JP2008272880A - Hammering tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an effective technology for constituting a rational switch structure on current-carrying control of a motor, in a hammering tool capable of switching a driving mode of a tool bit. <P>SOLUTION: A first switch operation member 153 is energized to the current-carrying cutoff position side from the current-carrying input position side, and is always positioned in a non-input position, and is allowed for input operation to an input position by fingers when a mode switching member 165 is placed on the first driving mode side, and is fixed to the input position when the mode switching member 165 is placed on the second driving mode side. A second switch operation member 155 can perform input operation by fingers for controlling current-carrying and cutoff, and is set so that the current-carrying control is not performed by the input operation when the mode switching member 165 is placed on the first driving mode side, and is set so that the current-carrying control is performed by the input operation when the mode switching member 165 is placed on the first driving mode side. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a striking tool capable of performing a hammering operation on a workpiece (concrete) by causing a tool bit to perform a striking operation.

When working with a hammer tool, for example, an electric hammer drill, hammering in hammer mode where the tool bit strikes in the long axis direction is triggered by a power switch to reduce the burden on the operator. In the hammer drill mode in hammer drill mode where the tool bit performs striking motion and rotation around the long axis, it is preferable that the trigger is placed in the throwing position due to the nature of the work. It is preferable that the operator can freely operate between the non-input position and the input position without being fixed to the position. An electric hammer drill having a mechanism that meets such a demand is disclosed in, for example, Japanese Patent Application Laid-Open No. 2006-957 (Patent Document 1).
The electric hammer drill described in Patent Document 1 has two electric switches for energizing and driving the motor. When the mode switching member is placed on the hammer mode side, the trigger is moved to the closing position and mechanically fixed, whereby one of the electrical switches is turned on. In this state, when the operator turns on the switch operation member to turn on the other electrical switch, the motor is driven to energize. At this time, the operator can continuously perform the hammering operation with the hammer bit by continuously operating the motor without fixing (continuously pulling) the trigger to the closing position with fingers.
On the other hand, when the mode switching member is placed on the hammer drill mode side, the switch operating member is moved to the closing position where the other electrical switch is turned on and mechanically fixed. At this time, the operator can operate the trigger freely between the non-loading position and the loading position, and can drive or stop the motor arbitrarily to perform the hammer drill work intermittently.

In the electric hammer drill described in Patent Document 1, a mode switching member for switching modes and a switch operation member are mechanically coupled, and the switch operation member is mechanically fixed at the input position in accordance with the operation of the mode switching member. Alternatively, the fixing is released. However, in the configuration in which the mode switching member and the switch operation member are mechanically connected, a large number of components are required, so that there is still room for improvement in terms of complicated structure and troublesome assembly. .
JP 2006-957 A

  SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a technique effective in constructing a rational switch structure related to motor energization control in an impact tool capable of switching the drive mode of a tool bit.

  In order to achieve the above object, preferred embodiments of the impact tool according to the present invention include a motor for driving a tool bit linearly in the long axis direction, first and second switch operation members for energizing and shutting off the motor, and A mode switching member is provided for switching the mode between a first drive mode for arbitrarily driving the tool bit and a second drive mode for continuously driving the tool bit. The “first drive mode” in the present invention refers to a hammer drill operation and an impact operation by an impact operation and a rotation operation on the tool bit by arbitrarily (intermittently) driving the motor according to the operation of the operator. This corresponds to a driving mode in which a hammering operation using only a drill or a drilling operation using only a rotating operation is performed. Further, the “second drive mode” in the present invention means that the hammer is operated only by the striking operation on the tool bit by continuously driving the motor without maintaining the operation of the switch operating member by the operator. The drive mode to be performed corresponds to this.

In a preferred embodiment of the present invention, the first switch operating member is movable between a closing position where current is supplied to the motor and a non-closing position where current is cut off. When the mode switching member is urged toward the closing position and placed in the non-loading position and the mode switching member is placed on the first drive mode side, a closing operation to the closing position by a finger is permitted, and the mode switching member is When placed on the second drive mode side, it is configured to be mechanically fixed at the closing position. On the other hand, the second switch operation member can be turned on with a finger to control energization and interruption of the motor, and the mode switching member is placed on either side of the first and second drive modes. The charging operation is allowed. The second switch operating member is set so that the energization control of the motor by the closing operation is not performed when the mode switching member is placed on the first drive mode side, and the mode switching member is the second switching member. When the motor is placed on the drive mode side, it is set so that the energization control of the motor by the closing operation is performed. Note that the “throwing-in operation with the finger” by the finger of the second switch operation member typically corresponds to a pressing operation, but may be a pulling operation or a rotating operation.
When the mode switching member is in the first driving mode, the energization control of the motor is performed according to the turning operation of the first switch operating member with the fingers, and the mode switching member is set in the second driving mode. In this state, the energization control of the motor is performed according to the turning operation of the second switch operation member with the fingers.

In the present invention, the second switch operating member is configured to be turned on using fingers. In the state where the mode switching member is placed on the first drive mode side, the second switch operation member is set so that the energization control for the motor is not performed even if the turning operation with a finger is performed. In this case, the energization control of the motor is performed by the turning-on operation of the first switch operating member. The first switch operating member is a switch operating member that is biased from the closing position side to the non-closing position side and is always placed on the non-closing position side. Therefore, in the first drive mode, the motor (tool bit) is intermittently driven by appropriately performing the insertion operation and the non-operation operation with the fingers of the first switch operation member, for example, hammer drill work, hammer work or Drilling can be done.
On the other hand, in a state where the mode switching member is placed on the second drive mode side, the first switch operating member is mechanically fixed at the closing position. At this time, the second switch operating member The configuration is such that energization control is performed on the motor by a throwing operation with a finger. Therefore, in the second drive mode, the hammer operation can be performed by continuously driving the motor (tool bit) by operating the second switch operating member. In this case, the energization control of the motor by the turning-on operation of the second switch operation member is configured to be maintained even when the finger is released from the second switch operation member.

