On-vehicle battery

Abstract

To provide an on-vehicle battery in which the damage due to an external input is suppressed.SOLUTION: An on-vehicle battery according to the art disclosed herein includes a case 30, an electrode body 2 incorporated in the case 30 and having a positive electrode and a negative electrode, a positive terminal member 5 disposed in the case 30 and connected to the positive electrode, and a negative terminal member 6 disposed in the case 30 and connected to the negative electrode. In at least one of the positive terminal member 5 and the negative terminal member 6, an outward surface 52 facing outside is provided, and a hole 53 in a direction to the inside is formed on the outward surface 52. An external terminal member 7 is inserted into the hole 53 from the outside. The external terminal member 7 includes an insertion part inserted into the hole 53, and an external connection part provided connecting to the outside with respect to the insertion part. The insertion part includes a branch section that is branched into a plurality of branch parts, and each branch part is in close contact with a wall surface 54 of the hole 53.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The disclosed technology relates to in-vehicle batteries.

Background Art

[0002] As an example of a conventional in-vehicle battery, the "electric storage element" described in Patent Document 1 can be cited. In the electric storage element of this document, a part of the electrode terminal is provided so as to protrude from the container. A recess is formed on the upper surface of the protruding portion. A conductive portion of an annular elastic body is disposed in the recess. Through the conductive portion, the electrode terminal and an external conductor are electrically connected. Insulating members are provided on the upper surface and side surface of the protruding portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The above-described conventional battery has a problem of being vulnerable to external mechanical input. For a battery used for in-vehicle applications, foreign objects such as flying stones may fly in during driving. Such foreign objects are likely to hit the electrode terminal protruding from the container. Therefore, the electrode terminal may be damaged.

[0005] The problem of the disclosed technology is to provide an in-vehicle battery that is less likely to be damaged by external input.

Means for Solving the Problems

[0006] In one aspect of the disclosed technology, an in-vehicle battery includes a case and an electrode body housed in the case and having a positive electrode and a negative electrode. The battery has a positive terminal member disposed inside the case and connected to the positive electrode, and a negative terminal member disposed inside the case and connected to the negative electrode. At least one of the positive terminal member and the negative terminal member is provided with an outward-facing surface facing outward, and a hole is formed in the outward-facing surface in a direction facing inward. An external terminal member is inserted into the hole from the outside. The external terminal member has an insertion portion inserted into the hole and an external connection portion provided to extend outward from the insertion portion. The insertion portion has a branched section branched into a plurality of branch portions, and each branch portion is in close contact with the wall surface of the hole.

[0007] In the in-vehicle battery according to the above aspect, the positive and negative terminal members are arranged without protruding from the case. The external terminal member inserted into the hole formed in the terminal member from the outside conducts electricity between the electrode body and the outside. In the hole, the branch portions of the branched section, which is a part of the external terminal member, are in close contact with the wall surface of the hole. As a result, the terminal member arranged without protruding from the case is protected from external input and is less likely to be damaged.

[0008] Furthermore, in the in-vehicle battery according to the above aspect, it is preferable that an insulating portion is provided between the outward-facing surface and the external connection portion, and the insulating portion is provided so as to surround a portion between the insertion portion and the external connection portion of the external terminal member. The insulating portion insulates between the terminal member and the case. Also, excessive descent of the external connection portion is prevented.

[0009] Furthermore, in the in-vehicle battery according to any of the above aspects, it is desirable that the insertion portion has a merging section that does not branch on the tip side of the branched section. In this case, it is easy to insert the tip of the insertion portion into the hole.

[0010] In the in-vehicle battery according to the foregoing aspect or an aspect having an insulating portion, or the insertion portion is a cylindrical member, and a section including the inner-facing end portion is a branching section, and a section outside the branching section is an integral section that is not branched, and it may have an axial member press-fitted from the outside with respect to the integral section. In this case, by further pushing in the axial member, the branched portion of the branching section expands in diameter and adheres to the wall surface of the hole.

[0011] In the in-vehicle battery in which the insertion portion is a cylindrical member, it is further desirable that the hole is a bottomed hole. In this case, not only is the sealing property of the internal space of the battery ensured, but also the diameter expansion of the branching section by further pushing in the axial member is reliable.

Advantages of the Invention

[0012] According to the disclosed technology, an in-vehicle battery that is less likely to be damaged by external input is provided.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0014] The first embodiment embodies the disclosed technology as the battery 1 shown in FIGS. 1 and 2. The battery 1 has an electrode body 2 built in a rectangular flat case 30. The case 30 has a flat lid body 31 and a box-shaped box body 32. The electrode body 2 is formed by laminating a positive electrode plate 3 and a negative electrode plate 4 together with an electrolyte. The battery 1 is for in-vehicle use.

