JP2011222459A - Battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance safety by decreasing heat transfer to a casing of a battery pack.SOLUTION: A battery pack is equipped with a battery holder 70 that can hold multiple chargeable secondary batteries 39, a battery lead plate 80 that mutually connects the secondary batteries 39 at the end surfaces, a pack substrate 74 incorporating a protection circuit for the secondary batteries 39 and a casing 31 that accommodates the battery holder 70 and the pack substrate 74. The battery lead plate 80 is fixed to and exposed on the end surface of the battery holder 70, part of the surface of the battery holder 70 that contacts the casing 31 is corrugated and multiple irregularities 78 are created on that part. As a result, a layer of air is created in space created by the corrugation between the inner surface of the casing and the battery lead plate exposed outside the battery holder, and the layer of air improves insulation, decreases heating of the battery pack and makes it easier for a user to touch the battery pack by hand.

Description

  The present invention relates to a battery pack that is detachably attached to an electric device such as an electric tool and supplies electric power.

  Electrical devices such as electric tools can be conveniently used as a cordless system at a construction site or the like by detachably attaching a battery pack containing a rechargeable battery. Moreover, by removing the battery pack from the electric device, the removed battery pack can be charged and used repeatedly. The battery pack whose remaining battery capacity is reduced is set in a charger and charged. As a charger for charging such a battery pack, a charger having a mounting portion for detachably mounting the battery pack on the upper surface of the case and having a charging terminal exposed on the mounting portion has been put into practical use. Yes. This charger connects the external terminal of the battery pack attached to the attachment part to the charging terminal, and outputs charging power from the charging terminal to charge the battery pack (see Patent Document 1).

JP 2007-280679 A

  In the battery pack, rechargeable secondary battery cells are connected by lead plates and stored in an insulating casing. When the battery pack is connected to an electrical device and discharged, a large current flows through the lead plate, and the lead plate may generate heat. In general, a battery pack has a shape that almost conforms to the outer shape of a secondary battery cell due to a demand for miniaturization. As a result, the end face of the secondary battery cell faces the casing of the battery pack, and the end face of the secondary battery cell is connected with the lead plate, so that the lead plate is also arranged in a posture facing the casing. Become. As a result, the lead plate comes into contact with the inner surface of the casing, and the heat generated in the lead plate is thermally transferred to the casing, resulting in a situation where the casing has heat. In such a case, it is conceivable that the user touches the casing of the battery pack, for example, to replace the battery pack. Therefore, it is not preferable that the casing has heat.

  The present invention has been made in view of such a background, and a main object of the present invention is to provide a battery pack having improved safety by reducing heat conduction to the casing of the battery pack.

Means for Solving the Problems and Effects of the Invention

  In order to achieve the above object, the battery pack according to the first aspect of the present invention is a battery pack including a rechargeable secondary battery 39, and holds a plurality of rechargeable secondary batteries 39. A battery holder 70 to be connected, a battery lead plate 80 for connecting the secondary batteries 39 to each other at an end face, a pack board 74 on which a protection circuit for the secondary battery 39 is mounted, and the battery holder 70 and the pack board 74 are accommodated. The battery holder 70 is exposed in a posture in which the battery lead plate 80 is held, and a plurality of concave and convex stripes 78 are provided on the contact surface between the battery holder 70 and the casing 31. be able to. This provides an air layer that is partially separated between the battery lead plate exposed on the outer surface of the battery holder and the inner surface of the casing due to the unevenness of the ridges, improves heat insulation, and reduces heating of the battery pack Thus, the user can easily touch the casing by hand.

  Further, according to the battery pack according to the second aspect, the battery holder 70 forms an exposed portion 71 for exposing the battery lead plate 80 at its end face, and the battery lead plate 80 is A gap may be provided between the battery lead plate 80 disposed in the exposed portion 71 and the inner surface of the casing 31 while being disposed in the exposed portion 71. As a result, even if the battery lead plate generates heat due to the discharge of the secondary battery, the lead air layer can be interposed without being in direct contact with the casing by the gap, and the outside of the casing is heated by the heat of the battery lead plate Can be reduced. Further, it is possible to connect the battery lead plate by spot welding or the like from the side of the exposed portion.

  Furthermore, the battery pack according to the third aspect further includes a lead wire for wiring the battery lead plate 80 and the pack substrate 74, and guides the lead wire to the upper surface of the battery holder 70. A guide boss 76 can be provided. Accordingly, the lead wire can be held in a desired posture with a simple structure without separately providing a member for fixing the lead wire, and a so-called situation in which the lead wire becomes free in the casing after assembly can be avoided.

  Furthermore, the battery pack according to the fourth aspect further includes an output lead plate 82 for wiring the secondary battery 39 and the pack substrate 74, and a substrate lead plate connected to the pack substrate 74. One of the board lead plate and the output lead plate 82 is partially cut, and is bent at the cut portion to form a V-shaped gap. The other lead plate is sandwiched between the two, and the sandwiched portion can be soldered. As a result, it is possible to obtain an excellent advantage that it is possible to easily fix the lead plates by soldering, which was not easy in the past. In particular, a special member or structure for temporarily fixing the lead plates can be dispensed with, and the lead plates can be fixed in the minimum necessary space.

  Furthermore, according to the battery pack of the fifth aspect, the board lead plate can also serve as the external connection terminal 33 for connecting to a charging terminal of a charger for charging the battery pack. Thereby, soldering with a charge terminal and an output lead board can be performed easily.

