JP2004330379A - Electric hammer drill - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric hammer drill effective for surely performing switching operations of modes at ease by a worker. <P>SOLUTION: This drill is provided with a power source switch 121, a trigger switch 113 operated to either one of turning and non-turning states, a mode switching lever 331 capable of switching and operating among a hammer mode, a neutral mode and a drill mode, and a switch control arm 351 arranged between the power source switch 121 and the trigger switch 113. A switch control member is switched to a first operating state for allowing the turning and non-turning operations of the trigger switch 113 in the hammer mode and always making the power source switch 121 into the turning state, regardless of the presence or absence of the operation of the trigger switch 113, is switched to a second operating state for always inhibiting the turning operation of the trigger switch 113 and the turning operation of the power source switch 121 in the neutral mode, and is switched to a third operating state for making the power source switch 121 into the turning state or the non-turning state by interlocking with the trigger switch operation in the drill mode. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention switches between, for example, a hammer mode in which a workpiece (concrete) is cut by a hammer bit hitting operation and a hammer drill mode in which a boring operation is performed by a combined operation of a hammer bit hitting operation and a rotating operation. Capable electric hammer drill.
[0002]
[Prior art]
The above-described electric hammer drill has a mode switching lever as a mode switching member. By switching the mode to the hammer mode or the hammer drill mode by pulling a trigger provided on the hand grip by the mode switching lever. The power switch of the drive motor is turned on (turned on) so that a filing operation or a drilling operation can be selectively performed. Conventionally, various technologies that enable the switching of the work mode have been proposed (see Patent Document 1).
[0003]
[Patent Document 1]
DE 197 20 947 A1
[0004]
[Problems to be solved by the invention]
When working using a hammer drill, in the hammering mode, it is preferable that the trigger can be fixed (locked) to a closing operation position where the power switch is turned on from the viewpoint of reducing the burden on the operator. In the drilling operation in the mode, it is preferable that the operator can freely perform the closing operation and the non-closing operation without fixing the trigger at the closing operation position due to the nature of the operation. On the other hand, when the mode is switched by the mode switching lever, it is necessary for the operator to be able to perform the mode switching operation reliably and securely.
An object of the present invention is to provide an electric hammer drill that is effective from the above-described viewpoints for an operator to perform a mode switching operation with security and reliability.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in each claim is configured.
According to the first aspect of the present invention, an electric hammer drill including a tool bit, a power switch, a trigger, a mode switching member, and a control member is configured. The power switch turns on / off the energization of the motor. “On / off of energization” corresponds to supply and release operations of the drive current to the motor. The trigger is operated by a worker in one of a closed state and a non-closed state. The mode switching member is provided so that the operator can perform a switching operation between a hammer mode in which the tool bit hits, a neutral mode in which the tool bit stops, and a drill mode in which the tool bit rotates at least.
The control member is disposed between the power switch and the trigger, and is configured to be selectively switchable between a first operating state, a second operating state, and a third operating state. In the first operating state, the operation of turning on and off the trigger is permitted, and the power switch is always turned on regardless of whether the trigger is operated. In the second operating state, the operation of turning on the trigger and the operation of turning on the power switch are always prohibited. As a form of “prohibition”, for example, a form in which movement is mechanically controlled is preferable. In the third operating state, the power switch is turned on or off in conjunction with the trigger operation by the operator.
[0006]
According to the first aspect of the present invention, when the hammer mode is selected via the mode switching member, the control member is set to the first operating state, whereby the power switch is always turned on regardless of whether or not the trigger is operated. It is in the closed state. That is, the ON state of the power switch is maintained by the switching operation of the mode switching member to the hammer mode. Therefore, it is not necessary for the operator to always hold the trigger at the closing position, and the operator can continuously perform the predetermined hammer operation using the tool bit, thereby reducing the burden on the operator.
[0007]
On the other hand, when the neutral mode is selected via the mode switching member, the control member is set to the second operating state, and the operation of turning on the trigger and the operation of turning on the power switch are always regulated. For this reason, in the neutral mode, even if the operator tries to turn on the trigger, the trigger cannot be turned on and the power supply to the drive motor is kept off, so that the drive motor and the tool bit are kept stopped.
