Bushing and lead-acid battery

Abstract

To make it possible to suppress leakage by restricting the circumferential rotation of a bushing relative to a lid even in a lead-acid battery with a small bushing attachment area.SOLUTION: A cylindrical bushing 6 fixed to a lid 3 of a lead storage battery 1 includes a seat part 62, a terminal connection part 63 that extends from the seat part 62 and protrudes from the lid 3 of the lead storage battery 1, a fixing part 64 that extends from the seat part 62 to the opposite side of the terminal connection part 63 and is fixed to the lid 3, and a plurality of detent parts 65 that protrudes from the outer circumference of the fixing part 64 and restricts a circumferential D2 rotation of the bushing 6 with respect to the lid part 3. Each of the plurality of detent parts 65 has a detent surface 65c located on one side of the circumferential D2 of the bushing 6. A total area of detent surfaces 65c of the plurality of detent parts 65 is more than 10 mm2.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a bushing and a lead-acid battery. [Background technology]

[0002] Patent Document 1 describes a lead-acid battery to be mounted on automobiles and the like. This lead-acid battery includes a battery case that contains an electrode plate group and an electrolyte, a lid that seals the opening of the battery case, and an electrode terminal. The electrode terminal includes a bushing that is molded integrally with the lid so as to penetrate the lid, and a pole that is inserted into the bushing and welded to the bushing. The bushing is provided with a protrusion (anti-rotation portion) that prevents the bushing from rotating in the circumferential direction relative to the lid. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-118805 A Summary of the Invention [Problem to be solved by the invention]

[0004] A circumferential rotation force is applied to the bushing when a connection terminal such as a harness terminal is attached. When the bushing rotates in the circumferential direction relative to the lid, a gap is generated between the lid and the bushing, and electrolyte may seep out from between the lid and the bushing. By providing a rotation stopper on the bushing, the circumferential rotation of the bushing relative to the lid can be suppressed, but since the lid is made of resin, the circumferential rotation of the bushing relative to the lid cannot be completely prevented.

[0005] Therefore, in the bushing described in Patent Document 1, the anti-rotation portion is a protrusion that protrudes from the outer circumferential surface of the flange (seat portion) of the bushing, that is, the length from the central axis of the bushing to the tip of the anti-rotation portion is increased, thereby further suppressing the bushing from rotating in the circumferential direction. However, since the bushing described in Patent Document 1 is enlarged by having the protrusion protrude from the outer circumferential surface of the flange, it cannot be used for lead-acid batteries, which have a small mounting area for the bushing.

[0006] For this reason, in this technical field, there is a demand for a bushing and a lead-acid battery that can suppress circumferential rotation of the bushing relative to the lid portion and thereby suppress leakage, from a perspective other than increasing the length from the central axis of the bushing to the tip of the anti-rotation portion. [Means for solving the problem]

[0007] [1] The bushing according to the present invention comprises a fixed portion fixed to a lid portion of a lead-acid battery, and a rotation prevention portion protruding from an outer peripheral surface of the fixed portion, the rotation prevention portion having a rotation prevention surface located on one side in a circumferential direction of the fixed portion, and the total area of ​​the rotation prevention surface of the rotation prevention portion is 10 mm 2 It's super.

[0008] This bushing is provided with a rotation prevention portion that protrudes from the outer peripheral surface of the fixed portion that is fixed to the lid portion, and therefore, when the fixed portion is fixed to the lid portion, the bushing can be prevented from rotating in the circumferential direction relative to the lid portion. Here, the inventors conducted extensive research and obtained the following findings. That is, when a force that rotates in the circumferential direction is applied to the bushing, the rotation prevention portion is pressed against the lid portion. It was found that when the area of ​​the surface of the rotation prevention portion that is pressed against the lid portion reaches a predetermined value or more, the frictional force between the lid portion and the rotation prevention portion can prevent the circumferential rotation of the bushing relative to the lid portion. And, since the rotation prevention surface of the rotation prevention portion that is located on one side of the fixed portion in the circumferential direction becomes the surface that is pressed against the lid portion, in this bushing, the total area of ​​the rotation prevention surfaces of the rotation prevention portion is 10 mm 2As a result, even in a lead-acid battery in which the mounting area of ​​the bushing is small, it is possible to suppress rotation of the bushing in the circumferential direction relative to the lid portion and thereby suppress leakage.

