JP7110798B2 - charging device - Google Patents

Description

The present invention relates to a charging device having a plurality of battery pack connections.

A charging device that charges a battery pack while cooling it with a cooling fan is widely known. Patent Literature 1 listed below discloses a charging device provided with a plurality of battery pack connecting portions to which a plurality of battery packs can be connected at the same time. This charging device has a duct that guides cooling air generated by one cooling fan to a plurality of battery pack connections. Patent Document 2 below discloses a configuration in which cooling air generated by a single cooling fan is separated by a duct into a first cooling air passage for cooling a charging circuit section and a second cooling air passage for cooling a battery pack. A charging device is disclosed.

JP 2016-92910 A JP 2015-19535 A

While the capacity of battery packs is increasing, there is a demand for shorter charging times, and charging currents are increasing. When the charging current is large, the heat generated in the charging circuit also increases. In the configuration of Patent Document 1, a plurality of battery packs can be cooled, but the charging circuit section cannot be cooled.

SUMMARY OF THE INVENTION An object of the present invention is to provide a charging device capable of cooling a plurality of connected battery packs while cooling a charging circuit unit.

One aspect of the present invention is a charging device. This charging device
a case forming an outer frame , having an upper surface portion, a lower surface portion facing the upper surface portion, and a plurality of side surface portions connecting the upper surface portion and the lower surface portion ;
a charging circuit unit accommodated in the case;
a fan housed in the case;
a plurality of battery pack connection portions provided on a first side portion of the plurality of side portions and a second side portion facing the first side portion ;
a plurality of first air duct end portions facing each of the plurality of battery pack connection portions; a second air duct end portion facing the fan; and a plurality of first air duct end portions and the second air duct end portions. and a guide portion that forms an air passage between the fan and the plurality of battery pack connections;
with
The connecting part is
the first air passage end portion facing the battery pack connection portion provided on the first side portion; the first air passage end portion facing the battery pack connection portion provided on the second side portion; a first connecting portion that connects the
a second connecting portion that connects the first connecting portion and the second air passage end portion;
has
A curvature of a connecting portion between the first connecting portion and the second connecting portion located away from the fan is different from that of the first connecting portion and the second connecting portion located closer to the fan. is smaller than the curvature of the connecting portion of the

The case may be provided with an air passage for cooling the plurality of battery packs connected to the plurality of battery pack connection portions and the charging circuit portion with cooling air generated by the fan.
Cooling air generated by the fan may be separated by the guide section into first cooling air flowing through the charging circuit section and second cooling air guided to the plurality of battery pack connecting sections.

The guide may consist of a single member.

The second connecting portion may be located off-center between the first and second side portions.

The fan may be arranged facing a third side portion connecting the first and second side portions.

The fan may be located off-center between the first and second side portions. Further, the fan may be located at a position avoiding between the battery pack connecting portions on the first and second side portions.

The guide portion located away from the fan may have a shape that allows cooling air to flow more easily than the guide portion located closer to the fan. Also, the fan may be a single fan.

A handle may be rotatably supported on the upper surface of the case.

A recess for accommodating the handle is provided on the upper surface of the case,
In the guide portion, lower surfaces of the first air passage end portion and the first connecting portion that are not adjacent to the recess are higher than lower surfaces of the first air passage end portion and the first connecting portion that are adjacent to the recess. may be in position.

Any combination of the above constituent elements, and conversion of expressions of the present invention between methods and systems are also effective as embodiments of the present invention.

According to the present invention, it is possible to provide a charging device capable of cooling a plurality of connected battery packs while cooling the charging circuit unit.

BRIEF DESCRIPTION OF THE DRAWINGS The perspective view of the charging device 1 which concerns on Embodiment 1 of this invention. 3 is a perspective view of a duct 20 of the charging device 1; FIG. 2 is a plan view of an upper case 4 of the charging device 1; FIG. 4 is a bottom view of the upper case 4; FIG. FIG. 2 is an explanatory diagram of the internal structure of the charging device 1; FIG. 6 is a sectional view taken along the line VI-VI of FIG. 5 and is a sectional view of the charging device 1 with a battery pack 70 attached to the battery pack connection portion 6d; VII-VII sectional view of FIG. 2 is a front view of charging device 1 with one battery pack 70 attached. FIG. FIG. 2 is a circuit block diagram of the charging device 1; 4 is a flowchart of charging mode determination in the charging device 1; 4 is a flowchart of lighting of a charging mode display LED 102 in the charging device 1; 4 is a graph showing an example of voltage values for switching between battery packs to be charged in the first mode of the charging device 1; 4 is a flow chart showing the flow of charging in the first mode of the charging device 1; 4A and 4B are explanatory diagrams of switching conditions of the battery pack to be charged in each of the first and second modes of the charging device 1; FIG. The bottom sectional view of charging device 1A concerning Embodiment 2 of the present invention. Planar sectional view of charging device 1A.

Preferred embodiments of the present invention will be described in detail below with reference to the drawings. The same or equivalent constituent elements, members, etc. shown in each drawing are denoted by the same reference numerals, and duplication of description will be omitted as appropriate. Moreover, the embodiments are illustrative rather than limiting the invention, and not all features and combinations thereof described in the embodiments are necessarily essential to the invention.

