JP7681998B2 - Battery pack - Google Patents

Description

The present invention relates to a battery pack in which the connection terminals are exposed through a terminal window in the case.

Battery packs with connection terminals in the terminal windows of the case are often used in portable devices such as cameras, but these battery packs can be conveniently used by setting them in a predetermined position in an external device such as a portable device, and electrically connecting the multiple connection terminals to the terminals of the device. When set in a fixed position in the case, the battery pack is required to have the characteristic of being able to reliably and stably electrically connect the connection terminals to multiple terminals such as the power terminals and signal terminals of the external device for a long period of time without causing poor contact. To achieve this, conventional battery packs have multiple connection terminals fixed to a terminal holder, and this terminal holder is built into the case. In order to position the multiple connection terminals in a fixed position, the terminal holder is connected to a circuit board or a battery holder, and is positioned in a fixed position in the case via the holder. (See Patent Document 1)

JP 2014-138483 A

Battery packs in which multiple connection terminals are fixed to a terminal holder, the terminal holder is connected to a circuit board or battery holder, and each connection terminal is placed inside a case have the disadvantage that it is difficult to position all of the connection terminals in the correct positions, and the structure and number of parts are large, resulting in high parts costs and manufacturing costs.

The present invention was developed with the aim of eliminating the above-mentioned shortcomings of conventional battery packs, and an important objective of the present invention is to provide a battery pack with a simple structure that allows multiple connection terminals to be positioned accurately in the case while reducing component and manufacturing costs.

A battery pack according to one embodiment of the present invention comprises a battery unit in which battery cells are arranged in fixed positions by cell holders, a circuit board arranged in fixed positions in the battery unit, and a case housing the circuit board and the battery unit. The circuit board has a plurality of connection terminals fixed to its surface for connection to external devices. The case has a surface plate with a terminal window opening that exposes the connection terminals to the outside. The circuit board is connected to the cell holder in a fixed position, and is sandwiched between the battery unit and the surface plate with a terminal window opening, and is arranged in a fixed position within the case, exposing the connection terminals to the terminal window.

The above battery pack has a simple structure that reduces component and manufacturing costs while allowing multiple connection terminals to be positioned precisely on the case.

1 is a perspective view of a battery pack according to an embodiment of the present invention; FIG. 2 is an exploded perspective view of the battery pack shown in FIG. 1 . 3 is an exploded perspective view of the battery pack shown in FIG. 2 as viewed from below. 4 is a cross-sectional view of the battery pack shown in FIG. 1 taken along line IV-IV. FIG. 4 is a cross-sectional view showing a state in which the battery unit is being inserted into the box-shaped case. FIG. 4 is a cross-sectional view showing a state in which the battery unit is being inserted into the box-shaped case. FIG. 11 is an enlarged sectional perspective view showing a locked state between a first case locking portion and a first holder locking portion; FIG. 13 is an enlarged cross-sectional perspective view showing a locked state between a second case locking portion and a second holder locking portion. FIG.

A battery pack according to one embodiment of the present invention comprises a battery unit in which battery cells are arranged in fixed positions by cell holders, a circuit board arranged in fixed positions in the battery unit, and a case housing the circuit board and the battery unit, the circuit board having a number of connection terminals fixed to its surface for connection to external devices, the case having a surface plate with a terminal window that exposes the connection terminals to the outside, the circuit board being connected to the cell holder in a fixed position and sandwiched between the battery unit and the surface plate with the terminal window, and arranged in a fixed position within the case, with the connection terminals exposed in the terminal window.

In the above battery pack, a circuit board is placed in a fixed position on a cell holder that holds battery cells in fixed positions, and multiple connection terminals are fixed directly to this circuit board, eliminating the need for a terminal holder to fix multiple connection terminals as in conventional battery packs. In addition, because multiple connection terminals are fixed directly to the circuit board, wiring such as lead wires connecting the connection terminals to the circuit board can also be omitted. By omitting the terminal holder, component costs can be reduced, and there is no need to connect the terminal holder to the circuit board or battery holder, simplifying the manufacturing process and reducing manufacturing costs.

Furthermore, battery packs require protection circuits to control the charging and discharging of battery cells, and therefore require a circuit board to mount this protection circuit. However, as this circuit board mounts various electronic components, it has a larger external shape than a terminal holder that only has connection terminals, and since it is placed in a fixed position within the case via a cell holder, the connection terminals that are fixed directly to the circuit board are placed in a fixed position within the case by the circuit board.