The neutral mode is preferably set in the middle of the switching operation area when switching from the hammer mode to the drill mode or when switching from the drill mode to the hammer mode. In this way, when switching from the hammer mode to the drill mode or from the drill mode to the hammer mode, the drive motor can be temporarily stopped. For this reason, it is possible to avoid a phenomenon that the drive motor continues to be driven when the mode is directly switched from the hammer mode to the drill mode or from the drill mode to the hammer mode.
[0008]
Further, when the drill mode is selected via the mode switching member, the control member is set to the third operating state, and the power switch is turned on or off in conjunction with the trigger operation. That is, in this drill mode, the operator switches the power switch freely to the ON state or the non-ON state by a trigger operation to turn on / off the energization of the motor, and performs a predetermined drilling operation or a hammer drilling operation by the tool bit. It can be performed arbitrarily with will.
[0009]
(Invention of claim 2)
According to the second aspect of the present invention, the trigger can be engaged with or released from the control member. The control member is movable between a first position where the power switch is turned off and a second position where the power switch is turned on. The mode switching member includes a switching operation unit that switches an operation state of the control member, and the switching operation unit includes a first switching operation unit, a second switching operation unit, and a third switching operation unit. .
[0010]
The first switching operation unit is configured to press the control member and move the control member from the first position to the second position when switching to the hammer mode, thereby bringing the control member into the first operation state. . As a form for pressurizing the control member, for example, a form mechanically linked to the switching operation of the mode switching member, or a form electrically linked to the switching operation of the mode switching member using a solenoid or the like can be adopted. is there.
[0011]
The second switching operation unit releases the pressurization by the first switching operation unit and allows the control member to move from the second position to the first position when the mode switching member switches to the neutral mode. At the same time, the control member moved to the first position is constrained to the first position so that the control member is brought into the second operating state. The control member is configured to urge from the second position to the first position using, for example, a spring. Thereby, when the pressurization is released, the control member is allowed to rationally move from the second position to the first position. As a form for restricting the control member to the first position, typically, a form in which the control member is locked (fixed) using a mechanical lock mechanism is suitably adopted.
[0012]
The third switching operation unit allows the control member to move between the first position and the second position when the mode switching member switches to the drill mode, thereby causing the control member to move to the third operation state. And the configuration.
[0013]
When the mode is switched between the hammer mode and the drill mode, if the neutral mode is set in the middle of the switching operation area, the mode is directly switched between the hammer mode and the drill mode. Possible unexpected problems can be effectively avoided. According to the second aspect of the present invention, when the mode switching member is switched, the movement or restraint of the control member is mechanically controlled via the first switching operation unit, the second switching operation unit, and the third switching operation unit. , Ie, the mode is switched by a mechanical (mechanical) structure, so that the above-described problem avoidance can be achieved rationally and reliably.
[0014]
(Invention of claim 3)
According to the third aspect of the present invention, in the electric hammer drill according to the second aspect, the mode switching of the mode switching member is performed by a rotation operation around a predetermined rotation center. According to such a rotation switching method, by setting the operation unit at a position at a predetermined distance from the rotation center, an operation force having a magnitude proportional to the distance between the rotation center and the operation part is obtained. Obtainable. For this reason, it is possible to reduce the operation force at the time of the switching operation, for example, as compared with a linear movement switching type that switches by moving linearly.
[0015]
(Invention of claim 4)
According to a fourth aspect of the present invention, in the electric hammer drill according to the second or third aspect, the first switching operation unit that pressurizes the control member and the second switching operation unit that cancels the pressurization include the control member. , And a sliding surface having a height difference with respect to the moving direction of the control member, and a step portion of the sliding surface is connected by an inclined surface. The control member is pressed to switch to the first operating state by, for example, contacting the higher sliding surface with the higher sliding surface, and the pressure is released by contacting the lower sliding surface with the lower sliding surface. The control member can be switched to a second operating state or a third operating state. The inclined surface acts as a bridge when the control member moves between the high and low sliding surfaces, thereby facilitating the transition of the control member between the high and low sliding surfaces. it can.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an electric hammer drill according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows an entire configuration of an electric hammer drill (hereinafter, simply referred to as a hammer drill) 101 according to the present embodiment. The outer periphery of the hammer drill 101 according to the present embodiment is generally formed by a main body 103 having a motor housing 105, a gear housing 107, and a hand grip 111. A hammer bit 163 is attached to the tip side (left end area in the drawing) of the main body 103 of the hammer drill 101.
