JP2016010839A - Electric tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric tool capable of displaying an appropriate remaining battery level even if the rated voltage of a battery pack to be mounted changes. A calculation unit 41 lights LEDs 51 to 54 when the output voltage of the battery pack 11 is 19.5 V or more, and LEDs 51 to 54 when the output voltage of the battery pack 11 is 18.6 V or more and less than 19.5 V. When the output voltage of the battery pack 11 is 15.6 V or more and less than 18.6 V, the LEDs 51 and 52 are turned on, and when the output voltage of the battery pack 11 is 14.9 V or more and less than 15.6 V, the LED 51 is turned on. When the battery pack 11 is lit and the output voltage of the battery pack 11 is less than 14.9 V, the LEDs 51 to 54 are turned off. [Selection diagram] Fig. 1

Description

  The present invention relates to an electric tool capable of selectively mounting a plurality of battery packs having different rated voltages.

  2. Description of the Related Art Conventionally, a cordless type electric tool that operates with electric power of a battery pack that is detachably attached is known. The battery remaining amount (remaining capacity) of the attached battery pack is detected based on, for example, the output voltage of the battery pack, and is notified to the user by display means such as an LED. Although the rated voltage of the battery pack varies, it is convenient if a plurality of battery packs having different rated voltages can be selectively mounted on the electric tool.

JP 2011-148064 A

  When the remaining battery level is detected based on the output voltage of the battery pack, even if the output voltage is the same, the amount of the remaining battery level changes if the rated voltage is different. For example, when the motor is not energized (no load), the battery pack with the rated voltage of 18.0V has an output voltage of 18.6V or less and the battery voltage is insufficient, whereas the battery pack with the rated voltage of 14.4V outputs the output voltage. 15.6V or more is close to full charge. However, in the conventional electric tool, the battery remaining amount display corresponds to only one type of rated voltage, and when a battery pack having a different rated voltage is attached, an appropriate remaining amount display cannot be performed.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide an electric tool capable of displaying an appropriate remaining battery level even if the rated voltage of a battery pack to be mounted changes.

One embodiment of the present invention is a power tool. This electric tool
An electric tool capable of selectively mounting a plurality of battery packs having different rated voltages from each other,
A first remaining amount display unit corresponding to a battery pack having a first rated voltage;
A second remaining amount indicator corresponding to the battery pack of the second rated voltage;
A remaining amount display control unit that controls the first and second remaining amount display units based on an output voltage of the attached battery pack.

The remaining amount display control unit controls the remaining amount display unit based on a relationship between an output voltage of the battery pack and a plurality of threshold voltages,
The plurality of threshold voltages may include a first threshold voltage corresponding to the first rated voltage and a second threshold voltage corresponding to the second rated voltage.

Another aspect of the present invention is a power tool. This electric tool
An electric tool capable of selectively mounting a plurality of battery packs having different rated voltages from each other,
A remaining amount indicator,
A remaining amount display control unit that controls the remaining amount display unit based on the relationship between the output voltage of the attached battery pack and a plurality of threshold voltages,
The plurality of threshold voltages include a first threshold voltage corresponding to a first rated voltage and a second threshold voltage corresponding to a second rated voltage.

  The remaining amount display unit may include a first remaining amount display unit corresponding to a battery pack having a first rated voltage and a second remaining amount display unit corresponding to a battery pack having a second rated voltage. Good.

  A plurality of the first and second threshold voltages may exist.

  The minimum threshold voltage included in the first threshold voltage may be greater than the maximum threshold voltage included in the second threshold voltage.

  The remaining amount display control unit may perform remaining amount display control without receiving information indicating the rated voltage of the battery pack in addition to the output voltage of the battery pack.

  It should be noted that any combination of the above-described constituent elements, and those obtained by converting the expression of the present invention between methods and systems are also effective as aspects of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, even if the rated voltage of the battery pack to mount changes, the electric tool which can display an appropriate battery remaining charge can be provided.