Furthermore, in the above battery pack, the circuit board is sandwiched and positioned in a fixed position between the battery unit, in which the battery cells are placed in a fixed position by the cell holder, and the surface plate of the case, which has an opening for a terminal window, so that the circuit board with the connection terminals can be brought closest to the inner surface of the surface plate with the terminal window. The circuit board is brought closest to the inner surface of the surface plate with the terminal window, and the connection terminals fixed to the circuit board are brought closest to the inner surface of the surface plate and placed in an optimal position for the terminal window. This structure prevents the connection terminals from shifting relative to the terminal window of the surface plate and the connection terminals, and holds them in a fixed position on the case with high precision, and in particular prevents the connection terminals from shifting relative to the surface plate of the case, which has a terminal window, thereby achieving the characteristic of effectively preventing problems such as poor contact. Furthermore, the structure in which the circuit board is sandwiched and held in a fixed position between the battery unit and the surface plate also achieves the characteristic of effectively preventing poor contact when used for a long period of time.

The battery pack is set in the external device, and the connection terminal comes into contact with an elastically deforming terminal, i.e., an elastic terminal, provided on the external device to establish an electrical connection. The elastic terminal elastically deforms and is pressed against the surface of the connection terminal to establish an electrical connection. The elastic terminal is pressed against the connection terminal of the battery pack with a certain contact pressure to establish a normal electrical connection, so a reduction in contact pressure can cause poor contact. Misalignment of the connection terminal of the battery pack, particularly misalignment of the connection terminal in the pressing direction of the elastic terminal, can reduce the contact pressure and cause poor contact.

The above battery pack has the connection terminals fixed to the circuit board, and the circuit board is sandwiched between the battery unit and a surface plate with a terminal window to position the connection terminals in a fixed position. Therefore, even when the battery pack is set in an external device and the connection terminals are elastically pressed by an elastic terminal, the circuit board to which the connection terminals are fixed is prevented from shifting out of position. This is because the circuit board is sandwiched between the surface plate and the battery unit, which prevents the circuit board from shifting out of position. When set in an external device and elastically pressed by the elastic terminal of the external device, the connection terminals do not shift out of position, and changes in contact pressure with the elastic terminal of the external device are suppressed. Therefore, even when used for a long period of time, the connection terminals are reliably and stably electrically connected to the elastic terminal of the external device, realizing the feature of preventing poor contact.

In another embodiment of the battery pack of the present invention, the outer periphery of the circuit board and the cell holder are connected by a fitting structure in which a fitting protrusion is guided into a fitting recess, and the circuit board is connected to a fixed position on the cell holder.

The above battery packs have a circuit board that is connected to a fixed position in the cell holder using a fitting structure, so the connection terminals of the circuit board, which are clamped and positioned between the battery unit and the surface plate of the case, can be positioned in the terminal window of the case with greater precision.

In another embodiment of the battery pack of the present invention, the circuit board has a mating recess on the outer periphery, and the cell holder has a mating protrusion that is guided into the mating recess to place the circuit board in a fixed position, and the circuit board is connected to the cell holder in a fixed position by a mating structure in which the mating protrusion is guided into the mating recess.

The above battery pack has a mating recess on the outer periphery of the circuit board, which makes it easy to form the mating recess, while the mating structure with the mating protrusion on the cell holder allows the circuit board to be securely connected to the cell holder in a fixed position.

In another embodiment of the battery pack of the present invention, the circuit board has mating recesses on both sides of the terminal area where the connection terminals are provided.

The circuit board of the above battery pack has mating recesses on both sides of the terminal area, so the circuit board can be connected to the cell holder without misalignment, preventing misalignment of the connection terminals.

In another embodiment of the battery pack of the present invention, the circuit board has connection terminals on its front surface, and the cell holder is integrally formed with multiple support ribs that support the back surface of the circuit board.

The above battery pack has the advantage that the rear surface of the circuit board is supported by multiple support ribs on the cell holder, preventing misalignment of the circuit board, particularly in the direction in which it is pressed against the terminals of an external device, and thus more effectively preventing poor contact.

In a battery pack according to another embodiment of the present invention, the cell holder and the case are connected by a locking structure between a holder locking portion provided on the cell holder and a case locking portion provided on the case.

The above battery pack has an interlocking structure that connects the cell holder and the case, so it can be easily assembled by interlocking the holder interlocking portion with the case interlocking portion to connect the battery unit and the case.

A battery pack according to another embodiment of the present invention includes a box-shaped case formed into a box shape with a peripheral wall consisting of side walls and end walls around a surface plate, and a lid case that closes the opening of the box-shaped case, and the box-shaped case has a terminal window opened in the surface plate. A cell holder is connected to the box-shaped case with a locking structure, a circuit board is sandwiched between the cell holder and the box-shaped case, and a connection terminal is positioned at the exposed position of the terminal window.

In another embodiment of the battery pack of the present invention, the box-shaped case has a case locking portion that protrudes from the inner surface of a pair of side walls, and the cell holder has a holder locking portion that locks into the case locking portion.

