POWER SUPPLY DEVICE

A power supply device comprising: a plurality of battery units each having a protective unit, an output voltage from the plurality of battery units being configured to energize an electric power tool; and a drive-limiting unit provided in a current path of the battery unit of each row, wherein each protective unit stops energization from the battery unit of its row by the drive-limiting unit provided in the current path of the battery unit of its row, when the battery unit of its row has an error.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present invention will now be described with reference to the accompanying drawings. Note that all same or similar constituents or members in all drawings are given similar reference numerals or symbols, so as to avoid repetitive explanation. Note also that the embodiment does not intend to limit the scope of the present invention but exemplify the invention. All of the features and the combinations thereof described in the embodiment are not necessarily essential to the invention.

FIG. 1is a diagram illustrating the whole configuration of a power supply system employing a power supply device1according to an embodiment of the present invention.FIG. 2is a front view of a connection terminal section for connecting the power supply device1with an external device. The connection terminal section illustrated in the drawing is installed at a bottom surface of a housing11of the power supply device1inFIG. 1, for example.FIG. 3is a circuit diagram of the power supply device1in the housing11.FIG. 4is an enlarged front view of a main discharge terminal21inFIG. 2.FIG. 5is an enlarged front view of a low-voltage adaptor81and a high-voltage adapter91which are connected to the main discharge terminal21.FIG. 6is an internal circuit diagram of the high-voltage adaptor91.FIG. 7is an internal circuit diagram illustrating one example of the low-voltage adaptor81.FIG. 8is an internal circuit diagram illustrating another example of the low-voltage adaptor81.

As illustrated inFIG. 1, the power supply device1is a back-pack type, and includes a housing11for receiving or housing battery packs31a,31b(FIG. 3) as a battery unit, the housing11being attached with a shoulder belt (harness)6, a shoulder belt fixing belt10for stably fixing the shoulder belt6on a chest of a body, a back contact pad9functioning as a back contact portion, left and right waist contact pads2, and a waist contact pad fixing belt5for stably fixing the left and right waist contact pads2on a waist of the body. Herein, the back contact pad9and the left and right waist contact pads2may be configured by one constitutional component, that is, may be a so-called back pack type.

As illustrated inFIG. 2, the power supply device1includes a power switch20, the main discharge terminal21, a charge terminal28, informing units27a,27b,such as LED, a mode switching switch26, an optional function connection terminal23(discharge terminal for option), and a general-purpose output socket24(transformation output terminal). The power switch20is an on/off switch of the power supply device1. The main discharge terminal21is a terminal to be selectively connected to a low-voltage electric power tool7aor a high-voltage electric power tool7b,which are illustrated inFIG. 1. The charge terminal28is a terminal to be connected to a charger (not illustrated) to charge the battery packs31a,31bof the power supply device1. The informing units27a,27b,such as LED, inform a user of a state of the battery packs31a,31b,and, for example, are turned on or off according to the presence or absence of the output from the battery packs31a,31b. The mode switching switch26switches between stopping or maintaining the output of the optional function connection terminal23and the general-purpose output socket24if a protective circuit for any one of the battery packs31a,31bis operated (e.g., residual capacity shortage). The optional function connection terminal23is provided to be connected to an electric apparatus separate from the low-voltage electric power tool7aor the high-voltage electric power tool7b.The general-purpose output socket24is a terminal capable of connecting a 12V apparatus, such as vehicular equipments, or a compact electronic apparatus which is driven by a general-purpose power supply terminal such as Universal Serial Bus (USB).

