JP2008264962A - Electric tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power tool capable of determining properly battery replacement timing or charging timing. <P>SOLUTION: The power tool as a driver drill 1 is arranged so that a battery 4 is mounted removably in a housing 2 and equipped with an electric motor 3 operated by electric power supplied by the battery 4 and an illuminating means (LED 36 and prism 37) to emit light upon receiving the supply of the power from the battery 4, wherein a control means is installed which changes the light emitting state of the illuminating means according to a residual quantity of the battery 4. The control means changes the light emitting state of the illuminating means in compliance with a voltage of the battery and/or an accumulated value of a current from the battery 4 and the current feeding time. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cordless electric tool that changes a light emitting state of a light emitting unit in accordance with a remaining amount of a battery.

  For example, a cordless hand-held electric tool such as a driver drill is configured such that a battery is detachably attached to a housing, and an electric motor driven by power supplied from the battery is accommodated in the housing. Is transmitted to the tip tool holding portion, and the tip tool holding portion and a tip tool such as a driver bit attached to the tip tool holding portion are rotationally driven to perform a required operation such as screw tightening.

By the way, in a power tool using a battery as a power source, when the remaining amount of the battery decreases and the power supply voltage drops below a predetermined value, it becomes impossible to continue working, so the battery can be replaced with a new one, It needs to be removed and charged.
JP-A-2005-297121

  However, since the conventional power tool is not provided with means for displaying the remaining battery level, the operator cannot properly determine the battery replacement time or the charging time, and the battery runs out. Otherwise, the battery could not be replaced or charged, and the work was interrupted and the work efficiency was poor.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an electric tool that can appropriately determine a battery replacement timing or a charging timing.

  In order to achieve the above object, an invention according to claim 1 is an electric motor that is detachably mounted on a housing and is driven by power supplied from the battery, and power supplied from the battery. In the electric tool provided with the illumination means for irradiating light, a control means for changing a light emission state of the illumination means in accordance with a remaining amount of the battery is provided.

  According to a second aspect of the present invention, in the first aspect of the present invention, the control unit changes a light emission state of the illumination unit according to a voltage of the battery.

  The invention according to claim 3 is the invention according to claim 1 or 2, characterized in that the control means changes the light emission state of the illumination means according to the integrated value of the current of the battery and the energization time. To do.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the light emitting source of the illuminating means is constituted by an LED.

  According to the first aspect of the present invention, the remaining amount of the battery can be recognized based on the light emission state of the illumination means, and the battery replacement time or charging time can be appropriately determined. Accordingly, there is no possibility that the battery runs out during the work and the work is not interrupted, and the work efficiency is improved.

  According to the second aspect of the present invention, since the light emission state of the illumination unit is changed by the voltage that changes depending on the battery remaining amount, the battery remaining amount can be visually confirmed by the light emission state of the illumination unit. Therefore, it is possible to appropriately determine the replacement time or the charging time.

  According to the third aspect of the present invention, the light emission state of the illumination unit is changed by the integrated value of the current and the energization time that change depending on the remaining battery level, so the remaining battery level is visually confirmed by the light emission state of the illumination unit. The battery replacement time or charging time can be appropriately determined.

  According to the fourth aspect of the present invention, since the light source of the illuminating means is configured by the LED that outputs light with high luminance, the remaining battery level can be reliably recognized even in a bright place.

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

  1 and 2 are side sectional views of a driver drill as an embodiment of an electric power tool according to the present invention, FIG. 3 is a cutaway front view of the driver drill, and FIG. 4 is a main portion of the driver drill (power transmission mechanism). FIG.

  The driver drill 1 according to the present embodiment includes a resin housing 2 having a T-shape when viewed from the side, and an electric motor 3 as a drive source is accommodated horizontally in a body portion 2A of the housing 2. Yes. Further, a battery 4 is detachably attached to a lower end portion of a handle portion 2B integrally extending downward from the body portion 2A of the housing 2, and power is supplied from the battery 4 to the electric motor 3 at an upper portion of the handle portion 2B. A switch 5 is provided for starting / stopping the electric motor 3 by turning ON / OFF.

  Further, a board 6 connected to the battery 4 is horizontally arranged in a space formed in the lower part of the handle portion 2B of the housing 2, and a lead wire 7 extending from the board 6 is connected via a switch 5. Are connected to the electric motor 3. In addition, an indicator lamp 8 whose light emission state is changed by a load torque or the like is incorporated in the rear surface of the lower portion of the handle portion 2B, and this indicator lamp 8 is connected to the substrate 6 through a lead wire 9. The battery 4 is configured by housing three lithium ion batteries 10 therein.

