JP4509894B2 - Impact type work tool - Google Patents

Description

  The present invention relates to a technique for alleviating a reaction force received from a workpiece during a hammer operation in an impact-type work tool that performs a linear hammer operation on the workpiece.

  Japanese Patent Application Laid-Open No. 8-318342 (Patent Document 1) discloses a technique for alleviating the impact force caused by the bounce of a bit after a hitting operation in a hammer drill. In the hammer drill described in Patent Document 1, a rubber ring (buffer member) is interposed between an axial end surface of a cylinder, which is a main body side member, and an impact bolt as an intermediate that strikes the bit. And after a bit hit | damage operation | movement, when a bit rebounds with the reaction force received from the said workpiece and an impact bolt collides with a rubber ring, the said rubber ring will bend, and the impact force will be relieved. On the other hand, the rubber ring also functions as a positioning member for the hammer drill body with respect to the workpiece during hammering. That is, during the biting operation of the bit, the user maintains the state where the tip of the bit is pressed against the workpiece by applying a forward pressing force to the hammer drill body (holding the bit at the hitting position) In this configuration, the cylinder as the main body side receives the pressing force of the bit at this time via the rubber ring.

As described above, the conventional rubber ring has both the function of reducing the impact force caused by the bounce of the bit and the positioning function of the hammer drill during the hammering operation. The rubber ring should be soft to buffer the bounce of the bit. On the other hand, the rubber ring should be hard to improve the positioning of the hammer drill. In other words, in the conventional rubber ring structure, different properties are required for the rubber ring, and there is still room for improvement in that it is difficult to set the hardness to satisfy both functions.
JP-A-8-318342

  In view of this point, an object of the present invention is to provide a technique that contributes to a reduction in impact force due to rebounding of a bit after an impact operation in an impact work tool.

In order to achieve the above object, the invention described in each claim is configured.
According to the first aspect of the present invention, the tool main body and the hammer actuating member which is disposed in the tip region of the tool main body and performs a predetermined hammering operation on the workpiece by linearly moving in the long axis direction. And an impact type work tool having a drive mechanism for driving the hammer actuating member linearly through an air spring. The “predetermined hammer work” in the present invention includes not only a hammer work in which the hammer actuating member performs only a linear striking operation, but also a hammer drill work in which a straight striking operation and a circumferential rotation operation are performed. . The “hammer actuating member” in the present invention typically corresponds to a tool bit and an impact bolt that transmits a striking force in contact with the tool bit. In the present invention, “the hammer actuating member is linearly driven via the air spring” typically means a pressure fluctuation in the cylinder bore space (air chamber) due to relative movement of the piston and the cylinder, specifically, A mode in which the hammer actuating member is driven linearly by hitting the hammer actuating member by the striking element driven by the elastic action of the air generated by compressing the air in the cylinder bore space corresponds to this.

The impact type work tool of the present invention is built in the tool main body so as to be movable in the longitudinal direction of the hammer operating member , and the hammer operating member receives a reaction from the work material when the hammer operation is performed on the work material. For the force, the hammer actuating member is placed in direct contact with the hammer actuating member or in the reaction force transmission position where it is placed in contact with the hammer actuating member via a hard metal inclusion. The weight includes a weight to which the reaction force from the weight is transmitted, and an absorbing means for absorbing the reaction force transmitted to the weight. Note that the “weight” in the present invention is typically formed by a cylindrical member, but includes an aspect in which the weight is constituted by a plurality of members separated from each other in the circumferential direction. The “absorbing means” is typically an elastic element such as a spring or rubber that is elastically deformed by being pushed by a weight that moves backward due to the transmitted reaction force, thereby absorbing the reaction force. Applicable, but preferably includes an absorption mechanism using a damping mechanism or frictional resistance.

  During the hammering operation, the hammer actuating member bounces upon receiving a reaction force from the workpiece after the striking operation. According to the present invention, with respect to the reaction force received by the hammer operating member from the workpiece, the weight is placed in direct contact with the hammer operating member, or is contacted via a hard metal inclusion. The reaction force is transmitted from the hammer operating member to the weight at the reaction force transmission position where the reaction force is placed, and the reaction force is transmitted almost 100%. In other words, the reaction force is transmitted in a form in which the momentum is exchanged between the hammer actuating member and the weight. The transmission of the reaction force causes the weight to move backward in the direction in which the reaction force acts. The reaction force transmitted to the weight is absorbed by the absorbing means. That is, according to the present invention, the impact force (reaction force) caused by the rebound generated in the hammer operating member is absorbed by the rearward movement of the weight, the elastic deformation of the elastic element due to the movement of the weight, the damping action of the damping mechanism, and the like. As a result, the vibration of the impact-type work tool can be reduced.

  The impact type work tool of the present invention includes an air spring operating member that can be switched between a non-operating position that disables the air spring and an operating position that enables the air spring, and the air spring operating member is in a non-operating position. And an urging member that urges the operating member to the non-operating position. Here, the “non-operating position in which the air spring is disabled” typically means that the air chamber is communicated to the outside to disable the operation of the air spring by the relative operation of the piston and the cylinder, thereby causing the drive mechanism to This corresponds to the position where the operation of the hammer operating member is disabled. The “operating position where the air spring is effective” means that the air spring can be operated by the relative movement of the piston and the cylinder by blocking the communication with the outside of the air chamber. This is the position at which operation is possible. Therefore, according to the present invention, in a state where the air spring operating member is placed at the non-operating position, the driving of the hammer operating member by the driving mechanism is disabled. That is, it is possible to prevent the hammer operating member from being idle. On the other hand, when the air spring actuating member is switched from the non-actuated position to the actuated position, the hammer actuating member can be driven by the drive mechanism, and the hammer operation on the workpiece can be performed by the hammer actuating member. Note that the switching operation of the air spring operating member from the non-operating position to the operating position is typically performed by a backward movement operation of the hammer operating member when the hammer operating member is pressed against the workpiece. Not limited to.

(Invention of Claim 2)
According to the second aspect of the present invention, the tool main body and the hammer actuating member which is disposed in the tip region of the tool main body and performs a predetermined hammering operation on the workpiece by linearly moving in the long axis direction. And a drive mechanism that drives the hammer actuating member linearly via an air spring, and a reaction force that the hammer actuating member receives from the workpiece when the hammer act on the workpiece directly with the hammer actuating member. The reaction force from the hammer actuating member is transmitted at the reaction force transmission position where it is placed in contact with the hammer actuating member or in contact with the hammer actuating member via the hard metal inclusion. A weight, an absorbing means for absorbing a reaction force transmitted to the weight, an air spring operating member that can be switched between a non-operating position that disables the air spring and an operating position that enables the air spring, and an air spring Operation A biasing member for biasing the actuating member to the non-actuated position so that the material is placed in the non-actuated position; and a hammer actuating member interposed between the hammer actuating member and the tool body in a resilient manner. The weight and elastic member are arranged in parallel in the radial direction at the same position on the long axis of the hammer actuating member, and the hammer actuating member is pressed against the workpiece during the hammering operation. The force acting on the hammer operating member is received by the tool body through an elastic member. As the “elastic member” in the present invention, a rubber ring-shaped member, that is, a rubber ring is typically suitable, but a spring can be applied.