[0009] [2] The bushing described in [1] may include a seat and a plurality of anti-rotation portions, the fixing portion extends from the seat, and the diameter of a circumscribing circle of the plurality of anti-rotation portions may be equal to or smaller than the outer diameter of the seat. In this bushing, since the diameter of a circumscribing circle of the plurality of anti-rotation portions is equal to or smaller than the outer diameter of the seat, the length from the central axis of the bushing to the tip of the anti-rotation portion is short. However, if the total area of ​​the anti-rotation surfaces of the anti-rotation portions is less than 10 mm 2 Since the thickness is greater than 1 mm, circumferential rotation of the bushing relative to the lid portion can be suppressed, thereby suppressing leakage.

[0010] [3] A lead-acid battery according to the present invention includes a battery case, a lid, and the bushing according to [1] or [2] fixed to the lid. Since the lead-acid battery includes the bushing, circumferential rotation of the bushing relative to the lid can be suppressed, thereby suppressing leakage.

[0011] [4] The lead-acid battery according to [3] may further include a pole protruding from the lid, and the height position of the upper end of the pole may be lower than the height position of the top surface of the lid. In this lead-acid battery, since the height position of the upper end of the pole is lower than the height position of the top surface of the lid, the distance between the electrolyte and the bushing tends to be short. For this reason, measures against seepage of the electrolyte become more important. Under such circumstances, when the total area of ​​the anti-rotation surface of the anti-rotation portion is 10 mm 2 Therefore, it is more effective to suppress the leakage by suppressing the rotation of the bushing in the circumferential direction relative to the lid portion. This is also true for lead-acid batteries in which the mounting area of ​​the bushing is small. Effect of the Invention

[0012] According to the present invention, the circumferential rotation of the bushing can be suppressed, thereby suppressing leakage. [Brief description of the drawings]

[0013] [Figure 1] 1 is a cross-sectional view showing a lead-acid battery according to an embodiment. [Diagram 2] FIG. 2 is a plan view showing a bushing according to the embodiment. [Diagram 3] FIG. 2 is a front view showing a bushing according to the embodiment. [Figure 4] FIG. 2 is a partial cross-sectional view showing a bushing according to an embodiment. [Diagram 5] 4 is a cross-sectional view taken along line VV shown in FIG. [Figure 6] FIG. 6 is an enlarged cross-sectional view of a portion VI shown in FIG. 5. [Figure 7] FIG. 6 is an enlarged cross-sectional view of a portion VII shown in FIG. 5. [Figure 8] FIG. 11 is a perspective view for explaining an evaluation method. [Figure 9] FIG. 11 is a perspective view for explaining an evaluation method. [Figure 10] FIG. 13 is a plan view for explaining an evaluation method. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of a lead-acid battery and a bushing according to the present invention will be described with reference to the drawings. In the description of the drawings, the same elements are given the same reference numerals, and duplicated description will be omitted.

[0015] Fig. 1 is a cross-sectional view showing a lead-acid battery according to an embodiment. As shown in Fig. 1, the lead-acid battery 1 is a flooded lead-acid battery formed in a substantially cubic shape. The lead-acid battery 1 includes a battery case 2 with an open top, a lid 3 for closing the opening of the battery case 2, a positive terminal 4A, and a negative terminal (not shown). The height direction of the lead-acid battery 1 is referred to as a height direction H.

