JP2009072892A - Power tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power tool having improved workability by allowing a worker to selectively set change-over between a single-action mode and a continuous-action mode to reduce the frequency of pushing a switch until setting the desired mode. <P>SOLUTION: The power tool comprises: a motor as a driving source; a motor housing part storing the motor; a handle housing part having one end connected to the motor housing part; a battery provided at the other end of the handle housing part; a spindle to be rotated with the motor; a hammer turnable on the spindle and movable in the axial direction; and an anvil to be hammered and rotated by the hammer. It has the single-action mode in which the hammer hammers the anvil several times and the continuous-action mode in which the hammer continuously hammers the anvil. The first switch for change over between the single-action mode and the continuous-action mode is provided in a housing. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power tool, and more particularly to a structure of a power tool with improved usability with respect to an impact driver's impact force switching function and single / repetitive mode switching function.

An electric power tool such as an impact driver has a motor that is a drive source, a speed reduction mechanism that decelerates the rotation of the motor, and a motor that converts the rotation of the motor decelerated by the speed reduction mechanism into a rotational impact force and transmits it to the tip tool. It is configured to include a mechanism part and the like, and the rotational speed of the motor can be varied according to the stroke of the trigger.
By the way, in impact drivers, etc., the maximum rotation speed (output) of the motor is constant according to the size of the screw, the material of the material to be tightened, the finish level, etc., in order to prevent problems such as cutting the screw head and screwing in too much. A striking force changeover switch is provided to suppress the following.

JP-A-2005-144564

  FIG. 7 is an example showing each mode by operating the striking force changeover switch according to the conventional embodiment. As shown in FIG. 7, in modes 1 to 6, single mode (function that stops automatically after several hits), in modes 7 to 9, timer mode (function that stops automatically after a certain period of time has passed), Mode 10 is a continuous mode (a function that keeps hitting as long as the trigger is continuously pulled). In the timer mode, the time from the start to the stop is longer in the order of modes 7, 8, and 9.

  The hitting force changeover switch is a button that is frequently used during work, and can be changed in 10 steps. The combination of single mode, continuous mode, and timer mode is initially set in these 10 stages, and cannot be set arbitrarily by the user (combination).

  In addition, as the number of setting modes increases, there is a problem that the number of times the switch is pressed increases until the desired mode is set, resulting in poor operability.

  For example, in the work of tightening wood and wood with a long wood screw, if you try to tighten in the single mode so that the head of the screw reaches the same surface as the counterpart material, the single shot mode will end the hitting in the middle of the tightening work, In continuous mode, there was a problem of overtightening.

  Accordingly, an object of the present invention is to provide an electric tool with excellent workability by allowing the operator to arbitrarily set switching between single mode, continuous mode, etc., and reducing the number of times the switch is pressed before setting the mode to be set. It is to be.

  The above-described problems include a motor as a driving source, a motor housing portion that accommodates the motor, a handle housing portion that is connected to the motor housing portion at one end, and a battery that is provided at the other end of the handle housing portion, In a power tool having a spindle rotated by the motor, a hammer rotatable on the spindle and movable in an axial direction, and an anvil which is struck and rotated by the hammer, the hammer moves the anvil several times. This is accomplished by providing the housing with a single mode for striking and a continuous mode in which the hammer continues to strike the anvil, and a first switch for switching between the single mode and the continuous mode is provided on the housing.

  In addition, this is achieved by separately providing the first switch and the second switch for switching the striking force with which the hammer strikes the anvil.

  In addition, the first and second switches are provided on the battery side surface of the handle housing portion, and a panel sheet is provided on the upper surface of the battery of the handle housing portion to indicate that switching has been performed by the first and second switch operations. Is achieved.

  Further, this is achieved by storing the striking force set immediately before the battery is removed from the handle housing part, and the single-shot mode and the continuous mode.

  In addition, by pressing the first and second switches at the same time, this is achieved by providing the initial setting of the hitting force and the function of returning to the single-shot mode and the continuous mode.

  According to the first aspect of the present invention, the single mode and the continuous mode can be switched immediately during work. For example, in the operation of tightening a long wood screw, the initial operation of the screw tightening operation is performed in a continuous mode. When the screw is temporarily stopped before the screw is completely tightened and the first switch is operated, the mode is switched from the continuous mode to the single mode. If the trigger is operated once in this state, a predetermined number of strikes occur and the screw is slightly tightened. If tightening is not enough, operate the trigger once more. In this way, the screw can be securely and securely tightened without failure. When a new screw is tightened, the continuous mode is restored by operating the first switch again. Therefore, it is possible to provide an electric tool having excellent workability.

