JP2009061552A - Impact tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an improved technique effective for reducing vibration of an impact tool in the impact tool that linearly drives a tool bit in the longitudinal axial direction by using a swinging mechanism. <P>SOLUTION: The impact tool is provided with the tool bit 119, a tool body part 103, a motor 111, a rotary shaft 125, the swinging mechanism 130, a piston cylinder 141, a striker 143, and an air chamber 141a. A mass body is composed of the piston cylinder 141 and the swinging mechanism 130. An elastic body 153 is arranged between the swinging mechanism 130 and a tool body part side. The elastic body 153 is elastically deformed by the mass body moving backward to accumulate resilient force therein. Kinetic energy generated in the mass body moved forward by the resilient force accumulated in the elastic body 153, is oppositely operated against compressive reaction force acting on the piston cylinder 141 when the striker 143 is hit forward. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vibration control technique for an impact tool in which a tool bit is linearly driven in a long axis direction by a swing mechanism that performs a swing operation.

  In a swash bearing type electric hammer drill that drives a hammer bit using a swash mechanism (oscillation mechanism) in which a swash plate oscillates, for example, GB Patent Publication No. 2154497 is a technique for suppressing vibration generated in the hammer drill during machining operations. It is disclosed in the gazette (patent document 1). The vibration damping mechanism described in the above publication is generated in the main body portion by separating the tool main body portion having the striking mechanism and the handle portion gripped by the operator and connecting the main body portion and the handle portion via an elastic body. This is a technique for reducing the transmission of vibration to the handle part and thereby reducing the vibration.

The main vibration as a vibration suppression target generated in the tool main body during machining operation is a compression reaction force that acts on the piston when the piston compresses air in the air chamber so as to strike the striker forward. According to the vibration control mechanism described in the above publication, when vibration is generated in the tool main body due to the compression reaction force acting on the piston, the elastic body is elastically deformed to reduce transmission of the vibration to the handle. can do. However, the vibration damping mechanism described in the publication still has room for improvement in order to reduce the vibration of the impact tool.
GB Patent Publication No. 2154497

  SUMMARY OF THE INVENTION An object of the present invention is to provide an improved technique that is effective in realizing a low vibration of the impact tool in an impact tool in which a tool bit is driven linearly in the long axis direction by a swing mechanism. .

In order to achieve the above-mentioned object, a preferred embodiment of the impact tool according to the present invention is an impact tool for performing a predetermined machining operation on a workpiece by an impact operation in the long axis direction of a tool bit. A motor housed in the shaft, a rotating shaft that is arranged in parallel to the long axis direction of the tool bit and is driven to rotate by the motor, and a long axis direction of the rotating shaft that is supported by the rotating shaft and based on a rotating operation of the rotating shaft Oscillating mechanism that oscillates at the same time, a cylindrical piston cylinder that is linearly moved in the longitudinal direction of the tool bit by the oscillating operation of the oscillating mechanism, and closed at one end, And a striking element that linearly moves in the longitudinal direction of the tool bit, and an air chamber formed between the piston cylinder and the striking element. Then, the striker, which is linearly moved forward in the tool bit long axis direction through the pressure fluctuation of the air chamber accompanying the linear movement of the piston cylinder in the long axis direction of the tool bit, strikes the tool bit and is machined. A predetermined hammering operation is performed on the material.
The “striking tool” in the present invention is typically an electric hammer that performs hammering work by hammering a hammer bit in a straight line, or a hammer bit that rotates in a circumferential direction while performing a hammering operation. This corresponds to an electric hammer drill for performing a hammer drilling operation. Further, in the present invention, “perform a swinging operation in the major axis direction of the rotating shaft based on the rotating operation of the rotating shaft” typically means that the swinging member is inclined at a predetermined angle with respect to the axis of the rotating shaft. In this state, the rotating shaft is supported so as to be relatively rotatable, and the swinging member swings in the major axis direction of the rotating shaft while rotating relative to the rotating shaft based on the rotation of the rotating shaft.