  Furthermore, according to the battery pack of the sixth aspect, the external connection terminal 33 can be connected to the secondary battery 39 by the output lead plate 82 and the output lead wire 83. As a result, the combination of the lead plate and the lead wire enables efficient wiring with the secondary battery within the limited space available in the casing.

  Furthermore, according to the battery pack of the seventh aspect, the secondary battery 39 is a cylindrical battery extended in the longitudinal direction, and the plurality of cylindrical batteries are arranged adjacent to each other in parallel. The battery lead plate 80 forms a lead fixing portion 81 for fixing the lead wire, and the battery lead plate 80 is formed in the valley portion between adjacent cylindrical secondary batteries 39. The lead fixing portion 81 can be fixed to the end surface of the secondary battery 39 in a state where the lead fixing portion 81 is located. This makes it very easy to insert the lead wire into the lead fixing part of the battery lead plate by guiding the lead wire into the valley between adjacent cylindrical secondary batteries, saving labor in the assembly of the lead wire. Benefits that can be obtained.

  Furthermore, the battery pack according to the eighth aspect further includes temperature detecting means 54 for detecting the temperature of the secondary battery 39, and the temperature detecting means 54 is provided in the casing 31. Among the plurality of secondary batteries 39 arranged side by side, they can be arranged between the secondary batteries 39 positioned in the middle. Thereby, the temperature of the intermediate part in which the temperature tends to be high in the configuration in which the secondary batteries are arranged can be detected, and the secondary battery can be protected.

  Furthermore, according to the battery pack of the ninth aspect, the temperature detecting means 54 is connected to the pack substrate 74 via the signal lead wire 84, and the battery holder 70 is connected to the signal lead wire 84. A temperature detection insertion hole 55 through which the temperature detection insertion hole 55 passes is opened, and the pack substrate 74 can be fixed on the upper surface of the battery holder 70 at a position where the temperature detection insertion hole 55 is opened. As a result, the electrical connection between the temperature detection means and the pack substrate can be suppressed to a short distance, and the temperature detection insertion hole can be blocked by the pack substrate, and foreign matter can enter from the temperature detection insertion hole opened in the battery holder. Can be avoided.

1 is a perspective view showing a battery pack 100. FIG. It is the perspective view which looked at the battery pack of FIG. 1 from the back. It is a disassembled perspective view of the battery pack of FIG. It is the disassembled perspective view which looked at the battery pack of FIG. 3 from the back surface. It is a top view of the battery holder of FIG. It is a perspective view which shows the state before soldering of the battery holder of FIG. It is the perspective view which looked at the battery holder of FIG. 6 from the back. It is a disassembled perspective view of the battery holder of FIG. It is the perspective view which looked at FIG. 8 from the downward direction. It is a horizontal sectional view of a battery holder. It is a principal part expansion disassembled perspective view which shows the state which fixes a battery lead board to a secondary battery end surface. It is an expansion perspective view which shows the state which inserts a lead wire in the battery lead board of FIG. It is a perspective view which shows an external connection terminal. It is an expansion perspective view which shows the state which fixes an output lead board to the board | substrate lead board of FIG. It is a perspective view which shows the state which mounted | wore the battery pack charger with the battery pack. It is a perspective view which shows the state which removed the battery pack from the battery pack charger of FIG. It is the longitudinal cross-sectional view in the XVII-XVII line of the battery pack charger of FIG. It is a longitudinal cross-sectional view which shows the state which removed the battery pack from the battery pack charger of FIG. It is a cross-sectional view in the XIX-XIX line of FIG. It is a circuit diagram which shows the state which connected the battery pack to the charger concerning one Example of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiment described below exemplifies a battery pack for embodying the technical idea of the present invention, and the present invention does not specify the battery pack as follows. In addition, the member shown by the claim is not what specifies the member of embodiment. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the constituent members described in the embodiments are not intended to limit the scope of the present invention only to the description unless otherwise specified. It's just an example. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation. Furthermore, in the following description, the same name and symbol indicate the same or the same members, and detailed description thereof will be omitted as appropriate. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and the plurality of elements are shared by one member, and conversely, the function of one member is constituted by a plurality of members. It can also be realized by sharing. In addition, the contents described in some examples and embodiments may be used in other examples and embodiments.

1 to 14 show a battery pack according to an embodiment of the present invention. In these drawings, FIG. 1 is a perspective view showing the battery pack 30, FIG. 2 is a perspective view of the battery pack 30 of FIG. 1 viewed from the back, FIG. 3 is an exploded perspective view of the battery pack 30 of FIG. 3 is an exploded perspective view of the battery pack 30 as viewed from the back, FIG. 5 is a plan view of the battery holder 70 of FIG. 3, FIG. 6 is a perspective view showing a state before soldering of the battery holder 70 of FIG. FIG. 8 is an exploded perspective view of the battery holder 70 of FIG. 6, FIG. 9 is a perspective view of FIG. 8 viewed from below, and FIG. 10 is a horizontal view of the battery holder 70. FIG. 11 is an enlarged exploded perspective view of a main part showing a state in which the battery lead plate 80 is fixed to the end face of the secondary battery 39, and FIG. 12 is an enlarged perspective view showing a state in which lead wires are inserted into the battery lead plate 80 of FIG. 13 is a perspective view showing the external connection terminal 33, and FIG. An enlarged perspective view showing a state of fixing the power lead plate 82, respectively. In this example, an example in which the battery pack 30 is applied to a power tool will be described as an electrical device to which the battery pack 30 is attached. The battery pack 30 shown in these drawings includes a battery holder 70 that holds a plurality of rechargeable secondary batteries 39, a battery lead plate 80 that connects the secondary batteries 39 to each other at their end faces, and a protection circuit for the secondary battery 39. , A temperature detection means 54 for detecting the temperature of the secondary battery 39, and a casing 31 for storing the battery holder 70 and the pack substrate 74.
(Casing 31)

  As shown in FIGS. 1 and 2, the casing 31 is formed in a box shape and chamfers corners, and is connected to a power tool that is an electric device or a connection terminal 3 of a charger on the surface. External electrodes are exposed. Further, when the battery pack 30 is attached to an electric tool or a charger, a holding convex portion 37 is provided for holding the attachment state. The casing 31 is molded from a resin having excellent insulating properties and strength.