[0015] Inside the case 30 of the battery 1, in addition to the electrode body 2, a positive terminal member 5 and a negative terminal member 6 are arranged. The positive terminal member 5 is a conductive member connected to the positive electrode plate 3. The positive terminal member 5 is composed of a current collecting portion 50 and a terminal portion 51. The negative terminal member 6 is a conductive member connected to the negative electrode plate 4. The negative terminal member 6 is composed of a current collecting portion 60 and a terminal portion 61.

[0016] The positive terminal member 5 will be further described. The current collecting portion 50 is the portion connected to the positive electrode plate 3. The terminal portion 51 is the portion for external connection. The current collecting portion 50 and the terminal portion 51 are connected. The positive terminal member 5 may be a single part as a whole of the current collecting portion 50 and the terminal portion 51, or the current collecting portion 50 and the terminal portion 51 may be separate parts joined together.

[0017] In FIG. 2, the terminal portion 51 is above the electrode body 2 and is located near the bottom of the lid body 31. An outward-facing surface 52 is provided on the terminal portion 51. The outward-facing surface 52 is an upward-facing surface in FIG. 2. The height position of the outward-facing surface 52 in FIG. 2 is approximately the same as the back surface 33 of the lid body 31. The outward-facing surface 52 is an outward-facing surface of the battery 1. A hole 53 is formed in the outward-facing surface 52. The hole 53 is a recess dug in the direction from the outward-facing surface 52 toward the inside. The hole 53 is a bottomed hole having a wall surface 54 and a bottom surface 55.

[0018] The same can be said for the current collecting portion 60 and the terminal portion 61 of the negative terminal member 6 as for the current collecting portion 50 and the terminal portion 51 of the positive terminal member 5. An outward-facing surface 62 and a hole 63 are also provided on the terminal portion 61. In FIG. 2, the case 30 and the terminal portions 51 and 61 are shown as cross-sectional views.

[0019] The lid 31 is formed with a through hole 34 and a through hole 35. In FIG. 2, the through hole 34 is located above the terminal portion 51, and the through hole 35 is located above the terminal portion 61. Regarding the horizontal size in FIG. 2, the through hole 34 is larger than the terminal portion 51, and the through hole 35 is larger than the terminal portion 61. The same applies to the size in the direction perpendicular to the plane of FIG. 2. Therefore, neither the terminal portion 51 nor the terminal portion 61 is in contact with the lid 31.

[0020] An insulating member 36 is attached to both the through hole 34 and the through hole 35. The insulating member 36 is provided with a through hole 37. The through hole 37 is located above the holes 53 and 63. The outer surface 38 of the insulating member 36 is in close contact with the wall surfaces of the through holes 34 and 35 of the lid 31. The back surface 39 of the insulating member 36 is in contact with the outward-facing surface 52 of the terminal portion 51 and the outward-facing surface 62 of the terminal portion 61. The insulating member 36 fills the gaps between the lid 31 and the terminal portion 51, and between the lid 31 and the terminal portion 61. The insulating member 36 constitutes an insulating portion that insulates the lid 31 from the terminal portion 51 and insulates the lid 31 from the terminal portion 61.

[0021] An external terminal member 7 is attached to each of the terminal portion 51 and the terminal portion 61. In FIG. 2, the state before the external terminal member 7 is attached to the left terminal portion 51 and the state where the external terminal member 7 is attached to the right terminal portion 61 are respectively shown. In FIG. 1, the state where the external terminal member 7 is not attached to both terminal portions is shown.

[0022] By pushing the external terminal member 7 downward against the terminal portion 51 or the terminal portion 61 before attachment, the external terminal member 7 is attached to the battery 1. In the state before the external terminal member 7 is attached, the space in the hole 53 is connected to the outside through the through hole 37. In the state where the external terminal member 7 is attached, the space in the hole 63 is blocked from the outside by the external terminal member 7.

[0023] The external terminal member 7 will be described. As shown in FIG. 3, the external terminal member 7 has an insertion portion 8 and an external connection portion 9. The insertion portion 8 is the portion inserted into the hole 63 in the mounting state on the right side of FIG. 2. The external connection portion 9 is the portion located outside the hole 63 even in the mounting state. The external connection portion 9 is provided so as to be connected to the outer side of the battery 1 with respect to the insertion portion 8. The external connection portion 9 is a portion for electrical connection between the battery 1 and other devices. Other devices include other batteries.