According to a preferred embodiment of the impact tool of the present invention, the swing mechanism is configured such that the reference position is a position at which the forward movement of the tool bit in the long axis direction is restricted with respect to the rotary shaft. The tool bit is mounted so as to be retractable backward from the tool bit longitudinal direction. In addition, the mass body is configured by the piston cylinder and the swing mechanism portion, and is disposed between the mass body and the tool body portion side behind the mass body, and exerts an urging force in the major axis direction of the rotating shaft. It further has an elastic body. The elastic body is configured such that when the mass body moves backward, the swinging mechanism is elastically deformed to store the elastic force when the swing mechanism is moved rearward from the reference position in the tool bit long axis direction. Then, the elastic force (restoration) of the stored elastic body against the compression reaction force acting on the piston cylinder when the striker is moved (fired) forward in the longitudinal direction of the tool bit by the compression operation of the air chamber. The mass body is moved forward in the tool bit long axis direction by the force), so that the kinetic energy generated in the mass body is applied, thereby canceling the compression reaction force.
Note that the “arrangement mode of the elastic body” in the present invention is a mode in which the elastic body is disposed between the swinging mechanism unit and the tool main body side, or a mode in which the elastic body is disposed between the piston cylinder and the tool main body side. Both are included suitably. Further, “the direction in which the urging force is applied by the elastic body” only needs to include the major axis direction component of the rotating shaft. The “elastic body” in the present invention typically corresponds to a spring, but preferably includes rubber. Further, the “tool body side” in the present invention is a concept including a member that does not move at least in the long axis direction of the hammer bit, and does not indicate only the tool body itself.

  According to the present invention, the force for moving the swing mechanism backward from the reference position, that is, the backward force acting on the swing mechanism is stored as the elastic force of the elastic body, and the stored elastic force is stored. While converting to the forward kinetic energy of the mass body constituted by the piston cylinder and the swing mechanism, the kinetic energy is applied to the compression reaction force applied to the piston cylinder when the striker is moved forward (fired) By acting as a counter force, the compression reaction force is offset. Thereby, it is possible to rationally absorb (attenuate) the compression reaction force applied to the piston cylinder when the striker is driven forward, and the vibration of the impact tool can be reduced. Note that the mass body moved forward by the elastic force of the elastic body is restricted from moving forward in the tool bit long axis direction by the swing mechanism abutting against the tool body at the reference position. Useless movement of the body is prevented.

  According to the further form which concerns on the impact tool of this invention, it arrange | positions between a rocking | swiveling mechanism part and a rotating shaft, and it rolls and contacts in the major axis direction of the said rotating shaft with respect to both a rocking | swiveling mechanism part and a rotating shaft. It has a plurality of rolling members. As the “rolling member” in the present invention, a spherical body or a cylindrical body can be preferably used. According to the present invention, a plurality of rolling members are interposed between the swinging mechanism portion and the rotating shaft, so that the moving operation in the major axis direction of the swinging mechanism portion with respect to the rotating shaft is smoothly performed by the rolling member. Can be made.

  According to the further form which concerns on the impact tool of this invention, between the rocking | fluctuation mechanism part and a rotating shaft, the positioning which hold | maintains the said several rolling member so that the arrangement space | interval of several rolling members may be maintained. It is set as the structure by which the member is arrange | positioned. Note that the “positioning member” in the present invention is typically constituted by a cylindrical member, and the cylindrical member is relative to either the rotating shaft or the swinging mechanism portion in the long axis direction. It is attached so that it can move, and it is attached so that it cannot move relative to the other. Further, the rolling member is typically held by the positioning member by fitting the rolling member into a holding hole penetrating in the radial direction formed in the cylindrical member. According to the present invention, it is possible to always maintain a plurality of rolling members arranged between the swinging mechanism portion and the rotation shaft at a predetermined arrangement interval. The smoothness of the moving operation can be maintained.