(Embodiment 1)
A charging device 1 according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 to 14. FIG. With reference to FIG. 1 , the front/rear, up/down, and left/right directions of the charging device 1 are defined. A case (housing) 3 forming a substantially rectangular parallelepiped outer frame of the charging device 1 is a combination of an upper case 4 and a lower case 5 . The upper case 4 and the lower case 5 are, for example, resin moldings.

The case 3 has an upper surface portion 3a, a lower surface portion 3b (FIGS. 6 and 7), and side surface portions 3c to 3f. The lower surface portion 3b faces the upper surface portion 3a. The side portions 3c to 3f connect the upper surface portion 3a and the lower surface portion 3b to each other. The side portion 3c is the front portion of the case 3 and corresponds to the first side portion. The side portion 3d is the back portion of the case 3 and corresponds to the second side portion. The side portion 3 e is the right side portion of the case 3 . The side portion 3f is the left side portion of the case 3 and corresponds to the third side portion. Side portions 3c and 3d face each other. The side portions 3e and 3f face each other. The lateral lengths of the side portions 3c and 3d are longer than the longitudinal lengths of the side portions 3e and 3f.

A handle 12 is rotatably supported on the upper surface portion 3 a of the case 3 . State display portions 14a to 14d are provided at four corners of the upper surface portion 3a of the case 3, respectively. The status display units 14a to 14d include light emitting elements such as LEDs (light emitting diodes). The status display units 14a to 14d notify the operator of the charging status of the battery packs connected to the battery pack connection units 6a to 6d by their own lighting states. A charging mode switching switch 13 is provided as a mode switching section at the center of the front portion of the upper surface portion 3a.

Battery pack connection portions 6 a and 6 b are provided on a side portion 3 c that is the front portion of the case 3 . As shown in FIG. 5 , battery pack connecting portions 6 c and 6 d are provided on a side portion 3 d that is the rear portion of the case 3 . Each of the battery pack connection portions 6a to 6d has a vent (intake port) 7 and a pair of rail portions 15. As shown in FIG. The intake port 7 communicates with the exhaust ports of the battery packs connected to the battery pack connecting portions 6a to 6d. The rail portion 15 extends vertically. The rail portion 15 serves as a guide when the battery pack is attached to the battery pack connection portions 6a to 6d. In the present embodiment, the vent holes 7 provided in the battery pack connection portions 6a to 6d are described as an intake port, and the vent holes of the battery pack are assumed to be an exhaust port. The mouth may be used as an intake port.

A vent (air inlet) 8 and a plug insertion port holder (outlet holder) 16 are provided on a side portion 3e, which is the right side portion of the case 3. As shown in FIG. A plurality of intake ports 8 are opened rearwardly and downwardly from the center of the side portion 3e. The plug socket holder 16 is provided with two plug sockets (outlets) 11 . AC 100 V is output to the plug insertion port 11 . By inserting a power cord of an external electrical device (not shown) into the plug insertion port 11, power can be supplied from the charging device 1 to the external electrical device. As shown in FIG. 5, a side surface portion 3f, which is the left side surface portion of the case 3, is provided with a ventilation port (exhaust port) 9. As shown in FIG. A plurality of exhaust ports 9 are opened rearwardly and downwardly from the center of the side portion 3f. In this embodiment, the vent 8 is described as an intake port, and the vent 9 is described as an exhaust port, but the vent 8 may be an exhaust port, and the vent 9 may be an intake port.

As shown in FIGS. 5 and 7, the case 3 accommodates a main board 50 and a fan 55 . The main board 50 is fixed to the lower surface of the lower case 5 by screws or the like. The main substrate 50 is mounted with each component that constitutes the charging circuit section. A fan 55 is held near the exhaust port 9 . The fan 55 is positioned rearward of the center of the case 3 in the front-rear direction, that is, the center between the side portions 3c and 3d. The fan 55 is an axial fan that sucks the air in the case 3 and exhausts it to the outside through the exhaust port 9 . The fan 55 is a single fan that generates cooling air for cooling the plurality of battery packs connected to the battery pack connectors 6 a to 6 d and the charging circuit section provided on the main board 50 .

A transformer 51, fins 52 to 54 for heat dissipation, a USB (Universal Serial Bus) board 56, a capacitor C, a plurality of FETs 58 as switching elements, and the like are provided on the main board 50. FIG. A USB connector 57 is provided on the USB board 56 . The USB connector 57 opens on the left side surface (side surface portion 3f) of the lower case 5. As shown in FIG. The power cord 17 is pulled out from the front portion of the right side surface (side surface portion 3e) of the case 3 and connected to an external AC power supply such as a commercial power supply. As shown in FIGS. 5 and 7, the air filter 59 is provided inside the case 3 and covers the intake port 8 . The air filter 59 prevents dust and the like from entering the interior of the case 3 from the exterior of the case 3 .

