JP2011156603A - Hammering tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hammering tool in which operability in changing over modes is not degraded, an attachment angle of an end tool is surely fixed, and workability is not degraded. <P>SOLUTION: When a changeover member 44 is changed over to a hammering mode, a first eccentric pin 44C pushes a coupling member 34 against urging force of a second spring 42 to slide the coupling member 34 forward. This disengages a spline engaging part 28A from a spline groove part 34A. An end of the coupling member 34 is inserted into a rotary locking member 37, causing a thread 34B to engage with a thread 37A. The rotary locking member 37 is prevented from rotating by an uneven part 37B, and the coupling member 34 engaging with the rotary locking member 37 cannot rotate, either. A second eccentric pin 44D engages with a groove of a groove part 37C, and thereby restricts movement of a cylinder 31 of the rotary locking member 37 in an axial direction, so as to fix the rotary locking member 37. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a striking tool such as a hammer or a hammer drill, and more particularly to a striking tool that imparts striking force and rotational force to a tip tool.

  12 to 20 show a hammer drill as an example of a conventional impact tool. The connecting member 534 is provided so as to be movable in the axial direction of the hammer drill, and is biased toward the bevel gear 525 by a spring 542. A rotation locking member 537 that restricts the rotation of the cylinder 531 by being engaged with the connection member 534 is provided on the end tool 550 side of the connection member 534. A slide sleeve 541 is provided on the outer peripheral side of the cylinder 531 so as to be movable in the axial direction of the hammer drill. In the slide sleeve 541, the end surface on the tip tool 550 side of the flange portion 541A is in contact with the rotation locking member 537, and the end surface on the piston 533 side of the flange portion 541A is in contact with the spring 542. The rotation locking member 537 is biased toward the piston 533 by the spring 543 having a biasing force larger than that of the spring 542, and the slide sleeve 541 is also biased toward the piston 533 via the rotation locking member 537. Is in contact with the abutting portion 545 on the outer periphery of the.

  A switching member 544 is rotatably provided on the outer frame member 530. As shown in FIGS. 16 to 20, the switching member 544 includes an eccentric pin 544 </ b> A that engages with the connecting member 534 and a cam portion 544 </ b> B that engages with the rotation locking member 537. When the switching member 544 is operated by the user, the hammer drill is operated in an impact / rotation mode (FIGS. 12 and 16), an impact mode (FIGS. 13 and 17), a neutral mode (FIGS. 14 and 18), and a rotation mode ( 15 and 19). Such a conventional configuration is described in Patent Document 1.

JP2009-241229

  In the hitting tool such as the conventional hammer drill described above, the positions of the connecting member 534, the rotation locking member 537, and the slide sleeve 541 are defined by the spring 542. For this reason, when the main body is strongly pressed against a workpiece such as wood from a certain height during the striking mode, or when the main body is lifted and idle shot occurs, the connecting member 534 and the rotation locking member 537, In some cases, the slide sleeve 541 moves and the engagement between the connecting member 534 and the rotation locking member 537 is instantaneously released. When the engagement between the connecting member 534 and the rotation locking member 537 is released during the impact, the cylinder 531 can be rotated, and the tip tool 550 rotates to change the mounting angle.

  The present invention eliminates the above-mentioned problems of the prior art, and can fix the mounting angle of the tip tool reliably without deteriorating the operability of mode switching, and an impact tool that does not deteriorate workability. The purpose is to provide.

  In order to achieve the above object, the present invention includes a housing, a motor accommodated in the housing, a substantially cylindrical cylinder rotatably supported in the housing for holding a tip tool, A piston provided slidably around the circumference, a conversion mechanism for converting the rotation of the motor into a reciprocating motion of the piston, and a reciprocating movement between a first position and a second position in the axial direction of the cylinder And a connecting member that rotates integrally with the cylinder. When the connecting member is in the first position, the rotation of the motor is transmitted to the cylinder so that the cylinder is centered on its axis. A rotation transmission mechanism that rotates and prevents transmission of rotation of the motor to the cylinder when the connection member is in the second position; and a position of the connection member in the axial direction of the cylinder Position or the number And switching means for switching to the position of the cylinder, and is provided in the housing so as to be non-rotatable and reciprocally movable in the axial direction of the cylinder. When the coupling means is in the first position, In addition, when the connecting member is in the second position, the connecting member is engaged with the connecting member to restrict the rotation of the cylinder, and the switching means causes the connecting member to move to the second position. A striking tool comprising: a fixing means for fixing the rotation locking member when disposed in the position.