  According to the present invention, in an impact tool that drives a tool bit linearly in the long axis direction by a swing mechanism, an improved technique effective in realizing low vibration of the impact tool is provided. became.

  Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. The embodiment of the present invention will be described using an electric hammer drill as an example of an impact tool. FIG. 1 is a side sectional view showing the overall configuration of the hammer drill 101 according to the present embodiment, and shows a no-load state in which the hammer bit 119 is not pressed against the workpiece. As shown in FIG. 1, the hammer drill 101 generally includes a main body 103 that forms an outline of the hammer drill 101, and a hammer bit that is detachably attached to a tip region of the main body 103 via a tool holder 137. 119 is mainly configured. The main body 103 corresponds to the “tool main body” in the present invention, and the hammer bit 119 corresponds to the “tool bit” in the present invention.

  The main body 103 includes a motor housing 105 that houses a drive motor 111, a gear housing 107 that houses a motion conversion mechanism 113, a power transmission mechanism 114, and a striking element 115, and a hand grip 109. The drive motor 111 corresponds to a “motor” in the present invention. The rotation output of the drive motor 111 is appropriately converted into a linear motion by the motion conversion mechanism 113 and then transmitted to the striking element 115, and 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 transmitted to the hammer bit 119 after being appropriately decelerated by the power transmission mechanism 114, and the hammer bit 119 is rotated in the circumferential direction. The drive motor 111 is energized and driven by pulling a trigger 109 a disposed on the handgrip 109. 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 motion conversion mechanism 113 is driven to rotate in the vertical plane by the drive motor 111, the driven gear 123 that meshes and engages with the drive gear 121, and the rotation that rotates together with the driven gear 123 via the intermediate shaft 125. Body 127, rocking ring 129 as a rocking member rocked in the major axis direction of hammer bit 119 by rotation of rotating body 127, and cylindrical piston 141 reciprocating linearly by rocking of rocking ring 129. It is composed mainly of. The intermediate shaft 125 corresponds to the “rotary shaft” in the present invention, and the cylindrical piston 141 corresponds to the “piston cylinder” in the present invention. The intermediate shaft 125 is disposed parallel (horizontally) to the major axis direction of the hammer bit 119, and the outer peripheral surface of the rotating body 127 attached to the intermediate shaft 125 is inclined at a predetermined inclination angle with respect to the axis of the intermediate shaft 125. Is formed. The rocking ring 129 is supported on the inclined outer peripheral surface of the rotating body 127 so as to be relatively rotatable via a bearing 126, and intersects the major axis direction of the hammer bit 119 and the major axis direction in accordance with the rotational operation of the rotating body 127. It is swung in the direction of The oscillating mechanism 130 is constituted by the rotator 127 and the oscillating ring 129 supported by the rotator 127 via a bearing 126 so as to be relatively rotatable, and the oscillating mechanism 130 is the “oscillator mechanism” in the present invention. Corresponding to

  In the upper end portion region of the rocking ring 129, a rocking rod 128 that protrudes integrally upward (radially) is provided, and the rocking rod 128 is located at the rear end of the cylindrical piston 141. 141 is engaged in a loose-fitting manner with an engaging portion 124 provided so as to be rotatable around an axis intersecting with the long-axis north port 141 (moving direction). Thereby, the direction (long axis direction of the rocking rod 128) intersecting the long axis direction of the cylindrical piston 141 between the rocking ring 129 and the cylindrical piston 141 accompanying the rocking motion of the rocking ring 129. Interference is absorbed. The cylindrical piston 141 is formed in a cylindrical shape with one end (rear end) closed. The cylindrical piston 141 is slidably disposed in the cylinder 135 and is driven by the swinging motion of the swinging ring 129 (the component in the long axis direction of the hammer bit 119) to perform a linear motion along the cylinder 135. Do. The “mass body” in the present invention is constituted by the swing mechanism 130 and the cylindrical piston 141.

