Charging device

Abstract

The present invention provides a charging device, comprising a plurality of battery pack connection parts, and the charging device can perform appropriate charging while switching the battery pack to be charged. A microcomputer (90) can selectively execute a first mode and a second mode as control modes when a battery pack is connected to a plurality of battery pack connection parts (6a) to battery pack connection parts (6d). In the first mode, the battery pack to be charged is sequentially charged while switching before it is fully charged, and in the second mode, the battery pack to be charged is switched after it is fully charged, and the type or state of the battery pack to be charged is detected each time the switching is performed.

Description

Technical Field

[0001] The present invention relates to a charging device comprising a plurality of battery pack connecting parts. Background Art

[0002] In the following patent document 1, a charging device is capable of connecting four battery packs at the same time and can select a plurality of charging modes. In mode 1, charging is performed by switching the battery pack supplying the charging current every 2.5 hours, in mode 2, charging is performed by switching the battery pack supplying the charging current every 1 hour, and in mode 3, charging is performed by switching the battery pack supplying the charging current every 0.5 hours. With respect to the battery pack, the charge amount becomes 100% after 2.5 hours of charging, the charge amount becomes approximately 80% after 1 hour of charging, and the charge amount becomes approximately 60% after 0.5 hours of charging. The switching of the battery pack supplying the charging current may also be based on the charge amount.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Laid-Open No. 9-215217 Summary of the invention

[0006] Problems to be solved by the invention

[0007] Patent Document 1 shows the operation of the charging device when the rated voltages of the plurality of battery packs are the same and the charged capacities are also the same 0%, but does not disclose the case where the rated voltages or charged capacities of the plurality of battery packs are different from each other.

[0008] The present invention has been made in recognition of such a situation, and an object of the present invention is to provide a charging device including a plurality of battery pack connecting portions, the charging device being capable of performing appropriate charging while switching battery packs to be charged.

[0009] Technical means of solving problems

[0010] One embodiment of the present invention is a charging device. The charging device comprises:

[0011] A plurality of battery pack connections;

[0012] A charging circuit for charging the battery packs connected to the battery pack connecting parts;

[0013] A selection means for selecting a battery pack connection portion to be a supply destination of a charging current from the charging circuit; and

[0014] a control unit for controlling the charging circuit and the selection mechanism; and

[0015] The control unit can selectively execute the first mode and the second mode as control modes when the battery packs are connected to the plurality of battery pack connecting units.

[0016] In the first mode, the battery pack to be charged is sequentially charged while switching until it is fully charged, and in the second mode, the battery pack to be charged is switched after it is fully charged.

[0017] The control unit detects the type or state of the battery pack to be charged each time switching occurs.

[0018] The plurality of battery pack connecting portions include a first battery pack connecting portion for connecting the first battery pack and a second battery pack connecting portion for connecting the second battery pack.

[0019] In the first mode, the battery packs to be charged can be charged sequentially while switching the battery packs to be charged: charging of the first battery pack is started, and before the first battery pack is fully charged, charging of the first battery pack is stopped and charging of the second battery pack is started.

[0020] In the first mode, when charging a plurality of battery packs having different remaining capacities, the control unit may switch the battery pack to be charged without charging if the remaining capacity of the battery pack to be charged is higher than the remaining capacity of at least one other battery pack.

[0021] In the first mode, the control unit may derive the remaining capacity of each battery pack based on the relationship between the current output voltage of each battery pack and the output voltage when fully charged, and gradually increase the remaining capacity of the plurality of battery packs while making the remaining capacities the same.

[0022] The control unit may switch the battery pack to be charged without charging when an abnormality of the battery pack to be charged is detected.

[0023] In the second mode, the battery pack to be charged may be switched in the following manner: charging of the first battery pack is started, and after the first battery pack becomes fully charged, charging of the second battery pack is started.

[0024] A mode switching unit may be included for manually switching the control mode of the control unit between a first mode and a second mode.

[0025] In the first mode or the second mode, when the first battery pack is at a high temperature, the control unit may start charging the second battery pack without charging the first battery pack.

[0026] The control unit may start charging the first battery pack after charging the second battery pack, when the high temperature state of the first battery pack is resolved.

[0027] Furthermore, any combination of the above-described constituent elements, or embodiments in which the present invention is expressed in a method, a system, or the like may also be practiced as embodiments of the present invention.

[0028] Effects of the Invention

[0029] According to the present invention, there is provided a charging device including a plurality of battery pack connecting portions, and capable of performing appropriate charging while switching battery packs to be charged. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a perspective view of the charging device 1 according to the first embodiment of the present invention.

[0031] Figure 2 It is a perspective view of an air duct 20 of the charging device 1 .

[0032] Figure 3 It is a top view of the upper housing 4 of the charging device 1 .

[0033] Figure 4 It is a bottom view of the upper shell 4.

[0034] Figure 5 It is a diagram for explaining the internal structure of the charging device 1 .

[0035] Figure 6 yes Figure 5 VI-VI sectional view of the charging device 1, which is a sectional view of the battery pack 70 installed in the battery pack connecting portion 6d.

[0036] Figure 7 yes Figure 5 VII-VII section view.

[0037] Figure 8 It is a front view of the charging device 1 in a state where one battery pack 70 is mounted.

[0038] Fig. 9 is a circuit block diagram of the charging device 1 .

