JP5555113B2 - Battery pack and electric tool provided with the battery pack - Google Patents

Description

  The present invention relates to a battery pack and a power tool including the battery pack, and more particularly to a battery pack in which a plurality of battery cells are held in a cell case and housed in a housing, and a power tool including the battery pack. It is.

  Conventionally, a battery pack used for a power source of a cordless electric tool or the like is known (for example, see Patent Document 1). This battery pack includes a plurality of battery packs in which a plurality of battery cells are arranged in a row direction intersecting with the longitudinal direction of the battery cells, a pair of cell cases, and a partition plate. The pair of cell cases are sandwiched from the upper and lower sides in a state where the assembled batteries are stacked in the vertical direction intersecting the longitudinal direction and the column direction. The partition plate is interposed between the stacked assembled batteries and holds the battery cells. And a cell block is comprised by hold | maintaining each said battery cell between the said cell case and a partition plate, or between the said adjacent partition plates. The cell block is accommodated in the housing, and flat cushioning materials are fixed to both sides of the cell block in the front-rear direction.

  As shown in FIG. 10, the buffer material 8 is fixed to the end face of the cell block 2 formed by holding the battery cell 5 in the cell case 6. A rib 90 protruding from the inner surface 3 a of the housing 3 presses the end surface 5 c of the battery cell 5 through the buffer material 8. As a result, the cell block 2 is held by the rib 90, and the positional deviation of the cell block 2 in the housing 3 is restricted.

JP 2010-50044 A

  By the way, in the conventional example, when an impact or vibration due to dropping or the like is applied to the battery pack, the impact is easily transmitted directly to the battery cell 5 through the rib 90 protruded from the housing 3, and adversely affects the battery cell 5. there is a possibility.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a battery pack capable of attenuating impact applied to the battery cell from the outside and protecting the battery cell, and the battery. An object is to provide an electric tool including a pack.

In order to solve the above problems, the present invention provides an assembled battery in which a plurality of battery cells are arranged in a column direction orthogonal to the longitudinal direction of the battery cell, and the assembled battery is arranged in the longitudinal direction and the column direction. A battery pack that is stored and held in a housing sandwiched and held from a direction orthogonal to both, between the end surface in the longitudinal direction of the cell case and the inner surface of the housing facing the battery case. The distance of the battery case from the inner surface of the housing to the distance between the end face in the longitudinal direction of the battery cell and the inner surface of the housing opposite to the distance is reduced. It is characterized by protruding ribs toward the end face in the longitudinal direction .

Further, the longitudinal end surface of the cell case than said longitudinal end surface of the battery cell, it is preferable to project toward an inner surface of said housing opposite.

In addition, it is preferable that a cushioning material is disposed between the end surface of the cell case in the longitudinal direction and the inner surface of the housing facing the end surface .

  The electric power tool of the present invention is characterized in that the battery pack is detachably mounted.

  The present invention can attenuate the impact applied to the battery cell from the outside and protect the battery cell.

It is an example of embodiment of the battery pack of this invention, (a) is a plane sectional view which follows the AA line of FIG. 2, (b) is an enlarged view of the D section of (a). It is a front view of a battery pack same as the above. It is a perspective view of a battery pack same as the above. It is an expanded view of a battery pack same as the above. It is an expanded view of the cell block built in a battery pack same as the above. It is explanatory drawing of other embodiment of this invention. It is explanatory drawing of other embodiment of this invention. It is explanatory drawing of other embodiment of this invention. It is the schematic of the electric tool which attached the battery pack same as the above so that attachment or detachment was possible. It is explanatory drawing of a prior art example.

  Hereinafter, an example of an embodiment of a battery pack will be described with reference to the drawings.

  FIG. 3 is a perspective view of the battery pack 1 of the present embodiment. The battery pack 1 is used as a power source for an electric tool 50 (see FIG. 9) such as a cordless impact driver and is configured to be detachable from the electric tool 50. The battery pack 1 can be supplied with power by being attached to the electric tool 50 and can be charged by being removed from the electric tool 50 and connected to a charger (not shown).

  The housing 3 of the battery pack 1 is formed in a substantially rectangular parallelepiped shape. The housing 3 of this example includes an upper housing 21, an intermediate frame member 23, and a lower housing 22. In this example, the upper housing 21 and the intermediate frame member 23 are integrated.