  The striking element 115 includes a striker 143 slidably disposed in a cylindrical hole of the cylindrical piston 141, and an intermediate element that is slidably disposed on the tool holder 137 and transmits operating energy of the striker 143 to the hammer bit 119. As an impact bolt 145 as a main constituent. The striker 143 corresponds to the “batter” in the present invention. The striker 143 is driven (fired) through the pressure fluctuation (air spring) of the air chamber 141a of the cylindrical piston 141 accompanying the sliding operation of the cylindrical piston 141, and slides into the cylindrical tool holder 137. The impact bolt 145 that is freely arranged collides (hits), and the impact force is transmitted to the hammer bit 119 via the impact bolt 145. A bit striking mechanism is configured by the cylindrical piston 141, the air chamber 141a, the striker 143, and the impact bolt 145.

  The power transmission mechanism 114 includes a first transmission gear 131 that is rotationally driven in the vertical plane from the drive motor 111 via the drive gear 121 and the intermediate shaft 125, and a second transmission gear that meshes with and engages with the first transmission gear 131. 133, which is mainly composed of a cylinder 135 that rotates together with the second transmission gear 133. The rotational driving force of the cylinder 135 is transmitted to the tool holder 137 and further transmitted to the hammer bit 119 held by the tool holder 137.

  Next, regarding the vibration control mechanism 151 provided to absorb the compression reaction force acting on the cylindrical piston 141 when the striker 143 is moved forward (fired) during the machining operation of the hammer drill 101, FIGS. Will be described with reference to FIG. FIG. 2 shows a reversing operation in which the moving direction of the cylindrical piston 141 is switched from a backward operation to a forward operation, that is, a swash switching, and FIG. 3 shows a maximum compression of the air chamber 141a, that is, a piston-striker maximum compression. . 4 is a cross-sectional view taken along line AA in FIG.

  The vibration damping mechanism 151 according to the present embodiment is mainly configured by a coil spring 153 that urges the swing mechanism 130 to move backward with respect to the intermediate shaft 125. A rotating body 127 that is one of the constituent members of the swing mechanism 130 is attached to the intermediate shaft 125 so as to be relatively movable in the axial direction while rotating together with the intermediate shaft 125. The coil spring 153 is disposed between the rotating body 127 and the driven gear 123 positioned behind the rotating body 127 and acts on the rotating body 127 in the forward direction. As a result, the swing mechanism 130 allows the first transmission fixed to the intermediate shaft 125 as shown in FIG. 1 when there is no load when the hammer bit 119 is not pressed against the workpiece, that is, when the hammer drill 101 is not in operation. It is held at a position where it contacts the rear end of the gear 131. Thus, in the swing mechanism 130, the foremost position at which forward movement is restricted by contact with the first transmission gear 131 is set as the reference position at the time of no load, and the backward movement operation from the reference position is performed. Is allowed. The first transmission gear 131 corresponds to the “tool main body side” in the present invention.

  A plurality of steel balls 155 are interposed between the rotating body 127 and the intermediate shaft 125 in the swing mechanism 130. The steel ball 155 corresponds to the “rolling member” in the present invention. On the inner peripheral surface of the shaft hole of the rotating body 127 and the outer peripheral surface of the intermediate shaft 125, a plurality of rows extending in the major axis direction, in this embodiment, four rows of grooves 127a and 125a as shown in FIG. In this embodiment, a plurality of steel balls 155 roll in each of the grooves 127a and 125a in each row as shown in FIG. 2 and FIG. Arranged freely. Thereby, the rotating body 127 is connected to the intermediate shaft 125 so as to be relatively movable in the major axis direction while rotating together with the intermediate shaft 125 via the steel ball 155. By connecting the rotating body 127 and the intermediate shaft 125 through the steel balls 155 in this way, the backward movement operation of the swing mechanism 130 from the reference position is smoothed.