As illustrated inFIG. 3, the respective battery packs31aand31bincludes a plurality of battery cells33which are connected in series to each other to generate a rated voltage of, for example, 18V (five battery cells are connected in series to each other if a single cell is 3.6V), in which the battery cells33connected in series to each other are connected in parallel with each other to increase its capacity. The battery packs31aand31bare equipped with protective substrate sets39a,39bhaving a function of monitoring errors, such as charge, overcharge, over discharge, or over current. As illustrated inFIGS. 4 and 6, positive electrodes34a,34band negative electrodes35a,35bof the battery packs31a,31bare led to the main discharge terminal21by internal wiring illustrated inFIG. 3, and face the bottom surface of the housing11, for example, as a connection hole. For example, the protective substrate sets39a,39bare configured to output a drive-limiting signal of a high level to signal output terminals36a,36b,at the errors, such as over discharge, of the battery packs36a,36b,and to output a signal of a low level to the signal output terminals36a,36bduring normal operation. However, the signals to be output to the signal output terminals36a,36bmay be opposite thereto.

As illustrated inFIG. 1, the low-voltage adaptor81is connected to the low-voltage electric power tool7aby an adaptor cable103aand a low-voltage tool-side adaptor85. Further, the high-voltage adaptor91is connected to the high-voltage electric power tool7bby an adaptor cable103band a high-voltage tool-side adaptor95. As illustrated inFIG. 5, the low-voltage adaptor81and the high-voltage adaptor91have terminals51ato53aand51b(pin shape) to53bconnected to the respective terminals (connection hole) of the main discharge terminal21.

As illustrated inFIG. 6, in the high-voltage adaptor91(e.g., for 36V), the positive electrode34aof the battery pack31ais connected to a positive output terminal92, and the negative electrode35bof the battery pack31bis connected to a negative output terminal93, and the positive electrode34bof the battery pack31bis connected to the negative electrode35aof the battery pack31a.In addition, the drive-limiting signal output terminals36a,36bof the protective substrate sets39a,39bare used as an input of an OR gate901, and an output terminal of the OR gate901is connected to an LD output terminal94. Accordingly, a composite voltage (36V) formed by the series connection of the battery packs31a,31bis output from the high-voltage adaptor91, and a logical sum of the drive-limiting signals of the protective substrate sets39a,39bis also output therefrom. That is, when the battery packs31a,31bare connected in series to each other, the drive-liming signal is output to the electric power tool side if at least one of the battery packs31a,31bhas an error. In this instance, the protective substrate sets39a,39bsending the drive-limiting signal may directly interrupt the current output from the battery packs31a,31b. If there is no such a function, the electric power tool side receiving the drive-limiting signal may interrupt the current from the battery packs31a,31b.

As illustrated inFIG. 7, in the low-voltage adaptor81(e.g., for 18V), the positive electrodes34a,34bof the battery packs31a,31bare connected to a positive output terminal82, and the negative electrodes35a,35bare connected to a negative output terminal83. In addition, the drive-limiting signal output terminals36a,36bof the protective substrate sets39a,39bare used as an input of an AND gate801, and an output terminal of the AND gate801is connected to an LD output terminal84. Accordingly, a composite voltage (18V) formed by the parallel connection of the battery packs31a,31bis output from the low-voltage adaptor81, and a logical product of the drive-limiting signals of the protective substrate sets39a,39bis also output therefrom. That is, when the battery packs31a,31bare connected in parallel with each other, the drive-limiting signal is output to the electric power tool side if both the battery packs31a,31bhave errors. When only one of the battery packs31a,31bhas an error, the electric power tool is continuously energized from the other normal battery pack. In this instance, the protective substrate, which sends the drive-limiting signal, of the protective substrate sets39a,39bmay directly interrupt the current output from one battery pack. If there is no such a function, as illustrated inFIG. 8, the low-voltage adaptor81is provided with drive-limiting switches (switching element)802,803, and the drive-limiting switches802,803may be turned off by the drive-limiting signal.

