JP6209972B2 - Dimension adjustment device - Google Patents

Description

  The present invention relates to a size adjusting device for adjusting the size of an electrode assembly in which a plurality of electrodes are layered.

  Conventionally, a lithium ion secondary battery, a nickel hydride secondary battery, or the like is mounted on a vehicle as a power storage device that stores electric power supplied to an electric motor or the like. 2. Description of the Related Art Generally, a secondary battery includes a positive electrode having an active material layer and an electrode assembly in which negative electrodes are stacked in layers, and a case for housing the electrode assembly. In such a secondary battery manufacturing process, the positive electrode and the negative electrode are overlapped to form the electrode assembly 12, and then a predetermined load is applied to the electrode assembly in the overlapping direction of the electrodes. It is performed to adjust the dimensions to a predetermined dimension.

  As an apparatus for applying a load to a predetermined member, for example, an apparatus described in Patent Document 1 has been proposed. In Patent Document 1, the load applied from the pressurization shank is distributed and applied evenly to the two pressurization-side seal blades, thereby suppressing the thermal welding of the casing from becoming uneven.

JP 2002-298799 A

  However, in the electrode assembly described above, since the thickness of the active material layer of each electrode is not strictly constant, even if a load is evenly applied to each part of the electrode assembly, It is difficult to adjust the size of each part of the electrode assembly equally to a predetermined size.

  This invention was made paying attention to the problem which exists in the said prior art, The objective is to provide the dimension adjustment apparatus which can adjust the dimension of the electrode assembly with which the electrode overlapped in layers easily. is there.

An electrode assembly size adjusting device that solves the above-described problem is a size adjusting device that adjusts the size of an electrode assembly in which a plurality of electrodes overlap each other in layers. A pressing member arranged to extend across the first end and the second end located at both ends in a predetermined direction orthogonal to the overlapping direction; and the first region on the first end side in the pressing member In contrast, the first applying mechanism for applying a load along the overlapping direction and the second region on the second end side of the pressing member for applying a load along the overlapping direction. 2 providing mechanism, a first changing mechanism for changing the load applied to the first region, and a second changing mechanism for changing the load applied to the second region , wherein the first applying mechanism comprises: A first lock having a first contact portion in contact with the first region. And a first spring that applies a load to the first rod along the overlapping direction, and the second applying mechanism includes a second contact portion that contacts the second region. It has a gist of having two rods and a second spring that applies a load along the overlapping direction to the second rod .

  According to this configuration, the applied load can be changed separately in the first region and the second region of the pressing member. For this reason, due to the thickness variation of the active material layer or the like, the total thickness of the electrodes stacked in layers differs between the first edge side and the second edge side of the electrode assembly. In addition, the dimension of the electrode assembly in the electrode overlapping direction can be adjusted to a predetermined dimension. Therefore, the dimensions of the electrode assembly in which the electrodes are stacked in layers can be easily adjusted.

  According to this configuration, a load can be applied to the first region and the second region of the pressing member with a simple configuration using a rod and a spring. Therefore, the dimensions of the electrode assembly can be easily adjusted.

  In the electrode assembly size adjusting apparatus, the first changing mechanism is configured to be able to change a load applied to the first region by changing a compression amount of the first spring. It is preferable that the changing mechanism is configured to be able to change the load applied to the second region by changing the compression amount of the second spring.

  According to this configuration, the load applied to the first region and the second region can be changed individually by a simple configuration that changes the compression amount of the spring. Therefore, the dimensions of the electrode assembly can be adjusted more easily.

  According to the present invention, the dimensions of the electrode assembly in which the electrodes are stacked in layers can be easily adjusted.

The perspective view which shows typically the secondary battery disassembled partially. The perspective view which shows typically the decomposed | disassembled electrode assembly. (A) is a top view which shows a dimension adjustment apparatus typically, (b) is the 1-1 sectional view taken on the line of (a).

Hereinafter, an embodiment of a dimension adjusting device used in the manufacturing process of the secondary battery will be described. First, the secondary battery 10 will be described.
As shown in FIG. 1, a secondary battery 10 as a power storage device has a rectangular parallelepiped case 11 made of metal. The case 11 is made of, for example, aluminum or aluminum alloy. The case 11 includes a bottomed square cylindrical case main body 11a and a lid 11b that closes an opening of the case main body 11a. An electrode assembly 12 is accommodated in the case 11. The case 11 is filled with an electrolyte (electrolytic solution) (not shown). The secondary battery 10 of this embodiment is a lithium ion secondary battery.