According to the present invention, when a user performs a hammer operation by applying a forward pressing force to the tool body to press the tip of the hammer operating member against the workpiece, the reaction of the pushing force acting on the hammer operating member is counteracted. A force (force opposite to the pressing force of the tool body) is received by the tool body via an elastic member, and thereby the tool body is positioned with respect to the workpiece. According to the present invention, most of the reaction force received by the hammer operating member from the workpiece after the striking operation is transmitted from the hammer operating member to the weight as described in the first aspect of the invention. Is placed almost stationary as viewed from the striking position. That is, since the movement of the hammer actuating member to the rear is suppressed, the reaction force from the hammer actuating member acting on the elastic member is small. For this reason, the amount of elastic deformation of the elastic member due to the reaction force becomes extremely small, and the subsequent repulsive force is also reduced. Further, the impact force caused by the bounce of the hammer actuating member can be absorbed by the weight and the elastic element. As a result, the elastic member is made hard, and the tool body is properly positioned with respect to the workpiece through the elastic member. Can be achieved.

(Invention of Claim 3)
According to the third aspect of the present invention, the tool main body and the hammer actuating member which is disposed in the tip region of the tool main body and performs a predetermined hammering operation on the workpiece by linearly moving in the long axis direction. A drive mechanism that linearly drives the hammer actuating member via an air spring, a cylinder that is fixedly attached to the tool body, and that is arranged so that the drive element of the drive mechanism can linearly move in the long axis direction, and a hammer When the actuating member performs hammering on the workpiece, the reaction force received from the workpiece is placed in direct contact with the hammer actuating member or via a hard metal inclusion. At a reaction force transmission position that is placed in contact with the operating member, a weight to which the reaction force from the hammer operating member is transmitted, an absorbing means for absorbing the reaction force transmitted to the weight, and an air spring Invalid An air spring actuating member that is switchable between a non-actuating position and an actuating position that activates the air spring, and a bias that biases the actuating member to the inoperative position so that the air spring actuating member is placed in the inoperative position The air spring actuating member is configured by a sleeve that is movably disposed on the outer periphery of the cylinder.

(Invention of Claim 4 )
According to the invention of claim 4, Te impact power tool smell of claim 1 or 3, interposed between the wafer comma actuating member and the tool body, a hammer actuating member to the tool body Tamahatsujo It is set as the structure which has an elastic member connected to. Also during hammering operation, and configured to receive by the hammer actuating member constantly via the elastic member the tool body forces that acting on the time of pressing the hammer actuating member to the workpiece. As the “elastic member” in the present invention, a rubber ring-shaped member, that is, a rubber ring is typically suitable, but a spring can be applied.

  According to the present invention, when a user performs a hammer operation by applying a forward pressing force to the tool body to press the tip of the hammer operating member against the workpiece, the reaction of the pushing force acting on the hammer operating member is counteracted. A force (force opposite to the pressing force of the tool body) is received by the tool body via an elastic member, and thereby the tool body is positioned with respect to the workpiece. According to the present invention, most of the reaction force received by the hammer operating member from the workpiece after the striking operation is transmitted from the hammer operating member to the weight as described in the first aspect of the invention. Is placed almost stationary as viewed from the striking position. That is, since the movement of the hammer actuating member to the rear is suppressed, the reaction force from the hammer actuating member acting on the elastic member is small. For this reason, the amount of elastic deformation of the elastic member due to the reaction force becomes extremely small, and the subsequent repulsive force is also reduced. Further, the impact force caused by the bounce of the hammer actuating member can be absorbed by the weight and the elastic element. As a result, the elastic member is made hard, and the tool body is properly positioned with respect to the workpiece through the elastic member. Can be achieved.

(Invention of Claim 5 )
According to the fifth aspect of the present invention, the hammer operating member in the impact type work tool according to any one of the first to fourth aspects includes an impact bolt that receives a driving force from the drive mechanism, and the impact bolt collides. And a tool bit that moves linearly. The impact bolt is configured to transmit the reaction force from the workpiece to the weight through a contact state with the weight. According to the present invention, the reaction force transmitted from the workpiece to the impact bolt through the tool bit can be transmitted to the weight in a concentrated manner without branching from the middle of the transmission path. The transmission efficiency is high, and as a result, the shock absorbing function can be enhanced.

(Invention of Claim 6 )
According to the sixth aspect of the present invention, the hammer operating member in the impact type work tool according to any one of the first to fourth aspects includes an impact bolt that receives a driving force from the drive mechanism, and the impact bolt collides. And a tool bit that moves linearly. The tool bit is configured to transmit the reaction force from the workpiece to the weight through a contact state with the weight. According to the present invention, because the reaction force from the workpiece is transmitted from the tool bit to the weight, a wide space for placing the weight is secured behind the tool bit arranged in the tip region of the tool body. This increases the degree of freedom in designing the weight weight or axial length.

(Invention of Claim 7 )
According to the invention described in claim 7 , the air spring operating member in the impact type work tool according to any one of claims 1 to 6 presses the hammer operating member against the workpiece during the hammering operation. At this time, the hammer is moved directly from the non-operating position to the operating position by the hammer operating member that is pressed by the workpiece and moved backward. The impact type work tool of the present invention performs a hammer operation in a state where the hammer operating member is pressed against the workpiece. Therefore, according to the present invention, the air spring actuating member is actuated from the non-actuated position using the backward movement of the hammer actuating member when the hammer actuating member is pressed against the workpiece to perform the hammering operation. Because of the configuration of moving to the position, it is not necessary to bother operating the air spring operating member when performing the hammering operation, and the air spring operating member can be rationally operated.

(Invention of Claim 8 )
According to the invention described in claim 8 , in the impact type work tool according to any one of claims 1 to 7 , the inclusion interposed between the hammer actuating member and the weight is attached to the tool body. Thus, the hammer actuating member is mounted so as not to move in the major axis direction. The inclusion interposed between the hammer operating member and the weight is a reaction force transmitting member that transmits a reaction force received by the hammer operating member from the workpiece to the weight. Therefore, the reaction force transmission position can be made steady by adopting a configuration in which the inclusion does not move in the major axis direction of the hammer actuating member, that is, the reaction force transmission direction. For this reason, it is possible to improve the transmission of the reaction force by ensuring the contact state of the hammer operating member and the weight with respect to the inclusion.