[0039] Fig.10 This is a flowchart of charging mode determination in the charging device 1 .

[0040] Fig.11 It is a flow chart of lighting up the charging mode display light emitting diode (LED) 102 in the charging device 1 .

[0041] Fig.12 : is a graph showing an example of the voltage value of the battery group to be charged that is switched in the first mode of the charging device 1 .

[0042] Fig.13 1 is a flowchart showing the flow of charging in the first mode of the charging device 1 .

[0043] Fig.14 1 and 2 are diagrams for explaining switching conditions of battery groups to be charged in each of the first mode and the second mode of the charging device 1 .

[0044] Fig.15 It is a bottom cross-sectional view of a charging device 1A according to a second embodiment of the present invention.

[0045] Fig.16 It is a plan cross-sectional view of the charging device 1A.

[0046] [Explanation of Reference Numerals]

[0047] 1. 1A: Charging device (charger)

[0048] 3: Shell (housing)

[0049] 3a: Upper surface

[0050] 3b: Lower surface

[0051] 3c~3f:Side part

[0052] 4: Upper shell

[0053] 5: Lower shell

[0054] 6a~6d: Battery pack connection

[0055] 7: Intake port (vent)

[0056] 8, 8A, 8B: Inhalation port (ventilation port)

[0057] 9, 9A, 9B: Exhaust port (vent)

[0058] 11: Plug insertion port (socket)

[0059] 12: Handle

[0060] 13: Charging mode switch (mode switching unit)

[0061] 14a~14d: Status display unit

[0062] 15: Guide rail

[0063] 16: Plug insertion port retainer (socket retainer)

[0064] 17: Power cord

[0065] 20: Air duct (guide part)

[0066] 21a-21d: End of the first air passage

[0067] 22: End of the second air duct

[0068] 23a to 23d: First connecting portion

[0069] 24: Second connection

[0070] 25a~25d: Connection part

[0071] 27: Through hole

[0072] 30: Rib

[0073] 31: Switch substrate

[0074] 34-35: Ribs

[0075] 37: Boss

[0076] 50: Main base board

[0077] 51: Transformer

[0078] 52~54: Heat sink

[0079] 55: Fan

[0080] 56: USB substrate

[0081] 57: USB connector

[0082] 58: FET (switching element)

[0083] 59: Air filter

[0084] 60: Rib

[0085] 61~69: Wiring

[0086] 70: Battery Pack

[0087] 71: Battery housing

[0088] 72: Secondary battery cell

[0089] 73: Intake port (vent)

[0090] 74: Exhaust port (vent)

[0091] 79: AC power supply

[0092] 80: Rectifier circuit

[0093] 81: Transformer

[0094] 82: Switching element

[0095] 83: Switch control circuit

[0096] 84: Rectification and smoothing circuit

[0097] 85: 12V power supply

[0098] 86: Fan control circuit

[0099] 87: Voltage feedback circuit

[0100] 88: Shunt resistor

[0101] 89: Current feedback circuit

[0102] 90: Microcomputer (control unit)

[0103] 91: Current detection circuit

[0104] 92: Overcharge detection circuit

[0105] 93a~93d:Relay

[0106] 94a~94d:Voltage detection circuit

[0107] 95a~95d: Overvoltage detection circuit

[0108] 96a~96d:Temperature detection circuit

[0109] 97a~97d:Battery pack identification circuit

[0110] 98: Transformer

[0111] 99: Switch control circuit

[0112] 100: Power

[0113] 101: Power

[0114] 102: Charging mode display LED

[0115] CA1: First cooling air

[0116] CA2: Second cooling air DETAILED DESCRIPTION

[0117] Below, while referring to the attached Figure 1 The preferred embodiments of the present invention are described in detail. Furthermore, the same or equivalent components, members, etc. shown in the drawings are marked with the same symbols, and repeated descriptions are appropriately omitted. In addition, the embodiments are illustrative and do not limit the invention, and all the features or their combinations described in the embodiments are not necessarily the essential contents of the invention.

[0118] (Implementation Method 1) Figure 1 to Figure 14A charging device 1 according to a first embodiment of the present invention will be described. Figure 1 The front and rear, up and down, and left and right directions of the charging device 1 are defined. The case (housing) 3 constituting the substantially rectangular outer frame of the charging device 1 is composed of an upper case 4 and a lower case 5. The upper case 4 and the lower case 5 are, for example, resin molded bodies.

[0119] The housing 3 has an upper surface portion 3a and a lower surface portion 3b ( Figure 6 and Figure 7 ), side 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 surface portion of the shell 3 and corresponds to the first side portion. The side portion 3d is the back portion of the shell 3 and corresponds to the second side portion. The side portion 3e is the right side portion of the shell 3. The side portion 3f is the left side portion of the shell 3 and corresponds to the third side portion. The side portions 3c and 3d face each other. The side portions 3e and 3f face each other. The lengths of the side portions 3c and 3d in the left-right direction are longer than the lengths of the side portions 3e and 3f in the front-back direction.

[0120] The handle 12 is supported to be rotatable on the upper surface portion 3a of the housing 3. Status display portions 14a to 14d are respectively provided at the four corners of the upper surface portion 3a of the housing 3. The status display portions 14a to 14d include light-emitting elements such as light-emitting diodes (LEDs). The status display portions 14a to 14d inform the operator of the charging status of the battery pack connected to the battery pack connection portion 6a to the battery pack connection portion 6d through their own lighting status. A charging mode switching switch 13 as a mode switching portion is provided in the front center of the upper surface portion 3a.