  As shown in FIG. 2, the electrode assembly 12 is a stacked electrode assembly in which a plurality of positive electrodes 13 and a plurality of negative electrodes 14 are alternately overlapped with separators 15 interposed therebetween. . The positive electrode 13, the negative electrode 14, and the separator 15 have a rectangular sheet shape. The positive electrode 13 and the negative electrode 14 are insulated from each other by the separator 15. In the following description, the overlapping direction of the electrodes 13 and 14 in the electrode assembly 12 is simply referred to as “stacking direction DS”.

  The positive electrode 13 is a substantially rectangular metal foil 13a for a positive electrode, a positive electrode active material layer 13b formed on both surfaces thereof, and a current collecting tab protruding from one edge (one side) of the metal foil 13a. Positive electrode tab 13c. The metal foil 13a is, for example, an aluminum foil. The negative electrode 14 includes a metal foil 14a having a substantially rectangular shape, an active material layer 14b for the negative electrode formed on both surfaces thereof, and a current collecting tab protruding from one edge (one side) of the metal foil 14a. A negative electrode tab 14c. The metal foil 14a is, for example, a copper foil.

  As shown in FIG. 1, the electrode assembly 12 has a substantially rectangular parallelepiped shape as a whole. The electrode assembly 12 has an end face 12a and an end face 12b at both ends in the stacking direction DS. The electrode assembly 12 has an end face 12c and an end face 12d at both ends in a first direction D1 orthogonal to the stacking direction DS. The electrode assembly 12 has an end face 12e as a first end and an end face 12f as a second end at both ends of a second direction D2 as a predetermined direction orthogonal to the stacking direction DS and the first direction D1. The end faces 12 a to 12 f of this embodiment are all part of the edge (end) of the electrode assembly 12.

  The electrode assembly 12 has a positive electrode tab group 13d as a current collecting tab group in which a plurality of positive electrode tabs 13c are stacked in layers by stacking a plurality of positive electrode electrodes 13. The positive electrode tab group 13 d protrudes from the end surface 12 c of the electrode assembly 12. The electrode assembly 12 includes a negative electrode tab group 14d as a current collecting tab group in which a plurality of negative electrode tabs 14c are stacked in layers by stacking a plurality of negative electrode electrodes 14. The negative electrode tab group 14 d protrudes from the end surface 12 c of the electrode assembly 12.

  The electrode assembly 12 includes a plurality of (four in this embodiment) holding tapes 16 that hold the positive electrode 13, the negative electrode 14, and the separator 15 in a mutually positioned state. Each holding tape 16 has a strip shape. Both ends of each holding tape 16 in the longitudinal direction are fixed to end faces 12a and 12b of the electrode assembly 12, respectively. Each holding tape 16 covers a part of the end faces 12c and 12d.

  The secondary battery 10 has a positive electrode terminal 17 fixed to the lid 11 b so as to protrude outside the case 11, and a negative electrode terminal 18 fixed to the lid 11 b so as to protrude outside the case 11. The secondary battery 10 includes a conductive member 21 that electrically connects the positive electrode tab group 13 d and the positive electrode terminal 17. The positive electrode tab group 13d is welded to the conductive member 21 in a state where the positive electrode tabs 13c constituting the positive electrode tab group 13d are gathered in the stacking direction DS.

  Further, the secondary battery 10 includes a conductive member 22 that electrically connects the negative electrode tab group 14 d and the negative electrode terminal 18. The negative electrode tab group 14d is welded to the conductive member 22 in a state where the negative electrode tabs 14c constituting the negative electrode tab group 14d are gathered together in the stacking direction DS.

  Next, the dimension adjusting device 30 of the electrode assembly 12 will be described. The size adjusting device 30 is a device for adjusting the size of the electrode assembly 12 along the stacking direction DS (hereinafter referred to as “thickness” for convenience of description) to a predetermined size.