  Further, the plurality of steel balls 155 are held by a cylindrical holding sleeve 157 arranged between the rotating body 127 and the intermediate shaft 125 so as to maintain a mutual arrangement interval. The holding sleeve 157 corresponds to the “positioning member” in the present invention. The holding sleeve 157 has a predetermined number of holding holes 159 penetrating in the radial direction, and holds one steel ball 155 in each holding hole 159 one by one. The holding sleeve 157 is formed in a cylindrical shape having a flange portion 157a projecting to the outer diameter side at one end (rear end) in the long axis direction, and is fitted into the intermediate shaft 125 in a loosely fitting manner. Relative movement in the major axis direction with respect to the intermediate shaft 125 is allowed, and the rotating body 127 is fixed by, for example, press-fitting into the shaft hole. As a result, the plurality of steel balls 155 can roll in the grooves 127a and 125a while maintaining a predetermined arrangement interval. The flange portion 157a of the holding sleeve 157 is in contact with the axial rear end of the rotating body 127, and one end of the coil spring 153 is in contact with the end surface of the flange portion 157a. The other end of the coil spring 153 in the axial direction is partly fitted into a housing recess 123a formed on the front side surface of the driven gear 123 so that the movement in the radial direction is restricted, and the expansion and contraction operation is stabilized. Is planned. The housing recess 123a of the driven gear 123 corresponds to the “tool body side” in the present invention.

  Next, the operation of the hammer drill 201 configured as described above will be described. When the drive motor 111 is energized, the drive gear 121 rotates in the vertical plane by the rotation output. Then, the rotating body 127 is rotated in the vertical plane via the driven gear 123 engaged with and engaged with the drive gear 121 and the intermediate shaft 125, whereby the swing ring 129 and the swing rod 128 are moved in the front-rear direction (hammer). It swings in the long axis direction of the bit 119. The cylindrical piston 141 slides linearly by the swing of the swing rod 128, and the striker 143 moves linearly in the cylindrical piston 141 by the action of the air spring of the air chamber 141a of the cylindrical piston 141. By colliding with the impact bolt 145, the operating energy is transmitted to the hammer bit 119.

  On the other hand, when the first transmission gear 131 is rotated together with the intermediate shaft 125, the cylinder 135 is rotated in the vertical plane via the second transmission gear 133 engaged and engaged with the first transmission gear 131. At the same time, the tool holder 137 and the hammer bit 119 held by the tool holder 137 are rotated together. Thus, the hammer bit 119 performs a hammering operation in the major axis direction and a drilling operation in the circumferential direction to perform a machining operation (drilling operation) on the workpiece.

In the above machining operation, as shown in FIG. 2, when the cylindrical piston 141 moving backward (right side in FIG. 2) changes the moving direction forward (when swash is turned back), the coil spring 153 is A backward force (hereinafter, this force is referred to as a reaction force) due to the turn-back is applied. That is, when the movement direction of the cylindrical piston 141 switches from the rear to the front, the rotating body 127 that is the swing fulcrum side member of the swing mechanism 130 is opposite to the moving direction after the tubular piston 141 is reversed. A force in the direction (backward), that is, a counter-reaction force is generated. Then, due to this reaction force, the rotating body 127 of the swinging mechanism 130 moves rearward from the reference position along the intermediate shaft 125, whereby the coil spring 153 is pushed and elastically deformed by the rotating body 127 moving backward. Save resilience. In FIG. 2, an arrow P indicates a swash turn-back direction, and an arrow F indicates a direction in which a reaction force is applied.
As described above, the coil spring 153 is configured such that the mass body constituted by the cylindrical piston 141 and the swing mechanism 130 is retracted, specifically, the rotating body 127 as the swing fulcrum side member of the swing mechanism 130 is moved from the reference position. When moving backward, it is pushed by the rotating body 127 to store the resilience.

