JP2012213690A - Atomizer and electric tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric tool capable of selectively connecting to multiple kinds of battery packs with different battery voltages and to provide an atomizer.SOLUTION: The atomizer 100 includes: conversion means 10 and 13 for converting a battery voltage of a battery pack 6 to output a desired electric power; a battery voltage detection means 12 for detecting a battery voltage; and a motor 1a which is driven by the electric power output from the conversion means. In the conversion means, multiple kinds of battery packs 6 with different battery voltages can be selectively electrically connected.

Description

  The present invention relates to an electric power tool that operates by supplying power from a battery pack, and more particularly to an atomizer.

  Among the atomizers, there is a type that operates by supplying power from a battery pack.

JP 2001-001179 A

  However, only a specific type of battery pack that outputs a constant voltage can be used as a battery pack that can supply power to the sprayer.

  In view of such a situation, the present invention intends to provide a highly versatile power tool and a sprayer.

  The sprayer of the present invention is driven by conversion means for converting the battery voltage of the battery pack and outputting power of a desired voltage, battery voltage detection means for detecting the battery voltage, and electric power output from the conversion means. And a plurality of types of battery packs having different battery voltages can be selectively electrically connected to the conversion means.

  Preferably, the conversion means outputs a constant voltage of power regardless of the battery voltage.

  Preferably, the conversion means steps down and outputs the battery voltage.

  Preferably, the battery pack further includes a main body on which the battery pack is detachably mounted. The main body includes a lid that covers the battery pack, and the lid is fixed to the main body in a state of covering the battery pack. It further has a fixing mechanism.

  According to the above configuration, when the battery pack is connected and becomes operable by a user operation, the battery voltage detection unit detects the battery voltage of the battery pack, and the conversion unit converts the output voltage from the battery pack. Output a constant voltage of power. The motor is driven by the constant voltage power output from the conversion means, and the sprayer can be used. The conversion means outputs a constant voltage of electric power to the motor regardless of the battery voltage of the battery pack.

  The power tool of the present invention includes a battery unit capable of selectively connecting a plurality of battery packs having different battery voltages, and a motor driven by power supply from the battery unit, and the battery unit includes the battery voltage. Is converted to a predetermined voltage, and the converter operates to supply a constant voltage to the motor regardless of the battery voltage.

  Preferably, the conversion means includes a switching element connected in series with the motor, and the battery voltage is stepped down and output by a switching operation of the switching element.

  According to the above configuration, when the battery pack is connected and becomes operable by a user's operation, the conversion unit operates to convert the output voltage from the battery pack and supply a constant voltage to the motor. The motor is driven by the constant voltage output from the conversion means, and the power tool can be used. Moreover, the motor is driven when the conversion means steps down the battery voltage and outputs a constant voltage by the switching operation.

  According to the present invention, a sprayer can be operated by selectively connecting a plurality of types of battery packs having different battery voltages. Moreover, even if the battery voltage is different, a constant voltage of electric power can always be supplied to the motor, and the electric tool and the sprayer can be stably operated regardless of the battery voltage of the connected battery pack.

The circuit block diagram of the sprayer which is one Embodiment by this invention. The front view of the sprayer which is one Embodiment by this invention. The side view of the sprayer shown in FIG. The figure which shows the battery unit used for the sprayer shown in FIG.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  First, with reference to FIG.2 and FIG.3, the structure of the sprayer 100 by this invention is demonstrated. The sprayer 100 includes a power tool main body 1 as a main body, a tank 101 that contains liquid such as water and agrochemicals, and a cap 102 for a storage port that is detachably attached, and the liquid stored in the tank 101 is made into a mist. A spray tube 104 for output is provided. The sprayer 100 is carried on the back of an operator, so a belt 105 for carrying the back is attached to the tank 101. Further, a battery unit 4 including a battery pack 6 serving as a drive source is detachably attached to the electric tool main body 1.

  When the operator carries the power tool main body 1 and operates the trigger switch 2 attached to the spray tube 104, liquid is ejected from the tip of the spray tube 104. The liquid injection amount can be adjusted by an adjustment switch 106 provided in the battery unit 4. The adjustment switch 106 is provided with a high pressure switch and a low pressure switch, and the injection amount can be changed by selectively turning on either one.

