JP2013010147A - Drilling tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drilling tool capable of obtaining stable hammering operation.SOLUTION: The drilling tool includes: a hammering mechanism 4 which converts a rotating force outputted from a driving section to a hammering force and transmits the hammering force to a tip tool 10; and a rotation transmitting mechanism 5 which transmits the rotating force to the tip tool 10. The hammering mechanism 4 includes: a crank 42 driven by the driving section; a piston 47 disposed in a cylinder 43 so as to be reciprocated by the crank 42; and a hammer 48 which transmits the reciprocating operation of the piston 47 as the hammering force to the tip tool 10. A weight 6 is installed in the cylinder 43 freely to concentrically rotate with the cylinder 43 and freely to move in the axial direction, and an engagement part 52B engaged with the weight 6 is fixed to the cylinder so as to concentrically and integrally rotate with the cylinder. The weight part 6 is configured to be engaged with the engagement part 52B accompanied by the movement of the tip tool 10 toward one side in the axial direction.

Description

  The present invention relates to a drilling tool, and more particularly to a drilling tool that drives a tip tool with a striking force and a rotational force to perform drilling.

  As shown in Japanese Patent Application Laid-Open No. 2004-133620, a punching tool striking mechanism includes a piston that is reciprocated by a crank that converts the rotational force of the motor into a reciprocating motion, and is disposed in the cylinder so as to be reciprocally movable. A configuration is known that includes a striking element that transmits a reciprocating motion of a piston via an air chamber in a cylinder and transmits a striking force to a tip tool. In the drilling tool of this configuration, the transition from the no-load state to the loaded state, that is, by pressing the tip tool against the work material, the striker moves to the anti-tip tool side (piston side), and the piston in the cylinder The pressure of the air chamber formed between the striking element and the striking element is increased, and the striking force is transmitted to the tip tool through the striking element by the pressure fluctuation of the air chamber due to the reciprocation of the piston.

  The piston receives a reaction when the air chamber is compressed, and the load generated by the reaction is transmitted to the motor via the crank, gear, etc., and the rotational speed of the motor is reduced. In other words, a decrease in the rotational speed of the motor is a phenomenon resulting from the transition to a load state in which a striking operation is performed. In general, the rotational speed of a motor in a loaded state is a numerical value lower than that in a no-load state. Is shown. In addition, the rotation speed decreases in the load state and converges to a constant rotation speed according to the load condition, which means that the motor output characteristics, cylinder, piston, striker shape, stroke amount, etc. The converged rotation speed becomes a rotation speed suitable for the load state.

Japanese Patent No. 4556180

  Since the rotation speed in the no-load state is higher than the constant rotation speed in accordance with the above-described load state, when the transition from the no-load state to the load state, the striker cannot follow the piston phase change, Defects may occur.

  In particular, when the pressure drop inside the drilling tool main body occurs, the hitting failure is remarkably generated. This pressure drop means that after the drilling tool is used, the temperature of the main body, which has become high, drops to room temperature, and the pressure inside the striking mechanism decreases accordingly. It means that the pressure inside the striking mechanism is negative compared to before use of the main body because air has flowed out. When the main body is used in this negative pressure state, the amplitude of the reciprocating motion of the striker is reduced due to a decrease in the compression force of the air chamber, and the striker returns without going to the strike point, or the velocity at the strike point increases. Since it is small and the rebounding speed is small, the amplitude energy of the striker is not amplified, and the strike force is remarkably reduced, or the strike failure does not shift to the strike action state.

  In addition, the lower the reciprocating speed of the piston, the longer the time from when the piston pulls the striker through the air chamber until the piston phase changes and the air chamber is compressed and the striker is pushed out. Since the amplitude of the child increases, the condition for shifting to the striking motion is advantageous. Therefore, an object of this invention is to provide the drilling tool which can obtain the stable striking operation | movement.