[0024] A partial section in the longitudinal direction of the insertion portion 8 is a branching section 81 that branches into a plurality of branch portions 80. There is a slit 82 between the branch portions 80. The tip side of the insertion portion 8 beyond the branching section 81 is a non-branching merging section 83. The portion between the insertion portion 8 and the external connection portion 9 in the external terminal member 7 is called a neck portion 84. The external connection portion 9 is wider than the neck portion 84.

[0025] The external terminal member 7 is formed by processing a plate-shaped metal member having a wide portion and a narrow portion. A longitudinal cut is made in a part of the narrow portion of the metal member, and the cut is widened in the width direction to form the slit 82. The wide portion is the external connection portion 9, and the narrow portions are the insertion portion 8 and the neck portion 84.

[0026] The branching section 81 is wider than the neck portion 84 and the merging section 83. This is because the slit 82 is widened as described above. The connection portions of the plurality of branch portions 80 have elasticity, and for this reason, the branching section 81 acts substantially as a leaf spring in the width direction. Therefore, the width W1 of the branching section 81 is somewhat stretchable. When the branching section 81 is compressed in the width direction, the width W1 slightly decreases. In the external terminal member 7 in the free state before being attached to the terminal portion 51 or the terminal portion 61, the width W1 is slightly larger than the diameter R (see FIG. 4) of the holes 53 and 63.

[0027] The attachment of the external terminal member 7 is performed with the insertion portion 8 facing downward. In this posture, when the external terminal member 7 is pushed downward against the terminal portion 51 or the terminal portion 61, the insertion portion 8 enters the holes 53 and 63 via the through hole 37 of the insulating member 36. Since the tip of the insertion portion 8 is the non-branching confluence section 83, it is easy to insert. When the lower side of the external connection portion 9 contacts the insulating member 36, the external terminal member 7 cannot be pushed further. This state is the attached state of the external terminal member 7. Even in the attached state, the external connection portion 9 does not contact the lid 31 outside the insulating member 36.

[0028] Upon this entry, the branching section 81 is slightly compressed in the width direction. This is due to the relationship between the aforementioned width W1 and the diameter R. Therefore, in the attached external terminal member 7, the branching section 81 is in a state of being compressed in the width direction by the wall surfaces 54 of the holes 53 and 63. Due to the reaction force of this compression, in the branching section 81, the outer sides of the outermost ones of the branch portions 80 in the width direction are in close contact with the wall surface 54. Therefore, the electrical conductivity between the external terminal member 7 and the terminal portions 51 and 61 is good.

[0029] In the attached state, the insulating member 36 surrounds the portion of the neck portion 84 in the external terminal member 7. Therefore, the insulation between the positive and negative external terminal members 7 is reliable. Also in the attached state, the insulating member 36 is located between the outward-facing surfaces 52 and 62 of the terminal portions 51 and 61 and the external connection portion 9. Therefore, the insulating member 36 prevents excessive descent of the external terminal member 7.

[0030] The battery 1 configured as described above has the advantage that it is less likely to be damaged by external input. This is because the positive terminal member 5 and the negative terminal member 6 do not protrude outward. The outermost portions of the positive terminal member 5 and the negative terminal member 6 are the outward-facing surfaces 52 and the outward-facing surface 62. These are at the same level as the back surface 33 of the lid 31 and there is no portion that protrudes further outward than the lid 31.

[0031] Therefore, even when foreign objects such as flying stones during driving fly towards the battery 1, it is highly unlikely that the foreign objects will hit the positive terminal member 5 or the negative terminal member 6. Among the external terminal members 7, the external connection portion 9 may be deformed when hit by a foreign object, but it is highly unlikely that the deformation will affect the positive terminal member 5 or the negative terminal member 6. It is easy to replace the deformed external terminal member 7 with a new external terminal member 7. In this way, the battery 1 is less likely to be damaged by external input.

[0032] Among the external terminal members 7, the external connection portion 9 may also serve as a bus bar in the battery stack. That is, two insertion portions 8 may be provided on a metal member straddling one positive terminal member 5 and the other negative terminal member 6 of adjacent batteries in the battery stack.

[0033] The second form according to the disclosed technology will be described with reference to FIGS. 5 to 7. The external terminal member 17 shown in FIGS. 5 and 6 is composed of a cylindrical member 18 and an axial member 20. The cylindrical member 18 is a cylindrical metal member with a hole 21 formed at the center. The axial member 20 is a rod-shaped metal member inserted into the hole 21 of the cylindrical member 18. The external terminal member 17 can be replaced with the external terminal member 7 in the above-described form.