The wirings 61-64 electrically connect the battery pack connection portions 6a-6d and the main board 50 to each other. The wiring 65 electrically connects the switch board 31 fixed to the upper case 4 by screws or the like and the main board 50 to each other. The wirings 66 to 69 electrically connect the status display portions 14a to 14d and the main board 50 to each other. The switch board 31 is mounted with the mode changeover switch 13 shown in FIG. 1 and the like.

The duct 20 is a guide portion that forms an air passage between the fan 55 and the air inlets 7 of the battery pack connection portions 6a to 6d. The duct 20 is, for example, a resin molded body and is made of a single member. As shown in FIG. 2, the duct 20 includes first air passage ends 21a to 21d, a second air passage end 22, first connecting portions 23a to 23d, and a second connecting portion . The first air passage ends 21a to 21d respectively face (approach) the air inlets 7 of the battery pack connection portions 6a to 6d. The second air passage end 22 faces (approaches) the fan 55 .

The first connecting portions 23a and 23d extend substantially parallel to the front-rear direction and connect the first air passage ends 21a and 21d. The first connecting portions 23b and 23c extend substantially parallel to the front-rear direction and connect the first air passage ends 21b and 21c. The second connecting portion 24 extends substantially parallel to the left-right direction and connects the confluence of the first connecting portions 23 b and 23 c , the confluence of the first connecting portions 23 a and 23 d , and the second air passage end portion 22 . The second connecting portion 24 is positioned rearward of the center between the side portions 3c and 3d. The first connecting portion 23a is longer than the first connecting portion 23d. The first connecting portion 23b is longer than the first connecting portion 23c.

The first connecting portions 23a and 23d are positioned closer to the fan 55 than the first connecting portions 23b and 23c, that is, to the left. A connecting portion 25a between the first connecting portion 23a and the second connecting portion 24 and a connecting portion 25d between the first connecting portion 23d and the second connecting portion 24 have relatively large curvatures. A connecting portion 25b between the first connecting portion 23b and the second connecting portion 24, and a connecting portion 25c between the first connecting portion 23c and the second connecting portion 24 have a relatively smaller curvature than the connecting portions 25a and 25d. small curvature). As a result, the portion of the duct 20 located away from the fan 55 has a lower flow resistance than the portion located closer to the fan 55, and the cooling air generated by the fan 55 flows. The shape is easy to handle, and the amount of cooling air passing through the air inlets 7 of the battery pack connection portions 6a to 6d becomes nearly uniform.

As shown in FIG. 7, the lower end of the second air passage end 22 is located within the range of existence of the fan 55 and slightly above the center of the fan 55 in the vertical direction. The duct 20 separates the cooling air generated by the fan 55 into a first cooling air CA1 that flows through the charging circuit portion and a second cooling air CA2 that flows through the battery pack connection portions 6a to 6d.

The lower surface of the duct 20 is provided with a predetermined number of through holes 27 for screwing. As shown in FIG. 4 , a predetermined number of bosses 37 for screwing are provided on the lower surface of the upper case 4 at positions corresponding to the through holes 27 of the duct 20 . The duct 20 is fixed to the upper case 4 by screwing or the like. Ribs 30 , 34 , 35 are provided on the lower surface of the upper case 4 . The rib 30 is an air passage forming rib that is connected to the side surface of the duct 20 to form a part of the air passage. Ribs 34 are provided to hold the fan 55 in place. The rib 35 is provided above the second air passage end 22 of the duct 20 . The rib 35 guides the second cooling air CA2 so that it is efficiently sucked into the fan 55 .

As shown in FIG. 6, the upper surface portion 3a of the case 3 is provided with a recess 38 for accommodating the handle 12 therein. The concave portion 38 is present from near the center of the case 3 in the front-rear direction to the rear. The first connecting portion 23a of the duct 20 has a portion forward of the recess 38 (not close to the recess 38) and the lower surface of the first air duct end 21a is directly below the recess 38 (close to the recess 38). It is positioned higher than the lower surface of the portion, the lower surface of the first connecting portion 23d and the lower surface of the first air passage end portion 21d. Similarly, the first connecting portion 23b is such that the portion forward of the recess 38 and the lower surface of the first air passage end 21b overlap the lower surface of the portion directly below the recess 38, the first connecting portion 23c and the first air passage. It is positioned higher than the lower surface of the end portion 21c. This is to suppress the difference in ease of flow of the cooling air due to the existence of the concave portion 38 .

As shown in FIG. 6 , the battery pack 70 includes a battery case 71 and secondary battery cells 72 . A plurality of secondary battery cells 72 are accommodated and held within the battery case 71 . The battery case 71 is provided with an intake port (vent) 73 and an exhaust port (vent) 74 . The exhaust port 74 communicates with the intake port 7 of the charging device 1 . By attaching the battery pack 70 to one of the battery pack connection portions 6a to 6d, the battery pack 70 is fixed to the charging device 1 and an electrical connection (contact between terminals) with the charging device 1 is established, thereby charging. It becomes a state in which it can be charged by the device 1 . Since the intake port (vent port) 73 faces downward, it is possible to prevent dust and the like from entering the battery case 71 .