The internal block diagram of the electric tool which concerns on Embodiment 1 of this invention. The enlarged view of the brushless motor 2 vicinity of FIG. The control block diagram of the said electric tool. FIG. 4 is an external view of a remaining amount display unit 12 in FIGS. 1 and 3. Explanatory drawing which shows the relationship between the display mode of the residual amount display part 12 of FIG. 4, and LED which lights. The control flowchart which concerns on the battery remaining amount display by the control part 40 of FIG. The external view of the residual amount display part 12 of the electric tool which concerns on Embodiment 2 of this invention. Explanatory drawing which shows the relationship between the display mode of the residual amount display part 12 of FIG. 7, and LED which lights. The circuit diagram of the residual amount display control part of the electric tool which concerns on Embodiment 3 of this invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or equivalent component, member, process, etc. which are shown by each drawing, and the overlapping description is abbreviate | omitted suitably. In addition, the embodiments do not limit the invention but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

Embodiment 1
FIG. 1 is an internal configuration diagram of a power tool according to Embodiment 1 of the present invention. Here, an impact driver will be described as an example of the electric tool. The housing 1 includes a main body body portion 1a, a handle portion 1b, and a battery pack mounting portion 1c. A handle portion 1b extends downward from an intermediate portion of the main body body portion 1a, and the housing 1 is generally T-shaped as a whole. A battery pack mounting portion 1c is provided at the lower end of the handle portion 1b. The handle portion 1b is provided with a trigger switch 10 for the user to control the operation of the electric tool. A plurality of battery packs 11 (for example, battery packs 11 having rated voltages of 18.0 V and 14.4 V) having different rated voltages can be alternatively mounted on the battery pack mounting portion 1c. On the surface of the battery pack mounting portion 1c, a remaining amount display unit 12 to be described later for displaying the remaining battery level (remaining capacity) of the battery pack 11 is provided. The control circuit board 13 on which the control unit 40 shown in FIG. 3 is mounted is stored in the battery pack mounting unit 1c.

  A brushless motor 2 and a rotary striking mechanism are provided in the main body body 1a. That is, in the main body body portion 1 a, the spindle 4 is connected to the brushless motor 2 via a speed reduction mechanism 3 (for example, a planetary gear mechanism), and the hammer 4 is connected to the spindle 4 via a spring 5 (compression spring) and a steel ball 6. Are connected, and an anvil 8 is provided on the tip side of the hammer 7. A tip tool mounting hole 9 for mounting a tip tool such as a driver bit is provided at the tip of the anvil 8. When a user grips the handle portion 1b and pulls the trigger switch 10 during work such as screw tightening, the user can brushlessly remove the battery pack 11 that is detachably attached to the lower end (battery pack attachment portion 1c) of the handle portion 1b. Electric power is supplied to the motor 2, and the spindle 4 and the hammer 7 are rotated by the rotation of the brushless motor 2, and the hammer 7 applies a rotational impact force to the anvil 8. In addition, since the structure and operation | movement of such a rotation impact mechanism are known, the detailed description beyond this is abbreviate | omitted.

  FIG. 2 is an enlarged view of the vicinity of the brushless motor 2 of FIG. The brushless motor 2 is present or extends behind the base portion of the handle portion 1 b of the main body body portion 1 a of the housing 1. A rotor core 22 is provided around the shaft 21. The rotor core 22 is formed, for example, by stacking electromagnetic steel plates into a cylindrical shape. A permanent magnet 23 is inserted and held in the rotor core 22. On the outer periphery of the rotor core 22, the stator core 31 is held by the main body body portion 1 a of the housing 1. A coil 35 is wound around the stator core 31 via an insulator 34.

  FIG. 3 is a control block diagram of the electric power tool of FIG. The brushless motor 2 is a so-called inner rotor type, and the rotor core 22 has a plurality of sets (two sets in this embodiment) of N poles and S poles on the outer peripheral surface by permanent magnets 23 (rotor magnets). Yes. The stator includes a coil 35 (stator coil) made up of star-connected three-phase stator windings U, V, and W and a stator core 31. The control unit 40 includes a calculation unit 41, a rotor position detection circuit 43, a motor rotation number detection circuit 44, a switch operation detection circuit 45, an applied voltage setting circuit 46, a control signal output circuit 47, and a voltage detection circuit 48.

  The three position detecting elements 42 are arranged at predetermined intervals in the circumferential direction, for example, at an angle of 60 °, in order to detect the rotational position of the rotor of the brushless motor 2. The rotor position detection circuit 43 generates a rotation position detection signal based on the signal from the position detection element 42. The motor rotation speed detection circuit 44 detects the rotation speed of the brushless motor 2 based on the rotation position detection signal and generates a rotation speed detection signal. The switch operation detection circuit 45 detects the operation of the trigger switch 10 by the user and generates a switch operation detection signal. The applied voltage setting circuit 46 detects the operation amount of the trigger switch 10 by the user and generates an applied voltage setting signal. The calculation unit 41 causes the control signal output circuit 47 to generate the switching element drive signals H1 to H6 based on the rotation position detection signal, the rotation speed detection signal, the switch operation detection signal, and the applied voltage setting signal, and the stator winding The energization direction and time to U, V, and W are controlled, and the brushless motor 2 is rotationally driven.