As described above, the power supply device1supplies low voltages (18V) in two lines to the main discharge terminal21connecting the low-voltage adaptor81and the high-voltage adaptor91as the output, and transforms it into a low voltage (18V) or a high voltage (36V) in one line by a wire connection (internal circuit) of the low-voltage adaptor81or the high-voltage adaptor91to supply it to the low-voltage electric power tool7aor the high-voltage electric power tool7b.That is, the power supply device1can output two kinds of voltages, the low voltage (18V) and the high voltage (36V), from the main discharge terminal21only by changing the adaptor. As an example, if the battery packs31a,31bare 18V, 5 Ah rating, respectively, the capacity becomes 10 Ah when the low-voltage adaptor81(18V) is used, while the capacity becomes 5 Ah when the high-voltage adaptor91(36V) is used.

As illustrated inFIG. 1, the waist contact pad2is equipped with a fan3, which is an optional equipment, functioning as a cooling unit for cooling the body of the worker. The fan3is energized by, for example, 18V, from the battery packs31a,31bvia the optional function connection terminal23. The fan23is configured to receive the air from the exterior and to discharge the heat stayed at a back portion of the worker. The worker can turn on or off the fan3using a fan power switch4which is installed on the waist contact pad2. This can lead to decrease the discomfort of the worker due to the heat generated from the battery packs31a,31b.The fan3may be installed in, for example, the back contact pad9at the upper portion of the housing11. As the cooling unit, a Peltier element may be installed in, for example, the back contact pad9, instead of the fan3or in addition to the fan3. As the Peltier element is disposed between the back of the worker and the housing11receiving the battery packs31a,31btherein so that the back side becomes a heat absorbing surface (cooling surface), it can decrease the discomfort of the worker due to the heat generated from the battery packs31a,31b. Further, it can employ a configuration of heating the worker in a cold climate region by installing the Peltier element or the electrically-heated wire between the back of the worker and the housing11receiving the battery packs31a,31bso that the back side becomes a heating surface.

As illustrated inFIG. 1, the power supply device1is connected to a small electric apparatus8for general-purpose use. As illustrated inFIG. 3, the output voltage of a transformer circuit25which steps down the voltage (herein, 18V in voltage by the parallel connection) of the battery packs31aand31bis output from the general-purpose output socket24, and the electric apparatus8for general-purpose use is energized by the battery packs31aand31bvia the output socket24. The electric apparatus8for general-purpose use is, for example, a 12V-type vehicular equipment which can be commercially available at a low price, or a USB, and includes a cleaner, an LED light, polisher, a cell phone, a general-purpose inverter, etc. In the case where the 12V-type vehicular equipment is used, if an electric power source is taken from a vehicle, it may lead to shortage of the battery unless an engine of the vehicle is started. Further, since a cable for the 12V-type vehicular equipment is short, there is inconvenience such as it is difficult to do work. If the power supply device1is provided with the general-purpose output socket24to use the 12V-type vehicular equipment, as illustrated in this embodiment, the above-described problem can be solved, and it can be useful as a power source for emergency. For example, if the battery packs31aand31bare charged, the cell phone or the like can be charged or supplied with electricity, or the general-purpose inverter can be driven to supply 100V.

In this instance, the fan3and the small electric apparatus8for general-purpose use can be switched by the mode switching switch26between an optional power saving mode, in which if either of the battery packs31a,31bhas an error or is empty, it is turned off, and an optional non-power saving mode, in which if both the battery packs31a,31bhave an error or is empty, it is turned off. In the optional power saving mode, an output signal (logical sum of the drive-limiting signals of the protective substrate sets39a,39b) of the OR gate261is output to a mode control section29and the transformer circuit25. In the optional non-power saving mode, an output signal (logical product of the drive-limiting signals of the protective substrate sets39a,39b) of the AND gate262is output to the mode control section29and the transformer circuit25. In the optional non-power saving mode, when only either of the battery packs31a,31bhas an error, the fan3and the small electric apparatus8for general-purpose use are continuously energized from the other normal battery pack (the mode control section29and the transformer circuit25continuously output the voltage to the optional function connection terminal23and the general-purpose output socket24). In this instance, one of the protective substrate sets39a,39bwhich emits the drive control signal interrupts the current output from its own battery pack. In the optional power saving mode, if the output from at least one of the battery packs31a,31bis stopped, at least one of the fan3and the small electric apparatus8for general-purpose use is stopped from being energized (the mode control section29and the transformer circuit25interrupt the voltage output to at least one of the optional function connection terminal23and the general-purpose output socket24).