The casing 31 is divided into an upper casing 31A and a lower casing 31B as shown in the exploded perspective views of FIGS. A storage space is formed inside the casing 31, and the battery holder 70, the pack substrate 74, and the holding projection 37 are stored therein.
(Battery holder 70)

As shown in FIGS. 5, 6, and 7, the battery holder 70 includes a secondary battery 39, a pack substrate 74, a battery lead plate 80, and various lead wires. Further, as shown in the exploded perspective view of FIG. 8, the battery holder 70 is provided with a battery housing space for housing the secondary battery 39 on the lower surface and a substrate fixing portion 75 for fixing the pack substrate 74 on the upper surface. In the secondary batteries 39, the end faces of the secondary battery 39 exposed from the exposed portion 71 opened in the end face of the battery holder 70 are electrically connected by the battery lead plate 80, and the secondary battery 39 is further connected to the battery holder 70. The output of the battery core that houses the battery is connected to the pack substrate 74 by the output lead plate 82, the second output lead plate 82B, and the output lead wire 83. Further, the battery lead plate 80 is connected to the pack substrate 74 via a signal lead wire 84. Since the output lead 83 is a high-voltage wire, a thick conductor corresponding to a high current is used. On the other hand, since the signal lead 84 is a signal line, a thinner conductor is sufficient.
(Charge / discharge terminal 34)

The pack substrate 74 includes a charge / discharge terminal 34 for connecting the output of the battery core to an electric tool or a charger. In this example, the output from the battery core is connected to the charge / discharge terminal 34 on the pack substrate 74 via the second output lead plate 82B, the output lead wire 83, and the output lead plate 82.
(Protection circuit)

Further, a protection circuit for the secondary battery 39 is mounted on the pack substrate 74. The protection circuit is connected to each battery lead plate 80 via the signal lead wire 84, and detects the battery voltage of each secondary battery 39, for example. The protection circuit is also connected to temperature detecting means 54 for detecting the battery temperature via a signal lead wire 84 separately.
(Signal terminal 35)

In addition to the charge / discharge terminal 34, the pack substrate 74 also includes a signal terminal 35 that outputs the output of the protection circuit, battery information, and the like as the external connection terminal 33. These charge / discharge terminals 34 and signal terminals 35 are exposed from the surface of the casing 31 as shown in FIG. For this reason, a vertical groove 38 is formed in the upper casing 31A as shown in FIGS.
(Secondary battery 39)

The casing 31 is formed in a shape that can incorporate the secondary battery 39 therein. Here, a cylindrical secondary battery in which an outer can is formed in a cylindrical shape extended in the longitudinal direction is used as the secondary battery. As shown in FIGS. 3 to 8, the casing 31 has a plurality of secondary batteries 39 arranged in a substantially parallel posture in the casing 31 so as to be adjacent side by side on the same plane. The secondary battery 39 built in the battery pack 30 is a lithium ion battery. However, the secondary battery may be any other battery that can be charged, such as a nickel metal hydride battery, a nickel cadmium battery, or a polymer battery. A plurality of secondary batteries can be connected in series to increase the output voltage, and can be connected in parallel to increase the output current. In this example, the secondary battery 39 is a lithium ion battery, four are connected in series, and the output voltage is 14.4V. If five batteries are connected in series, the output voltage will be 18V. However, the battery pack does not specify the number of built-in secondary batteries or the connection state. In the battery pack, the number of secondary batteries incorporated and the output voltage can be designed in various ways according to the type and application of the electric equipment to be used.
(Battery storage space)

The battery storage space of the battery holder 70 is partitioned by a spacer wall 72 as shown in the perspective views of FIGS. 8 and 9, and stores adjacent secondary batteries 39 in an electrically isolated manner. A plurality of spacer walls 72 are provided so as to protrude downward, and the secondary battery 39 is accommodated between the spacer walls 72 from below. In the example of FIGS. 8 to 10, three spacer walls 72 are provided to house the four secondary batteries 39, and the secondary batteries are located at both ends as shown in FIGS. 6 to 9 and the like. Only the upper part of the side surface of 39 is covered with the holder side wall 73 and is exposed from the side surface of the secondary battery 39 to the lower side. In addition, as shown in FIGS. 8 and 9, the storage position of each secondary battery 39 is curved above the battery holder 70 so as to coincide with the side surface of the cylindrical secondary battery 39. As a result, the battery storage space is opened downward in an inverted U shape in cross section, and the secondary battery 39 is inserted from the battery storage space opened downward. The spacer wall 72 is formed so as to extend downward from between the adjacent secondary batteries 39, and is not protruded from the upper surface side of the battery holder 70. Furthermore, a substrate fixing portion 75 for fixing the pack substrate 74 is provided on the upper surface side of the battery holder 70.
(Spacer wall 72)

