JP2005269747A - Electrical apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology of contributing to cope easily with the temperature elevating of a battery pack, on the body side of an electrical apparatus driven by using the battery pack. <P>SOLUTION: The electrical apparatus (circular saw 1 of desk-top type) includes an electrical apparatus body (circular saw body 300), a battery pack mounted in the electrical apparatus body to supply a load current (drive current) consumed by the electrical apparatus body, and a temperature index output means (thermistor TM, etc.) to detect the temperature of the battery pack 110 and to output a temperature index signal. The electrical apparatus body controls the amount of the load current supplied from the battery pack 110 to the electrical apparatus body, when the temperature of the battery pack 110 exceeds a first reference temperature T1(°C), based on the temperature index signal (the voltage value of both ends of the thermistor TM) from the temperature index output means. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a technique for dealing with high temperature of an assembled battery in the electrical apparatus body, with respect to the electrical apparatus having an electrical apparatus body and an assembled battery that supplies a load current consumed by the electrical apparatus body.

An electric tool comprising a rechargeable battery pack and a tool body, and a power tool provided with a mechanism for dissipating heat generated by discharge of the battery pack when the tool main body is driven using the battery pack, It is disclosed in JP-A-11-288744 (see Patent Document 1). In this electric power tool, air is taken in from the outside using a fan or the like to dissipate heat generated by the assembled battery.
Japanese Patent Laid-Open No. 11-288744

In such an electric tool, the influence on the heat generated by the assembled battery during use of the electric tool can be reduced, but if the heat dissipation function cannot keep up with the temperature rise of the assembled battery, There was a possibility that the battery life would be shortened by applying an excessive burden.
The present invention has been made in view of the above point, and provides a technology that contributes to easily dealing with the high temperature of an assembled battery in an electric device to which a load current is supplied using the assembled battery. Objective.

In order to achieve the above object, the invention described in each claim is configured.
(Invention of Claim 1)
According to invention of Claim 1, the electric equipment which has an electric equipment main body, an assembled battery, and a temperature parameter | index output means is comprised. The assembled battery is attached to the electric device body and supplies a load current consumed by the electric device body. The temperature index output means detects the temperature of the assembled battery and outputs a temperature index signal.
“Electrical equipment” widely includes battery-type power tools, battery-type lights, battery-type dust collectors, and the like that perform work by supplying load current from the assembled battery. Typically, when the “electric device” is a battery-powered power tool, the “electric device body” corresponds to the tool body that performs a predetermined processing operation on the workpiece, and the “electric device” is a battery-powered tool. In the case of a light, the “electric device body” corresponds to a structure that emits the light and the light. In the case where the “electric device” is a battery-type dust collector, the “electric device body” corresponds to a dust collector body that collects dust and the like.

  The “assembled battery” includes a wide range of battery packs that include one or a plurality of battery cells and supply a load current to an electric device. Typically, the assembled battery is configured using a secondary battery that can be repeatedly charged and used, such as a lithium ion battery, a nickel hydride battery, a nickel cadmium battery, or the like. Moreover, as an assembled battery, both the aspect comprised as a battery pack attached detachably with respect to an electric equipment main body, and the aspect incorporated in an electric equipment are included.

  For detecting the temperature of the assembled battery, a thermistor provided in the vicinity of the assembled battery is typically used. For example, when the thermistor is an NTC thermistor, the thermistor has a characteristic that the impedance value decreases as the temperature rises. That is, in the NTC thermistor, when the assembled battery is in a high temperature state, the impedance value is lower than that in the low temperature state, so that the voltage value detected at both ends is small. Using this characteristic, the temperature of the assembled battery can be calculated in the electric device.

The “temperature index signal” includes all signals that can calculate the temperature of the assembled battery as described above, signals that notify that the temperature of the assembled battery is at a predetermined value that exceeds a predetermined reference temperature, and the like.
In addition, the “temperature index output means” is provided on the assembled battery side to be attached to and detached from the electric device main body, and is provided on the electric device main body, and when the assembled battery is attached to the electric device main body, Any embodiment that is disposed at a location where the temperature of the battery can be detected is suitably included.
Note that the “temperature index output means” corresponds to an aspect in which a configuration for detecting the temperature of the assembled battery and a configuration for outputting a temperature index signal are combined. Typically, this corresponds to a circuit configuration required for detecting a voltage value at both ends of the thermistor, such as a thermistor and wiring connected to the thermistor.

  By the way, when supplying a load current to an electric equipment main body with an assembled battery, depending on the use condition of an electric equipment, when an assembled battery discharges, an appropriate heat | fever may generate | occur | produce. In particular, when the electrical equipment is a battery-type power tool that requires continuous high output in addition to instantaneous high output, the consumed load current is large, and depending on the usage conditions, considerable heat is generated in the assembled battery. This may cause various adverse effects on the assembled battery.

Therefore, the electrical device main body according to the present invention has a load current supplied from the assembled battery to the electrical device main body when the temperature of the assembled battery exceeds the first reference temperature based on the temperature index signal from the temperature index output means. Configured to control the amount.
Here, in order to perform the work of the electric device main body in the electric device main body, it is usually preferable to supply all the load current that can be supplied by the assembled battery to the electric device main body, and the first reference temperature or lower. Then, the amount of load current supplied from the assembled battery to the electric device main body is not controlled. That is, the condition that the control of the amount of load current is started when the temperature of the assembled battery exceeds the first reference temperature.
Here, the “first reference temperature” is lower by a predetermined value than the upper limit of the allowable allowable temperature range of the assembled battery. If the electric device body is used exceeding this temperature, an excessive burden is placed on the assembled battery. It is preferable that the temperature is appropriately set to a temperature that indicates a standard that will be lost. For example, when a nickel cadmium battery is used as a battery cell constituting the assembled battery, 80 degrees Celsius can be adopted as the first reference temperature.