In another embodiment of the battery pack of the present invention, a pair of side walls of a box-shaped case includes a vertical side wall connected to a surface plate in a vertical position and an inclined side wall connected to the surface plate in an inclined position, and the case locking portion includes a first case locking portion provided on the inner surface of the vertical side wall and a second case locking portion provided on the inner surface of the inclined side wall, with the first case locking portion protruding higher than the second case locking portion.

The battery pack described above can be smoothly inserted into the box-shaped case and connected in place by engaging one holder locking portion of the cell holder with the first case locking portion on the vertical side wall, inserting the battery unit while tilting it into the box-shaped case, and engaging the other holder locking portion of the cell holder with the second case locking portion on the inclined side wall.

In another embodiment of the battery pack of the present invention, the surface plate has a terminal window at the side edge where the vertical side wall is connected.

The above battery pack has a box-shaped case with a vertical side wall connected to the side edge on the side of the terminal window opened in the surface plate, and an inclined side wall on the opposite side edge. This increases the connection strength between the side wall on the side where the terminal window is opened and the surface plate, reducing misalignment of the circuit board that is engaged here and allowing the connection terminal to be accurately positioned relative to the terminal window.

In a battery pack according to another embodiment of the present invention, the side walls of the box-shaped case have elasticity that allows the holder locking portion to move beyond the case locking portion to the locking position, and the side walls elastically deform to position the holder locking portion at the locking position of the case locking portion.

The above battery pack has the advantage that the side walls of the box-shaped case can be elastically deformed to easily insert the battery unit into the box-shaped case, and the battery unit can be connected to the box-shaped case in a fixed position using a locking structure.

In another embodiment of the present invention, the battery pack has a box-shaped case with a vertical side wall connected to the surface plate at a right angle and an inclined side wall connected to the surface plate at an obtuse angle, and the inclined side wall has a curved shape with its center protruding outward.

The above battery pack has the advantage that the battery unit can be easily and smoothly inserted into the box-shaped case and can be connected to the box-shaped case using a locking structure.

In a battery pack according to another embodiment of the present invention, the case locking portion has an inclined surface that slopes upward in the insertion direction of the holder locking portion, and the holder locking portion moves along the inclined surface to be guided to the locking position of the case locking portion.

The above battery pack allows the holder locking part to slide along the inclined surface and move smoothly to the locking position of the case locking part, so the battery unit can be smoothly inserted into the box-shaped case and connected with the locking structure.

The present invention will be described in detail below with reference to the drawings. In the following description, terms indicating specific directions or positions (e.g., "upper", "lower", and other terms including these terms) are used as necessary, but the use of these terms is for the purpose of facilitating understanding of the invention with reference to the drawings, and the meaning of these terms does not limit the technical scope of the present invention. In addition, parts with the same reference numerals appearing in multiple drawings indicate the same or equivalent parts or members.
Furthermore, the embodiments shown below are specific examples of the technical ideas of the present invention, and do not limit the present invention to the following. Furthermore, unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of the components described below are intended to be illustrative and not to limit the scope of the present invention. Furthermore, the contents described in one embodiment or example can be applied to other embodiments or examples. Furthermore, the sizes and positional relationships of the components shown in the drawings may be exaggerated to clarify the explanation.

(Embodiment 1)
A battery pack according to a first embodiment of the present invention is shown in Figures 1 to 4. Figure 1 is a perspective view of the battery pack, Figure 2 is an exploded perspective view of the battery pack in Figure 1, Figure 3 is an exploded perspective view of the battery pack in Figure 2 seen from below, and Figure 4 is a vertical cross-sectional view taken along line IV-IV of the battery pack in Figure 1. The battery pack 100 shown in these figures includes a battery unit 10 in which multiple battery cells 1 are connected to a cell holder 2, a circuit board 3 connected to a fixed position of the battery unit 10, and a case 4 in which the circuit board 3 and the battery unit 10 are housed.

(Battery unit 10)
A battery unit 10 has multiple battery cells 1 arranged in parallel at fixed positions using cell holders 2. The battery cells 1 are cylindrical batteries, and preferably non-aqueous electrolyte secondary batteries such as lithium ion secondary batteries can be used, but the present invention does not limit the battery cells 1 to cylindrical batteries or non-aqueous electrolyte secondary batteries, and any secondary batteries currently in use or to be developed in the future can be used.

(Cell holder 2)
The cell holder 2 is made by molding insulating plastic. The cell holder 2 shown in Figures 2 to 5 has two rows of grooves 21 on the front side to guide two cylindrical batteries. End plates 22 are provided on both ends of the grooves 21 to position the end faces of the cylindrical batteries on the inside. The back side of the cell holder 2 has multiple support ribs 23 to support the planar circuit board 3, mating protrusions 24 to connect the circuit board 3 in a fixed position, and a locking portion 6 that connects to the case 4 in a fixed position with a locking structure.

