JP2008279586A - Impact tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rational structure relating to a striking tool relating to prevention of idling when no load is applied and reduction of reaction force due to rebound of a hammer operating member during hammering.
A striking tool according to the present invention is a striking tool in which a striking element 143 is driven linearly via an air spring of an air chamber 141a to strike a hammer actuating member 145, 119. When the load 119 is pressed against the workpiece, the tool body 103 is positioned with respect to the workpiece by abutting with the positioning member 151, and the reaction force due to the rebound from the workpiece is absorbed at the positioning position. It has positioning elastic bodies 165F and 165R that can be elastically deformed. Further, when no load is applied when the hammer actuating members 145 and 119 are not pressed against the workpiece, the communication portion 141b is placed in an open position to make the pressure fluctuation of the air chamber 141a impossible, and when the load is applied, the communication portion 141b is closed. It has a communication portion opening / closing member 143 that enables the pressure variation of the air chamber 141a by moving to the position.
[Selection] Figure 2

Description

  The present invention relates to a technique for preventing idling when no load is applied to a striking tool that performs a linear hammering operation on a workpiece, and a technique for reducing a reaction force received from the workpiece during the hammering operation.

2. Description of the Related Art A hitting tool having a function of preventing a hammer bit from being blanked when there is no load when the hammer bit is not pressed against a workpiece is widely known. A hitting tool having such a blanking prevention function is disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-212370 (Patent Document 1). The hitting tool described in the publication is a hammer drill, and when the piston moves linearly in the cylinder, the striker moves linearly via the pressure fluctuation (spring action) of the air chamber and hits the hammer bit via the impact bolt. It is a configuration. The cylinder has a vent hole that allows the air chamber to communicate with the outside. By placing the vent hole in an open state, the spring action of the air chamber is disabled and tool biting is prevented. The In order to perform hammering work on the workpiece, when the hammer bit is pressed against the workpiece and pushed into the tool body side, the air hole is closed by the sleeve that is moved backward together with the hammer bit, so that the air is closed. The chamber can be spring-operated, and the hammer bit can be struck.
By the way, the actual hammering operation is performed in a state where the operator applies a pressing force directed forward to the tool body and presses the hammer bit against the workpiece. The tool body is positioned relative to the workpiece at this time by the impact bolt that is moved backward together with the hammer bit pushed into the tool body side (rear) contacting an inelastic body (for example, a cylinder) on the tool body side. Made. When a hammering operation is performed in this positioning state, the hammer bit rebounds with a reaction force received from the workpiece, and the reaction force is transmitted to the tool body. For this reason, in the conventional hammer, a shock absorbing material (rubber ring) is interposed between the impact bolt and the non-elastic body on the tool body side, and the reaction force due to the bounce of the hammer bit is reduced by the shock absorbing action of the shock absorbing material. Yes.

However, in the conventional impact tool, there is still room for improvement with respect to the structure for preventing idling when no load is applied and the structure for reducing the reaction force due to rebounding of the hammer bit during hammering.
Japanese Patent Laid-Open No. 2003-212370

  In view of this point, an object of the present invention is to provide a rational structure relating to a striking tool for preventing a blank shot when no load is applied and reducing a reaction force due to a rebound during a hammer operation.

  In order to achieve the above object, a preferred form of the impact tool according to the present invention is an impact tool for performing a predetermined hammer operation on a workpiece by an impact operation in the longitudinal direction of a hammer operating member. A cylinder accommodated therein, a driver that linearly moves in the longitudinal direction of the hammer actuating member, an impactor that linearly moves in the longitudinal direction of the hammer actuating member in the cylinder, and a driver and an impactor in the cylinder And an air chamber formed between the air chamber and a linearly operated striking member through a pressure variation of the air chamber accompanying a linear motion of the driver, and the hammer actuating member strikes the hammer actuating member. A predetermined hammering operation is performed. The “predetermined hammering operation” in the present invention refers to not only a hammering operation in which the hammer operating member performs only a long-axis hitting operation, but also a long-axis hitting operation and a rotation operation around the long-axis direction. A hammer drilling operation is preferably included. The “hammer actuating member” in the present invention typically corresponds to a tool bit and an impact bolt that transmits a striking force to the tool bit. The “driver” in the present invention typically corresponds to a piston that slides in the bore of the cylinder. However, the piston is integrated with the cylinder, and the cylinder moves linearly together with the piston. You may be the aspect which performs.

  The preferable form of the impact tool which concerns on this invention has a positioning member and a positioning elastic body. The positioning member is abutted against the hammer actuating member when the hammer actuating member is pressed against the workpiece and pushed toward the driver side, and when the no-load when the hammer actuating member is not pushed against the workpiece, It is set as the structure spaced apart from a hammer operation member. The positioning elastic body contacts the positioning member at the time of loading to position the tool main body with respect to the workpiece, and at the positioning position, when the hammer operating member performs a hammer operation on the workpiece, the hammer operating member The reaction force caused by the rebound from the workpiece that is input from the positioning member through the positioning member is absorbed by elastic deformation. The “positioning elastic body” in the present invention typically corresponds to a spring. In the present invention, the reaction force acting on the hammer actuating member during the hammering operation is transmitted from the hammer actuating member to the positioning member, and the positioning member is moved backward. The positioning elastic body is elastically deformed by the backward movement of the positioning member. That is, according to the present invention, the reaction force received by the hammer operating member from the workpiece can be absorbed by the elastic deformation of the positioning elastic body caused by the backward movement of the positioning member, thereby reducing the vibration of the impact tool. Is realized.

  Moreover, the preferable form of the striking tool which concerns on this invention has a communicating part for the idle shot prevention which connects an air chamber and the exterior, and a communicating part opening-and-closing member for opening and closing a communicating part. The “communication portion” of the present invention typically corresponds to a vent hole formed in a cylinder. The communication part opening / closing member is constituted by a striker arranged inside the cylinder or a movable member (cylindrical member) arranged outside the cylinder, and a closed position for closing the communication part and an open position for opening the communication part It is possible to move between. The communication portion opening / closing member is placed in an open position where the communication portion is opened when no load is applied, thereby disabling pressure fluctuations in the air chamber. As a result, the linear motion of the striker when the driver is driven is stopped to prevent the hammer actuating member from being idle. In addition, the communication portion opening / closing member is moved by the hammer actuating member or the positioning member to a closed position that closes the communication portion when a load is applied, thereby enabling pressure fluctuations in the air chamber. Thus, when the driving element is driven, the striking element is linearly operated through the pressure fluctuation of the air chamber, and the hammer actuating member can perform the striking action by the striking element.