  The fixing means is preferably provided in the switching means.

  Further, the switching means includes a cam portion that is rotatably supported by the housing, and protrudes from the cam portion toward the connecting member, and comes into contact with the connecting member as the cam portion rotates. A first eccentric pin that moves the connecting member from the first position to the second position, and the fixing means rotates the rotation means from a position different from the first eccentric pin of the switching means. A second eccentric pin that protrudes toward the locking member, and the rotation locking member is moved to the second position by the rotation of the switching means; The second eccentric pin restricts movement of the rotary locking member in the axial direction of the cylinder by engaging with the groove. Is desirable.

  Further, the switching means includes a base body that is gripped by a user and provided rotatably with respect to the housing, and the cam portion extends from the base body, and the rotation center of the base body rotates with the rotation of the base body. It is desirable that the second eccentric pin protrudes from the base toward the rotation locking member.

  The distance from the rotation center of the cam portion to the axis of the second eccentric pin is preferably larger than the distance from the rotation center of the cam portion to the axis of the first eccentric pin. .

  In order to achieve the above object, the present invention provides a housing, a motor accommodated in the housing, a crankshaft that rotates by rotation of the motor, a first breathing hole, and the first breathing hole. A cylinder having a second breathing hole formed on the crankshaft side with respect to the hole, the cylinder being rotatably supported in the housing and holding a tip tool; and the crankshaft A piston that is connected and reciprocates in the axial direction of the cylinder in the cylinder; an intermediate element that is reciprocally movable in the axial direction of the cylinder in the cylinder and that strikes the tip tool; In the axial direction of the cylinder so as to be able to reciprocate, strike the meson, and define an air chamber together with the piston and the cylinder. A striking element that closes the first breathing hole when moved more than a distance; a drive gear that converts the rotation of the motor into a rotational force of the cylinder; and a first position and a second position in the axial direction of the cylinder. A coupling member that is reciprocally movable with respect to the position and rotates integrally with the cylinder, and is engaged with the drive gear when the coupling member is in the first position. The rotation of the motor is transmitted to the cylinder, the cylinder is rotated about its axis, and the rotation of the motor to the cylinder is not engaged with the drive gear when the connecting member is in the second position. A rotation transmission mechanism that prevents transmission; and a rotation transmission mechanism that is non-rotatable in the housing and capable of reciprocating in the axial direction of the cylinder, and is connected to the connection member when the connection means is in the first position. The connecting member is in the second position A rotation locking member for restricting the rotation of the cylinder by engaging with the connecting member, and a shaft that is movable in the axial direction of the cylinder. A sliding sleeve that opens or closes the second breathing hole, biasing means that biases the sliding sleeve toward the piston, and a position of the connecting member in the axial direction of the cylinder Switching means having a first eccentric pin that switches the rotation locking member to the first position or the second position, and a cam portion that moves the rotation locking member in the axial direction of the cylinder. A striking tool comprising: a fixing means for fixing the rotation locking member when the connecting member is disposed at the second position.

  The fixing means includes a second eccentric pin that protrudes toward the rotation locking member from a position different from the first eccentric pin of the switching means, and the rotation locking member includes the switching means. When the connecting member is moved to the second position by rotation, a groove portion is formed in which the second eccentric pin can be engaged. It is desirable to restrict the movement of the rotation locking member in the axial direction of the cylinder only by engaging with the groove.

  The distance from the rotation center of the cam portion to the axis of the second eccentric pin is preferably larger than the distance from the rotation center of the cam portion to the axis of the first eccentric pin. .

  According to the striking tool of claim 1 or claim 6, the switching means switches the position of the connecting member in the axial direction of the cylinder to the first position or the second position, whereby the rotational force is applied to the tip tool. Switch whether or not to transmit. The striking tool is set to a striking mode in which only the striking force is transmitted without transmitting the rotational force to the tip tool when the connecting member is in the second position. In the impact mode, the rotation locking member restricts the rotation of the cylinder, and the fixing member fixes the rotation locking member, so that the main body is strongly pressed against a workpiece such as wood from a certain height during work. Even if the main body is lifted or the case where the main body is lifted and idling occurs, the connecting member and the rotation locking member do not move in the cylinder axial direction. Therefore, the engagement between the coupling member and the tooth row of the rotation locking member is not disengaged, and it is possible to reliably prevent the cylinder from rotating in the impact mode and the tip tool from rotating during the operation to change the mounting angle. it can.