The flow of cooling air generated when the fan 55 is driven will be described. As shown in FIG. 7, the first cooling air CA1 is taken into the case 3 through the air inlet 8 of the case 3 and the air filter 59, cools each component on the main substrate 50, and is sucked into the fan 55. , is exhausted to the outside of the case 3 through the exhaust port 9 . As shown in FIG. 6, the second cooling air CA2 is taken into the battery pack 70 from the air inlet 73 of each battery pack 70 connected to the battery pack connection portions 6a to 6d, and blows each component in the battery pack 70. After being cooled, the air is taken into the case 3 from each air intake port 7 of the case 3, guided by the duct 20, sucked by the fan 55, and exhausted from the air outlet 9 to the outside of the case 3, as shown in FIG.

FIG. 9 is a circuit block diagram of the charging device 1. As shown in FIG. In the charging device 1 , the rectifier circuit 80 is, for example, a diode bridge, and rectifies the supply current from the AC power supply 79 . A transformer 81 and a switching element 82 such as an FET are provided between output terminals of the rectifier circuit 80 . On/off of the switching element 82 is controlled by a switching control circuit 83 . A rectifying/smoothing circuit 84 rectifies and smoothes the output current on the secondary side of the transformer 81 . The transformer 81, switching element 82, and rectifying/smoothing circuit 84 constitute a charging circuit. The 12V power supply 85 converts the output voltage of the rectifying/smoothing circuit 84 into an operating voltage (for example, DC 12V) of the fan 55 . A fan control circuit 86 controls driving of the fan 55 .

A voltage feedback circuit 87 detects the output voltage of the rectifying/smoothing circuit 84 and feeds it back to the switching control circuit 83 . A shunt resistor 88 is provided on the path of the output current (charging current) from the rectifying/smoothing circuit 84 to the battery pack connecting portions 6a to 6d. A current feedback circuit 89 detects the charging current from the voltage across the shunt resistor 88 and feeds it back to the switching control circuit 83 . A current detection circuit 91 detects the charging current from the voltage across the shunt resistor 88 and feeds it back to the microcomputer 90 . The overcharge detection circuit 92 detects whether the battery pack to be charged is overcharged. The charging mode display LED 102 displays the current charging mode of the charging device 1 under the control of the microcomputer 90 .

A microcomputer (microcontroller) 90 functions as a control unit. The microcomputer 90 controls the switching control circuit 83 so that the output voltage and the output current of the rectifying/smoothing circuit 84 correspond to the battery packs to be charged (among the battery packs connected to the battery pack connections 6a to 6d, to which charging current is currently supplied). (Battery packs that are in the state of being charged) are controlled so that they are at appropriate values according to the state and type. The microcomputer 90 also controls the fan control circuit 86 to control the driving of the fan 55 .

A transformer 98 and a switching control circuit 99 are provided between output terminals of the rectifier circuit 80 . Power sources 100 and 101 are provided on the secondary side of transformer 98 . A power supply 100 supplies an operating voltage for the switching control circuit 83 . A power supply 101 supplies an operating voltage (for example, DC 5V) for the microcomputer 90 . The voltage feedback circuit 87, the current feedback circuit 89, the microcomputer 90, the power supply 94, and the switching control circuit 83 are connected by using a photocoupler or the like to connect the primary side and the secondary side of the transformers 81 and 93. insulation can be ensured.

A C+ terminal and a C- terminal provided on each of the battery pack connection portions 6a to 6d are terminals for supplying charging current. The LS terminal is a terminal for receiving a temperature detection signal indicating the temperature of the battery pack from the battery pack. The T terminal is a terminal for receiving an identification signal indicating the type (rated voltage, etc.) of the battery pack from the battery pack. The battery pack connection portion 6a corresponds to port 1, the battery pack connection portion 6b to port 2, the battery pack connection portion 6c to port 3, and the battery pack connection portion 6d to port 4.

Diodes D1-D4 are provided in current paths from rectifying/smoothing circuit 84 to battery pack connecting portions 6a-6d, respectively, to prevent reverse current flow. Relays 93a to 93d as selection means are provided on current paths from rectifying/smoothing circuit 84 to battery pack connecting portions 6a to 6d, respectively. The relays 93a to 93d are selectively turned on under the control of the microcomputer 90 depending on which of the battery pack connectors 6a to 6d is connected to the battery pack to be charged. The voltage detection circuits 94a to 94d detect the voltage of each battery pack connected to the battery pack connections 6a to 6d and feed it back to the microcomputer 90. FIG. The overvoltage detection circuits 95a to 95d detect whether the battery packs connected to the battery pack connectors 6a to 6d are overvoltage or not, and feed back to the microcomputer 90. FIG. Temperature detection circuits 96 a - 96 d detect the temperature of each battery pack connected to battery pack connection portions 6 a - 6 d and feed it back to microcomputer 90 . The battery pack identification circuits 97a-97d detect the types of the battery packs connected to the battery pack connectors 6a-6d and feed them back to the microcomputer 90. FIG. The microcomputer 90 detects the type (rated voltage, etc.) and state (voltage and temperature) of the battery pack to be charged each time the battery pack to be charged is switched.