  In addition, as the time when the control of the amount of the load current supplied from the assembled battery to the electric device main body is started and the time when the change of the amount of the load current actually supplied to the electric device main body starts, When the temperature of the assembled battery exceeds the first reference temperature, when the temperature of the assembled battery is likely to exceed the first reference temperature, at a predetermined time within a predetermined time when the temperature of the assembled battery exceeds the first reference temperature, etc. Either is acceptable.

  In addition, as a mode in which the amount of load current is controlled, a mode in which the supplied load current is reduced as the temperature of the assembled battery becomes higher, and the actual temperature of the assembled battery so that the temperature of the assembled battery becomes a predetermined temperature. And a mode in which the amount of load current is reduced by a predetermined value (a preset fixed value) when the temperature of the assembled battery exceeds the first reference temperature.

  Furthermore, the “amount of load current” supplied from the assembled battery to the electrical device main body is a mode in which the temperature of the assembled battery is continuously changed from the amount before the normal temperature exceeds the first reference temperature (in a normal state), step by step. It includes all aspects that are changed. Of these, the aspect that is changed stepwise may be changed in at least one step from the amount of the load current before the first reference temperature is exceeded, and suitably includes a case where it is changed in multiple steps.

  As described above, as a configuration for controlling the amount of the load current supplied to the electric device main body in various modes, the load is adjusted by adjusting the application time of the voltage applied to the electric device main body by the assembled battery. A configuration for reducing the current and other configurations for reducing the load current by adjusting the voltage value of the applied voltage are widely included. And, as a configuration for controlling the amount of load current by adjusting the application time of the applied voltage, a configuration for controlling connection or non-connection between the assembled battery and the electric device main body, particularly between the assembled battery and the electric device main body. A configuration in which connection / disconnection is repeated at a predetermined duty ratio (%) or a variable duty ratio (%) is preferably included.

  As described above, when the temperature index signal output from the temperature index output means is a signal capable of calculating the temperature of the assembled battery, typically, in the electric device main body, first, based on the temperature index signal. Then, the temperature of the assembled battery is calculated, and it is determined whether or not the calculated temperature of the assembled battery exceeds the first reference temperature. When it is determined that the first reference temperature is exceeded, the amount of load current supplied to the electric device main body is controlled. On the other hand, when the temperature index signal is a signal notifying that the temperature of the assembled battery has exceeded the first reference temperature, the electric device body receives a load current supplied to the electric device body when receiving the temperature index signal. The amount of control.

According to the electric device of the present invention, when the temperature of the assembled battery is equal to or lower than the first reference temperature, all the load currents that can be supplied from the assembled battery to the electric device body are supplied, and the temperature of the assembled battery When the temperature exceeds the first reference temperature, the amount of load current supplied from the assembled battery to the electrical device body can be controlled by the electrical device body. Typically, as the first reference temperature, a temperature is set that indicates a reference that would put an excessive burden on the assembled battery if the electric device body is used beyond this temperature. Can reduce the amount of load current supplied to the electric device body as compared with the case where the temperature is lower than this temperature. Thereby, the possibility that an excessive load is applied to the assembled battery is reduced, and the life of the assembled battery can be prolonged.
In many cases, the operator can recognize that control of the amount of load current supplied to the electric device body has started. For example, if the amount of load current supplied is reduced, if the electrical device is a battery-powered tool, the motor rotation speed is limited and the output is reduced, and the electrical device is a battery-powered rechargeable light. The brightness of the light goes down. The operator recognizes that the assembled battery has been heated to a higher temperature (or is being heated to a higher temperature) than the normal temperature state, or the remaining electricity amount of the assembled battery has decreased, and determines whether or not depending on the situation. can do. And when an operator judges that the assembled battery is high temperature, it can devise to use continuously, taking measures, such as using intermittently with a light load. Also, in the electrical equipment, if the amount of load current supplied to the electrical equipment body is reduced, it is limited to use at a lighter load than usual, so it is easy for the operator to take the above measures. It became. It should be noted that when control of the amount of load current supplied to the electric device main body is started, an operator can more easily recognize this situation if a configuration in which an alarm function such as an alarm is activated is provided.
In particular, electric devices such as battery-type power tools that require continuous high output in addition to instantaneous high output (especially, screw tightening for so-called heavy loads with a drive current (load current) of 20 A or more) In the case of a tool, a cutting tool, etc.), since the drive current (load current) supplied from the assembled battery to the drive motor of the electric tool is large, considerable heat may be generated when the assembled battery is discharged. Therefore, the present invention can be particularly suitably applied to such a power tool.