  According to the further form of the impact tool which concerns on this invention, it is set as the structure which has an elastic member which urges | biases the positioning member ahead spaced apart from a striker. The “elastic member” in the present invention typically corresponds to a spring. The positioning member biased in the direction away from the striker by the elastic member is held at the front position when no load is applied. As a result, the communication portion opening / closing member that opens and closes the communication portion for preventing idling is moved to the open position where the communication portion is opened or allowed to move. For this reason, when the driving element is driven, the air in the air chamber is discharged or sucked to the outside through the communicating portion. That is, according to the present invention, the reliability of the hammering prevention function of the hammer operating member can be improved.

  According to the further form of the impact tool which concerns on this invention, it is set as the structure by which the positioning elastic body and the elastic member were arrange | positioned in parallel with radial direction in the same position on a hammer operation member long axis. By adopting such a configuration, the positioning elastic body and the elastic member can be rationalized using the internal space in the direction intersecting the long axis direction of the tool body without changing the long axis direction length of the work tool. Can be arranged.

  According to the further form of the impact tool which concerns on this invention, it has a dynamic vibration damper. The dynamic vibration absorber has a weight capable of linear motion in a state in which an urging force by an elastic element is applied, and the weight moves in the long axis direction of the hammer operating member to perform vibration suppression during hammering work. Is done. According to the present invention, it is possible to reduce the vibration in the longitudinal direction of the hammer actuating member that occurs in the tool body during the hammering operation by the cooperation of the weight and the elastic element constituting the dynamic vibration absorber.

  According to the further form of the impact tool which concerns on this invention, the positioning elastic body is comprised by the elastic element as a structural member of a dynamic vibration damper. According to the present invention, the tool main body is positioned with respect to the workpiece during the hammering operation by the elastic element of the dynamic vibration absorber. Thereby, the dynamic vibration absorber acts as a vibration suppression mechanism that suppresses vibration in the long axis direction of the hammer generated in the tool main body during the hammer operation by the cooperation of the weight and the elastic element, and the elastic element of the dynamic vibration absorber is The hammer operating member is elastically deformed by the reaction force received from the workpiece, thereby absorbing the reaction force and reducing the transmission of the reaction force to the tool body. As described above, according to the present invention, the elastic element of the dynamic vibration absorber is configured to have the functions of positioning the tool body and absorbing the reaction force, thereby reducing the number of parts related to vibration reduction. The structure can be simplified. Note that the elastic element that also serves as the positioning elastic body is set so that a normal operator has a surplus pressure that is equal to or greater than the force that presses the hammer operating member against the workpiece.

  According to the further form of the impact tool which concerns on this invention, while the positioning member is arrange | positioned on the outer side of a hammer operation member, it is comprised by the annular member which can contact | abut to the outer-diameter part of the said hammer operation member from back. Further, behind the positioning member, an opposing member facing the positioning member at a predetermined interval is arranged in a state in which rearward movement is restricted by the tool body. And the positioning elastic body is comprised by the coil spring arrange | positioned in the interposed form between the positioning member and the opposing member. As described above, according to the present invention, the positioning elastic body is configured by the coil spring, so that, for example, the reaction force is absorbed by the rubber ring, and the reaction force absorption effect is enhanced by setting the spring constant small. Can do.

  According to the further form of the impact tool according to the present invention, the coil spring is disposed so that the axial front region thereof overlaps the outside of the positioning member, and the front end portion that contacts the positioning member is positioned with the hammer actuating member. It is set ahead of the contact point of the member. By adopting such a configuration, it is possible to shorten the length of the work tool in the long axis direction while securing a predetermined elastic deformation amount necessary for absorbing the reaction force for the coil spring.

According to the further form of the impact tool according to the present invention, either the positioning member or the opposing member has a positioning member at the stage before the coil spring reaches a close contact state when the reaction force is absorbed by the compression deformation of the coil spring. And a stopper that elastically deforms in contact with either one of the opposing members. The “stopper” in the present invention typically corresponds to urethane or rubber. In addition, as an aspect of “providing” in the present invention, any of an aspect of providing in a ring shape in the circumferential direction and an aspect of arranging in a dotted manner in the circumferential direction are suitably included.
During a hammer operation, if a pushing load exceeding the set value is applied to the coil spring and the coil spring is in close contact, that is, if adjacent coils are in close contact with each other, a large impact is applied to the coil spring, causing the coil spring to break or counteract by the coil spring. There is a possibility that the force absorption effect cannot be obtained and the reaction force is directly transmitted to the tool body side. However, according to the present invention, the coil spring can be protected from impact by contacting the positioning member or the opposing member before the coil spring reaches the close contact state, and the effect of absorbing the reaction force can be further enhanced. .

  According to the present invention, the striking tool is provided with a rational structure relating to prevention of idling at no load and reduction of reaction force due to rebound at the time of hammering.

(First embodiment of the present invention)
Hereinafter, a first embodiment of the present invention will be described in detail with reference to FIGS. This embodiment will be described using an electric hammer as an example of an impact tool. FIG. 1 is a side sectional view showing the overall configuration of the electric hammer according to the present embodiment, FIG. 2 and FIG. 3 are enlarged sectional views showing main parts of the electric hammer, respectively. FIG. FIG. 3 shows a load state in which the hammer bit is pressed against the workpiece.

  As shown in FIG. 1, the electric hammer 101 according to the present embodiment generally includes a main body 103 that forms an outline of the electric hammer 101, and a tool in the tip region (left side in the drawing) of the main body 103. A hammer bit 119 detachably attached via a holder 137 and a hand grip 109 gripped by an operator connected to the opposite side of the hammer bit 119 of the main body 103 are mainly configured. 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. 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 and the striking element 115. 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 hand grip 109 is provided with a slide switch 109a that energizes and drives the drive motor 111 when the operator performs a slide operation.

  The motion conversion mechanism 113 includes a drive gear 121 that is rotationally driven in a horizontal plane by the drive motor 111, a crank plate 125 having a driven gear 123 that meshes and engages with the drive gear 121, and a predetermined distance from the rotation center of the crank plate 125. A crank arm 127 having one end connected in an eccentric manner to an eccentric position via an eccentric shaft 126, and a piston 129 as a driver attached to the other end of the crank arm 127 via a connecting shaft 128 It is composed mainly of. The crank plate 125, the crank arm 127, and the piston 129 constitute a crank mechanism.