  According to the present invention, in the impact-type work tool, a technique that contributes to a reduction in impact force due to rebounding of the bit after the hitting operation is provided.

(First embodiment of the present invention)
Hereinafter, the first embodiment of the present invention will be described in detail with reference to FIGS. This embodiment will be described using an electric hammer drill as an example of an impact work tool. FIG. 1 is a side sectional view showing the entire configuration of the electric hammer drill according to the present embodiment, and shows a load when a hammer bit is pressed against a workpiece. As shown in FIG. 1, the hammer drill 101 according to the present embodiment generally includes a main body 103 that forms an outline of the hammer drill 101, and a tool holder 137 in a tip region (left side in the drawing) of the main body 103. The main body is composed of a hammer bit 119 that is detachably attached via a pin and a hand grip 109 that is gripped by an operator connected to the opposite side of the hammer bit 119 of the main body 103. The main body 103 corresponds to the “tool main body” in the present invention. The hammer bit 119 is held by the tool holder 137 so that the hammer bit 119 can be reciprocated relatively in the major axis direction, and the relative rotation in the circumferential direction is restricted. The hammer bit 119 corresponds to a “tool bit” in the present invention. 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 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 117. The rotational 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 the major axis direction of the hammer bit 119 (the left-right direction in FIG. 1) via the striking element 115. Generates an impact force on. The rotational output of the drive motor 111 is appropriately decelerated by the power transmission mechanism 117 and then transmitted 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, and a lower end side thereof is connected to a lower end of the rear end of the motor housing 105 via a rotation shaft 109a so as to be rotatable in the front-rear direction, and an upper end side is for vibration absorption. Is connected to the upper rear end of the motor housing 105 through an elastic spring 109b. Thereby, transmission of vibration from the main body 103 to the hand grip 109 is reduced.

  FIG. 2 is a sectional view showing an enlarged state of the main part of the hammer drill 101. The motion conversion mechanism 113 includes a drive gear 121 that is rotationally driven in the horizontal plane by the drive motor 111, a driven gear 123 that meshes and engages with the drive gear 121, and a crank plate that rotates in the horizontal plane integrally with the driven gear 123. 125, a crank arm 127 whose one end is connected in a loosely-fitted manner via an eccentric shaft 126 at a position eccentric from the center of rotation of the crank plate 125, and a connecting shaft 128 connected to the other end of the crank arm 127. The main component is a piston 129 as a driving element attached via the. The motion conversion mechanism corresponds to the “drive mechanism” in the present invention. The crank plate 125, the crank arm 127, and the piston 129 constitute a crank mechanism.

  On the other hand, the power transmission mechanism 117 includes a drive gear 121 driven by a drive motor 111, a transmission gear 131 meshingly engaged with the drive gear 121, a transmission shaft 133 rotated in a horizontal plane together with the transmission gear 131, and the transmission A small bevel gear 134 provided on the shaft 133, a large bevel gear 135 that meshes with and engages with the small bevel gear 134, and a tool holder 137 that rotates together with the large bevel gear 135 in a vertical plane are mainly configured. The hammer drill 101 applies a striking force in the long axis direction to the hammer bit 119 so as to perform the work of the workpiece, so-called hammering work, a striking force in the long axis direction, and a rotational force in the circumferential direction. In addition, a so-called hammer drilling operation is performed so as to perform the processing operation of the workpiece by appropriately switching, but since this is not directly related to the present invention, the description thereof will be given. Omitted. The illustration of the workpiece is omitted for convenience.

  The striking element 115 is mainly composed of a striker 143 as a striking element slidably disposed on the bore inner wall of the cylinder 141 together with the piston 129. The cylinder 141 is fixedly attached to the gear housing 107. The striker 143 is driven via an air spring of the air chamber 141a of the cylinder 141 accompanying the sliding movement of the piston 129, and collides (hits) an impact bolt 145 as an intermediate element slidably disposed on the tool holder 137. The impact force is transmitted to the hammer bit 119 via the impact bolt 145. The impact bolt 145 and the hammer bit 119 correspond to a “hammer actuating member” in the present invention. The impact bolt 145 has a predetermined large space in the axial direction between the large diameter portion 145a closely fitted to the inner peripheral surface of the cylindrical hole of the tool holder 137 and the inner peripheral surface of the cylindrical hole of the tool holder 137. A stepped structure including a medium diameter portion 145e and a small diameter portion 145b is formed. The impact bolt 145 has taper portions 145c and 145f in the boundary region between the large diameter portion 145a and the medium diameter portion 145 and the boundary region between the medium diameter portion 145e and the small diameter portion 145b, respectively, and the large diameter portion 145a. Is arranged in the tool holder 137 so that the small diameter portion 145b is the rear side.

  The hammer drill 101 is an impact bolt 145 that is pushed rearward (piston 129 side) together with the hammer bit 119 in a loaded state in which the user applies a forward pressing force to the main body 103 to press the hammer bit 119 against the workpiece. Is provided with a positioning member 151 for positioning the main body 103 with respect to the workpiece. The positioning member 151 includes a rubber rubber ring 153 formed in a ring shape, a hard front metal washer 155 bonded to the front side in the axial direction of the rubber ring 153, and a rear side in the axial direction of the rubber ring 153. This is a unit part composed of the hard rear washer 157, and is disposed on the outer peripheral surface of the medium diameter part 145e and the small diameter part 145b of the impact bolt 145 on the long axis of the hammer bit.

  The rear washer 157 of the positioning member 151 includes a cylindrical portion 157a extending in a predetermined length in the hammer bit major axis direction, and an inner flange portion 157b projecting in the inner diameter direction at the front end of the cylindrical portion. The rear washer 157 further has a stepped inner diameter portion at the rear end of the cylindrical portion 157 a, and the stepped inner diameter portion is fitted to the front end outer periphery of the cylinder 141. On the other hand, the front surface of the front metal washer 155 is in contact with the inner diameter step portion 137 a of the tool holder 137 via the spacer 159. Thus, the positioning member 151 is mounted between the cylinder 141 and the tool holder 137 in a state where the movement of the hammer bit 119 in the long axis direction is prohibited. For this reason, when the impact bolt 145 is not pushed rearward and no load is applied, the front metal washer 155 of the positioning member 151 is held at a position away from the impact bolt 145 as shown in FIG.

  When the impact bolt 145 is pushed backward, as shown in FIGS. 1 and 2, the positioning member 151 has a taper portion 145c between the large diameter portion 145a and the medium diameter portion 145e of the impact bolt 145, that is, a taper on the front side. The portion 145 c is in contact with the tapered inner diameter portion of the front metal washer 155 of the positioning member 151, and the rear washer 157 is in contact with the front end portion of the cylinder 141. Thereby, the rubber ring 153 of the positioning member 151 connects the impact bolt 145 to the cylinder 141 in a resilient manner. The rubber ring 153 corresponds to an “elastic member” in the present invention.