  According to the second aspect of the present invention, the number of times the switch is pressed until an arbitrary setting is made decreases, and the mode can be quickly switched to an arbitrary mode. For example, if you have been working to tighten a long wood screw until just before, and want to do a work to tighten a short wood screw from now on, just set the appropriate striking force according to the length of the wood screw just by operating the second switch. can do. Therefore, it is possible to provide an electric tool having excellent workability.

  According to the third aspect of the present invention, the panel displaying that the mode is changed by the first and second switch operations is not hidden by the finger. Therefore, the operator can easily check the striking force and check the single shot mode and the continuous mode. Therefore, the operator can provide an electric tool with excellent workability.

  According to the fourth aspect of the present invention, it is not necessary to reset the batting mode, the single shot mode, and the continuous mode at the time of battery replacement, and the operability is improved. Accordingly, it is possible to provide an electric tool having excellent workability.

  According to the fifth aspect of the present invention, even if the mode is a mode in which the switch is frequently pressed until the initial setting is restored, the initial setting can be easily performed. Accordingly, it is possible to provide an electric tool having excellent workability.

  An embodiment of the present invention will be described in detail with reference to FIGS. In the embodiment of the present invention, a cordless impact driver is used as the power tool.

  1 is a partial cross-sectional view according to an embodiment of the present invention, FIG. 2 is a schematic diagram according to an embodiment of the present invention, FIG. 3 is a schematic diagram illustrating an arrangement position of a panel sheet according to the embodiment of the present invention, and FIG. Fig. 5 is an external view showing a striking force changeover switch and a single / repetitive mode changeover switch according to an embodiment of the present invention, Fig. 5 is an example of an external view of a panel sheet, and Fig. 6 is a striking force changeover switch, a single shot / changeover switch. It is one Example which showed each mode by operation of.

  The configuration of the entire tool will be described with reference to FIG. The impact driver 50 according to the first embodiment of the present invention extends from one end (the left end in the drawing) to the other end (the right end in the drawing) along the same direction as the rotation shaft 11 of the brushless motor 3 to be described later. It is extended. The impact driver 50 includes a motor housing portion 50a made of a synthetic resin material that houses the brushless motor 3, and a power transmission housing portion 50b that houses the power transmission mechanism portion 4 that is formed continuously at the other end of the motor housing portion 50a. And a handle housing portion 50c depending from the motor housing portion 50a and the power transmission housing portion 50b. The front end of the power transmission housing 50b projects from the end of the anvil 10, and a tip tool such as a driver bit (not shown) is detachably inserted into the anvil square hole 10a and can be fixed by the mounting member 10b. ing. A bolt tightening bit can also be attached to the anvil square hole portion 10a as another tip tool.

  The motor housing portion 50a has a cylindrical shape, and a brushless motor 3 serving as a driving source is accommodated in the inner peripheral portion thereof.

  A power transmission mechanism portion 4 for transmitting the rotational force of the motor 3 to the anvil 10 as a rotational striking force is accommodated in the power transmission housing portion 50b continuous with the motor housing portion 50a. The power transmission mechanism unit 4 includes a speed reduction mechanism unit including a planetary gear 6 and a ring gear 7, and a spindle 8 and a hammer 9 that is slidable back and forth on the spindle 8 and is provided with a striking force by a spring 5. And an anvil 10 that is provided with a rotating impact force by the hammer 9 and can hold a tip tool (not shown) as described above.

  A battery pack case 1 serving as a driving power source for the brushless motor 3 is detachably mounted on the handle housing portion 50c at the lower end portion of the handle housing portion 50c. The battery pack case 1 accommodates a battery pack body made of a lithium ion battery, a nickel / cadmium battery or the like (not shown). Most of the battery pack main body is inserted and accommodated in the handle housing portion 50c. Alternatively, it is slidably attached to the handle housing portion 50c.

  The battery pack case 1 is electrically connected to the motor drive circuit device 2 via a trigger switch 50d provided in a part of the handle housing portion 50c. The motor drive circuit device 2 is electrically connected to a stator coil 12a (for example, a star-connected three-phase coil) of a brushless motor 3 to be described later, and rotationally drives the rotor 13 of the motor 3.