  According to the striking tool of claim 2, since the fixing means is provided in the switching means, the position of the connecting member is switched to the second position to switch the striking tool to the striking mode, and at the same time, the rotation locking member. The fixing means can be moved to a position where the is fixed. Further, the rotation locking member can be fixed with a simple configuration.

  According to the striking tool of claim 3 or claim 7, when the connecting member is moved to the second position by the first eccentric pin, the second eccentric pin is also moved and formed on the rotation locking member. Engage with the groove. Therefore, at the same time that the impact tool is switched to the impact mode by the first eccentric pin, the rotation locking member can be fixed by the second eccentric pin. Further, the rotation locking member can be fixed with a simple configuration.

  According to the striking tool of claim 4, since the base and the cam portion, the first eccentric pin, and the second eccentric pin are integrally provided, the user of the striking tool rotates the base to perform the striking. Simultaneously with switching the tool to the striking mode, the first eccentric pin can move the connecting member to the second position, and the second eccentric pin can fix the rotation locking member.

  According to the impact tool of claim 5 or claim 8, when the first eccentric pin switches the connecting member to the first position as the switching means rotates, the second locking pin fixes the rotation locking member. It can prevent reliably that an eccentric pin contact | abuts to a connection member.

The whole perspective view which shows the whole impact tool by embodiment of this invention. Sectional drawing which shows the state at the time of the impact / rotation mode of the impact tool by embodiment of this invention. Sectional drawing which shows the state at the time of the impact mode of the impact tool by embodiment of this invention. Sectional drawing which shows the state at the time of the neutral mode of the impact tool by embodiment of this invention. Sectional drawing which shows the state at the time of the rotation mode of the impact tool by embodiment of this invention. The figure which shows the switching member at the time of the hit | damage / rotation mode of the impact tool by embodiment of this invention. The figure which shows the switching member at the time of the impact mode of the impact tool by embodiment of this invention. The figure which shows the switching member at the time of the neutral mode of the impact tool by embodiment of this invention. The figure which shows the switching member at the time of the rotation mode of the impact tool by embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS (a) Top view which shows the switching member of the impact tool by embodiment of this invention, (b) Side view, (c) Bottom view. The figure which shows the shape of the rotation locking member of the impact tool by embodiment of this invention. Sectional drawing which shows the state at the time of the conventional hit | damage and rotation mode. Sectional drawing which shows the state at the time of the impact mode of the conventional impact tool. Sectional drawing which shows the state at the time of the neutral mode of the conventional impact tool. Sectional drawing which shows the state at the time of the rotation mode of the conventional impact tool. The figure which shows the switching member at the time of the hit | damage and rotation mode of the conventional impact tool. The figure which shows the switching member at the time of the impact mode of the conventional impact tool. The figure which shows the switching member at the time of the neutral mode of the conventional impact tool. The figure which shows the switching member at the time of the rotation mode of the conventional impact tool. The switching member of the conventional impact tool (a) Top view, (b) Side view, (c) Bottom view.

  A striking tool according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing an entire hammer drill 1 as a typical striking tool, and a casing is constituted by a handle portion 10, a motor housing 20, and an outer frame member 30. FIG. A tool holding portion 60 that detachably holds the tip tool 50 is disposed on the side of the outer frame member 30 opposite to the handle portion 10. Further, in the vicinity of the tool holding portion 60, the side handle 40 extends from the outer frame member 30 in a detachable manner. In the following description, the direction in which the tip tool 50 extends is defined as the X direction, and the direction orthogonal to the direction (the direction in which the handle portion 10 extends) is defined as the Y direction. Further, the tip tool 50 side in the X direction is defined as the front side, the handle portion 10 side is defined as the rear side, the tool holding portion 60 side in the Y direction is defined as the upper side, and the side handle 40 side is defined as the lower side.

  A power cable 11 is attached to the handle portion 10 and a trigger 12 that can be operated by a user is attached. By connecting the power cable 11 to an external power source (not shown) and operating the trigger 12, the power supply can be switched between connection and disconnection.

  The motor housing 20 is provided in front of the handle portion 10. Although the handle portion 10 and the motor housing 20 have separate structures, they can be made of plastic and integrally molded. The outer frame member 30 is located above and in front of the motor housing 20.

