JP4243135B2 - Electric hammer drill - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
For example, the present invention switches between a hammer mode in which a work material (concrete) is shredded by a hammer bit striking operation and a hammer drill mode in which a drilling operation is performed by a combined operation of a hammer bit striking operation and a rotation operation. The present invention relates to an electric hammer drill capable of operating.
[0002]
[Prior art]
The electric hammer drill described above has a mode switching lever as a mode switching member, and by pulling the trigger provided on the handgrip with the mode switching lever while switching to the hammer mode or the hammer drill mode. The power switch of the drive motor is turned on (turned on) so that the chipping operation or the drilling operation can be selectively performed. Various techniques that enable such switching of work modes have been proposed in the past (see Patent Document 1).
[0003]
[Patent Document 1]
German Patent Application Publication No. 19720947
[0004]
[Problems to be solved by the invention]
When working with a hammer drill, it is preferable that the hammering operation in the hammer mode can be fixed (locked) at the 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 input operation / non-input operation without fixing the trigger at the input operation position because of 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 reliably and reliably perform the mode switching operation.
In view of the above, an object of the present invention is to provide an electric hammer drill that is effective for an operator to perform a mode switching operation reliably and reliably.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in each claim is configured.
According to invention of Claim 1, the electric hammer drill provided with the tool bit, the power switch, the trigger, the mode switching member, and the control member is comprised. The power switch turns on / off the motor. “On / off of energization” corresponds to a drive current supply and supply release operation to the motor. The trigger is operated by the operator to either the input state or the non-input 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 strikes, 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 between the first operating state, the second operating state, and the third operating state. By mode switching member It is configured to be alternatively switchable. In the first operating state, the trigger is allowed to be turned on and off, and Whether the trigger is in the on state or in the non-on state, The power switch is always turned on. In the second operating state, Engage with the trigger placed at the non-injection position to inhibit the trigger input operation. Prohibit power-on operation at all times Hold the power switch in the off state . As the “prohibited” form, for example, a form in which movement is mechanically restricted is suitable. 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 the presence or absence of the trigger operation. Set to the input state. That is, the power switch is turned on by switching the mode switching member to the hammer mode. For this reason, it is not necessary for the operator to hold the trigger at the loading position all the time, and it is possible to continuously perform a predetermined hammering operation with 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 in the second operating state, and the trigger operation and the power switch operation operation are always restricted. For this reason, in the neutral mode, even if the operator tries to turn on the trigger, it cannot be turned on, and the energization off state of the drive motor is held, so that the drive motor and the tool bit are held in a stopped state.
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. By doing so, 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 in which, for example, the drive motor continues to be driven when the hammer mode is directly switched to the drill mode or when the drill mode is switched 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 motor and perform a predetermined drill work or hammer drill work with the tool bit. Can be carried out at will.
[0009]
(Invention of Claim 2)
According to the invention described in claim 2, the trigger can be engaged or disengaged with respect to the control member. The control member is movable between a first position where the power switch is not turned on and a second position where the power switch is turned on. The mode switching member includes a switching operation unit that switches the 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 pressurize the control member and move the control member from the first position to the second position at the time of 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]
When the mode switching member is switched to the neutral mode, the second switching operation unit releases the pressure applied by the first switching operation unit and allows the control member to move from the second position to the first position. 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 bias the second position to the first position using, for example, a spring. This allows the control member to reasonably move from the second position to the first position when pressure is released. As the form of restraining the control member at the first position, typically, a form of locking (fixing) the control member using a mechanical lock mechanism is suitably employed.
[0012]
The third switching operation unit allows the control member to move to the third operating state by allowing the control member to move between the first position and the second position when the mode switching member is switched to the drill mode. It is assumed to be a composition.
[0013]
When switching the mode between hammer mode and drill mode, if the neutral mode is set in the middle of the switching operation area, the mode is switched directly between the hammer mode and drill mode. It is possible to effectively avoid unexpected troubles that may occur. 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 performed via the first switching operation unit, the second switching operation unit, and the third switching operation unit. Therefore, that is, the above-described problem avoidance can be achieved reasonably and reliably by adopting a configuration in which the mode is switched by a mechanical (mechanical) structure.