The spacer wall 72 is provided with a width substantially equal to or slightly smaller than the diameter of the secondary battery 39 so that the secondary battery 39 can be held in a state in which the secondary battery 39 is accommodated between the spacer walls 72. The battery holder 70 is formed of a resin such as plastic that is excellent in insulation and heat insulation and has flexibility, and the spacer wall 72 is provided integrally with the battery holder 70. Thus, the secondary battery 39 is elastically deformed in a state where the secondary battery 39 is inserted between the spacer walls 72 and the side surface of the secondary battery 39 is pressed and held so as not to come off. At the same time, the adjacent secondary batteries 39 can be insulated and insulated from each other by the spacer wall 72. For example, even when any of the secondary batteries reaches a high temperature, the situation where heat is propagated to the adjacent secondary batteries can be reduced.
(Expression 71)

Furthermore, the end surface of the battery holder 70 is provided with an exposed portion 71 that at least partially exposes the end surface of the secondary battery 39 stored in the battery storage space. The exposed portion 71 is formed smaller than the end surface so as to expose the end surface of the secondary battery 39 while preventing the secondary battery 39 from falling off. In the example of FIGS. 8 to 9 and the like, it is formed in a U shape partially covering the upper part and the side part of the end face of the secondary battery 39 and opening the lower part. The battery holder 70 connects the end surfaces exposed from the exposed portion 71 with the battery lead plate 80 in a state where the secondary battery 39 is stored in the battery storage space.
(Battery lead plate 80)

  As shown in the perspective views of FIGS. 8 and 11, the battery lead plate 80 is a flat metal plate having excellent conductivity, and is formed in a size that can be accommodated in the exposed portion 71. The battery lead plate 80 is formed with a welding slit for spot welding, and is fixed to the end surfaces of the adjacent secondary batteries 39 while being accommodated in the battery accommodating space.

Conventionally, in order to prevent a situation where the battery core is detached from the battery holder during the assembly operation, the secondary battery is bundled with the battery holder with a tape or the like. On the other hand, in the present embodiment, since the secondary battery is fixed by the battery lead plate 80, fastening using such a tape or the like can be made unnecessary, and work efficiency at the time of assembly can be improved. Conventionally, in order to avoid a situation where the battery cores come into contact with each other during an assembling operation and are short-circuited, an insulating plate is attached to the end face of the battery core. In contrast, in the present embodiment, by covering the battery core with the battery holder 70, an unintended short circuit between adjacent battery cores during assembly work can be avoided.
(Fixing structure of signal lead wire 84 and battery lead plate 80)

  Further, the battery lead plate 80 forms a lead fixing portion 81 for fixing the signal lead wire 84. In the example of FIGS. 11 and 12, the lead fixing portion 81 is a hole formed so as to protrude from substantially the center of the upper portion of the battery lead plate 80. The signal lead wire 84 is inserted into the hole and fixed by soldering, and the battery lead plate 80 is connected to the pack substrate 74 via the signal lead wire 84. Particularly in this example, the battery voltage of each secondary battery 39 is detected and sent to the pack substrate 74.

Since such a hole is generally small, the operation of passing the signal lead wire through the hole is not easy and takes time. Therefore, in the present embodiment, as shown in FIG. 12, when the cylindrical secondary batteries 39 are adjacent to each other, the lead fixing portion 81 is formed in a valley generated in a portion where the side surfaces of the secondary batteries 39 are in contact with each other. It arrange | positions so that a hole may be located. With this configuration, the signal lead wire 84 is advanced to the battery lead plate 80 side with the signal lead wire 84 placed in the valley between the secondary batteries, so that the tip of the signal lead wire 84 is inevitably guided to the valley between the secondary batteries. Thus, it can be inserted into the hole of the lead fixing part 81 as it is, and the hole passing work of the signal lead wire 84, which has been troublesome in the past, can be greatly saved, and the assembly work efficiency can be improved.
(Board fixing part 75)

A substrate fixing portion 75 for fixing the pack substrate 74 is provided on the upper surface of the battery holder 70. As shown in the exploded perspective view of FIG. 8 and the like, the substrate fixing portion 75 is formed at substantially the center where the secondary batteries 39 are arranged, and a screw hole for screwing the pack substrate 74 is formed. The pack substrate 74 has a screw hole penetrating the pack substrate 74 at the center, and is fixed to the upper surface of the battery holder 70 by screws.
(Guide boss 76, guide rib 77)

Further, as shown in FIG. 5 and the like, a guide boss 76 and a guide rib 77 are provided on the upper surface of the battery holder 70 as guide members for guiding the lead wires. In the conventional assembling method, in the case of using a lead wire, the lead wire is prepared longer than the length of the shortest distance originally required in consideration of the ease of soldering work. However, in this case, after fixing the lead wire by soldering or the like, the lead wire is not completely fixed because it is longer than the required length, and as a result, the lead wire is free in the casing after assembly. In a so-called violent state, there was a possibility of hitting another member or causing a disconnection or a short circuit due to contact or rubbing. In addition, in order to avoid such a problem, for example, a member and a structure for fixing the lead wire are separately prepared, such as fastening the lead wire with a binding band, but the labor and cost are extra. Take it. Therefore, in this embodiment, a guide boss 76 and a guide rib 77 are provided as guide members for guiding the lead wire. The guide boss 76 is provided at a plurality of locations in a cylindrical shape, and the lead wire is defined by bending, winding, or passing the lead wire with the guide boss 76. The guide rib 77 is provided with a parallel plate, and a lead plate is inserted between the parallel plates for guidance. In addition, a protrusion is provided between the parallel plates so that the opening portion is narrowed as necessary. The lead wire is pressed by the protrusion so that the lead wire does not fall out between the guide ribs 77. Hold on. These guide bosses 76 and guide ribs 77 can be formed on the upper surface of the battery holder 70 by integral molding. As described above, the lead wire can be held in a predetermined posture by using the plurality of guide bosses 76 and the guide ribs 77, and it is possible to reduce the trouble of bundling the lead wires as in the prior art, and lead with a simple structure. The wire can be stably held, and the reliability of the wire can be improved by reducing the risk of rubbing or disconnection due to movement.
(Temperature detection means 54)

