JP6679260B2 - Battery pack - Google Patents

Description

  The present invention relates to a battery pack in which a battery that can be charged and discharged is housed in an outer case, and particularly to a battery pack that has excellent durability against a drop impact.

  Along with the widespread use of electric devices such as digital cameras and video cameras, a battery pack having a built-in rechargeable battery has been used as a power source for these electric devices. This battery pack can be conveniently used by repeatedly charging the built-in battery. Further, this battery pack is structured to be detachably set in the electric device main body, and can be detached from the electric device main body for convenient carrying or can be conveniently carried as a spare battery pack. In particular, this type of battery pack is required to have a large capacity so that the electric device can be used for a long time. For this reason, the conventional battery pack has a structure in which a battery block formed by stacking a plurality of batteries in a plurality of stages is housed in a plastic outer case. This battery pack can increase the output voltage by connecting a plurality of batteries in series, and can extend the operating time by connecting a plurality of batteries in parallel.

  As described above, since the battery pack including a plurality of batteries has a large weight, when the battery pack receives a shock such as a drop, the built-in battery may be damaged. In particular, a battery pack that contains a number of batteries in a box-shaped outer case has a battery that is placed in the corner of the outer case because the impact at the time of dropping falls on one point when dropped from the corners of the case. The edges of are most susceptible to damage. For a battery in which the opening of the outer can is closed at the end of the battery with a sealing plate, when a shock is applied to this part, the caulking part of the sealing plate and the outer can deforms, and the sealing state by the sealing plate deteriorates. There is a possibility that harmful effects such as leakage of electrolyte or gas from the inside may occur. In addition, the built-in batteries have lead plates connected by welding, etc. at the electrodes on both end faces, but if the battery ends are subjected to a strong impact, the connection parts between the lead plates and the electrodes will be damaged. However, there is a possibility that adverse effects such as poor contact and short circuit may occur.

  In order to solve these problems, a battery pack has been developed that has a hollow space at the end of the outer case made of plastic and outside the battery housing to absorb the impact when dropped. (Patent Document 1). This structure is characterized in that the impact at the time of dropping the battery pack can be absorbed by the hollow space provided at the end of the outer case to absorb the impact.

  Also, a battery pack has been developed in which a shock absorbing portion made of another member is arranged in a space formed in a corner portion of an outer case (see Patent Document 2). This battery pack is characterized in that a shock absorbing part made of plastic arranged at a corner part absorbs the shock, so that the shock received at the end part of the battery can be alleviated.

  Furthermore, a battery pack has been developed in which a protective member made of a metal plate or a metal wire is arranged at a corner portion of an outer case (see Patent Document 3). In this battery pack, the outer case is mechanically reinforced by the metal protective member arranged at the corner of the outer case, and the corner of the outer case can be protected from an external impact.

JP, 2004-327206, A JP, 2014-164815, A JP, 2011-198472, A

  However, in these battery packs, it is necessary to form a hollow space at the end portion of the outer case or to form a space for arranging a shock absorbing portion and a protective member in order to absorb a shock acting on the outer case. Therefore, there is a problem that the outer shape of the outer case becomes large. Further, in a battery pack that requires separate members such as a shock absorbing portion and a protective member, the number of parts increases and the manufacturing cost increases, and a process for setting these members in place on the outer case is also required. Therefore, there is a problem that manufacturing is troublesome.

  The present invention was developed to solve the above drawbacks. An important object of the present invention is to reduce the shock received by a battery when dropped by a very simple structure without enlarging the outer shape of the battery pack and without disposing a separate member for absorbing the shock. An object of the present invention is to provide a battery pack that can effectively prevent damage to the battery and connection failure.

Means for Solving the Problems and Effects of the Invention

The battery pack of the present invention includes a battery 1 that can be charged and discharged, and an outer case 2 that houses the battery 1. The outer case 2 holds an intermediate portion in the axial direction of the battery 1 that is housed inside. The holding surface 20 is provided on the inner surface of the outer case 2, the battery 1 is held by the holding surface 20, and the corner portion 3 of the outer case facing the peripheral corner portion 13 which is the boundary portion between the end surface 1x and the side surface 1y of the battery 1. The non-contact concave portion 4 is formed inside, and the thickness of the outer case at the corner is smaller than the thickness of the outer case at the holding surface, and the peripheral corner portion 13 is not in contact.

  The battery pack of the present invention has an extremely simple structure and is characterized in that it can reduce the impact of the battery upon being dropped or the like and effectively prevent damage to the battery and connection failure. This battery pack holds the intermediate portion in the axial direction of the battery by the holding surface of the inner surface of the outer case to suppress movement of the battery in the direction intersecting with the holding surface in the outer case, and This is because the non-contact recess formed on the inner surface of the corner facing the peripheral corner that is the boundary portion of the side surface prevents the peripheral corner of the battery from abutting on the inner surface of the corner of the outer case. . In the battery pack of this structure, the peripheral corners of the battery located at the corners of the outer case are held in a non-contact state with the inner surface of the outer case, so that the corners of the outer case may be damaged by a shock such as dropping. Even when a strong force is applied to the battery, this force can be prevented from being directly transmitted from the inner surface of the case to the peripheral corners of the battery. In other words, the void of the non-contact concave portion serves as a cushion to protect the battery from impact force. Therefore, the battery housed in the outer case is effectively prevented from being damaged or having a poor connection because the impact force that acts on the end portion of the battery when dropped is relaxed.

  In particular, since the battery pack of the present invention forms the non-contact concave portion on the inner surface of the outer case, that is, the inner surface of the corner portion facing the peripheral edge corner portion of the battery, the outer shape of the outer case is not increased, and the impact does not occur. It is possible to effectively alleviate the impact at the time of dropping without using a separate member for alleviating the above, while having an extremely simple structure.