The groove 21 is shaped to fit the outer periphery of the cylindrical battery, and guides the cylindrical battery into the groove to position it in place. The cylindrical battery is guided into the groove 21 and can be attached to the cell holder 2 with double-sided adhesive tape to prevent it from shifting out of position. The end plate 22 has through holes 22a that expose the positive and negative electrodes on both ends of the cylindrical battery, and the lead plates 11 are welded to the electrodes exposed in the through holes 22a, electrically connecting the battery cells 1 with the lead plates 11. The battery unit 10 in the figure connects two battery cells 1 in series with the lead plates 11 to make the output voltage twice that of the battery cells 1, but the battery cells 1 can also be connected in parallel.

The groove 21 is molded into a shape that conforms to the cylinder, forming an uneven surface, and a plurality of support ribs 23 are provided at predetermined intervals in the axial direction of the cylinder on the surface facing the circuit board 3. The support ribs 23 protrude perpendicular to the surface facing the circuit board 3 and are arranged vertically to the surface of the circuit board 3 to support the circuit board 3 from the back side. The contact surface of each support rib 23 with the circuit board 3 is arranged on the same plane as the back side of the circuit board 3 so that the planar circuit board 3 can be supported from the back side. The cell holder 2 in FIG. 5 has two rows of support ribs 23 on both sides of the groove 21 that support both sides of the circuit board 3 (the top and bottom of the circuit board 3 in FIG. 5). Furthermore, the cell holder 2 in FIG. 5 has a step portion 25 that fits the lower edge of the circuit board 3 in the figure. The step portion 25 prevents the circuit board 3 from shifting downward in the figure. The cell holder 2 in the figure extends the center of the opposing wall 26 that forms the step portion 25 downward to form a support portion 27 that is placed on the same plane as the circuit board 3. The cell holder 2 can be attached to the inner surface of the case 4 with double-sided adhesive tape 12 so that it does not shift out of position.

Furthermore, the cell holder 2 is provided with a mating protrusion 24 that is guided into the mating recess 34 provided on the outer periphery of the circuit board 3 to prevent the circuit board 3 from being misaligned in the vertical and horizontal directions. The cell holder 2 is provided with the mating protrusion 24 on the back side that faces the circuit board 3. The mating protrusion 24 is guided by the mating recess 34 of the circuit board 3 to place the circuit board 3 in a fixed position on the cell holder 2. The circuit board 3 in Figures 2, 3, and 5 has mating recesses 34 on both sides of the terminal area 31 in which the connection terminals 5 are provided, so that the mating protrusions 24 that are guided into the mating recesses 34 are provided protruding toward the circuit board 3. The mating protrusions 24 that protrude toward the circuit board 3 do not protrude from the surface of the circuit board 3 when they are guided by the mating recess 34 of the circuit board 3. The mating protrusions 24 that do not protrude from the surface of the circuit board 3 do not prevent the connection terminals 5 from coming into close contact with the inner surface of the case 4 when the circuit board 3 is sandwiched between the case 4 and the battery unit 10. The mating protrusions 24 that do not protrude from the surface of the circuit board 3 can clamp the circuit board 3 with a pair of mating protrusions 24, connecting the circuit board 3 in a state in which it is difficult to remove. The cell holder 2 in Figures 1 and 2 guides the mating protrusions 24 into the mating recesses 34 provided on both sides of the terminal area 31 of the circuit board 3, so that it is possible to more effectively prevent the positional deviation of the connection terminals 5 provided on the circuit board 3. The circuit board 3 in the figure has mating recesses 34 on both side edges and upper and lower edges, so that the cell holder 2 has multiple mating protrusions 24 that are inserted into each mating recess 34.

(Circuit board 3)
The circuit board 3 has electronic components (not shown) mounted on an insulating substrate to realize a protection circuit for the battery cells 1. The insulating substrate may be, for example, an epoxy resin substrate reinforced with glass fiber. The protection circuits include a circuit that detects overcharging or overdischarging of the battery and controls the current, a circuit that detects overcurrent in the battery and cuts off the current, and a circuit that detects the temperature of the battery and cuts off the current when the temperature becomes abnormal. The circuit board 3 has electronic components arranged on the surface facing the cell holder 2, and the surface facing the inner surface of the surface plate 41 of the case 4 is flat and has no electronic components mounted thereon. This circuit board 3 is in close contact with the inner surface of the surface plate 41 of the case 4, and the connection terminals 5 of the circuit board 3 can be in close contact with the inner surface of the surface plate 41. However, the circuit board 3 may also have electronic components mounted on the surface facing the inner surface of the surface plate, and the inner surface of the surface plate may have recesses formed thereon to guide the electronic components, so that the connection terminals can be in close contact with the inner surface of the surface plate.