  Next, the configuration of the battery unit 4 will be described with reference to FIG. The battery unit 4 is detachably attached to the electric tool main body 11. A plurality of types of battery packs 6 can be selectively and detachably attached to the battery unit 4. In the battery unit 4, the voltage switching lever 4 a is switched according to the type of the battery pack 6 to be connected, for example, the rated voltage (14.4 V or 18.0 V). Although FIG. 4 shows a state where the battery pack 6 is attached to the battery unit 4, the battery pack 6 may be covered with a cover serving as a lid attached to the battery unit 4. In this case, the voltage switching lever 4a is configured to be attached to the cover side as a fixing mechanism, and can be configured to restrict the opening and closing of the cover by the switching lever 4a. For example, when the lever 4a is set at the position of the rated voltage (14.4V or 18.0V) of the battery pack 6, the cover is restricted from being opened (maintained closed). On the other hand, when the lever 6a is set at a position other than the rated voltage position, the cover can be opened. The lever 4a is set at the position of the rated voltage or the like by rotating clockwise or counterclockwise in the figure.

  Next, the circuit configuration of the electric power tool (atomizer) 100 and the battery unit 4 will be described with reference to FIG. As shown in FIG. 1, the power tool 100 includes a power tool main body 1 and a battery unit 4 that can be attached to the power tool main body 1. The electric tool main body 1 includes a motor 1a electrically connected between a pair of input terminals 3a and 3b, and a trigger switch 2 for turning on / off power supply to the motor 1a. The trigger switch 2 has one end connected to the motor 1a and the other end connected to the signal terminal T2.

  The battery unit 4 includes a pair of output terminals 5 a and 5 b, a battery pack 6, and a control circuit 7. The battery pack 6 is detachably attached to the battery unit 4, and includes a battery cell portion 6a in which a plurality of secondary battery cells 6a are connected in series, and a battery type determination resistor 6b connected in series to the battery cell portion 6a. Have The battery type discrimination resistor 6b is connected to a microcomputer 13 described later via a signal terminal T. In the battery cell unit 6a, the configuration such as the number of secondary battery cells connected in series and the number of secondary battery cells connected in parallel depends on the type of the secondary battery cell and the use of the power tool main body 1. Can be selected as appropriate. The battery type discrimination resistor 6b is a type of secondary battery cell such as a lithium ion battery cell (3.6V / cell) or a nickel cadmium battery cell (1.2V / cell) as battery voltage detection means or battery type discrimination means. Or, it has a resistance value corresponding to the configuration of the battery cell portion 6a. In the present embodiment, the battery pack 6 having a battery voltage rating of 14.4V and the battery pack having a battery voltage rating of 18.0V can be selectively used. That is, the battery unit 4 can detachably mount a plurality of battery packs 6 having different rated voltages and battery types.

  The control circuit 7 includes an FET 10, a current detection resistor 9, an overcurrent detection circuit 14, a voltage detection circuit 12, a microcomputer 13, and a switch circuit 15.

The FET 10 is a switching element that opens and closes a current path L that is formed to supply power to the motor 1a including the battery cell portion 6a as a conversion means. In the FET 10, a switching operation is performed by PWM by the microcomputer 13.
The current flows from the positive terminal of the battery pack 6 to the output terminal 5a, the input terminal 3a, the motor 1a, the input terminal 3b, the output terminal 5b, the FET 10, the current detection resistor 9, and the negative terminal of the battery pack 6 in this order. L is formed.

  The current detection resistor 9 has one end 9 a connected to the negative electrode side of the battery pack 6 and the other end 9 b connected to the FET 10 and is inserted into the current path L. The current detection resistor 9 detects the output current (load current) flowing from the battery cell unit 6 a and outputs the detection result toward the overcurrent detection circuit 14. The current detection resistor 9 outputs a voltage drop caused by the flow of the output current as a current value.

  Based on the output current from the battery cell unit 6a, the overcurrent detection circuit 14 detects the immobilization of the motor 1a due to overload, that is, the lock, and also detects the short circuit of the current path L, that is, the short circuit. The overcurrent detection circuit 14 includes four operational amplifiers 14 a, 14 b, 14 c and 14 d and a latch circuit 16. The operational amplifier 14a has an inverting input terminal connected to one end 9a of the current detection resistor 9 via a resistor 14i, and a non-inverting input terminal connected to the other end 9b of the current detection resistor 9 via a resistor 14k. The output terminal of the operational amplifier 14a is connected to the inverting input terminal via the resistor 14l and to the non-inverting input terminal of the operational amplifier 14c.