  In order to solve the above problems, the present invention provides a drive unit that outputs a rotational force, an impact mechanism unit that converts the rotational force into the impact force and transmits the impact force to a tip tool, and the rotational force. A rotation transmission mechanism portion that transmits to the tip tool, and the striking mechanism portion is driven by the driving portion to reciprocate, and the piston is interposed between the piston and the tip tool. A striking element that transmits reciprocating motion to the tip tool as a striking force, and the piston is inserted from one axial end side so that the piston and the striking element are slidably incorporated in the axial direction, and the piston An air chamber sealed between the striking elements, and a cylinder portion mounted on the other end in the axial direction so that the tip tool can slide in the axial direction and rotate integrally. The rotation transmission mechanism is driven by the drive unit and A gear mechanism that engages with the portion and rotates the cylinder portion, and is provided with a weight portion that is movable in the axial direction with respect to the cylinder portion, and the weight portion is one side in the axial direction of the tip tool. A drilling tool configured to be able to come into contact with the gear mechanism is provided.

  According to such a configuration, when the tip tool comes into contact with the work material, that is, when the load is changed from the no-load state to the load state, the weight portion engages with the cylinder portion, so that the load acting on the cylinder portion increases. . Since the cylinder part is connected to the drive part by the rotation transmission mechanism part, the load acting on the drive part also increases. Due to this increase in load, the rotational speed of the drive unit decreases, and the rotational speed at which the striker can easily follow the piston in the loaded state can be made. By synchronizing the striker with the operation of the piston, a stable impact operation is obtained. be able to.

  In the drilling tool configured as described above, the weight portion is engageable with the gear mechanism, is located on the other axial side of the gear mechanism and is rotatably mounted on the cylinder portion, An operation unit that is located on the other side in the axial direction and is movable in the axial direction with respect to the cylinder unit, and immovable in the circumferential direction around the axis of the cylinder unit, and the operation unit includes the operation unit It is preferable that the weight is engaged with the gear mechanism by moving to the one side in the axial direction as the tip tool moves to the one side in the axial direction.

  According to such a configuration, the weight portion can be configured to be separated into a weight that engages the gear mechanism and an operation portion that engages the weight, and the weight portion can be used as the engagement portion with a simple configuration. Can be engaged.

  The housing further includes a housing for rotatably supporting the cylinder portion around the axis of the cylinder portion, and the weight portion engages with the weight portion in a state where the weight portion is not engaged with the gear mechanism. It is preferable to have a locking part.

  According to such a configuration, when the weight portion is not engaged with the gear mechanism, the weight portion engages with the locking portion, so that it is possible to suppress the play of the weight portion in the no-load state. .

  The weight portion is preferably provided with an engaged portion that engages with the gear mechanism, and the engaged portion and the gear mechanism are preferably configured in a gear shape that meshes with each other.

  According to such a configuration, the gear mechanism and the weight portion can be easily engaged.

  In order to solve the above problems, a drive unit that outputs a rotational force, a piston that is driven by the drive unit to reciprocate, a striker that reaches the reciprocation of the piston, and the piston and the striker A cylinder portion slidably built in a direction, and a gear mechanism that is driven by the drive portion and engages with the cylinder portion to rotate the cylinder portion. A weight part that is movable in the axial direction is provided, and when the tip tool is pressed against a work material, the weight moves, and a drilling tool that contacts a part of the rotation transmission mechanism part is provided.

  According to the drilling tool of the present invention, a stable hitting operation can be obtained.

Side surface sectional drawing (no load state) of the drilling tool which concerns on embodiment of this invention. 1 is a detailed cross-sectional view (no load state) of a drilling tool according to an embodiment of the present invention. The detailed sectional view (load state) of the drilling tool concerning an embodiment of the invention. The graph which shows the relationship between the rotation speed of a drive part, and the load concerning a drive part.

  Hereinafter, a drilling tool according to an embodiment of the present invention will be described with reference to FIGS. 1 to 4. A hammer drill 1 which is a striking tool shown in FIG. 1 is a tool which applies a striking force and a rotational force to a mounted tip tool 10 to perform drilling / hanging or the like by a tip portion of the tip tool 10. The motor 3, the striking mechanism 4, the rotation transmission mechanism 5, and the weight 6 are provided, and the tip tool 10 is held so as not to fall off by a tip tool holding portion 45 described later. In the following description, the front / rear direction is defined with the front end side of the front end tool 10 as the front side.