[0016] The battery case 2 is a resin container with an open top. The material of the battery case 2 is, for example, polypropylene (PP). The battery case 2 contains a plurality of electrode plates 21, a positive electrode strap 22A connecting the positive electrodes of the plurality of electrode plates 21, a negative electrode strap 22B connecting the negative electrodes of the plurality of electrode plates 21, an electrolyte 23, and the like.

[0017] The lid 3 is a resin lid that is joined to the battery case 2 to close the opening of the battery case 2. The material of the lid 3 is, for example, polypropylene (PP).

[0018] The positive electrode terminal 4A is a metal electrode terminal that electrically connects the positive electrodes of the multiple electrode plates 21 to an external device. The positive electrode terminal 4A is electrically connected to the positive electrodes of the multiple electrode plates 21 by positive electrode straps 22A. The negative electrode terminal is a metal electrode terminal that electrically connects the negative electrodes of the multiple electrode plates 21 to an external device. The negative electrode terminal is electrically connected to the negative electrodes of the multiple electrode plates 21 by negative electrode straps 22B. Note that the positive electrode terminal 4A and the negative electrode terminal basically have the same configuration, and therefore will be collectively described as the "electrode terminal 4" unless otherwise specified.

[0019] The electrode terminal 4 has a pole 5 and a bushing 6. The pole 5 of the positive terminal 4A is connected to a positive strap 22A. The pole 5 of the positive terminal 4A is erected on the positive strap 22A and is formed in a tapered rod shape. The pole (not shown) of the negative terminal is connected to a negative strap 22B. The pole of the negative terminal is erected on the negative strap 22B and is formed in a tapered rod shape. The material of the pole 5 is, for example, a lead alloy.

[0020] The height position of the upper end 5a of the electrode post 5 is lower than the height position of the top surface 3a of the lid portion 3. The height position of the upper end 5a of the electrode post 5 is the highest position of the electrode terminal 4 in the height direction H. The top surface 3a of the lid portion 3 is the surface that is at the highest position of the lid portion 3 in the height direction H, and the height position of the top surface 3a of the lid portion 3 is the highest position of the lid portion 3 in the height direction H.

[0021] FIG. 2 is a plan view showing a bushing according to an embodiment. FIG. 3 is a front view showing a bushing according to an embodiment. FIG. 4 is a partial cross-sectional view showing a bushing according to an embodiment. FIG. 5 is a cross-sectional view taken along line VV shown in FIG. 3. As shown in FIGS. 1 to 4, the bushing 6 is fixed to the cover 3. The pole 5 is inserted into the bushing 6 and fixed thereto. The bushing 6 is formed in a cylindrical shape, and an insertion hole 61 into which the pole 5 is inserted is formed on its inner circumferential surface. The direction along the central axis A of the bushing 6 is referred to as the axial direction D1, and the direction around the central axis A of the bushing 6 (circumferential direction) is referred to as the circumferential direction D2. In addition, the direction on one side of the axial direction D1 is referred to as the first axial direction D11, and the direction on the other side is referred to as the second axial direction D12. The first axial direction D11 is, for example, a direction toward the top of the lead-acid battery 1, and the second axial direction D12 is, for example, a direction toward the bottom of the lead-acid battery 1. In addition, one side of the circumferential direction D2 is referred to as a first circumferential direction D21, and the other side is referred to as a second circumferential direction D22. The first circumferential direction D21 is, for example, a clockwise direction in a plan view of the lead-acid battery 1, and the second circumferential direction D22 is a counterclockwise direction in a plan view of the lead-acid battery 1. The insertion hole 61 extends along the axial direction D1. The material of the bushing 6 is, for example, a lead alloy. The bushing 6 can be fixed to the lid portion 3 by, for example, insert molding, in which resin is injected into a mold in which the bushing 6 is arranged. The pole 5 can be fixed to the bushing 6 by, for example, welding.

[0022] The bushing 6 includes a seat portion 62 , a fixing portion 64 , and a plurality of anti-rotation portions 65 .