The circuit board 3 is smaller than the outer shape of the cell holder 2 and smaller than the outer shape of the surface plate 41 of the case 4, so that it can be fitted closely to the inner surface of the surface plate 41. The circuit board 3 is required to be large enough to mount a large number of electronic components that realize a protection circuit and to bond multiple connection terminals 5 to its surface, so the circuit board 3 in Figures 1 and 2 is a rectangle smaller than the width (W) and length (L) of the inner surface of the surface plate 41 and is fitted closely to the inner surface of the surface plate 41. The circuit board 3 has a large outer shape so that the connection terminals 5 can be stably and reliably fitted closely to the inner surface of the surface plate 41. The width (H) and length (D) of the circuit board 3 are, for example, 1/2 or more, preferably 3/4 or more, of the inner shape of the surface plate 41, so that the multiple connection terminals 5 can be stably and reliably fitted closely to the inner surface of the surface plate 41.

The connection terminal 5 is a metal plate, which is fixed to the surface of the circuit board 3, facing the inner surface of the surface plate 41 of the case 4. The connection terminal 5 is preferably gold-plated to reduce contact resistance due to the metal oxide film on the surface. However, a metal plate such as nickel without plating can also be used for the connection terminal 5. The connection terminal 5 in the figure has positive and negative power terminals 5a and two signal terminals 5b. The connection terminal 5 has a square shape for the power terminal 5a and the signal terminal 5b, and the positive and negative power terminals 5a are wider than the signal terminals 5b to allow a large current to flow. The positive and negative power terminals 5a are arranged apart, and the signal terminal 5b is arranged between them. The power terminals 5a and the signal terminals 5b are arranged in a straight line in the terminal area 31 of the circuit board 3, and are fixed in an insulated state with a predetermined gap between them. The circuit board 3 in Figures 2 to 5 has a terminal area 31 on the outer periphery (the upper edge in the figures). There are mating recesses 34 on both sides of the terminal area 31 to guide the mating protrusions 24 of the cell holder 2 and prevent misalignment.

The connection terminal 5 is fixed in place by soldering to the conductive portion of the circuit board 3 and electrically connecting it to the conductive portion. The connection terminal 5 has a connection lead (not shown) protruding from the outer periphery in order to be soldered to the conductive portion of the circuit board 3. The connection lead is inserted into a through hole (not shown) in the circuit board 3 and soldered to the conductive portion provided on the back surface. The connection terminal 5 is fixed in place on the circuit board 3 via the connection lead that penetrates the circuit board 3 and is soldered to the conductive portion. The connection terminal 5 is placed in place on the case 4 via the circuit board 3 that is sandwiched between the surface plate 41 of the case 4 and the cell holder 2 and placed in place.

The circuit board 3 has mating recesses 34 on its outer periphery to connect to the cell holder 2 at a fixed position. The mating protrusions 24 of the cell holder 2 are guided into the mating recesses 34 to connect to the cell holder 2 at a fixed position. The circuit board 3 in Figures 2, 3, and 5 has mating recesses 34 on its upper and lower edges to prevent vertical misalignment, and mating recesses 34 on both left and right side edges to prevent horizontal misalignment. The mating recesses 34 on the upper edge are located on both sides of the terminal area 31, and two mating recesses 34 are provided on the lower edge and both side edges. Each mating recess 34 guides the mating protrusions 24 on the cell holder 2 to place the circuit board 3 in a fixed position. The mating protrusions 24 guided by the upper and lower edges of the circuit board 3 can resiliently pinch the circuit board 3 from above and below, connecting it in a state in which it is difficult to come off, and the mating protrusions 24 guided by the left and right mating recesses 34 can also resiliently pinch the circuit board 3 from the left and right, connecting it in a state in which it is difficult to come off.

(Case 4)
The battery pack 100 in Fig. 1 to Fig. 4 is composed of a box-shaped case 4A and a lid case 4B which are molded separately. The box-shaped case 4A is molded from plastic into a rectangular box shape with a peripheral wall consisting of a side wall 42 and an end wall 43 around a surface plate 41. The lid case 4B is molded into a box shape with a peripheral wall lower than that of the box-shaped case 4A, and the box-shaped case 4A and the lid case 4B are connected by the peripheral wall, and the opening of the box-shaped case 4A is closed by the lid case 4B. The case 4 is assembled by inserting the battery unit 10 into the box-shaped case 4A and connecting the lid case 4B to the box-shaped case 4A. The box-shaped case 4A has a pair of side walls 42 composed of a vertical side wall 42A connected at a right angle to the surface plate 41 and an inclined side wall 42B connected to the surface plate 41 at an angle. In the case 4 shown in the figures, the peripheral walls of the box-shaped case 4A and the lid case 4B are connected. The box-shaped case 4A and the lid case 4B can be connected with a locking structure, a fitting structure, ultrasonic welding, or adhesive. The case 4 shown in the figures has connecting hooks 48 on the peripheral wall of the box-shaped case 4A, and a hook portion 49 on the lid case 4B for hooking the connecting hooks 48, and is connected with a locking structure.