  In the battery pack of the present invention, the battery 1 is a cylindrical battery 1A or a rectangular battery in which the opening of the outer can 11 is closed by a sealing plate 12, and the outer case 12 is a peripheral corner of the battery 1 on the sealing plate 12 side. The non-contact concave portion 13 may be provided in the corner portion 3 facing the portion 13.

  This battery pack is provided with a non-contact recess at the corner facing the peripheral edge of the battery on the side of the sealing plate. Can be effectively protected.

  In the battery pack of the present invention, the outer case 2 is composed of a plastic main body case 21 for housing the battery 1 and a plastic lid case 25 for closing the opening of the main body case 21, and the main body case 21 has a rectangular shape. Is a box shape formed by connecting a peripheral wall 23 around a bottom plate 22 of the battery 1, and the peripheral wall 23 is a pair of side surface walls 23Y facing the side surface 1y of the battery 1 and a pair of end surface walls facing the end surface 1x of the battery 1. 23X is connected to form a rectangular cross-section, and the non-contact recess 4 can be formed on the inner surface of the corner 3 of the rectangular peripheral wall 23.

  In this battery pack, the main body case for accommodating the battery is made into a box shape in which a peripheral wall is connected around a rectangular bottom plate, and a non-contact recess is formed on the inner surface of the corner of the rectangular peripheral wall. The battery can be protected by surely making the non-contact concave portion face the peripheral corner portion of the battery housed along it.

  The battery pack of the present invention includes a plurality of batteries 1 and can form a battery block 10 by stacking the plurality of batteries 1 in a mutually parallel posture. The peripheral wall 23 includes a holding surface 20 on the inner surface of the side wall 23Y, and the battery blocks 10 are arranged such that the end faces 1x of the batteries 1 are located on the same plane and are stacked in a plurality of steps on both side faces 1y. The intermediate portion of the battery 1 can be brought into contact with the holding surface 20.

  In this battery pack, a plurality of batteries are stacked in parallel with each other and housed as a battery block in the body case, so that the plurality of batteries can be housed in the body case easily and easily. In addition, the battery block can be housed in the main body case while positioning the plurality of batteries by abutting an intermediate portion of the batteries stacked in a plurality of stages on both sides of the holding surface of the side wall of the main body case.

In the battery pack of the present invention, the battery 1 is a cylindrical battery 1A, and the battery block 10 includes a battery holder 5 in which a plurality of cylindrical batteries 1A are vertically and horizontally arranged and arranged at a fixed position. The cylindrical batteries 1A can be arranged in two rows in the horizontal direction and arranged in multiple stages in the vertical direction.
In this specification, the vertical and horizontal directions are specified in the drawings. That is, the horizontal direction means the horizontal direction in FIG. 4, and the vertical direction means the vertical direction in FIG.

  In this battery pack, a plurality of cylindrical batteries can be easily and accurately arranged vertically and horizontally in a fixed position via a battery holder. In particular, a plurality of cylindrical batteries can be easily housed in an outer case while being arranged in two rows in the horizontal direction and arranged in a plurality of rows in the vertical direction.

  In the battery pack of the present invention, the battery block 10 connects the electrodes on both end surfaces 1x of the plurality of batteries 1 via the lead plate 6, and the end surface 1x of the battery 1 is connected to the peripheral wall 23 via the lead plate 6. It can be held by the inner surface of the end wall 23X.

  With the above configuration, by holding the end surface of the battery on the inner surface of the end surface wall of the peripheral wall via the lead plate, the axial movement of the battery is suppressed by the end surface wall, and by a shock or the like when the battery pack falls. Damage to the end surface of the battery, such as bad contact of the lead plate, can be reduced.

  In the battery pack of the present invention, the non-contact concave portion 4 can be formed in the corner portion 3 of the peripheral wall 23 so as to extend across the side wall 23Y and the end wall 23X and have an L-shape in cross section.

  In this battery pack, since the non-contact concave portion having an L-shaped cross section is formed in the corner portion of the rectangular peripheral wall so as to extend over the side wall and the end surface wall, the side surface side and the end surface side of the peripheral edge corner portion of the battery are formed. It is possible to effectively protect this portion by making both of them in a non-contact state with the peripheral wall.

  In the battery pack of the present invention, the non-contact recess 4 can be formed in a groove shape by extending in the depth direction of the main body case 21 at the corner 3 of the peripheral wall 23.

  In this battery pack, the non-contact recesses formed in the corners of the peripheral wall are formed in a groove shape extending in the depth direction of the main body case, so that the peripheral corners of the battery can be used while using a mold of simple structure. It is possible to surely form the non-contact recess facing the portion.

  Further, in a structure for accommodating a battery block formed by stacking a plurality of batteries in a plurality of stages, the non-contact recess is extended in the depth direction of the main body case to form a groove shape, so that the batteries stacked in a plurality of stages are formed. It is possible to easily and surely form the non-contact concave portion facing the peripheral edge corner portion.

  In the battery pack of the present invention, the non-contact recesses 4 can be formed at the four corners of the rectangular peripheral wall 23.

  Since this battery pack has the non-contact recesses formed at the four corners of the peripheral wall, the peripheral corners of the batteries arranged at the corners of the main body case are not affected by the number, orientation, arrangement, etc. of the batteries stored. Therefore, the non-contact recess can be reliably arranged. In other words, the battery can be stored in the body case without directivity.