[0023] The seat 62 is formed in an annular shape and is a portion located in the center of the bushing 6 in the axial direction D1. The seat 62 forms the maximum diameter of the bushing 6. That is, the bushing 6 has the maximum diameter at the seat 62. A part or all of the outer circumferential surface of the seat 62 is covered by the lid 3, and the seat 62 is fixed to the lid 3 so that a part or all of the outer circumferential surface is embedded in the lid 3. Of both sides of the seat 62 in the axial direction D1, the surface facing upward of the lead-acid battery 1 (the surface on the first axial direction D11 side) is referred to as the upper seat surface 62a, and the surface facing downward of the lead-acid battery 1 (the surface on the second axial direction D12 side) is referred to as the lower seat surface 62b.

[0024] The terminal connection portion 63 protrudes from the cover portion 3 and is a portion to which a connection terminal (not shown) such as a harness terminal is attached. The terminal connection portion 63 is formed in a cylindrical shape and extends in the first axial direction D11 from the upper seating surface 62a of the seating portion 62. The terminal connection portion 63 becomes thinner toward the tip.

[0025] The fixing portion 64 is a portion that is fixed to the lid portion 3. The fixing portion 64 is formed in a cylindrical shape, and extends from the seat portion 62 in a direction opposite to the terminal connection portion 63, that is, from a lower seating surface 62b of the seat portion 62 in the second axial direction D12. A part or all of the outer circumferential surface of the fixing portion 64 is covered by the lid portion 3, and the fixing portion 64 is fixed to the lid portion 3 such that a part or all of the outer circumferential surface of the fixing portion 64 is embedded in the lid portion 3. In this embodiment, a front part of the outer circumferential surface of the fixing portion 64 is covered by the lid portion 3.

[0026] One or more annular ribs 66 are formed on the outer peripheral surface of the fixing part 64. The annular ribs 66 are intended to lengthen the permeation path of the electrolyte 23 between the cover part 3 and the bushing 6 in order to suppress leakage of the electrolyte 23. The outer diameter d1 of the annular rib 66 is smaller than the outer diameter d2 of the seat part 62. The one or more annular ribs 66 are arranged spaced apart from the seat part 62. When a plurality of annular ribs 66 are formed on the outer peripheral surface of the fixing part 64, the plurality of annular ribs 66 are arranged spaced apart from each other. The one or more annular ribs 66 are not cut out, for example, from the viewpoint of ease of manufacture, and have the same cross-sectional shape over the entire area in the circumferential direction D2 of the fixing part 64. In the bushing 6 shown in FIG. 1 to FIG. 4, three annular ribs 66 are arranged at equal intervals in the axial direction D1.

[0027] From the viewpoint of miniaturizing the bushing 6, the outer diameter d3 of the fixing portion 64 immediately below the seat portion 62 is, for example, 18.0 mm or less, 17.0 mm or less, 16.0 mm or less, or 15.0 mm or less. If the annular rib 66 is not formed immediately below the seat portion 62, this outer diameter d3 becomes the outer diameter of the fixing portion 64 immediately below the seat portion 62. If the annular rib 66 is formed immediately below the seat portion 62, this outer diameter d3 becomes the outer diameter of the annular rib 66 immediately below the seat portion 62.

[0028] The multiple anti-rotation portions 65 protrude from the outer circumferential surface of the fixed portion 64 and are portions that suppress rotation of the bushing 6 in the circumferential direction D2 relative to the cover portion 3. By protruding from the outer circumferential surface of the fixed portion 64, the multiple anti-rotation portions 65 are caught on the cover portion 3 in the circumferential direction D2 of the bushing 6. In this way, the multiple anti-rotation portions 65 suppress rotation of the bushing 6 in the circumferential direction D2 relative to the cover portion 3.

[0029] The number, position, shape, size, etc. of the multiple anti-rotation portions 65 are not particularly limited.