  The operational amplifier 14c receives the first reference potential at the inverting input terminal. The first reference potential is generated by dividing the reference potential Vs by the resistors 14r and 14s, and corresponds to a so-called short current value (short current threshold) that determines the occurrence of a short circuit. The output terminal of the operational amplifier 14c is connected to the latch circuit 16 via the diode 14f. Further, by connecting the resistor 14t in parallel with the resistor 14s in accordance with a signal from the microcomputer 13, the first reference potential can be lowered to change the short-circuit current value (short-circuit current threshold), specifically, reduce it. . The latch circuit 16 outputs HIGH as an output signal in a normal operation. However, the latch circuit 16 responds to the output from the operational amplifier 14c when the input potential to the non-inverting input terminal of the operational amplifier 14c exceeds the first reference potential, that is, when occurrence of a short circuit in the current path L is detected. LOW is output as an output signal. Thus, the operational amplifiers 14a and 14c function as a short circuit detection unit.

  On the other hand, the operational amplifier 14b has an inverting input terminal connected to one end 9a of the current detection resistor 9 via a resistor 14h, and a non-inverting input terminal connected to the other end 9b of the current detection resistor 9 via a resistor 14j. The output terminal of the operational amplifier 14b is connected to the inverting input terminal via the resistor 14m, and is connected to the non-inverting input terminal of the operational amplifier 14d via the delay circuit 14u.

  The operational amplifier 14d receives the second reference potential at its inverting input terminal. The delay circuit 14u includes a resistor 14n and a capacitor 14e, and has a function of delaying at least a predetermined time that the output signal of the operational amplifier 14b is input to the operational amplifier 14d. This predetermined time corresponds to a dead time from when the motor 1a is locked until it is detected. The second reference potential is generated by dividing the reference potential Vs by the resistors 14o and 14p, and corresponds to a so-called lock current value (lock current threshold) that determines whether the motor 1a is locked. The output terminal of the operational amplifier 14d is connected to the latch circuit 16 via the diode 14g. Further, by connecting the resistor 14q in parallel with the resistor 14p in accordance with a signal from the microcomputer 13, the lock current value (lock current threshold) can be changed, for example, reduced by lowering the second reference potential. The latch circuit 16 outputs HIGH in normal operation. However, in response to the output from the operational amplifier 14d when the input potential to the non-inverting input terminal of the operational amplifier 14d exceeds the second reference potential, the latch circuit 16 outputs LOW. That is, the operational amplifiers 14b and 14d function as motor lock detection means.

  In the overcurrent detection circuit 14, the lock current value (lock current threshold) is set smaller than the short current value (short current threshold). If the lock current threshold and the short current threshold are the same, and the overcurrent detection circuit 14 does not include the delay circuit 14u), an excessive start-up current that occurs transiently when the motor 1a is started is short-circuited. The detection means detects that a short circuit has occurred, and as a result, the current path L including the motor 1a may be interrupted. Therefore, in order to distinguish between the lock current and the short-circuit current, two of the short-circuit (short-circuit) current threshold and the lock current threshold are provided separately. And in order to prevent a short circuit detection means detecting a starting current etc. as a short circuit current, the short circuit (short circuit) current threshold value is set larger than a lock current threshold value.

  In the present embodiment, the delay circuit 14u is not provided on the short-circuit detection means side, and the delay circuit 14u is provided only on the lock detection means side. The delay circuit is not provided on the short-circuit detection means side because the short-circuit current has a larger amount of current than the lock current and the start-up current, so that the current path L is quickly opened to protect the current path L and the like. This is to cut off the current.

  The voltage detection circuit 12 detects the battery voltage of the battery cell unit 6 a and outputs the detected battery voltage to the microcomputer 13.

  The microcomputer 13 can be operated by power supply (reference potential Vs, for example, 5 V) from the battery cell unit 6 a via the constant voltage circuit 11. The microcomputer 13 discriminates the type of the battery cell and the configuration of the battery pack 6 by using the battery type discrimination resistor 6b, and supplies the overcurrent detection circuit 14 of the resistors 14t and 14q according to the type of the battery cell and the configuration of the battery pack 6. Sets the presence or absence of electrical connection. If the battery voltage of the battery pack 6 is 18.0 V, the microcomputer 13 does not electrically connect the resistors 14 t and 14 q to the overcurrent detection circuit 14.

  On the other hand, if the battery voltage of the battery pack 6 is 14.4 V, the resistors 14t and 14q are electrically connected to the overcurrent detection circuit 14 to reduce both the short current value (threshold value) and the lock current value (threshold value). . The microcomputer 13 controls the switching operation of the FET 10 to control the output current from the battery pack 6. Depending on the type (rated voltage or cell type) of the battery pack 6, only one of the resistors 14t and 14q may be connected in parallel from the corresponding resistor 14s or 14p. Furthermore, if a plurality of resistors that can be connected in parallel with the resistors 14s and 14p are provided, the battery unit 4 can correspond to many types of battery packs 6.