  In addition, in a structure in which a battery block formed by stacking a plurality of batteries in a plurality of stages is housed, it is necessary to form a main body case deep in order to house a tall battery block, but in this case, there is a depth. Since the peripheral wall of the main body case becomes high, the peripheral wall on the long side tends to warp inward in the vicinity of the opening as shown by the chain line in FIG. Therefore, in the conventional battery pack, when the battery block is stored in the main body case, it is necessary to insert the battery block while pushing the peripheral wall on the long side curved inward to the outside, which is troublesome. There was such a problem. On the other hand, in the main body case 21 in which the non-contact recesses 4 are formed at the four corners of the peripheral wall 23, the non-contact recesses 4 are formed on both sides of the peripheral wall 3 on the long side, and these parts are thinly formed. Therefore, as shown by the arrow in FIG. 8, the peripheral side wall 23 on the long side curved inward can be easily pushed outward and the battery block can be inserted easily.

  In the battery pack of the present invention, the depth t of the non-contact recess 4 can be set to 0.1 mm to 0.5 mm.

It is a perspective view showing a battery pack concerning one embodiment of the present invention. FIG. 3 is an exploded perspective view of the battery pack of FIG. 1. FIG. 2 is an exploded perspective view of the battery pack of FIG. 1 viewed from below. FIG. 4 is a vertical vertical cross-sectional view of the battery pack of FIG. 1, which is a cross-sectional view taken along line IV-IV of FIG. 1. FIG. 5 is a horizontal sectional view of the battery pack of FIG. 1 and is a sectional view taken along line VV of FIG. 1. FIG. 6 is an enlarged sectional view of a main part of the battery pack of FIG. 5. It is a principal part expanded sectional view which shows another example of a non-contact recessed part. It is a bottom view of the main body case shown in FIG. FIG. 6 is an exploded perspective view of a battery pack according to another embodiment of the present invention, as viewed from below.

  Embodiments of the present invention will be described below with reference to the drawings. However, the embodiment described below exemplifies a battery pack for embodying the technical idea of the present invention, and the present invention does not specify the battery pack to the following. Specifically, the members shown in the claims are not limited to the members of the embodiment. Unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of the constituent members described in the embodiments are not intended to limit the scope of the present invention thereto, but are merely descriptions. It's just an example. The sizes and positional relationships of members shown in the drawings may be exaggerated for clarity of explanation. Further, in the following description, the same names and reference numerals denote the same or similar members, and a detailed description thereof will be omitted as appropriate. Further, each element constituting the present invention may be configured such that a plurality of elements are formed of the same member and one member also serves as the plurality of elements, or conversely, the function of one member may be performed by a plurality of members. It can be realized by sharing. Also, the contents described in some of the examples and embodiments may be applicable to other examples and embodiments.

(Embodiment 1)
1 to 6 show a battery pack according to an embodiment of the present invention, which is used by being set in electric equipment such as a video camera or a digital camera and which supplies driving power to these electric equipment. Show. However, it goes without saying that the battery pack of the present invention is not limited to the use application thereof to electric equipment such as video cameras and digital cameras, and can be appropriately used for other electric equipment such as electric tools. Absent.

  1 to 6, FIG. 1 is a perspective view showing a battery pack, FIG. 2 is an exploded perspective view of the battery pack of FIG. 1, FIG. 3 is an exploded perspective view of the battery pack of FIG. 1 seen from below, and FIG. 1 is a vertical longitudinal sectional view of the battery pack of FIG. 1, FIG. 5 is a horizontal sectional view of the battery pack of FIG. 1, and FIG. 6 is an enlarged sectional view of a main part of the battery pack of FIG. The battery pack 100 shown in FIGS. 1 to 6 includes a battery 1 that can be charged and discharged and an outer case 2 that houses the battery 1.

(Battery 1)
The battery 1 is a secondary battery that can be charged and discharged. A lithium ion secondary battery is used as the battery 1 which is a secondary battery. The lithium-ion secondary battery has a high electric capacity per volume, is suitable for miniaturization, and is preferable as a portable battery pack. However, the battery is not limited to the lithium ion secondary battery, but may be a rechargeable battery such as a nickel hydrogen battery or a nickel cadmium battery.

  In the battery 1, the opening of the bottomed outer can 11 is closed by the sealing plates 12, and the end surfaces 1x at both ends in the axial direction are positive and negative electrodes. As shown in FIG. 5, the battery 1 has an end surface 1x, which is the bottom surface of the outer can 11, and an end surface 1x, which is the central portion of the sealing plate 12 that closes the outer can 11, as positive and negative electrodes. In the battery 1, the outer can 11 and the sealing plate 12 are made of metal, and the opening of the outer can 11 is closed by the sealing plate 12 in a state of insulating them. The battery 1 is insulated around the outer can 11 in order to prevent the lead plates 5 connected to the electrodes on both ends from unintentionally contacting the outer can 11 and the sealing plate 12 of another battery 1. It is covered with a tube (not shown).

  The battery pack 100 in FIGS. 2 to 4 includes a plurality of batteries 1, and these batteries 1 are stacked in a plurality of stages and housed in the outer case 2 as a battery block 10. The plurality of batteries 1 are arranged in parallel with each other and stacked in a plurality of stages. In the battery pack 100 shown in the figure, the battery 1 is a cylindrical battery 1A, and a plurality of cylindrical batteries 1A are vertically and horizontally arranged and stacked to form a generally rectangular parallelepiped shape.

  The battery pack of the present invention is characterized in that, when a strong impact force is exerted from the outside due to a drop or the like, the impact that acts on the battery housed in the outer case is mitigated to protect the housed battery. In particular, the present invention mitigates the shock received by the battery pack due to dropping or the like, without enlarging the outer shape of the outer case that houses the battery and without using a separate member for mitigating the shock. In order to realize this, in the present invention, the outer case that houses the battery has a unique structure. Therefore, for the battery pack of the present invention, as for the battery housed in the outer case and the battery block configured by assembling a plurality of batteries, all the batteries that have already been used or will be used in the future should be adopted. You can Hereinafter, the structure of the outer case will be described in detail.