  On the other hand, the rotation of the output shaft 3a of the electric motor 3 accommodated in the body portion 2A of the housing 2 is decelerated by the planetary gear mechanism 11 constituting a three-stage reduction mechanism and transmitted to the output shaft 12, and the output shaft 12 The tip tool holding portion 12a at the tip portion (the left side in FIGS. 1 and 2 is the front) is rotationally driven at a predetermined speed and torque.

  By the way, the driver drill 1 according to the present embodiment is provided with a torque adjustment mechanism 13, and this torque adjustment mechanism 13 is a cylindrical shape that is rotatably attached to the front end of the body portion 2 </ b> A of the housing 2. The maximum torque that is covered by the cap 14 and can be transmitted from the electric motor 3 to the output shaft 12 is adjusted by rotating the cap 14.

  Here, the details of the configuration of the power transmission mechanism including the planetary gear mechanism 11 and the torque adjusting mechanism 13 will be described with reference to FIG.

  The planetary gear mechanism 11 is accommodated in a cylindrical gear case 15. The planetary gear mechanism 11 is fixed to the pinion 16 formed on the output shaft 3 a of the electric motor 3 and the inner peripheral portion of the gear case 15. A plurality of planetary gears 18 that mesh with the ring gear 17 is provided, and a carrier 20 is connected to the planetary gears 18 by a shaft 19. Each planetary gear 18 revolves around the pinion 16 while rotating around the shaft 19, and the carrier 20 is rotated by this revolution.

  A sun gear 21 is formed integrally with the carrier 20, and a plurality of planetary gears 23 are meshed with the ring gear 22 fixed to the inner periphery of the sun gear 21 and the gear case 15. The carrier 25 is connected by the shaft 24. Each planetary gear 23 revolves around the sun gear 21 while rotating about the shaft 24, and the carrier 25 rotates by this revolution.

  A sun gear 26 is formed integrally with the carrier 25, and a plurality of planetary gears 28 mesh with the ring gear 27 rotatably held on the inner periphery of the sun gear 26 and the gear case 15. The planetary gear 28 is connected to the output shaft 12 by a shaft 29. Each planetary gear 28 rotates about the shaft 29. When the ring gear 27 is fixed, the planetary gear 28 revolves around the sun gear 26 to transmit the rotation to the output shaft 12, and the fixing of the ring gear 27 is released. In such a case, the rotation is not caused by revolving around the shaft 29, and the rotation is not transmitted to the output shaft 12.

  Next, the configuration of the torque adjustment mechanism 13 will be described.

  A small-diameter cylindrical portion 15a is integrally formed at the front end portion of the gear case 15, and a pressing member 30 is screwed to the outer periphery of the cylindrical portion 15a so as to be movable in the axial direction. Here, the pressing member 31 is spline-fitted to the inner peripheral portion of the cap 14 and can move relative to the cap 14 in the axial direction while rotating integrally with the cap 14. The cylindrical portion 15a of the gear case 15 holds a bearing 31 that rotatably supports the output shaft 12.

  Incidentally, a plurality of engaging claws 27a extending in the axial direction are formed on the front end surface of the ring gear 27, and the balls 32 are in contact with the engaging claws 27a.

  A spacer 33 is fitted into the gear case 15 so as to be movable in the axial direction. One end surface (rear end surface) of the spacer 33 is in contact with the ball 32, and the other end surface (front end surface) of the spacer 33. A ring-shaped clutch plate 34 is in contact with. A coil spring 35 is mounted between the clutch plate 34 and the pressing member 30. Accordingly, the ball 32 is pressed against the front end surface of the ring gear 27 by the coil spring 35.

  By the way, in the present embodiment, the cap 14 is made of transparent or translucent resin, and the LED 36 and the prism 37 constituting the illumination means are arranged inside the cap 14.

  The prism 37 scatters the light emitted from the LED 36 around the entire circumference. As shown in FIGS. 1 and 2, the LED 36 is opposed to the lower portion of the rear end surface of the prism 37. As shown in FIGS. 1 and 2, the lead wire 38 extending from the LED 36 is connected to the substrate 6, and the LED 36 emits high-luminance light when supplied with a current from the battery 4. Then, the light is diffused around by the prism 37 and the entire cap 14 is uniformly emitted.