Further, the battery holder 70 is fixed with temperature detecting means 54 for detecting the temperature of the secondary battery 39. As the temperature detection means 54, a temperature sensor such as a thermistor that can detect temperature information as an electrical signal can be used. As shown in FIG. 8 and the like, the temperature detecting means 54 is fixed between secondary batteries positioned in the middle among the plurality of secondary batteries 39. In general, the temperature detecting means is often fixed to the secondary battery at the corner. However, in a configuration in which a plurality of secondary batteries are stored side by side in the casing, the heat tends to be trapped in the interior. It is considered that the temperature becomes higher than the corner. Therefore, in order to effectively detect the temperature of the secondary battery with a small number of temperature detection means, in this example, by arranging the temperature detection means between the intermediate secondary batteries, the temperature of the highest secondary battery Can be detected, and the highest battery temperature information is sent to the pack substrate side, thereby improving safety.
(Temperature detection insertion hole 55)

In the example of FIG. 8, the temperature detection insertion hole 55 is opened on the upper surface of the battery holder 70, and in contact with both adjacent secondary batteries between the secondary batteries 39 on the back side of the temperature detection insertion hole 55. The temperature detection means 54 is arranged in this manner, and the signal lead wire 84B connected to the temperature detection means 54 is pulled out from the temperature detection insertion hole 55 and sent to the pack substrate 74. In this example, the pack substrate 74 is fixed at a position where the temperature detection insertion hole 55 is closed. As a result, the opening portion can be closed with the pack substrate 74, and there is an advantage that the possibility of foreign matter such as dust and water entering the battery holder 70 through the temperature detection insertion hole 55 can be reduced. Further, an effect that the electrical connection distance between the temperature detecting means 54 and the pack substrate 74 can be shortened is also obtained.
(Soldering structure between lead plates)

A substrate lead plate is also fixed on the pack substrate 74. In examples such as FIG. 6 and FIG. 7, the board lead plate is an external connection terminal 33 for connecting to a charging terminal of a charger that charges the battery pack 30. The external connection terminal 33 is connected to the battery core by the output lead wire 83 connected to the second output lead plate 82B and the output lead plate 82. That is, each battery lead plate 80 located on the end face of the battery core in which the four secondary batteries 39 are connected in series serves as a positive output and a negative output, respectively, and one of them is output via the second output lead plate 82B. The wire 83 and the other are connected to the output lead plate 82, respectively.
(Narrowing piece 86)

  As shown in FIG. 7, a terminal connection portion 33a is provided on the back surface of the external connection terminal 33, and the output lead wire 83 is inserted into a connection hole 33b opened in the terminal connection portion 33a and soldered. On the other hand, the output lead plate 82 is soldered to the external connection terminal 33. Specifically, as shown in FIG. 13, a U-shaped notch is formed on the side surface of the external connection terminal 33, and the holding piece 86 formed by the notching is bent outward and is inverted V-shaped. A gap is formed. As shown in FIG. 14, the upper end of the output lead plate 82 is inserted into this gap, and a part of the output lead plate 82 is sandwiched and temporarily fixed by the holding pieces 86. In this state, soldering with the solder 87 as shown in FIG. 3 makes it easy for the solder to flow into the gap, and the metal plates can be easily soldered together.

  As a result, it is possible to obtain an excellent advantage that it is possible to easily fix the lead plates by soldering, which was not easy in the past. In other words, conventional soldering between lead plates would result in contact between surfaces, so it would be necessary to temporarily fix the lead plates together in a predetermined posture. However, it is difficult to obtain sufficient strength due to poor solder familiarity and wetting due to the fact that the lead plate itself is not easily fixed and the heat conduction of the lead plate itself is good. On the other hand, according to the above configuration, the lead plates can be temporarily fixed with a very simple structure in which a lead plate is cut and another lead plate is sandwiched in the gap, and solder flows into the gap on the contact surface. This makes it possible to realize soldering between metal plates that is extremely simple and effective. In addition, a special member or structure for temporarily fixing the lead plates to each other can be eliminated, and the lead plates can be fixed to each other with a minimum space. In particular, since the amount of protrusion in the lateral direction from the lead plate can be minimized, it is possible to avoid an increase in the fixed portion. Furthermore, since one terminal component can be used for soldering lead plates and lead wires, it can also contribute to a reduction in the number of components.

In the above example, the sandwiching piece 86 is formed in the external connection terminal 33 and the output lead plate 82 is sandwiched in the gap formed here. However, the present invention is not limited to this configuration. Needless to say, it is possible to form a sandwiching piece and sandwich the external connection terminal in the gap. In the above example, the external connection terminal is connected to the battery core by a combination of the output lead wire and the output lead plate, so that the secondary battery can be efficiently wired in the limited space available in the casing. However, depending on, for example, the available space and the state of intersection with the signal lead wire, both are connected with the second output lead plate and the output lead wire, or both are connected to the output lead without using the lead wire. It is also possible to connect only with a plate.
(Sheet member 56)