  According to the present invention, the second switch operation member is configured to perform energization control of the motor by a closing operation with fingers, and mechanical connection to the mode switching member is not necessary. For this reason, the number of mechanical components is reduced, which simplifies the structure and is effective in improving the assemblability. Further, since the mechanical connecting structure is eliminated, the number of mechanical sliding portions is also reduced, which is effective in preventing malfunction caused by switch operation due to dust generated during hammering or hammer drilling. Further, according to the present invention, in the first drive mode, the energization control of the motor is performed by operating the first switch operating member with a finger, and in the second drive mode, the second switch operating member is operated. The motor is energized and controlled by operating with fingers. That is, since the motor energization control is performed by operating either one of the first and second switch operation members with fingers, the operability is improved.

  According to the further form of the impact tool according to the present invention, the second switch operating member can be moved between the initial position and the input position where the input operation has been performed, and the initial position is always from the input position side. It is configured to be biased to the side and to be placed at the initial position. An electrical switch that outputs a closing signal in conjunction with the closing operation of the second switch operating member to the closing position; and a controller that controls energization of the motor in accordance with the closing signal input from the electrical switch. Have. The control unit is configured to perform energization control of the motor in accordance with the number of times of input signal input from the electrical switch in a state where the mode switching member is placed in the second drive mode. In the present invention, “controlling the energization of the motor according to the number of inputs” typically means that the motor is energized by an odd number (for example, the first) input signal of the electrical switch and the energization is performed. A mode in which the state is maintained until an even number (for example, second) input signal is input corresponds to this. Therefore, as the second switch operation member, a switch operation member of a type that returns to the original initial position (non-input position) when the finger is released after the input operation to the input position is adopted. According to the present invention, in the second drive mode, the control unit reads the electric switch input signal, that is, the second switch operation member input operation, and performs the energization control of the motor according to the number of inputs. Thus, the energization control of the motor can be rationally performed by the turning-on operation of the second switch operation member in the second drive mode.

  According to the further form of the impact tool according to the present invention, the controller erases the switching history of the electric switch in the second drive mode when the energization from the power supply connected to the controller is interrupted. Thus, the reset function for returning to the initial state is provided. By adopting such a configuration, for example, it is possible to prevent the motor from being restarted when an action of pulling out the cord on the tool body side from the outlet and then inserting it again is performed.

  According to the further form of the impact tool which concerns on this invention, it has a tool main body and the hand grip which the operator connected with the end part of the tool bit long-axis direction of a tool main body grips. The handgrip is arranged so as to extend in a direction intersecting the long axis direction of the tool bit, and one end side of the extending direction relative to the tool body is rotated relative to the long axis direction of the tool bit via the rotation shaft. The other end in the extending direction is connected to the tool body via an elastic body. The “elastic body” typically corresponds to a spring or rubber. The mode switching member is mounted on the tool body side. On the other hand, the first switch operating member is configured by a trigger that is moved to the closing position by a finger pulling operation and returned to the non-closing position when the pulling operation is released. The trigger is connected to a linkage member that extends to the tool body side through a connecting portion between the tool body and the handgrip on one end side of the handgrip. The linking member moves the trigger to the closing position in conjunction with the movement operation of the mode switching member that is moved from the first driving mode side to the second driving mode side, and is fixed to the closing position. It was.

  According to the present invention, as described above, the linkage member connected to the trigger extends to the tool body side through the connection portion between the tool body and the handgrip, and the mode switching member is in the second drive mode. When placed on the side, the linkage member moves the trigger to the closing position in conjunction with the mode switching member, and is fixed to the closing position. Accordingly, the hand grip of the vibration isolating structure, that is, one end side in the extending direction is connected to the tool bit long axis direction through the rotating shaft so as to be relatively rotatable, and the other end side in the extending direction is, for example, a spring. It is possible to apply to a striking tool having a handgrip connected to be movable relative to at least the long axis direction (striking operation direction) of the tool bit via an elastic body such as rubber.

  According to the further form of the impact tool according to the present invention, the hand grip has an internal space in which the trigger can be accommodated, and the trigger is accommodated in the internal space in a state where the trigger is fixed at the closing position. According to such a configuration, when the operator grips the hand grip and operates the tool body during the hammering operation in the second drive mode, the trigger does not interfere with the fingers holding the hand grip. Thereby, the operativity at the time of gripping a hand grip and performing a hammer work can be improved.

  According to the further form of the impact tool which concerns on this invention, it has a display part which displays the drive state of a tool bit. Note that “displaying the driving state” in the present invention typically means whether the driving mode of the tool bit is on the side of the first driving mode or the second driving mode. If the second switch operating member is placed on the driving position side, the operation state indicating whether the second switch operating member is placed on the closing position side or the non-closing position side is displayed so that the operator can visually determine This is the case. In addition, as a display mode, typically, display by a light such as a single or a plurality of light emitting diodes or incandescent lamps corresponds to this, and the color changes when the light is turned on, turned off, blinked, or turned on. Each aspect of display etc. is suitably included.