  As shown in FIGS. 2 and 3, the striking element 115 is disposed on the striker 143 as a striking element slidably disposed on the bore inner wall of the cylinder 141, and slidably disposed on the tool holder 137. An impact bolt 145 serving as an intermediate for transmitting 143 kinetic energy to the hammer bit 119 is mainly used. An air chamber 141 a is formed in the cylinder 141 between the piston 129 and the striker 143. 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.

An air chamber 141 a for driving the striker 143 through the action of the air spring is communicated with the outside through an air blow hole 141 b for preventing idling formed in the cylinder 141. In a no-load state in which the hammer bit 119 is not pressed against the workpiece, that is, in a state in which the impact bolt 145 is not pressed in, the striker 143 can be moved to a front position where the vent hole 141b is opened ( (See FIG. 2). On the other hand, in a load state in which the operator applies a forward pressing force to the main body 103 and presses the hammer bit 119 against the workpiece, the striker 143 is pushed by the impact bolt 145 that is moved backward to make the vent hole 141b. It is moved to the rear (closed) rear position (see FIG. 3). The communication hole 141b corresponds to the “communication portion” in the present invention.
Thus, the vent hole 141b of the air chamber 141a is configured to be opened and closed by the striker 143. When the vent hole 141b is opened, the action of the air spring is invalidated, and when the vent hole 141b is closed. The action of the air spring is effective. In other words, the air hole 141b and the striker 143 constitute an air chamber open type air blow prevention mechanism that prevents the hammer bit 119 from being driven (empty fire) in an unloaded state. The striker 143 corresponds to the “communication portion opening / closing member” in the present invention.

  In addition, the electric hammer 101 according to the present embodiment includes a dynamic vibration absorber 161 for suppressing vibration generated in the main body 103 during the hammering operation. An annular space is formed between the inside of the gear housing 107 that houses the cylinder 141 and the outside of the cylinder 141. The dynamic vibration absorber 161 mainly includes a cylindrical weight 163 disposed in the annular space, and front and rear urging springs 165F and 165R disposed on the front and rear of the weight 163 in the longitudinal direction of the hammer bit. Is done. The biasing springs 165F and 165R correspond to “elastic elements” in the present invention. The front and rear urging springs 165F and 165R impart opposing resilient force to the weight 163 when the weight 163 moves in the longitudinal direction of the hammer bit 119. The portion of the gear housing 107 that accommodates the cylinder 141 is formed by a tubular member (barrel) 108 as a separate member. The tubular member 108 and the gear housing 107 are structured to be fixed to each other. There is substantially one component.

The weight 163 is disposed so that the center thereof coincides with the long axis of the hammer bit 119, and is slidable in a state where the outer peripheral surface thereof is in contact with the inner peripheral surface of the cylindrical member 108. The front and rear urging springs 165F and 165R are respectively constituted by compression coil springs, and are arranged so that their centers coincide with the long axis of the hammer bit 119, as with the weight 163. One end (rear end) of the rear biasing spring 165 </ b> R is in contact with a spring receiving surface 107 a formed on the gear housing 107, and the other end (front end) is in contact with the axial rear end of the weight 163. In addition, one end (rear end) of the front biasing spring 165 </ b> F is in contact with the front end in the axial direction of the weight 163, and the other end (front end) is in contact with the spring receiving member 167.
The spring receiving member 167 is a ring having an overhanging flange portion 167a, and is fitted to the inner peripheral surface of the tubular hole of the tubular member 108 so as to be slidable in the long axis direction of the hammer bit, and the flange portion 167a. The stepped contact surface 108a formed on the tubular member 108 is contacted from the rear and is always held at the contact position.

  The dynamic vibration absorber 161 configured as described above has a damping function against shocking and periodic vibrations generated during hammering (when the hammer bit 119 is driven). In other words, the weight 163 and the urging springs 165F and 165R, which are the vibration damping elements in the dynamic vibration absorber 161, cooperate with the main body 103 of the electric hammer 101 that is the object of vibration damping to perform passive vibration damping. Thereby, the vibration of the electric hammer 101 is effectively suppressed.

  The electric hammer 101 has an impact bolt 145 that is pushed backward together with the hammer bit 119 (piston 129 side) when an operator applies a forward pressing force to the main body 103 to press the hammer bit 119 against the workpiece. The main body 103 is positioned with respect to the workpiece by contacting the main body side member. In the present embodiment, this positioning is performed by the biasing springs 165F and 165R of the dynamic vibration absorber 161 described above via the positioning member 151.

  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. It is a unit part composed of the hard rear metal washer 157, and is fitted into the small diameter portion 145b of the impact bolt 145 in a loose fit. The impact bolt 145 has a stepped portion having a large-diameter portion 145a slidably fitted to the inner peripheral surface of the cylindrical portion of the tool holder 137 and a small-diameter portion 145b formed on the rear side of the large-diameter portion 145a. A tapered portion 145c is formed between the outer peripheral surface of the large diameter portion 145a and the outer peripheral surface of the small diameter portion 145b. And the positioning member 151 is arrange | positioned between the outer peripheral surface of the small diameter part 145b, and the cylindrical inner peripheral surface of the cylindrical member 108. FIG.

  When a load is applied when the hammer bit 119 is pressed against the workpiece by the operator, the taper portion 145c of the impact bolt 145 moved backward together with the hammer bit 119 contacts the positioning member 151 at a predetermined retracted position, and the positioning member 151 is moved. Push backwards. The positioning member 151 pushed backward is brought into contact with the front end surface of the spring receiving member 167. That is, the pressing force of the hammer bit 119 against the workpiece by the operator is received in a resilient manner by the biasing springs 165F and 165R, thereby positioning the main body 103 with respect to the workpiece. Therefore, the urging springs 165F and 165R are set so that the normal worker has a residual pressure that is equal to or greater than the force with which the hammer bit 119 is pressed against the workpiece.

  The positioning member 151 is biased forward by a coil spring 159. As a result, the positioning member 151 moves to a front position where the front end in the axial direction of the front metal washer 155 comes into contact with the rear end portion 137a of the tool holder 137 when the hammer bit 119 is not pressed against the workpiece. And moved and held. Thus, the impact bolt 145 can be placed at a position away from the striker 143 by moving the positioning member 151 to the forward position. As a result, the hammer bit 119 is prevented from being blown by the striker 143 when the piston 129 is driven in a no-load state. Further, the positioning member 151 held at the front position is separated from the tapered portion 145c of the impact bolt 145. The coil spring 159 is arranged outside the cylinder 141 in parallel with the inner diameter side of the urging spring 165F on the front side of the dynamic vibration absorber 161, and a retaining ring whose one end (rear end) in the axial direction is fixed to the cylinder 141. The other end is in contact with the rear end face of the rear metal washer 157 of the positioning member 151.