[0030] For example, the anti-rotation portion 65 may be provided in a location where the annular rib 66 is not formed, or may be provided on the annular rib 66, or may be provided from a location where the annular rib 66 is not formed to onto the annular rib 66. The anti-rotation portion 65 may be connected to (adjacent to) the seat portion 62, or may be spaced apart from the seat portion 62. One or more anti-rotation portions 65 may be provided in the circumferential direction D2, or one or more anti-rotation portions 65 may be provided in the axial direction D1.

[0031] From the viewpoint of miniaturizing the bushing 6, the diameter d4 of the circumscribing circle C of the anti-rotation portions 65 may be equal to or smaller than the outer diameter d2 of the seat portion 62. The circumscribing circle C of the anti-rotation portions 65 is the circumscribing circle of the anti-rotation portions 65 in a plan view of the bushing 6 (see FIGS. 2 and 5). The diameter d4 of the circumscribing circle C of the anti-rotation portions 65 may be equal to or smaller than 25.0 mm, 24.0 mm, 23.0 mm, 22.0 mm, or 21.0 mm. From the viewpoint of making it easier to ensure the total area of ​​the anti-rotation surfaces 65c of the anti-rotation portions 65 (see FIGS. 6 and 7) while miniaturizing the bushing 6, the diameter d4 of the circumscribing circle C of the anti-rotation portions 65 may be equal to or larger than 20.5 mm.

[0032] In the bushing 6 shown in Figs. 1 to 4, only four anti-rotation portions 65a and four anti-rotation portions 65b are provided as the multiple anti-rotation portions 65. The four anti-rotation portions 65a are formed in a substantially rectangular shape in a cross section perpendicular to the axial direction D1. The four anti-rotation portions 65b are formed in a substantially triangular shape in a cross section perpendicular to the axial direction D1. The four anti-rotation portions 65a and the four anti-rotation portions 65b are alternately arranged in the circumferential direction D2. The four anti-rotation portions 65a and the four anti-rotation portions 65b are connected to the lower seating surface 62b of the seat 62. The four anti-rotation portions 65a and the four anti-rotation portions 65b extend in the second axial direction D12 from the lower seating surface 62b of the seat 62 through a portion immediately below the seat 62 where the annular rib 66 is not formed, to the annular rib 66 adjacent to the portion.

[0033] Here, the inventors conducted intensive research and obtained the following knowledge: When a rotational force in the circumferential direction D2 is applied to the bushing 6, the anti-rotation portions 65 are pressed against the cover portion 3. It was found that when the area of ​​the surfaces of the anti-rotation portions 65 pressed against the cover portion 3 reaches a predetermined value or more, the frictional force between the cover portion 3 and the anti-rotation portions 65, etc., can suppress the rotation of the bushing 6 in the circumferential direction D2 relative to the cover portion 3.

[0034] Each of the multiple anti-rotation portions 65 has a anti-rotation surface 65c located on one side in the circumferential direction D2. The anti-rotation surface 65c is a surface that is pressed against the cover portion 3 when a force that rotates the bushing 6 toward one side in the circumferential direction D2 is applied to the bushing 6, and is a surface located on the front side in the rotation direction of the bushing 6. Here, since a rotation force may be applied to the bushing 6 in any direction in the circumferential direction D2, the anti-rotation surface 65c may be a surface on the first circumferential direction D21 side of each of the multiple anti-rotation portions 65, or may be a surface on the second circumferential direction D22 side of each of the multiple anti-rotation portions 65. Note that, in the drawings, as an example, the surface on the first circumferential direction D21 side of each of the multiple anti-rotation portions 65 is shown as the anti-rotation surface 65c.

