JP2014032862A - Battery cell, battery pack, and power tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery cell capable of preventing shortening from occurring between a first electrode and a second electrode by foreign matter invading from the outside of the first electrode.SOLUTION: The battery cell, having a battery can 21 with an opening 21e communicating with a storage space 22 and a cap 24 provided at the opening 21e of the battery can 21, includes a seal member 32 for preventing shortening from occurring between the battery can 21 and the cap 24 by foreign matter invading from the outside B of the battery can 21.

Description

  The present invention relates to a battery cell having a first electrode and a second electrode having different polarities, a battery pack containing a plurality of battery cells, and an electric tool capable of attaching / detaching the battery pack.

  Conventionally, a battery cell having a first electrode and a second electrode having different polarities is known. A battery pack containing a plurality of battery cells is known. Furthermore, an electric tool to which a battery pack is attached and detached is known. The battery cell, the battery pack, and the electric tool as described above are described in Patent Document 1.

  The electric power tool described in Patent Literature 1 includes a handle portion and a battery pack that can be attached to and detached from the handle portion. The battery pack has a storage case made of a non-conductive member, and the storage case includes a cover and a case body. A holder is housed inside the housing case. The holder has a connection member connected to the electrodes of the plurality of battery cells. The battery pack has a circuit board connected to the connection member. The circuit board is provided with a plurality of pack side terminals.

  Further, the cover is provided with a plurality of terminal insertion holes. The plurality of terminal insertion holes communicate the inside and the outside of the casing, and the plurality of pack-side terminals are individually inserted into the plurality of terminal insertion holes. On the other hand, a plurality of tool-side terminals electrically connected to the electric motor are provided at the lower portion of the handle portion. And the electric tool described in patent document 1 will connect a some tool side terminal and a some pack side terminal, if a battery pack is mounted in a handle part.

  The single battery cell has a structure shown in FIG. 10, for example. The battery cell 100 has a battery can 101 as a first electrode (negative electrode). The battery can 101 includes a body portion 102, an annular holding portion 103, and a constricted portion 104 in which the body portion 102 and the holding portion 103 are continuous. An electrode body 105 is provided inside the battery can 101. The holding portion 103 is bent in a U shape over the entire circumference, and the opening portion of the battery can 101 is formed by the holding portion 103. A cap (a positive electrode as a second electrode) 107, a metal ring 108, a cleavage vent (cleavage valve) 109, and a current interruption vent (current interruption valve) 110 are provided inside the holding unit 103. The current interruption vent 110, the cleavage vent 109, and the metal ring 108 are elements that constitute a path through which current flows between the electrode body 105 and the cap 107.

  Further, a bent portion 110 a that is bent over the entire circumference is provided at the outer peripheral end of the current interruption vent 110. A seal member 111 is interposed between the bent portion 110 a and the holding portion 103. Furthermore, the outer peripheral end of the cleavage vent 109, the outer peripheral end of the metal ring 108, and the outer peripheral end of the cap 107 are disposed inside the bent portion 110a. Further, an annular seal member 112 is provided inside the bent portion 110a. Further, the seal member 112 prevents the bent portion 110 a from coming into contact with the outer peripheral end of the cleavage vent 109, the outer peripheral end of the metal ring 108, and the outer peripheral end of the cap 107. Further, the periphery of the battery can 101 is covered with an insulating tube 115. The insulating tube 115 has an opening 115a, and the cap 107 is exposed from the opening 115a. When the battery cell 100 having the above configuration is accommodated in a battery pack as described in Patent Document 1, the cap 107 is brought into contact with the connection plate 113. Further, the connection plate 113 is insulated from the peripheral elements by the insulating member 114.

JP 2012-51064 A

  However, if the battery pack is placed in an environment where it is exposed to water, water outside the storage case may enter the storage case via the terminal insertion hole. When the water entered the opening of the battery can 101, the cap 107 and the battery can 101 could be short-circuited.

  An object of the present invention is to provide a battery cell, a battery pack, and an electric motor that can prevent foreign matters existing outside the first electrode from entering the opening of the first electrode and short-circuiting the first electrode and the second electrode. To provide a tool.

  The present invention provides a battery cell having a first electrode having an opening communicating with an accommodation space, and a second electrode provided in the opening of the first electrode and having a polarity different from that of the first electrode. In addition, a seal member is provided that prevents the first electrode and the second electrode from being short-circuited by a foreign matter that has entered from the outside of the first electrode.

  The present invention provides a battery cell having a first electrode having an opening communicating with an accommodation space, and a second electrode provided in the opening of the first electrode and having a polarity different from that of the first electrode. In addition, a seal member is provided that prevents the first electrode and the second electrode from being short-circuited by a foreign matter that has entered from the outside of the first electrode.

  The present invention is characterized in that the seal member is disposed apart from the second electrode.

  In the present invention, the seal member is formed in an annular shape along the opening, and is disposed between the first electrode and the connection member that connects the second electrode, and is separated from the second electrode. It is characterized by being arranged.

  According to the present invention, the seal member is configured in an annular shape along the opening and attached to the first electrode, and the seal member is configured such that the second electrode is in contact with a connection member of a battery pack. And contacting the connection member to block the outside of the first electrode and the opening.

  According to the present invention, the seal member is deformed so as to be separated from the connection member when the pressure in the accommodating space of the first electrode is increased, while the seal member is deformed to the connection member when the foreign matter tries to enter the opening. It is characterized by being pressed.

  In the present invention, when the seal member is brought into contact with the connection member, the space formed inside the seal member functions as a buffer for storing the gas discharged from the accommodation space of the first electrode. It is characterized by that.

  The present invention provides an electrode body provided in the housing space of the first electrode, a current path provided in the housing space of the first electrode, and between the electrode body and the second electrode. And an insulating member that is interposed between the first electrode and the conductive member to electrically cut off the first electrode and the conductive member, and the insulating member is the seal It also serves as a member.

  The present invention provides an electrode body provided in the housing space of the first electrode, a current path provided in the housing space of the first electrode, and between the electrode body and the second electrode. And an insulating member that is interposed between the first electrode and the conductive member to electrically cut off the first electrode and the conductive member. It is configured to cover the end of one electrode.