[0017]
A drive motor 121 is arranged in the motor housing 105. In the gear housing 107, a first power transmission mechanism 131, an air cylinder mechanism 133, a striking force transmission mechanism 135, a second power transmission mechanism 139, a clutch mechanism 201, a mode switching mechanism 330, and a switch control mechanism 350 are arranged. You. In the gear housing 107, a tip tool mechanism 137 is disposed on the tip side (left end side in FIG. 1) of the striking force transmission mechanism 135. A hammer bit mounting chuck 109 for detachably fixing the hammer bit 163 is disposed on the tip tool mechanism 137. The hammer bit 163 corresponds to a “tool bit” in the present invention. Note that, among the mechanisms in the motor housing 105, the first power transmission mechanism 131, the air cylinder mechanism 133, the second power transmission mechanism 139, the clutch mechanism 201, the mode switching mechanism 330, and the switch control mechanism 350 are only those in FIG. 2 to 4 show the detailed structure.
[0018]
On the other hand, the hammer bit 163 is moved from the inside of the gear housing 107 to the inside of the tip tool mechanism 137 with respect to the tool holder 161 that is arranged to extend in the long axis direction (the horizontal direction in FIG. 1) of the hammer bit 163. It is held in a state where relative reciprocation in the long axis direction is possible and relative rotation in the circumferential direction is restricted.
The drive motor 121 in the motor housing 105 is energized and driven by turning on the power switch 115, and the rotational force of the drive motor 121 is output to the output shaft 123. As shown in detail in FIG. 2, the turning on and off of the power switch 115 for turning on / off the energization of the drive motor 121 is performed by turning the power switch 115 on the hand grip 111 so as to be rotatable around the rotation center 113a. It is configured to be controlled via a switch control mechanism 350 that operates in conjunction with the input and non-input operations of the triggered trigger 113 or the mode switching operation of the mode switching mechanism 330. This will be described in detail later.
[0019]
As shown in FIG. 1 and FIGS. 2 to 4, the first power transmission mechanism 131 in the gear housing 107 includes a first gear 145 that meshes and engages with the output shaft 123, and a first gear 145 that rotates together with the first gear 145. The driven shaft 147, a connecting rod 148 having one end connected to a position eccentric from the rotation center of the first driven shaft 147 by a predetermined distance, and a driver 153 attached to the other end side of the connecting rod 148 are mainly constituted. Have been.
[0020]
On the other hand, as shown in FIGS. 1 and 2, the second power transmission mechanism 139 in the gear housing 107 includes a second gear 171 that meshes with the output shaft 123, and a second driven shaft to which the second gear 171 is fixed. 179, a rotating torque transmitting gear 181 fixed to the second driven shaft 179, a rotating torque transmitting gear 162 meshing with the rotating torque transmitting gear 181, a clutch mechanism 201 for transmitting or cutting off the power of the rotating torque transmitting gear 162 to the tool holder 161; A torque transmission pin 183 for transmitting the rotation of the tool holder 161 to the hammer bit 163 and a torque transmission groove 165 in which the torque transmission pin 183 fits are mainly configured. In other words, the tool holder 161 can rotate when the clutch mechanism 201 is connected, and cannot rotate when the clutch mechanism 201 is disconnected.
[0021]
The clutch mechanism 201 mainly includes a drive clutch body 211 and a driven clutch body 213. The drive clutch body 211 is integrally provided with a rotational torque transmission gear 162, and is constantly rotated when the drive motor 121 is driven.
On the other hand, the driven clutch 213 is disposed at a position adjacent to the drive clutch 211 so as to be slidable in the axial direction. When the driven clutch body 213 is slid in a direction approaching the drive clutch body 211 by a mode switching mechanism 330 described later, the driven clutch body 213 is connected to the drive clutch body 211 through the engagement of the pawl, and Is disengaged from the drive clutch body 211 when it is slid away from the drive clutch body 211. The driven clutch body 213 is mechanically connected to the tool holder 161 in a state where relative sliding in the axial direction is permitted by, for example, a spline structure.
