuration and effects of the pitch changers 80a and 80b shown in FIG. 18 will be summarized below.

[0132] 18 change the pre-clamp pitch xB of the working pair 73 at the end in the X direction. Therefore, if the busbars clamped by the working pair 73 at the end in the X direction are the special-width busbars 26-28, the pitch change devices 80a and 80b can change the pre-clamp pitch xB of the working pair 73 to match the special-width busbars 26-28. Also, if the busbar clamped by the working pair 73 at the end in the X direction is the normal-width busbar 25, the pitch change devices 80a and 80b can change the pre-clamp pitch xB of the working pair 73 to match the normal-width busbar 25. Therefore, this can accommodate both the special-width busbars 26-28 and the normal-width busbar 25.

[0133] The control device 79 shown in Fig. 17 clamps odd-numbered bus bars 25 using multiple acting pairs 73 as shown in Fig. 19. Then, pitch change devices 80a and 80b shown in Fig. 18 change the pre-clamp pitch xB of the acting pairs 73 at the ends in the X direction. Then, as shown in Fig. 20, even-numbered bus bars 25 are clamped using multiple acting pairs 73. Therefore, this embodiment can also accommodate cases where the odd-numbered bus bars at the ends in the X direction are special-width bus bars 26 and 28 and the even-numbered bus bars at the ends in the X direction are normal-width bus bars 25.

[0134] Specifically, in this embodiment, as shown in Fig. 16, a plurality of battery cells 15 are stored between end plates 121, 123 and a center plate 122. The bus bars 27, 28 adjacent to the end plates 121, 123 and the bus bar 26 adjacent to the center plate 122 are special width bus bars 26-28. Therefore, the special width bus bars 26-28 can also be accommodated.

[0135] 18 is capable of increasing the pre-clamping pitch xB toward the X+ side and decreasing it toward the X- side by changing the arrangement of the first acting portion 73a relative to the base member 71 in the X direction. Therefore, with such a simple configuration, the pre-clamping pitch xB can be increased toward the X+ side and decreased toward the X- side.

[0136] 18 is capable of increasing the pre-clamping pitch xB toward the X- side and decreasing it toward the X+ side by changing the movable range of the second acting portion 73b toward the X- side relative to the base member 71. Therefore, with such a simple configuration, the pre-clamping pitch xB can be increased toward the X- side and decreased toward the X+ side.

[0137] More specifically, the second changing device 86 changes the outward movable range of the rod 741b of the air cylinder 741 in the Z direction. This changes the movable range of the second acting portion 73b toward the X- side relative to the base member 71. This makes it possible to increase the pre-clamping pitch xB toward the X- side and decrease it toward the X+ side. Therefore, with such a simple configuration, the pre-clamping pitch xB can be increased toward the X- side and decreased toward the X+ side.

[0138] [Other embodiments] The above-described embodiment can be modified, for example, as follows. The holder mounting device 50 shown in FIG. 1 does not need to be equipped with the control device 59. The controls that should be performed by the control device 59 may be performed manually by an operator as each process. The clamping device 70 shown in FIG. 17 does not need to be equipped with the control device 79. The controls that should be performed by the control device 79 may be performed manually by an operator as each process.

[0139] The pitch change devices 80a and 80b may be provided for other acting pairs 73 instead of or in addition to the acting pair 73 at the end in the X direction. By such a change, the pitch of any acting pair 73 can be changed. [Explanation of symbols]

[0140] 10 Cell stack 15 battery cells 20a First bus bar holder 20b Second bus bar holder 22 Inserted part 23 Retaining pin 25 Normal width busbar 253 long hole 255 Protrusion 26 Center bus bar 53 Holder gripper 535 Positioning recess N Negative electrode tab lead P Positive electrode tab lead

Claims

1. A bus bar holder attached to a cell stack including a plurality of battery cells arranged in a predetermined X direction, the battery cells including tab leads protruding in a Y direction perpendicular to the X direction, When the bus bar holder is attached to the cell stack, as viewed in an attachment state, a plurality of insertion portions into which the tab leads can be inserted in the Y direction are formed and aligned in the X direction; a bus bar for electrically connecting the tab leads to each other is held between the insertion portions so as to be movable in the X direction relative to the bus bar holder; The bus bar has a long hole formed therein, the long hole extending in the X direction. a predetermined holding pin provided on the bus bar holder is inserted through the elongated hole in the Y direction, thereby holding the bus bar so as to be movable relative to the bus bar holder in the X direction; Busbar holder.

2. In the above mounting state, the bus bar extends in a Z direction perpendicular to the X direction and the Y direction, the elongated hole is provided in a middle portion of the bus bar in the Z direction, and the bus bar is held by the bus bar holder so as to be rotatable about the holding pin. The bus bar holder according to claim 1 .

3. In the above mounting state, The bus bar is provided with a protruding portion that protrudes in the Y direction, a positioning recess formed in a holder gripping tool that grips the bus bar holder engages with the protrusion, thereby positioning the bus bar in the X direction with respect to the holder gripping tool and the bus bar holder. The bus bar holder according to claim 1 or 2.

4. A bus bar holder attached to a cell stack including a plurality of battery cells arranged in a predetermined X direction, the battery cells including tab leads protruding in a Y direction perpendicular to the X direction, When the bus bar holder is attached to the cell stack, as viewed in an attachment state, a plurality of insertion portions into which the tab leads can be inserted in the Y direction are formed and aligned in the X direction; a bus bar for electrically connecting the tab leads to each other is held between the insertion portions so as to be movable in the X direction relative to the bus bar holder; The bus bar is provided with a protruding portion that protrudes in the Y direction, a positioning recess formed in a holder gripping tool that grips the bus bar holder engages with the protrusion, thereby positioning the bus bar in the X direction with respect to the holder gripping tool and the bus bar holder. Busbar holder.

5. A battery module comprising the bus bar holder according to any one of claims 1, 2 and 4 and the cell stack, the bus bar holder is attached to the cell stack, and the tab lead is joined to the adjacent bus bar, thereby positioning the bus bar in the X direction with respect to the cell stack and the bus bar holder. Battery module.

Images