(Invention of Claim 2)
According to the invention described in claim 2, when the temperature of the assembled battery exceeds the first reference temperature, the electrical device main body of the electrical apparatus according to claim 1 is configured to correspond to the temperature of the assembled battery. The amount of load current supplied from the battery to the electric device main body is continuously changed.
Typically, when the temperature of the assembled battery exceeds the first reference temperature, the electric device main body continuously decreases the amount of load current supplied as the temperature of the assembled battery increases.
In addition, “continuous” means that the change in the load current as a result of control is continuous. Therefore, when the amount of load current is changed by changing the duty ratio (%) of the voltage applied to the electric device body in accordance with the temperature of the assembled battery, typically the change in the duty ratio (%) The load current can be continuously changed by reducing the amount (for example, precisely controlling the battery pack in response to a small temperature change of the assembled battery).
According to the electric device of the present invention, even when the assembled battery is in a high temperature state, the ability of the assembled battery can be utilized to the maximum according to the situation.

(Invention of Claim 3)
According to the third aspect of the present invention, a plurality of reference temperatures higher than the first reference temperature are set in the electric device main body of the electric device according to the first aspect. Then, when the temperature of the assembled battery exceeds the first reference temperature, the electrical equipment body sequentially decreases the amount of load current supplied from the assembled battery to the electrical equipment body every time the plurality of reference temperatures are exceeded. It is configured as follows.
The set number of “plurality of reference temperatures” may be set according to the specifications of the electrical equipment, and the amount of change in the load current that changes sequentially each time the plurality of reference temperatures is sequentially exceeded changes. For example, the smaller the set number of reference temperatures, the greater the amount of change when the load current changes, resulting in a stepwise change.
Further, typically, data on the duty ratio (%) of the voltage applied to the electric device main body corresponding to a plurality of reference temperatures is stored in the electric device main body. Here, the higher the reference temperature, the smaller the corresponding duty ratio is set and stored. The electrical device main body only needs to extract and set a duty ratio (%) corresponding to the temperature stored in advance each time a plurality of reference temperatures are sequentially exceeded.
According to the electric device of the present invention, when the temperature of the assembled battery exceeds the first reference temperature, it becomes easy to control the amount of load current supplied from the assembled battery to the electric device main body in the electric device main body.

(Invention of Claim 4)
According to the invention described in claim 4, in the electric device according to any one of claims 1 to 3, the electric device main body exceeds the second reference temperature in which the temperature of the assembled battery is higher than the first reference temperature. When in a high temperature state, the supply of load current from the assembled battery is cut off.
The “second reference temperature” is an upper limit value of the allowable allowable range of the assembled battery, and a temperature that indicates a reference that should not be used with an electric device exceeding this temperature is appropriately set. Is preferred. For example, when a nickel cadmium battery is used as the battery cell constituting the assembled battery, 100 degrees Celsius can be adopted as the second reference temperature.
According to the electrical device of the present invention, when the temperature of the assembled battery reaches a high temperature state exceeding the second reference temperature, the supply of load current from the assembled battery to the electrical device main body is interrupted, so that the assembled battery is further heated. By preventing the battery from entering the state, the possibility of deterioration of the assembled battery due to high temperature can be reduced.

  According to the present invention, there is provided a technique that contributes to easily dealing with the high temperature of an assembled battery by using the assembled battery and the electric device main body.

(First embodiment)
Hereinafter, an example of the best mode for carrying out the present invention will be described with reference to FIGS. In the present embodiment, as an example, a case will be described in which a table-type circular saw 1 is used as an electric device that is used by mounting a battery pack having a rechargeable assembled battery on the main body of the electric device. The configuration of the circular saw 1 in which the battery pack 100 is mounted on the circular saw body 300 according to the present embodiment is schematically shown in FIG. The electrical configuration of the circular saw body 300 and the battery pack 100 is schematically shown in the block diagram of FIG. In addition, FIG. 3 schematically shows a configuration when the battery pack 100 is connected to the charger 200 in a block diagram. FIG. 4 is a flowchart showing an operation of controlling the amount of drive current supplied from the battery pack 100 to the circular saw body 300 by the circular saw body 300. 5 and 6 show the temperature of the assembled battery included in the battery pack 100 and the state of the drive current supplied from the assembled battery to the circular saw body 300 over time.
The circular saw 1 of the present embodiment corresponds to the “electric equipment” of the present invention, the circular saw main body 300 corresponds to the “electric equipment main body” of the present invention, and the drive current supplied to the circular saw main body 300 is This corresponds to the “load current” of the present invention.

First, with reference to FIGS. 1 and 2, the circular saw body 300 of the circular saw 1 of the present invention, and the configuration of the battery pack 100 that is mounted on the circular saw body 300 and supplies a drive current to the circular saw body 300. explain. Furthermore, the outline of the structure by which the battery pack 100 is charged with the conventional charger 200 is demonstrated using FIG.
As shown in FIGS. 1 and 2, the circular saw 1 includes a circular saw body 300 and a battery pack 100. The circular saw body 300 includes a motor 310 that operates the circular saw body 300, a controller 320 that controls the motor 310, a drive switch 330 of the circular saw 1 that is turned on / off by an operator operating the trigger 350, It has a switching element 340 (switching circuit) that is on / off controlled by the control unit 320, terminals TS1 to TS3 connected to corresponding terminals of the battery pack 100, and the like.
Then, as shown in FIG. 1, the battery pack 100 is attached to the circular saw body 300, whereby the corresponding terminals of the circular saw body 300 and the battery pack 100 are connected, and the assembled battery 110 of the battery pack 100 is connected. The drive current can be supplied to the circular saw body 300.