FIG. 10 is a flow chart of charging mode determination in the charging device 1 . The microcomputer 90 displays a charging standby display on the status display units 14a to 14d (S1). When the battery pack is connected to at least one of the battery pack connectors 6a to 6d (YES in S2), the microcomputer 90 checks the temperature of the connected battery pack, (NO in S3), the type or state of the battery pack is discriminated (S4). This step S4 is performed each time charging of the battery pack is started regardless of the charging mode described later. That is, it is performed each time the battery pack to be charged is switched. Thereby, the microcomputer 90 can accurately grasp the type or state of the battery pack before charging, and can perform accurate charging according to the type or state of the battery pack. When the normal mode as the second mode is selected as the charging mode of the battery pack (“Normal” in S5), the microcomputer 90 determines that charging is to be performed in order of port number (S6), and starts charging. (S8). When the simultaneous charging mode as the first mode is selected as the charging mode of the battery pack ("Simultaneous charging" in S5), the microcomputer 90 determines that control is to be performed to sequentially charge the batteries in descending order of voltage (S7). Charging is started (S8). In step S3, if the temperature of the battery pack is equal to or higher than a predetermined temperature, for example, 50° C. (YES in S3), the microcomputer 90 displays the status corresponding to the one of the battery pack connectors 6a to 6d to which the battery pack is connected. A high temperature standby display is displayed on the units 14a to 14d (S9), and the fan 55 is driven (S10). When only one battery pack is connected, if the high temperature is determined in step S3, steps S9 and S10 are executed until the high temperature state is resolved. On the other hand, in a state in which a plurality of battery packs are connected, it is conceivable that one battery pack is hot and the other battery packs are not. In this case, charging cannot be started if there is even one high-temperature battery pack in step S3. Therefore, in step S3, the temperatures of all the connected battery packs are detected, and if there is a battery pack that is not at a high temperature, the process proceeds to step S4 so that only the battery packs that are not at a high temperature can be charged, and the high temperature state is resolved. After that, the battery may be charged in the selected charging mode.

FIG. 11 is a flowchart of lighting of the charging mode display LED 102 in the charging device 1. FIG. When the charging mode switching switch 13 is pressed (YES in S11), the microcomputer 90 switches the charging mode between the first mode (simultaneous charging mode) and the second mode (normal mode), and switches the mode after switching to the simultaneous charging mode. If the charging mode is not set (NO in S12), the charging mode display LED 102 is turned on (S13). If the mode after switching is the simultaneous charging mode (YES in S12), the microcomputer 90 turns off the charging mode display LED 102 (S14).

FIG. 12 is a graph showing an example of voltage values for switching battery packs to be charged in the first mode (simultaneous charging mode) of the charging device 1 . In the simultaneous charge mode, first, all battery packs are charged to 3.8 V per secondary battery cell while switching the battery packs to be charged. After that, all the battery packs are charged to 3.95 V per secondary battery cell while switching the battery packs to be charged. Similarly, all the battery packs are charged stepwise to 4.1 V and 4.17 V per secondary battery cell.

FIG. 13 is a flow chart showing the flow of charging in the first mode of the charging device 1. As shown in FIG. The microcomputer 90 selects the battery pack with the lowest voltage (the battery pack with the lowest remaining capacity rate (or remaining capacity)) as the battery pack to be charged, and determines (detects) the type or state of the battery pack. Then, the target voltage is set to 3.8 V per secondary battery cell, and charging of the battery pack is continued until the voltage of the battery pack to be charged reaches 3.8 V per secondary battery cell (NO in S21). (S22). When the voltage of the battery pack to be charged reaches 3.8 V per secondary battery cell (YES in S21), the microcomputer 90 switches the battery pack to be charged to the battery pack with the lowest voltage among the remaining battery packs ( S23). The microcomputer 90 determines the type or state of the battery pack before charging the battery pack each time the switching is performed. Accordingly, the type or state of the battery pack to be charged can be accurately grasped, and accurate charging can be performed according to the type or state of the battery pack. The microcomputer 90 switches the battery pack to be charged each time the voltage of the battery pack to be charged reaches 3.8 V per secondary battery cell, and when the voltage of all battery packs reaches 3.8 V per secondary battery cell ( YES in S24), the target voltage is switched to 3.95 V per secondary battery cell (S25). The microcomputer 90 performs charging while switching the battery packs to be charged, and when the voltages of all the battery packs reach 3.95 V per secondary battery cell (YES in S26), the target voltage is changed to 4.1 V per secondary battery cell. (S27). The microcomputer 90 performs charging while switching the battery packs to be charged, and when the voltages of all the battery packs reach 4.1 V per secondary battery cell (YES in S29), the target voltage is set to 4.17 V per secondary battery cell. (S30). The microcomputer 90 performs charging while switching the battery packs to be charged, and when the voltage of all the battery packs reaches 4.17 V per secondary battery cell (YES in S31), the status display units 14a to 14d indicate completion of charging. (S32). Note that the microcomputer 90 detects the temperature of the battery pack to be charged (or all connected), and when the temperature of the switched battery pack is high (for example, 50° C. or higher), the temperature of this battery pack is Then switch to a battery pack with a lower voltage. After the voltage of the battery pack reaches the target voltage, the battery pack skipped due to the high temperature may be charged. However, if the high temperature condition continues, another battery pack may be charged, and charging of the battery pack may be started after the high temperature condition is resolved. Moreover, although FIGS. 12 and 13 show the voltage of each secondary battery cell 72 as the target voltage, charging may be performed stepwise based on the voltage of the battery pack (overall voltage). For example, in the case of a battery pack with a rated voltage of 18V, five secondary battery cells are connected in series. Therefore, the voltage of the battery pack is first charged to 19V (3.8V×5 cells), and then charged stepwise to 19.75V, 20.5V, and 20.85V. By determining the type or state of the battery pack each time the charging target is switched, it is possible to determine whether or not the same battery pack is connected. If the type of battery pack is determined only once until all connected battery packs are fully charged, and the battery pack is replaced with a different one midway through, the battery pack will be replaced by the previously connected battery. The information of the pack will be inherited, and there will be a problem that charging will end before it is fully charged. Therefore, in the present embodiment, charging can be reliably completed by always determining the type of the battery pack before charging is started (each time switching is obtained).