  The housing 2 mainly includes a motor housing 21, a handle 22, a gear cover 23, and a cylinder case 24. The motor housing 21 incorporates the motor 3 and the like inside. The handle 22 is provided on the rear side of the motor housing 21 and includes a trigger 22A for controlling the rotation of the motor 3 and a power cord 22B connected to an external power source. The gear cover 23 is provided on the motor housing 21 so as to cover an output shaft portion 31 (to be described later) of the motor 3. As shown in FIG. 2, the cylinder case 24 has a cylindrical shape, and is disposed in front of the gear cover 23 so that the axial direction of the cylinder coincides with the front-rear direction. Bearings 24 </ b> A and 24 </ b> B that support a later-described cylinder 43 </ b> A so as to be rotatable around a rotation axis extending in the front-rear direction are arranged side by side in the cylinder case 24. Further, in the cylinder case 24, a cylindrical rotation locking member 24C is provided behind the front bearing 24A so that the axial direction of the cylinder coincides with the front-rear direction. A locking portion 24D having an internal gear shape having a rotation axis of a cylinder 43A described later as a central axis is provided on the inner surface of the cylinder and the rear end position of the rotation locking member 24C.

  In these housings 2, a seal material is disposed at each joint portion, and in particular, the cylinder case 24 and the gear cover 23 are configured so that the inside thereof can be kept airtight.

  As shown in FIG. 1, the motor 3 as a drive unit has an output shaft portion 31 that outputs a rotational force, and is located in the motor housing 21 and the output shaft portion 31 is located in the gear cover 23. The axial direction of the output shaft portion 31 is disposed so as to be orthogonal to the front-rear direction. The output shaft portion 31 is supported in the motor housing 21 by a bearing 33, and a pinion gear 31 </ b> A is provided at the tip of the output shaft portion 31. A fan 32 for cooling the motor 3 is mounted on the base end portion of the output shaft portion 31 so as to rotate coaxially and integrally.

  As shown in FIG. 2, the striking mechanism unit 4 mainly includes a gear unit 41, a crank unit 42, a cylinder unit 43, and a striking unit 46, and converts rotational motion into reciprocating motion, The reciprocating motion is transmitted to the tip tool 10 as an impact force. The gear portion 41 is disposed with a shaft center parallel to the shaft center of the pinion gear 31A behind the pinion gear 31A, and is composed of a flat gear that is connected to the crank portion 42 and meshes with the pinion gear 31A. 41B is rotatably supported by the gear cover 23.

  The crank part 42 includes a crank 42A and a connecting rod 42B. The crank 42 </ b> A is configured to rotate coaxially with the gear portion 41 and is disposed at a rear position of the cylinder case 24. The connecting rod 42B has a front end disposed in the cylinder case 24 and a rear end rotatably attached to a crank pin of the crank 42A. By rotating the crank 42A, the connecting rod 42B moves back and forth to convert the rotary motion transmitted from the motor 3 into a reciprocating motion.

  The cylinder part 43 is mainly composed of a cylinder 43A. The cylinder 43A has a cylindrical shape, is rotatably supported in the cylinder case 24 by bearings 24A and 24B, and is disposed so that the front-rear direction and the axial direction coincide with each other. The front end of the connecting rod 42B is inserted from the end side. In the cylinder 43A, a pair of long holes 43b and 43b are formed at positions rearward of the bearing 24A and extending in the front-rear direction through the cylinder, and an air hole 43c penetrating the cylinder is formed on the front side of the bearing 24B. Is formed. The air hole 43c is disposed at a position where the air chamber 43d, which will be described later, communicates with the outside of the cylinder 43A immediately before the impact member 48, which will be described later, moves forward and collides with the intermediate member 49, which will be described later. A rib 43B extending in a series around the circumference is provided on the outer circumference of the cylinder 43A and behind the air hole 43c.