[0121] The front surface of the housing 3, i.e., the side surface 3c, is provided with a battery pack connection portion 6a and a battery pack connection portion 6b. Figure 5 As shown, a battery pack connection portion 6c and a battery pack connection portion 6d are provided on the back portion of the housing 3, i.e., the side portion 3d. The battery pack connection portions 6a to 6d respectively have a vent (air intake port) 7 and a pair of guide rail portions 15. The air intake port 7 is connected to the exhaust port of the battery pack connected to the battery pack connection portions 6a to 6d. The guide rail portion 15 extends in the up-down direction. The guide rail portion 15 serves as a guide when the battery pack is installed on the battery pack connection portions 6a to 6d. Furthermore, in the present embodiment, the vent 7 provided on the battery pack connection portions 6a to 6d is described as an air intake port, and the vent of the battery pack is described as an exhaust port, but the vent 7 may be described as an exhaust port, and the vent of the battery pack may be described as an air intake port.

[0122] A vent (intake port) 8 and a plug insertion port holder (socket holder) 16 are provided on the right side surface of the housing 3, i.e., the side surface 3e. The intake port 8 is located further back than the center of the side surface 3e and has multiple openings at the bottom. Two plug insertion ports (sockets) 11 are provided in the plug insertion port holder 16. Alternating current (AC) 100V is output to the plug insertion port 11. By inserting a power cord of an external electrical machine (not shown) into the plug insertion port 11, power can be supplied from the charging device 1 to the external electrical machine. As shown in FIG. Figure 5 As shown, a vent (exhaust port) 9 is provided on the left side face portion of the housing 3, that is, the side portion 3f. The exhaust port 9 is located further back than the center of the side portion 3f and has multiple openings at the bottom. Furthermore, in this embodiment, the vent 8 is described as an air intake port and the vent 9 is described as an exhaust port, but the vent 8 may be described as an exhaust port and the vent 9 may be described as an air intake port.

[0123] like Figure 5 and Figure 7 As shown, a main substrate 50 and a fan 55 are housed in the housing 3. The main substrate 50 is fixed to the lower surface of the lower housing 5 by screws or the like. The main substrate 50 is provided for mounting various parts constituting the charging circuit unit. The fan 55 is held near the exhaust port 9. The fan 55 is located further back than the center in the front-to-back direction of the housing 3, that is, the center between the side portion 3c and the side portion 3d. The fan 55 is an axial flow fan that draws air in the housing 3 and discharges it to the outside from the exhaust port 9. The fan 55 is a single fan that generates cooling air, and the cooling air cools the multiple battery packs connected to the battery pack connection portion 6a to the battery pack connection portion 6d and the charging circuit unit provided on the main substrate 50.

[0124] A transformer 51, heat sinks 52 to 54 for heat dissipation, a Universal Serial Bus (USB) substrate 56, a capacitor C, and a plurality of field effect transistors (FET) 58 as switching elements are provided on the main substrate 50. A USB connector 57 is provided on the USB substrate 56. The USB connector 57 opens on the left side (side portion 3f) of the lower housing 5. The power cord 17 is led out from the front of the right side (side portion 3e) of the housing 3 and is connected to an external AC power source such as a commercial power supply. Figure 5 and Figure 7 As shown, the air filter 59 is provided in the housing 3 and covers the air inlet 8. The air filter 59 prevents dust and the like from entering the housing 3 from the outside.

[0125] Wiring 61 to wiring 64 electrically connect the battery pack connection parts 6a to 6d and the main substrate 50. Wiring 65 electrically connects the switch substrate 31 fixed to the upper case 4 by screws or the like and the main substrate 50. Wiring 66 to wiring 69 electrically connects the status display parts 14a to 14d and the main substrate 50. The switch substrate 31 is provided with Figure 1 The charging mode switching switch 13 shown in the above is installed.

[0126] The air duct 20 is a guide portion that forms an air path between the fan 55 and the air inlet 7 of the battery pack connection portion 6a to the battery pack connection portion 6d. The air duct 20 is, for example, a resin molded body and includes a single member. Figure 2 As shown, the air duct 20 includes first air duct end portions 21a to 21d, a second air duct end portion 22, first connecting portions 23a to 23d, and a second connecting portion 24. The first air duct end portions 21a to 21d face (are close to) the air inlet 7 of the battery pack connecting portions 6a to 6d, respectively. The second air duct end portion 22 faces (is close to) the fan 55.

[0127] The first connecting portion 23a and the first connecting portion 23d extend approximately parallel to the front-to-back direction and connect the first air passage end portion 21a and the first air passage end portion 21d. The first connecting portion 23b and the first connecting portion 23c extend approximately parallel to the front-to-back direction and connect the first air passage end portion 21b and the first air passage end portion 21c. The second connecting portion 24 extends approximately parallel to the left-right direction and connects the confluence of the first connecting portion 23b and the first connecting portion 23c, the confluence of the first connecting portion 23a and the first connecting portion 23d, and the second air passage end portion 22. The second connecting portion 24 is located further back than the center between the side portions 3c and the side portions 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.