  As shown in FIG. 3A and FIG. 3B, the dimension adjusting device 30 is disposed so as to be in surface contact with the end surface 12a of the electrode assembly 12, and is end surfaces positioned at both ends in the second direction D2. 12e and a rectangular plate-like pressing member 31 arranged to extend across the end face 12f. That is, the pressing member 31 is disposed so as to extend along the end surface 12c from which the positive electrode tab group 13d and the negative electrode tab group 14d protrude. The pressing member 31 has a contact surface that comes into contact with the end surface 12 a of the electrode assembly 12.

  The pressing member 31 has a first recess 33a as a first region and a second recess 33b as a second region on the surface opposite to the contact surface. The first recess 33 a is provided on the end surface 12 e side in the pressing member 31, while the second recess 33 b is provided on the end surface 12 f side in the pressing member 31.

  The dimension adjusting device 30 is disposed so as to be in surface contact with the end surface 12b of the electrode assembly 12, and is disposed so as to extend across the end surface 12e and the end surface 12f located at both ends in the second direction D2. The support member 32 has a rectangular plate shape. That is, the support member 32 is disposed so as to extend along the end surface 12 c of the electrode assembly 12. The support member 32 has a contact surface that contacts the end surface 12 b of the electrode assembly 12. The pressing member 31 and the support member 32 are made of metal such as aluminum or aluminum alloy, for example.

  Further, the dimension adjusting device 30 includes a load mechanism portion 34 for applying a load to the pressing member 31. The load mechanism 34 has a substantially rectangular plate-like main body 35 extending along the second direction D2 and a lever 36 protruding from the main body 35 along the second direction D2. The main body 35 applies a load along the stacking direction DS to the first recess 33a, and a second applying mechanism applies a load along the stacking direction DS to the second recess 33b. And an applying mechanism 40b.

  The first applying mechanism 40 a includes a first rod 41 a that is supported so as to be movable along the stacking direction DS with respect to the main body portion 35. A substantially spherical first contact portion 42a is fixed to the distal end of the first rod 41a, while a disk-shaped first rod-side support plate 44a is fixed to the proximal end of the first rod 41a. .

  The first application mechanism 40a is supported by the first rod-side support plate 44a, and has a first spring 43a that urges the first rod 41a in the direction toward the electrode assembly 12 in the stacking direction DS. .

  The main body 35 has a first storage chamber 35 a and a second storage chamber 35 b in which the opening of the substantially cylindrical hole is covered with a lid 37. The first spring 43a and the first rod side support plate 44a are accommodated in the first accommodation chamber 35a.

  In the first storage chamber 35a, a disc-shaped first lid-side support plate 45a is disposed on the lid 37 side of the first spring 43a. That is, the first spring 43a is disposed between the first rod side support plate 44a and the first lid side support plate 45a. In the first lid-side support plate 45a, a plurality of inclined walls 48a having inclined portions at the tips are arranged on the same circle on the surface on the lid 37 side.

  A portion of the lid 37 that covers the first storage chamber 35a is provided with a first rotating portion 46a that is supported so as to be rotatable about an axis set along the stacking direction DS. In the first rotating portion 46a, a plurality of inclined walls 49a having inclined portions that are inclined in parallel with the inclined portion of the inclined wall 48a are arranged on the same circle on the surface on the first lid side support plate 45a side. .

  In the present embodiment, by rotating the first rotating portion 46a around the axis, the locking position between the inclined wall 48a and the inclined wall 49a changes, and the support plates 44a and 45a are separated from or close to each other. That is, in the present embodiment, the first lid side support plate 45a is moved along the stacking direction DS so that the compression amount (compression ratio) of the first spring 43a can be arbitrarily changed. The first lid side support plate 45a and the first rotating portion 46a constitute a first changing mechanism 47a that changes the load applied to the first recess 33a.

  The second applying mechanism 40b includes a second rod 41b that is supported so as to be movable along the stacking direction DS with respect to the main body portion 35. A substantially spherical second contact portion 42b is fixed to the distal end of the second rod 41b, while a disc-shaped second rod side support plate 44b is fixed to the proximal end of the second rod 41b. .

  The second application mechanism 40b includes a second spring 43b that is supported by the second rod-side support plate 44b and urges the second rod 41b in the direction of the electrode assembly 12 in the stacking direction DS. . The second spring 43b and the second rod side support plate 44b are accommodated in the second accommodation chamber 35b.