The microcomputer 90 can derive the remaining capacity rate of each battery pack from the relationship between the current output voltage of each battery pack and the output voltage when fully charged. By determining whether to switch the battery pack to be charged based on the remaining capacity ratio, it is possible to appropriately switch the battery pack to be charged even when a plurality of battery packs having different rated voltages are connected. In the first mode, the microcomputer 90 charges a plurality of battery packs having different remaining capacity ratios, and when the remaining capacity ratio of the battery pack to be charged is higher than the remaining capacity ratio of at least one other battery pack, the microcomputer 90 , the battery pack to be charged is switched without charging. When the microcomputer 90 detects an abnormality (high temperature abnormality, etc.) in the battery pack to be charged, the microcomputer 90 switches the battery pack to be charged without charging.

FIG. 14 is an explanatory diagram of switching conditions of the battery packs to be charged in each of the first and second modes of the charging device 1 . The second mode (normal mode) is a mode in which the battery packs are charged in order of port number, and after the battery pack to be charged is fully charged, the battery pack of the next port number is switched to. In the normal mode, if the battery pack to be charged is in the high-temperature standby state, the battery pack is skipped and the battery pack of the next port number is charged as the battery pack to be charged. When the high-temperature standby state is resolved, the battery pack being charged is charged as a battery pack to be charged after the charging of the battery pack is completed. Alternatively, after charging of all battery packs other than the battery pack is completed, the battery pack may be charged as the battery pack to be charged. If the battery pack being charged is removed, the battery pack with the next port number should be charged. Furthermore, when the battery pack is connected in the middle, charging may be performed in the order of the port numbers after the charging of the battery pack being charged is completed. For example, when the battery pack of port number 3 is being charged and the battery pack is connected to port number 2, the newly connected battery pack of port number 2 is charged after charging of the battery pack of port number 3 is completed. On the other hand, when battery packs are connected to port number 4, they can be charged in the order of their port numbers. In this second mode, the control from the start of charging of one battery pack to the completion of charging is a well-known technique that is generally performed. That is, when the battery pack is a lithium battery, charging is started by constant current charging, and when the voltage of the battery pack (or the voltage of the secondary battery cell) reaches a predetermined value, it is switched to constant voltage charging, and the charging current is a predetermined current. It is a control to stop charging as full charge when it drops to . In the first mode (simultaneous charging mode), the battery packs with the lowest voltage (remaining capacity ratio) are charged first, and the voltages (remaining capacity ratios) of the plurality of battery packs are increased step by step while the voltages (remaining capacity ratio) are uniform. When the battery pack to be charged is in the high-temperature standby state, battery packs other than the battery pack to be charged are charged sequentially in descending order of voltage. If some of the battery packs are removed in the middle, the remaining battery packs are charged in ascending order of voltage. When a battery pack is newly connected on the way, all battery packs including the new battery pack are charged in ascending order of voltage. In addition, in the first mode, even if the rated voltages of the connected battery packs are different, charging may be performed as shown in FIG. For example, if there is a battery pack with a small rated voltage, that battery pack will complete charging faster than the other battery packs. Since it is sufficient to continue charging the pack, there is no problem even if a plurality of battery packs with different rated voltages are connected. In addition, by detecting the battery pack type and state, it is possible to calculate the rated voltage and remaining capacity ratio of the battery pack (ratio of remaining capacity to the rated voltage). Even if the voltages are different, the charging can be completed almost at the same time.

According to this embodiment, the following effects can be obtained.

(1) The cooling air generated by the fan 55 is separated by the duct 20 into a first cooling air CA1 flowing through the charging circuit section and a second cooling air CA2 flowing through the battery pack connection sections 6a to 6d. Therefore, the fan 55 can cool the plurality of battery packs connected to the charging device 1 while cooling the charging circuit unit. Here, if the fan 55 is a single fan, the cost can be reduced and the wiring can be simplified as compared with the case where a plurality of fans are used for cooling. can be efficiently cooled.