[0022]
A torque transmission pin 183 is disposed at an appropriate position of the tool holder 161 in the tip tool mechanism 137. The torque transmission pin 183 fits into a torque transmission groove 165 formed in a notch on the peripheral surface of the hammer bit 163. The torque transmission groove 165 is formed in a long shape in the longitudinal direction of the hammer bit 163. Even when the hammer bit 163 linearly moves relative to the tool holder 161 to perform a hammer operation, the torque of the torque transmission pin 183 can be increased. The engagement with the transmission groove 165 is maintained.
[0023]
The air cylinder mechanism 133 includes a cylinder 151 that slidably accommodates the driver 153 and the striker 155 in the bore, and an air chamber defined between the driver 153 and the striker 155 in the bore of the cylinder 151. 157 as a main component.
[0024]
The striking force transmitting mechanism 135 mainly includes an impact bolt 159 that linearly moves in response to the striking of the striker 155 that moves linearly at a high speed via the air cylinder mechanism 133. The impact bolt 159 is configured as a rod-shaped member having a long axis in the direction of the linear movement (the left-right direction in FIG. 1), and its outer peripheral surface is in sliding contact with the inner peripheral surface of the tool holder 161 in a reciprocating manner.
[0025]
The mode switching mechanism 330 includes a mode switching lever 331 for mode switching operation for switching modes according to a work mode, a pinion 333 for connecting or disconnecting the clutch mechanism 201 in conjunction with a mode switching operation of the mode switching lever 331, and a link arm. 339 as a main component. The mode switching lever 331 corresponds to the “mode switching member” in the present invention.
The mode switching lever 331 is disposed inside the gear housing 107 and at a position closer to the upper outside of the cylinder 151. Then, one end is attached to the case cover 108 as a fixing member so as to be rotatable in a horizontal direction (a direction orthogonal to the paper surface in FIGS. 1 to 4) with the pin 331 a as a fulcrum. , A neutral mode, a hammer mode for performing a filing operation, and a hammer drill mode for performing a drilling operation. The hammer drill mode corresponds to the “drill mode” in the present invention. In the present embodiment, a neutral mode position (see FIG. 5B) is set at the center position in the switching operation region of the mode switching lever 331, and one of the hammer mode positions (see FIG. 5 (A)), and a hammer drill mode position (see FIG. 5 (C)) is set on the other side.
[0026]
The mode switching lever 331 extends substantially horizontally toward the handgrip 111, and an operation knob 331 b is formed on the extending end portion of the mode switching lever 331. The operation knob 331 b is connected to the gear housing 107. It protrudes outward. In other words, the mode switching operation of the mode switching lever 331 can be performed using the operation knob 331b outside the gear housing 107.
[0027]
When the mode switching lever 331 is switched, the switching operation is transmitted from the arc-shaped rack 335 formed on the mode switching lever 331 to the clutch mechanism 201 via the pinion 333 and the link arm 339, and 201 is connected and disconnected. That is, the pinion 333 is rotatably attached to the case cover 108 and always meshes with the rack 335. An eccentric pin 333a is formed on the pinion 333 at a position eccentric from the center of rotation by a predetermined distance, and the eccentric pin 333a is rotatably connected to one end of the link arm 339. The link arm 339 extends substantially horizontally in the same manner as the mode switching lever 331, and has a bifurcated engagement claw 339 a formed at the other end thereof, and the engagement claw 339 a is formed on the driven clutch body 213 by a ring. It is engaged with the flange portion 213a so as to sandwich it from both sides in the moving direction, and is slidable in the circumferential direction.
[0028]
Therefore, when the mode switching lever 331 is switched to the hammer mode, the driven clutch 213 is moved away from the drive clutch 211 via the rack 335, the pinion 333, the eccentric pin 333a, and the link arm 339, and the clutch is disengaged. When the operation is switched to the hammer drill mode, the driven clutch body 213 is moved in the direction approaching the drive clutch 211 and the clutch is connected.