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

(1) At the series connection of the battery packs31a,31b,since the electric power tool or the like is stopped from the energization in the case where the protective circuit of at least one of the battery packs31a,31bis driven, it is possible to prevent the battery packs from being overloaded.

(2) At the parallel connection of the battery packs31a,31b,even in the case where the output from one of the battery packs31a,31bis restricted, the electric power tool is continuously energized by the other normal battery pack, so that it is possible to assure a long time period for energization.

(3) Since the cooling unit is connected to the optional function connection terminal23, separately from the electric power tool, it is possible to decrease the discomfort of the worker due to the heat generated from the battery packs31a,31b.

(4) Since the general-purpose output socket24which can energize the 12V-type vehicular equipment or the USB, which are available at a low price, is provided, the convenience is high and its general versatility as the power supply device is also high.

(5) Since the optional power saving mode is embedded in which when the protective circuit of either of the battery packs31a,31bis operated, at least one of the fan3and the small electric apparatus8for general-purpose use is stopped from the energization, it is possible to assure a long time period for energizing the main electric power tool. Meanwhile, the optional non-power saving mode can be selected in which the fan3and the small electric apparatus8for general-purpose use can be continuously energized until the output of both the battery packs31a,31bis stopped, so that it can be flexible in response to the needs of the worker.

(6) Since the worker is informed of state of the battery packs31a,31bby the informing unit27a,27b,such as LED, it is convenient that the worker can always figure out the state of the battery packs31a,31b.

It will be understood by those skilled in the art that the present invention has been described based on the embodiment, but various modifications for each constituent element or each process in the embodiment can be made without departing from the spirit or scope of the invention claimed in the claims. Modifications will now be described.

If the optional power saving mode of the embodiment is applied to a case in which there is one battery pack, it may be configured to maintain the energization to the electric power tool from the battery pack and to stop the energization to at least one of the fan3and the electric apparatus8for general-purpose use from the battery pack, when a ratio (residual capacity rate) of the output voltage to the rated voltage is lower than a predetermined value.

The informing units27a,27b,such as LED, may be provided to the shoulder belt6or the waist contact pad2, or the low-voltage tool-side adaptor85or the high-voltage tool-side adaptor95, instead of the housing11or in addition to the housing11. Alternatively, other informing units, such as alarm, may be employed or be used in combination with the informing units27a,27b.

The present invention provides illustrative, non-limiting aspects as follows:

(1) According to a first aspect, there is provided a power supply device including: a plurality of battery units each having a protective unit, an output voltage from the plurality of battery units being configured to energize an electric power tool; and a drive-limiting unit provided in a current path of the battery unit of each row, wherein each protective unit stops energization from the battery unit of its row by the drive-limiting unit provided in the current path of the battery unit of its row, when the battery unit of its row has an error.

(2) According to a second aspect, there is provided the power supply device according to the first aspect, wherein the plurality of battery units are connected in parallel with each other, and wherein, when the protective unit of the battery unit of one row emits a drive-limiting signal and the protective unit of the battery unit of another row does not emit a drive-limiting signal, energization from the battery unit of the one row is stopped and the electric power tool is energized from the battery unit of the other row.

(3) According to a third aspect, there is provided the power supply device according to the first aspect, wherein the plurality of battery units are connected in series to each other, and wherein the output of the voltage is stopped when the protective unit of at least one of the battery units emits a drive-limiting signal.