(2) Since the duct 20 is a single member and can be screwed to the upper case 4, it separates the cooling air generated by the fan 55 into the first cooling air CA1 and the second cooling air CA2. It is possible to suppress an increase in the cost, the number of parts, and the manufacturing man-hours required for manufacturing. In addition, the duct 20 also has the function of guiding dust and water entering from the air inlet 7 toward the fan 55, and contributes to dust prevention and waterproofing inside the case 3 and outside the duct 20.

(3) An intake port 8 and a plug insertion port 11 for the first cooling air CA1 are provided on the side portion 3e of the case 3 where the battery pack connection portions 6a to 6d are not provided, and the battery pack connection portions 6a to 6d are provided. Since the exhaust port 9 and the USB connector 57 are provided on the side portion 3f that is not exposed to the air, the layout efficiency is good.

(4) Since the curvature of the connection portion 25b and the connection portion 25c located far from the fan 55 is made smaller than the curvature of the connection portion 25a and the connection portion 25d located close to the fan 55, both Compared to the case where the curvatures are equal, the amount of cooling air passing through the air inlets 7 of the battery pack connection portions 6a to 6d can be made nearly uniform. In addition, since the fan 55 is arranged at the end portion of the case 3 avoiding the center portion, the arrangement area for the main board 50 can be secured.

(5) In the first mode (simultaneous charging mode), the microcomputer 90 determines switching of the battery pack to be charged based on the remaining capacity of each of the plurality of battery packs, thereby allowing the plurality of battery packs with different rated voltages to be switched. is connected, the battery pack to be charged can be appropriately switched. Also, when a battery pack in a high temperature state is connected, the other battery packs are charged until the high temperature state is reached, so that a plurality of battery packs can be efficiently charged.

(6) In the first mode (simultaneous charging mode), the microcomputer 90 sequentially charges the battery packs with the lowest remaining capacities. Therefore, it is possible to charge the plurality of battery packs while quickly equalizing the remaining capacities of the battery packs. .

(Embodiment 2)
FIG. 15 is a bottom sectional view of charging device 1A according to Embodiment 2 of the present invention. FIG. 16 is a cross-sectional plan view of charging device 1A. The following description focuses on differences from the first embodiment. The charging device 1A has a fan 55A, an intake port (vent) 8A, an exhaust port (vent) 9A, and a main substrate 50A for the battery pack connectors 6a and 6d, and the battery pack connectors 6b and 6c. , it has a fan 55B, an intake port (vent) 8B, an exhaust port (vent) 9B, and a main substrate 50B.

The lower case 5 is provided with a rib 60 that divides the inside of the case 3 into two (substantially halves). The fan 55A, the air inlet 8A, the air outlet 9A, and the main board 50A are provided on the left side of the rib 60. As shown in FIG. A fan 55B, an air inlet 8B, an air outlet 9B, and a main substrate 50B are provided on the right side of the rib 60. As shown in FIG. The intake port 8</b>A opens on the lower surface of the right front portion of the left area of the rib 60 of the case 3 . The intake port 8</b>B opens in the left front lower surface of the right region of the rib 60 of the case 3 . The fan 55A is provided in the lower left rear part inside the case 3 . The fan 55B is provided at the bottom of the right rear portion inside the case 3 . The exhaust port 9</b>A is provided at the lower rear portion of the left side surface of the case 3 . The exhaust port 9</b>B is provided at the lower rear portion of the right side surface of the case 3 . The main board 50A is fixed to the lower surface of the left side area of the rib 60 of the case 3 by screwing or the like. The main substrate 50A carries a charging circuit section for charging the battery packs connected to the battery pack connection sections 6a and 6d. The main substrate 50B is fixed to the lower surface of the right side area of the rib 60 of the case 3 by screwing or the like. The main board 50B carries a charging circuit section for charging the battery packs connected to the battery pack connection sections 6b and 6c.

The ducts 20A and 20B as guide portions are fixed to the upper case 4 by screwing or the like. The duct 20A forms an air passage between the air intakes of the battery pack connecting portions 6a and 6d and the fan 55A. A duct 20B as a guide forms an air passage between the air intakes of the battery pack connecting portions 6b and 6c and the fan 55B. In the duct 20A, the first air passage end 21a facing the air inlet of the battery pack connection portion 6a is wider than the first air passage end 21d facing the battery pack connection portion 6d. Also, the curvature of the connecting portion 25a between the first connecting portion 23a and the second connecting portion 24A is smaller than the curvature of the connecting portion 25d between the first connecting portion 23d and the second connecting portion 24A. Considering that the first air passage end 21a is farther from the fan 55A than the first air passage end 21d, these configurations make the amount of cooling air passing through the air inlets of the battery pack connection portions 6a and 6d uniform. This is to bring it closer to The duct 20B is bilaterally symmetrical with the duct 20A.