[0035] Fig. 6 is an enlarged cross-sectional view of a portion VI shown in Fig. 5. Fig. 7 is an enlarged cross-sectional view of a portion VII shown in Fig. 5. In Figs. 6 and 7, the anti-rotation surface 65c is indicated by a thick line. As shown in Figs. 5 to 7, the anti-rotation surface 65c may be a surface perpendicular to the circumferential direction D2, or may be a surface inclined with respect to the circumferential direction D2. In addition, the anti-rotation surface 65c may be a flat surface, a curved surface, or a bent surface.

[0036] The total area of ​​the anti-rotation surfaces 65c of the anti-rotation portions 65 is 10 mm 2 The total area of ​​the anti-rotation surfaces 65c of the anti-rotation portions 65 is the sum of the areas of the anti-rotation surfaces 65c of the anti-rotation portions 65. 2 Ultra means 10mm 2The total area of ​​the anti-rotation surfaces 65c of the anti-rotation portions 65 is 40 mm 2 Above, 60mm 2 or more, or 70mm 2 In both cases where the surface of each of the plurality of anti-rotation portions 65 on the first circumferential direction D21 side is the anti-rotation surface 65c and where the surface of each of the plurality of anti-rotation portions 65 on the second circumferential direction D22 side is the anti-rotation surface 65c, it is preferable that the total area of ​​the anti-rotation surfaces 65c of the plurality of anti-rotation portions 65 is in the above-mentioned range, but in only one of the cases, the total area of ​​the anti-rotation surfaces 65c of the plurality of anti-rotation portions 65 may be in the above-mentioned range.

[0037] In this manner, the bushing 6 according to this embodiment includes a plurality of anti-rotation portions 65 protruding from the outer circumferential surface of the fixing portion 64 fixed to the lid portion 3, so that when the fixing portion 64 is fixed to the lid portion 3, the bushing 6 can be prevented from rotating in the circumferential direction D2 relative to the lid portion 3. In addition, when the total area of ​​the anti-rotation surfaces 65c of the plurality of anti-rotation portions 65 is 10 mm 2 Super, 40mm 2 Above, 60mm 2 or more, or 70mm 2 For the above reasons, even in a lead-acid battery 1 in which the mounting area of ​​the bushing 6 is small, rotation of the bushing 6 relative to the lid portion 3 in the circumferential direction D2 can be suppressed, thereby suppressing leakage.

[0038] In addition, in this bushing 6, since the outer diameter of the fixing portion 64 directly below the seat portion 62 is 18.0 mm or less, 17.0 mm or less, 16.0 mm or less, or 15.0 mm or less, the lead-acid battery 1 to which the bushing 6 is applied is likely to be small. However, when the total area of ​​the anti-rotation surfaces 65c of the multiple anti-rotation portions 65 is less than 10 mm 2 Super, 40mm 2 Above, 60mm 2 or more, or 70mm 2 For the above reasons, rotation of the bushing 6 relative to the lid portion 3 in the circumferential direction D2 can be suppressed, thereby suppressing leakage.

[0039] In addition, in this bushing 6, the diameter d4 of the circumscribed circle C of the anti-rotation portions 65 is equal to or smaller than the outer diameter d1 of the seat portion 62, 25.0 mm or less, 24.0 mm or less, 23.0 mm or less, 22.0 mm or less, or 21.0 mm or less, so that the length from the central axis A of the bushing 6 to the tip of the anti-rotation portion 65 is short. However, when the total area of ​​the anti-rotation surfaces 65c of the anti-rotation portions 65 is less than 10 mm 2 Super, 40mm 2 Above, 60mm 2 or more, or 70mm 2 For the above reasons, rotation of the bushing 6 relative to the lid portion 3 in the circumferential direction D2 can be suppressed, thereby suppressing leakage.

[0040] The lead-acid battery 1 according to this embodiment includes the above-mentioned bushing 6, and therefore rotation of the bushing 6 relative to the lid portion 3 in the circumferential direction D2 can be suppressed, thereby suppressing leakage.