  According to the present invention, in the impact tool capable of switching the drive mode of the tool bit, a technique effective for constructing a rational switch structure related to motor energization control is provided.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. This embodiment will be described using an electric hammer drill as an example of an impact tool. FIG. 1 shows the overall configuration of the electric hammer drill, and FIG. 2 shows the configuration of the main part of the electric hammer drill. As shown in FIG. 1, the electric hammer drill 101 according to the present embodiment generally includes a main body 103 that forms an outline of the electric hammer drill 101, and one end region of the main body 103 in the longitudinal direction (the left side in the drawing). ) Connected to the tool holder 117, a hammer bit 119 detachably attached to the tool holder 117, and a handgrip 109 held by an operator connected to the other end (right side in the figure) of the main body 103 in the major axis direction. It is composed mainly of. The main body 103 corresponds to the “tool main body” in the present invention, and the hammer bit 119 corresponds to the “tool bit” in the present invention. The hammer bit 119 is capable of relative reciprocation in the long axis direction (long axis direction of the main body 103) with respect to the tool holder 117, and the relative rotation in the circumferential direction is restricted. It is held in the state. For convenience of explanation, the hammer bit 119 side is referred to as the front, and the hand grip 109 side is referred to as the rear.

  The main body 103 mainly includes a motor housing 105 that houses the drive motor 111 and a gear housing 107 that houses the motion conversion mechanism 113, the striking element 115, and the power transmission mechanism 141. The drive motor 111 corresponds to the “motor” in the present invention. The drive motor 111 is arranged such that the rotation axis is in a vertical direction (vertical direction in FIG. 1) substantially perpendicular to the long axis direction of the main body 103 (that is, the hammer bit long axis direction). The rotation output of the drive motor 111 is appropriately converted into a linear motion by the motion conversion mechanism 113 and then transmitted to the striking element 115, and is transmitted to the hammer bit major axis direction (left and right direction in FIG. 1) via the striking element 115. Generate impact force. The rotational output of the drive motor 111 is appropriately decelerated by the power transmission mechanism 141 and then transmitted as a rotational force to the hammer bit 119, and the hammer bit 119 is rotated in the circumferential direction.

  The hand grip 109 is formed in a substantially U shape in a side view extending in the vertical direction intersecting the long axis direction of the hammer bit, and one end (lower end) side in the vertical direction is disposed on the motor housing via the rotation shaft 183. The lower end of 105 is connected so as to be rotatable in the front-rear direction, and the other end (upper end) side is connected to the upper rear end of the motor housing 105 via a vibration absorbing coil spring 185. The coil spring 185 corresponds to the “elastic body” in the present invention. Thereby, the transmission of vibration from the main body 103 to the hand grip 109 is reduced. That is, the electric hammer drill 101 according to the present embodiment includes a handgrip 109 having a vibration-proof structure.

  As shown in FIG. 2, the motion conversion mechanism 113 converts the rotational motion of the drive motor 111 into a linear motion and transmits it to the striking element 115. The crankshaft 121 and the crank arm 123 that are driven by the drive motor 111. And a crank mechanism including a piston 125 and the like. The piston 125 constitutes a driver for driving the so-called striking element 115 and can slide in the cylinder 127 in the same direction as the long axis direction of the hammer bit.

  The striking mechanism 115 is slidably disposed on the bore inner wall of the cylinder 127, and striker 129 as a striking element driven linearly through the action of an air spring in the cylinder bore by the sliding motion of the piston 125; While being slidably disposed on the tool holder 117, it is mainly configured by an impact bolt 131 as an intermediate element for transmitting the kinetic energy of the striker 129 to the hammer bit 119.

  On the other hand, the tool holder 117 is configured to be rotatable and is configured to be rotated from the drive motor 111 via the power transmission mechanism 141. As shown in FIG. 2, the power transmission mechanism 141 meshes with the intermediate gear 133 that is rotationally driven by the drive motor 111, the intermediate shaft 135, the first bevel gear 137 that rotates together with the intermediate shaft 135, and the first bevel gear 137. A second bevel gear 139 that engages and rotates around the major axis of the main body 103 is transmitted to the tool holder 117 and further to a hammer bit 119 held by the tool holder 117. introduce.

  In addition, a clutch member 143 that transmits or blocks the rotational output of the drive motor 111 to the hammer bit 119 is interposed between the intermediate gear 133 and the intermediate shaft 135. The clutch member 143 is attached to be slidable in the axial direction while being fixed in the circumferential direction with respect to the intermediate shaft 135, and by sliding along the intermediate shaft 135, the clutch teeth of the intermediate gear 133 are provided. And a power transmission state in which the meshing engagement is released and a power cutoff state in which the meshing engagement is released. FIG. 2 shows the power transmission state.

  The switching operation of the clutch member 143 is performed by operating a mode switching dial 165 that switches the driving mode of the hammer bit 119. The mode switching dial 165 corresponds to the “mode switching member” in the present invention. The mode switching dial 165 is attached to the outside of the motor housing 105 so as to be rotatable in a horizontal plane, and is not shown for convenience in being disposed in the internal space of the main body 103 (gear housing 107) by the turning operation. The clutch switching mechanism is operated, and the clutch member 143 is slid along the intermediate shaft 135 to switch to the power transmission state or the power cutoff state.

  In the present embodiment, although not shown for convenience, the first hammer mode position, the second hammer mode position, and the hammer drill mode position are provided on the outer surface of the main body 103 in the circumferential direction of the mode switching dial 165. The mark which shows is set. That is, the mode switching dial 165 switches the mode between at least the first hammer mode and the second hammer mode for causing the hammer bit 119 to perform only the striking operation, and the hammer drill mode for allowing the hammer bit 119 to perform the striking operation and the rotating operation. (Selection) is possible.