  The inverter circuit 47 includes six switching elements Q1 to Q6 such as FETs connected in a three-phase bridge format. The gates of the six switching elements Q1 to Q6 connected in a bridge are connected to the control signal output circuit 47, and the drains or sources of the six switching elements Q1 to Q6 are star-connected stator windings. Connected to U, V, W. The six switching elements Q <b> 1 to Q <b> 6 perform switching operations according to the switching element drive signals H <b> 1 to H <b> 6 input from the control signal output circuit 47, and the DC voltage of the battery pack 11 applied to the inverter circuit 47 is three-phase (U Phase, V phase and W phase) are supplied to the stator windings U, V and W as voltages Vu, Vv and Vw.

  Of the switching element drive signals H1 to H6, signals (H4 to H6) applied to the gates of the low-side switching elements Q4 to Q6 or signals (H1 to H3) applied to the gates of the high-side switching elements Q1 to Q3. ) Is a pulse width modulation signal (PWM signal). By changing the duty of this PWM signal, the power supply amount to the brushless motor 2 is adjusted, and the brushless motor 2 is started, stopped, and rotated. The speed can be controlled. The calculation unit 41 is, for example, a microcomputer, not shown, but a central processing unit (CPU) for outputting a drive signal based on the processing program and data, a ROM for storing the processing program and control data, and data RAM, a timer, etc. are temporarily stored. The control signal output circuit 47 generates a drive signal for alternately switching predetermined switching elements Q1 to Q6 based on the output signal of the rotor position detection circuit 43 according to the control of the arithmetic unit 41. As a result, the predetermined windings of the stator windings U, V, and W are alternately energized, and the rotor of the brushless motor 2 is rotated.

The voltage detection circuit 48 detects the output voltage of the battery pack 11 based on the divided voltage obtained by dividing the output voltage of the battery pack 11 with the resistors R ₁ and R ₂ , and feeds it back to the calculation unit 41. The calculation unit 41 controls the remaining amount display unit 12 according to the detected output voltage of the battery pack 11. That is, the calculation unit 41 functions as a remaining amount display control unit. The remaining amount display unit 12 displays the remaining amount of battery (remaining capacity) of the battery pack 11, and here is constituted by four LEDs 51 to 54 (light emitting unit). The electric power tool of the present embodiment can alternatively be mounted with a plurality of battery packs 11 having different rated voltages, and can display an appropriate remaining amount even when the rated voltage of the mounted battery pack 11 changes. Is.

  FIG. 4 is an external view of the remaining amount display unit 12 of FIGS. 1 and 3. The remaining amount display unit 12 includes a first remaining amount display unit 12a corresponding to the battery pack 11 having a rated voltage of 18.0V and a second remaining amount display unit 12b corresponding to the battery pack 11 having a rated voltage of 14.4V. Including. The first remaining amount display unit 12a and the second remaining amount display unit 12b are separated or partitioned from each other so as to be understood by the user by displaying a rated voltage or the like. The first remaining amount display unit 12 a includes LEDs 53 and 54, and the second remaining amount display unit 12 b includes LEDs 51 and 52.

  FIG. 5 is an explanatory diagram showing the relationship between the display mode of the remaining amount display unit 12 of FIG. The display mode A is when the output voltage of the battery pack 11 is 19.5 V or more (corresponding to the battery remaining amount “high” of the battery pack 11 with the rated voltage of 18.0 V), and the LEDs 51 to 54 are lit (all LED lights up). The display mode B is when the output voltage of the battery pack 11 is 18.6 V or more and less than 19.5 V (corresponding to the remaining battery level “medium” of the battery pack 11 with the rated voltage of 18.0 V), and the LEDs 51 to 53 are lit. The LED 54 is turned off. In the display mode C, when the output voltage of the battery pack 11 is 15.6V or more and less than 18.6V (the remaining battery level of the battery pack 11 having the rated voltage of 18.0V is “small” or the battery pack 11 having the rated voltage of 14.4V Corresponding to the remaining battery level “high”), the LEDs 51 and 52 are turned on, and the LEDs 53 and 54 are turned off. The display mode D is when the output voltage of the battery pack 11 is 14.9 V or more and less than 15.6 V (corresponding to the remaining battery level “medium” of the battery pack 11 with the rated voltage of 14.4 V), the LED 51 is lit, The LEDs 52 to 54 are turned off. The display mode E is when the output voltage of the battery pack 11 is less than 14.9 V (corresponding to the remaining battery level “low” of the battery pack 11 with the rated voltage of 14.4 V), and the LEDs 51 to 54 are turned off (all LED goes off). In the present embodiment, 18.0V corresponds to the first rated voltage, and 19.5V and 18.6V correspond to the first threshold voltage. In addition, 14.4V corresponds to the second rated voltage, and 15.6V and 14.9V correspond to the second threshold voltage. These threshold voltages correspond to + about 8% and + about 3% of the rated voltage.