(Exterior case 2)
As shown in FIGS. 1 to 6, the outer case 2 is formed into a rectangular parallelepiped box shape. The outer case 2 has a storage space formed therein, and the storage space has a size capable of storing the battery block 10 including the plurality of batteries 1. The outer case 2 has, on the inner surface of the outer case 2, a holding surface 20 that holds an intermediate portion in the axial direction of the battery 1 housed inside. The outer case 2 shown in FIGS. 4 and 5 holds the battery 1 by bringing the side surface 1y of the battery 1 into contact with the holding surface 20. The holding surface 20 shown in FIG. 4 is held in contact with the axially intermediate portion of the battery 1 except for both end portions. Here, the intermediate part of the battery 1 is an intermediate part excluding both ends of the battery 1, and when the total length (L) of the battery 1 is 1, 2 to 20%, preferably 3 to 10% of both ends. It means the part excluding the area.

  In this specification, "the holding surface of the outer case holds the middle portion of the battery" does not necessarily mean that the holding surface of the outer case is always in contact with the side surface of the battery to hold the battery. For example, even if there is a slight gap between the holding surface of the outer case and the side surface of the battery, the holding surface suppresses the movement of the battery housed in the outer case and substantially holds the battery. Used in a broad sense, including state. That is, the holding surface of the outer case does not have to be held in a state where the intermediate portion of the battery is always in contact, and even if there is some clearance, it does not contact the intermediate portion of the battery when it receives a shock such as dropping. It is used in a broad sense, including the state of holding a battery in contact with it. However, the outer case can hold the battery more reliably by bringing the holding surface into contact with the side surface of the battery. Therefore, the outer case preferably holds the battery with the holding surface being in contact with the side surface of the battery.

  Further, the outer case 2 is a boundary portion between the end surface 1x and the side surface 1y of the battery 1 in order to prevent an impact force applied to a corner portion of the outer case 2 from directly acting on the end portion of the battery 1 due to dropping or the like. On the inner surface of the corner portion 3 facing the peripheral edge corner portion 13, a non-contact concave portion 4 that does not contact the peripheral edge corner portion 13 is formed. The outer case 2 holds the middle portion of the battery 1 by the holding surface 20 of the outer case 2 to suppress movement of the battery 1 in a direction intersecting with the holding surface 20, while the peripheral corner portion 13 of the battery 1 is held. By forming the non-contact concave portion 4 in the corner portion 3 facing the corner portion 3, the peripheral edge corner portion 13 of the battery 1 is prevented from coming into contact with the inner surface of the corner portion 3 of the outer case 2. Therefore, even when the corner portion 3 of the outer case 2 receives a strong force from the outside, this force is prevented from being directly transmitted from the inner surface of the outer case 2 to the peripheral corner portion 13 of the battery 1 and the end of the battery 1 is prevented. Can protect the department.

  The outer case 2 can preferably be provided with a non-contact concave portion 4 at a corner 3 facing the peripheral corner 13 on the side of the sealing plate 12 of the battery 1. In the battery 1 in which the opening of the outer can 11 is closed by the sealing plate 12, if a strong impact force is applied to this portion, the sealed state of the sealing plate 12 may be deteriorated and the electrolyte or gas may leak from the inside. Therefore, by providing the non-contact concave portion 4 in the corner portion 3 of the battery 1 facing the peripheral corner portion 13 on the sealing plate 12 side, the end portion on the sealing plate 12 side where the battery 1 is easily damaged is effectively protected. it can. However, in the outer case 2, the non-contact concave portion 4 can be provided in the corner portion 3 facing the peripheral corner portion 13 on the can bottom side of the outer can 11. This structure can protect both ends of the battery 1 from impact.

  The exterior case 2 shown in FIGS. 1 to 6 is composed of a main body case 21 that is formed into a box shape for housing the battery 1 and has one opening, and a lid case 25 that closes the opening of the main body case 21. . The main body case 21 and the lid case 25 can be made of plastic having excellent insulating properties, for example, polycarbonate.

(Main body case 21)
The main body case 21 has a box shape formed by connecting a peripheral wall 23 around a rectangular bottom plate 22, and has an inner shape capable of housing the battery block 10. The rectangular bottom plate 22 has a shape and size along the upper surface 10C of the substantially rectangular battery block 10. The peripheral wall 23 connects the pair of side surface walls 23Y facing the side surface 1y of the battery 1 and the pair of end surface walls 23X facing the end surface 1x of the battery 1 and has a rectangular cross section. The peripheral wall 23 is provided with a holding surface 20 for holding the intermediate portion of the battery 1 on the inner surface of the side wall 23Y. The main body case 21 holds the battery 1 in a state where the battery block 10 is housed therein, and the side surface 1y of the battery 1 which is both side surfaces 10A of the battery block 10 is brought into contact with the holding surface 20 of the side wall 23Y. .

  Further, the main body case 21 holds both end surfaces 10B of the battery block 10 by the inner surface of the end surface wall 23X of the peripheral wall 23 in a state where the battery block 10 is housed inside. In the battery block 10 shown in FIGS. 2 and 3, the electrodes on both end surfaces 1x of the plurality of batteries 1 are connected via the lead plate 6, and the end surface 1x of the battery 1 is connected to the end surface wall 23X via the lead plate 6. It is held inside. The main body case 21 shown in FIG. 5 holds the battery 1 in a state where both end surfaces 10B of the battery block 10 are in contact with the inner surface of the end surface wall 23X. However, the main body case 21 is not necessarily limited to a state in which the inner surface of the end surface wall is always brought into contact with and held by the end surface 10B of the battery block 10. As described above, even if there is a slight gap between the inner surface of the end wall 23X and the end surface 10B of the battery block 10, the end wall 23X suppresses the movement of the battery 1 housed in the main body case 21. Therefore, the battery 1 can be substantially held.