As shown in FIG. 2, the terminal TS1 of the circular saw body 300 is one end of the drive switch 330 (the left terminal shown in FIG. 2), and the other end of the drive switch 330 (the right terminal shown in FIG. 2) is the input of the motor 310. It is connected to one end of the terminal (the upper terminal shown in FIG. 2). Also, the terminal TS2 is connected to the emitter of the switching element 340, the collector of the switching element 340 is connected to the other end of the input terminal of the motor 310 (the lower terminal shown in FIG. 2), and the base of the switching element 340 is connected to the control unit 320. Yes.
Accordingly, when a battery pack 100 described later is mounted on the circular saw body 300, the plus side of the assembled battery 110 provided in the battery pack 100 is connected to the terminal TS1 via the terminal TE1, and the minus side of the assembled battery 110 is connected to the terminal TE2. When the switching element 340 and the drive switch 330 are on, the drive current is supplied from the assembled battery 110 of the battery pack 100 to the motor 310 so that the motor 310 can be driven.
The mode in which the switching element 340 is on / off controlled by the control unit 320 will be described in detail later.

When the battery pack 100 is mounted on the circular saw main body 300, the control unit 320 is configured to operate with a control power source of approximately 5V, which is not shown in the figure, divided from the voltage of the assembled battery 110. . The control unit 320 is provided with a storage unit that stores a program for controlling the operation of the circular saw body 300 such as drive control of the motor 310 (on / off control of the switching element 340, etc.), various setting values, and the like. Yes. The control unit 320 appropriately reads out and executes the control program and various setting values.
In addition, the control unit 320 is connected to the terminal TS3. When the battery pack 100 is mounted on the circular saw body 300, the terminal TS3 is connected to a terminal TE3 of the battery pack 100 described later. Thus, the control unit 320 is connected to one end of the thermistor TM of the battery pack 100 via the terminal TE3 and the terminal TS3. The control unit 320 is provided with a temperature detection unit 321 and can detect the voltage value (temperature index signal) at both ends of the detected thermistor TM.

Next, the outline of the configuration of the battery pack 100 that supplies the drive current to the circular saw body 300 will be described with reference to FIG.
The battery pack 100 includes an assembled battery 110 in which nickel cadmium battery cells are connected in series, a thermistor TM disposed in the vicinity of the assembled battery 110, and terminals connected to corresponding terminals of the charger 200 and the circular saw body 300. TE1 to TE3 are provided.

The plus side (upper side shown in FIG. 2) of the assembled battery 110 is connected to the terminal TE1 of the battery pack 100, and the minus side (lower side shown in FIG. 2) of the assembled battery 110 is connected to the terminal TE2 of the battery pack 100. . Thereby, when the battery pack 100 is mounted on the circular saw body 300, the terminals TE1 and TE2 are connected to the terminals TS1 and TS2 of the circular saw body 300, respectively, and a drive current can be supplied to the circular saw body 300. It becomes. When the battery pack 200 is attached to a charger 200 described later (refer to FIG. 3 together), the terminals TE1 and TE2 are connected to the terminals TE11 and TE12 of the charger 200, respectively, and the assembled battery 110 is charged.
Further, the minus side of the assembled battery 110 is connected to one end of the thermistor TM, and the other end of the thermistor TM is connected to the terminal TE3. The thermistor TM is disposed in the vicinity of the assembled battery 110. When the thermistor TM is an NTC thermistor, the temperature value of the assembled battery 110 decreases, and the impedance value of the thermistor TM decreases and the voltage value at both ends decreases. have. Using this characteristic, the circular saw body 300 of the present embodiment is configured to detect the temperature of the assembled battery 110.
The assembled battery 110 of the present embodiment corresponds to the “assembled battery” in the present invention, and the circuit configuration for detecting the voltage value (temperature index signal) at both ends of the thermistor TM and the thermistor TM is the “temperature index output means” in the present invention. Corresponding to

Next, the outline of the configuration of the charger 200 that charges the battery pack 100 will be described with reference to FIG.
The charger 200 includes a power supply circuit 210 that converts AC input power to a DC power supply for charging the battery pack 100, a charge control unit 220 that controls the power supply circuit 210, terminals TE11 to TE13 for connection to the battery pack 100, AC Input terminals SE11 and SE12 for connecting an input power supply are provided.

The input side of the power supply circuit 210 is connected to input terminals SE11 and SE12 to which an AC input power supply can be connected. The power supply output terminal of the power supply circuit 210 is connected to the output terminal TE11 of a DC power supply that is converted from the AC input power supply by the power supply circuit 210 and charges the battery pack 100 under the control of the charging control unit 220. The ground terminal of the power supply circuit 210 is connected to the output terminal TE12 via a shunt resistor. Thereby, in the charger 200 shown in FIG. 3, the output terminal TE11 is a power supply terminal, and the output terminal TE12 is a ground potential supply terminal.
Although not particularly shown, the power supply circuit 210 outputs a control power supply (generally 5 V) converted from an AC input power supply and supplied to an IC or the like in the charger 200, and the charge control unit 220 or the like. Has been supplied to.
In addition, the terminal TE12 and one end of the shunt resistor are connected to the charging control unit 220, whereby the charging control unit 220 can detect the charging current value and control the charging current. Further, the terminal TE11 is connected to the charge control unit 220, and thus the charge control unit 220 is configured to be able to detect the voltage value at both ends of the assembled battery 110 of the battery pack 100.
In addition, the charging control unit 220 is connected to the terminal TE13, so that the charging control unit 220 can detect the voltage value at both ends of the thermistor TM of the battery pack 100.