  The switch circuit 15 includes FETs 15 a and 15 b and controls power feeding to the microcomputer 13. The FET 15a has a source connected to the positive electrode side of the battery cell unit 6a, a drain connected to the constant voltage circuit 11, and a gate connected to the source of the FET 15b via a resistor 15d. The source and gate of the FET 15a are connected via a resistor 15c. The FET 15b has a drain connected to the reference potential G, and a resistor 15f and a capacitor 15g are connected in parallel between the gate and the drain. Further, the gate of the FET 15b is connected to the signal terminal T2 through the resistor 15e and is connected to the output terminal of the latch circuit 16.

  Next, power supply to the electric tool main body 1 by the battery unit 4 will be described.

  When the battery unit 4 to which the battery pack 6 having a battery voltage of 18V is connected is connected to the power tool body 1, the input terminals 3a and 3b of the power tool body 1 and the output terminals 5a and 5b of the battery unit 4 are connected to each other. The Further, the signal terminals T2 are also connected. In order to use the power tool 100, the trigger switch 2 is turned on. When the trigger switch 2 is turned on, the battery voltage of the battery pack 6 is applied to the gate of the FET 15b via the trigger switch 2 of the electric power tool body 1 and the resistor 15e, the FET 15b is turned on, and the FET 15a is turned on. That is, the switch circuit 15 is turned on, and the battery voltage of the battery pack 6 is supplied to the constant voltage circuit 11 through the FET 15a. Since the constant voltage circuit 11 outputs an operating voltage (for example, 5 V) of the microcomputer 13 and starts power feeding to the microcomputer 13, the microcomputer 13 is activated.

  When activated, the microcomputer 13 reads the resistance value of the battery type determination resistor 6b via the signal terminal T, and determines the battery voltage of the battery cell unit 6a and the type of the battery cell. In accordance with the determined battery voltage and the type of battery cell, the microcomputer 13 causes the FET 10 to perform a switching operation to start power supply to the motor 1a, and the overcurrent detection circuit 14 detects the lock and short circuit of the motor 1a. Set the motor lock current value and the short current value. In the present embodiment, for example, when the battery voltage is 18.0 V, the resistors 14 t and 14 q are electrically disconnected from the overcurrent detection circuit 14 by the signal from the microcomputer 13 to obtain the motor lock current value and the short current value. Set each higher. When the battery voltage is 14.4 V, which is lower than 18.0 V, the resistors 14 t and 14 q are electrically connected to the overcurrent detection circuit 14 by a signal from the microcomputer 13, that is, parallel to the corresponding resistors 14 s and 14 p, respectively. The motor lock current value and the short circuit current value are set lower than in the case of 18V. In the present embodiment, the rated voltage of the motor 1a is 12V. Therefore, the microcomputer 13 performs switching control of the FET 10 based on the battery type information (battery voltage, battery cell type) from the battery type determination resistor 6b, and outputs the voltage by reducing the battery voltage to 12V.

  In addition, when power supply to the motor 1a is started, an output current having a current amount substantially equal to or exceeding the lock current as an activation current may instantaneously flow through the current path L. However, in order to turn off the FET 10 by detecting the lock current, the delay circuit 14u needs to maintain the lock state for at least the first predetermined time from the occurrence of the lock. By detecting the current, the power supply to the motor 1a is prevented from being cut off. Further, not only when the motor 1a is started but also when the current instantaneously rises above the lock current threshold while the motor 1a is being driven, the current path L is not immediately interrupted, but at least for a predetermined period. A dead period for delaying detection of occurrence of lock is provided. As a result, it is possible to overlook the transient current rise with little risk of damaging the components and the like, and the work efficiency can be improved.

  On the other hand, when the trigger switch 2 is turned on, an output current corresponding to the switching operation of the FET 10 flows through the current path L including the motor 1a. The output current is continuously detected by the current detection resistor 9. The overcurrent detection circuit 14 detects the current flowing through the current path L by the current detection resistor 9. Further, the microcomputer 13 continuously monitors the lock of the motor 1a and the occurrence of the short circuit of the current path L by the output from the overcurrent detection circuit 14.