  In the cylinder 43A, a later-described intermediate member 49 is inserted into a ring-shaped portion 44 that holds the intermediate member 49 so as to be slidable back and forth, and partitions the cylinder 43A while maintaining airtightness in the front and rear of the intermediate member 49. Is provided. In the cylinder 43A, an air chamber 43d is defined between a piston 47 and a striker 48, which will be described later, and the air chamber 43d can communicate with the air hole 43c according to the front and rear positions of the striker 48, which will be described later. It is.

  In the cylinder 43A, a tip tool holding portion 45 is provided at the front end which is the other end side in the axial direction. The tip tool holding portion 45 can be urged so as to protrude into the cylinder 45A and the balls 45A respectively inserted into a plurality of through holes 43a formed so as to penetrate inside and outside the cylinder at the front end of the cylinder 43A. The sleeve 45B and a spring 45C that abuts the cylinder case 24 and urges the sleeve 45B forward. A held portion 10A (described later) is inserted into a cylinder located at the front end of the cylinder 43A. The tip tool 10 is held.

  The striking part 46 is mainly composed of a piston 47, a striking element 48, and an intermediate element 49. The piston 47 is disposed in the inner space of the cylinder 43A at the rear end position of the cylinder 43A so as to be slidable back and forth with respect to the cylinder 43A so that no gap is formed between the piston 47 and the peripheral wall of the cylinder 43A. The front end of the connecting rod 42B is connected to the rear end of the piston 47 via a piston pin 47B. Therefore, the piston 47 moves back and forth within the cylinder 43A in accordance with the back and forth movement of the connecting rod 42B. A ring-shaped O-ring 47 </ b> A is fitted at a location where the piston 47 comes into contact with the inner peripheral surface of the cylinder 43 </ b> A to maintain the airtightness before and after the piston 47.

  The striker 48 is disposed in the cylinder 43A so as to be slidable with respect to the cylinder 43A at a certain distance from the piston 47 so as to define an air chamber 43d in front of the piston 47 in the cylinder 43A. An air chamber 43 d is defined between the striker 48 and the piston 47. Since no gap is formed between the striker 48 and the peripheral wall of the cylinder 43 </ b> A and an air chamber 43 d is formed between the striker 48 and the piston 47, the air is moved in accordance with the longitudinal movement of the piston 47. A pressure change occurs in the chamber 43d, and the striker 48 also moves back and forth following this pressure change. A ring-shaped O-ring 48 </ b> A is fitted at a location where the striker 48 comes into contact with the inner peripheral surface of the cylinder 43 </ b> A to maintain the airtightness before and after the striker 48.

  The intermediate member 49 is disposed on the front side of the striker 48, and the vicinity of the front end is slidable with respect to the cylinder 43A, and is surrounded by the partition portion 44 near the center, and the front end is attached to the tip tool holding portion 45. The rear end of the attached tip tool 10 can be brought into contact with the rear end, and the rear end can be brought into contact with the front end of the striker 48. A ring-shaped O-ring 49A is fitted in a portion of the meson 49 that contacts the inner peripheral surface of the cylinder 43A, and the O-ring 49A and the partitioning portion 44 maintain the airtightness before and after the meson 49. Further, in the intermediate element 49, the rear end portion 49B is configured to have a smaller diameter than other portions, and a step 49C is provided between the rear end portion 49B and the other portions.

  The rotation transmission mechanism unit 5 is mainly composed of a gear mechanism including a drive unit side gear unit 51 and a spindle side gear unit 52. The drive portion side gear portion 51 is disposed in front of the pinion gear 31A with a shaft center parallel to the shaft center of the pinion gear 31A, and a crank gear 51A that meshes with the pinion gear 31A and a shaft that rotates coaxially with the flat gear 51A. It comprises a bevel gear 51B connected to the portion 42 and positioned near the cylinder 43A, and is rotatably supported by the gear cover 23 by a bearing 51C and a bearing 51D.