The box-shaped case 4A has a terminal window 44 opened in the surface plate 41 at a position where the connection terminal 5 is exposed. The inner shape of the terminal window 44 is smaller than the outer shape of the connection terminal 5, in other words, the outer shape of the connection terminal 5 is larger than the inner shape of the terminal window 44, and the connection terminal 5 is exposed to the entire inside of the terminal window 44. The battery pack 100 sandwiches the circuit board 3 between the surface plate 41 of the box-shaped case 4A and the cell holder 2, positions the circuit board 3 in a fixed position so as not to shift, and exposes each connection terminal 5 in the terminal window 44. The box-shaped case 4A and the cell holder 2 are connected via a locking portion 6 so that the surface plate 41 of the case 4 and the cell holder 2 hold the circuit board 3 in a sandwiched state and position the connection terminal 5 in a fixed position.

(Lockage structure between case 4 and cell holder 2)
The box-shaped case 4A and the cell holder 2 are connected by a locking structure, the battery unit 10 is placed in a fixed position in the box-shaped case 4A, and the circuit board 3 is sandwiched between the surface plate 41 of the box-shaped case 4A and the cell holder 2, so that the circuit board 3 is in close contact with the inner surface of the surface plate 41. The locking structure shown in Figures 2 to 4 includes a case locking portion 7 protruding from the inside of a pair of side walls 42 of the box-shaped case 4A and a holder locking portion 8 provided on the cell holder 2, and the battery unit 10 is connected to the case 4 by locking the holder locking portion 8 to the case locking portion 7. As shown in the cross-sectional view of Figure 4, the case locking portion 7 has an inclined surface 7c that slopes upward toward the insertion direction of the holder locking portion 8. When the battery unit 10 is inserted into the box-shaped case 4A, this case locking portion 7 allows the holder locking portion 8 of the cell holder 2 to slide along the inclined surface 7c, smoothly guiding it to the locking position of the case locking portion 7.

(Case locking portion 7)
2 and 3 has a U-shape in plan view, with upwardly inclined ribs 7a connected to both sides of the main body wall 7b. The inclined ribs 7a are provided in an orientation that extends in the insertion direction of the battery unit 10, and are molded as an integral structure with the side wall 42. The inclined ribs 7a of this case locking portion 7 also act as ribs that reinforce the main body wall 7b, connecting the main body wall 7b to the side wall 42 with sufficient strength.

The box-shaped case 4A has a vertical side wall 42A connected to the surface plate 41 at a right angle and an inclined side wall 42B connected to the surface plate 41 at an obtuse angle, and the inclined side wall 42B has a curved shape that protrudes outward at the center. As shown in the exploded cross-sectional view of FIG. 6, the curved shape of the inclined side wall 42B is shaped to follow the path of the movement of the lower surface of the battery unit 10 when the battery unit 10 is rotated in the direction indicated by arrow A in a state in which the upper part of the battery unit 10 is inserted into the corner between the surface plate 41 and the vertical side wall 42A of the box-shaped case 4A. As shown in FIG. 6, the box-shaped case 4A of this shape can smoothly insert the battery unit 10 and move the holder locking part 8 of the cell holder 2 to the locking position of the case locking part 7. The vertical side wall 42A has a first case locking part 7A that protrudes on the inner surface, and the inclined side wall 42B has a second case locking part 7B that protrudes on the inner surface. The first case locking portion 7A is higher than the second case locking portion 7B, in other words, the second case locking portion 7B is lower than the first case locking portion 7A.

The box-shaped case 4A shown in the figure has a vertical side wall 42A connected to one side edge of the surface plate 41, the side edge on the side where the terminal window 44 is opened, and an inclined side wall 42B connected to the opposite side edge. In other words, the box-shaped case 4A has the vertical side wall 42A connected to the side edge on the side where the end of the battery unit 10 is inserted, where the terminal area 31 of the connection terminal 5 arranged opposite the terminal window 44 is arranged. This structure has the feature that the holder locking part 8 on the upper end of the cell holder 2, where the connection terminal 5 is arranged, can be locked to the first case locking part 7A provided on the vertical side wall 42A to provide reliable support.