[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 that is 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 becomes possible to reduce the operation force at the time of the switching operation, compared with, for example, the linear movement switching type that is switched by linear movement.
[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 releases the pressurization include the control member The sliding member is slidably contacted and has a sliding surface having a height difference with respect to the moving direction of the control member, and the level difference parts of the sliding surface are connected by an inclined surface. For example, when the higher sliding surface comes into contact with the control member, the control member is pressurized to switch to the first operating state, and when the lower sliding surface comes into contact, the pressure is released. The control member can be switched to the second operating state or the third operating state. The inclined surface functions as a bridge when the control member moves between the high sliding surface and the low sliding surface, thereby facilitating the transfer of the control member between the high and low sliding surfaces. it can.
[0015]
DETAILED DESCRIPTION OF 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 overall configuration of an electric hammer drill (hereinafter simply referred to as a hammer drill) 101 according to the present embodiment. 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 distal end side (left end region in the figure) of the main body 103 of the hammer drill 101.
[0016]
A drive motor 121 is disposed 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. The Further, a tip tool mechanism 137 is arranged on the tip side (left end side in FIG. 1) of the striking force transmission mechanism 135 in the gear housing 107. The tip tool mechanism 137 is provided with a hammer bit mounting chuck 109 for detachably fastening the hammer bit 163. The hammer bit 163 corresponds to the “tool bit” in the present invention. Of 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 shown in FIG. Rather, the detailed structure is shown in FIGS.
[0017]
On the other hand, the hammer bit 163 extends from the gear housing 107 into the tip tool mechanism 137 with respect to the tool holder 161 arranged to extend in the long axis direction (left and right direction in FIG. 1) of the hammer bit 163. A relative reciprocation in the long axis direction is possible, and the relative rotation in the circumferential direction is held in a restricted state.
The drive motor 121 in the motor housing 105 is energized and driven by turning on (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 and off the drive motor 121 is attached to the handgrip 111 so as to be pivotable about the pivot center 113a. The trigger 113 is turned on and off, or is controlled through a switch control mechanism 350 that operates in conjunction with the mode switching operation of the mode switching mechanism 330. This will be described in detail later.
[0018]
As shown in FIGS. 1 and 2 to 4, the first power transmission mechanism 131 in the gear housing 107 rotates with the first gear 145 and the first gear 145 that mesh with and engage with the output shaft 123. The driven shaft 147, a connecting rod 148 having one end connected to a position deviated from the rotation center of the first driven shaft 147 by a predetermined distance, and a driver 153 attached to the other end of the connecting rod 148 are mainly configured. Has been.
[0019]
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 rotational torque transmission gear 181 fixed to the second driven shaft 179, a rotational torque transmission gear 162 meshing with the rotational torque transmission gear 181, a clutch mechanism 201 for transmitting or shutting off the power of the rotational torque transmission gear 162 to the tool holder 161, A torque transmission pin 183 that transmits rotation of the tool holder 161 to the hammer bit 163 and a torque transmission groove 165 into which the torque transmission pin 183 is fitted are mainly configured. That is, the tool holder 161 can rotate when the clutch mechanism 201 is connected, and cannot rotate when the clutch mechanism 201 is disconnected.
[0020]
The clutch mechanism 201 is mainly composed of 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 always rotated when the drive motor 121 is driven.
On the other hand, the driven clutch body 213 is slidably disposed in the axial direction at a position adjacent to the drive clutch body 211. When the driven clutch body 213 is slid in the direction close to 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 via the engagement of the claws, and the drive clutch body 211 When it is slid away from the drive clutch body 211, the drive clutch body 211 is disconnected. The driven clutch body 213 is mechanically coupled to the tool holder 161 so that power can be mechanically transmitted in a state in which relative sliding in the axial direction is allowed, for example, by a spline structure.