Next, the outline of the operation of charging the battery pack 100 (that is, the assembled battery 110) with the charger 200 will be described with reference to FIG.
First, an AC input power source is connected to the input terminals SE11 and SE12 of the charger 200. As a result, the control power source converted from the AC input power source by the power source circuit 210 is supplied to the charge control unit 220 in the charger 200, whereby the charger 200 starts operating.
When the battery pack 100 is attached to the charger 200, the terminals TE11 to TE13 of the charger 200 are connected to the terminals TE1 to TE3 of the battery pack 100, respectively.
With this connection, the charging control unit 220 of the charger 200 causes the power supply circuit 210 to supply a charging current to the battery pack 100 and charging of the assembled battery 110 of the battery pack 100 is started.

  Generally, the charger has a function of detecting charging of the assembled battery being charged by various methods and stopping charging. The nickel cadmium battery cell constituting the assembled battery 110 of the battery pack 100 of the present embodiment has a characteristic that the voltage value per cell is reduced by about 5 to 20 mA from the peak value at the end of charging. Therefore, in charger 200, charging control unit 220 detects this voltage drop and stops charging (generally referred to as a -ΔV method). The charger 200 stops charging when it is determined that the assembled battery 110 is in a high temperature state based on the voltage values at both ends of the thermistor TM in the battery pack 100 during charging.

The battery pack 100 prepared by charging in this way is mounted on the circular saw body 300 as shown in FIG. 2, and the circular saw body 300 is driven.
In the present embodiment, when the circular saw body 300 detects that the assembled battery 110 of the battery pack 100 exceeds the first reference temperature T1 (° C.), the circular saw body 300 sets the switching element 340 to a predetermined “duty ratio” (% ) To control the drive current by on / off control. However, if it is still detected that the temperature of the assembled battery 110 has risen to exceed the second reference temperature Tc (° C.), the supply of the drive current is cut off. This series of operations will be described with reference to a flowchart of a control program executed by the control unit 320 of the circular saw body 300 shown in FIG.
At this time, the first reference temperature T1 is set to a temperature that indicates a reference that would put an excessive burden on the assembled battery 110 when the circular saw body 300 is used beyond this temperature. Further, the second reference temperature T2 is set to a temperature that indicates a reference that should not exceed the temperature and use the assembled battery 110 using the circular saw body 300.

  The “duty ratio” (%) is the ratio (%) of the time (seconds) that the switching element 340 is in the ON state in the period (seconds) when the switching element 340 is in the ON state, and the switching element 340 is in the ON state. The driving current can be supplied from the assembled battery 110 to the motor 310 of the circular saw body 300 at a certain time, and the supply of the driving current to the motor 310 is cut off at the time when the switching element 340 is in the off state (in addition, (See FIG. 2). In other words, when the set duty ratio (%) is small, the amount of drive current supplied to the motor 310 is smaller than when the set duty ratio (%) is large. Therefore, when the temperature of the assembled battery 110 is high, it is preferable to set the duty ratio (%) small. In the present embodiment, when it is detected that the temperature T (° C.) of the assembled battery 110 exceeds the first reference temperature T1 (° C.), the switching element 340 is controlled to be turned on / off at a preset duty ratio of 50%. The case where it does is demonstrated.

When the processing of the control program shown in FIG. 4 is started, first, in step S10, the control unit 320 determines whether or not the operation switch 330 is in an on state. If the operation switch 330 is in the on state (Yes in step S10), the process proceeds to step S12. If the operation switch 330 is not in the on state (No in step S10), the process waits until the operation switch 330 is in the on state.
In step S12, the control unit 320 controls to turn on the switching element 340 to drive the motor 310 (no duty ratio control, normal mode), and proceeds to the process of step S14.
In step S14, the controller 320 determines whether or not the temperature T (° C.) of the assembled battery 110 exceeds the first reference temperature T1 (° C.). If it exceeds 1st reference temperature T1 (degreeC), it will progress to the process of step S16, and if it is below 1st reference temperature T1 (degreeC), the drive of the motor 310 will be continued as it is.
In step S16, the control unit 320 performs on / off control of the switching element 340 with a duty ratio of 50%, drives the motor 310 with duty ratio control, and proceeds to the process of step S18.
In step S18, the control unit 320 determines whether or not the temperature T (° C.) of the assembled battery 110 exceeds the second reference temperature Tc (° C.). If the temperature exceeds the second reference temperature Tc (° C.), the process proceeds to step S20. If the temperature is equal to or lower than the second reference temperature Tc (° C.), the motor 310 continues to be driven with the duty ratio control.
In step S20, control unit 320 stops motor 310 and ends.
In addition, the process which discriminate | determines the temperature of the assembled battery 110 of these steps S14 and S18 respond | corresponds to the temperature detection part 321 shown in FIG.