  FIG. 6 is a control flowchart according to the battery remaining amount display by the control unit 40 of FIG. The voltage detection circuit 48 detects the output voltage of the battery pack 11 and feeds it back to the calculation unit 41 (S1). If the output voltage of the battery pack 11 is 19.5 V or higher (S2, YES), the calculation unit 41 controls the remaining amount display unit 12 according to the display mode A (S3). If the output voltage of the battery pack 11 is not less than 18.6V and less than 19.5V (S4, YES), the calculation unit 41 controls the remaining amount display unit 12 by the display mode B (S5). If the output voltage of the battery pack 11 is not less than 15.6 V and less than 18.6 V (S6, YES), the calculation unit 41 controls the remaining amount display unit 12 according to the display mode C (S7). If the output voltage of the battery pack 11 is 14.9 V or more and less than 15.6 V (S8, YES), the calculation unit 41 controls the remaining amount display unit 12 according to the display mode D (S9). If the output voltage of the battery pack 11 is less than 14.9 V (S8, NO), the calculation unit 41 controls the remaining amount display unit 12 according to the display mode E (S10). The user can know the remaining battery level based on the output voltage of the battery pack 11 when the motor is not energized by checking the remaining capacity display unit 12 when the trigger switch 10 is not operated.

  According to the present embodiment, the following effects can be achieved.

(1) Since the first remaining amount display unit 12a and the second remaining amount display unit 12b corresponding to the battery packs 11 with the rated voltages of 18.0V and 14.4V, respectively, are provided, the calculation unit 41 includes the battery pack. Even if the rated voltage of 11 is not identified, the remaining amount display control according to the rated voltage can be performed based on the output voltage of the battery pack 11. That is, even if the rated voltage of the battery pack 11 to be mounted changes, an appropriate remaining amount display can be performed based on the output voltage of the battery pack 11.

(2) The calculation unit 41 outputs the output voltage of the battery pack 11, the first threshold voltage (19.5V and 18.6V) corresponding to the rated voltage 18.0V and 14.4V, and the second threshold voltage ( 15.6V and 14.9V), the remaining amount display control is performed, so that the rated voltage of the battery pack 11 is determined based on the output voltage of the battery pack 11 without identifying the rated voltage of the battery pack 11. The remaining amount display control can be performed. That is, even if the rated voltage of the battery pack 11 to be mounted changes, an appropriate remaining amount display can be performed based on the output voltage of the battery pack 11.

(3) The calculation unit 41 performs remaining amount display control without identifying the rated voltage of the battery pack 11 (without receiving information indicating the rated voltage of the battery pack 11 in addition to the output voltage of the battery pack 11). The remaining amount display control step is simple and short, and there is no risk of misjudgment of the rated voltage.

Embodiment 2
FIG. 7 is an external view of the remaining amount display portion 12 of the electric power tool according to Embodiment 2 of the present invention. The remaining amount display unit 12 of the present embodiment includes a first remaining amount display unit 12a corresponding to the battery pack 11 having a rated voltage of 18.0V and a second remaining unit corresponding to the battery pack 11 having a rated voltage of 14.4V. The quantity display part 12b partially overlaps. Specifically, the LED 53 belongs to both the first remaining amount display unit 12a and the second remaining amount display unit 12b. That is, the first remaining amount display unit 12a includes LEDs 53 to 55, and the second remaining amount display unit 12b includes LEDs 51 to 53. The first remaining amount display unit 12a is surrounded (partitioned) by a solid line, the second remaining amount display unit 12b is surrounded (partitioned) by a dotted line, and the user can use the first remaining amount display unit 12a and the second remaining amount display unit 12a. The remaining amount display part 12b can be distinguished.

  FIG. 8 is an explanatory diagram showing the relationship between the display mode of the remaining amount display unit 12 of FIG. Each display mode shown in FIG. 8 and the output voltage range of the battery pack 11 corresponding thereto are the same as those in the first embodiment shown in FIG. 5, but the relationship between each display mode and the LED to be lit is different. The calculation unit 41 lights the LEDs 51 to 55 in the display mode A (turns on all the LEDs), lights the LEDs 51 to 54 in the display mode B (turns off the LED 55), and lights the LEDs 51 to 53 in the display mode C. (LEDs 54 and 55 are turned off), LEDs 51 and 52 are turned on in display mode D (LEDs 53 to 55 are turned off), and LEDs 51 are turned on in display mode E (LEDs 52 to 55 are turned off).