  Next, the operation of the electric hammer 101 configured as described above will be described. When the drive motor 111 shown in FIG. 1 is energized and driven, the drive gear 121 rotates in a 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 hammer bit 119 is in an unloaded state where it is not pressed against the workpiece, the positioning member 151 urged forward by the coil spring 159 is the rear end of the tool holder 137 as shown in FIG. The striker 143 is moved to the front position where the vent hole 141b is opened or is allowed to move. For this reason, when the piston 129 is moved forward, the air in the air chamber 141a is discharged or sucked to the outside through the vent hole 141b, and the action of the compression spring does not occur in the air chamber 141a. In other words, the hammer bit 119 is prevented from being emptied.

  On the other hand, in the load state in which the hammer bit 119 is pressed against the workpiece, as shown in FIG. 3, the striker 143 is pushed backward by the impact bolt 145 pushed backward together with the hammer bit 119, and the ventilation hole 141b. Close. For this reason, the striker 143 linearly moves in the cylinder 141 by the action of the air spring in the sliding movement of the piston 129 and collides with (impacts) the impact bolt 145, thereby reducing its kinetic energy. 119. Thereby, the hammer bit 119 performs a hammering operation in the major axis direction, and performs a hammering operation on the workpiece.

  As described above, the hammering operation is performed in a load state in which the hammer bit 119 is pressed against the workpiece. The hammer bit 119 that is pushed backward by being pressed against the workpiece causes the impact bolt 145 to move backward. The impact bolt 145 that moves backward pushes the positioning member 151 backward. The rear metal washer 157 of the positioning member 151 is brought into contact with the spring receiving member 167 of the dynamic vibration absorber 161. In this manner, the pressing force of the hammer bit 119 against the workpiece by the operator is received in a resilient manner by the biasing springs 165F and 165R of the dynamic vibration absorber 161. As a result, the main body 103 is positioned with respect to the workpiece, and the hammering operation is performed in this state. During the hammering operation, the dynamic vibration absorber 161 performs passive vibration suppression by the weight 163 and the biasing springs 165F and 165R cooperating with the periodic vibration in the long axis direction of the hammer bit generated in the main body 103. Acting as a vibration control mechanism to perform, vibration of the electric hammer 101 can be effectively suppressed.

  In addition, after the hammer bit 119 strikes the workpiece, the hammer bit 119 receives a reaction force from the workpiece and rebounds. The force due to the rebound, that is, the reaction force moves the impact bolt 145, the positioning member 151, and the spring receiving member 167 rearward, and elastically deforms the biasing springs 165F and 165R. That is, the reaction force due to the rebound of the hammer bit 119 is absorbed by the elastic deformation of the urging springs 165F and 165R, and transmission to the main body 103 is reduced. At this time, the rear metal washer 157 of the positioning member 151 opposes the front end surface of the cylinder 141 with a predetermined gap so as to be able to come into contact therewith, thereby defining the maximum retracted position of the positioning member 151. For this reason, the reaction force absorbing action by the urging springs 165F and 165R is performed within the range of the gap.

  As described above, in the present embodiment, the reaction force that the hammer bit 119 receives from the workpiece after the positioning of the main body 103 with respect to the workpiece and the hammer bit 119 is performed prior to the hammering operation. Is absorbed using the urging springs 165F and 165R of the dynamic vibration absorber 161. In other words, the reaction force absorbing spring and the dynamic vibration absorber 161 are used as a common component, which reduces the number of components relating to vibration reduction and simplifies the structure.

  Further, the reaction force caused by the rebound of the hammer bit 119 is input to the weight 163 via the impact bolt 145, the positioning member 151, the spring receiving member 167, and the urging springs 165F and 165R. That is, the reaction force caused by the rebound of the hammer bit 119 acts as a vibration means for positively vibrating (driving) the weight 163 of the dynamic vibration absorber 161. Thereby, the dynamic vibration absorber 161 acts as an active vibration suppression mechanism by forced vibration that actively drives the weight 163, and can more effectively suppress vibration generated in the main body 103 during hammering. For this reason, for example, the amount of vibration input to the dynamic vibration absorber 161 is small, even though the demand for vibration suppression is high, such as when machining is performed while applying a strong pressing force to the main body 103. Even in a work mode in which the dynamic vibration absorber 161 does not operate sufficiently, a sufficient vibration damping function can be ensured.

  In this embodiment, the main body 103 is positioned by the urging springs 165F and 165R. Therefore, it is allowed to move the impact bolt 145 further rearward by bending the biasing springs 165F and 165R by strongly pressing the hammer bit 119 against the workpiece. That is, according to the present invention, when the hammer bit 119 is strongly pressed against the workpiece, the pushing amount of the striker 143 toward the piston 129 can be increased, so that the sucking performance is improved. The suction of the striker 143 means that the piston 129 moves backward to expand the air chamber 141a, thereby cooling the air in the air chamber 141a and reducing the pressure of the air chamber 141a, and the striker 143 is based on the air pressure. Refers to the phenomenon of moving backward.

  Further, in the present embodiment, a biasing spring 165F on the front side of the dynamic vibration absorber 161 and a coil spring 159 that biases the positioning member 151 forward are arranged in parallel in the radial direction at the same position on the long axis of the hammer bit 119. The configuration is arranged in a shape. Thereby, it is possible to realize a rational arrangement configuration for space saving. In the present embodiment, the rear metal washer 157 of the positioning member 151 is opposed to the front end surface of the cylinder 141 so as to be in contact with the front end surface of the cylinder 141 in a load state where the hammer bit 119 is pressed against the workpiece. The maximum retracted position of the positioning member 151 is defined. Thereby, it is possible to restrict the hammer bit 119 and the impact bolt 145, the striker 143, and the like pushed by the hammer bit 119 from moving backward beyond the maximum retracted position.

  In the present embodiment, the weight 163 and the urging springs 165F and 165R constituting the dynamic vibration absorber 161 are arranged in an annular shape outside the cylinder 141. Thereby, the arrangement which effectively utilizes the outer peripheral space of the cylinder 141 becomes possible. Further, the weight 163 and the urging springs 165F and 165R can be arranged so that the center of gravity of the weight 163 and the urging springs 165R and 165R coincide with the major axis of the hammer bit 119. (Rotational force in the direction) can be prevented from acting.