  The present invention is characterized in that the insulating member is connected to a second insulating member that covers an outer periphery of the first electrode.

  The present invention is characterized in that the seal member has water repellency.

  The present invention provides a battery cell having a first electrode having an opening communicating with an accommodation space, and a second electrode provided in the opening of the first electrode and having a polarity different from that of the first electrode. A battery pack including a storage case for storing the battery cell therein, wherein the first electrode and the second electrode are caused by foreign matter that has entered the storage case from outside the first electrode of the battery cell. A seal member is provided to prevent short-circuiting between and.

  The present invention provides a plurality of battery cells in which a second electrode having a polarity different from that of the first electrode is provided in the opening of the first electrode in which an opening communicating with the accommodation space is formed, and the plurality of battery cells A connection member that connects the first electrode and the second electrode, and a storage case that houses the plurality of battery cells and the connection member therein, and the storage case is attached to and detached from the power tool. A battery pack configured to be capable of being provided inside the housing case, connected to the connection member, and provided on the housing case, and inside and outside the housing case. The first electrode and the second electrode are prevented from being short-circuited by a foreign substance that has entered from the outside of the first electrode of the battery cell, and a terminal insertion hole into which the pack-side terminal is inserted. Do Further comprising a seal member, when the housing case is attached to the power tool, the pack side terminal and being connected to the tool-side terminals of the power tool.

  The present invention is characterized in that the seal member is annularly formed along the opening and attached to the first electrode.

  The present invention is characterized in that the seal member is attached to the connection member.

  In the present invention, the seal member is formed in an annular shape along the opening, and the second electrode of the plurality of battery cells is in contact with the connection member when the second electrode is in contact with the connection member. The outside of the first electrode of the plurality of battery cells is blocked from the opening.

  In the present invention, the plurality of battery cells are provided in the accommodation space of the first electrode, in the accommodation space of the first electrode, and in the electrode body and the second A conductive member that forms a current path between the first electrode and the conductive member; and an insulating member that is interposed between the first electrode and the conductive member to electrically cut off the first electrode and the conductive member. The insulating member also serves as the sealing member.

  According to the present invention, the seal member is deformed so as to be separated from the connection member when the pressure in the accommodating space of the first electrode is increased, while the seal member is deformed to the connection member when the foreign matter tries to enter the opening. It is characterized by being pressed.

  In the present invention, when the seal member is brought into contact with the connection member, the space formed inside the seal member functions as a buffer for storing the gas discharged from the accommodation space of the first electrode. It is characterized by that.

  The present invention includes a blocking member that is in contact with a portion of the connecting member that is opposite to a portion that contacts the first electrode, and the sealing member and the connecting member are along a center line of the first electrode. Is disposed between the blocking member and the first electrode, and urethane is applied from the blocking member to the outer surface of the first electrode in the direction along the center line. The outside of the sealing member and the connecting member is covered.

  The present invention is an electric tool including an electric motor, the battery pack according to any one of the above inventions can be attached and detached, and has a tool-side terminal electrically connected to the electric motor, and the battery When the pack is attached, the pack side terminal and the tool side terminal are connected.

  According to the present invention (Claim 1), since the sealing member is provided, it is possible to prevent a foreign substance existing outside the first electrode from entering and short-circuiting the first electrode and the second electrode.

  According to the present invention (Claims 2 and 3), since the seal member and the second electrode are separated from each other, even if water penetrates into the seal member, the first electrode and the second electrode are short-circuited. Can be prevented.

  According to the present invention (Claim 4), when the second electrode is brought into contact with the connection member of the battery pack, the seal member comes into contact with the connection member, thereby blocking the outside of the first electrode from the opening. Therefore, it is possible to prevent a foreign substance existing outside the first electrode from entering and short-circuiting the first electrode and the second electrode.

  According to the present invention (Claim 5), when the pressure in the accommodation space increases, the seal member is deformed and separated from the connection member, and the pressure increase in the internal space can be suppressed. On the other hand, when a foreign substance tries to enter the opening, the seal member is pressed against the connection member. Therefore, it can prevent that a foreign material penetrate | invades from the outside and a 1st electrode and a 2nd electrode short-circuit.

  According to the present invention (Claim 6), the gas discharged from the housing space of the first electrode can be stored in the space formed inside the seal member.

  According to the present invention (Claim 7), the insulating member that electrically cuts off the first electrode and the conductive member also serves as a seal member that prevents a short circuit between the first electrode and the second electrode. Therefore, it is not necessary to provide a dedicated seal member, and the increase in the number of parts of the battery cell can be suppressed.

  According to the present invention (claims 8 and 9), the first electrode is not exposed, and a short circuit between the first electrode and the second electrode can be prevented.

  According to the present invention (Claim 10), water does not permeate into the seal member, and a short circuit between the first electrode and the second electrode can be reliably prevented.

  According to the present invention (claim 11), since the sealing member is provided, even if a foreign substance enters the housing case, it is possible to prevent the first electrode and the second electrode from being short-circuited.

  According to the present invention (Claim 12), when a foreign matter outside the storage case enters the storage case via the terminal insertion hole with the battery pack attached to the electric tool, It is possible to prevent a short circuit between the second elastic pole.

  According to the present invention (Claim 13), since the sealing member is attached to the opening of the first electrode, the positional relationship between the battery cell and the connection member in the direction perpendicular to the center line of the battery cell. Regardless, the seal member can seal between the opening and the connection member.

  According to the present invention (Claim 14), since the sealing member is attached to the connecting member of the battery pack, when the second electrode of the battery cell is brought into contact with the connecting member, the opening is formed regardless of the structure of the battery cell. Can be sealed.

  According to the present invention (Claim 15), when the second electrode of the battery cell contacts the connecting member of the battery pack, the sealing member contacts the connecting member, and the sealing member connects the opening of the first electrode and the outside. Cut off. Therefore, no special operation is required to bring the seal member into contact with the connecting member.

  According to the present invention (Claim 16), the insulating member that electrically cuts off the first electrode and the conductive member also serves as a seal member that prevents a short circuit between the first electrode and the second electrode. Therefore, there is no need to provide a dedicated seal member, and an increase in the number of parts of the battery pack can be suppressed.