[0041] In addition, in this lead-acid battery 1, the height position of the upper end 5a of the pole 5 is lower than the height position of the top surface 3a of the lid portion 3, so the distance between the electrolyte and the bushing 6 tends to be short. For this reason, measures against the seepage of the electrolyte become more important. Under such circumstances, when the total area of ​​the anti-rotation surfaces 65c of the multiple anti-rotation portions 65 is less than 10 mm 2 Therefore, it is more effective to suppress the leakage by suppressing the rotation of the bushing 6 in the circumferential direction D2 relative to the lid portion 3. This is also true for the lead-acid battery 1 in which the mounting area of ​​the bushing 6 is small.

[0042] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. EXAMPLES

[0043] Examples of the present invention will be described below, but the present invention is not limited to these examples.

[0044] Example 1 A bushing with eight anti-rotation parts and three annular ribs was fabricated. In this bushing, the total area of ​​the anti-rotation surfaces of the eight anti-rotation parts is 85 mm 2 The outer diameter of the seat was 25.0 mm, the outer diameter of the fixing portion directly below the seat was 14.0 mm, and the diameter of the circumscribed circle of the eight anti-rotation portions was 20.6 mm.

[0045] Example 2 A bushing with eight anti-rotation parts and three annular ribs was fabricated. In this bushing, the total area of ​​the anti-rotation surfaces of the eight anti-rotation parts is 65 mm 2 The outer diameter of the seat was 25.0 mm, the outer diameter of the fixing part directly below the seat was 17.3 mm, and the diameter of the circumscribed circle of the eight anti-rotation parts was 25.0 mm.

[0046] Example 3 A bushing with eight anti-rotation parts and three annular ribs was fabricated. In this bushing, the total area of ​​the anti-rotation surfaces of the eight anti-rotation parts is 62 mm 2 The outer diameter of the seat was 25.0 mm, the outer diameter of the fixing part directly below the seat was 18.5 mm, and the diameter of the circumscribed circle of the eight anti-rotation parts was 23.0 mm.

[0047] Example 4 A bushing with six anti-rotation parts and one annular rib was fabricated. In this bushing, the total area of ​​the anti-rotation surfaces of the six anti-rotation parts is 34 mm 2 The outer diameter of the seat was 28.3 mm, the outer diameter of the fixed portion directly below the seat was 21.5 mm, and the diameter of the circumscribed circle of the six anti-rotation portions was 23.0 mm.

[0048] Example 5 A bushing with four anti-rotation parts and four annular ribs was fabricated. In this bushing, the total area of ​​the anti-rotation surfaces of the four anti-rotation parts was 29 mm 2 The outer diameter of the seat was 23.8 mm, the outer diameter of the fixing portion directly below the seat was 14.0 mm, and the diameter of the circumscribed circle of the four anti-rotation portions was 23.8 mm.

[0049] Example 6 A bushing with four anti-rotation parts and four annular ribs was fabricated. In this bushing, the total area of ​​the anti-rotation surfaces of the four anti-rotation parts is 13 mm 2 The outer diameter of the seat was 25.0 mm, the outer diameter of the fixing part directly below the seat was 18.5 mm, and the diameter of the circumscribed circle of the four anti-rotation parts was 21.5 mm.

[0050] Example 7 A bushing with four anti-rotation parts and three annular ribs was fabricated. In this bushing, the total area of ​​the anti-rotation surfaces of the four anti-rotation parts is 13 mm 2 The outer diameter of the seat was 25.0 mm, the outer diameter of the fixing part directly below the seat was 18.5 mm, and the diameter of the circumscribed circle of the four anti-rotation parts was 21.5 mm.

[0051] Comparative Example 1 A bushing with four anti-rotation parts and three annular ribs was fabricated. In this bushing, the total area of ​​the anti-rotation surfaces of the four anti-rotation parts is 10 mm 2 The outer diameter of the seat was 23.0 mm, the outer diameter of the fixed portion directly below the seat was 17.5 mm, and the diameter of the circumscribed circle of the four anti-rotation portions was 20.0 mm.