  In the second storage chamber 35b, a disc-shaped second lid-side support plate 45b is disposed on the lid 37 side of the second spring 43b. That is, the second spring 43b is disposed between the second rod side support plate 44b and the second lid side support plate 45b. In the second lid-side support plate 45b, a plurality of inclined walls 48b having inclined portions at the tips are arranged on the same circle on the surface on the lid 37 side.

  A portion of the lid 37 that covers the second storage chamber 35b is provided with a second rotating portion 46b that is rotatably supported around an axis set along the stacking direction DS. In the second rotating portion 46b, a plurality of inclined walls 49b having inclined portions inclined in parallel with the inclined portion of the inclined wall 48b are arranged on the same circle on the surface on the second lid side support plate 45b side. .

  In the present embodiment, by rotating the second rotating portion 46b about the axis, the locking position between the inclined wall 48b and the inclined wall 49b changes, and the support plates 44b and 45b are separated from or close to each other. That is, in the present embodiment, the second lid side support plate 45b is moved along the stacking direction DS so that the compression amount (compression ratio) of the second spring 43b can be arbitrarily changed. The second lid side support plate 45b and the second rotating portion 46b constitute a second changing mechanism 47b that changes the load applied to the second recess 33b.

  Further, the dimension adjusting device 30 holds the support member 32, the electrode assembly 12, the pressing member 31, and the load mechanism portion 34 so that they do not move with respect to each other in the directions DS, D1, and D2. The first holding member 50 and the second holding member 51 are provided. The holding members 50 and 51 are disposed at both ends of the electrode assembly 12 in the second direction D2.

  The first holding member 50 has a substantially rectangular plate shape extending along the stacking direction DS. The first holding member 50 includes a first locking portion 50 a that is locked to the support member 32 and a second locking portion 50 b that is locked to the lid 37 of the load mechanism portion 34. The 1st latching | locking part 50a is provided in the edge part by the side of the support member 32 among the both ends of the 1st holding member 50 in the lamination direction DS. The 2nd latching | locking part 50b is provided in the edge part by the side of the lid | cover 37 among the both ends of the 1st holding member 50 in the lamination direction DS.

  The second holding member 51 has a substantially rectangular plate shape extending along the stacking direction DS. The second holding member 51 includes a first locking portion 51 a that is locked to the support member 32, and a second locking portion 51 b that is locked to the lever 36 in the load mechanism portion 34. The 1st latching | locking part 51a is provided in the edge part by the side of the support member 32 among the both ends of the 2nd holding member 51 in the lamination direction DS. The 2nd latching | locking part 51b is provided in the edge part by the side of the lever 36 among the both ends of the 2nd holding member 51 in the lamination direction DS.

Next, the manufacturing method of the secondary battery 10 using the dimension adjusting device 30 will be described together with the operation.
First, as shown in FIG. 3, the positive electrode 13 and the negative electrode 14 are alternately laminated with a separator 15 interposed therebetween to form an electrode assembly 12. Next, while the pressing member 31 is brought into contact with the end surface 12a of the electrode assembly 12, the support member 32 is brought into contact with the end surface 12b of the electrode assembly 12, and the electrode assembly 12, the pressing member 31, and the supporting member 32 are overlapped. Match. At this time, the pressing member 31 and the support member 32 are disposed so as to extend over the end surfaces 12 e and 12 f of the electrode assembly 12 and along the end surface 12 c of the electrode assembly 12.

  Next, the load mechanism 34 is placed on the pressing member 31. At this time, the first contact portion 42a of the first rod 41a is fitted into the first recess 33a, and the second contact portion 42b of the second rod 41b is fitted into the second recess 33b. Thereby, the load mechanism 34 can be easily positioned with respect to the pressing member 31.

  Next, by locking the first holding member 50 and the second holding member 51, the support member 32, the electrode assembly 12, the pressing member 31, and the load mechanism 34 are moved along the directions DS, D1, and D2. Hold them so that they do not move with each other.

  Next, by rotating the first rotating portion 46a around the axis line, the support plates 44a and 45a are separated or brought close to each other, and the urging force by the first spring 43a, that is, the pressing member 31 via the first rod 41a. The amount of compression of the first spring 43a is adjusted so that the load applied to the first recess 33a becomes a predetermined load.

  Similarly, by rotating the second rotating portion 46b around the axis line, the support plates 44b and 45b are separated or brought close to each other, and the urging force of the second spring 43b, that is, the pressing member 31 is interposed via the second rod 41b. The amount of compression of the second spring 43b is adjusted so that the load applied to the second recess 33b becomes a predetermined load.