  The spindle side gear portion 52 is formed in a cylindrical shape with both ends penetrating therethrough, and is provided around the rib 43B of the cylinder 43A. The spindle side gear portion 52 is fixed to the cylinder 43A via the key 53 so as to rotate coaxially therewith. A bevel gear 52A that meshes with the bevel gear 51B is provided at the rear end of the spindle side gear portion 52, and an engagement portion 52B that can be engaged with the weight portion 6 is provided at the front end. The engaging portion 52B is configured in a spur gear shape having the axis of the cylinder 43A as a rotation axis.

  The weight part 6 mainly includes a weight 61, a spring 62, and an operation part 63. The weight 61 is made of a high-density metal such as a steel material, is formed in a cylindrical shape with both ends penetrating, and is disposed in front of the rib 43B, and can be engaged with the engaging portion 52B at the rear end. A portion 61A is provided, and a locked portion 61B that can be engaged with the locking portion 24D is provided at the front end. The engaged portion 61A has an internal gear shape with the rotation axis of the cylinder 43A as the central axis, and the engaged portion 61B has a spur gear shape with the rotation axis of the cylinder 43A as the central axis. Yes.

  The spring 62 takes a reaction force on the rib 43B and biases the weight 61 forward. A washer 62A for reducing rotational friction between the spring 62 and the weight 61 is interposed between the spring 62 and the weight 61. When the spring 62 biases the weight 61 forward, the weight 61 comes into contact with the rotation locking member 24C and the locked portion 61B is locked to the locking portion 24D unless the weight 61 is biased backward. The Since the rotation locking member 24C is integral with the cylinder case 24, the weight 61 does not rotate integrally with the cylinder 43A in this state. Further, since the weight 61 is locked to the rotation locking member 24 </ b> C, the weight 61 is suppressed from moving in the cylinder case 24, and the occurrence of backlash is suppressed.

  The operation unit 63 includes an annular member 64, a pin 65, and a sleeve 66. The annular member 64 has an inner diameter that is substantially the same as the outer shape of the rear end portion 49B, and is attached to the rear end portion 49B. Since there is a step 49C in front of the rear end portion 49B, the annular member 64 moves rearward together with the intermediate element 49 by the step 49C. A pair of pins 65 are provided corresponding to the pair of long holes 43b, 43b, and are fixed to the annular member 64 so as to protrude from the pair of long holes 43b, 43b to the outside of the cylinder 43A. Yes. The sleeve 66 is formed in an annular shape so as to be mounted on the cylinder 43A, contacts the weight 61 at the rear end, and engages with the pin 65 at the front end. The sleeve 66 is only in contact with the weight 61 in the front-rear direction, and the weight 61 is not particularly restricted in the circumferential direction and the radial direction of the cylinder 43A. In the operation part 63, when the annular member 64 moves backward, the pin 65 and the sleeve 66 also move backward. Since the weight 61 is disposed behind the sleeve 66, the weight 61 also moves rearward as the annular member 64 moves rearward, and the locked portion 61B is detached from the locking portion 24D. The engaged portion 61A engages with the engaging portion 52B. In this state, the weight 61 rotates coaxially with the cylinder 43A.

  The tip tool 10 has a drill portion at a front end (not shown) and a held portion 10 </ b> A whose rear end is held by a tip tool holding portion 45. The held portion 10A is inserted into the cylinder at the front end of the cylinder 43A and is configured to be slidable in the front-rear direction. A groove 10a extending in the front-rear direction in which the ball 45A is inserted in the inserted state is formed. ing. Further, the rear end of the held portion 10 </ b> A is configured to come into contact with the front end of the intermediate element 49.

  In the hammer drill 1 having the above-described configuration, when starting drilling work on a workpiece (not shown) with the tip tool 10, the trigger 22A is pulled while the tip tool 10 is not in contact with the workpiece (not shown). 3 is rotated. In this state, since the weight 61 is not urged rearward by the operation portion 63, the locked portion 61B is locked by the locking portion 24D and the rotation around the shaft is restricted, and the weight 61 is rotated integrally with the cylinder 43A. Never do. When the tip tool 10 is pressed against a workpiece (not shown) in this state, the tip tool 10 moves backward relative to the housing 2 (cylinder 43A) as shown in FIG. Along with this movement, the meson 49 also moves rearward, so that the annular member 64 attached to the meson 49 also moves rearward. Along with this, the weight 61 rotates coaxially with the cylinder 43A as the locked portion 61B disengages from the locking portion 24D and the engaged portion 61A engages with the engaging portion 52B.