  According to the present invention (Claim 17), when the pressure in the housing space rises with the battery cell housed in the housing case, the seal member is deformed and separated from the connecting member, thereby suppressing the pressure rise in the internal space. it can. On the other hand, when a foreign substance tries to enter the opening, the seal member is pressed against the connection member. Therefore, it is possible to prevent foreign matters outside the storage case from entering the storage case and short-circuiting the first electrode and the second electrode.

  According to the present invention (invention 18), the gas discharged from the storage space of the first electrode can be stored in the space formed inside the seal member.

  According to the present invention (Claim 19), since the urethane is applied from the blocking member to the outer surface of the first electrode to improve the sealing performance, the foreign matter outside the first electrode It can prevent more reliably that a 2nd electrode short-circuits.

  According to the present invention (claim 20), it is possible to prevent foreign matter outside the storage case from entering the storage case and short-circuiting the first electrode and the second electrode of the battery cell.

It is a conceptual diagram which shows the state before attaching the battery pack of this invention to an electric tool. It is a perspective view which shows the external appearance of the battery pack of this invention. It is the perspective view which decomposed | disassembled the battery pack of this invention. It is a fragmentary sectional view showing the battery cell of the 1st example of the present invention. It is a partial side view which shows the battery cell of 1st Example of this invention. It is a fragmentary sectional view showing a battery cell of the 2nd example of the present invention. It is a fragmentary sectional view showing a battery cell of the 3rd example of the present invention. It is a fragmentary sectional view showing a battery cell of the 4th example of the present invention. It is a fragmentary sectional view showing the battery cell of the 5th example of the present invention. It is sectional drawing which shows the conventional battery cell.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, a schematic configuration of the electric power tool of the present invention will be described with reference to FIG. The electric tool 10 includes a main body portion 10a in which an electric motor (not shown) is accommodated, a grip portion 10b that is continuous with the main body portion 10a and is gripped by an operator, and a main body portion 10a in the grip portion 10b. And a cassette portion 10c provided at the opposite end. The cassette portion 10c has a recess 10d, and a plurality of tool side terminals 11 are provided in the recess 10d. The plurality of tool-side terminals 11 are connected to a circuit board (not shown) that controls the electric motor. The electric power tool 10 can attach and detach the battery pack 12 with respect to the cassette portion 10c.

  Next, the structure of the battery pack 12 of this invention is demonstrated based on FIG.2 and FIG.3. The battery pack 12 includes a plurality of battery cells 13, a holder 14 that holds the plurality of battery cells 13, and a housing case 15 that houses the holder 14 that holds the plurality of battery cells 13. The housing case 15 includes a case body 16 and a cover 17 that closes the opening 16 a of the case body 16. The holder 14, the case main body 16 and the cover 17 are each configured separately from a non-conductive material, for example, a resin material. The holder 14 is configured in a cylindrical shape so as to hold a plurality of battery cells 13, specifically, eight battery cells 13 in parallel with each other. Openings are provided on both sides of the holder 14, and the electrodes of the battery cells 13 are disposed in the openings.

  In addition, a connection plate (described later) for connecting the electrodes of the plurality of battery cells 13 is attached to the holder 14. The connection plate includes a connection plate that connects the positive electrodes, a connection plate that connects the negative electrodes, and a connection plate that connects the negative electrode and the positive electrode in series. An insulating member 18 is attached so as to overlap the connecting plate. The insulating member 18 has a plate shape. A circuit board 19 is fixed to the outside of the holder 14. An electric circuit is formed on the circuit board 19. A plurality of pack-side terminals 20 are attached to the circuit board 19. The plurality of pack side terminals 20 include a positive side terminal and a negative side terminal. The positive electrode side terminal is connected to a connection plate connecting the positive electrodes. The negative electrode side terminal is connected to a connection plate connecting the negative electrodes. Said connection board is comprised with the electroconductive metal material, for example, the material by which the surface of the rolled steel plate was nickel-plated.

  The cover 17 is provided with a plurality of terminal insertion holes 17a. The plurality of terminal insertion holes 17 a communicate the inside and the outside of the housing case 15. When the holder 14 holding the battery cell 13 is accommodated in the case body 16 and the opening 16a of the case body 16 is closed by the cover 17, the plurality of pack-side terminals 20 are inserted into the plurality of terminal insertion holes 17a. Each is inserted separately. Examples of the battery cells 13 housed in the battery pack 12 will be sequentially described.

(First embodiment)
The configuration of the battery cell 13 corresponding to the first embodiment of the present invention will be described with reference to FIGS. The battery cell 13 is a sealed secondary battery that can be repeatedly charged and discharged, and the battery cell 13 includes a battery can 21. The battery can 21 is formed by pressing a metal material such as a steel plate or stainless steel whose surface is nickel-plated into a bottomed cylindrical shape. The battery can 21 has a barrel portion 21a formed so as to surround the center line C, an annular holding portion 21b, and a constricted portion 21c in which the barrel portion 21a and the holding portion 21b are continuous. Further, a flange 21f is formed at the end of the holding portion 21b opposite to the constricted portion 21c. The flange 21f extends inward in the diametrical direction centered on the center line C. The flange 21f is provided over the entire circumference of the battery can 21, and an opening 21e of the battery can 21 is formed by the flange 21f. Thus, the accommodation space 22 is formed inside the battery can 21, and the battery can 21 constitutes a negative electrode as an electrode of the battery cell 13. In the housing space 22 of the battery can 21, an electrode body 23 and a non-aqueous electrolyte (not shown) are housed (provided).

  The electrode body 23 is formed by winding a sheet-like positive electrode plate and a negative electrode plate in a spiral shape in a state of being laminated in the thickness direction via a separator. The positive electrode plate has a positive electrode active material, while the negative electrode plate has a negative electrode active material and is configured to be chargeable / dischargeable. The negative electrode plate is electrically connected to the bottom 21d of the battery can 21 by a negative electrode tab (not shown). A well-known thing can be used for the positive electrode active material used as a positive electrode plate, and the negative electrode active material used as a negative electrode plate.