  In general, the thicknesses of the active material layers of the positive electrode 13 and the negative electrode 14 vary due to fluctuations in the application amount of the active material mixture containing the active material. For this reason, the thickness of the electrode assembly 12 is not necessarily uniform, and it is difficult to make the thickness of the electrode assembly 12 uniform even when a load is evenly applied to the entire electrode assembly 12. It is.

  In contrast, in the dimension adjusting device 30 of the present embodiment, the load applied to the pressing member 31 can be changed by the first applying mechanism 40a and the second applying mechanism 40b. For this reason, the load applied by the first applying mechanism 40a and the second applying mechanism 40b can be set so that the thickness of the electrode assembly 12 is uniform and specified.

  Next, as shown in FIG. 1, the positive electrode 13, the negative electrode 14, and the separator 15 are held in a mutually positioned state by affixing the holding tape 16. Next, the plurality of positive electrode tabs 13c constituting the positive electrode tab group 13d are welded together with the conductive member 21. Similarly, the plurality of negative electrode tabs 14 c constituting the negative electrode tab group 14 d are welded together with the conductive member 22.

  At this time, in the present embodiment, the electrode assembly 12 is held by the holding tape 16 in a state where the electrode assembly 12 is adjusted to a uniform thickness, and therefore the thicknesses of the positive electrode tab group 13d and the negative electrode tab group 14d are also substantially the same. Has been adjusted. Therefore, welding between the tab groups 13d and 14d and the conductive members 21 and 22 can be easily performed.

  For example, in the configuration in which a load is uniformly applied to the entire electrode assembly 12, the thickness of the electrode assembly 12 cannot necessarily be uniform, and thus the thickness of one current collecting tab group becomes larger than specified. There is a possibility that. In such a case, when collecting the current collecting tabs, the tension at the proximal end portion of the current collecting tab farthest from the conductive member becomes high, and welding between the current collecting tab group and the conductive member may be difficult. There is sex. In this embodiment, such a problem can be suitably solved.

  Next, the conductive member 21 and the positive electrode terminal 17 are connected. Further, the conductive member 22 and the negative electrode terminal 18 are connected. Next, the electrode assembly 12 is accommodated in the case main body 11a with the terminals 17 and 18 protruding from the case 11, and the opening of the case main body 11a is sealed with the lid 11b. Thereafter, the secondary battery 10 is completed by charging the case 11 with an electrolyte.

According to the above embodiment, the following effects can be obtained.
(1) The load to be applied can be changed for each of the first recess 33 a and the second recess 33 b of the pressing member 31. For this reason, even if the total thickness of the overlapped electrodes is different between the end face 12e side and the end face 12f side of the electrode assembly 12 due to the thickness variation of the active material layer or the like, the electrode The thickness of the assembly 12 can be adjusted to a predetermined dimension. Therefore, the dimensions of the electrode assembly 12 in which the electrodes are stacked in layers can be easily adjusted.

  (2) With a simple configuration using the rods 41a and 41b and the springs 43a and 43b, a load can be applied to the first recess 33a and the second recess 33b of the pressing member 31. Therefore, the dimensions of the electrode assembly 12 can be easily adjusted.

  (3) With a simple configuration that changes the compression amount of each spring 43a, 43b, the load applied to the first recess 33a and the second recess 33b can be changed separately. Therefore, the dimensions of the electrode assembly 12 can be adjusted more easily.

  (4) While the 1st contact part 42a is made to contact the press member 31 in the 1st recessed part 33a, the 2nd contact part 42b is made to contact the press member 31 in the 2nd recessed part 33b. Therefore, the position where the load is applied can be easily determined.

(5) That is, the load mechanism 34 can be easily positioned with respect to the pressing member 31.
The embodiment is not limited to the above, and may be embodied as follows, for example.
(Circle) the 1st provision mechanism 40a and the 2nd provision mechanism 40b may be provided with elastic bodies, such as rubber | gum, for example instead of a spring, and the structure which can change loads, such as an air cylinder and an oil cylinder, may be sufficient as it.

  A plurality of dimension adjusting devices 30 may be provided for at least one of the pressing member 31 and the supporting member 32. In this case, the dimension adjusting device 30 may have a first applying mechanism 40 a and a second applying mechanism 40 b for each pressing member 31.