The battery holder 70 described above is accommodated in the casing 31 as shown in the exploded perspective view of FIG. A sheet member 56 is preferably interposed between the battery holder 70 and the lower casing 31B. The sheet member 56 is formed of a material (for example, silicone) having excellent insulating properties and heat insulating properties. Further, by providing the seat member 56 with cushioning properties, an effect of absorbing and mitigating an external impact can be obtained. It can also contribute to the reduction of the clearance between the battery holder and the bottom of the casing.
(Concavity and convexity 78)

Furthermore, a plurality of ridges 78 are provided on the contact surface between the outer surface of the battery holder 70 and the inner surface of the casing 31. As shown in the perspective views of FIGS. 6 and 7, the uneven stripe 78 has a slit shape extending in the vertical direction in a region other than the exposed portion 71 where the battery lead plate 80 is exposed at the end face of the battery holder 70. Is formed. As shown in the horizontal cross-sectional view of FIG. 10, the surface of the battery holder 70 comes into contact with the inner surface of the casing 31 in an uneven shape, and an air layer is formed in the recess. As a result, the contact area between the battery holder 70 and the casing 31 is reduced, and the heat conduction from the battery holder 70 to the casing 31 is suppressed by the heat insulating effect of the air layer, and the situation where the casing 31 gets hot can be reduced. In particular, as shown in FIG. 10, by making the ridges 78 into a slit shape extending in the vertical direction, the effect of the natural convection of the air inside the casing 31 by heat is obtained, and the heat stays in one place by the movement of air. As a result, not only a heat insulation effect but also a heat conduction effect inside the casing 31 can be obtained.
(Lead air layer)

  In addition, the battery lead plate 80 is disposed in the exposed portion 71, and a gap is provided between the battery lead plate 80 disposed in the exposed portion 71 and the inner surface of the casing 31 to form a lead air layer. Here, the thickness of the battery lead plate 80 is made thinner than the thickness of the side surface of the battery holder 70 constituting the exposed portion 71. Thereby, even if the battery lead plate 80 generates heat due to the discharge of the secondary battery 39, the lead air layer is not directly brought into contact, and the heat insulation effect is enhanced so that the outside of the casing 31 is heated by the heat of the battery lead plate 80. The situation where it is heated can be reduced.

  In this way, it is possible to avoid a situation in which the casing is heated more than necessary due to heat generated when the battery pack is discharged or charged, and the user can easily touch the battery pack with a hand or the like. Furthermore, the contact area between the battery holder fixed inside the casing and the casing is reduced by the ridges and the exposed parts, so that the battery holder is held in a floating state, so that it is held at multiple points rather than the surface. For example, even when an impact is applied from the outside, direct stress is transmitted to the battery holder to reduce the impact and pressure on the secondary battery, and a protective effect can be obtained.

In the above example, the concave and convex stripes are formed in a slit shape. However, the present invention is not limited to this example, and a shape capable of forming a space between the outer surface of the battery holder and the inner surface of the casing can be used as appropriate. For example, the projections and depressions may be formed in a dot shape such as a circle or a polygon.
(Holding convex part 37)

  The holding projection 37 is movably accommodated in the casing 31 so as to be partially exposed from the casing 31 as shown in FIGS. Holding convex part 37 has an operation part on the upper surface, and has an inclined surface inclined to face the traveling direction when battery pack 30 is mounted on the lower surface, and a vertical surface formed continuously from the inclined surface. A locking hook 37b is provided. The locking hook 37b is integrally formed with the operation unit. The mounting portion 2 is formed with a holding recess 17 at a position corresponding to the locking hook 37b. The holding recess 17 also has a recess inclined surface that matches the inclined surface and a recess vertical surface that matches the water surface.

A state in which the battery pack 30 is attached to a dedicated charger is shown in FIGS. 15 is a perspective view showing a state in which the battery pack 30 is mounted on the battery pack charger 100, and FIG. 16 is a perspective view showing a state in which the battery pack 30 is removed from the battery pack charger 100 in FIG. 17 is a longitudinal sectional view taken along line XVII-XVII of the battery pack charger 100 of FIG. 15, and FIG. 18 is a longitudinal sectional view showing a state in which the battery pack 30 is removed from the battery pack charger 100 of FIG. FIG. 19 is a cross-sectional view taken along line XIX-XIX in FIG. As shown in these drawings, the locking hook 37b is biased so as to protrude downward by an elastic member 57 such as a coil spring. When the battery pack 30 is attached to the attachment portion 2, the inclined portion is pressed and contracted along the advancing direction in which the battery pack 30 is slid to allow the battery pack 30 to advance. When the battery pack 30 is advanced to a predetermined position, the locking hook 37b is accommodated in the holding recess 17 formed corresponding to this position, and the locking hook 37b is pressed by the elastic member 57, so that the vertical surface is It comes into contact with the vertical surface of the recess and is locked. In this state, even if a force is applied in the direction of pulling out the battery pack 30 from the mounting portion 2, the locked state is maintained by the vertical surface coming into contact with the concave vertical surface, and the battery pack 30 is prevented from sliding. When the user removes the battery pack 30 from the battery pack charger 100, the locking hook 37b and the holding recess 17 are locked by operating the operation portion of the holding projection 37 by hand. Is released, the battery pack 30 is allowed to slide, and becomes removable. In the battery pack 30, the mounting guide 50 is inserted and slid into the pack guide 60 provided on the side surface and is pushed all the way into the mounting portion 2, and the external connection terminal 33 of the battery pack 30 is connected to the battery pack charger 100. The battery terminal is brought into contact with the connection terminal 3, and the holding convex part 37 is further engaged with the holding concave part 17 and is attached to the battery pack charger 100.
(Installation guide 50)