  Next, a modified example of the first embodiment will be described with reference to FIGS. In the first embodiment described above, the reaction force received by the hammer bit 119 from the workpiece is absorbed using the urging springs 165F and 165R of the dynamic vibration absorber 161. A compression coil spring 171 is provided as a dedicated member for absorbing force. Except for this point, the configuration is the same as in the first embodiment. For this reason, about the same component, the code | symbol same as the code | symbol used by description of 1st Embodiment is attached | subjected, and the description is abbreviate | omitted. The compression coil spring 171 corresponds to the “positioning elastic body” in the present invention.

  The compression coil spring 171 is disposed outside the cylinder 141, and one end (rear end) in the long axis direction is brought into contact with the front surface of the spring receiving ring 173 fixed to the tubular member 108 via the retaining ring 172. The end (front end) is brought into contact with the rear surface of the spring receiving member 175 as a reaction force transmitting member. The spring receiving member 175 is a ring-shaped component having an overhanging flange portion 175a, and is fitted to the inner peripheral surface of the cylindrical hole of the cylindrical member 108 so as to be slidable in the long axis direction of the hammer bit. Then, it is pushed forward (leftward in the figure) by the compression coil spring 171, and the flange portion 175 a is normally held at a position in contact with the stepped locking surface 108 a of the cylindrical member 108 from the rear. In this contact state, the front end of the spring receiving member 175 is in contact with the rear surface of the rear metal washer 157 of the positioning member 151. For this reason, in a no-load state where the hammer bit 119 is not pressed against the workpiece, the positioning member 151 is brought into contact with the rear end portion 137a of the tool holder 137 and is separated from the tapered portion 145c of the impact bolt 145. ing. This state is shown in FIG.

  According to the modified example configured as described above, when the hammer bit 119 is pressed against the workpiece and the impact bolt 145 is retracted together with the hammer bit 119 in order to perform the hammering operation, the impact bolt 145 The tapered portion 145 c abuts on the front metal washer 155 of the positioning member 151. The positioning member 151 is in contact with a spring receiving member 175 that receives the urging force of the compression coil spring 171 by the rear metal washer 157. For this reason, the pressing force of the hammer bit 119 against the workpiece is received by the compression coil spring 171 in a resilient manner. This state is shown in FIG. As a result, the main body 103 is positioned with respect to the workpiece, and the hammering operation is performed in this state.

When the hammer bit 119 hits the workpiece, and the hammer bit 119 is rebounded by a reaction force from the workpiece, the force due to the rebound, that is, the reaction force, is the hammer bit 119 and the positioning member 151. Then, the spring receiving member 175 is moved rearward, and the compression coil spring 171 is elastically deformed. That is, the reaction force caused by the bounce of the hammer bit 119 is absorbed by the elastic deformation of the compression coil spring 171 and transmission to the main body 103 is reduced. This state is shown in FIG.
Note that prevention of idling in the modification example is the same as that in the first embodiment described above.

(Second embodiment of the present invention)
Next, a second embodiment of the present invention will be described in detail with reference to FIGS. This embodiment will be described using a hammer drill as an example of a striking tool. FIGS. 7 and 8 are side sectional views schematically showing the overall configuration of the hammer drill. FIG. 7 shows an anti-hit state (when no load is applied), and FIG. 9 and 10 are enlarged views of a part A in FIG. 8, and FIG. 10 shows a reaction force absorbing state. As shown in FIG. 7 and FIG. 8, the hammer drill 201 generally includes a main body 203 that forms an outline of the hammer drill 201 and a tip region (left side in the drawing) of the main body 203 via a tool holder 237. A hammer bit 219 that is detachably attached and a hand grip (not shown for convenience) gripped by an operator connected to the opposite side of the hammer bit 219 of the main body 203 are mainly configured. The main body 203 corresponds to the “tool main body” in the present invention. The hammer bit 219 is held by the tool holder 237 so that the hammer bit 219 can be reciprocally moved in the major axis direction and the relative rotation in the circumferential direction is restricted. For convenience of explanation, the hammer bit 219 side is referred to as the front, and the hand grip side is referred to as the rear.

  The main body 203 includes a motor housing 205 (a part of which is shown on the right side of FIGS. 7 and 8) that houses a drive motor 211 (the tip of the motor output shaft is shown), a motion conversion mechanism 213, and a power transmission mechanism. 214 and the gear housing 207 which accommodates the striking element 215 are mainly constituted. The rotation output of the drive motor 211 is appropriately converted into a linear motion by the motion conversion mechanism 213 and then transmitted to the striking element 215, and the hammer bit 219 is moved in the major axis direction (left-right direction in FIG. 7) via the striking element 215. Generates an impact force on. The rotation output of the drive motor 211 is appropriately decelerated by the power transmission mechanism 214 and then transmitted to the hammer bit 219, and the hammer bit 219 is rotated in the circumferential direction.

  The motion conversion mechanism 213 rotates integrally with the drive gear 221 that is rotationally driven in the vertical plane by the drive motor 211, the driven gear 223 that meshes with and engages with the drive gear 221, and the driven gear 223 via the intermediate shaft 225. Rotating body 227, swinging ring 229 swinging in the major axis direction of hammer bit 219 by rotation of rotating body 227, and cylindrical piston 241 that reciprocates linearly by swinging swinging ring 229 are mainly configured. Is done. The cylindrical piston 241 has a configuration in which a cylinder and a piston are integrally formed, and is slidably supported by a cylindrical cylinder guide 235. The cylindrical piston 241 corresponds to a “cylinder” and a “driver” in the present invention. The intermediate shaft 225 is disposed parallel (horizontally) to the major axis direction of the hammer bit 219, and the outer peripheral surface of the rotating body 227 attached to the intermediate shaft 225 is inclined at a predetermined inclination angle with respect to the axis of the intermediate shaft 225. Is formed. The swing ring 229 is supported on the inclined outer peripheral surface of the rotating body 227 through a bearing 226 so as to be relatively rotatable, and intersects with the major axis direction of the hammer bit 219 and the major axis direction as the rotating body 227 rotates. It is swung in the direction of The oscillating mechanism is configured by the rotator 227 and the oscillating ring 229 supported by the rotator 227 via the bearing 226 so as to be relatively rotatable.