(Non-contact recess 4)
Further, the main body case 21 has a non-contact recess 4 formed on the inner surface of the corner 3 of the rectangular peripheral wall 23, that is, the inner surface of the boundary portion between the side wall 23Y and the end wall 23X. The non-contact recessed portion 4 shown in FIGS. 5 and 6 is formed in an L shape in cross section in the corner portion 3 of the peripheral wall 23, straddling the side wall 23Y and the end wall 23X. The non-contact concave portion 4 having an L-shaped cross section is composed of an end surface portion 4X formed on the end surface wall 23X and a side surface portion 4Y formed on the side surface wall 23Y. The non-contact concave portion 4 of this shape has the end surface portion 4X on the end surface side of the peripheral corner portion 13 and the side surface portion 4Y on the side surface side so that the peripheral corner portion 13 of the battery 1 does not contact the inner surface of the corner portion 3. It is placed in contact. With this structure, both the end surface side and the side surface side of the peripheral corner portion 13 of the battery 1 are brought into non-contact with the peripheral wall 23, and this portion can be effectively protected.

  In the non-contact concave portion 4 having an L-shaped cross-section, the width (h1) of the end face portion 4X and the width (h2) of the side surface portion 4Y are optimal widths, and the depth (t) of the non-contact concave portion 4 is optimal. It is formed to have a depth. The width (h1) of the end face portion 4X can be set to 3 to 15%, preferably 5 to 12% with respect to the width (H1) of the end face wall 23X. It is preferable that the width (h1) of the end face portion 4X be such that the inner surface of the end face wall 23X can be arranged to face the lead plate 6 connected to the end face 1x of the battery 1. Further, the width (h2) of the side surface portion 4Y can be set to 2 to 15%, preferably 3 to 10% with respect to the width (H2) of the side surface wall 23Y. It is preferable that the width (h2) of the side surface portion 4Y be a width that can cover the area where the sealing plate 12 and the caulking portion 14 that holds the sealing plate 12 in place are arranged, particularly on the sealing plate 12 side of the battery 1. .

  Further, the depth (t) of the non-contact concave portion 3 can be set to 0.1 mm to 0.5 mm, preferably 0.2 to 0.4 mm. However, the depth (t) of the non-contact concave portion 3 can be specified with respect to the wall thickness (d) of the peripheral wall. For example, in the main body case 21, the wall thickness (d) of the peripheral wall 23 can be set to 1 mm to 3 mm, preferably 1.5 to 2 mm, and the depth (t) of the non-contact recessed portion 3 can be set within the above range. When the wall thickness (d) of the peripheral wall 23 of the main body case 21 is increased, the strength of the case is increased, but the overall weight is increased and the cost is increased. Further, when the depth (t) of the non-contact concave portion 4 is increased, it is possible to effectively prevent the peripheral corner portion 13 from coming into contact with the inner surface of the peripheral wall 23, but the strength of the case itself is reduced. Therefore, in consideration of the above, the body case 21 determines the wall thickness (d) of the peripheral wall 23 and the depth (t) of the non-contact recess 4 to be optimum.

  In the non-contact concave portion 4 shown in the enlarged cross-sectional view of FIG. 6, the tip of the end face portion 4X is a stepped portion 4a and the tip of the side face portion 4Y is a tapered surface 4b. The taper surface 4b shown in the figure has a shape that gradually becomes deeper from the protective surface 20 of the side wall 23Y toward the corner 3. However, in the non-contact concave portion 4, as shown in FIG. 7, both ends of the end surface portion 4X and the side surface portion 4Y may be stepped portions 4a, or although not shown, a tapered surface may be provided at the end portion of the end surface portion. it can.

  Further, the non-contact recess 4 shown in FIG. 3 is formed in a groove shape extending in the depth direction of the main body case 21. Since the non-contact concave portion 4 is formed in a groove shape extending in the depth direction, the non-contact concave portion 4 can be reliably arranged at a position facing the peripheral corner portion 13 of the battery 1 while using a mold having a simple structure. In particular, in the state where the battery block 10 is housed, the non-contact concave portion 4 facing the peripheral corner portions 13 of the plurality of batteries 1 stacked in a plurality of stages can be formed easily and reliably.

  In the main body case 21 shown in FIG. 5, the non-contact recesses 4 are formed at the four corners of the rectangular peripheral wall 23. The main body case 21 surely contacts the peripheral corner portion 13 of the battery 1 arranged in the corner portion 3 of the peripheral wall 23 without being influenced by the number, direction, arrangement, etc. of the batteries to be accommodated. Can be placed.

  Further, the main body case 21 for accommodating the battery block 10 formed by stacking the plurality of batteries 1 in a plurality of stages is formed deeply for accommodating the tall battery block 10, but the main body case 21 with the depth is Since the peripheral wall 23 becomes high, the side wall 23Y, which is the peripheral wall 23 on the long side, tends to warp inward in the vicinity of the opening as shown by the chain line in FIG. Therefore, in the conventional battery pack, when the battery block is stored in the main body case, it is necessary to insert the battery block while pushing the peripheral wall on the long side curved inward to the outside, which is troublesome. There was such a problem.

  On the other hand, in the battery pack of the present invention, since the non-contact recess 4 is formed in the corner 3 of the peripheral wall 23, the non-contact recess 4 is intentionally formed so that the peripheral wall on the long side is outward. It can be spread easily. For example, in the main body case 21, by forming the non-contact recesses 4 extending in the depth direction in the corners 3 located on both sides of the side wall 23Y which is the long side, both side edges of the side wall 23Y are thinned. It can be molded, and the side wall 23Y can be easily expanded to the outside. Therefore, the battery block 10 can be easily inserted into the main body case 21. Further, as shown in FIG. 8, the main body case 21 in which the non-contact recesses 4 are formed at the four corners of the rectangular peripheral wall 23 has the side walls 23Y facing each other deformed to the outside as shown by the arrows in the figure. The battery block 10 can be inserted easily. Therefore, in this battery pack, the work efficiency can be improved by simply and easily inserting the battery block 10 into the main body case 21 having a depth.