  In order to slide the battery pack 30 in a correct posture along the bottom surface 2A of the mounting portion 2, a guide convex portion protruding from the inner surface is projected as a mounting guide 50 on the opposite side wall 6 of the case 1. Further, on both side surfaces of the casing 31 of the battery pack 30, guide grooves for guiding the guide convex portions are provided as pack guides 60. As shown in the cross-sectional view of FIG. 19, the guide groove is formed in a concave shape into which the guide convex portion can be inserted. When the battery pack 30 is mounted on the mounting portion 2, the guide convex portion can guide the battery pack 30 to the mounting portion 2 in a correct posture by guiding it to guide grooves provided on both side surfaces of the battery pack 30. The guide protrusion can be provided integrally with the side wall 6 by being positioned on the side where the battery pack 30 is inserted. The guide convex portion is provided so as to extend in the mounting direction of the battery pack 30, and the battery pack 30 to be mounted on the mounting portion 2 is slid along the guide convex portion to connect the external connection terminal 33 of the battery pack 30 to the mounting portion. 2 can be contacted in the correct posture.

In the above-described example, the guide convex portion is provided on the mounting portion 2 side and the guide groove is provided on the battery pack 30 side. However, the present invention is not limited to this configuration. For example, the guide convex portion is provided on the battery pack side. A guide groove may be provided on the mounting portion side.
(External connection terminal 33)

  As described above, the battery pack 30 includes a plurality of external connection terminals 33 for connection to electrical devices and chargers. For example, when the battery pack 30 is attached to the battery pack charger 100, the plurality of connection terminals 3 arranged on the attachment portion 2 of the battery pack charger 100 and the external connection terminal 33 are connected to each other. The plurality of external connection terminals 33 are arranged on the set surface 32 that is the bottom surface facing the bottom surface 2 </ b> A of the mounting portion 2 in a state where the battery pack 30 is mounted on the mounting portion 2 of the battery pack charger 100. In the illustrated battery pack 30, a step recess 36 is provided on the bottom surface of the casing 31, and the fixed protrusion 9 protruding from the mounting portion 2 of the battery pack charger 100 is guided to the step recess 36 and the mounting portion 2. It is set to a fixed position.

Further, the battery pack 30 of FIGS. 1 to 3 is provided with a plurality of rows of vertical grooves 38 on the set surface 32 in parallel, and an external connection terminal 33 that is an elastic contact is provided inside the vertical groove 38. The external connection terminal 33 which is an elastic contact is sandwiched and electrically connected to the plate-like connection terminal 3 inserted into the longitudinal groove 38 while being elastically pressed from both sides. The external connection terminal 33 in the figure includes a charge / discharge terminal 34 disposed on both sides and a signal terminal 35 disposed between the charge / discharge terminals 34. The charging / discharging terminals 34 on both sides are connected to the charging terminal 4 of the battery pack charger 100, and the intermediate signal terminal 35 is connected to the non-charging terminal 5 that is a signal terminal of the battery pack charger 100. The plurality of signal terminals 35 are terminals for transmitting information of the plurality of secondary batteries 39 built in the battery pack 30 to the outside. The signal terminal 35 can be an identification signal terminal that outputs an abnormality signal, a temperature signal, an identification signal, or the like of the secondary battery 39 built in the battery pack 30, for example. In this example, the charge / discharge terminal 34 and the signal terminal 35 are shared, and the manufacture of the four external connection terminals 33 is simplified.
(Charging circuit 20)

  The battery pack charger 100 has a built-in charging circuit 20 for charging the battery pack 30 attached to the attachment portion 2. The positive and negative charging terminals 4 arranged on both sides of the battery pack charger 100 are connected to the positive and negative charging / discharging terminals 34 of the battery pack 30 set in the mounting portion 2 to supply charging power to the battery pack 30. . As shown in the circuit diagram of FIG. 20, the charging terminal 4 on the positive electrode side is connected to the charging circuit 20 and supplies power to the battery pack 30 to charge the built-in secondary battery 39. The battery pack charger 100 shown in the figure converts AC power supplied from a commercial power supply (not shown) into DC by the rectifier circuit 22 and converts the DC voltage into charging voltage by the charging circuit 20. Output from the charging terminal 4. For example, the charging circuit 20 changes the duty for controlling ON / OFF of a switching element (not shown) connected between the output side of the rectifier circuit 22 and the charging terminal 4 on the positive electrode side, thereby changing the battery The charging voltage and charging current are optimally adjusted for charging the pack 30.

  The non-charging terminal 5 disposed between the pair of charging terminals 4 is a signal terminal. The connection terminal 3 shown in the figure has two signal terminals. These signal terminals are an abnormality signal terminal to which an abnormality signal of the secondary battery 39 built in the battery pack 30 is inputted, and a temperature signal terminal to which a temperature signal of the secondary battery 39 built in the battery pack 30 is inputted. And an identification signal terminal to which an identification signal of the secondary battery 39 incorporated in the battery pack 30 is input. However, the signal terminal can also be a signal terminal that transmits signals other than these, for example, the state of charge of the battery and various information of the battery.

  When an abnormal signal is input to the abnormal signal terminal, the control circuit 21 determines that the battery pack 30 is abnormal, and switches the charging circuit 20 off to stop charging. Further, the control circuit 21 detects the temperature of the secondary battery 39 built in the battery pack 30 from the temperature signal input to the temperature signal terminal. When the battery temperature becomes higher than the maximum temperature, the control circuit 21 interrupts charging by interrupting the charging current, or reduces the charging current to reduce the battery temperature. When the battery temperature becomes lower than the set temperature, the battery is charged with a normal charging current.