  As shown in FIG. 2, a motor 21 is accommodated in the motor housing 20. The motor 21 includes a motor pinion shaft 22 and outputs a rotational driving force. A pinion 22 </ b> A is provided at the upper end of the motor pinion shaft 22. In the vicinity of the motor pinion shaft 22, a first rotation shaft 23 and a second rotation shaft 24 extend in parallel with the motor pinion shaft 22. The first rotating shaft 23 and the second rotating shaft 24 are supported by the motor housing 20 via bearings so as to be rotatable about the axis. A first gear 25 that meshes with the pinion 22 </ b> A is coaxially fixed to the lower portion of the first rotating shaft 23. A first bevel gear 27 is provided on the upper portion of the first rotating shaft 23 and meshes with a second bevel gear 28 described later. A second gear 26 that meshes with the pinion 22 </ b> A is coaxially fixed to the lower portion of the second rotating shaft 24. A crankshaft 29 is provided above the second rotating shaft 24 so as to rotate in the same rotational center as the second rotating shaft 24.

  A cylinder 31 is rotatably supported in the outer frame member 30 by a bearing fixed to the outer frame member 30. The cylinder 31 has a substantially cylindrical shape whose axial center extends in the X direction, and is formed with a first breathing hole 31a and a second breathing hole 31b. The second breathing hole 31b is formed on the rear side of the first breathing hole 31a. A tip tool 50 is detachably attached to the front of the cylinder 31. The first breathing hole 31a is always in communication with the outside air by a later-described gap 41a formed between the later-described slide sleeve 41 and the cylinder 31. An abutting portion 45 is provided on the outer periphery of the cylinder 31. Inside the cylinder 31, a piston 33, a striker 36, and an intermediate element 39 are arranged.

  A piston 33 is provided on the inner periphery of the cylinder 31 so as to be capable of reciprocating along the X direction. The piston 33 is connected to a front end portion of a connecting rod 35 that is rotatable about the Y direction as an axial direction. The rear end of the connecting rod 35 is connected to the crankshaft 29 so as to be rotatable about the Y direction. The second rotating shaft 24, the second gear 26, the crankshaft 29, and the connecting rod 35 constitute a conversion mechanism that converts the rotation of the electric motor 21 into the reciprocating motion of the piston 33.

  A striker 36 is disposed in front of the piston 33 and at a predetermined distance from the piston 33 so as to be able to reciprocate in the X direction. The outer peripheral surface of the striker 36 selectively opens and closes the first breathing hole 31a described above. A space surrounded by the striker 36, the piston 33, and the cylinder 31 is an air chamber 38, and the above-described second breathing hole 31b is positioned so as to open to the air chamber 38.

  An intermediate element 39 is disposed in front of the striker 36 so as to be slidable in the X-axis direction. The rear end portion of the intermediate piece 39 can come into contact with the striker 36, and the strike force is transmitted to the intermediate piece 39 by the striker 36. The front end portion of the meson 39 can come into contact with the rear portion of the tip tool 50, and the striking force is transmitted from the tip portion of the meson 39 to the tip tool 50. The tip tool 50 is held by the tool holding unit 60 and the cylinder 31.

  On the rear side of the cylinder 31, a second bevel gear 28 that is rotatably supported by a holding member 32 fixed to the outer frame member 30 is disposed so as to be rotatable with respect to the cylinder 31. A spline engaging portion 28 </ b> A is formed on the inner peripheral surface on the front side of the second bevel gear 28.

  A substantially cylindrical connecting member 34 is provided outside the cylinder 31 and in front of the second bevel gear 28 so as to rotate integrally with the cylinder 31 and slide in the X direction. The connecting member 34 has a spline groove portion 34A that can be engaged with the spline engaging portion 28A at the rear portion, and a tooth row 34B at the front portion. Specifically, the connecting member 34 includes a first position (FIG. 2) where the spline groove 34A engages with the spline engaging portion 28A in the X direction, and a second position where the spline groove 34A is separated from the spline engaging portion 28A. It is possible to reciprocate between these positions (FIG. 3). When the connecting member 34 is in the first position in a rotation / blow mode (FIG. 2) described later, the first rotating shaft 23 and the first gear 25, the first bevel gear 27, the second bevel gear 28, and the connecting member 34 are As a rotation transmission mechanism, the rotation of the motor 21 is transmitted to the cylinder 31, and the cylinder 31 is rotated about its axis. When the connecting member 34 is in the second position in an impact mode (FIG. 3) described later, the rotation transmitting mechanism transmits the rotation of the motor 21 to the cylinder 31 by separating the connecting member 34 from the second bevel gear 28. To prevent.