(Lid case 25)
The lid case 25 has a shape along the opening edge of the main body case 21, and is formed in a shallow box shape in which a low peripheral wall 27 is provided around a rectangular bottom plate 26. The lid case 25 has such a depth that the circuit board 7 arranged on the bottom surface 10D of the battery block 10 can be housed, but has a height such that the side surface 1y of the cylindrical battery 1A arranged at the bottom is not in contact. In the main body case 21, the circuit board 7 is arranged on the bottom surface side of the battery block 10 located in the opening with the battery block 10 housed inside. The lid case 25 is connected to the main body case 21 while guiding a part of the battery 1 located at the lowermost stage of the battery block 10 and the circuit board 7 arranged on the bottom surface 10D of the battery block 10 to the main body case 21. The opening of the case 21 is closed.

  In the lid case 25, a peripheral wall 27 is provided around a bottom plate 26 that covers the circuit board 7, and a leading edge of the peripheral wall 27 is connected and fixed to an opening edge of the main body case 21. The lid case 25 has a terminal window 34 opened to expose the connection terminal 33 fixed to the circuit board 7 to the outside. The lid case 25 shown in FIG. 3 has a slit-shaped notch at one end to open the terminal window 34. The lid case 25 exposes the connection terminal 33 fixed to the built-in circuit board 7 to the outside through the terminal window 34 in a state where the opening of the body case 21 is closed.

  The main body case 21 and the lid case 25 are fixed by ultrasonically welding the peripheral walls 23 and 27 to each other, and the battery block 10 and the circuit board 7 are incorporated therein. The main body case 21 and the lid case 25 shown in FIGS. 2 to 4 are provided with a locking claw 30 and a locking part 31 at a connecting portion for ultrasonic welding in order to ultrasonically weld the facing peripheral walls 23 and 27 without displacement. Is provided. The main body case 21 is provided with welding ribs 24 extending downward along the lower edge of the peripheral wall 23. The welding rib 24 is provided inside the tip end portion so as to project the plurality of locking claws 30. The lid case 25 is provided with a connecting piece 28 that guides the engaging claw 30 inside the tip of the peripheral wall 27, and forms a locking portion 31 that locks the engaging claw 30 on the connecting piece 28. The exterior case 2 having this structure is ultrasonically welded by ultrasonically vibrating the connecting portion between the main body case 21 and the lid case 25 while guiding the locking claw 30 to the locking portion 31. However, the main body case and the lid case can be fixed by adhesion or connected by a locking structure.

(Mounting guide 35)
Further, the outer case 2 is provided with a mounting guide 35 so that when the battery pack is connected to an electric device, it can be attached to and detached from a mounting portion of the electric device while sliding in a correct posture. The outer case 2 shown in FIGS. 1 to 4 is provided with a plurality of mounting projections 35A that are guided by mounting recesses (not shown) provided in a mounting portion of an electric device so as to project from both side surfaces of the lid case 25. There is. The mounting convex portion 35A is guided to a mounting recess (not shown) provided in the mounting portion of the electric device, and the battery pack is set at a fixed position of the electric device. Further, the connection terminal 33 exposed from the terminal window 34 is electrically connected to a device-side connection terminal (not shown) of the electric device in a state where the battery pack is set at a fixed position of the electric device.

(Battery block 10)
The battery pack 100 illustrated in FIGS. 2 to 4 includes eight cylindrical batteries 1A, and the eight cylindrical batteries 1A are stacked in two rows and four stages to form a battery block 10 having a substantially rectangular parallelepiped outer shape. I am trying. The number of batteries constituting the battery block is not limited to eight, but may be seven or less, or nine or more. Here, the even number of cylindrical batteries 1A can be arranged in two rows and stacked in a plurality of stages. For example, like a battery pack 200 shown in FIG. 9, four cylindrical batteries 1A can be stacked and arranged in two rows and two stages. Alternatively, although not shown, the six cylindrical batteries 1A may be stacked and arranged in two rows and three stages. It should be noted that the present invention does not specify the battery to be housed as a cylindrical battery. A prismatic battery can also be used as the battery. A plurality of prismatic batteries can be stacked in the thickness direction to form a battery block.

(Battery holder 5)
The battery block 10 includes a battery holder 5 that arranges a plurality of batteries 1 vertically and horizontally in a fixed position. The battery holder 5 is molded of plastic so that the cylindrical batteries 1A can be arranged in a fixed position while being insulated. The battery holder 5 is provided between the batteries 1 adjacent to each other, and includes an insulating wall 50 that insulates the adjacent batteries 1 from each other. In the battery block 10 shown in FIG. 4, eight cylindrical batteries 1A are arranged side by side in two rows and four columns. Therefore, the insulating wall 50 of the battery holder 5 includes a vertical insulating portion 51 arranged between the batteries 1 located on the left and right sides and a horizontal insulating portion 52 arranged between the batteries 1 located on the upper and lower sides. .

  The vertical insulating portion 51 includes a curved plate portion 51A having a curved surface along one side of the cylindrical battery 1A facing the curved surface, and a plurality of vertical insulating portions 51 arranged in a posture intersecting with the cylindrical battery 1A facing the opposite side surface. And a rib 51B. The plurality of vertical ribs 51B are arranged apart from each other in the axial direction of the battery 1 and have curved concave portions having a shape along the corresponding curved surface of the cylindrical battery 1A. The vertical insulating portion 51 arranges one of the left and right batteries 1 along a curved surface on one side of the curved plate portion 51A, and arranges the other battery 1 along a curved concave portion of the vertical rib 51B at a fixed position. It has a structure that allows it. The battery holder 5 shown in the figure has a shape in which the vertical insulating portions 51 located between the horizontal insulating portions 52 and arranged vertically are alternately reversed, and the batteries 1 arranged on the left and right are arranged at fixed positions. There is.