  A cap 24, a metal ring 25, a cleavage vent (cleavage valve) 26, and a current interruption vent (interruption valve) 27 are provided near the opening 21 e in the accommodation space 22 of the battery can 21. That is, a cap 24, a metal ring 25, a cleavage vent 26, and a current interruption vent 27 are attached to the inside of the holding portion 21b in the diameter direction of the battery can 21. The cap 24 is an element that functions as an electrode (positive electrode) of the battery cell 13. That is, the battery cell 13 includes the battery can 21 and the cap 24 as two electrodes having different polarities. The current interruption vent 27, the cleavage vent 26, and the metal ring 25 are elements that constitute a current path between the electrode body 23 and the cap 24.

  The current interrupting vent 27 is formed in a disk shape by press-molding a conductive metal material, for example, aluminum. The current interruption vent 27 is interposed between the cleavage vent 26 and the electrode body 23 in the direction of current flow. The current interruption vent 27 has a disk-shaped main body portion 27a, a cylindrical portion 27b, and a flange 27c. The cylindrical portion 27b is continuous with the outer peripheral end of the main body portion 27a and extends in a direction along the trunk portion 21a, specifically toward the outside of the battery can 21. The flange 27 c is formed continuously at the end of the cylindrical portion 27 b and extends inward in the diameter direction of the battery can 21. The outer diameter of the current interruption vent 27 is larger than the inner diameter of the constricted portion 21c and smaller than the inner diameter of the holding portion 21b. The main body 27a of the current interruption vent 27 is provided with a vent hole 27d penetrating in the thickness direction.

  Further, a seal member 29 is interposed between the battery can 21 and the current interruption vent 27. The seal member 29 is integrally formed of an insulating rubber-like elastic body. The seal member 29 has a cylindrical portion 29a, a first flange 29b, and a second flange 29c. The first flange 29b extends inward from one end in a direction along the center line (not shown) of the cylindrical portion 29a. The second flange 29c extends inward from the other end in the direction along the center line of the cylindrical portion 29a. That is, the sealing member 29 has a U-shaped cross-section in a plane including the center line C of the battery can 21. The first flange 29 b of the seal member 29 is in contact with the main body portion 27 a of the current interruption vent 27. The cylindrical portion 29a is in contact with the cylindrical portion 27b, and the second flange 29c is fixed in a state of being in contact with the flange 27c. Further, the seal member 29 is fixed in a state of being in contact with the constricted portion 21c and the holding portion 21b of the battery can 21. The seal member 29 functions as a gasket that seals between the current interrupt vent 27 and the battery can 21 while being fixed between the current interrupt vent 27 and the battery can 21. The sealing member 29 has a function as a blocking member (insulating member) that electrically blocks the current blocking vent 27 and the battery can 21.

  The cleavage vent 26 is formed by pressing a conductive metal material such as aluminum into a disk shape. The cleavage vent 26 is disposed between the metal ring 25 and the current interruption vent 27 in the direction of current flow. Further, a protruding portion 26 a that protrudes toward the main body portion 27 a is formed at the center of the cleavage vent 26. And the protrusion part 26a is welded with the center of the main-body part 27a, and the welding part 28 is formed. The welding portion 28 electrically connects the current interruption vent 27 and the cleavage vent 26. Further, the fragile portion 26b whose strength in the thickness direction is weakened is formed in the cleavage vent 26. The fragile portion 26b is obtained by providing a groove in the cleavage vent 26. The fragile portion 26b is formed in an annular shape on the outer peripheral side of the protruding portion 26a.

  The metal ring 25 is disposed between the cap 24 and the cleavage vent 26 in the direction of current flow. The metal ring 25 is configured, for example, by sandwiching a conductive polymer between two metal electrode foils. The metal ring 25 has a characteristic that current flow resistance increases as the temperature of the accommodation space 22 of the battery can 21 increases. The metal ring 25 is in contact with the outer peripheral side of the fragile portion 26 b in the cleavage vent 26, and a hole 25 a is provided in the center of the metal ring 25.

  The cap 24 is made of a conductive metal material, for example, a material obtained by applying nickel plating to the surface of a rolled steel plate. The cap 24 has a disk-shaped main body 24a, a cylindrical portion 24b provided continuously on the outer periphery of the main body 24a, and a flange 24c provided continuously on one end of the cylindrical portion 24b. . The flange 24c extends outward in the diameter direction. The flange 24c is provided over the entire circumference of the cylindrical portion 24b. A vent hole 24d that penetrates the cylindrical portion 24b in the radial direction is provided. A metal ring 25 is sandwiched between the flange 24 c and the cleavage vent 26. The cylindrical portion 24b is inserted into the opening 21e, and the cylindrical portion 24b extends from the inside of the holding portion 21b toward the outside of the battery can 21. The main body 24a is located outside the opening 21e. The inner diameter of the flange 21f is smaller than the outer diameter of the flange 24c of the cap 24, the outer diameter of the metal ring 25, the outer diameter of the cleavage vent 26, and larger than the outer diameter of the cylindrical portion 24b of the cap 24. The outer diameter of the cylindrical portion 24b is smaller than the inner diameter of the flange 27c and the inner diameters of the second flanges 29c and 30c. The cylindrical portion 24b is inserted into the flange 27c and the second flanges 29c and 30c.

  Further, a seal member 30 is provided so as to surround the outer peripheral side of the cleavage vent 26, the outer peripheral side of the metal ring 25, and the outer peripheral side of the flange 24 c of the cap 24. The seal member 30 is integrally formed of an insulating material, for example, a rubber-like elastic body. The seal member 30 includes a cylindrical portion 30a, a first flange 30b, and a second flange 30c. The first flange 30b extends inward from one end in a direction along a center line (not shown) of the cylindrical portion 30a. The second flange 30c extends inward from the other end in a direction along the center line of the cylindrical portion 30a. The seal member 30 is fixed in a state where the cylindrical portion 30a is in contact with the outer peripheral end of the cleavage vent 26, the outer peripheral end of the metal ring 25, the outer peripheral end of the flange 24c of the cap 24, and in contact with the cylindrical portion 27b. . The seal member 30 is fixed in a state in which the first flange 30 b is in contact with the main body portion 27 a and the cleavage vent 26 of the current interrupting vent 27. The seal member 30 is fixed in a state where the second flange 30c is in contact with the flange 27c and the flange 24c.