  FIG. 4 is a development view of the battery pack 1. Screw fixing portions 27 protrude downward from the four corners of the lower end of the upper housing 21, respectively. A pedestal portion 30 protruding upward is formed on the upper lid portion 25 of the upper housing 21 so as to bulge out. In this pedestal portion 30, three insertion grooves 31 into which connection terminals (not shown) of the electric tool 50 (see FIG. 9) are inserted and locking pieces (not shown) of the electric tool 50 are inserted and engaged. Three pairs of left and right hooks 32a, 32b and 32c are provided. In addition, 45 in FIG. 4 is a lock button that is slid when the engaging piece of the electric power tool 50 is attached to or detached from the hooks 32 a to 32 c of the upper housing 21. 45a is a spring for holding the lock button 45 and providing operability.

On the other hand, the lower cover portion 34 of the lower housing 22 is formed in a substantially flat plate shape, and has a wall portion 35 extending upward along its outer peripheral edge. At the four corners of the inner bottom surface 34 a of the lower lid portion 34, lower housing side connecting portions 36 are formed at positions corresponding to the screw fixing portions 27 of the upper housing 21. A screw insertion hole 37 is formed in the lower housing side connecting portion 36 so as to penetrate in the vertical direction so as to be collinear with the screw fixing portion 27 of the upper housing 21.

  The intermediate frame member 23 (see FIG. 3) is formed in a substantially square frame shape. Screw insertion holes (not shown) opened up and down are formed at the four corners on the inner peripheral side of the intermediate frame member 23.

Then, the screw 43 shown in FIG. 4 is inserted from below the screw insertion hole 37 of the lower housing 23 and screwed into the screw fixing portion 27 of the upper housing 21 through the screw insertion hole of the intermediate frame member 23 (see FIG. 3). To do. Thereby, each housing 21-23 is assembled to the housing 3 (refer FIG. 1). The cell block 2 is accommodated and held in the housing 3.

  FIG. 5 is a development view of the cell block 2. The cell block 2 of this example includes a plurality of (in this embodiment, two upper and lower) assembled batteries 4, two connecting plates 65 (one not shown) connected to the assembled battery 4, a positive terminal 66, and a negative electrode A terminal 67 and a control circuit 68 for controlling charge / discharge of the assembled battery 4 and the like are provided.

  First, in the assembled battery 4, a plurality (three in this embodiment) of battery cells 5 are arranged adjacent to each other in the column direction F perpendicular to the longitudinal direction E of the battery cells 5. Each battery cell 5 is formed in a cylindrical shape, and a positive electrode 56a is formed on one end face in the longitudinal direction E, and a negative electrode 56b is formed on the other end face. Each battery cell 5 is arranged such that adjacent positive electrodes 56a and negative electrodes 56b are staggered. Note that a secondary battery such as a lithium ion secondary battery is used for the battery cell 5.

  The two connecting plates 65 (one not shown) are arranged on both sides of the cell block 2 to connect the assembled batteries 4 in parallel and connect the battery cells 5 in each assembled battery 4 in series to each other. To do. The positive terminal 66 is electrically connected to the positive electrode 56a of the last row of each assembled battery 4, and the negative terminal 67 is electrically connected to the negative electrode 56b of the last row of each assembled battery 4. The positive terminal 66 and the negative terminal 67 are for taking out electric power from each assembled battery 4, and are electrically connected to the control circuit 68.

  The connecting plate 65, the positive electrode terminal 66, and the negative electrode terminal 67 are all made of sheet metal parts, and are fixed to the upper cell case 52 (see FIG. 4) side. The connecting plate 65, the positive electrode terminal 66, and the negative electrode terminal 67 are fixed to the positive electrode 56a and the negative electrode 56b of each battery cell 5 by welding. The control circuit 68 is provided with a plurality (three in this embodiment) of connection terminals 71 connected to terminals (not shown) of the electric tool 50 (see FIG. 9). Each connection terminal 71 is disposed at a position corresponding to the insertion groove 31 (see FIG. 4) of the upper housing 21, and a predetermined voltage based on each assembled battery 4 is generated between the predetermined connection terminals 71. ing.

  Next, the cell block 2 will be described. As shown in FIG. 5, the cell block 2 is interposed between a cell case 6 that sandwiches the assembled batteries 4 from both the upper and lower sides in a state where the assembled batteries 4 are stacked in two stages, and the stacked assembled batteries 4. Partition plate 54.

  The cell case 6 is divided into an upper cell case 52 and a lower cell case 53. The upper cell case 52 is formed in a corrugated plate shape having a plurality of (three in the present embodiment) concave portions 58 having a semicircular cross section that opens downward. The lower cell case 53 is formed in a corrugated plate shape having a plurality of (in the present embodiment, three) concave portions 59 having a semicircular cross section opened upward. Each of the recesses 58 and 59 is formed so that the inner diameter thereof is substantially the same as the outer diameter of the battery cell 5. That is, the depths of the recesses 58 and 59 are formed to be equal to the radius of the battery cell 5. Accordingly, a part of the outer peripheral surface of each battery cell 5 is brought into close contact with each of the recesses 58 and 59.