(4) According to a fourth aspect, there is provided the power supply device according to the first aspect, further including an adaptor provided between the plurality of battery units and the electric power tool, wherein the adaptor is configured to connect the plurality of battery units in parallel and includes the drive-limiting unit.

(5) According to a fifth aspect, there is provided the power supply device according to the first aspect, wherein series connection or parallel connection of the plurality of battery units is configured to be selected by a connection unit, and wherein, when the plurality of battery units are connected in series to each other, the energization to the electric power tool is stopped if the protective unit of at least one battery unit emits the drive-limiting signal.

(6) According to a sixth aspect, there is provided the power supply device according to the fourth aspect, wherein the power supply device is configured to energize the electric power tool and an electric apparatus other than the electric power tool, and wherein, when the plurality of battery units are connected in parallel with each other and the protective unit of the battery unit of at least one row emits the drive-limiting signal, the electric power tool is energized and the energization to the electric apparatus is stopped.

(7) According to a seventh aspect, there is provided the power supply device according to the fourth aspect, wherein the power supply device is configured to energize the electric power tool and an electric apparatus other than the electric power tool, and wherein, when the plurality of battery units are connected in parallel with each other and the protective unit of the battery unit of at least one row emits the drive-limiting signal, the electric power tool is energized, and the energization to the electric apparatus is stopped if a mode switching switch is in a first state but the electric apparatus is energized if the mode switching switch is in a second state.

(8) According to an eighth aspect, there is provided the power supply device according to the second aspect, further including a logical circuit configured to execute a predetermined logical operation on the drive-limiting signal from the protective unit of each battery unit.

(9) According to a ninth aspect, there is provided the power supply device according to the first aspect, further including an informing unit configured to inform presence or absence of the drive-limiting signal from the protective unit of each battery unit.

(10) According to a tenth aspect, there is provided the power supply device according to the ninth aspect, further including an adaptor configured to connect an electric apparatus with the power supply device.

(11) According to an eleventh aspect, there is provided the power supply device according to the first aspect, wherein the power supply device is a back pack type, and wherein the power supply device further comprises a cooling unit which is separate from the electric apparatus.

(12) According to a twelfth aspect, there is provided a power supply device including: a battery unit; and a terminal configured to energize the electric power tool and an electric apparatus having a lower output than that of the electric power tool by using an output voltage of the battery unit.

(13) According to a thirteenth aspect, there is provided the power supply device according to the twelfth aspect, wherein the power supply device is configured to maintain energization to the electric power tool from the battery pack and to stop energization to the electric apparatus from the battery pack, when a ratio of an actual output voltage to a rated voltage of the battery unit is lower than a predetermined value.

(14) According to a fourteenth aspect, there is provided A power supply device of a back pack type, the power supply device including: an output section configured to be connected to an electric power tool; and at least one of a ventilating unit configured to ventilate a periphery of the power supply device and a heating-cooling unit configured to heat or cool a periphery of the power supply device.

(15) According to a fifteenth aspect, there is provided the power supply device according to the fourteenth aspect, wherein the ventilating unit is configured to vent a back contact portion of the power supply device.

(16) According to a sixteenth aspect, there is provided the power supply device according to the fourteenth aspect, wherein the ventilating unit includes a fan.

(17) According to a seventeenth aspect, there is provided the power supply device according to the sixteenth aspect, wherein the fan is provided in a back contact pad portion of the power supply device.

(18) According to an eighteenth aspect, there is provided the power supply device according to the sixteenth aspect, wherein the fan is provided in a waist or shoulder harness.

(19) According to a nineteenth aspect, there is provided the power supply device according to the fourteenth aspect, wherein the heating-cooling unit includes an electrically-heated wire or a Peltier element.

(20) According to a twentieth aspect, there is provided the power supply device according to nineteenth aspect, wherein the electrically-heated wire or the Peltier element is provided in a back contact portion of the power supply device.

Note that all arbitrary combinations of the above-described constituents, and all conversions of expression, made among methods or systems, are also included in the present invention.