  The hammer drill 101 according to the present embodiment includes an impact damper 161 that reduces an impact force (reaction force) due to the bounce of the hammer bit 119 after the striking operation during a hammering operation on a workpiece. The impact damper 161 has a cylindrical weight 163 made of hard metal that comes into contact with the impact bolt 145 via the front metal washer 155 in the longitudinal direction of the hammer bit, and the cylindrical weight 163 is always on the impact bolt 145 side (front). And a coil spring 165 as an elastic element for urging the spring. The cylindrical weight 163 corresponds to the “weight” in the present invention, the coil spring 165 corresponds to the “absorbing means” in the present invention, and the front metal washer 155 corresponds to the “inclusion” in the present invention.

  The cylindrical weight 163 is disposed in a space between the outer peripheral surface of the positioning member 151 and the inner peripheral surface of the tool hole 137 and is movable in the long axis direction of the hammer bit. The movement is guided by the peripheral surface. That is, the cylindrical weight 163 is configured to be arranged in parallel in the radial direction at the same position on the long axis of the hammer bit 119 with respect to the positioning member 151. The cylindrical weight 163 extends further rearward from the outer peripheral region of the positioning member 151 and reaches the outer peripheral front region of the cylinder 141, and a coil spring 165 is interposed between the rear end portion and the tool holder 137. The coil spring 165 is elastically interposed in a state where a predetermined initial load is applied between the cylindrical weight 163 and the tool holder 137. Thus, the cylindrical weight 163 is biased forward, and the front end in the axial direction is always in contact with the outer peripheral side rear surface of the front metal washer 155 in the positioning member 151 in a surface contact state. The forward biasing force of the cylindrical weight 163 by the coil spring 165 is received by the front metal washer 155 contacting the inner diameter step portion 137a in the cylindrical hole of the tool holder 137 via the spacer 159. Thus, the movement of the cylindrical weight 163 is stopped so as not to move forward beyond the striking position. The striking position is a position where the striker 143 collides (hits) with the impact bolt 145, and this position is also a position where the reaction force from the impact bolt 145 is transmitted to the cylindrical weight 163. This position corresponds to the “reaction force transmission position” in the present invention.

  The cylindrical weight 163 is placed in contact with the impact bolt 145 via the front metal washer 155 of the positioning member 151 when the impact bolt 145 is pushed rearward together with the hammer bit 119. As a result, when the hammer bit 119 and the impact bolt 145 are bounced back by receiving a reaction force from the workpiece after the hitting operation, the reaction force from the impact bolt 145 is brought into contact with the impact bolt 145 using the front metal washer 155 as an inclusion. It is configured to be transmitted to the cylindrical weight 163 in a contact state. That is, the front metal washer 155 constitutes a reaction force transmission member, is formed to have a larger diameter than the outer diameter of the rubber ring 153, and is outside the outer peripheral surface of the rubber ring 153 of the front metal washer 155. The front end of the cylindrical weight 163 in the axial direction is in contact. On the other hand, when the cylindrical weight 163 that has received the reaction force from the impact bolt 145 is moved rearward, the coil spring 165 is pushed by the cylindrical weight 163 and elastically deforms, thereby absorbing the reaction force. The coil spring 165 has one axial end abutted against the axial rear end surface of the cylindrical weight 163 and the other axial end abutted with a spring receiving ring 167 fixed to the tool holder 137.

  Further, the hammer drill 101 according to the present embodiment includes a blanking prevention mechanism 181 that prohibits the hammering operation of the hammer bit 119 when the drive motor 111 is energized and driven in a no-load state where the hammer bit 119 is not pushed backward. I have. The air chamber 141a that drives the striker 141 through the action of the air spring communicates with the outside through the breathing hole 141b. The idling prevention mechanism 181 is provided as a means for controlling the opening / closing of the breathing hole 141b. The idling prevention mechanism 181 is placed at an open position where the breathing hole 141b is opened and a closed position where the breathing hole 141b is closed, and an open position where the actuating sleeve 183 opens the breathing hole 141b. The pressurizing spring 185 that urges the operating sleeve 183 to the open position is mainly used. The open position corresponds to the “non-operating position” in the present invention, and the closed position corresponds to the “operating position” in the present invention. The actuating sleeve 183 corresponds to the “air spring actuating member” in the present invention, and the pressure spring 185 corresponds to the “biasing member” in the present invention.

  The operating sleeve 183 is arranged in the outer peripheral region of the cylinder 141 and is movable in the hammer bit major axis direction. The actuating sleeve 183 has an inner diameter flange portion 183a projecting to the inner diameter side at the front end thereof. When the impact bolt 145 is pushed backward together with the hammer bit 119, the operation sleeve 183 is formed by the taper portion 145f between the small diameter portion 145b and the medium diameter portion 145e of the impact bolt 145, that is, the rear taper portion 145f. The inner flange portion 183a is pushed and moved backward to close the breathing hole 141b. The biasing spring 185 is interposed between the operating sleeve 183 and the tool holder 137, and biases the operating sleeve 183 forward to keep the breathing hole 141b open at all times. When the breathing hole 141b is open, the action of the air spring is disabled, and when the breathing hole 141b is closed, the action of the air spring is enabled.

  In the present embodiment, the working sleeve 183 is illustrated in a form constituted by two sleeves divided in the axial direction, but both the sleeves move integrally with each other. Can be a single part. Further, the diameter of the actuating sleeve 183 and the cylinder part diameter of the rear washer 157 of the positioning member 151 are formed to be substantially equal. Therefore, since the cylinder portions of the actuating sleeve 183 and the rear washer 157 interfere with each other, in the present embodiment, the front region of the actuating sleeve 183 and the cylinder portion of the rear washer 157 are staggered in the circumferential direction. A slit is set, which allows placement on the same diameter while avoiding mutual interference.

  Next, the operation of the hammer drill 101 configured as described above will be described. FIG. 3 shows an unloaded state where no pressing force is applied to the main body 103. In this no-load state, the action sleeve 183 is pushed forward by the action of the biasing spring 185 of the idle driving prevention mechanism 181 and is placed at the open position where the breathing hole 141b is opened. In this state, the air chamber 141a communicates with the outside through the breathing hole 141b, and the action of the air spring is invalidated. The operating sleeve 183 pushed by the urging spring 185 is held in the open position with the inner diameter flange portion 183a at the front end thereof abutting against the rear surface of the inner flange portion 157b of the rear washer 157 in the positioning member 151.