  The air in the air chamber 141a is compressed by the forward movement of the cylindrical piston 141 whose movement direction is reversed (and the movement of the striker 143 rearward), and the striker 143 moves forward through the maximum compression state of the air chamber 141a. When moved (fired), a compression reaction force acts on the cylindrical piston 141. At this time, the elastic force stored in the coil spring 153 by the inertial force moves the swing mechanism 130 and the cylindrical piston 141 as the mass body forward, and the kinetic energy generated in the mass body is It acts as a counter force so as to cancel the compression reaction force. That is, the elastic force of the coil spring 153 changes so as to move the swing mechanism 130 and the cylindrical piston 141 as mass bodies so as to push them forward, whereby the swing mechanism 130 and the cylindrical piston 141 are countered. Acts as a weight against the compression reaction force. This state is shown in FIG. In FIG. 3, the arrow W indicates the direction of counter force action.

  As described above, according to this embodiment, the spring force is stored in the coil spring 153 using the inertial force based on the backward movement of the cylindrical piston 141, and the spring force of the coil spring 153 is reduced. The compression reaction force is offset by acting as a counter force against the compression reaction force applied to the cylindrical piston 141 when the striker 143 is driven forward. As a result, it is possible to rationally absorb (attenuate) the compression reaction force applied to the cylindrical piston 141 when the striker 143 is driven forward, and the vibration of the main body 103 can be reduced.

  In addition, in the forward movement operation along the intermediate shaft 125 of the swing mechanism 130 and the cylindrical piston 141 acting as a counterweight, the rotating body 127 of the swing mechanism 130 comes into contact with the first transmission gear 131 at the front position. Is blocked. That is, the swing mechanism 130 and the cylindrical piston 141 after acting as the counterweight are held at the reference position defined by the first transmission gear 131 until receiving the next swash-turning reaction force.

  In the present embodiment, the rotating body 127 in the swing mechanism 130 is connected to the intermediate shaft 125 via the steel ball 155 so as to be capable of relative movement in the long axis direction while rotating together with the intermediate shaft 125. The configuration was as follows. For this reason, the movement in the major axis direction of the intermediate shaft 125 of the swing mechanism 130 and the cylindrical piston 141 becomes a relative movement by rolling contact via the steel ball 155, and for example, sliding by sliding contact such as spline fitting. Compared with the system, there is less frictional resistance and the smoothness of the moving operation can be improved.

  In addition, according to the present embodiment, the holding sleeve 157 as a positioning member is interposed between the rotating body 127 and the intermediate shaft 125, thereby maintaining the arrangement interval between the plurality of steel balls 155. For this reason, the steel balls 155 are not shifted to one of the axial directions of the grooves 127a and 125a with the movement of the rotating body 127 in the major axis direction, and are always held at a predetermined arrangement interval. As a result, it is possible to continue the smooth movement of the rotating body 127 in the major axis direction by the steel ball 155.

  In the above-described embodiment, the swing ring 129 of the swing mechanism 130 is supported by the intermediate shaft 125 so as to be relatively rotatable at a predetermined inclination angle, and the axial direction of the intermediate shaft 125 is based on the rotation of the intermediate shaft 125. However, the present invention is not limited to this. That is, the oscillating ring is a swash plate, and the swash plate is attached so as to rotate integrally with the intermediate shaft while being inclined at a predetermined inclination angle with respect to the axis of the intermediate shaft. You may employ | adopt for the rocking | swiveling mechanism of the structure which performs rocking | fluctuation operation | movement to an axial direction, rotating with an intermediate shaft. In the above-described embodiment, the hammer drill 101 is described as an example of the striking tool. However, the hammer drill 101 is not limited to the hammer drill 101 and can be applied to a hammer that performs only a hammer operation.

  In the present embodiment, the coil spring 153 is disposed between the rotating body 127 of the swing mechanism 130 and the driven gear 123. However, the coil spring 153 is disposed between the cylindrical piston 141 and the gear housing 107, or The cylindrical piston 141 and the cylinder 135 may be disposed. Further, in the present embodiment, the holding sleeve 157 as a positioning member is fixed to the rotating body 127 side and fitted to the intermediate shaft 125 in a loose fitting manner, but is fitted to the rotating body 127 in a loose fitting manner, You may change to the structure fixed to the intermediate shaft 125 side. Moreover, you may change the steel ball 155 as a rolling member into a cylindrical body (roller), for example.