  When the mode switching dial 165 is turned to the first hammer mode position or the second hammer mode position, the clutch member 143 is in a power cut-off state. When the drive motor 111 is energized and driven in this state, only the motion conversion mechanism 113 is driven. The rotation output of the drive motor 111 is transmitted to the motion conversion mechanism 113, and the piston 125 of the motion conversion mechanism 113 performs a reciprocating linear motion in the bore of the cylinder 127. When the piston 125 performs a linear motion, the hammer bit 119 performs a striking operation from the piston 125 through the striker 129 and the impact bolt 131. As described above, in the first hammer mode or the second hammer mode in which the clutch member 143 is in the power cut-off state, the hammer bit 119 performs only the hammering operation (hammer operation) and performs the hammering operation on the workpiece (concrete). Carry out.

  On the other hand, when the mode switching dial 165 is turned to the hammer drill position, the clutch member 143 is in a power transmission state. When the drive motor 111 is energized and driven in this state, the power transmission mechanism 141 is driven in addition to the motion conversion mechanism 113. The rotation output of the drive motor 111 is transmitted to the tool holder 117 and the hammer bit 119 held by the tool holder 117 via the intermediate gear 133, the clutch member 143, the intermediate shaft 135, and the first and second bevel gears 137 and 139. Is done. Thus, in the hammer drill mode in which the clutch member 143 is in a power transmission state, the hammer bit 119 performs an axial striking operation and a circumferential rotational operation (drilling operation), and performs a hammer drilling operation on the workpiece (concrete). To do.

  The drive motor 111 generally includes a first electric switch 151 operated by a trigger-like first switch 153, a second electric switch 175 operated by a second switch 155, and a mode switching dial 165 (substantially Is configured to be energized and controlled by a third electrical switch 177 operated by a slide plate 167) which will be described later. The first to third electric switches 151, 175, and 177 are automatic return switches that are always urged to the off state. As shown in FIGS. 3 and 4, the first electric switch 151 is disposed in the vicinity of the controller 112 that controls the drive motor 111 in the rear end region (the region facing the hand grip 109) in the main body 103. ing. The second electric switch 175 is disposed above the first electric switch 151. Further, the third electrical switch 177 is disposed in the vicinity of the mode switching dial 165. The details of energization control of the drive motor 111 by the first to third electric switches 151, 175, and 177 will be described later.

  Next, an operation unit (switch structure) for operating driving / stopping of the drive motor 111 (hammer bit 119) will be described with reference to FIGS. 3 and 4 show the operation unit as an enlarged cross-sectional view. 5 and 6 are sectional views taken along line XX in FIG. 3, and FIG. 7 is a sectional view taken along line YY in FIG. FIG. 8 is a motor control circuit diagram.

  A trigger-like first switch 153 for turning on / off the first electric switch 151 is provided on the handgrip 109 side, and a second electric switch 175 is turned on / off on the main body 103 side. A lever-like second switch 155 is provided. The trigger-shaped first switch 153 corresponds to the “first switch operation member” in the present invention, and the lever-shaped second switch 155 corresponds to the “second switch operation member” in the present invention. The first switch 153 and the second switch 155 are arranged to face each other in the hammer bit major axis direction (major axis direction of the main body 103), that is, the front-rear direction.

  The first switch 153 is disposed in the internal space of the hand grip 109 having a hollow shape. The first switch 153 extends along the extending direction (vertical direction) of the handgrip 109, and is rotatable in the front-rear direction to the handgrip 109 by the mounting shaft 154 at a substantially central portion in the extending direction. It is installed. The first switch 153 is turned on when the first electrical switch 151 is turned on when the first electrical switch 151 is turned off by an off position (non-insertion position) where the first electrical switch 151 is turned off and the operator's fingers pull the upper side. Rotation operation between the position (loading position) and the position (loading position) is possible, and it is always urged from the on position to the off position by a spring not shown for convenience. Therefore, the upper side of the first switch 153 is held in an off position protruding forward from the front opening of the handgrip 109 when the pulling operation is not performed (see FIG. 4), and is turned on by the finger. The position is set so as to be accommodated in the internal space of the hand grip 109 and to be substantially flush with the outer surface of the front surface of the grip (see FIG. 3).

  The first switch 153 extends downward in the internal space of the handgrip 109 and has an extended end disposed in the internal space of the lower connecting region 109 a that connects the main body 103 and the handgrip 109. The rod 163 is connected to one end (rear end) of the rod 163 so as to be relatively rotatable. The connecting rod 163 extends through the internal space of the lower connecting region 109a to the main body side (front), and the extended end (front end) of the switch lever 159 disposed on the main body 103 side ( The lower end is pivotally connected. The lower connecting region 109a corresponds to the “connecting portion” in the present invention, and the connecting rod 163 corresponds to the “linking member” in the present invention.

  The switch lever 159 is provided as a switch actuating member for actuating the first electric switch 151, and extends in the vertical direction (direction substantially parallel to the first switch 153) intersecting the hammer bit major axis direction, and the main body 103. The mounting shaft 161 is pivotally mounted on the mounting shaft 161 as a fulcrum. When the first switch 153 is turned to the on position by a finger, the turning operation of the first switch 153 is transmitted to the switch lever 159 via the connecting rod 163, and the switch lever 159 is moved to the first position. The operation protrusion 151a of the electric switch 151 is pushed, and thereby the first electric switch 151 is turned on.