[0021]
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 is fitted in a torque transmission groove 165 formed in a cutout shape on the peripheral surface of the hammer bit 163. The torque transmission groove 165 is formed in an elongated shape in the long axis direction of the hammer bit 163, and the torque of the torque transmission pin 183 is also applied when the hammer bit 163 moves linearly relative to the tool holder 161. The fitting to the transmission groove 165 is maintained.
[0022]
The air cylinder mechanism 133 includes a cylinder 151 that slidably accommodates the driver element 153 and the striker 155 in the bore, and an air chamber that is defined between the driver element 153 and the striker 155 in the bore of the cylinder 151. 157 is the main constituent.
[0023]
The striking force transmission mechanism 135 is mainly composed of an impact bolt 159 that receives a strike of the striker 155 that linearly moves at high speed via the air cylinder mechanism 133 and moves linearly. The impact bolt 159 is configured as a rod-shaped member having a long axis in the linear motion direction (left and right direction in FIG. 1), and its outer peripheral surface is in sliding contact with the inner peripheral surface of the tool holder 161 so as to be reciprocally movable.
[0024]
The mode switching mechanism 330 includes a mode switching lever 331 for mode switching operation that switches modes according to work modes, a pinion 333 that connects or disconnects the clutch mechanism 201 in conjunction with the mode switching operation of the mode switching lever 331, and a link arm. 339 is mainly configured. The mode switching lever 331 corresponds to a “mode switching member” in the present invention.
The mode switching lever 331 is disposed in the gear housing 107 and at a position closer to the upper outer side of the cylinder 151. Then, one end is attached to the case cover 108, which is a fixed member, so as to be rotatable in the horizontal direction (direction perpendicular to the paper surface in FIGS. It is possible to selectively switch between a neutral mode, a hammer mode for performing a chipping 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, the neutral mode position (see FIG. 5B) is set at the center position in the switching operation region of the mode switching lever 331, and the hammer mode position (see FIG. 5B) is sandwiched between the neutral mode positions. 5 (A)), and a hammer drill mode position (see FIG. 5 (C)) is set on the other side.
[0025]
Further, the mode switching lever 331 extends substantially horizontally toward the handgrip 111 side, and an operation knob 331 b is formed on the distal end side which is the extended end portion, and the operation knob 331 b is formed on the gear housing 107. It protrudes outward. That is, the mode switching lever 331 can be switched between modes on the outside of the gear housing 107 using the operation knob 331b.
[0026]
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 the clutch mechanism 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. The pinion 333 is formed with an eccentric pin 333a at a position eccentric from the rotation center 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 like the mode switching lever 331, and is formed with a bifurcated engagement claw 339a at the other end, and the engagement claw 339a is formed with a driven clutch body 213. The flange portion 213a is engaged so as to be sandwiched from both sides in the moving direction, and is slidable in the circumferential direction.
[0027]
Therefore, when the mode switching lever 331 is switched to the hammer mode, the driven clutch body 213 is moved away from the driving clutch body 211 via the rack 335, the pinion 333, the eccentric pin 333a, and the link arm 339, and the clutch is moved. When disconnected and switched to the hammer drill mode, the driven clutch body 213 is moved in the direction approaching the drive clutch 211 to connect the clutch.
[0028]
The switch control mechanism 350 mainly includes a control arm 351 for controlling the power switch 115 for turning on / off the energization of the drive motor 121 and the trigger 113 operated by the operator to either the on state or the non-on state. Configured as The power switch 115 corresponds to the “power switch” in the present invention. The trigger 113 corresponds to the “trigger” in the present invention. The control arm 351 corresponds to a “control member” in the present invention.
[0029]
The control arm 351 is disposed between the power switch 115 and the trigger 113, and is a position where the power switch 115 is not turned on, that is, a non-turned position (position shown in FIGS. 5B and 5C). It can be moved between a position to be put in, that is, a pouring position (position shown in FIG. 5A). The non-insertion position corresponds to the “first position” in the present invention, and the input position corresponds to the “second position” in the present invention.