  The seal member 30 functions as a gasket that seals between the current interrupting vent 27 and the cap 24, the cleavage vent 26, and the metal ring 25 in a fixed state. Further, the seal member 30 functions as a blocking member (insulating member) for preventing the current blocking vent 27 and the metal ring 25 from short-circuiting directly, and the current blocking vent 27 and the cap 24 are directly short-circuited. And a function as a blocking member (insulating member) for preventing the above.

  Furthermore, the outer peripheral surface of the battery can 21 is covered with a cylindrical tube 31 integrally formed of an insulating material. As the insulating material of the tube 31, polyethylene or the like can be used. The tube 31 has a cylindrical body portion 31c and a cylindrical portion 31d. The body portion 31 c covers the outer peripheral surface of the body portion 21 a of the battery can 21. The tube 31 has a constricted portion 31e that connects the body portion 31c and the cylindrical portion 31d. The constricted portion 31 e covers the outer surface of the constricted portion 21 c of the battery can 21. Furthermore, the tube 31 has an inward flange 31f that is continuous with an end portion of the cylindrical portion 31d opposite to the constricted portion 31e. The flange 31f covers the surface of the flange 21f. An opening 31a is formed inside the flange 31f, and an opening 31b is formed on the opposite side to the constricted portion 31e in the body portion 31c. The bottom 21d of the battery can 21 is exposed at the opening 31b. Moreover, the internal diameter of the opening part 31a is substantially the same as the internal diameter of the opening part 21e, and the cylindrical part 24b is arrange | positioned in the opening part 31a. Therefore, a part of the cylindrical portion 24b and the main body portion 24a are disposed outside the battery can 21 through the opening 31a.

  The battery cell 13 in the present embodiment includes a seal member 32 that prevents two electrodes having different polarities, that is, the battery can 21 and the cap 24 from being short-circuited. The seal member 32 is fixed to an end portion in the direction along the center line C of the battery can 21, specifically, to the flange 31 f. The seal member 32 is an annular body having a hole 32a at the center and disposed coaxially with the center line C. The seal member 32 is formed in an annular body along the opening 21e. The seal member 32 is fixed to the flange 31f of the tube 31 using a double-sided adhesive tape or an adhesive. That is, the seal member 32 is indirectly attached to the flange 21f of the battery can 21 with the tube 31 interposed. The outer diameter of the seal member 32 is substantially the same as the outer diameter of the tube 31, and the inner diameter of the hole 32 a is larger than the outer diameter of the cylindrical portion 24 b of the cap 24. The seal member 32 is integrally formed of a material such as silicone rubber (VMQ, FVMQ), ethylene / propylene rubber (EPM, EPDM), chloroprene rubber (CR), and has water repellency.

  In the state where the battery cell 13 is not stored in the holder 14, the sealing member 32 has a protruding amount from the opening end of the tube 31 larger than a protruding amount of the cap 24 from the opening end of the tube 31. When the battery cell 13 is stored in the holder 14, the seal member 32 is pressed against the connection plate 33 and elastically deformed. Further, the main body 24 a of the cap 24 contacts the connection plate 33. The sealing member 32 is pressed against the connection plate 33 to form an annular sealing surface. In this way, the space A including the contact portion between the main body 24 a of the cap 24 and the connection plate 33 is sealed by the seal member 32. That is, the seal member 32 has a function of blocking the space A and the outside B of the battery can 21. The space A is annularly formed coaxially with the center line C between the connection plate 33 and the flange 24c.

  In the battery pack 12, for example, the caps 24 of the two battery cells 13 and the bottom portions 21 d of the other two battery cells 13 are stored in a state where they are connected in series to the same connection plate 33. When the battery pack 12 containing the battery cells 13 is attached to the cassette portion 10c, the plurality of tool-side terminals 11 and the plurality of pack-side terminals 20 are connected to supply the electric power of the plurality of battery cells 13 to the electric motor. It will be possible to do. The battery pack 12 is removed from the cassette portion 10c, the battery pack 12 is mounted on a charger (not shown), a direct current is generated using a commercial power source such as an alternating current 100V, and the electric power is supplied to the battery cell 13 Can be charged. When the battery cell 13 is discharged or charged, a current flows between the electrode body 23 and the cap 24 in the battery cell 13.

  When the battery cell 13 is discharged, current flows to the cap 24 via the current interrupt vent 27, the cleavage vent 26, and the metal ring 25. The current that flows to the cap 24 flows to the pack-side terminal 20 via the connection plate 33. On the other hand, when the battery cell 13 is charged, the current of the charger flows to the cap 24 via the pack side terminal 20 and the connection plate 33, and further, the current flows via the metal ring 25 and the cleavage vent 26. It flows into the blocking vent 27.

  In the present embodiment, the seal member 32 is connected to the connecting plate 33 in either the state where the battery pack 12 is mounted on the cassette portion 10c of the electric tool 10 or the state where the battery pack 12 is removed from the electric tool 10. And a sealing surface is formed. For this reason, even if the battery pack 12 is flooded, the water does not enter the space A from the contact portion between the sealing member 32 and the connection plate 33. Therefore, in the space A, the battery can 21 and the cap 24 can be prevented from being short-circuited, and the leakage of the battery cell 13 and the failure of the battery cell 13 can be prevented. Furthermore, since the sealing member 32 has water repellency, water does not penetrate into the sealing member 32, and a short circuit between the battery can 21 and the cap 24 can be reliably prevented. That is, the sealing member 32 can prevent permeation leakage. Further, since the seal member 32 is disposed away from the cap 24, even if water soaks into the seal member 32, a short circuit between the cap 24 and the battery can 21 can be prevented.

  Further, the sealing member 32 is attached to the battery can 21 of the battery cell 13. For this reason, when the cap 24 comes into contact with the connection plate 33, the sealing member 32 is connected to the connection plate regardless of the positional relationship between the battery cell 13 and the connection plate 33 in a plane perpendicular to the center line C of the battery can 21. 33 and the outside B of the battery can 21 and the opening 21e can be shut off.