[0052] (evaluation) The strength of the bushing was evaluated in the lead-acid batteries using the bushings of Examples 1 to 7 and Comparative Example 1. FIGS. 8 and 9 are perspective views for explaining the evaluation method. FIG. 10 is a plan view for explaining the evaluation method. In the evaluation, first, as shown in FIG. 8, a reference line was drawn from the upper seating surface of the bushing seating portion to the lid portion continuing to the upper seating surface. Next, as shown in FIG. 9, the bushing was rotated in the first circumferential direction D21, and the deviation between the reference line drawn on the upper seating surface of the bushing seating portion and the reference line drawn on the lid portion was measured. The deviation was taken as the linear distance in a plan view between the tip of the reference line drawn on the upper seating surface on the lid portion side and the tip of the reference line drawn on the lid portion on the upper seating surface side, as shown in FIG. 10. Then, when the deviation was 0.10 mm or less, it was evaluated as A, when the deviation was more than 0.10 mm and less than 0.16 mm, it was evaluated as B, and when the deviation was more than 0.16 mm, it was evaluated as C. The evaluation results are shown in Table 1.

[0053] [Table 1]

[0054] As shown in Table 1, the total area of ​​the anti-rotation surfaces is 10 mm 2 Comparative Example 1 was rated C, but the total area of ​​the anti-rotation surface was 10 mm 2 Examples 1 to 7, which are greater than 10 mm2, were evaluated as A or B. 2 It is presumed that by exceeding this limit, circumferential rotation of the bushing relative to the lid portion can be suppressed, thereby suppressing leakage.

[0055] In addition, the total area of ​​the anti-rotation surfaces is 34 mm 2 The following Examples 4 to 7 were rated B, but the total area of ​​the anti-rotation surfaces was 34 mm 2 More than 100 Examples 1 to 3 were rated as A. From these results, it is clear that the total area of ​​the anti-rotation surfaces is at least 40 mm 2 As a result, it is presumed that circumferential rotation of the bushing relative to the lid portion can be further suppressed, thereby further suppressing leakage. [Explanation of symbols]

[0056] 1...lead-acid battery, 2...case, 3...lid, 4...electrode terminal, 4A...positive terminal, 5...pole, 6...bushing, 21...electrode plate, 22A...positive strap, 22B...negative strap, 23...electrolyte, 61...insertion hole, 62...seat, 62a...upper seat surface, 62b...lower seat surface, 63...terminal connection portion, 64...fixing portion, 65...anti-rotation portion, 65a...anti-rotation portion, 65b...anti-rotation portion, 65c...anti-rotation surface, 66...annular rib, A...center axis, C...circumscribed circle, D1...axial direction, D11...first axial direction, D12...second axial direction, D2...circumferential direction, D21...first circumferential direction, D22...second circumferential direction, d1...outer diameter, d2...outer diameter, d3...outer diameter, d4...diameter.

Claims

1. A fixing portion fixed to a lid portion of a lead-acid battery; A rotation prevention portion protruding from an outer circumferential surface of the fixing portion, The anti-rotation portion has a anti-rotation surface located on one side in a circumferential direction of the fixed portion, The total area of ​​the anti-rotation surfaces is 10 mm ２ It is super Bushing.

2. A seat portion, A plurality of the anti-rotation portions, The fixing portion extends from the seat portion, The diameter of a circumscribing circle of the plurality of anti-rotation portions is equal to or smaller than the outer diameter of the seat portion.

2. The bushing of claim 1.

3. A battery case and A lid portion; The bushing according to claim 1 or 2 is fixed to the lid portion. Lead acid battery.

4. The housing further includes a pole protruding from the lid, The height position of the upper end of the pole is lower than the height position of the top surface of the lid.

4. The lead-acid battery according to claim 3.

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