  The switch lever 159 extends upward. On the extending side of the switch lever 159, a slide plate 167 that is linearly slid in the hammer bit long axis direction (front-rear direction) by a rotation operation of the mode switching dial 165 is disposed. The slide plate 167 constitutes a switch fixing member that mechanically fixes the first switch 153 in the ON position. When the mode switching dial 165 is placed in the first hammer mode position, the slide plate 167 is rearward (see FIGS. 4 is moved to the right) and moved forward when the mode switching dial 165 is placed in the hammer drill mode position or the second hammer mode position. And it is comprised so that the upper end part 159a of the switch lever 159 may be pushed back at the time of the movement to back. The switch lever 159 whose upper end 159a is pushed is rotated in a direction to turn on the first electric switch 151. The rotation of the switch lever 159 is transmitted to the first switch 153 through the connecting rod 163. That is, when the mode switching dial 165 is placed at the first hammer mode position, the first switch 153 is turned to the on position where the first electric switch 151 is turned on and is mechanically fixed at the on position. It is configured to be. This state is shown in FIG. When the mode switching dial 165 is placed at the second hammer mode position or the hammer drill mode position and the slide plate 167 is moved forward, the fixation of the first switch 153 by the slide plate 167 is released. This state is shown in FIG. The first hammer mode corresponds to the “second drive mode” in the present invention, and the hammer drill mode and the second hammer mode correspond to the “first drive mode” in the present invention.

  As shown in FIGS. 5 and 6, the slide plate 167 has a substantially square opening 167a in plan view, and a plate cam 169 provided on the mode switching dial 165 is engaged with the opening 167a. The slide plate 167 can be moved only in the same direction as the long axis direction of the hammer bit by a slide guide 168 provided on the main body side. The slide plate 167 is opened by a plate cam 169 rotated together with the mode switching dial 165 when the mode switching dial 165 is rotated from the hammer drill mode position or the second hammer mode position to the first hammer mode position. The wall surface in the direction intersecting the long axis direction of the hammer bit 167a is pushed and moved backward (see FIG. 5), and the mode switching dial 165 is rotated from the first hammer mode position to the hammer drill mode position or the second hammer mode position. When it is moved, it is configured to move forward by being pushed by a return spring 166 (see FIG. 6). In FIG. 6, the position of the plate cam 169 in the hammer drill mode is indicated by a solid line, and the position of the plate cam 169 in the second hammer mode is indicated by a two-dot chain line.

  Further, when the mode switching dial 165 is placed in the hammer drill mode position and the second hammer mode position, the slide plate 167 contacts the operation protrusion 177a of the third electric switch 177, and the mode switching dial 165 is in the first hammer mode position. When placed on the slide plate 167, the slide plate 167 is separated from the operation protrusion 177a of the third electric switch 177. That is, the third electrical switch 177 is turned on when pressed by the slide plate 167 and turned off when the slide plate 167 is separated.

  On the other hand, as shown in FIGS. 3 and 4, the second switch 155 is supported at its upper end portion so as to be rotatable in the front-rear direction around the mounting shaft 157 with respect to the main body portion 103, and extends downward. Be present. The second switch 155 is operated by a finger between an OFF position (non-insertion position) as an initial position where the second electric switch 175 is turned off and an ON position (release position) where the second electric switch 175 is turned on. It is possible. The second switch 155 is formed in a vertically long shape having a substantially U-shaped cross section with an opening on the front side, and is turned to the on position by being pushed forward by a finger, and is always held in the off position by a spring 156. Is done. The second electrical switch 175 is turned on when the operation protrusion 175a is pushed by the pushing operation of the second switch 155 with a finger, and is turned off when the pushing operation by the second switch 155 is released (the finger is released). It is said.

  FIG. 8 shows a motor control circuit for controlling the energization / cutoff of current to the drive motor 111. As shown in the figure, the drive circuit 171 of the drive motor 111 is provided with a first electrical switch 151 and a semiconductor switch 173 for power on / off in series. The first electrical switch 151 is turned on / off by the operation of the first switch 153. The semiconductor switch 173 is turned on / off based on a control signal from the controller 112. The first electric switch 151 and the semiconductor switch 173 are turned on / off, whereby the current supplied from the power source 172 is supplied to or cut off from the drive motor 111.

  A second electric switch 175 and a third electric switch 177 are connected to the controller 112, respectively, and an on / off signal of the second electric switch 175 by the operation of the second switch 155 and the rotation of the mode switching dial 165. A mode detection signal (mode determination signal) of the third electrical switch 177 selected by the operation is input. The controller 112 is configured to control on / off of the semiconductor switch 173 via the drive unit 179 based on the on / off signal input from the second electric switch 175 and the mode detection signal input from the third electric switch 177. It is said. The second electric switch 175 corresponds to the “electric switch” in the present invention, and the controller 112 corresponds to the “control unit” in the present invention.

Based on the mode detection signal input from the third electrical switch 177, the controller 112 is set to enable or disable the on / off signal of the second electrical switch 175 by the operation of the second switch 155. . That is, when the first hammer mode is selected by rotating the mode switching dial 165 and an OFF signal is input from the third electrical switch 177, the controller 112 operates the second electrical switch by operating the second switch 155. The on / off state of the semiconductor switch 173 is controlled by the on / off signal 175. That is, the on / off operation of the second switch 155 is validated when the first hammer mode is selected. In addition, when the first hammer mode is selected, the controller 112 counts the number of ON signals of the second electrical switch 175 (the number of pressing operations of the second switch 155) when the second switch 155 is turned on / off. The semiconductor switch 173 is turned on at the second time, and the semiconductor switch 173 is turned off at the even number. For example, in the first turning-on operation of the second switch 155, the semiconductor switch 173 is turned on, and the on state is maintained until the second turning-on operation is performed.
On the other hand, when the hammer drill mode or the second hammer mode is selected and an ON signal is output from the third electrical switch 177, the controller 112 electrically fixes the second electrical switch 175 to the on state and switches the semiconductor switch 173 to the ON state. Operates on. That is, when the hammer drill mode or the second hammer mode is selected, the on / off signal of the second electrical switch 175 by the operation of the second switch 155 is invalidated and the energization control of the drive motor 111 by the turning-on operation of the second switch 155 is prohibited. To do.