  For example, when the input terminals 3a and 3b or the output terminals 5a and 5b are short-circuited for some reason and an overcurrent exceeding a preset short-circuit current value (threshold) flows through the current path L, the overcurrent is The overcurrent detection circuit 14 detects the short current. As soon as a short current is detected, the output of the latch circuit 16 switches from HIGH to LOW, the FET 15b of the switch circuit 15 is turned off, and then the FET 15a is turned off. Therefore, since the power supply to the microcomputer 13 is forcibly cut off, the FET 10 is forcibly turned off, the current path L is cut off, and the output current is zero, that is, no current flows.

  On the other hand, when the motor 1a is locked, at least a first predetermined period is required to switch the output of the latch circuit 16 from HIGH to LOW due to the delay circuit 14u. Therefore, when the locked state of the motor 1a continues for at least the first predetermined period, the output of the latch circuit 16 switches from HIGH to LOW, and the power supply to the microcomputer 13 is forcibly cut off as in the case of a short circuit. The FET 10 is turned off, the current path L is cut off, and the output current becomes zero. On the other hand, although the lock of the motor 1a has occurred, if the lock of the motor 1a is released before the first predetermined time elapses, the output current decreases from the lock current value (becomes smaller than the lock current threshold). Therefore, the output of the latch circuit 16 maintains HIGH without switching to LOW. Therefore, the FET 10 can continue the switching operation and continue to supply power to the motor 1a.

  Further, both the short circuit and the motor lock are detected in an analog manner using an operational amplifier, and the current path L is opened by forcibly cutting off the power supply to the microcomputer 13 by the latch circuit 16 and the switch circuit 15. Therefore, the current path L can be opened quickly. That is, the current path L can be interrupted without depending on the processing speed of the microcomputer 13.

  Furthermore, when the electric tool 100 is overloaded and the motor 1a continues to be locked for at least a predetermined time, or when a short circuit of the current path L occurs, the motor 1a can be reliably stopped. Damage to the battery pack 6 and the motor 1a due to overload can be suppressed. Thus, since the occurrence of motor lock and short circuit is detected independently in the overcurrent detection circuit, the overload state can be detected reliably.

  In addition, since the electric power tool 100 can change the detection value (threshold value) of both the lock current and the short current according to the battery voltage of the battery pack 6, the electric power included in the electric tool and the battery pack including the motor can be changed. Components can be efficiently protected from locks and short circuits. Furthermore, since the battery unit 4 is not provided with a booster circuit, the nebulizer 100 can be configured easily.

  Further, in the above embodiment, the sprayer 100 can be used by selectively connecting a plurality of types of battery packs having different battery voltages to the sprayer 100. Even when the battery voltages of the connected battery packs are different, since the battery voltage is converted into a constant voltage by the converting means and the constant voltage power is supplied to the motor 1a of the sprayer 100. Can be used stably.

  In the above embodiment, the overcurrent detection circuit 14 is provided inside the battery unit 4, but it can also be provided inside the electric power tool body 1 or inside the battery pack 6. Further, the resistance connected in parallel with the resistors 14p and 14s may be increased so that the threshold values of the lock current and the short current can be changed in a plurality of stages.

1 Main Body 1a Motor 4 Battery Unit 6 Battery Pack 6b Battery Type Discriminating Resistance 13 Microcomputer

Claims (6)

Conversion means for converting the battery voltage of the battery pack and outputting power of a desired voltage;
Battery voltage detection means for detecting the battery voltage;
A motor driven by electric power output from the conversion means;
The sprayer is characterized in that a plurality of types of battery packs having different battery voltages can be selectively electrically connected to the conversion means.   The sprayer according to claim 1, wherein the conversion unit outputs electric power having a constant voltage regardless of the battery voltage.   The sprayer according to any one of claims 1 and 2, wherein the conversion means steps down and outputs the battery voltage. The battery pack further includes a body on which the battery pack is detachably attached,
The main body has a lid portion that covers the battery pack,
The sprayer according to any one of claims 1 to 3, further comprising a fixing mechanism that fixes a lid portion of the battery pack to the main body in a state in which the battery pack is covered. A battery unit capable of selectively connecting a plurality of battery packs having different battery voltages;
A motor driven by a power supply output from the battery unit;
With
The battery unit has conversion means for converting the battery voltage into a predetermined voltage,
The electric power tool characterized in that the conversion means operates to supply a constant voltage to the motor regardless of the battery voltage. The conversion means includes a switching element connected in series with the motor,
6. The electric tool according to claim 5, wherein the battery voltage is stepped down and output by a switching operation of the switching element.

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