Furthermore, the side walls 42 of the box-shaped case 4A are molded from plastic to a thickness that allows elastic deformation. When the battery unit 10 is set in a fixed position inside the box-shaped case 4A, as shown in FIG. 7, the holder locking portion 8 of the cell holder 2 moves beyond the case locking portion 7 to the locking position, and this elastic deformation occurs. This allows the battery unit 10 to be smoothly inserted into the box-shaped case 4A while still providing a more secure locking structure, i.e., the holder locking portion 8 penetrates deeply into the case locking portion 7 to lock it in place, preventing it from coming loose.

(Holder locking portion 8)
The cell holder 2 is provided with a first holder locking portion 8A that is locked to the first case locking portion 7A and a second holder locking portion 8B that is locked to the second case locking portion 7B, at locking positions of the case locking portion 7. In Figures 2 and 3, the cell holder 2 is provided with the first holder locking portion 8A on its upper surface and the second holder locking portion 8B on its lower surface. As shown in Figures 4, 5, and 8, the first holder locking portion 8A is plate-shaped with a locking surface that is locked in surface contact with the main body wall 7b of the first case locking portion 7A, and both side edges are connected to the support ribs 23. 3 and 9, the second holder locking portion 8B is plate-shaped with a locking surface that is locked in surface contact with the main body wall 7b of the second case locking portion 7B, with one side edge connected to the support portion 27 connected to the groove portion 21 and the other side edge connected to the end plate portion 22. The holder locking portion 8 having this shape is integrally connected to the cell holder 2 with sufficient strength via the support rib 23, the support portion 27, or the end plate portion 22, so that the holder locking portion 8 can be connected to the cell holder 2 with sufficient strength. A battery pack 100 in which the case locking portion 7 of the side wall 42 is connected to the side wall 42 with high strength via the inclined rib 7a and the holder locking portion 8 is connected to the cell holder 2 with high strength via the support rib 23, the end plate portion 22, etc. can increase the connection strength between the cell holder 2 and the case 4. This battery pack 100 has the advantage that the circuit board 3 is firmly sandwiched between the surface plate 41 and the cell holder 2 , and the connection terminals 5 can be reliably brought into close contact with the inner surface of the surface plate 41 .

As shown in Figures 6 and 7, the box-shaped case 4A and battery unit 10 described above have the advantage that the corner of the battery unit 10 where the first holder locking portion 8A is provided is inserted first into the box-shaped case 4A, the battery unit 10 is inserted while tilting into the box-shaped case 4A, and the first holder locking portion 8A is locked into the locking position of the first case locking portion 7A, allowing the battery unit 10 to be smoothly inserted into the box-shaped case 4A while being locked securely in a state that is difficult to come loose.

The above battery pack 100 can be assembled in the following steps.
2 and 3 , the circuit board 3 is connected to the cell holder 2 in a fixed position using a fitting structure, and the connection terminals 5 are connected to the circuit board 3. The cell holder 2 connects the battery cells 1 to their grooves 21.
(2) The battery unit 10, in which the battery cells 1 and the circuit board 3 are connected in fixed positions, is guided into the peripheral wall of the box-shaped case 4A, and the case 4 and the cell holder 2 are connected by an engagement structure, and the battery unit 10 is connected in a fixed position in the box-shaped case 4A. The cross-sectional views of Fig. 6 and Fig. 7 show the state in which the battery unit 10 is inserted into the box-shaped case 4A. First, as shown in the cross-sectional view of Fig. 6, the battery unit 10 is in an inclined position, and the upper part of the cell holder 2 in the figure is guided first into the box-shaped case 4A, and the first holder locking part 8A is positioned inside the first case locking part 7A. Then, the battery unit 10 in the inclined position is rotated in the direction indicated by the arrow A, and the lower part of the battery unit 10 is inserted into the peripheral wall of the box-shaped case 4A. In this state, as shown in Fig. 7, the side wall 42 of the box-shaped case 4A is elastically deformed, and the second holder locking part 8B is guided beyond the second case locking part 7B to the locking position (see Fig. 4). As shown in Fig. 8, the first holder locking portion 8A is locked to the first case locking portion 7A, and as shown in Fig. 9, the second holder locking portion 8B is locked to the second case locking portion 7B, and the battery unit 10 is placed in a fixed position in the box-shaped case 4A. In this state, the circuit board 3 is sandwiched between the cell holder 2 and the surface plate 41 of the box-shaped case 4A, and the connection terminals 5 are placed in a fixed position. The circuit board 3, which is sandwiched and held in a fixed position, is in close contact with the inner surface of the surface plate 41, and the connection terminals 5 provided on the surface are placed in close contact with the inside of the terminal window 44.
(3) After the battery unit 10 is placed in place in the box-shaped case 4A, the cover case 4B is connected to the opening of the box-shaped case 4A to complete the battery pack 100.