  The lateral insulating portion 52 has a flat plate shape, and its tip has a length that does not project from the side surface 1y of the battery 1 located on the outermost side. Further, the lateral insulating portion 52 is provided with a Y-shaped holding portion 53 along the curved surface of the battery 1 at a position which is a tip portion thereof and faces both ends of the battery 1. The Y-shaped holding portion 53 has curved portions along the curved surfaces of the battery 1 formed on both upper and lower surfaces thereof, and one curved portion is brought into contact with the upper surface of the battery 1 arranged in the lower stage to position the curved portion. The other curved portion is brought into contact with the upper surface of the battery 1 arranged in the upper stage for positioning.

  Further, the battery holder 5 is provided with a bottom surface insulating portion 54 that holds the lower surface of the battery 1 arranged at the lowermost stage while positioning it. The bottom surface insulating portion 54 has a curved portion formed on the upper surface, and holds the lower surface of the battery 1 arranged at the lowermost stage in a fixed position while positioning it.

  Further, as shown in FIGS. 4 to 7, the battery block 2 has a plurality of batteries 1 arranged vertically and horizontally via a battery holder 5 arranged in a predetermined arrangement via lead plates 6 connected to both end faces 1x. It is electrically connected with. The battery blocks 2 of FIGS. 2 and 3 are formed by stacking two vertically adjacent batteries 1 in the same direction and stacking them, and connecting opposing electrodes of these batteries 1 with a lead plate 6 so that they are parallel to each other. Connected to. Further, the connecting bodies of the batteries 1 connected in parallel with each other are connected in series with each other, and the eight batteries 1 are connected in a 4 × 2 manner. However, the present invention does not specify the number of batteries constituting the battery block and the connection state thereof. For example, in the battery pack 200 shown in FIG. 9, four batteries 1 are connected in series.

(Lead plate 6)
The lead plate 6 is a flat metal plate having excellent conductivity and is connected to the end surface 1x of the battery 1. The lead plates 6 shown in FIGS. 2 and 3 are arranged at both ends of a plurality of batteries 1 connected in series, and output lead plates 6A from which the output of the battery block 10 is taken out, and four batteries 1 are connected in parallel. And an intermediate lead plate 6B connected in series. The intermediate lead plate 6B extends a detection lead portion 6a for taking out an intermediate potential to the circuit board 7. The lead plate 6 shown in the figure is connected to the electrode of the battery 1 by spot welding, and the output lead plate 6A and the detection lead portion 6a are extended to the circuit board 7 and connected to the circuit board 7.

(Circuit board 7)
The circuit board 7 is an insulating substrate, and is arranged to face the bottom surface 10D of the battery block 2 as shown in FIG. The circuit board 7 is connected to the lead plate 6 drawn out from the battery block 10. Furthermore, the circuit board 7 is mounted with electronic components that realize a protection circuit for the battery 1. The protection circuit controls the charging / discharging current so that the voltage, the remaining capacity, and the temperature of the battery 1 fall within preset ranges. Further, the circuit board 7 includes a remaining capacity detection circuit (not shown) that detects the remaining capacity of the battery 1. The remaining capacity detection circuit calculates the remaining capacity from the voltage and current of the battery 1 and displays the remaining capacity of the battery pack on the display unit 16.

(Sub circuit board 15, display unit 16)
In the battery pack 100 shown in FIGS. 2 and 4, the sub circuit board 15 that realizes the display unit 16 is arranged on the upper surface of the battery block 10. As the display unit 16, the sub-circuit board 15 has a plurality of LEDs 16A for displaying the remaining capacity of the battery 1 mounted on the upper surface. The sub-circuit board 5 shown in FIG. 2 has a plurality of LEDs 16A arranged facing a plurality of display windows 36 provided on the bottom plate 22 of the main body case 21. The sub-circuit board 15 shown in FIG. 2 is mounted with four LEDs, and the lighting state is controlled to display the remaining capacity of the battery 1. The sub circuit board 15 is connected to the circuit board 7 via a bendable harness 18.

(Operation switch 17)
Further, the sub circuit board 15 shown in FIG. 2 is also mounted with an operation switch 17. The operation switch 17 is a switch for causing the display unit 16 to display the state of the battery 1. The display unit 16 is normally in the OFF state, and when the operation switch 17 is pressed, the display is executed for a certain period of time, and after the lapse of the certain period of time, the display is returned to the OFF state. An operation button 37 is arranged on the outer surface of the bottom plate 22 of the main body case 21, which is the surface of the outer case 2. The operation button 37 is arranged adjacent to the display window of the LED 16A. The operation button 37 is coupled to the operation switch 17 mounted on the sub circuit board 15 so as to press the operation switch 17.

(Connection terminal 33)
Further, the battery pack 100 includes a plurality of connection terminals 33 as an electric connection portion for electrically connecting to an externally connected electric device. The connection terminal 33 is fixed to the circuit board 7. The plurality of connection terminals 33 are positive and negative output terminals 33A connected to the output side of the battery 1 built in the battery pack 100, and a signal terminal 33B for outputting information of the protection circuit, for example, battery temperature and battery information. Consists of. As shown in FIG. 3, the connection terminal 33 is exposed to the outside through a terminal window 34 opened in the lid case 25 of the outer case 2. Although not shown, the connection terminal 33 is electrically connected to a device-side connection terminal provided on the mounting portion of the electric device.