  Other points of the present embodiment are the same as those of the first embodiment. The present embodiment can achieve the same effects as those of the first embodiment.

Embodiment 3
FIG. 9 is a circuit diagram of the remaining power display control unit of the electric tool according to the third embodiment of the present invention. In Embodiment 1, the calculation unit 41 functions as a remaining amount display control unit, but in the present embodiment, the comparators 61 to 64 constitute a remaining amount display control unit. Threshold input voltages 14.9V, 15.6V, 18.6V, and 19.5V are input to the inverting input terminals of the comparators 61 to 64, respectively. The non-inverting input terminals of the comparators 61 to 64 are connected to the plus terminal of the battery pack 11. The output terminals of the comparators 61 to 64 are connected to the anodes of the LEDs 51 to 54. The cathodes of the LEDs 51 to 54 are connected to the negative terminal of the battery pack 11. The relationship between the output voltage range of the battery pack 11 and the LED to be lit is the same as that in the first embodiment shown in FIG. Other points of the present embodiment are the same as those of the first embodiment. The present embodiment can achieve the same effects as those of the first embodiment.

  The present invention has been described above by taking the embodiment as an example. However, it is understood by those skilled in the art that various modifications can be made to each component and each processing process of the embodiment within the scope of the claims. By the way. Hereinafter, modifications will be described.

  The power tool is not limited to the impact driver illustrated in the embodiment, and may be another power tool that can selectively mount a plurality of battery packs having different rated voltages. The rated voltage of the battery pack 11 is not limited to 18.0 V and 14.4 V exemplified in the embodiment, and may be other rated voltages such as 10.8 V. When other rated voltages are used, the threshold voltage is also changed to a predetermined ratio with the rated voltage. The remaining amount display unit 12 may be a part of a display unit (display) that displays various types of information.

DESCRIPTION OF SYMBOLS 1 Housing, 1a Main body body part, 1b Handle part, 1c Battery pack mounting part, 2 Brushless motor, 3 Reduction mechanism, 4 Spindle, 5 Spring, 6 Steel ball, 7 Hammer, 8 Anvil, 9 Tip tool attachment hole, 10 Trigger Switch, 11 Battery pack, 12 Remaining capacity display section, 13 Control circuit board, 21 Shaft, 22 Rotor core, 23 Permanent magnet (rotor magnet), 31 Stator core, 34 Insulator, 35 Coil (stator coil), 40 Control section, 41 Calculation Unit, 42 position detection element, 43 rotor position detection circuit, 44 motor rotation speed detection circuit, 45 switch operation detection circuit, 46 applied voltage setting circuit, 47 control signal output circuit, 48 voltage detection circuit, 51-55 LED (light emission) Part), 61-64 comparator

Claims (7)

An electric tool capable of selectively mounting a plurality of battery packs having different rated voltages from each other,
A first remaining amount display unit corresponding to a battery pack having a first rated voltage;
A second remaining amount indicator corresponding to the battery pack of the second rated voltage;
An electric power tool comprising: a remaining amount display control unit that controls the first and second remaining amount display units based on an output voltage of the attached battery pack. The remaining amount display control unit controls the remaining amount display unit based on a relationship between an output voltage of the battery pack and a plurality of threshold voltages,
The electric power tool according to claim 1, wherein the plurality of threshold voltages include a first threshold voltage corresponding to the first rated voltage and a second threshold voltage corresponding to the second rated voltage. . An electric tool capable of selectively mounting a plurality of battery packs having different rated voltages from each other,
A remaining amount indicator,
A remaining amount display control unit that controls the remaining amount display unit based on the relationship between the output voltage of the attached battery pack and a plurality of threshold voltages,
The plurality of threshold voltages include a first threshold voltage corresponding to a first rated voltage and a second threshold voltage corresponding to a second rated voltage.   The remaining amount display unit includes a first remaining amount display unit corresponding to a battery pack having a first rated voltage, and a second remaining amount display unit corresponding to a battery pack having a second rated voltage. The power tool according to claim 3.   The power tool according to any one of claims 2 to 4, wherein a plurality of the first and second threshold voltages are present.   The power tool according to any one of claims 2 to 5, wherein a minimum threshold voltage included in the first threshold voltage is greater than a maximum threshold voltage included in the second threshold voltage.   The said remaining amount display control part performs remaining amount display control, without receiving the information which shows the rated voltage of the said battery pack in addition to the output voltage of the said battery pack. Electric tool.