  A partition plate 54 is disposed between the upper cell case 52 and the lower cell case 53. The partition plate 54 includes a flat plate-like main body portion 61 and a plurality of (four in the present embodiment) partition walls (not shown) standing on both upper and lower surfaces of the main body portion 61. A part of the battery cell 5 can be fitted between each partition wall in a close contact state. The upper cell case 52, the lower cell case 53, and the partition plate 54 are fixed to each other using screws 55. Thus, the upper and lower assembled batteries 4 are arranged and held between the upper cell case 52 and the partition plate 54 and between the partition plate 54 and the lower cell case 53, respectively. That is, each battery cell 5 is individually held between the recesses 58 and 59 of the upper cell case 52 and the lower cell case 53 and the partition plate 54. The partition plate 54 functions to suppress relative movement between the battery cells 5 and to ensure electrical insulation between the battery cells 5 even when vibration or impact is applied to the battery pack 1.

  Next, a structure for protecting the battery cell 5 from an external impact will be described with reference to FIGS. 1, 2, and 5.

  1A is a cross-sectional view taken along line AA in FIG. 2, FIG. 1B is an enlarged view of a portion D in FIG. 1A, and FIG. 2 shows the housing 3 in which the cell block 2 is accommodated. It is a front view.

  In a state in which the cell block 2 is housed and held in the housing 3, as shown in FIG. 1A, the end surface 6a of the cell case 6 and the end surface 5c of the battery cell 5 are arranged substantially flush with each other as viewed from above. Has been. On the other hand, four ribs 7 are projected from a plurality of locations (four locations in the present embodiment) of the inner surface 3 a of the housing 3 toward the end surface 6 a of the cell case 6.

  The four ribs 7 protrude inward over the entire length of the inner surface 3a of the housing 3 in the vertical direction. That is, each rib 7 extends in a straight line from the inner surface of the upper housing 21 (see FIG. 2) to the inner surface of the lower housing 22 through the inner surface of the intermediate frame member 23 (see FIG. 3). .

  The four ribs 7 are disposed so as to be able to come into contact with a total of four locations, two at both ends of the end surface 6a of the cell case 6 and two at the center. In this example, of the four ribs 7, the two ribs 7 on both sides are formed thick, and the two ribs 7 on the center side are formed thin. The two thick ribs 7 on both sides are in contact with two vertically long end faces 58b at both ends of the upper cell case 52 and two vertically long end faces 59b at both ends of the lower cell case 53 shown in FIG. Opposite possible. Two thin ribs 7 on the center side are formed on two narrow end faces 58a on the center side of the upper cell case 52 and two narrow end faces 59a on the center side of the lower cell case 53 shown in FIG. Each is opposed to be able to contact. Hereinafter, the end face 6 a of the cell case 6 is a generic term for the four end faces 58 a and 58 b of the upper cell case 52 and the four end faces 59 a and 59 b of the lower cell case 53.

  Here, in FIG. 1B, the distance between the tip of each rib 7 and the end surface 6a of the cell case 6 is Y, and the distance between the end surface 5c of the battery cell 5 and the inner surface 3a of the housing 3 is X. , The distance X is set to be shorter than the distance Y. That is, the cell block 2 is held in the housing 3 so that the relationship X> Y is established.

  Thus, according to the above configuration, when an impact such as dropping is applied to the battery pack 1, the end surface 6 a of the cell case 6 is in contact with the housing 3 before the end surface 5 c of the battery cell 5 contacts the inner surface 3 a of the housing 3. It comes into contact with the rib 7 projecting from. Thereby, it is avoided that the battery cell 5 contacts the inner surface 3a of the housing 3. As a result, the impact applied to the battery cell 5 can be reduced, and there is an advantage that the possibility of the battery cell 5 being broken can be reduced.

  Further, in this example, four ribs 7 of the housing 3 are provided so as to be distributed and applied to a total of four locations, two at both ends of the end surface 6a of the cell case 6 and two at the center. In addition, the ribs 7 corresponding to the vertically long and wide end faces 58b and 59b of the cell case 6 are formed thick, and the ribs 7 corresponding to the narrow end faces 58a and 59a of the cell case 6 are formed thin. Thereby, the impact from the outside is easily received by the end surface 6 a of the cell case 6 via the rib 7, and at the same time, the impact is distributed to four locations of the cell case 6. Thereby, it becomes difficult for an impact to concentrate on one place of the cell case 6. As a result, in addition to protecting the battery cell 5, the cell case 6 can be protected at the same time.