[0029]
The switch control mechanism 350 mainly includes a power switch 115 for turning on / off the energization of the drive motor 121 and a control arm 351 for controlling the trigger 113 which is operated by the operator in a closed state or a non-closed state. It is constituted as. The power switch 115 corresponds to a “power switch” in the present invention. The trigger 113 corresponds to “trigger” in the present invention. The control arm 351 corresponds to the “control member” in the present invention.
[0030]
The control arm 351 is disposed between the power switch 115 and the trigger 113, and sets the power switch 115 in a non-switching state, that is, a non-switching position (positions illustrated in FIGS. 5B and 5C). It is possible to move between a position to be set in an input state, that is, an input position (a position shown in FIG. 5A). The non-loading position corresponds to the “first position” in the present invention, and the charging position corresponds to the “second position” in the present invention.
The control arm 351 has, at one end, a switch control section 351a that contacts the operator 115a of the power switch 115, and at the other end, a hook-shaped engagement section 351b that detachably engages the trigger 113. ing. The engaging portion 351b of the control arm 351 is configured to engage with the trigger 113 in the non-switched-on state when the power switch 115 is not switched on (off-state).
[0031]
The mode switching lever 331 is provided with an arm switching operation section 337 that is slidably abutted on the switch control section 351a of the control arm 351 at a position at a predetermined distance from the pin 331a as a rotation fulcrum. When the mode switching lever 331 is switched to the hammer mode, the arm switching operating unit 337 presses the switch control unit 351a to allow the trigger 113 to be turned on and off, and to allow the trigger 113 to be operated. A pressurizing section 337a that turns on the power switch 115 regardless of the presence or absence, and a pressurizing release section 337b that releases the pressurization when the mode switching lever 331 is switched to the neutral mode or the hammer drill mode. Have. The pressurizing section 337a and the pressurizing release section 337b are slidably in contact with the control arm 351, and are configured by a sliding surface having a height difference with respect to the moving direction of the control arm 351. Then, a configuration is adopted in which the height difference portion of the sliding surface is connected by an inclined surface 337c.
[0032]
Further, the arm switching operation section 337 of the mode switching lever 331 has a movement restricting projection 337d that engages with the switch control section 351a of the control arm 351 when switching to the neutral mode. The movement restricting protrusion 337d restricts the movement of the control arm 351 by engaging with the switch control unit 351a, thereby always prohibiting the turning-on operation of the power switch 115 and the turning-on operation of the trigger 113.
The arm switching operation section 337 corresponds to the “switching operation section” in the present invention. In addition, the pressing portion 337a corresponds to the “first switching operation portion” in the present invention, and the combination of the pressure release portion 337b and the movement restricting protrusion 337d corresponds to the “second switching operation portion” in the present invention. Correspondingly, the single pressure release section 337b corresponds to the “third switching operation section” in the present invention.
[0033]
The hammer drill 101 according to the present embodiment is configured as described above. Next, the operation and usage of the hammer drill 101 will be described.
When the hammer drill 101 is not used, as shown in FIG. 5B, the mode switching lever 331 has been switched to the neutral mode, which is the center position of the mode switching operation area. In the neutral mode, the pressure release unit 337b of the arm switching operation unit 337 faces the arm control unit 351a of the control arm 351, and releases the pressure. Therefore, the control arm 351 has been moved to the non-switching position by the spring action in the non-switching position direction held by the power switch 115, and the power switch 115 is also held in the non-switching state. Therefore, the drive motor 115 and the hammer bit 119 are stopped. On the other hand, the movement restricting projection 337d of the arm switching operation part 337 is engaged with the switch control part 351a of the control arm 351 to restrict the control arm 351 from moving in the direction of turning on the power switch 115. As a result, the operation of turning on the power switch 115 and the operation of turning on the trigger 113 by the operator are prohibited. Therefore, even if the operator grips the handgrip 111 and tries to turn on the trigger 113, the turning-on operation of the trigger 113 is restricted, and the trigger 113 is securely held at the non-shot position, which contributes to improvement of safety. The operation state of the control arm 351 in the neutral mode described above corresponds to the “second operation state” of the present invention.