The control arm 351 has a switch control unit 351a that contacts the actuator 115a of the power switch 115 at one end, and a hook-shaped engagement unit 351b that engages with the trigger 113 in a detachable manner at the other end. ing. The engaging portion 351b of the control arm 351 is configured to engage with the trigger 113 in the non-on state when the power switch 115 is in the non-on state (off state).
[0030]
The mode switching lever 331 is formed with an arm switching operation unit 337 that slidably contacts the switch control unit 351a of the control arm 351 at a predetermined distance from the pin 331a serving as a rotation fulcrum. The arm switching operation unit 337 pressurizes the switch control unit 351a when the mode switching lever 331 is switched to the hammer mode, thereby allowing the trigger 113 to be turned on and off, and the trigger 113 to be operated. A pressurizing unit 337a that turns on the power switch 115 regardless of the presence or absence, and a pressurization releasing unit 337b that releases the above pressurization when the mode switching lever 331 is switched to the neutral mode or the hammer drill mode. Have. The pressurizing unit 337a and the pressurizing release unit 337b are slidably in contact with the control arm 351, and are configured by sliding surfaces having a height difference with respect to the moving direction of the control arm 351. And the height difference part of the sliding surface is set as the structure connected by the inclined surface 337c.
[0031]
The arm switching operation portion 337 of the mode switching lever 331 has a movement restricting projection 337d that engages with the switch control portion 351a of the control arm 351 when the mode switching lever 331 is switched to the neutral mode. The movement restricting projection 337d is configured to restrict the movement of the control arm 351 by engaging with the switch control unit 351a, thereby prohibiting the turning operation of the power switch 115 and the turning operation of the trigger 113 at all times.
The arm switching operation unit 337 corresponds to the “switching operation unit” in the present invention. Further, the pressurizing unit 337a corresponds to the “first switching operation unit” in the present invention, and the combination of the pressure release unit 337b and the movement restricting projection 337d is the “second switching operation unit” in the present invention. Correspondingly, the single pressure release unit 337b corresponds to the “third switching operation unit” in the present invention.
[0032]
The hammer drill 101 according to the present embodiment is configured as described above. Next, the operation and usage method of the hammer drill 101 will be described.
When the hammer drill 101 is not used, the mode switching lever 331 is switched to the neutral mode, which is the center position of the mode switching operation area, as shown in FIG. In this 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 pressurization. For this reason, the control arm 351 is moved to the non-on position by the spring action of the power switch 115 in the non-on position, and the power switch 115 is also held in the non-on state. Therefore, the drive motor 115 and the hammer bit 119 are stopped. On the other hand, the movement restricting protrusion 337d of the arm switching operation unit 337 engages with the switch control unit 351a of the control arm 351, and restrains the control arm 351 from moving in the direction in which the power switch 115 is turned on. Thereby, the turning-on operation of the power switch 115 and the turning-on operation of the trigger 113 by the operator are prohibited. Therefore, even if the operator holds the handgrip 111 and tries to turn on the trigger 113, the turning-on operation of the trigger 113 is restricted and the non-loading position is surely held, which contributes to the improvement of safety. The operating state of the control arm 351 in the neutral mode corresponds to the “second operating state” in the present invention.
[0033]
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 portion 351a of the control arm 351 is released as shown in FIG. In addition, the pressurizing unit 337a pressurizes the switch control unit 351a. As a result, the control arm 351 moves and turns on the power switch 115. For this reason, the drive motor 121 is energized and the rotational output of the drive motor 121 is transmitted to the gear 145 via the output shaft 123, whereby the first driven shaft 147 is rotationally driven together with the gear 145. The rotation of the first driven shaft 147 causes one end of the connecting rod 148 to revolve around the first driven shaft 147, and the driver 153 attached to the other end of the connecting rod 148 in a loose-fitting manner reciprocates within the bore of the cylinder 151. Perform a linear motion.