  Furthermore, when the temperature of the housing space 22 of the battery can 21 becomes equal to or higher than a predetermined temperature, the resistance value of the metal ring 25 increases, and current flowing between the cleavage vent 26 and the cap 24 is suppressed. Further, the seal member 29 prevents the electrolyte in the accommodation space 22 from leaking between the battery can 21 and the current interrupt vent 27. Further, the seal member 30 prevents the electrolytic solution in the accommodation space 22 from leaking between the current interruption vent 27 and the cleavage vent 26.

  Further, when the pressure of the storage space 22 of the battery can 21 increases due to overcharge or the like, the battery cell 13 is applied to the cleavage vent 26 through the vent hole 27d of the current interruption vent 27. Then, the cleavage vent 26 is pressed toward the cap 24, and the current interruption vent 27 connected to the cleavage vent 26 via the welded portion 28 is also pulled. When the pressure in the housing space 22 of the battery can 21 further increases, the fragile portion 26b of the cleavage vent 26 is broken. Then, the gas in the storage space 22 of the battery can 21 reaches between the cap 24 and the cleavage vent 26 via the broken portion, and further, the gas is discharged to the space A via the vent hole 24d. . By this action, the pressure of the housing space 22 of the battery can 21 can be reduced, and the battery can 21 can be prevented from bursting.

(Second embodiment)
Next, the configuration of the battery cell 13 corresponding to the second embodiment of the present invention will be described with reference to FIG. 6, the same components as those in FIGS. 4 and 5 are denoted by the same reference numerals as those in FIGS. The battery cell 13 shown in FIG. 6 has a seal member 34. The seal member 34 is formed by annularly molding a rubber-like elastic body, and the seal member 34 has a hole 34a at the center. The inner diameter of the hole 34 a is larger than the outer diameter of the cylindrical portion 24 b of the cap 24. The inner peripheral side of the seal member 34 is fixed to the flange 31 f of the tube 31. The inner peripheral side of the seal member 34 is fixed to the tube 31 with an adhesive or a double-sided tape. That is, the seal member 34 is formed in an annular shape along the opening 21 e and is indirectly attached to the battery can 21. The outer peripheral side of the sealing member 34, that is, the free end is in contact with the connection plate 33 in a state where the battery cell 13 is accommodated in the holder 14. The free end of the seal member 34 is pressed against the connection plate 33 by an elastic force, and an annular seal surface is formed at a contact portion between the seal member 34 and the connection plate 33. The seal member 34 has a taper that increases in diameter as it approaches the connection plate 33.

  The battery cell 13 of the second embodiment has the same operational effects as the battery cell 13 of the first embodiment with respect to the same components as the battery cell 13 of the first embodiment. Further, in the battery cell 13 of the second embodiment, even if the water outside the battery can 21 scatters toward the sealing member 34, the sealing member 34 blocks the water. Therefore, the seal member 34 can prevent water from entering the space A. Further, the seal member 34 of FIG. 6 has a taper that increases in diameter as it approaches the connection plate 33. For this reason, when the water pressure of the outside B of the battery can 21 rises, the force with which the sealing member 34 is pressed against the connection plate 33 is increased, and the sealing performance of the sealing member 34 is improved.

  Furthermore, the seal member 34 has a taper that increases in diameter as it approaches the connection plate 33. For this reason, when the gas in the storage space 22 of the battery can 21 is discharged to the space A via the vent hole 24d, the battery cell 13 has a two-dot chain line with the sealing member 34 facing outward due to the pressure of the gas. The seal member 34 is separated from the connection plate 33 and a gap is formed. Therefore, the gas in the space A is discharged to the outside B through a gap. As described above, the seal member 34 is pressed against the connection plate 33 as shown by the solid line in the direction in which water outside the battery can 21 enters the seal surface.

  On the other hand, when the pressure of the gas in the storage space 22 of the battery can 21 is applied to the seal member 34 in the direction of discharging from the space A to the outside B of the battery can 21, the seal member 34 is elastically deformed as indicated by a two-dot chain line. And away from the connection plate 33. That is, the seal member 34 has a check valve function. In the second embodiment, since the sealing member 34 is attached to the battery can 21, the positional relationship between the battery cell 13 and the connection plate 33 in a direction along a plane perpendicular to the center line C of the battery can 21. Regardless, the free end of the seal member 34 can be pressed against the connection plate 33, and the opening 21 e and the outside B can be blocked by the seal member 34. Further, the gas discharged from the accommodation space 22 to the space A is stored in the space A until the seal member 34 is deformed and separated from the connection plate 33. That is, the space A functions as a buffer that stores the gas discharged from the accommodation space 22 into the space A.

(Third embodiment)
Furthermore, the configuration of the battery cell 13 corresponding to the third embodiment of the present invention will be described with reference to FIG. The seal member 34 in FIG. 7 has the same configuration as the seal member 34 in FIG. When the configuration shown in FIG. 7 and the configuration of FIG. 6 are compared, the structure of the connection plate 33 is different. The connection plate 33 shown in FIG. 7 is provided with a protruding portion 33 a that protrudes away from the insulating member 18. The protrusion 33 a is in contact with the main body 24 a of the cap 24. The free end of the seal member 34 surrounds the periphery of the protrusion 33a to form an annular seal surface. The volume of the space A, which is a space between the battery cell 13 and the connection plate 33 and is sealed by the seal member 34, is larger than the volume of the space A shown in FIG. Specifically, the volume corresponding to the protruding height of the protruding portion 33a is wide.

  The other configuration of the battery cell 13 of FIG. 7 is the same as the configuration of the battery cell 13 of FIG. In the battery cell 13 of FIG. 7, the same effect as that of the battery cell 13 of FIG. Moreover, the volume of the space A in the battery cell 13 of FIG. 7 is larger than the volume of the space A of the battery cell 13 of FIG. For this reason, when the gas in the storage space 22 of the battery can 21 passes through the vent hole 24d of the cap 24 and is discharged into the space A, the seal member 34 is elastically deformed, and the connection plate 33 is shown as a two-dot chain line. It is possible to delay the time away from the battery cell 13 as compared with the battery cell 13 of FIG.