[0034]
When the mode switching lever 331 is switched from the neutral mode to the hammer mode by the operator, the engagement of the movement restricting protrusion 337d with the switch control unit 351a of the control arm 351 is released as shown in FIG. At the same time, the pressing unit 337a presses the switch control unit 351a. As a result, the control arm 351 moves to turn on the power switch 115. Therefore, the drive motor 121 is energized and the rotation output of the drive motor 121 is transmitted to the gear 145 via the output shaft 123, whereby the first driven shaft 147 is driven to rotate together with the gear 145. One end of the connecting rod 148 revolves around the first driven shaft 147 due to the rotation of the first driven shaft 147, and the driver 153, which is loosely fitted to the other end of the connecting rod 148, reciprocates in the bore of the cylinder 151. Perform a linear motion.
[0035]
With the linear movement of the driver 153, the striker 155 linearly moves toward the impact bolt 159 at a speed higher than the linear movement of the driver 153 by the action of a so-called air spring. When the striker 155 collides with the impact bolt 159, the kinetic energy of the striker 155 is transmitted to the impact bolt 159, and the impact bolt 159 linearly moves toward the hammer bit 163 at high speed. When the impact bolt 159 collides with the hammer bit 163, the kinetic energy of the impact bolt 159 is transmitted to the hammer bit 163, and the hammer bit 163 linearly moves forward at high speed. That is, when the hammer bit 163 performs a hammering operation, a hammering operation such as fraying is performed.
[0036]
On the other hand, as for the second power transmission mechanism 139, the rotation output of the drive motor 121 is transmitted to the second gear 171 via the output shaft 123, and the second driven shaft 179, the rotation torque transmission gear 181 and the rotation are transmitted from the second gear 171 to the second gear 171. The drive clutch body 211 is rotated via the torque transmission gear 162. At this time, when the mode switching lever 331 is switched to the hammer mode, the driven clutch body 213 is separated from the drive clutch body 211 via the rack 335, the pinion 333, and the link arm 339 as shown in FIG. Has been cut. Therefore, the rotation of the drive clutch body 211 is not transmitted to the hammer bit 163, and the so-called drilling operation is not performed.
[0037]
That is, when the mode switching lever 331 is switched to the hammer mode, the power switch 115 is turned on by the switching operation, and the on state is continued. For this reason, the operator can perform a predetermined hammer operation on the workpiece by only hitting the hammer bit 163 without operating the trigger 113. That is, the hammer work can be performed in a state where the energization of the drive motor 121 is always locked on. In the hammer mode, the engaging portion 351b of the control arm 351 is disconnected from the trigger 113. For this reason, the closing operation and the non-closing operation of the trigger 113 are allowed, but the operation is an idle operation without effect. Therefore, it is possible to perform a predetermined hammer operation by firmly grasping the grip hand 111 without being particular about the operation of turning on and off the trigger 113. The operation state of the control arm 351 in the above-described hammer mode corresponds to the “first operation state” of the present invention.
[0038]
Further, when the mode switching lever 331 is switched from the neutral mode to the hammer drill mode by the operator, as shown in FIG. 5C, the pressure release unit 337b of the arm switching operating unit 337 controls the control arm 351. The state facing the switch control unit 351a is continued, and the engagement of the movement restriction protrusion 337d with the switch control unit 351a is released. Thereby, the operation of turning on and off the trigger 113 by the operator is allowed.
[0039]
If the trigger 113 is turned on in this state, the power switch 115 is turned on via the control arm 351 and the drive motor 121 is energized. Therefore, as in the case of the hammer mode, the driving force of the drive motor 121 is transmitted to the hammer bit 163, and the hammer bit 163 performs a hammer operation. On the other hand, in the hammer drill mode, the driven clutch body 213 is pulled toward the drive clutch body 211 via the rack 335, the pinion 333, and the link arm 339 by the switching operation of the mode switching lever 331, and the clutch is connected. Is transmitted to the hammer bit 163. As a result, in the hammer drill mode, a predetermined hammer drill operation is performed on the workpiece by a combined operation of the hammer operation (hitting operation) of the drill bit 163 and the drill operation (rotation operation). When the trigger 113 is turned off, the power switch 115 is switched to the non-turn-on state, and the drive motor 121 is stopped. The operation state of the control arm 351 in the above-mentioned hammer drill mode corresponds to the "third operation state" of the present invention.