  Before the tip tool 10 comes into contact with a work material (not shown), the motor 3 is not loaded. Therefore, as shown in the graph of FIG. 4, the rotation speed is in a high rotation speed (rotation speed RH). . On the other hand, since the load is applied to the motor 3 after the tip tool 10 comes into contact with a workpiece (not shown), the rotation speed is low (see FIG. 4). Rotation number RL). The reason why the motor 3 is in the low rotation mode is mainly due to an increase in the load related to the impact. Specifically, when the tip tool 10 is pressed against a work material (not shown), the intermediate member 49 and the striker 48 are moved rearward, and the volume of the air chamber 43d is reduced. Since the stroke amount does not change, the compression rate of the air chamber 43d increases, the reaction force of the piston 47 increases, and the load on the motor 3 that drives the piston 47 increases. At the same time as the load on the motor 3 increases, the striker 48 moves forward due to the pressure of the compressed air chamber 43d, strikes the intermediate piece 49, and this striking force is transmitted to the tip tool 10 so that The not-shown work material is hit and the rotational speed of the motor 3 converges to the rotational speed RL. That is, when the rotational speed of the motor 3 decreases in the load state and converges to a constant rotational speed RL according to the load state, the output characteristics of the motor 3, the shape of the cylinder 43A, the piston 47, and the striker 48, In various properties such as the stroke amount, the converged rotation speed RL becomes a rotation speed suitable for the load state.

  Since the rotational speed RH in the no-load state is higher than the constant rotational speed RL corresponding to the load state, the striker 48 cannot follow the phase change of the piston 47 when shifting from the no-load state to the load state. In some cases, bad hitting may occur.

  In particular, when the pressure drop inside the drilling tool main body occurs, the hitting failure is remarkably generated. This pressure drop means that after the hammer drill is used, the temperature of the main body, which has become high, drops to room temperature, and the pressure inside the cylinder case that contains the hammering mechanism also decreases, but the pressure inside the hammering mechanism when the hammer drill is used increases. Therefore, the pressure inside the cylinder case (striking mechanism) is negative compared to before using the main body because air flows out of the cylinder case. When a hammer drill is used in this negative pressure state, the amplitude of the reciprocating motion of the striker is reduced due to a decrease in the compression force of the air chamber, and the striker does not go to the strike point where it comes into contact with the intermediate element. Since the speed when colliding with the intermediate element at the hitting point becomes small, the speed at which it collides and bounces is reduced, the amplitude energy of the hitting element is not amplified, and the hitting force by the tip tool is significantly reduced, or the tip tool The hitting failure that does not shift to the hitting operation state occurs.

  On the other hand, in the hammer drill 1 according to the present embodiment, the motor 3 is in a loaded state when the tip tool 10 is pressed against a work material (not shown). At this time, the weight 61 is simultaneously applied to the cylinder 43A. Engage. Since the cylinder 43A is rotating but the weight 61 is not rotating, and the weight 61 is heavy, the rotation of the cylinder 43A is suppressed by engaging the weight 61 with the cylinder 43A. The Since the cylinder 43A is connected to the motor 3 by the rotation transmission mechanism 5, the rotation of the motor 3 is also suppressed, and the rotation speed of the motor 3 is reduced to a rotation speed RC slightly larger than the rotation speed RL. By setting the motor 3 to the rotational speed RC, the rotational speed of the motor 3 can be converged to the rotational speed RL at the time of loading immediately after the tip tool 10 is pressed against the workpiece (not shown), and the phase of the piston 47 And the phase of the striker 48 can be synchronized to perform a suitable strike.