  In order to electrically drive the motor, an inverter circuit 22 including a known bridge circuit using a switching element for energizing a drive current to the stator coil 12a of the brushless motor 3, and a CPU or the like controlling the inverter circuit 22 The motor drive circuit device 2 is required. In particular, the inverter circuit 22 needs to pass a large drive current through the stator coil 12a, and a large-capacity output transistor such as an IGBT (insulated gate bipolar transistor) operating as a switching element must be used. For this reason, the power loss of the output transistor becomes large and heat generation becomes a problem, so it is necessary to radiate heat. Therefore, the metal (heat dissipating plate) side of the output transistor 21 is disposed at a position close to the air inlet 17 provided in the end wall portion 50e of the motor housing, and no heat dissipating member is provided.

  The inverter circuit board 22 and the control circuit board 41 are connected by a flat cable 39a.

  According to the impact driver 50 configured as described above, when the operator pulls the trigger switch 50d while holding the handle housing portion 50c, the trigger switch 50d is turned on, and the operation of the impact driver 50 can be started.

  During the screw tightening operation, the rotational force of the motor 3 transmitted from the rotary shaft 11 is decelerated by the planetary gear 6 and the ring gear 7, and the rotational force is transmitted to the spindle 8, and the anvil 10 (tip tool) during the screw tightening. When a load torque exceeding a predetermined value is applied, the hammer 9 converts the rotational force into a striking force by the action of the spring 5. Thereby, the hammer 9 can apply a rotational striking force to the tip tool mounted on the anvil 10 and tighten the screw.

  Further, a cooling fan 15 and a sleeve 24 are provided on the rotating shaft 11 of the rotor 13, and the cooling fan 15 and the sleeve 24 rotate simultaneously when the rotor rotates. The front and rear of the rotating shaft 11 of the rotor 13 are supported by bearing members 11a. The stator 12 is provided with an inverter circuit 22 and a cover 25 so that the rotor 13 is sealed.

  An arrow 20 indicates the flow of cooling air.

  Each switch will be described with reference to FIGS. As shown in FIGS. 2 to 4, the striking force changeover switch 33 and the single / repetitive mode changeover switch 34 are configured separately. Further, the striking force changeover switch 33 and the single / repetitive mode changeover switch 34 are connected and fixed to the battery side surface by the controller kumi 31. A panel sheet 32 is provided on the upper surface of the battery. FIG. 5 shows an example of the panel sheet 32. As shown in FIG. 5, a light on / off switch 35, a battery remaining amount display switch 36, a battery remaining amount display panel 38, a single / repetitive mode switching panel 34a, and a striking force switching panel 33a are arranged on the panel sheet 32. Has been.

  By providing the single / continuous mode switching switch 34, the operator can arbitrarily switch between the single mode and the continuous mode. Therefore, it is possible to provide an electric tool having excellent workability.

  FIG. 6 shows an embodiment of each mode by operating the striking force changeover switch 33 and the single / repetitive mode changeover switch 34 of the present invention. The striking force can be switched in four stages, and any striking force can be switched to the single mode or the continuous mode. By providing the striking force changeover switch 33 and the single-shot / repetitive mode changeover switch 34 separately, the number of times of pressing the switch until an arbitrary setting is reduced can be quickly switched to an arbitrary mode. Therefore, it is possible to provide an electric tool having excellent workability.

  Note that the switching of the striking force is not limited to four stages. Further, a timer mode or the like may be added as in the conventional example, and each mode is not limited to the one embodiment shown in FIG.

  If the striking force changeover switch 33 and the single / repetitive mode changeover switch 34 are arranged at positions different from those of other switches and panels, the worker can easily hit the striking force changeover switch 33 and the single / repetitive mode changeover switch 34. Can be switched. Therefore, the arrangement of the switches is not limited to the one embodiment shown in FIG.

Further, a striking force changeover switch 33 and a single / repetitive mode changeover switch 34 that are frequently used during work are provided on the side surface of the battery of the housing. Therefore, when these switches are pressed, the striking force switching panel 33a, the single / repetitive mode switching panel 34a, and the remaining battery level display panel 38 are not hidden by a finger. Therefore, the operator can easily check the striking force and check the single shot mode and the continuous mode. Therefore, it is possible to provide an electric tool having excellent workability.

  Further, if the striking force changeover switch 33, the single / repetitive mode changeover switch 34, and the battery remaining amount display switch 36 are all disposed on the side surface of the battery, the usability is further improved. Since it is not a frequently used switch, there is no particular problem even if it is arranged on the same plane as the striking force switching panel 33a, the single / repetitive mode switching panel 34a, and the battery remaining amount display panel 38.