  In the upper end region of the rocking ring 229, a rocking rod 228 that protrudes integrally upward (radially) is provided, and the rocking rod 228 is engaged at the rear end of the cylindrical piston 241. The portion 224 is engaged in a loose fit. The cylindrical piston 241 is slidably disposed in the cylinder guide 235, is driven by the swinging motion of the swinging ring 229 (longitudinal direction component of the hammer bit 219), and is linear along the cylinder guide 235. Perform the action.

  The power transmission mechanism 214 includes a first transmission gear 231 that is rotationally driven in the vertical plane from the drive motor 211 via the drive gear 221 and the intermediate shaft 225, and a second transmission gear that meshes with and engages with the first transmission gear 231. 233, and a cylinder guide 235 that rotates together with the second transmission gear 233. The rotational driving force of the cylinder guide 235 is transmitted to the tool holder 237 and further to the hammer bit 219 held by the tool holder 237. The cylinder guide 235 is attached to the gear housing 207 so as to be rotatable about the major axis in a state where movement in the major axis direction is restricted.

  The striking element 215 is slidably disposed on the tool holder 237 and striker 243 as a striking element slidably disposed on the bore inner wall of the cylindrical piston 241, and the hammer bit 219 is used for operating energy of the striker 243. And an impact bolt 245 as an intermediate that transmits to the main body. The striker 243 is driven via an air spring in the air chamber 241a of the cylindrical piston 241 in accordance with the sliding operation of the cylindrical piston 241 and collides with the impact bolt 245 slidably disposed on the tool holder 237 (blows). The impact force is transmitted to the hammer bit 219 via the impact bolt 245. The cylindrical piston 241, the striker 243, and the impact bolt 245 constitute a tool driving mechanism. The impact bolt 245 and the hammer bit 219 correspond to the “hammer actuating member” in the present invention.

  The cylinder portion of the cylindrical piston 241a is formed with an air blow preventing hole 241b that communicates the air chamber 241a with the outside. At the front position of the striker 243, a ring case 257 having an O-ring 258 for preventing idling is disposed. As shown in FIGS. 9 and 10, the striker 243 has a small-diameter striking portion 243a that strikes the impact bolt 245 on the front end side (front end side), and projects outward on the outer periphery of the end portion of the striking portion 243a. A flange portion 243b is formed. When the striker 243 is moved further forward than the normal striking position (position shown in FIG. 8), the flange portion 243b of the striking portion 243a moves forward beyond the O-ring 258, whereby the striker 243 is It is captured elastically by an O-ring 258. This state is shown in FIG. As described above, when the striker 243 is placed at the front position supplemented by the O-ring 258, when the cylindrical piston 241 moves in the front-rear direction, the vent hole 241b for preventing air strike is opened to communicate with the outside. Is done. For this reason, the air in the air chamber 241a is discharged or sucked to the outside through the vent hole 241b, and the driving of the striker 243 in an unloaded state, that is, idling is prevented.

On the other hand, as shown in FIG. 8, in the load state in which the hammer bit 219 is pressed against the workpiece, the impact bolt 245 moved backward together with the hammer bit 219 pushes the tip of the hitting portion 243a, thereby causing the hitting portion. The flange portion 243b of 243a escapes from the O-ring 258. For this reason, the striker 243 is moved to the rear impact position while being supplemented by the O-ring 258 is released. When the cylindrical piston 241 moves in the front-rear direction, the striker 243 placed at the striking position maintains the air hole 241b for preventing idling closed. Thereby, the effect | action of the air spring of the air chamber 241a is made effective. The vent hole 241b, the O-ring 258, and the striker 243 constitute an idle driving prevention mechanism. The vent hole 241b corresponds to the “communication portion” in the present invention, and the striker 243 corresponds to the “communication portion opening / closing member” in the present invention.
Note that the ring case 257 is fitted to the inner peripheral portion of the front end side of the cylinder guide 235, and rearward movement is restricted by a retaining ring 259 fixed to the cylinder guide 235.

  Next, a description will be given of a mechanism that absorbs a reaction force caused by rebound generated in the hammer bit 219 during the hammering operation and positioning of the main body 203 with respect to the workpiece when the hammer bit 219 is pressed against the workpiece. As shown in FIGS. 9 and 10, the impact bolt 245 includes a large-diameter portion 245a, small-diameter portions 245b and 245c formed on the front and rear sides in the major axis direction of the large-diameter portion 245a, and a large-diameter portion 245a. And front and rear tapered portions 245d and 245e formed between the front and rear small diameter portions 245b and 245c. The impact bolt 245 is slidable in the major axis direction by the front and rear ring holders 253 and 255, and when the hammer bit 219 is pressed against the workpiece and moves backward, the impact bolt 245 moves backward together with the hammer bit 219. The rear taper portion 245e is configured to contact the inner diameter taper portion 255a of the rear ring holder 255. The rear ring holder 255 corresponds to the “positioning member” in the present invention.

  The rear ring holder 255 is fitted to the inner periphery of the front end of the cylinder guide 235 so as to be slidable in the long axis direction, and is disposed opposite to the front position of the ring case 257 described above. A compression coil spring 251 for absorbing reaction force is disposed between the ring case 257 and the rear ring holder 255. Therefore, when the hammer bit 219 is pressed against the workpiece, the pressing force of the hammer bit 219 against the workpiece is elastically received by the compression coil spring 251 via the impact bolt 245 and the rear ring holder 255. Thus, the main body 103 is positioned with respect to the workpiece. At this time, the compression coil spring 251 is set so that a normal worker has a residual pressure that is equal to or greater than the force with which the hammer bit 219 is pressed against the workpiece. The compression coil spring 251 corresponds to “positioning elastic body” and “coil spring” in the present invention, and the ring case 257 corresponds to “opposing member” in the present invention.

  The outer shape of the rear ring holder 255 is formed in a stepped shape having a large-diameter portion 255b on the front side and a small-diameter portion 255c on the rear side, and the front region in the major axis direction of the compression coil spring 251 is outside the small-diameter portion 255c. They are arranged so as to overlap. The front end of the compression coil spring 251 is in contact with the stepped locking surface 255d between the large diameter portion 255b and the small diameter portion 255c of the rear ring holder 255, and the rear end is in contact with the front surface of the ring case 257. ing. Thereby, the contact location between the compression coil spring 251 and the rear ring holder 255 is set to be a front position relative to the contact location between the impact bolt 245 and the rear ring holder 255.