  On the other hand, when the user applies a forward pressing force to the main body 103 and the hammer bit 119 is pressed against the workpiece, the impact bolt 145 is moved backward along with the hammer bit 119 pushed back by the workpiece. It is pushed into the piston 129 side. In the impact bolt 145 moved rearward, the rear taper portion 145f abuts against the inner diameter flange portion 183a of the operating sleeve 183, and the operating sleeve 183 moves rearward against the biasing force of the biasing spring 185. Let Thereby, the operation sleeve 183 closes the breathing hole 141b of the air chamber 141a, and the action of the air spring is made effective. Further, the impact bolt 145 is brought into contact with the front metal washer 155 of the positioning member 151 through the front tapered portion 145c. Thus, the pushing force acting on the hammer bit 119 is received by the cylinder 141 which is the main body 103 side member, whereby the main body 103 is positioned with respect to the workpiece. As described above, the front end surface of the cylindrical weight 163 of the impact damper 161 is in contact with the rear surface of the front metal washer 155 of the positioning member 151. This load state is shown in FIG.

  When the drive motor 111 is energized, the drive gear 121 rotates in the horizontal plane by the rotation output. Then, the crank plate 125 rotates in the horizontal plane via the driven gear 123 engaged with and engaged with the drive gear 121, and thereby the piston 129 slides linearly in the cylinder 141 via the crank arm 127. The At this time, if the operating sleeve 183 is in an unloaded state in which the operating sleeve 183 is placed at the open position for opening the breathing hole 141b, the air in the air chamber 141a is discharged or sucked to the outside through the breathing hole 141b. There is no compression spring action. In other words, the hammer bit 119 is prevented from being emptied. On the other hand, in a load state where the operating sleeve 183 is placed at the closed position for closing the breathing hole 141b, the striker 143 moves linearly in the cylinder 141 through the action of the air spring of the air chamber 141a accompanying the sliding operation of the piston 129. The impact bolt 145 is collided (hit) and the kinetic energy is transmitted to the hammer bit 119. Thereby, the hammer bit 119 performs a hammering operation in the major axis direction, and performs a hammering operation on the workpiece.

  When the hammer drill 101 is driven in the hammer drill mode, the transmission gear 131, the transmission shaft 133, and the small bevel gear 134 that mesh with and engage with the drive gear 121 rotated by the rotation output of the drive motor 111 rotate integrally in a horizontal plane. Operate. Then, the large bevel gear 135 that meshes with and engages with the small bevel gear 134 rotates in the vertical plane, and the tool holder 137 and the hammer bit 119 held by the tool holder 137 are rotated together with the large bevel gear 135. . Thus, when driven in the hammer drill mode, the hammer bit 119 performs a hammering operation in the major axis direction and a rotation operation in the circumferential direction to perform a hammer drill operation on the workpiece.

  When the hammer bit 119 is rebounded by a reaction force from the work material after the hammer bit 119 is struck against the work material during the hammer work or the hammer drill work, the impact bolt 145 is caused by the rebound. A reaction force toward the back acts. At this time, the cylindrical weight 163 of the impact damper 161 is in contact with the impact bolt 145 via the front metal washer 155 of the positioning member 151. For this reason, the reaction force of the impact bolt 145 is transmitted to the cylindrical weight 163 in a contact state via the front metal washer 155. In other words, the momentum is exchanged between the impact bolt 145 and the cylindrical weight 163. Due to the transmission of the reaction force, the impact bolt 145 is placed in a substantially stationary state at the striking position, while the cylindrical weight 163 moves rearward, which is the direction in which the reaction force acts. The reaction force of the cylindrical weight 163 moving backward is absorbed by the cylindrical weight 163 elastically deforming the coil spring 165. This state is shown in FIG.

  At this time, the reaction force of the impact bolt 145 naturally acts on the rubber ring 153 placed in contact with the impact bolt 145 via the front metal washer 155. By the way, the transmission of force increases in accordance with the Young's modulus of the object placed in contact. According to the present embodiment, the cylindrical weight 163 of the impact damper 161 is made of hard metal and has a high (large) Young's modulus. On the other hand, the rubber ring 153 is made of rubber and has a low Young's modulus. For this reason, most of the reaction force of the impact bolt 145 is transmitted to the cylindrical weight 163 having a high Young's modulus placed in contact with the metal impact bolt 145 via the hard front metal washer 155. become. Thus, the impact force caused by the rebound generated on the hammer bit 119 and the impact bolt 145 can be efficiently absorbed by the rearward movement of the cylindrical weight 163 and the elastic deformation of the coil spring 165 caused by the movement of the cylindrical weight 163. Thus, the vibration of the hammer drill 101 can be reduced.

  Thus, according to the present embodiment, most of the reaction force that the hammer bit 119 and the impact bolt 145 receive from the workpiece after the hitting operation is transmitted from the impact bolt 145 to the cylindrical weight 163. The impact bolt 145 is placed in a substantially stationary state when viewed from the striking position. For this reason, the reaction force acting on the rubber ring 153 is small, the amount of elastic deformation of the rubber ring 153 due to the reaction force is extremely small, and the subsequent repulsive force is also reduced. Further, the reaction force of the impact bolt 145 can be absorbed by the impact damper 161 composed of the cylindrical weight 163 and the coil spring 165. As a result, the rubber ring 153 can be made hard. As a result, it is possible to optimize the positioning of the main body 103 with respect to the workpiece performed via the rubber ring 153.

  In the present embodiment, the forward biasing force of the cylindrical weight 163 by the coil spring 165 for the impact damper 161 is such that the front metal washer 155 has an inner diameter step portion 137a in the cylindrical hole of the tool holder 137 via the spacer 159. It is received by contacting. In other words, the urging force of the coil spring 165 is restricted so as not to substantially act forward beyond the striking position. Therefore, during the striking operation, when the hammer bit 119 and the impact bolt 145 are held at the striking position by applying a forward pressing force to the main body 103, the coil spring 165 for absorbing the reaction force is provided, It can be prevented that unnecessary force is required to hold the hammer bit 119 and the impact bolt 145.

  Further, according to the present embodiment, the front metal washer 155 acting as a reaction force transmission member that transmits the reaction force of the impact bolt 145 to the cylindrical weight 163 among the constituent members of the positioning member 151 is substantially attached to the cylinder 141. The movement is prohibited in the long axis direction of the hammer bit. As a result, the reaction force transmission position of the front metal washer 155 is made steady, and the contact state of the impact bolt 145 and the cylindrical weight 163 with respect to the front metal washer 155 is ensured, so that the transmission of the reaction force can be improved.

  Further, according to the present embodiment, the reaction force from the workpiece is transmitted to the cylindrical weight 163 via the hammer bit 119 and the impact bolt 145. For this reason, the reaction force from the workpiece is intensively transmitted to the cylindrical weight 163 without being dispersed in the middle of the path. Thereby, the transmission efficiency of the reaction force to the cylindrical weight 163 is increased, and the shock absorbing function can be enhanced.