The timing charts of FIGS. 5 and 6 show the on / off state of the switching element 340 thus controlled on / off, the temperature transition of the assembled battery 110, and the transition of the drive current supplied to the motor 310. FIG.
First, in the case shown in FIG. 5, until the time s1, the drive current is continuously supplied from the assembled battery 110 to the motor 310 as usual. (It is determined in step S14 in FIG. 4 that the temperature T (° C.) of the assembled battery 110 does not exceed the first reference temperature T1 (° C.).)
At time s1, it is detected that the temperature of the assembled battery 110 exceeds the first reference temperature T1 (° C.) (in the process of step S14 in FIG. 4, the temperature of the assembled battery 110 is changed to the first reference temperature T1 ( Is determined), and on / off control of the switching element 340 at a predetermined cycle and a duty ratio of 50% is started (processing of step S16 shown in FIG. 4). As a result, the drive current supplied to the motor 310 is reduced to 50% of the normal state.
At time s2, it is detected that the temperature of the assembled battery 110 exceeds the second reference temperature Tc (° C.) (the temperature T (° C.) of the assembled battery 110 is the second temperature in the process of step S18 of FIG. It is determined that the temperature exceeds the reference temperature Tc (° C.)), and it is determined that the switching element 340 is controlled to be turned off (step S20 shown in FIG. 4). Thereby, the motor 310 is stopped.

  In the case shown in FIG. 6, it is detected that the temperature of the assembled battery 110 exceeds the first reference temperature T1 (° C.) at time s1, and the switching element 340 has a predetermined cycle and a duty ratio of 50%. When the on / off control is started and the drive current supplied to the motor 310 is reduced to 50% of the normal state, the temperature rise of the assembled battery 110 is reduced. In this state, the user of the circular saw 1 can continue the use if the load is lightened even if the temperature of the assembled battery 110 exceeds the first reference temperature T1 (° C.).

Thus, in the circular saw body 300 of the circular saw 1 of the present embodiment, when the temperature T (° C.) of the assembled battery 110 of the battery pack 100 is equal to or lower than the first reference temperature T1 (° C.), the assembled battery 110 Is supplied to the circular saw body 300, and when the first reference temperature T1 (° C.) is exceeded, the drive current of the motor 310 supplied from the assembled battery 110 to the circular saw body 300 is supplied. Thus, it is possible to continue the operation while reducing the burden on the assembled battery 110 and the circular saw body 300. In addition, when the temperature T (° C.) of the assembled battery 110 exceeds the first reference temperature T1 (° C.), the user reduces the output of the motor 310 by reducing the amount of drive current supplied to the motor 310. Therefore, it is recognized that the battery pack 110 is getting hot, and it is easy to take measures for continuous use while taking measures such as intermittent use with a light load.
Furthermore, when the temperature of the assembled battery 110 continues to rise and exceeds the second reference temperature Tc (° C.), the supply of drive current from the assembled battery 110 to the motor 310 of the circular saw body 300 may be cut off. it can. Therefore, as shown in FIG. 5, when the temperature of the assembled battery 110 exceeds the second reference temperature Tc (° C.), the motor 310 is automatically stopped. There is also a sense of security when the circular saw 1 is used continuously under load.
In addition, since the possibility that the temperature of the assembled battery 110 exceeds the second reference temperature Tc (° C.) during use is reduced, the life of the assembled battery 110 and the circular saw body 300 can be extended.
Furthermore, according to the circular saw 1, the temperature of the assembled battery 110 is monitored by the circular saw body 300 using the existing thermistor TM of the battery pack 100 without any special design change on the battery pack 100 side. be able to. That is, the amount of drive current of the motor 310 supplied from the assembled battery 110 to the circular saw body 300 can be controlled by the temperature of the assembled battery 110 with a simple and inexpensive configuration.

  In this embodiment, for convenience of explanation, the assembled battery 110 is continuously discharged in FIGS. 5 and 6 to drive the circular saw 1 continuously, and the assembled battery 110 is processed in one processing operation. In the description, the temperature T exceeds the first reference temperature T1 (° C.) and exceeds the second reference temperature Tc (° C.) from the normal state. However, in reality, the temperature T of the assembled battery 110 is rarely increased in such a single processing operation, and the temperature T of the assembled battery 110 is intermittent after a large number of processing operations. When the temperature rises, the state becomes similar to the state shown in FIGS.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIGS. In the first embodiment, the case where the cycle (seconds) and the duty ratio (%) for controlling on / off of the switching element 340 are fixed (50%) has been described, but in this embodiment, at that time A case where the above-described duty ratio (%) is determined based on the temperature T (° C.) of the assembled battery 110 will be described. That is, the control program executed by the control unit 320 is different from the first embodiment. Since other configurations are the same as those of the first embodiment (refer to FIGS. 1 and 2 together), description thereof is omitted. FIG. 7 shows a map used when the control unit 320 determines the duty ratio (%) based on the temperature T (° C.) of the assembled battery 110. FIG. 8 shows the temperature T (° C.) of the assembled battery 110 included in the battery pack 100 and the state of the drive current supplied from the assembled battery 110 to the circular saw body 300 over time.