  Next, the operation of the hammer drill 201 configured as described above will be described. When the drive motor 111 is energized and driven, the rotating body 227 is rotated in the vertical plane via the driven gear 223 engaged with and engaged with the drive gear 221 and the intermediate shaft 225. The moving rod 228 swings. The cylindrical piston 241 is slid linearly by the swing of the swing rod 228. At this time, when the hammer bit 219 is in an unloaded state where it is not pressed against the workpiece and the striker 243 is supplemented by the O-ring 258, the striker 243 is placed at a front position where the vent hole 241b is opened. When the cylindrical piston 241 is moved forward or backward, air in the air chamber 241a is discharged or sucked to the outside through the vent hole 241b, and the hammer bit 119 is prevented from being blown.

  In the load state in which the hammer bit 219 is pressed against the workpiece, as shown in FIG. 8, the striker 243 is pushed backward by the impact bolt 245 pushed backward together with the hammer bit 219, and the vent hole 241b is closed. . For this reason, due to the action of the air spring of the air chamber 241a of the cylindrical piston 241 accompanying the sliding movement of the cylindrical piston 241, the striker 243 linearly moves inside the cylindrical piston 241 and collides with the impact bolt 245. The operating energy is transmitted to the hammer bit 219.

  On the other hand, when the first transmission gear 231 is rotated together with the intermediate shaft 225, the cylinder guide 235 is rotated in the vertical plane via the second transmission gear 233 engaged and engaged with the first transmission gear 231. The tool holder 237 and the hammer bit 219 held by the tool holder 237 are rotated together with the guide 235. Thus, the hammer bit 219 performs a hammer operation in the major axis direction and a drill operation in the circumferential direction, and performs a hammer drill operation (drilling operation) on the workpiece.

  As described above, the hammer drill operation is performed in a load state in which the hammer bit 219 is pressed against the workpiece. The hammer bit 219 that is pushed backward by being pressed against the workpiece causes the impact bolt 245 to move backward. The impact bolt 245 that moves backward is brought into contact with the rear ring holder 255. In this way, the pressing force of the hammer bit 119 against the workpiece by the operator is received in a resilient manner by the compression coil spring 251. As a result, the main body 203 is positioned with respect to the workpiece, and the hammer drilling operation is performed in this state.

  After the hammer bit 219 hits the workpiece, the hammer bit 219 receives a reaction force from the workpiece and rebounds. The force due to the rebound, that is, the reaction force, moves the impact bolt 245 and the rear ring holder 255 backward, and elastically deforms the compression coil spring 251. That is, the reaction force caused by the bounce of the hammer bit 219 is absorbed by the elastic deformation of the compression coil spring 251 and transmission to the main body 203 is reduced. At this time, the rear end surface of the rear ring holder 255 is opposed to the front end surface of the ring case 257 with a predetermined gap, thereby defining the maximum retracted position of the rear ring holder 255. For this reason, the reaction force absorbing action by the compression coil spring 251 is performed within the above gap.

  As described above, in the present embodiment, the reaction force that the hammer bit 219 receives from the workpiece after positioning of the main body 203 with respect to the workpiece and the hammer bit 219 is performed prior to the hammer drilling operation. Since the compression coil spring 251 absorbs the pressure, for example, the spring constant can be set smaller than the configuration in which the reaction force is absorbed by the rubber ring, and the reaction force absorption effect can be enhanced.

  Further, in the present embodiment, a small diameter portion 255c is formed on the rear side of the rear ring holder 255, and the compression coil spring 251 is disposed so as to overlap the small diameter portion 255c. That is, the axially forward region of the compression coil spring 251 is disposed so as to overlap the outside of the rear ring holder 255, and the contact point between the compression coil spring 251 and the rear ring holder 255 is the contact point between the impact bolt 245 and the rear ring holder 255. It is set to the forward position. With such a configuration, it is possible to shorten the length of the hammer drill 201 in the major axis direction while securing a predetermined elastic deformation amount necessary for absorbing the reaction force for the compression coil spring 251.

Next, a modified example of the second embodiment will be described with reference to FIGS. 11 and 12. In the above-described second embodiment, during the hammer drill operation, when the compression coil spring 251 is pushed with an excessive pushing load exceeding the set value and adjacent coils are brought into close contact with each other, a large impact acts on the compression coil spring 251. Then, there is a possibility that the compression coil spring 251 may be damaged, or that the reaction force is directly transmitted to the main body 203 side by the rear ring holder 255 coming into contact with the ring case 257.
Therefore, in this modified example, in view of the above problems, a buffer member 261 is disposed between the rear ring holder 255 and the ring case 257 separately from the compression coil spring 251 so as to absorb the reaction force during the hammer drill operation. did. The buffer member 261 corresponds to a “stopper” in the present invention.

  The buffer member 261 is formed in a ring shape from urethane or rubber, and outside the compression coil spring 251, an annular mounting groove 257a formed on the front surface of the ring case 257 has a predetermined height from the front surface toward the front. It is mounted in a protruding state. The buffer member 261 may be mounted on the rear ring holder 255 side.

  According to the modified example configured as described above, when a large pressing load exceeding the set value is applied to the compression coil spring 251 during the hammer drill operation, the buffer member 261 contacts the rear surface of the rear ring holder 255. This state is shown in FIG. That is, the buffer member 261 can be protected from an impact when the compression coil spring 251 is brought into contact by contacting the rear surface of the rear ring holder 255 in a stage before the compression coil spring 251 is brought into a close contact state. The effect of absorbing the reaction force can be further enhanced by the elastic deformation.

  In the first embodiment described above, the striker 143 controls opening / closing of the vent hole 141b provided in the cylinder 141 with respect to the blanking prevention mechanism for preventing the hammer bit 119 from being blanked in a no-load state. Although described in the case, it is not limited to this. For example, an idling prevention mechanism configured to control opening / closing of the vent hole 141b by moving a valve member formed of a slide sleeve slidably disposed outside the cylinder 141 by the positioning member 151 may be used. In that case, the slide sleeve is normally placed in an open position where the vent hole 141b is opened by being urged by a spring toward the front, and retreats together with the hammer bit 119 when the hammer bit 119 is pressed against the workpiece. The operated impact bolt 145 is moved to the closed position for closing the vent hole 141b via the positioning member 151. The slide sleeve corresponds to the “movable member” in the present invention.