  In the present embodiment, the cylindrical weight 163 and the positioning member 151 are arranged in parallel in the radial direction at the same position on the long axis of the hammer bit 119. Thereby, it is possible to realize a rational arrangement configuration for space saving. In addition, the impact bolt 145 is brought into contact with the cylindrical weight 163 and the rubber ring 153 through a front metal washer 155 that is a common hard metal plate. Therefore, the reaction force of the impact bolt 145 can be transmitted from one place of the impact bolt 145 to the two paths of the cylindrical weight 163 and the rubber ring 153 via the common front metal washer 155, and the structure can be simplified. It becomes.

(Second embodiment of the present invention)
Next, a second embodiment of the present invention will be described with reference to FIGS. This embodiment is configured to transmit the reaction force (bounce back) at the time of the hitting operation from the hammer bit 119 to the impact damper 161. Except for this configuration, the embodiment includes the idling prevention mechanism 181. The configuration is the same as in the first embodiment. Therefore, among the illustrated members, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified. In this embodiment, the impact bolt 145 includes a large diameter portion 145a, a medium diameter portion 145e, and a small diameter portion 145b, and further includes a small diameter portion 145d on the front side of the large diameter portion 145a. Further, a taper portion 145c is formed at the boundary between the rear small diameter portion 145b and the large diameter portion 145a, and the front metal washer 155 of the positioning member 151 is in contact with the taper portion 145c via the taper surface. On the other hand, the outer diameter of the small diameter portion 145 d on the front side of the impact bolt 145 is set to be smaller than the outer diameter of the hammer bit 119. A predetermined space is set between the outer peripheral surface of the impact bolt 145 and the inner peripheral surface of the tool holder 137.

  On the other hand, the cylindrical weight 163 made of hard metal, which is a constituent member of the impact damper 161, is located between the outer peripheral surface of the positioning member 151 and the outer peripheral front side region of the cylinder 141 and the inner peripheral surface of the tool holder 137. It is arranged and is movable in the major axis direction of the hammer bit while being in contact with the inner peripheral surface of the tool holder 137. The cylindrical weight 163 corresponds to the “weight” in the present invention. The cylindrical weight 163 is formed such that the front region in the axial direction has a smaller diameter than the rear region, and the small diameter portion forms a space between the inner peripheral surface of the tool holder 137 and the outer peripheral surface of the impact bolt 145. It extends forward through. The large-diameter portion 145a of the impact bolt 145 is fitted into the cylindrical hole of the small-diameter extension portion 163a extending forward so as to be relatively movable in the axial direction. Further, the front-end region of the inner peripheral surface of the small-diameter extension portion 163a is A hook-shaped contact portion 163b that protrudes toward the inner diameter side toward the small diameter portion 145d on the front side of the impact bolt 145 is provided. The front surface of the abutting portion 163b is in surface contact with the head peripheral edge portion 119a (rear end portion) of the hammer bit 119 through a tapered surface in a load state in which the hammer bit 119 is pushed backward. Be touched. Accordingly, when the hammer bit 119 bounces after receiving a reaction force from the workpiece after the hammer bit 119 is hit, the reaction force of the hammer bit 119 is placed in direct contact with the hammer bit 119. It is configured to be transmitted to the cylindrical weight 63.

  The contact portion 163b has an inner peripheral surface that is an overhanging end portion closely fitted to the outer periphery of the small-diameter portion 145d on the front side of the impact bolt 145. For this reason, the impact bolt 145 is supported by the cylindrical weight 163 at two locations of the large-diameter portion 154a and the small-diameter portion 145d on the front side, and stabilization of the relative movement operation in the axial direction is achieved.

  Further, the positioning member 151 is configured such that the stepped inner diameter portion of the cylindrical portion 157a of the rear washer 157 is loosely fitted to the front end portion of the cylinder 141, and relative axial movement is allowed. . Then, between the front surface of the front metal washer 155 of the positioning member 151 and the rear surface of the stepped portion 163c of the small diameter extension portion 163a of the cylindrical weight 163, the cylindrical weight 163 moves rearward by a reaction force from the hammer bit 119. A gap having a size necessary for allowing the operation to be performed is set.

  The hammer drill 101 according to the present embodiment is configured as described above. Therefore, in a load state in which the hammer bit 119 is pressed against the workpiece, the hammer bit 119 and the impact bolt 145 are pushed rearward so that the head of the hammer bit 119 is brought into contact with the contact portion 163b of the cylindrical weight 163. Abutted. Further, the taper portion 145 c of the impact bolt 145 contacts the front metal washer 155 of the positioning member 151, and the rear washer 157 contacts the front end portion of the cylinder 141. Thus, the pushing force of the hammer bit 119 is received by the cylinder 141 which is the main body 103 side member. On the other hand, when the impact bolt 145 is pushed rearward, the taper portion 145f on the rear side of the impact bolt 145 comes into contact with the inner diameter flange portion 183a of the operating sleeve 183, and the operating sleeve 183 is applied to the biasing force of the biasing spring 185. Move backwards against it. Thereby, the operation sleeve 183 closes the breathing hole 141b of the air chamber 141a, and the action of the air spring is made effective. This state is shown in FIG.

  In this state, when the drive motor 111 is energized and the hammer bit 119 is struck, the hammer bit 119 is rebounded by the reaction force from the workpiece after the struck operation. The reaction force of the hammer bit 119 is transmitted to the cylindrical weight 163 placed in contact with the hammer bit 119. As a result, the cylindrical weight 163 moves backward, which is the direction in which the reaction force acts, and elastically deforms the coil spring 165. Thus, the impact force caused by the rebound of the hammer bit 119 is absorbed by the impact damper 161, and the hammer drill 101 is reduced in vibration. This state is shown in FIG.

  According to the present embodiment, because the reaction force from the workpiece is transmitted from the hammer bit 119 to the cylindrical weight 163, the cylinder is formed in the rear region of the hammer bit 119 disposed in the tip region of the main body 103. It is easy to secure a wide space for arranging the cylindrical weight 163, and the degree of freedom in designing the weight of the cylindrical weight 163 or the length in the axial direction is high.

(Third embodiment of the present invention)
Next, a third embodiment of the present invention will be described with reference to FIGS. In this embodiment, the rubber ring 155 in the positioning member 151 described in the first embodiment is omitted. Except for this point, the first embodiment includes the idle driving prevention mechanism 181. The configuration is the same as that of the first embodiment. Therefore, among the illustrated members, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified. In this embodiment, the positioning member 151 is constituted only by the metal washer 155. The positioning metal washer 155 has its front surface in contact with the inner diameter step portion 137 a of the tool holder 137, and the rear surface side is stopped by a stop ring 191. In other words, the metal washer 155 is attached to the tool holder 137 in a state in which movement in the long axis direction of the hammer bit is prohibited. As shown in FIG. 3, the front end of the impact bolt 145 is in contact with the tapered portion 145c.