[0128] The first connection part 23a and the first connection part 23d are located closer to the fan 55 than the first connection part 23b and the first connection part 23c, that is, on the left. The curvature of the connection part 25a between the first connection part 23a and the second connection part 24 and the connection part 25d between the first connection part 23d and the second connection part 24 are relatively large. The curvature of the connection part 25b between the first connection part 23b and the second connection part 24 and the connection part 25c between the first connection part 23c and the second connection part 24 are relatively small (the curvature is smaller than that of the connection part 25a and the connection part 25d). As a result, the portion of the air duct 20 located away from the fan 55 has a smaller flow resistance than the portion located close to the fan 55, and the cooling air generated by the fan 55 is easily flowed, and the amount of cooling air passing through the air intake port 7 of the battery pack connection part 6a to the battery pack connection part 6d is nearly uniform.

[0129] like Figure 7 As shown, the lower end of the second air duct end 22 is located in the vertical direction within the existence range of the fan 55 and slightly above the center of the fan 55. Through the air duct 20, the cooling air generated by the fan 55 is separated into the first cooling air CA1 flowing through the charging circuit part and the second cooling air CA2 passing through the battery pack connection parts 6a to 6d.

[0130] A predetermined number of through holes 27 for screw fixing are provided on the lower surface of the air duct 20. Figure 4 As shown, on the lower surface of the upper shell 4, a predetermined number of bosses 37 for screw fixing are provided at positions corresponding to the through holes 27 of the air duct 20. The air duct 20 is fixed to the upper shell 4 by screw fixing or the like. On the lower surface of the upper shell 4, ribs 30, ribs 34, and ribs 35 are provided. The rib 30 is a rib for forming an air duct that is connected to the side portion of the air duct 20 and constitutes a part of the air duct. The rib 34 is provided to hold the fan 55 at a predetermined position. The rib 35 is provided above the second air duct end 22 of the air duct 20. The rib 35 guides the second cooling air CA2 in such a manner that it is efficiently sucked into the fan 55.

[0131] like Figure 6 As shown, a recess 38 for accommodating the handle 12 is provided on the upper surface portion 3a of the housing 3. The recess 38 exists from the vicinity of the center to the rear of the housing 3 in the front-to-back direction. The first connecting portion 23a of the air duct 20 is located at a position where the lower surface of the portion located further forward than the recess 38 (not close to the recess 38) and the first air passage end 21a is higher than the lower surface of the portion located directly below the recess 38 (close to the recess 38) or the lower surface of the first connecting portion 23d and the first air passage end 21d. Similarly, the first connecting portion 23b is located at a position where the lower surface of the portion located further forward than the recess 38 and the first air passage end 21b is higher than the lower surface of the portion located directly below the recess 38 or the lower surface of the first connecting portion 23c and the first air passage end 21c. The reason for this is to suppress the difference in the ease of flow of the cooling air caused by the presence of the recess 38.

[0132] like Figure 6As shown, the battery pack 70 includes a battery case 71 and a secondary battery cell 72. A plurality of secondary battery cells 72 are accommodated and retained in the battery case 71. The battery case 71 is provided with an air intake port (vent) 73 and an exhaust port (vent) 74. The exhaust port 74 is connected to the air intake port 7 of the charging device 1. The battery pack 70 is fixed to the charging device 1 by being mounted on any one of the battery pack connection parts 6a to the battery pack connection parts 6d, and an electrical connection with the charging device 1 (contact between the terminals) is established, thereby becoming a state in which charging can be performed by the charging device 1. Since the air intake port (vent) 73 faces downward, dust and the like can be suppressed from entering the battery case 71.

[0133] The flow of cooling air generated when the fan 55 is driven will be described. Figure 7 As shown, the first cooling air CA1 is taken into the housing 3 through the air inlet 8 and the air filter 59 of the housing 3, cools the components on the main substrate 50, and is sucked by the fan 55 and discharged to the outside of the housing 3 through the exhaust port 9. Figure 6 As shown, the second cooling air CA2 is taken into the battery pack 70 from the air intake ports 73 of each battery pack 70 connected to the battery pack connecting portions 6a to 6d to cool the components in the battery pack 70, and is taken into the housing 3 from the air intake ports 7 of the housing 3 to be guided by the air duct 20 as shown in FIG. Figure 7 As shown, the air is sucked in by the fan 55 and discharged from the exhaust port 9 to the outside of the housing 3.

[0134] Fig. 9 : is a circuit block diagram of the charging device 1. 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 a FET are provided between the output terminals of the rectifier circuit 80. The on / off of the switching element 82 is controlled by a switch control circuit 83. The rectifier and smoothing circuit 84 rectifies and smoothes the output current of the secondary side of the transformer 81. The transformer 81, the switching element 82 and the rectifier and smoothing circuit 84 constitute a charging circuit. The 12V power supply 85 converts the output voltage of the rectifier and smoothing circuit 84 into the operating voltage of the fan 55 (for example, direct current (DC) 12V). The fan control circuit 86 controls the drive of the fan 55.

[0135] The voltage feedback circuit 87 detects the output voltage of the rectifying and smoothing circuit 84 and feeds it back to the switch control circuit 83. The shunt resistor 88 is provided in the path of the output current (charging current) from the rectifying and smoothing circuit 84 to the battery pack connection part 6a to the battery pack connection part 6d. The current feedback circuit 89 detects the charging current through the voltage across the shunt resistor 88 and feeds it back to the switch control circuit 83. The current detection circuit 91 detects the charging current through 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 according to the control of the microcomputer 90.