  Further, the control circuit 21 determines the optimum voltage and current value for charging the battery pack 30 from the battery identification signal input from the identification signal terminal, and changes the charging voltage and charging current output from the charging terminal 4. In the battery pack charger 100, when the battery pack 30 is mounted, the control circuit 21 receives the battery identification signal output from the control unit 40 of the battery pack 30, and the control circuit 21 receives the input battery. The type of the battery pack 30 is discriminated from the identification signal, and the charging circuit 20 is controlled so as to obtain the optimum voltage and current value for charging the battery pack 30. The battery pack charger 100 determines the charging voltage and charging current for charging the battery pack 30 from the battery identification signal input from the battery pack 30 and switches to the optimum voltage for charging. Multiple types of battery packs with different output voltages can be charged with the pack charger. However, the battery pack charger does not necessarily need to switch the output voltage, and can charge the battery pack with a constant output voltage.

  The battery pack according to the present invention can be suitably used as a battery pack for electric tools, and a battery pack for portable devices such as assist bicycles, electric bikes, and mobile phones.

DESCRIPTION OF SYMBOLS 1 ... Case 2 ... Mounting part; 2A ... Bottom surface 3 ... Connection terminal 4 ... Charging terminal 5 ... Non-charging terminal 6 ... Side wall 9 ... Fixed convex part 17 ... Holding recessed part 20 ... Charging circuit 21 ... Control circuit 22 ... Rectification circuit 30 ... Battery pack 31 ... casing; 31A ... upper casing; 31B ... lower casing 32 ... set surface 33 ... external connection terminal; 33a ... terminal connection portion; 33b ... connection hole 34 ... charge / discharge terminal 35 ... signal terminal 36 ... step recess 37 ... Holding convex part; 37b ... Locking hook 38 ... Vertical groove 39 ... Secondary battery 40 ... Control part 41 ... Charge / discharge switch 42 ... Temperature sensor 43 ... Current detection resistor 50 ... Mounting guide 54 ... Temperature detection means 55 ... Temperature detection insertion Hole 56 ... Sheet member 57 ... Elastic member 60 ... Pack guide 70 ... Battery holder 71 ... Exposed portion 72 ... Spacer wall 73 ... Holder side wall 74 ... Pack substrate 75 ... Substrate fixing portion 76 ... Guide boss 7 ... Guide rib 78 ... Concavity and convexity 80 ... Battery lead plate 81 ... Lead fixing portion 82 ... Output lead plate; 82B ... Second output lead plate 83 ... Output lead wires 84, 84B ... Signal lead wire 86 ... Nipping piece 87 ... Solder 100 ... Battery pack charger

Claims (9)

A battery pack comprising a rechargeable secondary battery (39),
A battery holder (70) for holding a plurality of rechargeable secondary batteries (39);
A battery lead plate (80) for connecting the secondary batteries (39) to each other at their end faces;
A pack substrate (74) on which a protection circuit for the secondary battery (39) is mounted;
A casing for housing the battery holder (70) and the pack substrate (74);
With
On the end face of the battery holder (70), the battery lead plate (80) is held in a posture and is exposed,
A battery pack comprising a plurality of ridges (78) provided on a contact surface between the battery holder (70) and the casing. The battery pack according to claim 1,
The battery holder (70) forms an exposed portion (71) for exposing the battery lead plate (80) at its end face,
The battery lead plate (80) is disposed in the exposed portion (71), and between the battery lead plate (80) disposed in the exposed portion (71) and the inner surface of the casing. A battery pack comprising a gap in the battery pack. The battery pack according to claim 1 or 2, further comprising:
The battery lead plate (80) and the pack substrate (74) includes a lead wire for wiring,
A battery pack, wherein a guide boss (76) for guiding the lead wire is provided on an upper surface of the battery holder (70). The battery pack according to any one of claims 1 to 3, further comprising:
An output lead plate (82) for wiring the secondary battery (39) and the pack substrate (74);
A substrate lead plate connected to the pack substrate (74);
With
Either one of the board lead plate or the output lead plate (82) is partially cut, and is bent at the cut portion to form a V-shaped gap. A battery pack characterized in that the other lead plate is sandwiched and the sandwiched portion is soldered. The battery pack according to claim 4,
The battery pack, wherein the board lead plate also serves as an external connection terminal (33) for connecting to a charging terminal of a charger for charging the battery pack. The battery pack according to claim 5,
The battery pack, wherein the external connection terminal (33) is connected to the secondary battery (39) by the output lead plate (82) and the output lead wire (83). The battery pack according to any one of claims 1 to 6,
The secondary battery (39) is a cylindrical battery extended in the longitudinal direction,
Further, the plurality of cylindrical batteries are arranged adjacent to each other in parallel,
The battery lead plate (80) forms a lead fixing part (81) for fixing the lead wire,
The battery lead plate (80) is fixed to the end face of the secondary battery (39) in a state where the lead fixing part (81) is located in a valley portion between adjacent cylindrical secondary batteries (39). A battery pack characterized by being made. The battery pack according to any one of claims 1 to 7, further comprising:
Temperature detecting means (54) for detecting the temperature of the secondary battery (39),
The temperature detection means (54) is arranged between the secondary batteries (39) positioned in the middle of the plurality of secondary batteries (39) arranged side by side in the casing. Battery pack. The battery pack according to claim 8, wherein
The temperature detection means (54) is connected to the pack substrate (74) via a signal lead wire (84),
The battery holder (70) has a temperature detection insertion hole (55) through which the signal lead wire (84) is passed,
The battery pack, wherein the pack substrate (74) is fixed on the upper surface of the battery holder (70) at a position where the temperature detection insertion hole (55) is opened.

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