Other points of this embodiment are the same as those of the first embodiment. According to the present embodiment, although two fans 55A and 55B are required, one battery pack and one charging circuit are cooled by one fan. Compared to cooling with one fan or cooling two battery packs with one fan, the cost can be reduced and the wiring can be simplified.

Although the present invention has been described above with reference to the embodiments, it will be understood by those skilled in the art that various modifications can be made to each component and each processing process of the embodiments within the scope of the claims. By the way. Modifications will be discussed below.

The number of battery packs that can be simultaneously connected to the charging device of the present invention is not limited to four, and can be any number.

1, 1A charging device (charger), 3 case (housing), 3a upper surface portion, 3b lower surface portion, 3c to 3f side surface portion, 4 upper case, 5 lower case, 6a to 6d battery pack connection portion, 7 intake port ( vent), 8, 8A, 8B intake port (vent), 9, 9A, 9B exhaust port (vent), 11 plug insertion port (outlet), 12 handle, 13 charge mode selector switch (mode selector) , 14a to 14d status display portion, 15 rail portion, 16 plug insertion holder (outlet holder), 17 power cord, 20 duct (guide portion), 21a to 21d first airway end, 22 second airway end part, 23a-23d first connection part, 24 second connection part, 25a-25d connection part, 27 through hole, 30 rib, 31 switch board, 34-35 rib, 37 boss, 50 main board, 51 transformer, 52- 54 fin, 55 fan, 56 USB board, 57 USB connector, 58 FET (switching element), 59 air filter, 60 rib, 61 to 69 wiring, 70 battery pack, 71 battery case, 72 secondary battery cell, 73 air intake (vent), 74 exhaust port (vent), 79 AC power supply, 80 rectifier circuit, 81 transformer, 82 switching element, 83 switching control circuit, 84 rectifying smoothing circuit, 85 12V power supply, 86 fan control circuit, 87 voltage feedback circuit, 88 shunt resistor, 89 current feedback circuit, 90 microcomputer (control unit), 91 current detection circuit, 92 overcharge detection circuit, 93a to 93d relays, 94a to 94d voltage detection circuit, 95a to 95d overvoltage detection circuit, 96a to 96d temperature detection circuit, 97a to 97d battery pack identification circuit, 98 transformer, 99 switching control circuit, 100 power supply, 101 power supply, 102 charging mode display LED, CA1 first cooling air, CA2 second cooling air

Claims (12)

a case forming an outer frame , having an upper surface portion, a lower surface portion facing the upper surface portion, and a plurality of side surface portions connecting the upper surface portion and the lower surface portion ;
a charging circuit unit accommodated in the case;
a fan housed in the case;
a plurality of battery pack connection portions provided on a first side portion of the plurality of side portions and a second side portion facing the first side portion ;
a plurality of first air duct end portions facing each of the plurality of battery pack connection portions; a second air duct end portion facing the fan; and a plurality of first air duct end portions and the second air duct end portions. and a guide portion that forms an air passage between the fan and the plurality of battery pack connections;
with
The connecting part is
the first air passage end portion facing the battery pack connection portion provided on the first side portion; the first air passage end portion facing the battery pack connection portion provided on the second side portion; a first connecting portion that connects the
a second connecting portion that connects the first connecting portion and the second air passage end portion;
has
A curvature of a connecting portion between the first connecting portion and the second connecting portion located away from the fan is different from that of the first connecting portion and the second connecting portion located closer to the fan. less than the curvature of the connecting part of the charging device. 2. The charging device according to claim 1, wherein the case is provided with an air passage for cooling the plurality of battery packs connected to the plurality of battery pack connection portions and the charging circuit portion with cooling air generated by the fan. Device. 3. The cooling airflow generated by the fan is separated by the guide section into a first cooling airflow flowing through the charging circuit section and a second cooling airflow guided to the plurality of battery pack connecting sections. 3. The charging device according to 1 or 2 . 4. The charging device according to any one of claims 1 to 3 , wherein said guide portion is made of a single member. 5. The charging device according to any one of claims 1 to 4 , wherein said second connecting portion is located off-center between said first and second side portions. The charging device according to any one of claims 1 to 5 , wherein the fan is arranged facing a third side portion connecting the first and second side portions. 7. The charging device of claim 6 , wherein the fan is located off-center between the first and second side portions. The charging device according to any one of claims 1 to 7, wherein the fan is located at a position avoiding between the battery pack connecting portions on the first side portion and the second side portion. 9. The guide portion located away from the fan has a shape that allows cooling air to flow more easily than the guide portion located closer to the fan. 3. Charging device according to paragraph. 10. The charging device according to any one of claims 1 to 9 , wherein said fan comprises a single fan. The charging device according to any one of claims 1 to 10 , further comprising a handle rotatably supported on the upper surface of said case. A recess for accommodating the handle is provided on the upper surface of the case,
In the guide portion, lower surfaces of the first air passage end portion and the first connecting portion that are not adjacent to the recess are higher than lower surfaces of the first air passage end portion and the first connecting portion that are adjacent to the recess. 12. The charging device of claim 11 in position.

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