In the present embodiment, the control unit 320 detects the temperature T (° C.) of the assembled battery 110 when the processing of the control program is started and the operation switch 330 is on, and based on the map shown in FIG. A duty ratio (%) corresponding to the detected temperature T (° C.) is extracted. As a result, the switching element 340 is on / off controlled, and the motor 310 is driven by duty ratio control.
If the temperature T (° C.) of the assembled battery 110 is equal to or lower than the first reference temperature T1 (° C.), the motor 310 is driven normally (no duty ratio control).
If the temperature T (° C.) of the assembled battery 110 exceeds the first reference temperature T1 (° C.) and is equal to or lower than the set temperature T2 (° C.), the motor 310 is connected to a duty ratio D1 (less than 100% duty ratio). %) Duty ratio control.
If the temperature T (° C.) of the assembled battery 110 exceeds the set temperature T 2 (° C.) and is equal to or lower than the set temperature T 3 (° C.), the motor 310 is driven with a duty ratio D 2 (%) smaller than the duty ratio D 1 (%). It is driven by the duty ratio control.
If the temperature T (° C.) of the assembled battery 110 exceeds the set temperature T 3 (° C.) and is equal to or lower than the set temperature T 4 (° C.), the motor 310 is driven with a duty ratio D 3 (%) smaller than the duty ratio D 2 (%). It is driven by the duty ratio control.
If the temperature T (° C.) of the assembled battery 110 exceeds the set temperature T 4 (° C.) and is equal to or lower than the second reference temperature Tc (° C.), the motor 310 is driven with a duty ratio D 4 (less than the duty ratio D 3 (%). %) Duty ratio control.
If the temperature T (° C.) of the assembled battery 110 exceeds the second reference temperature Tc (° C.), the driving of the motor 310 is stopped.

The timing chart of FIG. 8 shows changes in the on / off state of the switching element 340 thus controlled on / off, the temperature of the assembled battery 110, and the drive current supplied to the motor 310.
First, in the case shown in FIG. 8, the driving current is continuously supplied from the assembled battery 110 to the motor 310 until time s1. At time s1, it is detected that the temperature T (° C.) of the assembled battery 110 has exceeded the first reference temperature T1 (° C.), and the switching element 340 is turned on / off at a predetermined cycle and duty ratio D1 (%). When the off-control is started, and at time s2, it is detected that the temperature T (° C.) of the assembled battery 110 has exceeded the set temperature T2 (° C.), and the predetermined period and duty ratio D2 (%) of the switching element 340 are detected. The on / off control at is started. At time s3, it is detected that the temperature T (° C.) of the assembled battery 110 has exceeded the set temperature T3 (° C.), and the on / off control is performed at a predetermined cycle and duty ratio D3 (%) of the switching element 340. Is started. At time s4, it is detected that the temperature T (° C.) of the assembled battery 110 has exceeded the set temperature T4 (° C.), and the on / off control is performed at a predetermined cycle and duty ratio D4 (%) of the switching element 340. Is started. At time s5, it is detected that the temperature T (° C.) of the assembled battery 110 has exceeded the second reference temperature Tc (° C.), and the switching element 340 is controlled to be turned off.

  In the circular saw body 300 of the circular saw 1 of the present embodiment, the duty ratio (%) corresponding to the temperature T (° C.) of the assembled battery 110 of the battery pack 100 at that time can be determined. Therefore, since the possibility that the temperature of the assembled battery 110 exceeds the second reference temperature Tc (° C.) during use is further reduced, the life of the assembled battery 110 and the circular saw body 300 can be extended.

In the present embodiment, the assembled battery 110 is continuously discharged in FIG. 8 to continuously drive the circular saw 1, and the temperature T of the assembled battery 110 is changed from the normal state to the first state in one processing operation. The case where the temperature exceeds one reference temperature T1 (° C.), exceeds the set temperatures T1 to T4 (° C.) and the second reference temperature Tc (° C.) has been described as an example. However, in an actual machining operation, the temperature T of the assembled battery 110 is rarely increased in this manner, and the temperature T of the assembled battery 110 is intermittently increased through a number of machining operations. The state is similar to the state shown in FIG.
“Set temperatures T1 to T4” in the present embodiment correspond to “a plurality of reference temperatures higher than the first reference temperature” in the present invention.

In the embodiment, the case where the assembled battery 110 is accommodated in the battery pack 100 and can be attached to the circular saw body 300 has been described. However, the assembled battery 110 is accommodated in the circular saw body 300 together with the temperature index output means. May be. According to this, the circular saw 1 can be reduced in size.
Moreover, the assembled battery 110 may be accommodated in the battery pack 100, and the temperature index output unit may be accommodated in the circular saw body 300. Thereby, the circuit which outputs a temperature index signal is not divided by the attachment and detachment of the battery pack 100 including the assembled battery 110, and the reliability of the temperature index signal is improved.

  In the embodiment, the voltage value at both ends of the thermistor TM is used as the temperature index signal, thereby calculating the temperature of the assembled battery 110, and whether the temperature of the assembled battery 110 is in a high temperature state exceeding a predetermined reference temperature. However, the temperature index output means detects that the assembled battery 110 is in a high temperature state, and, for example, a signal indicating that the assembled battery 110 is equal to or higher than the first reference temperature T1 (° C.). It may be configured to output as a signal. According to this, when the temperature index signal is detected in the circular saw body 300, the switching element 340 may be controlled to be turned on / off, and the control becomes easy.

The present invention can also be applied to battery-type lights, battery-type dust collectors, and the like. For example, when applied to a battery-type light, the brightness of the light is adjusted to be small when the load current is controlled and reduced. Further, when applied to a battery-type dust collector, the suction capacity of the dust collector is adjusted to be small when the load current is controlled and reduced.
Further, in the embodiment, whether or not to control the amount of load current is determined based on the temperature T of the assembled battery, but may be configured to be determined based on the degree of increase in temperature T (ΔT). These may be used in combination. Of course, ΔT may also be used when determining the duty ratio (%) of the switching element 340. If the temperatures T and ΔT are used in combination, more precise control can be performed.
Alternatively, the supply of the load current may be cut off by predicting that the temperature of the assembled battery 110 will soon reach the second reference temperature Tc based on ΔT or the like.