  When screw tightening is performed using the driver drill 1 configured as described above, a driver bit (not shown) is mounted on the tool holding portion 12a of the output shaft 12, and the operator turns on the switch 5. Then, electric power is supplied from the battery 4 to the electric motor 3, and the electric motor 3 is started. Then, the rotation of the electric motor 3 is decelerated by three stages by the planetary gear mechanism 11, but when the load torque applied to the output shaft 12 is less than the set value, the ring gear 27 of the planetary gear mechanism 11 is pushed by the ball 32. Since it is fixed by pressure and does not rotate, the rotation of the electric motor 3 decelerated by three steps is transmitted to the output shaft 12, and a driver bit (not shown) mounted on the tip tool holding portion 12a rotates at a predetermined speed. A screw (not shown) is screwed into the material to be fastened by the driver bit.

  By the way, when the load torque is applied to the output shaft 12 more than the set value, the ring gear 27 of the planetary gear mechanism 11 is released and the engaging claw 27a gets over the ball 32 and the ring gear 27 rotates. Since the planetary gear 28 rotates only around the shaft 29 and does not revolve, the rotation of the electric motor 3 is not transmitted to the output shaft 12, and an excessive load does not act on the planetary gear mechanism 11 and the electric motor 3. Damage is prevented.

  Thus, if the cap 14 is turned to move the pressing member 30 in the axial direction along the cylindrical portion 15a of the gear case 15, the length of the coil spring 35 is adjusted and the pressing force of the ring gear 27 by the ball 32 is reduced. Therefore, the maximum torque that can be transmitted from the electric motor 3 to the output shaft 12 is adjusted. For example, as shown in FIG. 2, if the pressing member 30 is moved rearward and the coil spring 35 is pressed and contracted, the compression reaction force of the coil spring 35 increases and the pressing force of the balls 32 on the ring gear 27 increases. Therefore, the maximum torque that can be transmitted from the electric motor 3 to the output shaft 12 is set high.

By the way, the present embodiment is characterized in that the light emission state of the LED 36 constituting the illumination means is changed according to the remaining battery level, and an example of a control circuit that changes the light emission state of the LED 36 according to the voltage of the battery 4. FIG. 7 shows an example of a control circuit shown in FIG. 5 or 6 that changes the light emission state of the LED 36 in accordance with the integrated value of the current of the battery 4 and the energization time.
This is done by a control circuit.

  The control circuit shown in FIG. 5 turns on the LED 36 when the voltage of the battery 4 drops below a set value. In this embodiment, two LEDs 36a and 36b having different colors are used.

  When the two-contact type switch 5 is turned on during the screw tightening operation, the electric motor 3 is supplied with power from the battery 4 to start up the electric motor 3, and the current is supplied to one LED lamp 36a to turn on the LED 36a. To do.

In the control circuit, the reference voltage (voltage corresponding to the set value) V _ref is defined by the shunt regulator 39 and input to the comparator 40, while the current voltage of the battery 4 is divided by the resistors R1 and R2. The divided voltage V is input to the comparator 40, and the voltage V is compared with the reference voltage _Vref . When the voltage V is higher than the reference voltage V _ref (V> V _ref ), the other LED 36b is not energized and the LED 36b is not lit.

On the other hand, when the remaining amount of the battery 4 decreases and the voltage drops below the set value and the voltage V becomes smaller than the reference voltage V _ref (V <V _ref ), the other LED 36b is energized. The LED 36b is turned on. Therefore, when the LED 36b is turned on, the light emission color of the cap 14 changes, and the operator can visually confirm that the remaining amount of the battery 4 has decreased due to the change in the light emission color of the cap 14. 4 can be appropriately determined for replacement time or charging time. As a result, the work efficiency is increased without running out of the battery and interrupting the work during the work. In this case, since the LEDs 36a and 36b output high-luminance light, the remaining battery level can be reliably recognized even in a bright place.

  The control circuit shown in FIG. 6 causes the microcomputer 41 to blink the two LED lamps 36a and 36b when the voltage of the battery 4 falls below a set value. In the present embodiment, two LEDs 36a and 36b are used, but only one LED 36a or 36b may be used.