The battery pack according to the present invention has a connection terminal in the terminal window 44 of the case and is suitable for use as a power source for portable devices such as cameras, music players, and power tools.

DESCRIPTION OF SYMBOLS 100...battery pack 1...battery cell 2...cell holder 3...circuit board 4...case 4A...box-shaped case 4B...lid case 5...connection terminal 5a...power terminal 5b...signal terminal 6...locking portion 7...case locking portion 7A...first case locking portion 7B...second case locking portion 7a...inclined rib 7b...main body wall 7c...inclined surface 8...holder locking portion 8A...first holder locking portion 8B...second holder locking portion 10...battery unit 11...lead plate 12...double-sided adhesive tape 21...groove portion 22...end plate portion 22a...through hole 23...support rib 24...fitting protrusion 25...step portion 26...opposing wall 27...support portion 31...terminal area 34...fitting recess 41...surface plate 42...side wall 42A...vertical side wall 42B...inclined side wall 43...end wall 44...terminal window 48...connecting hook 49...hook portion

Claims (11)

a battery unit in which battery cells are arranged in fixed positions using cell holders;
a circuit board disposed at a fixed position of the battery unit;
a case that houses the circuit board and the battery unit;
Equipped with
the circuit board has a plurality of connection terminals fixed to a surface thereof for connection to an external device;
the case includes a surface plate having a terminal window through which the connection terminal is exposed to the outside,
the circuit board is connected to a fixed position of the cell holder, and is sandwiched between the battery unit and the surface plate having the terminal window opened therein, and is disposed at a fixed position within the case, with the connection terminals exposed to the terminal window ;
the cell holder and the case are connected by a locking structure in which a holder locking portion provided on the cell holder and a case locking portion provided on the case are connected by a locking structure,
The case,
a box-shaped case formed into a box shape by providing a peripheral wall consisting of a side wall and an end wall around the surface plate;
a cover case that closes the opening of the box-shaped case,
The box-shaped case has the terminal window opened in the surface plate,
The cell holder is connected to the box-shaped case by the locking structure, the circuit board is sandwiched between the cell holder and the box-shaped case, and the connection terminal is disposed in an exposed position of the terminal window . 2. The battery pack according to claim 1,
The outer peripheral edge of the circuit board and the cell holder are connected by a fitting structure in which a fitting convex portion is guided into a fitting concave portion, and the circuit board is connected to a fixed position of the cell holder in the battery pack. 3. The battery pack according to claim 2,
The circuit board has a fitting recess on an outer periphery thereof,
the cell holder has a fitting protrusion that is guided by the fitting recess to place the circuit board in a fixed position,
The battery pack has a fitting structure in which the fitting convex portion is guided into the fitting concave portion, and the circuit board is connected to a fixed position of the cell holder. 4. The battery pack according to claim 2 or 3,
The circuit board has a terminal area on both sides of which the connecting terminals are provided, and the fitting recesses are provided on the circuit board. 5. The battery pack according to claim 1,
the circuit board has the connection terminals on a surface thereof;
The cell holder is integrally formed with a plurality of support ribs for supporting the rear surface of the circuit board. 6. The battery pack according to claim 1 ,
the box-shaped case has the case engaging portions protruding from the inner surfaces of the pair of side walls,
The cell holder has a holder locking portion that is locked to the case locking portion. 7. The battery pack according to claim 6 ,
The pair of side walls of the box-shaped case are
A vertical side wall connected to the surface plate in a vertical position;
a slanted side wall connected to the surface plate in an inclined position;
a first case engaging portion provided on an inner surface of the vertical side wall;
a second case engaging portion provided on an inner surface of the inclined side wall,
The battery pack has the first case engaging portion protruding higher than the second case engaging portion. 8. The battery pack according to claim 7 ,
The battery pack has the terminal window formed in the side edge of the surface plate to which the vertical side wall is connected. 9. The battery pack according to claim 7 or 8 ,
the side wall of the box-shaped case has elasticity that allows the holder locking portion to move beyond the case locking portion to a locking position;
The side wall is elastically deformed, and the holder locking portion is disposed at the locking position of the case locking portion. 10. The battery pack according to claim 6 ,
The pair of side walls of the box-shaped case are
the vertical side wall perpendicularly connected to the surface plate;
the inclined side wall being connected to the surface plate at an obtuse angle;
The battery pack has a curved shape in which the inclined side wall protrudes outward from a central portion. 9. The battery pack according to claim 8 ,
The case locking portion is
The holder has an inclined surface with an upward inclination toward the insertion direction of the holder locking portion,
The holder locking portion moves along an inclined surface and is guided to a locking position of the case locking portion.

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