It is a sectional side view showing the whole electric hammer composition concerning a 1st embodiment of the present invention. It is an expanded sectional view showing the principal part of an electric hammer, and shows a no-load state where a hammer bit is not pressed against a work material. It is a plane sectional view showing the principal part of an electric hammer, and shows a load state where a hammer bit was pressed against a work material. It is an expanded sectional view showing the principal part of the electric hammer concerning a modification of a 1st embodiment, and shows a no-load state where a hammer bit is not pressed against a work material. It is a plane sectional view showing the principal part of an electric hammer similarly, and shows a load state where a hammer bit was pressed against a work material. It is a plane sectional view showing the principal part of an electric hammer similarly, and shows a reaction force absorption state. It is a sectional side view which shows the hammer drill which concerns on the 2nd Embodiment of this invention, and shows the capture | acquisition state (empty strike prevention state) of the striker. It is side sectional drawing which similarly shows a hammer drill, and shows the time of an impact. It is an enlarged view of the A section of FIG. It is an enlarged view of the A section of FIG. 8, and shows a reaction force absorption state. It is a principal part enlarged view which shows the example of a change of 2nd Embodiment, and shows the time of an impact. Similarly it is a principal part enlarged view, and shows a reaction force absorption state.

Explanation of symbols

101 Electric hammer (blow tool)
103 Main body (tool body)
105 Motor housing 107 Gear housing 107a Spring receiving surface 108 Cylindrical member 108a Locking surface 109 Hand grip 109a Slide switch 111 Drive motor 113 Motion conversion mechanism 115 Impact element 119 Hammer bit (hammer actuating member)
121 Drive gear 123 Driven gear 125 Crank plate 126 Eccentric shaft 127 Crank arm 128 Connection shaft 129 Piston (Driver)
137 Tool holder 137a Rear end portion 141 Cylinder 141a Air chamber 141b Ventilation hole (communication portion)
143 striker (batter, communication part opening and closing member)
145 Impact bolt (hammer actuating member)
145a Large diameter portion 145b Small diameter portion 145c Tapered portion 151 Positioning member 153 Rubber ring 155 Front metal washer 157 Rear metal washer 158 Retaining ring 159 Coil spring 161 Dynamic vibration absorber 163 Weight 165F, 165R Biasing spring (elastic element, positioning elastic body)
167 Spring receiving member 167a Flange portion 171 Compression coil spring (positioning elastic body)
172 Retaining ring 173 Spring receiving ring 175 Spring receiving member 175a Flange portion 201 Hammer drill (blow tool)
203 Main body (tool body)
205 motor housing 207 gear housing 211 drive motor 213 motion conversion mechanism 214 power transmission mechanism 215 striking element 219 hammer bit (hammer actuating member)
221 Drive gear 223 Driven gear 224 Engagement part 225 Intermediate shaft 226 Bearing 227 Rotating body 228 Swing rod 229 Swing ring 231 First transmission gear 233 Second transmission gear 235 Cylinder guide 237 Tool holder 241 Cylindrical piston 241a Air chamber 241b Ventilation hole (communication part)
243 striker (batter, communication part opening and closing member)
243a Strike part 243b Flange part 245 Impact bolt (hammer actuating member)
245a Large diameter portion 245b Front small diameter portion 245c Rear small diameter portion 245d Front taper portion 245e Rear taper portion 251 Compression coil spring 253 Front ring holder 255 Rear ring holder (positioning member)
255a Inner diameter taper portion 255b Large diameter portion 255c Small diameter portion 255d Locking surface 257 Ring case (opposing member)
257a Mounting groove 258 O-ring 259 Retaining ring 261 Buffer member

Claims (8)

A hammering tool that performs a predetermined hammering operation on a workpiece by a hammering operation in the major axis direction of a hammer operating member,
A tool body;
A cylinder housed in the tool body;
A driver that performs linear motion in the longitudinal direction of the hammer actuating member;
A striker that linearly moves in the longitudinal direction of the hammer operating member in the cylinder;
An air chamber formed between the driver and the striker in the cylinder;
A predetermined hammering operation is performed on the workpiece by causing the hammer actuating linearly via the pressure fluctuation of the air chamber accompanying the linear motion of the driver to strike the hammer actuating member.
At the time of loading when the hammer actuating member is pressed against the work piece and pushed toward the driver side, the hammer actuating member is brought into contact with the hammer actuating member, and at the time of no load when the hammer actuating member is not pushed against the work piece, A positioning member spaced from the hammer actuating member;
When the load is applied, the tool main body is positioned with respect to the workpiece by abutting with the positioning member, and the hammer operating member performs a hammering operation on the workpiece at the positioning position. An elastically deformable positioning elastic body that absorbs a reaction force due to rebound from the workpiece, which is input from the positioning member from
A communication portion for preventing air strikes that communicates the air chamber with the outside,
It is comprised by the said striker arranged inside the said cylinder, or the movable member arrange | positioned outside the said cylinder, and it can move between the closed position which closes the said communication part, and the open position which opens the said communication part In the no-load state, the communication portion is placed in an open position where the communication portion is opened, thereby making it impossible for the air chamber to fluctuate in pressure. In the load state, the communication portion is pushed by the hammer actuating member or the positioning member to close the communication portion. A striking tool comprising: a communication part opening / closing member that enables pressure fluctuation of the air chamber by moving to a closed position. The impact tool according to claim 1,
A striking tool comprising an elastic member that biases the positioning member forwardly away from the striking element. The impact tool according to claim 2,
The striking tool, wherein the positioning elastic body 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. The impact tool according to any one of claims 1 to 3,
A dynamic vibration absorber, and the dynamic vibration absorber has a weight capable of linear motion in a state in which an urging force is applied by an elastic element, and the weight moves in the longitudinal direction of the hammer actuating member. A striking tool configured to perform vibration control during work. The impact tool according to claim 4,
The impact tool, wherein the positioning elastic body is configured by the elastic element as a constituent member of the dynamic vibration absorber. The impact tool according to claim 1,
The positioning member is configured by an annular member that is disposed outside the hammer actuating member and is capable of coming into contact with the outer diameter portion of the hammer actuating member from behind.
On the rear side of the positioning member, an opposing member that faces the positioning member with a predetermined interval is disposed in a state in which rearward movement is restricted by the tool body,
The hitting tool, wherein the positioning elastic body is configured by a coil spring disposed in an intervening manner between the positioning member and the opposing member. The impact tool according to claim 6,
The coil spring is disposed so that an axial front region thereof overlaps the outside of the positioning member, and a front end portion in contact with the positioning member is in front of a contact portion between the hammer operating member and the positioning member. The impact tool characterized by being set to a position. The striking tool according to claim 6 or 7,
One of the positioning member and the opposing member is in contact with the other of the positioning member and the opposing member at the stage before the coil spring reaches a close contact state when absorbing the reaction force due to compression deformation of the coil spring. A striking tool comprising a stopper that is elastically deformed in contact.

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