[0034]
Along with the linear motion of the driver 153, the striker 155 linearly moves toward the impact bolt 159 at a speed higher than the speed of the linear motion 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 moves linearly toward the hammer bit 163 at a 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 a high speed. That is, the hammer bit 163 performs a hammering operation to perform hammering work such as chipping.
[0035]
On the other hand, with respect to the second power transmission mechanism 139, the rotational output of the drive motor 121 is transmitted to the second gear 171 via the output shaft 123, and from the second gear 171 to the second driven shaft 179, the rotational torque transmission gear 181 and the rotation. The drive clutch body 211 is rotated through 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. It is cut. For this reason, rotation of the drive clutch body 211 is not transmitted to the hammer bit 163, and so-called drilling is not performed.
[0036]
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 hammering operation only by the hammering operation of the hammer bit 163 on the workpiece without operating the trigger 113. That is, the hammering operation can be performed with the energization of the drive motor 121 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 operation of turning on and off the trigger 113 is allowed, but the operation is an empty operation without any effect. Therefore, it is possible to perform a predetermined hammering operation by firmly grasping the grip hand 111 without being particular about the operation of turning on and off the trigger 113. The operating state of the control arm 351 in the hammer mode corresponds to the “first operating state” in the present invention.
[0037]
Further, when the mode switching lever 331 is switched from the neutral mode to the hammer drill mode by the operator, the pressure release unit 337b of the arm switching operation unit 337 is connected to the control arm 351 as shown in FIG. The state facing the switch control unit 351a is continued, and the engagement of the movement restricting protrusion 337d with the switch control unit 351a is released. As a result, the trigger 113 is turned on and off by the operator.
[0038]
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 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, so that 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 (striking operation) of the drill bit 163 and the drill operation (rotation operation). If the trigger 113 is turned off, the power switch 115 is switched to the non-turned-on state, and the drive motor 121 is stopped. The operating state of the control arm 351 in the hammer drill mode corresponds to the “third operating state” in the present invention.
[0039]
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 worker can continuously perform the hammer work by the hammer bit 163, and at this time, it is not necessary to continuously perform the input operation of the trigger 113, so that the burden on the worker is reduced.
On the other hand, in the hammer drill mode, the drive motor 115 is driven or stopped by turning the trigger 113 on and off. For this reason, the operator can perform the hammer drill work continuously or intermittently by appropriately turning on and off the trigger 113.
Further, in the neutral mode, the operation of 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, an inadvertent hammering operation or drilling operation of the hammer bit 163 is prevented, and the operator can use it with peace of mind.
[0040]
Further, in the present embodiment, a configuration is adopted in which an 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 passes through the neutral mode, and in the case of switching directly 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 from hammer mode to hammer drill mode directly, the hammer bit is subjected to a rotational load on the work piece in addition to the hammering operation, and the work that grips the hammer drill accordingly. There is a possibility that a rotational moment as a reaction force of the rotational load acts on a person's hand. Further, if the hammer drill mode is directly switched to the hammer mode, a hammer bit striking operation is continuously performed. According to the present embodiment, by interposing the neutral mode between the hammer mode and the hammer drill mode, it is possible to eliminate work troubles caused by the above phenomenon.
[0041]
Further, in the present embodiment, the step between the sliding surface of the pressurizing unit 337a and the sliding surface of the pressurizing release unit 337b formed in the arm switching operation unit 337 is connected by the inclined surface 337c. The switching operation between the pressure unit 337a and the pressure release unit 337b is smoothly realized.
[0042]
The mode switching lever 331 is configured to be switched by a turning operation around a predetermined turning center. According to such a rotation switching method, an operation force having a magnitude proportional to the distance between the rotation center and the operation part is set by setting the operation knob 331b at a position spaced a predetermined distance from the rotation center. Can be obtained. For this reason, 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 in the case where the switching operation is performed by linear movement, for example. Can do. Further, by adopting a configuration in which the operation knob 331b is disposed in a 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 surface or the like, It is possible to prevent the operation knob 331b from directly touching the floor surface and avoid unexpected switching of the mode switching lever 331.