  Note that the number of ribs 7 is not limited to four, and may be any position that can contact the end surface 6 a of the cell case 6, and the ribs 7 are continuously formed over the entire length of the inner surface 3 a of the housing 3. However, the present invention is not limited to this, and the number and shape of the ribs 7 can be appropriately changed in design.

  FIG. 6 shows another embodiment, in which the end surface 6 a of the cell case 6 protrudes from the end surface 5 c of the battery cell 5 toward the inner surface 3 a side of the housing 3. Other configurations are the same as those of the embodiment of FIG. 1, and corresponding portions are denoted by the same reference numerals. In this example, the distance between the end surface 6a of the cell case 6 and the inner surface 3a of the housing 3 is R, and the distance between the end surface 5c of the battery cell 5 and the inner surface 3a of the housing 3 is X. The cell block 2 is held in the housing 3 so that the relationship of R> Y is established. Therefore, when an impact is applied from the outside, the end surface 6 a of the cell case 6 comes into contact with the inner surface 3 a of the housing 3 before the battery cell 5. Thereby, the impact applied to the battery cell 5 can be reduced. Further, in this example, it is not necessary to project the rib 7 (see FIG. 1) from the inner surface 3a of the housing 3, and the degree of freedom in designing the housing 3 is increased.

  7 and 8 show an example in which the buffer material 8 is arranged on both sides of the cell block 2, respectively. FIG. 7 corresponds to the embodiment of FIG. 1B, and FIG. 8 corresponds to the embodiment of FIG. 6. Corresponding portions are denoted by the same reference numerals and detailed description thereof is omitted.

  In FIG. 7, the rib 7 protruding from the inner surface 3 a of the housing 3 is disposed so as to face the end surface 6 a of the cell case 6 via the cushioning material 8. As a result, when an impact is applied, the rib 7 hits the end surface 6a of the cell case 6 via the cushioning material 8 before the battery cell 5, and at the same time, the impact is alleviated by the cushioning material 8. As a result, vibration and impact applied to the battery cell 5 can be further attenuated.

  In FIG. 8, in the structure in which the end surface 6 a of the cell case 6 protrudes from the battery cell 5 to the inner surface 3 a of the housing 3, the end surface 6 a of the cell case 6 abuts against the inner surface 3 a of the housing 3 through the cushioning material 8. Oppositely arranged as possible. As a result, when an impact is applied, the end surface 6 a of the cell case 6 hits the inner surface 3 a of the housing 3 via the buffer material 8 before the battery cell 5, and at the same time, the shock is alleviated by the buffer material 8. As a result, vibration and impact applied to the battery cell 5 can be further attenuated.

  In the above embodiment, the case where the housing 3 is configured by interposing the intermediate frame member 23 between the upper housing 21 and the lower housing 22 is not limited to this, but depending on the size of the cell block 2, It is possible to change the shapes of the upper housing 21 and the lower housing 22 and to omit the intermediate frame member 23.

DESCRIPTION OF SYMBOLS 1 Battery pack 2 Cell block 3 Housing 3a Housing inner surface 4 Battery assembly 5 Battery cell 6 Cell case 6a Cell case end surface 7 Rib 8 Buffer 50 Electric tool X Distance between housing inner surface and battery cell end surface Y Between rib end and cell case end surface Distance of

Claims (4)

An assembled battery in which a plurality of battery cells are arranged in a column direction orthogonal to the longitudinal direction of the battery cell; and a cell case for holding the assembled battery sandwiched from a direction orthogonal to both the longitudinal direction and the column direction ; Is a battery pack that is housed and held in a housing,
The distance between the longitudinal end face and the inner surface of the housing opposite thereto of the cell case, with respect to the distance between the longitudinal end face and the inner surface of the housing opposite thereto of said battery cell The battery pack is characterized in that ribs protrude from the inner surface of the housing toward the end surface in the longitudinal direction of the cell case facing the housing so as to be shorter. 2. The battery pack according to claim 1 , wherein an end face in the longitudinal direction of the cell case is protruded toward an inner face of the housing opposed to the end face in the longitudinal direction of the battery cell. 3. The battery pack according to claim 1 , wherein a cushioning material is disposed between the end surface of the cell case in the longitudinal direction and the inner surface of the housing facing the end surface . An electric tool, wherein the battery pack according to any one of claims 1 to 3 is detachably mounted.

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