[0136] The microcomputer (microcontroller) 90 functions as a control unit. The microcomputer 90 controls the switch control circuit 83, and controls the output voltage and output current of the rectification and smoothing circuit 84 to be appropriate values ​​corresponding to the state or type of the battery pack to be charged (the battery pack that is currently supplied with charging current among the battery packs connected to the battery pack connection parts 6a to 6d). In addition, the microcomputer 90 controls the fan control circuit 86, and controls the driving of the fan 55.

[0137] The transformer 98 and the switch control circuit 99 are provided between the output terminals of the rectifier circuit 80. The power supplies 100 and 101 are provided on the secondary side of the transformer 98. The power supply 100 supplies the operating voltage of the switch control circuit 83. The power supply 101 supplies the operating voltage (for example, DC 5V) of the microcomputer 90. With regard to the connection between the voltage feedback circuit 87, the current feedback circuit 89, the microcomputer 90, the power supply 100 and 101, and the switch control circuit 83, the insulation between the primary side and the secondary side of the transformer 81 and the transformer 98 can be ensured by using a photocoupler or the like.

[0138] The C+ terminal and the C- terminal provided at the battery pack connection portion 6a to the battery pack connection portion 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 of the battery pack (rated voltage, etc.) from the battery pack. The battery pack connection portion 6a corresponds to port 1, the battery pack connection portion 6b corresponds to port 2, the battery pack connection portion 6c corresponds to port 3, and the battery pack connection portion 6d corresponds to port 4.

[0139] Diodes D1 to D4 are respectively provided in the current path from the rectifying and smoothing circuit 84 to the battery pack connection part 6a to the battery pack connection part 6d to prevent the reverse flow of current. Relays 93a to 93d as selection mechanisms are respectively provided in the current path from the rectifying and smoothing circuit 84 to the battery pack connection part 6a to the battery pack connection part 6d. Relays 93a to 93d are selectively turned on by the control of the microcomputer 90 according to whether the battery pack connected to any one of the battery pack connection parts 6a to the battery pack connection part 6d is a battery pack to be charged. Voltage detection circuits 94a to 94d detect the voltage of each battery pack connected to the battery pack connection part 6a to the battery pack connection part 6d and feed it back to the microcomputer 90. Overvoltage detection circuits 95a to 95d detect whether each battery pack connected to the battery pack connection part 6a to the battery pack connection part 6d is overvoltage and feed it back to the microcomputer 90. The temperature detection circuits 96a to 96d detect the temperature of each battery pack connected to the battery pack connection parts 6a to 6d, and feed back to the microcomputer 90. The battery pack identification circuits 97a to 97d detect the type of each battery pack connected to the battery pack connection parts 6a to 6d, and feed back to the microcomputer 90. The microcomputer 90 detects the type (rated voltage, etc.) and state (voltage or temperature) of the battery pack to be charged each time the battery pack to be charged is switched.

[0140] Fig.10Flow chart of charging mode discrimination in the charging device 1. The microcomputer 90 displays charging standby on the status display section 14a to the status display section 14d (S1). When a battery pack is connected to at least one of the battery pack connection sections 6a to 6d (S2 is (YES)), the microcomputer 90 checks the temperature of the connected battery pack, and if it is not a specified temperature, for example, above 50°C (S3 is (NO)), the type or state of the battery pack is discriminated (S4). The step S4 is performed every time the charging of the battery pack is started regardless of the charging mode described later. That is, it is performed every time the battery pack to be charged is switched. Thus, the microcomputer 90 can correctly grasp the type or state of the battery pack before charging, and can perform correct charging corresponding 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 (S5 is "normal"), the microcomputer 90 determines that the control of charging in the order of port numbers is performed (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 the control of charging in order of voltage from low to high is performed (S7), and starts charging (S8). In step S3, when the temperature of the battery pack is a specified temperature, for example, 50°C or above (S3 is (YES)), the microcomputer 90 performs a high temperature standby display on the status display section 14a to the status display section 14d corresponding to the battery pack connection section 6a to the battery pack connection section 6d to which the battery pack is connected (S9), and drives the fan 55 (S10). In the case where there is only one battery pack connected, when it is determined to be high temperature in step S3, steps S9 and S10 are executed until the high temperature state is released. On the other hand, in the state where multiple battery packs are connected, it is also considered that one battery pack is at a high temperature and the other battery packs are not at a high temperature. In the above case, in step S3, even if there is a battery pack at a high temperature, charging cannot be started. Therefore, it can also be set as follows: in step S3, the temperatures of all connected battery packs are detected, and when there is a battery pack that is not at a high temperature, the process proceeds to step S4, and only the battery pack that is not at a high temperature can be charged. After the high temperature state is released, charging is performed in the selected charging mode.

[0141] Fig.11This is a flowchart of lighting the charging mode display LED 102 in the charging device 1. When the charging mode switching switch 13 is pressed (Yes (YES) in S11), the microcomputer 90 switches the charging mode between the first mode (simultaneous charging mode) and the second mode (normal mode), and if the mode after switching is not the simultaneous charging mode (No (NO) in S12), the charging mode display LED 102 is lit (S13). If the mode after switching is the simultaneous charging mode (Yes (YES) in S12), the microcomputer 90 turns off the charging mode display LED 102 (S14).