  In the cordless type impact driver, the battery pack 1 is used as a driving power source. Therefore, as soon as the remaining battery level is exhausted, it must be replaced with a charged battery pack 1. Therefore, the hitting mode and the single / repetitive mode set immediately before the replacement of the battery pack 1 are stored in the microcomputer software built in the controller cum 31. By doing so, it is not necessary to reset the batting mode and the single-shot mode and the continuous mode when replacing the battery, and the operability is improved. Accordingly, it is possible to provide an electric tool having excellent workability.

  Also, when the impact force switch 33 and the single / repetitive mode switch 34 are simultaneously pressed in the microcomputer software, the mode is set to return to the initial setting so that the switch is frequently pressed until the initial setting is restored. However, the initial setting can be easily made. Accordingly, it is possible to provide an electric tool having excellent workability. For example, for example, when there are 10 stages of impact force switching and the impact force is to be changed from 4 to impact force 2, the impact force switch 33 and the single / repetitive mode switch 34 are simultaneously pressed to return to the initial setting and then operated. The number of times of pressing decreases.

  In the embodiment of the present invention, the cordless type impact driver is used as the power tool. However, the present invention can be similarly applied to other power tools.

  Moreover, although it demonstrated using the impact driver mounted with a brushless motor, it is the same also about the motor with a brush, and is not limited to the electric tool mounted with a brushless motor.

The fragmentary sectional view concerning the embodiment of the present invention. Schematic which concerns on embodiment of this invention. Schematic which showed the arrangement position of the panel sheet which concerns on embodiment of this invention. The external view which showed the striking force change switch which concerns on embodiment of this invention, and the single shot / repetitive mode change switch. An example of the external view of the panel sheet which concerns on embodiment of this invention. 1 is an example showing each mode by operating a striking force changeover switch and a single shot / changeover switch according to an embodiment of the present invention. One Example which showed each mode by operation of a striking force changeover switch concerning a conventional embodiment.

Explanation of symbols

1 is a battery pack, 2 is a motor drive circuit device, 3 is a brushless motor, 4 is a power transmission mechanism, 5 is a spring, 6 is a planetary gear, 7 is a ring gear, 8 is a spindle, 9 is a hammer, 10 is an anvil, 10a is an anvil square hole part, 10b is a tip tool mounting member, 11 is a rotating shaft, 11a is a bearing member, 12 is a stator, 12a is a stator coil, 12b is an inner peripheral part of the stator, 12c is an outer peripheral part of the stator, 12d is One end of the stator, 12e is the other end of the stator, 12f is a slot of the stator, 13 is a rotor, 13c is a permanent magnet member, 15 is a cooling fan, 16 is a space, 17 is an intake port, 18 is an exhaust port, 19 Is the air passage, 20 is the cooling air (cooling gas), 21 is the output transistor, 21a is the metal (heat sink) side of the output transistor, 22 is the inverter circuit board, and 31 is the controller. -Rakumi, 32 is a panel sheet, 33 is a striking force switching switch, 33a is a striking force switching panel, 34 is a single / repetitive mode switching switch, 34a is a single / repetitive mode switching panel, 35 is a light on / off switch, 36 is a battery Remaining amount display switch, 37 is a batting changeover display panel, 38 is a battery remaining amount display panel, 50 is a power tool (impact driver), 50a is a motor housing portion, 50b is a power transmission housing portion, 50c is a handle housing portion, and 50e is It is an end wall part of a motor housing.

Claims (5)

A housing;
A motor housed in the housing;
An impact mechanism for converting the continuous rotation operation of the motor into a striking operation which is an intermittent rotation operation;
A tip tool that outputs the impact motion;
A trigger switch that has a trigger and changes the power supplied to the motor by operating the trigger from the outside;
In the electric tool with
When it is detected that the hitting operation has reached a predetermined number of times, a first switch that selectively switches between a single mode that stops the motor and a continuous mode that does not limit the number of hits can be operated from the outside. An electric tool provided on a surface of the housing.   The power tool according to claim 1, wherein the first switch and a second switch for switching a striking force with which the hammer strikes the anvil are provided separately.   The first and second switches are provided on the battery side surface of the handle housing portion, and a panel sheet is provided on the upper surface of the battery of the handle housing portion to indicate that switching has been performed by the first and second switch operations. The electric tool according to claim 1 or 2, wherein   The power tool according to claim 1 or 2, wherein the striking force set immediately before the battery is removed from the handle housing portion and the single-shot mode and the continuous mode are stored.   3. The electric tool according to claim 1, further comprising a function of returning the initial setting of the impact force and the single-shot mode and the continuous-shot mode by simultaneously pressing the first and second switches.

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