The circular saw body 300 is provided with an alarm LED (not shown), and the LED blinks when the temperature T (° C.) of the assembled battery 110 exceeds the first reference temperature T1 (° C.). When the temperature T (° C.) of the assembled battery 110 exceeds the second reference temperature Tc (° C.), the LED may be turned on.
The circular saw body 300 is provided with a sound source capable of outputting an alarm sound and a speaker (not shown), and the temperature T (° C.) of the assembled battery 110 is set to the first reference temperature T 1 (° C.). If it exceeds, an intermittent alarm sound may be output, and if the temperature T (° C.) of the assembled battery 110 exceeds the second reference temperature Tc (° C.), a continuous alarm sound may be output.
Thus, if the circular saw main body 300 is configured to output an alarm, it is easy for an operator to recognize that the assembled battery 110 is at a high temperature.

In view of the gist of the present invention, the following aspects can be configured.
(Aspect 1)
"Electric device according to any one of claims 1 to 4,
The electric device body includes a switching circuit provided in a path through which a load current is supplied from the assembled battery,
An electric device configured to control the amount of load current supplied from the assembled battery to the electric device main body by performing on / off control of the switching circuit. "
The “switching circuit” broadly includes electrical switching means such as a switching element that is turned on / off by the main body of the electrical equipment.
The “path” through which the load current is supplied typically represents a drive circuit (load current) supply circuit for the motor when a motor is provided in the electric device body.
According to the electrical device of this aspect, the configuration for controlling the amount of load current supplied from the assembled battery to the electrical device body in the electrical device body can be realized with a simple and inexpensive configuration.

(Aspect 2)
"Electric device according to any one of claims 1 to 4 and aspect 1,
A battery pack that can be attached to the electric device main body and that houses the assembled battery and the temperature index output means,
The battery pack is configured to be connected to the electric device main body by being attached to the electric device main body, to supply a load current to the electric device main body, and to output the temperature index signal. "
Typically, the battery pack and the electric device main body are each provided with terminals that are connected to each other by being mounted.
According to the electric device of this aspect, the assembled battery and the temperature index output means accommodated in the battery pack can be easily attached to and detached from the electric device main body. Thus, when the assembled battery becomes unusable due to its life or the like, the battery pack has only to be replaced, and the maintainability is excellent. Further, when charging the assembled battery, the battery pack may be removed from the electric device main body and connected to a corresponding charger, which improves convenience. In addition, by accommodating the temperature index output means in the battery pack together with the assembled battery, a more accurate index related to temperature can be detected.

The external view which attached the battery pack 100 to the circular saw main-body part 300 which concerns on a 1st form is shown. A block diagram of the circular saw body 300 according to the first embodiment is shown together with a block diagram of the battery pack 100 that supplies a drive current to the circular saw body 300. The block diagram of the battery pack 100 is shown together with the block diagram of the charger 200 that charges the battery pack 100. The flowchart figure of the control program which the control part 320 of the circular saw main-body part 300 which concerns on 1st Embodiment performs. 4 is a timing chart showing a change in temperature T of the assembled battery 110, an on / off state of the switching element 340, and an amount of drive current supplied to the motor 310. FIG. 4 is a timing chart showing a change in temperature T of the assembled battery 110, an on / off state of the switching element 340, and an amount of drive current supplied to the motor 310. FIG. The map of the duty ratio (%) corresponding to the temperature T of the assembled battery 110 which the control part 320 of the circular saw main-body part 300 which concerns on 2nd Embodiment uses is shown. In 2nd Embodiment, the timing chart figure which shows the change of the temperature of the assembled battery 110, the ON / OFF state of the switching element 340, and the quantity of the drive current supplied to the motor 310 is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Circular saw 100 Battery pack 110 Battery pack 200 Battery charger 300 Circular saw main-body part 310 Motor 320 Control part 330 Operation switch 340 Switching element TM Thermistor

Claims (4)

An electric device main body, an assembled battery that is attached to the electric device main body and supplies a load current consumed by the electric device main body, and a temperature index output means that detects a temperature of the assembled battery and outputs a temperature index signal When the temperature of the assembled battery exceeds a first reference temperature based on the temperature index signal from the temperature index output means, the electrical apparatus main body has the electrical apparatus main body from the assembled battery to the electrical apparatus body. An electrical device configured to control the amount of load current supplied. The electric device according to claim 1,
When the temperature of the assembled battery exceeds a first reference temperature, the electrical equipment body continuously corresponds to the temperature of the assembled battery and the amount of load current supplied from the assembled battery to the electrical equipment body is continuous. Electrical equipment that is configured to change in a moving manner. The electric device according to claim 1,
A plurality of reference temperatures higher than the first reference temperature are set in the electric device body,
When the temperature of the assembled battery exceeds the first reference temperature, the electrical equipment body determines the amount of load current supplied from the assembled battery to the electrical equipment body each time the plurality of reference temperatures are sequentially exceeded. Electrical equipment that is configured to decrease sequentially. The electric device according to any one of claims 1 to 3,
When the temperature of the assembled battery exceeds a second reference temperature that is higher than the first reference temperature, the electrical apparatus body cuts off the supply of load current from the assembled battery to the electrical device body. Electrical equipment that is configured as follows.

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