  The cylindrical weight 163, which is a constituent member of the impact damper 161, is urged forward by a coil spring 165, and its front end surface is in contact with the rear surface of the metal washer 155. This configuration is the same as in the first embodiment described above.

  According to the third embodiment configured as described above, when the hammer bit 119 is pressed against the workpiece, the hammer bit 119 and the impact bolt 145 are pushed rearward, whereby the impact bolt 145 is loaded. The front taper portion 145c is in contact with the metal washer 155. Since the metal washer 155 is fixed to the tool holder 137, the pushing force of the hammer bit 119 is received by the tool holder 137 which is a member on the main body 103 side. On the other hand, when the impact bolt 145 is pushed rearward, the taper portion 145f on the rear side of the impact bolt 145 comes into contact with the inner diameter flange portion 183a of the operating sleeve 183, and the operating sleeve 183 is applied to the biasing force of the biasing spring 185. Move backwards against it. Thereby, the operation sleeve 183 closes the breathing hole 141b of the air chamber 141a, and the action of the air spring is made effective. This state is shown in FIG.

  In this state, when the drive motor 111 is energized and the hammer bit 119 is struck, the hammer bit 119 is rebounded by the reaction force from the workpiece after the struck operation. Due to this rebound, a reaction force directed backward is applied to the impact bolt 145. At this time, since the cylindrical weight 163 of the impact damper 161 is in contact with the impact bolt 145 via the metal washer 155, the reaction force of the impact bolt 145 is cylindrical in the contact state via the metal washer 155. It is transmitted to the weight 163, and the cylindrical weight 163 moves rearward. The reaction force of the cylindrical weight 163 moving backward is absorbed by the cylindrical weight 163 elastically deforming the coil spring 165. This state is shown in FIG.

  At this time, since the metal washer 155 is restricted from moving in the axial direction by the tool holder 137 via the retaining ring 191, the reaction force of the impact bolt 145 may also act on the tool holder 137 via the metal washer 155. There is. However, the contact between the metal washer 155 and the retaining ring 191 does not need to be set so as to be in close contact, and a slight gap can be allowed to exist. On the other hand, the contact state of the cylindrical weight 163 with respect to the metal washer 155 is a contact in a state where the elastic force of the coil spring 165 is applied, and can be kept in a completely close state. For this reason, most of the reaction force of the impact bolt 145 is transmitted to the cylindrical weight 163 placed in close contact with the metal washer 155. Thus, the impact force caused by the rebound generated on the hammer bit 119 and the impact bolt 145 can be efficiently absorbed by the rearward movement of the cylindrical weight 163 and the elastic deformation of the coil spring 165 caused by the movement of the cylindrical weight 163. Thus, the vibration of the hammer drill 101 can be reduced. That is, according to the present embodiment, it is possible to rationally absorb the impact force caused by the bounce of the hammer bit 119 after the hitting operation, even though the rubber ring 153 described in the first embodiment is not provided. It became.

  In addition, although embodiment mentioned above demonstrated the hammer drill 101 as an example as an impact type work tool, it is natural that it is applicable not only to the hammer drill 101 but a hammer. If the hammer bit 119 is a hammer that performs only a striking operation, the positioning member 151 that receives the pushing force of the hammer bit 119 may be a housing as a fixing target for fixing the positioning member 151 so as not to move in the axial direction. I do not care. In the above-described embodiment, the transmission path of the reaction force with respect to the cylindrical weight 163 is a method of transmitting from the impact bolt 145 to the cylindrical weight 163 and a method of transmitting from the hammer bit 119 to the cylindrical weight 163. It is possible to have a configuration including both of them. That is, a plurality of cylindrical weights are set in the main body 103, and a reaction force is transmitted from one impact weight to the other cylindrical weight, and a reaction force is transmitted from the hammer bit to the other cylindrical weight. May be. Further, the cylindrical weight 163 that is a constituent member of the impact damper 161 may have a shape other than the cylindrical shape. Further, it can be used in combination with a vibration damping mechanism such as a dynamic vibration absorber or a counterweight for damping the main body 103 by moving linearly in the same direction as the hammer bit 119.

  In the above-described embodiment, the case where the crank mechanism is used as the motion conversion mechanism 113 that converts the rotation output of the drive motor 111 into a linear motion to drive the hammer bit 119 linearly has been described. The mechanism is not limited to the crank mechanism, and for example, a motion conversion mechanism using a swash plate (swash plate) that swings in the axial direction can be used. Further, the idle driving prevention mechanism 181 in the above-described embodiment is a form independent of the impact damper 161 (a parallel form), and an open position for opening the breathing hole 141b based on the movement operation of the impact bolt 145 in the front-rear direction, Although it is configured to move between the closed position where the hole 141b is closed, a configuration in which the moving operation is performed via the impact damper 161 may be adopted. That is, when the impact bolt 145 is pushed into the main body 103 side together with the hammer bit 119 by pressing the hammer bit 119 against the workpiece, the cylindrical weight 163 of the impact damper 161 is pushed back by the impact bolt 145. Accordingly, the actuating sleeve 183 in the idle driving prevention mechanism 181 is pushed through the coil spring 165 to be retracted to the closed position to close the breathing hole 141b, and the cylindrical weight 163 is hammered in the retracted position. You may comprise so that it may act | operate so that the reaction force at the time of the striking operation | movement of the bit 119 may be absorbed. In other words, the impact damper 145 in the use state is moved backward together with the impact bolt to maintain the elastic force of the coil spring 165 and move the operating sleeve 183 of the idle driving prevention mechanism 181 to the operating position in which the operation of the air spring is effective. It is set as the structure to which it moves. In the present embodiment, an example in which both the impact damper 161 and the idle driving prevention mechanism 181 are used in parallel has been described. However, the operating sleeve 183 of the idle driving prevention mechanism 181 appropriately determines the weight of the operating sleeve 183. By adjusting, it is also possible to adopt a configuration in which the cylindrical weight 163 of the impact damper 161 is also used.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side sectional view showing an overall configuration of an electric hammer drill according to a first embodiment of the present invention, showing a load when a hammer bit is pressed against a workpiece. It is an expanded sectional view showing the principal part of a hammer drill. It is a plane sectional view showing a hammer drill, and shows the time of no load in which the hammer bit is not pressed against the workpiece. It is a plane sectional view which shows a hammer drill, and shows the time of load when a hammer bit was pressed against a work material. It is a plane sectional view showing a hammer drill, and shows the time of operation of an impact damper. It is a plane sectional view showing an electric hammer drill concerning a 2nd embodiment of the present invention, and shows the time of load when a hammer bit was pressed against a work material. It is a plane sectional view which similarly shows a hammer drill, and shows the time of operation of an impact damper. It is a plane sectional view showing an electric hammer drill concerning a 3rd embodiment of the present invention, and shows the time of load when a hammer bit was pressed against a work material. It is a plane sectional view which similarly shows a hammer drill, and shows the time of operation of an impact damper.