  Note that energization of the controller 112 is performed via a power supply unit 178 connected to the controller 112. The power supply unit 178 is connected in series to the first electrical switch 151, and energization is controlled based on the on / off operation of the first electrical switch 151. When the power supply from the power supply unit 178 is cut off, that is, when the first electric switch 151 is turned off, the controller 112 turns on / off the second electric switch 175 in the hammer drill mode and the second hammer mode. Is set to have a reset function for erasing the input history (the number of operations of the second switch 155) and returning to the initial state. For this reason, for example, it is possible to prevent the drive motor 111 from being restarted when the power source 172 is turned on / off, that is, after the cord on the main body side is pulled out from the outlet and then inserted again.

  Further, as shown in FIG. 7, the main body 103 is provided with an operation status display unit 181 that displays an operation status below the second switch 155. The operation status display unit 181 corresponds to the “display unit” in the present invention. The operation status display unit 181 is configured so that the operation status of the electric hammer drill 101 can be confirmed by illuminating the indicator lamp with a light emitting diode (LED), an incandescent bulb, or the like. In the present embodiment, when the first hammer mode is selected by the mode switching dial 165, no light is turned on, that is, the light is turned off, and the hammer mode or the second hammer mode is selected (the first switch 153 is in the ON position). When the semiconductor switch 173 is on, for example, a red light emitting diode is lit, and when the semiconductor switch 173 is off, for example, a blue light emitting diode is lit. .

Next, the operation of the electric hammer drill 101 configured as described above will be described. FIG. 3 shows a state where the first hammer mode is selected by rotating the mode switching dial 165. When the mode switching dial 165 is turned to the first hammer mode position, the slide plate 167 is moved backward by the plate cam 169. Then, as shown in FIG. 5, the slide plate 167 moves away from the third electrical switch 177, the third electrical switch 177 is turned off, and an off signal is output to the controller 112. When the off signal is input from the third electrical switch 177, the controller 112 validates the on / off signal input from the second electrical switch 175 thereafter. Further, when the slide plate 167 is moved rearward, the upper end portion 159a of the switch lever 159 is pushed by the rear end portion of the slide plate 167, and the switch lever 159 rotates clockwise in FIG. The first electrical switch 151 is turned on. This turning operation is transmitted to the first switch 153 via the connecting rod 163, and the first switch 153 is turned to the on position and is fixed to the on position.
That is, when the first hammer mode is selected, the first switch 153 is mechanically fixed at an ON position (trigger lock ON mode) in which the first electric switch 151 is turned ON, and the second electric switch 175 is set. The on / off signal input from is made valid.

  Therefore, when the second switch 155 is pushed forward with a finger in this state, the second switch 155 is turned to the on position with the mounting shaft 157 as the turning center, and the operation protrusion 175a of the second electric switch 175 is pushed. . As a result, the second electrical switch 175 is turned on, and an on signal is output to the controller 112. The controller 112 turns on the semiconductor switch 173 via the drive unit 179 based on the on signal input from the second electrical switch 175. For this reason, the drive circuit 171 of the drive motor 111 becomes a closed circuit, and the drive motor 111 is energized and driven. In the first hammer mode, since the clutch member 143 of the power transmission mechanism 141 is switched to the power cut-off state, the hammer bit 119 performs a hammer operation only by a striking operation. Then, the ON operation of the semiconductor switch 173 is maintained until the second ON signal is input from the second electrical switch 175 as described above. In other words, since the operation is maintained even if the finger is released from the second switch 155, the operator continuously energizes the drive motor 111 without continuing to push the second switch 155, and hammers the workpiece. The hammering operation by the hitting operation of the bit 119 can be performed continuously.

  Next, FIG. 4 shows a state in which the hammer drill mode or the second hammer mode is selected by rotating the mode switching dial 165. When the mode switching dial 165 is rotated to the hammer drill mode or the first hammer mode position, the slide plate 167 is moved forward by the return spring 166. Then, as shown in FIG. 6, the slide plate 167 moves in a direction away from the upper end 159 a of the switch lever 159. For this reason, the mechanical fixation of the first switch 153 is released, and the first switch 153 and the switch lever 159 are returned to the off position by the biasing force of the spring. At this time, since the tip of the switch lever 169 moves in a direction away from the operation protrusion 151a of the first electric switch 151, the first electric switch 151 is turned off. Further, the slide plate 167 moving forward pushes the operation protrusion 177a of the third electric switch 177 at the moving end. As a result, the third electrical switch 177 is turned on.