(Circle) the dimension adjustment apparatus 30 may be provided with three or more provision mechanisms.
○ At least one of the first recess 33a and the second recess 33b may be omitted.
O The position of the region to which the load is applied may be changed by each of the applying mechanisms 40a and 40b.

  ○ At least one of the pressing member 31 and the support member 32 may extend along the first direction D1 and be disposed across the end surface 12c and the end surface 12d of the electrode assembly 12. That is, the pressing member 31 and the support member 32 may not be arranged so as to extend along the end surface 12c from which the positive electrode tab group 13d and the negative electrode tab group 14d protrude.

○ The shape and size of the pressing member 31 and the supporting member 32 may be changed.
The positive electrode 13 may have an active material layer 13b on one side. Similarly, the negative electrode 14 may have an active material layer 14b on one side.

The electrode assembly 12 may be a wound electrode assembly in which a strip-shaped positive electrode 13 and a strip-shaped negative electrode 14 are wound with a strip-shaped separator 15 interposed therebetween.
The dimension adjustment device 30 may be incorporated in a production line as a production facility for the secondary battery 10. In addition to the size adjusting device 30, the production line includes a device for applying an active material mixture to a metal foil to form an active material layer, a device for laminating the electrodes 13 and 14, and the like.

The secondary battery 10 is not limited to a lithium ion secondary battery, and may be another secondary battery such as a nickel hydrogen secondary battery or a nickel cadmium secondary battery.
O Not only the secondary battery 10, but also a power storage device such as an electric double layer capacitor or a lithium ion capacitor may be used.

The technical idea shown below can be understood from the above embodiment.
(A) The pressing member has a first recess and a second recess, the first region is a region in the first recess, and the second region is in the second recess. A region is preferred.

  (B) The electrode assembly protrudes from an end portion of the end portion of the electrode assembly that is positioned in a direction orthogonal to the overlapping direction of the electrodes and the predetermined direction, and the current collecting tab of the electrode is layered Preferably, the pressing member is disposed along an end portion from which the collecting tab group protrudes.

  (C) It is a manufacturing facility for the power storage device, and preferably includes the dimension adjusting device.

  DS ... stacking direction (overlapping direction), D1 ... first direction (perpendicular direction), D2 ... second direction (perpendicular direction), 10 ... secondary battery (power storage device), 12 ... electrode assembly, 12c ... end face (End part), 12e ... end face (first end part), 12f ... end face (second end part), 13 ... positive electrode (electrode), 13c ... positive electrode tab (current collection tab), 13d ... positive electrode tab group (collection) Electrode tab group), 14 ... Negative electrode (electrode), 14c ... Negative electrode tab (current collection tab), 14d ... Negative electrode tab group (current collection tab group), 30 ... Size adjusting device, 31 ... Pressing member, 33a ... First Recessed portion (first region), 33b ... second recessed portion (second region), 40a ... first applying mechanism, 40b ... second applying mechanism, 41a ... first rod, 41b ... second rod, 42a ... first contact portion 42b ... second contact portion, 43a ... first spring, 43b ... second spring, 47a ... 1 change mechanism, 47b ... second change mechanism.

Claims (2)

A size adjusting device for adjusting the size of an electrode assembly in which a plurality of electrodes are layered,
A pressing member arranged to extend across a first end and a second end located at both ends of a predetermined direction orthogonal to the overlapping direction of the electrodes among the ends of the electrode assembly;
A first applying mechanism for applying a load along the overlapping direction to the first region on the first end portion side of the pressing member;
A second applying mechanism for applying a load along the overlapping direction to the second region on the second end side of the pressing member;
A first changing mechanism for changing a load applied to the first region;
A second changing mechanism for changing a load applied to the second region ,
The first application mechanism includes a first rod having a first contact portion that is in contact with the first region, and a first spring that applies a load to the first rod along the overlapping direction. And
The second application mechanism includes a second rod having a second contact portion that is in contact with the second region, and a second spring that applies a load to the second rod along the overlapping direction. Dimension adjustment device. The first changing mechanism is configured to be able to change a load applied to the first region by changing a compression amount of the first spring.
2. The dimension adjusting device according to claim 1 , wherein the second changing mechanism is configured to be able to change a load applied to the second region by changing a compression amount of the second spring.