[0040]
As described above, according to the present embodiment, in the hammer mode, the power switch 115 is turned on by the switching operation of the mode switching lever 331, and the drive motor 115 is energized. For this reason, the operator can continuously perform the hammering operation by the hammer bit 163, and at this time, there is no need to continuously perform the triggering operation of the trigger 113, so that the burden on the operator is reduced.
On the other hand, in the hammer drill mode, the drive motor 115 is driven or stopped by making and not making an operation of the trigger 113. For this reason, the operator can perform the hammer drilling operation continuously or intermittently by operating the trigger 113 as appropriate, with or without the operation.
Further, in the neutral mode, the operation of turning on the power switch 115 and the operation of turning on the trigger 113 are prohibited by restricting the movement of the control arm 351. For this reason, when the neutral mode is selected, careless hammering or drilling of the hammer bit 163 is prevented, and the operator can use the machine with peace of mind.
[0041]
Further, in the present embodiment, a configuration is adopted in which the intermediate position of the switching operation area of the mode switching lever 331 that is rotated for mode switching is set to the neutral mode position. For this reason, the switching to the hammer mode or the hammer drill mode always goes through the neutral mode, and in the case of directly switching from the hammer mode to the hammer drill mode or from the hammer drill mode to the hammer mode, for example, the drive motor 121 Can be avoided. For example, when switching directly from the hammer mode to the hammer drill mode, in addition to hitting the hammer bit, a rotating load acts on the workpiece due to the drilling operation, and the work that holds the hammer drill accordingly There is a possibility that a phenomenon occurs in which a rotational moment as a reaction force of the rotational load acts on the hand of the user. If the mode is directly switched from the hammer drill mode to the hammer mode, a phenomenon occurs in which the hammering bit is continuously operated. According to the present embodiment, by interposing the neutral mode between the hammer mode and the hammer drill mode, it is possible to obviate the trouble in work caused by the above-mentioned phenomenon.
[0042]
Further, in the present embodiment, a step between the sliding surface of the pressing portion 337a and the sliding surface of the pressure releasing portion 337b formed on the arm switching operation portion 337 is connected by the inclined surface 337c. The switching operation between the pressing unit 337a and the pressure releasing unit 337b is smoothly realized.
[0043]
The mode switching lever 331 is configured to be switched by a rotation operation around a predetermined rotation center. According to such a rotation switching method, by setting the operation knob 331b at a position at a predetermined distance from the rotation center, the operation force having a magnitude proportional to the distance between the rotation center and the operation part is obtained. Can be obtained. Therefore, by increasing the distance from the center of the pin 331a, which is the rotation fulcrum, to the operation knob 331b (input point), the switching operation can be performed more easily than when the switching operation is performed by, for example, linear movement. Can be. Furthermore, by adopting a configuration in which the operation knob 331b is disposed in the space S formed between the hand grip 111 and the gear housing 107 or the motor housing 105, for example, when the hammer drill 101 is placed on the floor or the like, By preventing the operation knob 331b from directly touching the floor surface, it is possible to avoid unexpected switching of the mode switching lever 331.
[0044]
Further, in the present embodiment, when the mode switching lever 331 is switched to the hammer mode, the power switch 115 of the drive motor 121 is automatically switched to the ON state. For this reason, in order to continuously perform hammer work, it is necessary to perform a continuous hammer work without increasing the number of parts, as compared with the related art, which requires a component for pulling a trigger and locking the operation position. The advantage that it can be obtained is obtained.
[0045]
Note that the present invention is not limited to the above-described embodiment. For example, the switching operation of the mode switching lever 331 may be a linear moving method instead of a rotating method using the pin 331a as a fulcrum. Good.
In the present embodiment, the mode is a hammer mode in which the hammer bit 119 performs a hitting operation, a neutral mode in which the operation of the hammer bit 119 is stopped, and a hammer drill mode in which the hammer bit 119 performs a hitting operation and a rotating operation. However, the hammer drill mode may be changed to the drill mode in which the hammer bit 119 performs only the rotation operation.