It is a sectional side view showing the whole composition of the electric hammer drill concerning the embodiment of the present invention, and shows the time of no load in which the hammer bit is not pressed against a work material. It is an expanded sectional view of the principal part, and shows the time of the reversal operation in which the direction of movement of the cylindrical piston switches from the backward movement to the forward movement, that is, the time of swash switching. It is an expanded sectional view of the principal part, and shows the time of maximum compression of an air chamber, ie, the time of piston-striker maximum compression. FIG. 4 is a sectional view taken along line AA in FIG. 3.

Explanation of symbols

101 Hammer drill (blow tool)
103 Body (Tool body)
105 Motor housing 107 Gear housing 109 Hand grip 109a Trigger 111 Drive motor 113 Motion conversion mechanism 114 Power transmission mechanism 115 Impact element 119 Hammer bit (tool bit)
121 Drive gear 123 Driven gear 123a Housing recess (tool body side)
124 engaging portion 125 intermediate shaft (rotating shaft)
125a groove 126 bearing 127 rotating body 127a groove 128 rocking rod 129 rocking ring 130 rocking mechanism (rocking mechanism)
131 1st transmission gear (tool body side)
133 Second transmission gear 135 Cylinder 137 Tool holder 141 Cylindrical piston (piston cylinder)
141a Air chamber 143 Strike (batter)
145 Impact bolt 151 Damping mechanism 153 Coil spring (elastic body)
155 Steel ball (rolling member)
157 Holding sleeve (positioning member)
157a Flange portion 159 Holding hole

Claims (3)

A striking tool that performs a predetermined processing operation on a workpiece by a striking motion forward of the tool bit in the long axis direction,
A tool body,
A motor housed in the tool body,
A rotating shaft that is arranged in parallel with the long axis direction of the tool bit and is driven to rotate by the motor;
A swing mechanism that is supported by the rotary shaft and swings in the major axis direction of the rotary shaft based on the rotary operation of the rotary shaft;
A cylindrical piston cylinder that is linearly moved in the long axis direction of the tool bit by the swinging motion of the swinging mechanism portion and closed at one end;
A striker that linearly moves in the long axis direction of the tool bit within the cylindrical hole of the piston cylinder;
An air chamber formed between the piston cylinder and the striker,
The striking element that is linearly moved forward in the tool bit long axis direction through pressure fluctuations in the air chamber due to linear movement of the piston cylinder in the tool bit long axis direction forward strikes the tool bit. It is configured so that a predetermined hammering operation is performed on the workpiece,
The swing mechanism is configured such that the tool bit length from the reference position is a reference position where a position in which the movement of the tool bit in the long axis direction is restricted by contacting the tool main body side with respect to the rotating shaft is defined as a reference position. It is mounted so that it can move backward in the axial direction,
A mass body is constituted by the piston cylinder and the swing mechanism,
In the rear of the mass body, the elastic body is further disposed between the mass body and the tool main body portion side, and exerts an urging force in the major axis direction of the rotating shaft,
The elastic body is configured such that when the mass body moves backward, the swinging mechanism is elastically deformed when the tool bit moves in the longitudinal direction of the tool bit from the reference position to the rear to store the elastic force. ,
The compression force of the stored elastic body against the compression reaction force acting on the piston cylinder when the striker is moved forward in the long axis direction of the tool bit by the compression operation of the air chamber. A striking tool characterized in that the mass body is moved forward in the longitudinal direction of the tool bit to cause kinetic energy generated in the mass body to act, thereby canceling out the compression reaction force. The impact tool according to claim 1,
A plurality of rolling members arranged between the swinging mechanism portion and the rotating shaft and in rolling contact with both the swinging mechanism portion and the rotating shaft in the major axis direction of the rotating shaft. Blow tool. The impact tool according to claim 2,
A positioning member for holding the plurality of rolling members is disposed between the swinging mechanism portion and the rotating shaft so as to maintain the spacing between the plurality of rolling members. Blow tool.

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