[0142] Fig.12 This is a graph showing an example of the voltage value of the battery pack to be charged in the first mode (simultaneous charging mode) of the charging device 1. In the simultaneous charging mode, all the battery packs are first charged to 3.8V per secondary battery cell while switching the battery pack to be charged. Thereafter, all the battery packs are charged to 3.95V per secondary battery cell while switching the battery pack to be charged. Similarly, all the battery packs are charged in stages to 4.1V and 4.17V per secondary battery cell.

[0143] Fig.13It is a flowchart showing the charging process in the first mode of the charging device 1. The microcomputer 90 selects the battery group with the lowest voltage (the battery group with the lowest remaining capacity rate (or remaining capacity)) as the battery group to be charged, and distinguishes (detects) the type or state of the battery group. Then, the target voltage is set to 3.8V for each secondary battery cell, and the battery group is continuously charged (S22) until the voltage of the battery group to be charged reaches 3.8V for each secondary battery cell (S21's NO). When the voltage of the battery group to be charged reaches 3.8V for each secondary battery cell (S21's YES), the microcomputer 90 switches the battery group to be charged to the battery group with the lowest voltage among the remaining battery groups (S23). The microcomputer 90 distinguishes the type or state of the battery group before charging the battery group each time it switches. In this way, the type or state of the battery group to be charged can be correctly grasped, and correct charging corresponding to the type or state of the battery group can be performed. The microcomputer 90 switches the battery group to be charged each time the voltage of each battery group reaches 3.8V per secondary battery cell, and when the voltage of all battery groups reaches 3.8V per secondary battery cell (S24 is (YES)), the target voltage is switched to 3.95V per secondary battery cell (S25). The microcomputer 90 charges while switching the battery group to be charged, and when the voltage of all battery groups reaches 3.95V per secondary battery cell (S26 is (YES)), the target voltage is switched to 4.1V per secondary battery cell (S27). The microcomputer 90 charges while switching the battery group to be charged, and when the voltage of all battery groups reaches 4.1V per secondary battery cell (S29 is (YES)), the target voltage is switched to 4.17V per secondary battery cell (S30). The microcomputer 90 charges while switching the battery pack to be charged. When the voltage of all the battery packs reaches 4.17V for each secondary battery cell (S31 is (YES)), the charging completion display is displayed on the status display unit 14a to the status display unit 14d (S32). Furthermore, 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, above 50°C), switches to a battery pack with a lower voltage after the battery pack. Then, after the voltage of the battery pack reaches the target voltage, the battery pack that was skipped due to the high temperature can be charged. However, if the high temperature state continues, other battery packs can be charged, and after the high temperature state is released, the charging of the battery pack can be started. In addition, Fig.12 and Fig.13The voltage of each secondary battery cell 72 is shown as the target voltage, but it can also be charged in stages 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, first, charge until the voltage of the battery pack is 19V (3.8V×5 cells), and then charge in stages to 19.75V, 20.5V, and 20.85V. Each time the battery pack to be charged is switched, the type or state of the battery pack is judged, thereby determining whether the same battery pack is connected. In the case where the type of the battery pack is only judged once during the period until the charging of all connected battery packs is completed, when a different battery pack is replaced midway, the battery pack inherits the information of the previously connected battery pack, resulting in an undesirable situation in which charging is terminated without being fully charged. Therefore, in this embodiment, the charging can be reliably terminated by always judging the type of the battery pack before charging starts (at each switch).

[0144] The microcomputer 90 can derive the remaining capacity rate of each battery pack based on the relationship between the current output voltage of each battery pack and the output voltage when fully charged. By judging the switching of the battery pack to be charged based on the remaining capacity rate, the battery pack to be charged can be switched appropriately even when multiple battery packs with different rated voltages are connected. In the first mode, when charging multiple battery packs with different remaining capacity rates, the microcomputer 90 switches the battery pack to be charged without charging when the remaining capacity rate of the battery pack to be charged is higher than the remaining capacity rate of at least one other battery pack. When the microcomputer 90 detects an abnormality (high temperature abnormality, etc.) of the battery pack to be charged, it switches the battery pack to be charged without charging.