In this state, when the operator pulls the first switch 153 to the ON position against the urging force of the spring with fingers, the switch lever 159 rotates clockwise with respect to the mounting shaft 161 via the connecting rod 163 in FIG. And the operation protrusion 151a of the first electric switch 151 is pushed. As a result, the first electrical switch 151 is turned on, and the controller 112 is energized via the power supply unit 179. Then, since the ON signal is input to the controller 112 from the third electrical switch 177, the controller 112 electrically fixes the second electrical switch 175 to the ON state based on the ON signal, and turns on the semiconductor switch 173. Make it work. For this reason, the drive circuit 171 of the drive motor 111 becomes a closed circuit, and the drive motor 111 is energized. When the hammer drill mode is selected, since the clutch member 143 of the power transmission mechanism 141 is switched to the power transmission state, the hammer bit 119 performs a hammer drill operation by a striking operation and a rotation operation. When the second hammer mode is selected, since the clutch member 143 of the power transmission mechanism 141 is switched to the power cut-off state, the hammer bit 119 performs a hammer drill operation by a striking operation. When the pulling operation of the first switch 153 by the finger is released, the first switch 153 is returned to the off position by the biasing force of a spring (not shown), and the switch lever 159 also turns off the second electric switch 151 in conjunction with this. Return to the position.
That is, in the hammer drill mode or the second hammer mode, the operator freely operates the first switch 153 between the on position and the off position, and freely operates or stops the hammer bit 119. In addition, hammer drill work or hammer work can be performed intermittently.
In the state where the ON signal is output from the third electrical switch 177, the controller 112 invalidates the ON / OFF signal of the second electrical switch 175 by the operation of the second switch 155, and turns on the second switch 155. Therefore, even if the second switch 155 is inadvertently turned on / off, the semiconductor switch 173 is kept on.

  As described above, in the present embodiment, in the first hammer mode, the first electrical switch 151 is mechanically fixed at the on position, and the second electrical switch 175 is turned on by operating the second switch 155 in this state. The controller 112 controls the energization of the drive motor 111 based on the / off signal. On the other hand, in the hammer drill mode or the second hammer mode, the second electrical switch 175 is electrically fixed at the ON position to invalidate the operation of the second switch 175, and in this state, the first electrical switch 151 by the first switch 153 is disabled. The power supply control of the drive motor 111 is performed by an on / off operation. With this configuration, the second switch 155 that operates the second electrical switch 175 can eliminate the need for mechanical connection with the mode switching dial 165. As a result, the switch structure for controlling the energization of the drive motor 111 requires fewer mechanical components, which simplifies the structure and improves the assemblability. Further, since the mechanical connecting structure is eliminated, the number of mechanical sliding portions is also reduced, which is effective in preventing malfunction caused by switch operation due to dust generated during hammering or hammer drilling.

  Further, according to the present embodiment, only one of the first switch 153 and the second switch 155 is selected when the first hammer mode is selected, and when either the hammer drill mode or the second hammer mode is selected. Since the energization control of the drive motor 111 can be performed simply by operating with a finger, the operability is improved. In addition, since the first switch 153 and the second switch 155 are arranged so as to face each other, an operation with one hand is possible and the operation is easy.

  In the present embodiment, the connecting rod 163 is disposed in the lower connecting region 109 a that connects the main body 103 and the handgrip 109 on the lower side of the handgrip 109, and the first handgrip 109 side on the handgrip 109 side is connected via the connecting rod 163. 1 switch 153 is connected to a switch lever 159 on the main body 103 side. Accordingly, the handgrip 109 having a vibration-proof structure, that is, the hand connected to the main body 103 so as to be relatively rotatable through the rotation shaft 183 in the lower connection region 109a and connected through the coil spring 185 in the upper connection region 109b. It can be applied to a hammer drill having a grip 109.

In the above-described embodiment, the first drive mode is described as having the hammer drill mode and the second hammer mode. However, the configuration further includes a drill mode in which the hammer bit 119 performs a drill operation only by the rotation operation. It does not matter. Further, in the present embodiment, the case where the crank mechanism is used as a mechanism for driving the striker 129 by converting the rotation output of the drive motor 111 into a linear motion has been described, but instead of the crank mechanism, for example, by the drive motor 111 A rotating plate (swash plate) is attached to a rotating shaft that is driven to rotate at a predetermined inclination angle with respect to the axis of the rotating shaft. Alternatively, a swing mechanism configured to perform a swing operation may be employed.
In the present embodiment, the second switch 155 is disposed at the rear end of the main body 103, but may be disposed in the upper connection region 109 b of the handgrip 109. The handgrip 109 may have a non-vibration-proof structure, that is, a structure in which the handgrip 109 is fixedly connected to the main body 109.

In view of the gist of the present invention, the following modes can be configured.
(Aspect 1)
“A striking tool according to claim 2 or 3,
A mode detection unit for detecting which side of the first drive mode and the second drive mode the mode switching member is;
When the detection signal of the first drive mode is input from the mode detection unit, the control unit disables the input signal input from the electric switch, thereby making the control by the input operation of the second switch operation member When energization control of the motor is prohibited and a detection signal of the second drive mode is input from the mode detection unit, the input signal input from the electric switch is validated, and the motor energization is performed based on the input signal. A striking tool configured to perform control. "
According to the first aspect of the invention, in the first drive mode, the energization control of the motor is performed in accordance with the turning-on operation of the first switch, and in the second driving mode, the turning-on operation of the second switch is performed. Accordingly, an impact tool capable of performing energization control on the motor is provided.

(Aspect 2)
"A striking tool according to any one of claims 1 to 6 or aspect 1,
The second switch operating member extends in a direction intersecting the long axis direction of the tool bit, and is rotatable at one end portion in the extending direction, and is always from the loading position side to the initial position side. A striking tool that is biased toward and held in the initial position. "
According to the second aspect of the invention, the second switch operation member can be turned on by a simple click operation such as pushing and releasing or pulling and releasing.