101 Hammer drill (impact work tool)
103 Main body (tool body)
105 Motor housing 107 Gear housing 109 Hand grip 109a Rotating shaft 109b Elastic spring 111 Drive motor 113 Motion conversion mechanism (drive mechanism)
115 Impact Element 117 Power Transmission Mechanism 119 Hammer Bit (Hammer Actuating Member)
119a Head periphery 121 Drive gear 123 Driven gear 125 Crank plate 126 Eccentric shaft 127 Crank arm 128 Connection shaft 129 Piston 131 Transmission gear 133 Transmission shaft 134 Small bevel gear 135 Large bevel gear 137 Tool holder 137a Inner diameter step portion 141 Cylinder 141a Air chamber 141b Breathing hole 143 striker 145 impact bolt (hammer actuating member)
145a Large diameter portion 145b Small diameter portion 145c Tapered portion 145d Small diameter portion 145e Medium diameter portion 145f Tapered portion 151 Positioning member 153 Rubber ring 155 Front metal washer (inclusion)
157 Rear washer 157a Tube portion 157b Inner flange portion 159 Spacer 161 Impact damper 163 Tube weight (weight)
163a Small diameter extension part 163b Contact part 163c Step part 165 Coil spring (absorbing means)
167 Spring receiving ring 169 Stopper (regulating means)
181 Blanking prevention mechanism 183 Actuating sleeve (air spring actuating member)
183a Inner diameter flange portion 185 Biasing spring (Biasing member)
191 Stop ring

Claims (8)

A tool body;
A hammer actuating member which is disposed in the tip region of the tool body and performs a predetermined hammering operation on the workpiece by linearly moving in the long axis direction;
A drive mechanism that linearly drives the hammer actuating member via an air spring;
The hammer operating member is incorporated in the tool body so as to be movable in the longitudinal direction of the hammer operating member , and the hammer operating member reacts with respect to a reaction force received from the workpiece when the hammer operating member performs a hammering operation on the workpiece. In the reaction force transmission position where it is placed in direct contact with the member or in contact with the hammer actuating member via a hard metal inclusion. A weight to which reaction force is transmitted;
Absorbing means for absorbing the reaction force transmitted to the weight;
An air spring actuating member that is switchable between a non-actuated position for disabling the air spring and an actuating position for enabling the air spring;
An impact type work tool comprising: an urging member that urges the operating member to the non-operating position so that the air spring operating member is placed at the non-operating position. A tool body;
A hammer actuating member which is disposed in the tip region of the tool body and performs a predetermined hammering operation on the workpiece by linearly moving in the long axis direction;
A drive mechanism that linearly drives the hammer actuating member via an air spring;
When the hammer actuating member performs a hammering operation on the workpiece, the reaction force received from the workpiece is placed in direct contact with the hammer actuating member or a hard metal inclusion. A weight at which the reaction force from the hammer actuation member is transmitted at a reaction force transmission position placed in contact with the hammer actuation member via
Absorbing means for absorbing the reaction force transmitted to the weight;
An air spring actuating member that is switchable between a non-actuated position for disabling the air spring and an actuating position for enabling the air spring;
A biasing member that biases the actuating member to a non-actuated position so that the air spring actuating member is placed in the non-actuated position;
An elastic member interposed between the hammer operating member and the tool body, and elastically connecting the hammer operating member to the tool body;
  The weight and the elastic member are arranged in parallel in the radial direction at the same position on the long axis of the hammer operating member,
An impact type wherein the tool body receives a force acting on the hammer actuating member when the hammer actuating member is pressed against the workpiece during the hammering operation via the elastic member. Work tools. A tool body;
A hammer actuating member which is disposed in the tip region of the tool body and performs a predetermined hammering operation on the workpiece by linearly moving in the long axis direction;
A drive mechanism that linearly drives the hammer actuating member via an air spring ;
A cylinder that is fixedly attached to the tool body and in which the driver of the drive mechanism is arranged so as to be linearly movable in the long axis direction;
When the hammer actuating member performs a hammering operation on the workpiece, the reaction force received from the workpiece is placed in direct contact with the hammer actuating member or a hard metal inclusion. A weight at which the reaction force from the hammer actuation member is transmitted at a reaction force transmission position that is placed in contact with the hammer actuation member via
Absorbing means for absorbing the reaction force transmitted to the weight;
An air spring actuating member that is switchable between a non-actuated position for disabling the air spring and an actuating position for enabling the air spring;
A biasing member that biases the actuating member to a non-actuated position so that the air spring actuating member is placed in the non-actuated position;
The impact-type work tool is characterized in that the air spring actuating member is constituted by a sleeve movably disposed on the outer periphery of the cylinder. The impact type work tool according to claim 1 or 3 ,
Before SL interposed between the hammer actuating member and the tool body, the hammer actuating member includes an elastic member connecting the elastic shape to the tool body,
During hammering operation, the impact, characterized in that the force that acting on the hammer actuating member when pressed against the hammer actuating member to the workpiece, and through the resilient member and configured to receive by the tool body Work tool. The impact type work tool according to any one of claims 1 to 4 ,
The hammer actuating member has an impact bolt that receives a driving force by the driving mechanism, and a tool bit that moves linearly when the impact bolt collides,
The impact type work tool characterized in that the impact bolt is configured to transmit a reaction force from the workpiece to the weight through a contact state with the weight. The impact type work tool according to any one of claims 1 to 4 ,
The hammer actuating member has an impact bolt that receives a driving force by the driving mechanism, and a tool bit that moves linearly when the impact bolt collides,
An impact work tool characterized in that the tool bit is configured to transmit a reaction force from the workpiece to the weight through a contact state with the weight. The impact type work tool according to any one of claims 1 to 6 ,
The air spring actuating member is pushed directly by the hammer actuating member that is pushed by the work piece and moved backward when the hammer actuating member is pressed against the work piece during hammering operation. An impact-type work tool characterized by being configured to be moved from a non-actuated position to the actuated position. The impact type work tool according to any one of claims 1 to 7 ,
The impact type work characterized in that the inclusion interposed between the hammer actuating member and the weight is mounted so as not to move in the longitudinal direction of the hammer actuating member with respect to the tool body. tool.

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