  In general, the lower the reciprocating speed of the piston, the longer the time from when the piston pulls the striker through the air chamber until the piston phase changes and the air chamber is compressed to push the striker, Since the amplitude of the striker increases, the condition for shifting to the strike operation is advantageous. On the other hand, in this embodiment, since the motor 3 is reduced to the rotational speed RC almost simultaneously with pressing the tip tool 10 against a workpiece (not shown), the tip tool 10 is pressed against a workpiece (not shown). At the same time, the reciprocating speed of the piston 47 can be reduced, and a stable striking operation of the tip tool 10 can be obtained.

1: Hammer drill 2: Housing 3: Motor 4: Blowing mechanism part 5: Rotation transmission mechanism part 6: Weight part 10: Tip tool 10A: Held part 10a: Groove part 21: Motor housing 22: Handle 22A: Trigger 22B: Power cord 23: Gear cover 24: Cylinder case 24A: Bearing 24B: Bearing 24C: Rotation locking member 24D: Locking portion 31: Output shaft portion 31A: Pinion gear 32: Fan 33: Bearing 41: Gear portion 41A: Bearing 41B: Bearing 42: Crank part 42A: Crank 42B: Connecting rod 43: Cylinder part 43A: Cylinder 43B: Rib 43a: Through hole 43b: Long hole 43c: Air hole 43d: Air chamber 44: Partition part 45: Tip tool holding part 45A: Ball 45B: Sleeve 45C: Spring 46: Strike part 47: Piston 47A: O-ring 47B: Piston pin 48: Batter 48A: O-ring 49: Meson
49A: O-ring 49B: Rear end portion 49C: Step 51: Drive portion side gear portion 51A: Flat gear 51B: Bevel gear 51C: Bearing 51D: Bearing 52: Spindle side gear portion 52A: Bevel gear 52B: Engagement portion 53: Key 61: Weight 61A: Engagement part 61B: Engagement part 62: Spring 62A: Washer 63: Operation part 64: Ring member 65: Pin 66: Sleeve

Claims (5)

A drive unit that outputs rotational force;
An impact mechanism that converts the rotational force into the impact force and transmits the impact force to the tip tool;
A rotation transmission mechanism that transmits the rotational force to the tip tool;
The striking mechanism unit is driven by the driving unit to reciprocate, a striking element that is interposed between the piston and the tip tool and transmits the reciprocating motion of the piston to the tip tool as striking force, The piston is inserted from one end in the axial direction so that the piston and the striker are slidably incorporated in the axial direction, and an air chamber sealed between the piston and the striker can be defined inside. And a cylinder portion mounted on the other end side in the axial direction so that the tip tool is slidable in the axial direction and integrally rotates,
The rotation transmission mechanism has a gear mechanism that is driven by the drive unit and engages with the cylinder unit to rotate the cylinder unit,
Providing a weight portion movable in the axial direction with respect to the cylinder portion;
The weight tool is configured to be able to come into contact with the gear mechanism as the tip tool moves to one side in the axial direction. The weight portion is engageable with the gear mechanism and is positioned on the other axial side of the gear mechanism and rotatably mounted on the cylinder portion, and is positioned on the other axial side of the weight. An operation portion configured to be movable in the axial direction with respect to the cylinder portion and immovable in the circumferential direction around the axis of the cylinder portion, and
The operation portion is configured to move to the one axial direction as the tip tool moves to the one axial direction, and to engage the weight with the gear mechanism. The drilling tool according to claim 1. A housing that rotatably supports the cylinder portion about the axis of the cylinder portion;
3. The perforation according to claim 1, wherein the housing includes a locking portion that engages with the weight portion in a state where the weight portion is not engaged with the gear mechanism. tool.   The engaged portion that engages with the gear mechanism is provided in the weight portion, and the engaged portion and the gear mechanism are configured in a gear shape that meshes with each other. The drilling tool according to claim 3. A drive unit that outputs rotational force;
A piston driven and reciprocated by the drive unit;
A striker reaching the reciprocating motion of the piston;
A cylinder portion that slidably houses the piston and the striker in the axial direction;
A gear mechanism that is driven by the drive unit and engages with the cylinder unit to rotate the cylinder unit,
A weight part movable in the axial direction is provided for the cylinder part,
When the tip tool is pressed against the work material, the weight moves and contacts a part of the rotation transmission mechanism.

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