[0043]
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 hammering work, it is possible to perform hammering work continuously without increasing the number of parts, compared to the conventional case where a part for pulling the trigger and locking the operation position is required. The advantage that it can be obtained.
[0044]
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 movement method instead of the rotation method using the pin 331a as a fulcrum. Good.
Further, in the present embodiment, a mode is selected between a hammer mode in which the hammer bit 119 performs a batting 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 batting operation and a rotation operation. However, the hammer drill mode may be changed to a drill mode in which the hammer bit 119 performs only the rotation operation.
[0045]
【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 reliably performed with peace of mind.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an overall configuration of an electric hammer drill according to an embodiment.
FIG. 2 is a cross-sectional view showing the main part of the electric hammer drill according to the present embodiment, showing the hammer mode.
FIG. 3 is also a cross-sectional view showing the main part of the electric hammer drill, showing the neutral mode.
FIG. 4 is also a cross-sectional view showing the main part of the electric hammer drill, showing the hammer drill mode.
5A and 5B are explanatory diagrams showing mode switching modes, in which FIG. 5A shows the hammer mode, FIG. 5B shows the neutral mode, and FIG. 5C shows the hammer drill mode.
[Explanation of symbols]
101 Electric hammer drill
103 Main 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 Rotational torque transmission gear
163 Hammerbit
165 Torque transmission groove
171 Second gear
179 Second driven shaft
181 Rotational torque transmission gear
201 Clutch mechanism
211 Drive clutch body
213 Driven clutch body
211a Driving claw
213a Driven claw
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 racks
337 Arm switching actuator
337a Pressure unit
337b Pressure release part
337c inclined surface
337d Movement restriction protrusion
339 Link Arm
339a engaging claw
350 Switch control mechanism
351 Control arm
351a Switch control unit
351b Engagement part

Claims (4)

A tool bit;
A power switch for turning on / off the energization of a motor for driving the tool bit;
A trigger that is manipulated by the operator into either the on or off state;
A mode switching member capable of switching between a hammer mode in which the tool bit strikes, a neutral mode in which the tool bit stops, and a drill mode in which the tool bit at least rotates; and
It is arranged between the power switch and the trigger, allows the trigger to be turned on and off, and in either state where the trigger is in the on state or in the non-on state the a first operating condition to constantly on state power switch, engages with the trigger placed in off position prohibits the closing operation of the trigger, thereby turning on the power switch by the trigger A second operation state in which the operation is always prohibited and the power switch is not turned on, and a third operation state in which the power switch is turned on or off in conjunction with a trigger operation by an operator And an electric hammer drill having a control member that can be selectively switched by the mode switching member between ,
The control member is
In the hammer mode, the first operating state is set.
In the neutral mode, the second operating state is set.
The drill mode is configured to be in the third operating state,
The electric hammer drill, wherein the neutral mode is set at an intermediate position between the hammer mode and the drill mode. The electric hammer drill according to claim 1,
The trigger can be engaged with or disengaged from the control member,
The control member is movable between a first position where the power switch is not turned on and a second position where 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 part is
When the mode switching member is switched to the hammer mode, the control member is pressurized and moved from the first position to the second position to bring the control member into the first operating state. When,
When the mode switching member is switched to the neutral mode, the pressure applied 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 places the control member in the second operation state by restraining the control member moved to the position to the first position;
When the mode switching member is switched to the drill mode, the control member is allowed to move between the first position and the second position, thereby bringing the control member into the third operating state. An electric hammer drill comprising a switching operation portion. The electric hammer drill according to claim 1 or 2,
The electric hammer drill is characterized in that 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 pressurizes the control member and the second switching operation unit that releases the pressurization are slidably in contact with the control member and are related to the movement direction of the control member. An electric hammer drill comprising a sliding surface having a height difference, wherein the height difference portions of the sliding surface are connected by an inclined surface.

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