(Fourth embodiment)
The configuration of the battery cell 13 corresponding to the fourth embodiment of the present invention will be described with reference to FIG. The configuration of the battery cell 13 in FIG. 8 is substantially the same as the configuration of the battery cell 13 in FIG. The battery cell 13 of FIG. 8 is different in that the seal member 32 of FIG. 4 is not provided. The seal member 29 in FIG. 8 includes a folded portion 29d that is continuous with the second flange 29c and folded outward in the diametrical direction. The folded portion 29d is formed over the entire circumference at the inner circumferential end of the second flange 29c. That is, the folded portion 29d of the seal member 29 is configured in an annular shape along the opening 21e. And the front-end | tip of the flange 21f of the battery can 21 is pinched | interposed over the perimeter between the 2nd flange 29c and the folding | returning part 29d. The outer surface of the folded portion 29 d is covered with the flange 31 f of the tube 31. That is, the folded portion 29d and the flange 31f are in close contact with each other to form a seal surface. Further, the tube 31 and the folded portion 29d are connected, and the flange 21f is not exposed.

  When the battery cell 13 of FIG. 8 is accommodated in the holder 14 of the battery pack 12, the main body 24 a of the cap 24 contacts the connection plate 33. And the battery cell 13 of FIG. 8 can obtain the same effect as the battery cell 13 of FIG. 4 about the same component as the battery cell 13 of FIG. Further, in the battery cell 13 of FIG. 8, the flange 21f of the battery can 21 is sandwiched between the second flange 29c of the seal member 29 and the folded portion 29d. Further, the battery cell 13 forms a sealing surface by closely contacting the folded portion 29d and the flange 31f of the tube 31, and the flange 21f is not exposed. For this reason, the battery cell 13 prevents the cap 24 and the flange 21f of the battery can 21 from being short-circuited when water enters the cap 24 via the connection plate 33 and the flange 31f of the tube 31. it can.

(5th Example)
Furthermore, a fifth embodiment of the present invention will be described with reference to FIGS. The battery pack 12 accommodates eight battery cells 13. The battery pack 12 of FIG. 3 has a configuration in which four battery cells 13 arranged in the horizontal direction (horizontal direction) are arranged in one stage and the battery cells 13 are arranged in two stages in the vertical direction. The eight battery cells 13 accommodated in the battery pack 12 are all parallel at the center lines. In FIG. 9, for convenience, two battery cells 13 that are adjacent in the horizontal direction are shown with the cap 24 in the reverse direction. The cap 24 of one battery cell 13 and the bottom 21 d of the other battery cell 13 are connected in series by a connection plate 33. In the two battery cells 13 shown in FIG. 9, the portion including the connection portion between the cap 24 and the connection plate 33 is covered with urethane 35. Urethane 35 is a compound in which an amino group and an alcohol group are dehydrated and condensed via a carbonyl group. In addition, the urethane 35 in this invention includes what is conventionally called urethane, such as well ethyl carbamate and polyurethane (urethane resin).

  The urethane 35 is coated so as to cover the entire range from the body portion 31c and the cylindrical portion 31d of the tube 31 to the insulating member 18 in the direction along the center line C of the battery can 21. That is, the urethane 35 is coated so as to cover all the outer surfaces of the constricted portion 31 e and the cylindrical portion 31 d of the tube 31, the sealing member 32, the connection plate 33, and the insulating member 18. In the present invention, the method of coating the urethane 35 includes a method of covering the battery cells 13 one by one and a method of covering all eight cells at once. The urethane 35 is not coated on the body portion 31 c of the tube 31 at the center in the direction along the center line C of the battery cell 13.

  If the battery cell 13 accommodated in the battery pack 12 shown in FIG. 3 is coated with urethane 35 as shown in FIG. 9, the sealing performance of the battery cell 13 is further improved. Therefore, a short circuit between the battery cells 13 can be prevented, and leakage and a failure of the battery cell 13 can be prevented. Further, when the battery pack 12 is attached to the charger for charging, the battery pack 12 is cooled with cooling air. Here, since the urethane 35 is not applied to the center of the battery cell 13 in the direction along the center line C, the flow of the cooling air is not hindered by the urethane 35, and a decrease in cooling performance can be suppressed. Although not shown, if the circuit board 19 is covered with urethane, the circuit board 19 can be prevented from being immersed in water. Therefore, the waterproofing agent such as silicon applied to the circuit board 19 can be reduced, and an increase in manufacturing cost of the battery pack 12 can be suppressed. Furthermore, since urethane applied to the circuit board 19 can be easily peeled off from the circuit board 19, the recyclability of the circuit board 19 can be improved.

  Here, a correspondence relationship between the configuration described in the present embodiment and the configuration of the present invention will be described. The housing space 22 corresponds to “the inside of the first electrode” of the present invention, the battery can 21 corresponds to the first electrode of the present invention, and the opening 21 e corresponds to “the opening of the first electrode” of the present invention. The cap 24 corresponds to the second electrode of the present invention, and the outside B corresponds to “the outside of the first electrode” of the present invention. Further, the seal members 30, 32, and 34 correspond to the seal member of the present invention, the connection plate 33 corresponds to the connection member of the present invention, and the current interruption vent 27 corresponds to the conductive member of the present invention. The sealing member 30 corresponds to the “insulating member that also serves as the sealing member” of the present invention, the space A corresponds to “the space formed inside the sealing member” of the present invention, and the insulating member 18 The tube 31 corresponds to the blocking member of the present invention, and the tube 31 corresponds to the second insulating member of the present invention.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, the seal member of the present invention includes a porous body (sponge) in addition to a solid body made of a rubber-like elastic body, silicon or the like. The seal member of the battery pack of the present invention includes a seal member (not shown) attached to the positive electrode side connection plate in addition to the seal member 32 fixed to the tube 31 as shown in FIGS. The seal member attached to the positive electrode side connection plate is fixed to the positive electrode side connection plate using an adhesive or a double-sided tape. In the battery pack in which the sealing member is attached to the positive electrode side connection plate, the opening and the outside of the first electrode can be blocked by the sealing member if the battery cell is housed in the housing case regardless of the structure of the battery cell. . Moreover, the battery cell of this invention contains the battery cell whose battery can is a positive electrode terminal and a cap is a negative electrode terminal other than the battery cell whose battery can is a negative electrode terminal and a cap is a positive electrode terminal. Further, the battery can includes a bottomed cylindrical shape and a bottomed rectangular tube-shaped structure. Furthermore, the battery cell of the present invention includes a lithium ion battery cell, a nickel metal hydride battery cell, a lithium ion polymer battery cell, a nickel cadmium battery cell, and the like. Moreover, the foreign material which a sealing member and urethane of this invention prevent invasion, ie, the foreign material which exists outside the 1st electrode contains dust, mud, etc. other than water. Moreover, the battery pack of the present invention includes a structure in which a single battery cell is accommodated inside the accommodation case.