[0034] As shown in FIG. 5, a notch 19 is provided near the lower end of the cylindrical member 18. The section of the cylindrical member 18 where the notch 19 is located can be said to be a section that branches into a plurality of branch portions 80. The section of the cylindrical member 18 where the notch 19 is located corresponds to the branch section 81. The portion of the cylindrical member 18 above the branch section 81, that is, the portion outside the branch section 81 in the attached state to the battery 1, is an integral section 22 that does not branch.

[0035] Before being inserted into the cylindrical member 18, the axial member 20 has a diameter slightly larger than that of the hole 21. The axial member 20 is press-fitted into the hole 21 of the cylindrical member 18 from above. In the state shown in FIGS. 5 and 6, the axial member 20 is inserted into the hole 21 to such an extent that its lower end does not reach the branching section 81. The outer diameter of the cylindrical member 18 is smaller than the diameter R of the holes 53 and 63. In the external terminal member 17 in this state, the entire cylindrical member 18 corresponds to the insertion portion 8. The external terminal member 17 is not provided with a portion corresponding to the confluence section 83.

[0036] Similar to the aforementioned external terminal member 7, the external terminal member 17 of the second form is also attached to and used in the holes 53 and 63 of the terminal portions 51 and 61. When attaching, the branching section 81 at the lower end comes first and the cylindrical member 18 enters the holes 53 and 63. In the external terminal member 17, after inserting the cylindrical member 18 into the holes 53 and 63, the diameter of the branching section 81 is further increased. Specifically, the axial member 20 is further pushed downward. At this time, the cylindrical member 18 cannot descend further because the lower end of the cylindrical member 18 is restricted by the bottom surfaces 55 and 65 of the holes 53 and 63.

[0037] When the lower end of the axial member 20 enters the branching section 81, as shown in FIG. 7, the cut 19 opens and each branch portion 80 becomes inclined. In this state, each branch portion 80 is deformed in a direction in which the diameter as the cylindrical member 18 expands, as compared with the state of FIG. 6 before pushing in the axial member 20. However, FIG. 7 is drawn simulating the case where the axial member 20 is pushed in in the free state before the cylindrical member 18 is inserted into the holes 53 and 63. In reality, each branch portion 80 is not deformed as extremely as depicted in FIG. 7 because it is restricted by the wall surfaces 54 and 64 of the holes 53 and 63. Instead, the outer surface of each branch portion 80 is strongly pressed against and adheres to the wall surfaces 54 and 64. Thereby, similar to the case of FIG. 2 described above, good electrical conductivity between the external terminal member 17 and the terminal portions 51 and 61 can be obtained.

[0038] Even when using the external terminal member 17, the fact that the positive terminal member 5 and the negative terminal member 6 do not protrude outward is the same as in the case of the aforementioned embodiment. Therefore, the point that damage due to external input is less likely to occur is also the same. Although the portion of the axial member 20 that still protrudes upward in the state of FIG. 7 may be deformed, in that case, the axial member 20 may be pulled out upward. Then, the remaining cylindrical member 18 can also be easily pulled out from the holes 53 and 63. After that, a new external terminal member 17 may be reinstalled.

[0039] In the case of the external terminal member 17 in FIG. 5, for what corresponds to the external connection portion 9 in FIG. 3, it may be formed or attached to the upper end portion of the axial member 20. Alternatively, the vicinity of the upper end of the cylindrical member 18 can also be used as the external connection portion 9. In that case, it is desirable that the overall length L2 (see FIG. 6) is longer than the depth D (see FIG. 4) of the bottom surfaces 55 and 65 from the surface of the lid body 31.

[0040] As described in detail above, according to the first and second embodiments, the positive terminal member 5 and the negative terminal member 6 connected to the electrode body 2 inside the battery 1 are provided so as not to protrude from the case 30. By inserting the external terminal members 7 and 17 from the outside into the holes 53 and 63 formed in the positive terminal member 5 and the negative terminal member 6, electrical conduction between the positive terminal member 5, the negative terminal member 6 and the outside is established. Thereby, an in-vehicle battery 1 in which damage due to external input is less likely to occur is realized.