(Cushion material 19)
Further, in the battery block 10 shown in FIGS. 2 and 4, the cushion member 19 is fixed to the upper surface 10C of the body case 21 that faces the bottom plate 22. The cushion material 19 is urethane resin or silicone resin having excellent cushioning properties. The battery block 10 shown in the figure has two rows of cushion members 19 arranged on the upper surface 10C. The cushion material 19 has a strip shape extending in the axial direction of the battery 1, and is fixed to each of the batteries 1 arranged on the left and right. The cushion material 19 absorbs the clearance between the upper surface 10C of the battery block 10 and the bottom plate 22 of the main body case 21 to hold the battery block 10 in a fixed position of the main body case 21, and also absorbs shocks and vibrations from the outside. The battery block 10 can be protected.

  Although not shown, the battery pack 100 described above is connected to an electric device such as a digital camera or a video camera, and supplies power to the electric device from the built-in battery 1. In addition, the battery pack 100 is charged with the built-in battery 1 by electric power supplied through an electric device to which a charging adapter is connected, or by electric power placed on a charging stand and supplied from the charging stand. .

  The battery pack according to the present invention is set in an electric device such as a video camera or a digital camera, and is preferably used as a portable battery pack that supplies electric power to these electric devices.

100, 200 ... Battery pack 1 ... Battery 1A ... Cylindrical battery 1x ... End surface 1y ... Side surface 2 ... Exterior case 3 ... Corner 4 ... Non-contact recess 4X ... End surface portion 4Y ... Side surface portion 4a ... Step portion 4b ... Tapered surface 5 ... Battery holder 6 ... Lead plate 6A ... Output lead plate 6B ... Intermediate lead plate 6a ... Detection lead section 7 ... Circuit board 10 ... Battery block 10A ... Side surface 10B ... End surface 10C ... Top surface 10D ... Bottom surface 11 ... External can 12 ... Sealing plate 13 ... Peripheral corner part 14 ... Crimping part 15 ... Sub circuit board 16 ... Display part 16A ... LED
17 ... Operation switch 18 ... Harness 19 ... Cushion material 20 ... Retaining surface 21 ... Main body case 22 ... Bottom plate 23 ... Perimeter wall 23X ... End wall 23Y ... Side wall 24 ... Welding rib 25 ... Lid case 26 ... Bottom plate 27 ... Perimeter wall 28 ... Connection piece 30 ... Locking claw 31 ... Locking portion 33 ... Connection terminal 33A ... Output terminal 33B ... Signal terminal 34 ... Terminal window 35 ... Mounting guide 35A ... Mounting convex portion 36 ... Display window 37 ... Operation button 50 ... Insulating wall 51 ... Vertical insulating portion 51A ... Curved plate portion 51B ... Vertical rib 52 ... Horizontal insulating portion 53 ... Y-shaped holding portion 54 ... Bottom insulating portion

Claims (10)

A battery pack comprising a chargeable / dischargeable battery and an outer case containing the battery,
The outer case has a holding surface on an inner surface of the outer case for holding an intermediate portion in the axial direction of the battery housed therein, the holding surface holds the battery, and an end surface and a side surface of the battery. Is formed inside the corner of the outer case facing the peripheral corner that is the boundary part of the outer case , and the thickness of the outer case at the corner is thinner than the thickness of the outer case at the holding surface, A battery pack in which a non-contact recess is formed so that the parts do not abut. The battery pack according to claim 1, wherein
The battery is a cylindrical battery or a prismatic battery in which an opening of an outer can is closed by a sealing plate, and the outer case is in non-contact with a corner of the battery facing the peripheral corner of the sealing plate. A battery pack having a recess. The battery pack according to claim 1 or 2, wherein
The exterior case includes a plastic main body case for accommodating the battery, and a plastic lid case for closing the opening of the main body case,
The main body case has a box shape formed by connecting peripheral walls around a rectangular bottom plate, and the peripheral walls include a pair of side wall surfaces facing side surfaces of the battery and a pair of side wall surfaces facing end surfaces of the battery. By connecting the end face wall, the cross-sectional shape is square,
A battery pack in which the non-contact recess is formed on the inner surface of a corner of the rectangular peripheral wall. The battery pack according to claim 3, wherein
A plurality of the batteries are provided, and the plurality of batteries are stacked in parallel with each other to form a battery block,
The peripheral wall includes the holding surface on the inner surface of the side wall,
The battery block is a battery pack in which the end surfaces of the batteries are arranged on the same plane, and the intermediate portions of the batteries stacked in a plurality of stages are in contact with the holding surface on both side surfaces. The battery pack according to claim 4, wherein
The battery is a cylindrical battery, the battery block is provided with a battery holder for arranging the plurality of cylindrical batteries vertically and horizontally in a fixed position,
A battery pack in which the battery holder has the plurality of cylindrical batteries arranged in two rows in a horizontal direction and arranged in a plurality of rows in a vertical direction. The battery pack according to claim 4 or 5, wherein
The battery block is a battery pack in which electrodes on both end surfaces of the plurality of batteries are connected via lead plates, and the end surfaces of the batteries are held on the inner surfaces of the end wall of the peripheral wall via the lead plates. . The battery pack according to any one of claims 3 to 6,
A battery pack in which the non-contact concave portion is formed in an L shape in a cross section in the corner portion of the peripheral wall, straddling the side wall and the end wall. The battery pack according to any one of claims 3 to 7, wherein
The battery pack, wherein the non-contact recess is formed in a groove shape extending in the depth direction of the main body case at a corner of the peripheral wall. The battery pack according to any one of claims 3 to 8, wherein:
A battery pack in which the non-contact recesses are formed at four corners of the rectangular peripheral wall. The battery pack according to any one of claims 1 to 9,
A battery pack in which the depth of the non-contact recess is 0.1 mm to 0.5 mm.

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