[0145] Fig.141 is an explanatory diagram of the switching conditions of the battery group to be charged in each of the first mode and the second mode of the charging device 1. The second mode (normal mode) is a mode in which the battery groups are charged in the order of the port numbers, and after the battery group to be charged is fully charged, the battery group with the next port number is switched. In the normal mode, when the battery group to be charged is in the high temperature standby state, the battery group is skipped and the battery group with the next port number is charged as the battery group to be charged. If the high temperature standby state is released, after the charging of the battery group being charged is completed, the battery group is charged as the battery group to be charged. Alternatively, after the charging of all battery groups other than the battery group is completed, the battery group is charged as the battery group to be charged. When the battery group being charged is unplugged, the battery group with the next port number can be charged. Furthermore, when a battery group is connected in the middle, after the charging of the battery group being charged is completed, it can be charged in the order of the port numbers. For example, when charging the battery group with port number 3, if a battery group is connected to port number 2, after the charging of the battery group with port number 3 is completed, the newly connected battery group with port number 2 is charged. On the other hand, if a battery pack is connected to port number 4, it is sufficient to charge in the order of the port numbers. Furthermore, in the second mode, the control from the start of charging of a battery pack to the completion of charging is a well-known technique that is usually performed. That is, the control is as follows: when the battery pack is a lithium battery, charging starts by constant current charging, and after the voltage of the battery pack (or the voltage of the secondary battery cell) reaches a specified value, it is switched to constant voltage charging, and after the charging current drops to a specified current, charging is stopped as full charging. In the first mode (simultaneous charging mode), charging is performed from the battery pack with a low voltage (remaining capacity rate), and the voltages (remaining capacity rates) of multiple battery packs are made consistent while being increased in stages. When the battery pack to be charged is in a high-temperature standby state, the battery packs other than the battery pack are charged in order from low to high voltage. When a part of the battery pack is unplugged midway, the remaining battery packs are charged in order from low to high voltage. When a new battery pack is connected midway, all battery packs including the battery pack are charged in order from low to high voltage. In the first mode, even if the rated voltages of the connected battery packs are different, Fig.14For example, if there is a battery pack with a low rated voltage, the battery pack is charged earlier than other battery packs. After that, even in any mode, it is sufficient to continue charging the battery pack that has not been fully charged. Therefore, there is no problem even if multiple battery packs with different rated voltages are connected. In addition, by detecting the type and state of the battery pack, the rated voltage and the remaining capacity rate (the ratio of the remaining capacity to the rated voltage) of the battery pack can be calculated. Therefore, by charging from the battery pack with a low remaining capacity rate, even if the rated voltages are different, the charging can be completed at approximately the same time.

[0146] According to this embodiment, the following effects can be achieved.

[0147] (1) Since the cooling air generated by the fan 55 is separated into the first cooling air CA1 flowing through the charging circuit section and the second cooling air CA2 passing through the battery pack connecting sections 6a to 6d through the air duct 20, the charging circuit section can be cooled by the fan 55, and the plurality of battery packs connected to the charging device 1 can also be cooled. Here, if the fan 55 is a single fan, the cost can be reduced compared to the case where a plurality of cooling fans are provided, and the wiring can be simplified, and both the charging circuit section and the plurality of battery packs can be cooled efficiently.

[0148] (2) The air duct 20 is a single component that only needs to be screwed to the upper housing 4, thereby suppressing the increase in the cost, number of parts, and manufacturing man-hours required to separate the cooling air generated by the fan 55 into the first cooling air CA1 and the second cooling air CA2. In addition, the air duct 20 also has the function of guiding dust or water entering from the air inlet 7 to the fan 55, which also helps to prevent dust and water inside the housing 3 and outside the air duct 20.

[0149] (3) An air intake port 8 and a plug insertion port 11 for the first cooling air CA1 are provided on the side portion 3e of the shell 3 where the battery pack connection portion 6a to the battery pack connection portion 6d are not provided. In addition, an air exhaust port 9 and a USB connector 57 are provided on the side portion 3f where the battery pack connection portion 6a to the battery pack connection portion 6d are not provided, so that the layout efficiency is good.

[0150] (4) The curvature of the connection portion 25b and the connection portion 25c located away from the fan 55 is made smaller than the curvature of the connection portion 25a and the connection portion 25d located near the fan 55, so that the amount of cooling air passing through the air intake port 7 of the battery pack connection portion 6a to the battery pack connection portion 6d can be made nearly uniform compared to the case where the two curvatures are equal. In addition, since the fan 55 is arranged at the end portion away from the central portion of the housing 3, the arrangement area of ​​the main substrate 50 can be ensured.

[0151] (5) In the first mode (simultaneous charging mode), the microcomputer 90 determines the switching of the battery pack to be charged based on the remaining capacity of each of the plurality of battery packs, thereby appropriately switching the battery pack to be charged even when a plurality of battery packs having different rated voltages are connected. In addition, when a battery pack in a high temperature state is connected, the other battery packs are charged until the high temperature state is released, thereby efficiently charging the plurality of battery packs.

[0152] (6) In the first mode (simultaneous charging mode), the microcomputer 90 sequentially charges the battery packs starting from the battery packs with the lowest remaining capacity, and thus can charge the battery packs while quickly equalizing the variations in the remaining capacities of the plurality of battery packs.

[0153] (Implementation Method 2) Fig.15 It is a bottom cross-sectional view of a charging device 1A according to a second embodiment of the present invention. Fig.16 1 is a plan view of a charging device 1A. The following description will focus on the differences from the first embodiment. The charging device 1A has a fan 55A, an air intake port (vent) 8A, an exhaust port (vent) 9A, and a main substrate 50A for the battery pack connection portion 6a and the battery pack connection portion 6d, and has a fan 55B, an air intake port (vent) 8B, an exhaust port (vent) 9B, and a main substrate 50B for the battery pack connection portion 6b and the battery pack connection portion 6c.