[0046]
【The invention's effect】
As described above in detail, according to the present invention, in the electric hammer drill, the mode switching operation can be performed reliably and securely.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating an entire configuration of an electric hammer drill according to the present embodiment.
FIG. 2 is a cross-sectional view showing a main part of the electric hammer drill according to the embodiment, showing a hammer mode.
FIG. 3 is a cross-sectional view showing a main part of the electric hammer drill in a neutral mode.
FIG. 4 is a cross-sectional view showing a main part of the electric hammer drill in a hammer drill mode.
5A and 5B are explanatory diagrams showing a mode switching mode, wherein FIG. 5A shows a hammer mode, FIG. 5B shows a neutral mode, and FIG. 5C shows a hammer drill mode.
[Explanation of symbols]
101 Electric hammer drill
103 body
105 Motor housing
107 gear housing
108 Case cover
109 Hammer bit mounting housing
111 hand grip
113 Trigger
115 Power switch
121 drive motor
123 output shaft
131 1st power transmission mechanism
133 Air cylinder mechanism
135 Impact force transmission mechanism
137 Tip tool mechanism
139 Second power transmission mechanism
145 First gear
147 First driven shaft
148 connecting rod
151 cylinder
153 driver
161 Tool holder
161a Spline groove
162 rotating torque transmission gear
163 hammer bit
165 Torque transmission groove
171 Second gear
179 Second driven shaft
181 Rotary torque transmission gear
201 Clutch mechanism
211 Drive clutch body
213 Driven clutch body
211a drive claw
213a driven nail
213b Power transmission claw
213c Flange
330 mode switching mechanism
331 Mode switching lever
331a pin
331b Operation knob
333 pinion
333a Eccentric pin
335 rack
337 Arm switching operation part
337a Pressurizing section
337b Pressure release section
337c slope
337d Movement control protrusion
339 link arm
339a engaging claw
350 Switch control mechanism
351 control arm
351a switch control unit
351b engaging part

Claims (4)

Tool bits,
A power switch for turning on / off the energization of a motor that drives the tool bit,
A trigger operated by the operator in one of a closing state and a non-closing state;
A mode switching member that can be switched between a hammer mode in which the tool bit performs a hitting operation, a neutral mode in which the tool bit stops, and a drill mode in which the tool bit rotates at least.
A first operating state in which the power switch is arranged between the power switch and the trigger to allow a trigger to be turned on and off, and to always turn on the power switch regardless of whether the trigger is operated; A second operation state in which a trigger operation and a power switch operation are always prohibited, and a third operation state in which the power switch is turned on or off in response to a trigger operation by an operator. An electric hammer drill having a control member that can be selectively switched between
The control member,
In the hammer mode, the first operation state is set,
In the neutral mode, the second operating state is set,
In the drill mode, the electric hammer drill is set to the third operation state. The electric hammer drill according to claim 1,
The trigger can be engaged or disengaged with the control member,
The control member is movable between a first position in which the power switch is turned off and a second position in which the power switch is turned on,
The mode switching member has a switching operation unit that switches an operation state of the control member,
The switching operation unit,
A first switching operation unit that, when switching the mode switching member to the hammer mode, pressurizes the control member and moves the control member from the first position to the second position to bring the control member into the first operation state; When,
When the mode switching member is switched to the neutral mode, the pressurization by the first switching operation unit is released to allow the control member to move from the second position to the first position, and A second switching operation unit that brings the control member into a second operation state by constraining the control member moved to the position to the first position;
A third operation in which the control member is brought into a third operating state by allowing the control member to move between a first position and a second position when the mode switching member is switched to the drill mode. An electric hammer drill comprising a switching operation part. The electric hammer drill according to claim 1 or 2,
An electric hammer drill, wherein the mode switching of the mode switching member is performed by a rotation operation around a predetermined rotation center. The electric hammer drill according to claim 2 or 3,
The first switching operation unit that presses the control member and the second switching operation unit that releases the press contact the control member in a slidable manner and with respect to a moving direction of the control member. An electric hammer drill comprising a sliding surface having a height difference, wherein a height difference portion of the sliding surface is connected by an inclined surface.

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