[0041] The present embodiment and examples are merely illustrative and do not limit the disclosed technology in any way. Therefore, the disclosed technology can naturally be variously improved and modified without departing from its gist. For example, there is no particular limitation on the number of branches of the branch portion 80 in the branch section 81. Instead of using the insulating member 36, the insulating portion may be an insulating coating applied to the corresponding portion of the lid body 31. The disclosed technology may be applied to only one of the positive terminal member 5 and the negative terminal member 6.

[0042] In the case of the first embodiment, it is not essential to use a plate-like member as the material of the external terminal member 7. It is also possible to obtain the external terminal member 7 by processing a material having another shape such as a round bar member. In that case, each branch portion 80 of the branching section 81 may be three-dimensionally arranged. When a plate-like member is used as the material of the external terminal member 7, the cross-sectional shapes of the holes 53 and 63 may be rectangular. The same applies to the cross-sectional shape of the through-hole 37 of the insulating member 36.

[0043] In the case of the first embodiment, the width W1 before attachment may be made smaller than the diameter R of the holes 53 and 63, and instead, the neck-down length L1 (see FIG. 3) may be made longer than the depth D in FIG. 4. In this case, even if the lower end of the merging section 83 touches the bottom surfaces 55 and 65, by further continuing to push in until the lower side of the external connection portion 9 hits the insulating member 36, the outer sides of the branch portions 80 can be brought into close contact with the wall surfaces 54 and 64. This is because when pushed in, the branching section 81 is compressed in the length direction, and each branch portion 80 is deformed so as to spread laterally. In that case, it is desirable that the center in the width direction of the branching section 81 is a slit 82.

[0044] It is not essential that the holes 53 and 63 are bottomed holes. When the holes 53 and 63 are through-holes, the airtightness of the internal space of the battery 1 may not be guaranteed depending on the terminal portions 51 and 61. Therefore, instead, the airtightness may be guaranteed at the contact portion between the external connection portion 9 and the insulating member 36. However, it goes without saying that it is more advantageous for airtightness if the holes 53 and 63 are bottomed holes. Also, in the case of the second embodiment, it is better for the holes 53 and 63 to be bottomed holes in order to surely expand the diameter of the branching section 81. The same applies to the case of the first embodiment when the width W1 before attachment is made smaller than the diameter R of the holes 53 and 63.

[0045] [Subordinate Claim 1] An in-vehicle battery according to any one of Claims 1 to 3, The in-vehicle battery in which the hole is a bottomed hole.

Explanation of Reference Numerals

[0046] 1 Battery 20 Axial member 55 Bottom surface 2 Electrode body 21 Hole portion 61 Terminal portion 3 Positive electrode plate 22 Integral section 62 Outer-facing surface 4 Negative electrode plate 30 Case 63 Hole 5 Positive terminal member 31 Cover body 64 Wall surface 6 Negative terminal member 32 Box body 65 Bottom surface 7 External terminal member 36 Insulating member 80 Branch portion 8 Insertion portion 51 Terminal portion 81 Branch section 9 External connection portion 52 Outer-facing surface 83 Confluence section 17 External terminal member 53 Hole 18 Cylindrical member 54 Wall surface

Claims

1. An in-vehicle battery having a case and an electrode body housed in the case and having a positive electrode and a negative electrode, a positive terminal member disposed inside the case and connected to the positive electrode, and a negative terminal member disposed inside the case and connected to the negative electrode, at least one of the positive terminal member and the negative terminal member is provided with an outward-facing surface facing outward, and a hole is formed in the outward-facing surface in a direction toward the inside, an external terminal member is inserted into the hole from the outside, the external terminal member has an insertion portion inserted into the hole, and an external connection portion provided to connect to the outside of the insertion portion, the insertion portion has a branched section branched into a plurality of branch portions, and each of the branch portions is in close contact with the wall surface of the hole. An in-vehicle battery.

2. The in-vehicle battery according to claim 1, having an insulating portion between the outward-facing surface and the external connection portion, and the insulating portion is provided so as to surround a portion between the insertion portion and the external connection portion of the external terminal member. An in-vehicle battery.

3. The in-vehicle battery according to claim 1 or claim 2, wherein the insertion portion has a merging section that does not branch on the tip side from the branched section. An in-vehicle battery.

4. The in-vehicle battery according to claim 1 or claim 2, wherein the insertion portion is a cylindrical member, and a section including an inward-facing end portion is the branched section, A vehicle-mounted battery in which a section outside the branch section is an integral section without branching, and which has an axial member press-fitted from the outside to the integral section. **Claim 5** The vehicle-mounted battery according to claim 4, The vehicle-mounted battery in which the hole is a bottomed hole.

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