[0154] The lower housing 5 is provided with a rib 60 that divides the housing 3 into two (roughly two equal parts) left and right. The fan 55A, the air intake port 8A, the air exhaust port 9A, and the main substrate 50A are provided on the left side of the rib 60. The fan 55B, the air intake port 8B, the air exhaust port 9B, and the main substrate 50B are provided on the right side of the rib 60. The air intake port 8A opens on the lower surface of the right front portion of the left side region of the rib 60 of the housing 3. The air intake port 8B opens on the lower surface of the left front portion of the right side region of the rib 60 of the housing 3. The fan 55A is provided at the lower portion of the left rear portion of the housing 3. The fan 55B is provided at the lower portion of the right rear portion of the housing 3. The air exhaust port 9A is provided at the lower rear portion of the left side surface of the housing 3. The air exhaust port 9B is provided at the lower rear portion of the right side surface of the housing 3. The main substrate 50A is fixed to the lower surface of the left side region of the rib 60 of the housing 3 by screw fixing or the like. The main substrate 50A is provided with a charging circuit unit for charging the battery pack connected to the battery pack connection portion 6a and the battery pack connection portion 6d. The main substrate 50B is fixed to the lower surface of the right side area of ​​the rib 60 of the housing 3 by screw fixing or the like. The main substrate 50B is provided with a charging circuit unit for charging the battery pack connected to the battery pack connection portion 6b and the battery pack connection portion 6c.

[0155] The air duct 20A and the air duct 20B serving as guide portions are fixed to the upper housing 4 by screw fixing or the like. The air duct 20A forms an air path between the air intake ports of the battery pack connection portion 6a and the battery pack connection portion 6d and the fan 55A. The air duct 20B serving as a guide portion forms an air path between the air intake ports of the battery pack connection portion 6b and the battery pack connection portion 6c and the fan 55B. In the air duct 20A, the first air duct end portion 21a facing the air intake port of the battery pack connection portion 6a is wider than the first air duct end portion 21d facing the battery pack connection portion 6d. In addition, the curvature of the connection portion 25a between the first connecting portion 23a and the second connecting portion 24A is smaller than the curvature of the connection portion 25d between the first connecting portion 23d and the second connecting portion 24A. The reason for these structures is that the first air passage end 21a is farther from the fan 55A than the first air passage end 21d, so that the amount of cooling air passing through the air intakes of the battery pack connection part 6a and the battery pack connection part 6d is nearly uniform. The air duct 20B is symmetrical with the air duct 20A.

[0156] The other aspects of this embodiment are the same as those of Embodiment 1. According to this embodiment, although two fans 55A and 55B are required, since one fan is used to cool two battery packs and one charging circuit unit, the cost can be reduced compared to the case where one fan is used to cool one battery pack and one charging circuit unit or the case where one fan is used to cool two battery packs, and the wiring can also be simplified.

[0157] Although the present invention has been described above by taking the embodiments as examples, it is apparent to those skilled in the art that various modifications can be made to the components or processes of the embodiments within the scope of the claims.

[0158] The number of battery packs that can be connected simultaneously in the charging device of the present invention is not limited to four, and can be any number.

Claims

1. A charging device, comprising: A plurality of battery pack connection parts, wherein the plurality of battery pack connection parts include a first battery pack connection part for connecting a first battery pack and a second battery pack connection part for connecting a second battery pack; A charging circuit for charging the battery packs connected to the battery pack connecting parts; A selection means for selecting a battery pack connection portion to be a supply destination of a charging current from the charging circuit; and a control unit for controlling the charging circuit and the selection mechanism; and The control unit is capable of selectively executing a first mode and a second mode as control modes when a plurality of battery pack connecting units are connected to battery packs. In the first mode, charging of the first battery pack with the lowest voltage is started, and charging of the first battery pack is stopped before the first battery pack is fully charged, and charging of the second battery pack with the lowest voltage among the remaining battery packs is started, and the battery packs to be charged are charged in order from low to high voltage while switching the battery packs to be charged. In the second mode, the first battery pack is charged, and after the first battery pack is fully charged, the second battery pack is charged, and the battery packs to be charged are charged sequentially while switching. The control unit detects the type or state of the battery pack to be charged each time the battery pack is switched. When the first battery pack is connected to the first battery pack connection part and the second battery pack is connected to the second battery pack connection part to execute the first mode, in a case where another battery pack different from the first battery pack and the second battery pack is newly connected to another battery pack connection part among the multiple battery pack connection parts that is different from the first battery pack connection part and the second battery pack connection part, all battery packs including the first battery pack, the second battery pack and the newly connected another battery pack are charged sequentially in the first mode.

2. The charging device according to claim 1, wherein: In the first mode, when charging a plurality of battery packs having different remaining capacities, the control unit switches the battery pack to be charged without charging if the remaining capacity of the battery pack to be charged is higher than the remaining capacity of at least one other battery pack.

3. The charging device according to claim 1, wherein: In the first mode, the control unit derives the remaining capacity of each battery pack based on the relationship between the current output voltage of each battery pack and the output voltage when fully charged, and gradually increases the remaining capacity of the plurality of battery packs while making the remaining capacities the same.

4. The charging device according to claim 1, wherein: The control unit switches the battery pack to be charged without charging when an abnormality of the battery pack to be charged is detected. 5 . The charging device according to claim 1 , comprising a mode switching unit configured to manually switch a control mode of the control unit between a first mode and a second mode.

6. The charging device according to claim 1, wherein: In the first mode or the second mode, when the first battery pack is at a high temperature, the control unit does not charge the first battery pack and starts charging the second battery pack.

7. The charging device according to claim 6, wherein: When the high temperature state of the first battery pack is released, the control unit starts charging the first battery pack after charging the second battery pack.

8. The charging device according to claim 1, wherein: The control unit is configured to enable charging even when the battery packs connected to the plurality of battery pack connecting units have different rated voltages.

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