  When the two-contact switch 5 is turned on during the screw tightening operation, the electric motor 3 is powered by the battery 4 and the electric motor 3 is started, and the voltage of the battery 4 is lowered to the power supply voltage of the microcomputer 41 by the regulator 42. And supplied to the microcomputer 41, whereby the microcomputer 41 operates. In FIG. 6, 43 is a capacitor having a smoothing function, and 44 is a reset IC for preventing a malfunction of the microcomputer 41.

The current voltage of the battery 4 is divided by the resistors R1 and R2, and the divided voltage V is input to the microcomputer 41. Then, the microcomputer 41 compares the voltage V with the reference voltage (voltage corresponding to the set value) V _ref, and the remaining amount of the battery 4 is reduced, and the voltage drops below the set value. When it becomes smaller than the voltage V _ref (V <V _ref ), the LEDs 36a and 36b are blinked. Therefore, the operator can know that the remaining amount of the battery 4 is reduced by blinking the LEDs 36a and 36b, and can appropriately determine the replacement timing or the charging timing of the battery 4. As a result, the work efficiency is increased without running out of the battery and interrupting the work during the work. In this case, since the LED lamps 8a and 8b output high-luminance light, the remaining battery level can be reliably recognized even in a bright place.

  The control circuit shown in FIG. 7 changes the light emission state of the two LEDs 36a and 36b of green (G) and red (R) by the microcomputer 41 according to the integrated value of the current and energization time in addition to the voltage of the battery 4. It is a thing.

  That is, the supply current of the battery 4 is detected by amplifying the voltage drop of the shunt resistor R3 by the operational amplifier 45 and inputting it to the microcomputer 41. Then, the microcomputer 41 performs an operation for integrating the product of the detected current and the energization time for each operation, and controls the lighting / extinguishing of the LEDs 36a and 36b according to the integrated value to display the remaining battery level. At the same time, the microcomputer 41 calculates the remaining amount of the battery 4 by detecting the voltage as in the control circuit shown in FIG.

  For example, when the voltage of the battery 4 is low to some extent, it is determined that the remaining amount of the battery is low without adding up the current and the energization time. When the voltage of the battery 4 is medium, the remaining battery level is calculated on the assumption that the voltage is medium.

  Although the present invention has been described with respect to the embodiment in which the present invention is applied particularly to a driver drill, the present invention is similarly applied to an impact driver and any other hand-held power tool to achieve the same effects as described above. Obtainable.

It is side sectional drawing of the driver drill which concerns on this invention. It is side sectional drawing of the driver drill which concerns on this invention. It is a fracture front view of the driver drill concerning the present invention. It is an enlarged detailed view of the driver drill main part (power transmission mechanism part) which concerns on this invention. It is a block diagram of a control circuit. It is a block diagram of a control circuit. It is a block diagram of a control circuit.

Explanation of symbols

1 Driver drill (electric tool)
2 Housing 2A Housing body 2B Housing handle 3 Electric motor 3a Output shaft of electric motor 4 Battery 5 Switch 6 Substrate 7 Lead wire 8 Indicator lamp 9 Lead wire 10 Lithium ion battery 11 Planetary gear mechanism 12 Output shaft 12a Output shaft Tip tool holding portion 13 torque adjusting mechanism 14 cap 15 gear case 15a cylindrical portion of gear case 16 pinion 17 ring gear 18 planetary gear 19 shaft 20 carrier 21 sun gear 22 ring gear 23 planetary gear 24 shaft 25 carrier 26 sun gear 27 ring gear 27a engagement of ring gear Claw 28 Planetary gear 29 Shaft 30 Press member 31 Bearing 32 Ball 33 Spacer 34 Clutch plate 35 Coil spring 36 LED (light emitting source)
37 Prism 38 Lead wire 39 Shunt regulator 40 Comparator 41 Microcomputer 42 Regulator 43 Capacitor 44 Reset IC
45 operational amplifier

Claims (4)

In an electric tool equipped with an electric motor that is detachably mounted on a housing and is driven by receiving power supply from the battery, and an illuminating means that radiates light by receiving power supply from the battery,
An electric tool characterized by comprising a control means for changing a light emission state of the illumination means in accordance with a remaining amount of the battery.   The power tool according to claim 1, wherein the control unit changes a light emission state of the illumination unit according to a voltage of the battery.   2. The electric tool according to claim 1, wherein the control unit changes a light emission state of the illumination unit according to an integrated value of the current of the battery and the energization time. The power tool according to any one of claims 1 to 3, wherein a light emitting source of the illuminating means is constituted by an LED.

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