21 Battery can 21e Opening 22 Storage space 24 Cap 32 Seal member B External

Claims (20)

A battery cell having a first electrode having an opening communicating with a housing space, and a second electrode provided in the opening of the first electrode and having a polarity different from that of the first electrode,
A battery cell, comprising: a sealing member that prevents the first electrode and the second electrode from being short-circuited by a foreign matter that has entered from the outside of the first electrode.   The battery cell according to claim 1, wherein the seal member is disposed apart from the second electrode.   The seal member is configured in an annular shape along the opening, and is disposed between the first electrode and the connection member that connects the second electrode, and is disposed apart from the second electrode. The battery cell according to claim 1.   The seal member is configured annularly along the opening and attached to the first electrode, and the seal member is connected to the connection member of the battery pack when the second electrode is in contact with the connection member of the battery pack. The battery cell according to claim 1, wherein the battery cell is in contact with the first electrode to block the outside of the first electrode and the opening.   The seal member is deformed so as to be separated from the connection member when the pressure in the accommodation space of the first electrode increases, and is pressed against the connection member when the foreign matter tries to enter the opening. The battery cell according to claim 4.   When the seal member is brought into contact with the connecting member, a space formed inside the seal member functions as a buffer for storing gas discharged from the housing space of the first electrode. The battery cell according to claim 5.   An electrode body provided in the housing space of the first electrode and a conductive body provided in the housing space of the first electrode and forming a current path between the electrode body and the second electrode A member, and an insulating member that is interposed between the first electrode and the conductive member to electrically cut off the first electrode and the conductive member, and the insulating member also serves as the seal member The battery cell according to claim 1.   An electrode body provided in the housing space of the first electrode and a conductive body provided in the housing space of the first electrode and forming a current path between the electrode body and the second electrode A member, and an insulating member interposed between the first electrode and the conductive member to electrically cut off the first electrode and the conductive member, wherein the insulating member is an end of the first electrode. The battery cell according to claim 1, wherein the battery cell is configured to cover the portion.   The battery cell according to claim 8, wherein the insulating member is connected to a second insulating member that covers an outer periphery of the first electrode.   The battery cell according to claim 1, wherein the sealing member has water repellency. A battery cell having a first electrode having an opening communicating with a housing space, and a second electrode provided in the opening of the first electrode and having a polarity different from that of the first electrode;
A battery pack comprising a housing case for housing the battery cell therein,
A seal member is provided to prevent the first electrode and the second electrode from being short-circuited by foreign matter that has entered the housing case from the outside of the first electrode of the battery cell. Battery pack. A plurality of battery cells provided with a second electrode having a polarity different from that of the first electrode in the opening of the first electrode in which an opening communicating with the accommodation space is formed; and the first of the plurality of battery cells A connecting member that connects one electrode and the second electrode; and a housing case that houses the plurality of battery cells and the connecting member therein, and the housing case is configured to be attached to and detached from the power tool. Battery pack,
A pack-side terminal provided inside the housing case and connected to the connection member;
A terminal insertion hole provided in the housing case and communicating between the inside and the outside of the housing case, and into which the pack-side terminal is inserted;
A seal member that prevents the first electrode and the second electrode from being short-circuited by foreign matter that has entered from the outside of the first electrode of the battery cell;
The battery pack, wherein the pack-side terminal is connected to a tool-side terminal of the electric tool when the housing case is attached to the electric tool.   The battery pack according to claim 12, wherein the seal member is formed in an annular shape along the opening and is attached to the first electrode.   The battery pack according to claim 13, wherein the seal member is attached to the connection member.   The seal member is configured in an annular shape along the opening, and contacts the connection member when the second electrodes of the plurality of battery cells are in contact with the connection member, respectively. The battery pack according to claim 13, wherein the outside of the first electrode of the battery cell and the opening are blocked.   The plurality of battery cells are provided in the accommodation space of the first electrode, in the accommodation space of the first electrode, and between the electrode body and the second electrode. A conductive member that forms a current path on the first electrode, and an insulating member that is interposed between the first electrode and the conductive member to electrically cut off the first electrode and the conductive member. The battery pack according to claim 13, which also serves as the sealing member.   The seal member is deformed so as to be separated from the connection member when the pressure in the accommodation space of the first electrode increases, and is pressed against the connection member when the foreign matter tries to enter the opening. The battery pack according to claim 15, characterized in that:   When the seal member is brought into contact with the connecting member, a space formed inside the seal member functions as a buffer for storing gas discharged from the housing space of the first electrode. The battery pack according to claim 17.   The blocking member has a blocking member that is in contact with a portion of the connecting member that is opposite to the portion that contacts the first electrode, and the sealing member and the connecting member are in a direction along the center line of the first electrode Urethane is applied across the outer surface of the first electrode from the blocking member in a direction along the center line, and disposed between the blocking member and the first electrode, and the sealing member and The battery pack according to claim 12, 14 or 16, wherein an outer side of the connection member is covered. An electric tool equipped with an electric motor,
The battery pack according to any one of claims 11 to 19, wherein the battery pack can be attached and detached, has a tool side terminal electrically connected to the electric motor, and the pack side terminal when the battery pack is attached. And the tool-side terminal are connected to each other.

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