(Aspect 3)
"A striking tool according to claim 4 or 5,
The second switch operation member is disposed opposite to the first switch operation member disposed on the hand grip in a rear region of the main body portion to which the hand grip is connected. Blow tool to do. "
According to the third aspect of the invention, since the first switch operating member and the second switch operating member are arranged so as to face each other, it is possible to operate the switch operating member with one hand. Will improve.

It is sectional drawing which shows the whole structure of the electric hammer drill which concerns on this Embodiment. It is sectional drawing which shows the structure of the principal part of an electric hammer drill. It is sectional drawing which mainly shows the operation part of a drive motor, and shows the state in which the mode switching dial was put in the 1st hammer mode position. It is sectional drawing which mainly shows the operation part of a drive motor, and shows the state in which the mode switching dial was put in the hammer drill mode position or the 2nd hammer mode position. FIG. 4 is a cross-sectional view based on line XX in FIG. 3, showing a state in which the mode switching dial is placed at the first hammer mode position. It is sectional drawing based on the XX line of FIG. 3, and shows the state in which the mode switching dial was put in the hammer drill mode position or the 2nd hammer mode position. It is sectional drawing based on the YY line of FIG. It is a control circuit diagram of a drive motor.

Explanation of symbols

101 Electric hammer drill (blow tool)
103 Main body (tool body)
105 Motor housing 107 Gear housing 109 Hand grip 109a Lower joint area 111 Drive motor 112 Controller 113 Motion conversion mechanism 115 Impact element 117 Tool holder 119 Hammer bit (tool bit)
121 crankshaft 123 crank arm 125 piston 127 cylinder 129 striker 131 impact bolt 133 intermediate gear 135 intermediate shaft 137 first bevel gear 139 second bevel gear 141 power transmission mechanism 143 clutch member 151 first electric switch 151a operating projection 153 first switch (first switch 1 switch operation member)
154 Mounting shaft 155 Second switch (second switch operating member)
156 Spring (biasing member)
157 Mounting shaft 159 Switch lever 159a Upper end 161 Mounting shaft 163 Connecting rod 165 Mode switching dial (mode switching member)
166 Return spring 167 Slide plate 167a Opening 168 Slide guide 169 Plate cam 171 Drive circuit 172 Power supply 173 Semiconductor switch 175 Second electric switch 175a Operation protrusion 177 Third electric switch 177a Operation protrusion 178 Power supply section 179 Operation section 181 Operation status display section ( Display section)
183 Rotating shaft 185 Coil spring

Claims (6)

A motor that drives the tool bit linearly in the long axis direction;
First and second switch operating members for energizing and shutting off the motor;
A mode switching member that switches a mode between a first drive mode for arbitrarily driving the tool bit and a second drive mode for continuously driving the tool bit;
The first switch operating member is movable between a closing position where current is supplied to the motor and a non-closing position where the current is cut off, and is always from the closing position side to the non-closing position side. And when the mode switching member is placed on the first drive mode side, a throwing operation to the closing position by a finger is permitted, and the mode switching member is moved to the second driving mode side. When placed on the drive mode side, it is mechanically fixed in the loading position,
The second switch operating member can be turned on with a finger to control energization and shut-off of the motor, and the mode switching member is placed on either side of the first and second drive modes. However, when the making operation is permitted and the mode switching member is placed on the first drive mode side, the energization control of the motor by the making operation is not performed, and the mode switching member is When placed on the second drive mode side, the energization control of the motor by the closing operation is set to be performed,
In a state where the mode switching member is in the first drive mode, energization control of the motor is performed in accordance with a turning operation of the first switch operation member with a finger, and the mode switching member is in the second drive mode. A striking tool configured to perform energization control of the motor in accordance with a closing operation of the second switch operation member with a finger in the mode. The impact tool according to claim 1,
The second switch operating member can be moved between the initial position and the input position where the input operation has been performed, and is always urged from the input position side to the initial position side and placed at the initial position. With the configuration
An electrical switch that outputs a closing signal in conjunction with a closing operation of the second switch operating member to the closing position;
A control unit for energizing the motor in response to a closing signal input from the electrical switch,
The control unit is configured to perform energization control of the motor in accordance with the number of times of input signal input from the electric switch in a state where the mode switching member is placed in the second drive mode. An impact tool characterized by that. The impact tool according to claim 2,
The control unit has a reset function for erasing the history of turning on the electrical switch in the second drive mode and returning to the initial state when the power supply from the power supply unit connected to the control unit is cut off. Characteristic impact tool. The impact tool according to any one of claims 1 to 3,
A tool body;
A handgrip gripped by an operator connected to one end of the tool bit in the long axis direction of the tool body,
The handgrip is arranged so as to extend in a direction intersecting with the tool bit major axis direction, and one end side of the tool bit is extended with respect to the tool body via a rotation axis. The other end side in the extending direction is connected to the tool body via an elastic body,
The mode switching member is mounted on the tool body side,
The first switch operating member is configured by a trigger that is attached to the handgrip side, is moved to a closing position by a finger pulling operation, and is returned to a non-closing position when the pulling operation is released,
The trigger is connected to a linkage member extending to the tool body side through a connection portion between the tool body and the handgrip on one end side of the handgrip,
The linkage member moves the trigger to the closing position in conjunction with the movement operation of the mode switching member that is moved from the first driving mode side to the second driving mode side, and is fixed to the closing position. A striking tool characterized in that it is configured to perform. The impact tool according to claim 4,
The hand grip has an internal space in which the trigger can be stored,
The striking tool according to claim 1, wherein the trigger is housed in the internal space in a state of being fixed at the loading position. The impact tool according to any one of claims 1 to 5,
A striking tool comprising a display unit for displaying a driving state of the tool bit.

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