  The front end of the first spring 43 is fixed to the front end portion of the outer frame member 30. The rear end of the first spring 43 is fixed to a rotation locking member 37 described later. As a result, the first spring 43 biases the rotation locking member 37 backward with respect to the outer frame member 30. A second spring 42 that is fixed to the rotation locking member 37 via a slide sleeve 41 described later is provided behind the first spring 43. The second spring 42 has a rear end fixed to the connecting member 34 and a front end fixed to the slide sleeve 41. The second spring 42 biases the slide sleeve 41 forward with respect to the connecting member 34, and biases the connecting member 34 backward with respect to the slide sleeve 41. The urging force of the second spring 42 is smaller than the urging force of the first spring 43.

  A substantially cylindrical rotation locking member 37 is provided outside the cylinder 31 and in front of the connecting member 34 so as not to rotate with respect to the outer frame member 30 and to reciprocate in the X direction. ing. As shown in FIG. 11, a tooth row 37 </ b> A that can be engaged with the tooth row 34 </ b> B is provided on the inner peripheral surface on the rear side of the rotation locking member 37, and an uneven portion 37 </ b> B is provided on the outer peripheral surface side of the front end. . The tooth row 37A does not engage with the tooth row 34B when the connecting member 34 is in the first position in the rotation / blow mode (FIG. 2), and the connecting member 34 is in the second position in the hit mode (FIG. 3). When engaged with the tooth row 34B. The rotation locking member 37 restricts the rotation of the cylinder 31 by engaging the tooth row 37A with the tooth row 34B. The rotation locking member 37 is guided by the concavo-convex portion 37 </ b> B and can slide with respect to the outer frame member 30, and the rotation with respect to the outer frame member 30 is restricted. Further, a groove portion 37 </ b> C in which a groove that can be selectively engaged with a second eccentric pin 44 </ b> D of the switching member 44 described later is provided on the outer peripheral surface of the rear end of the rotation locking member 37. A first spring 43 is fixed to the front end of the rotation locking member 37 and is urged rearward by the first spring 43.

  A substantially cylindrical slide sleeve 41 is provided on the inner peripheral side of the rotation locking member 37 so as to be slidable with respect to the outer peripheral surface of the cylinder 31. A flange portion 41 </ b> A is provided on the front end surface of the slide sleeve 41, and the flange portion 41 </ b> A is in contact with the rotation locking member 37. The front end of the second spring 42 is fixed to the rear surface of the flange portion 41 </ b> A, and the slide sleeve 41 is biased forward with respect to the connecting member 32 by the second spring 42. The slide sleeve 41 is restricted from moving in the X direction by the abutting portion 45. Further, the inner peripheral surface of the slide sleeve 41 faces the first breathing hole 31a and the second breathing hole 31b formed in the cylinder 31, and the second breathing hole 31b is opened or closed by the axial movement of the slide sleeve 41. The structure is closed. The slide sleeve 41 defines a gap 41a with the cylinder 31, and always communicates the first breathing hole 31a with the outside air through the gap 41a.

  A switching member 44 shown in FIG. 10 is provided above the rotation locking member 37 and the connecting member 34. The switching member 44 includes a base body 44A, a cam portion 44B, a first eccentric pin 44C, and a second eccentric pin 44D. The base 44 </ b> A is provided so as to be rotatable with respect to the outer frame member 30 in a state where a part of the base 44 </ b> A is exposed for the user of the hammer drill 1 to grip. The cam portion 44B extends from the base body 44A and is rotatably supported by the outer frame member 30. Specifically, the cam portion 44B rotates around the rotation center of the base body 44A as the base 44A rotates. The first eccentric pin 44C protrudes from the cam portion 44B to the connecting member 34 side. The second eccentric pin 44D is disposed at a position different from the first eccentric pin 44C, and is provided on the base 44A so as to protrude to the rotation locking member 37 side. The distance from the rotation center of the cam portion 44B to the axis of the second eccentric pin 44D is larger than the distance from the rotation center of the cam portion 44B to the axis of the first eccentric pin 44C. When the user grips and rotates the base 44A, the first eccentric pin 44C comes into contact with the connecting member 34 with the rotation of the cam portion 44B and slides the connecting member 34 in the X direction. It can be moved to a first position (FIG. 2) and a second position (FIG. 3). At this time, the cam portion 44B pushes the rotation locking member 37 to slide the rotation locking member 37 in the X direction.

  Next, the operation of the hammer drill 1 will be described. The rotation output output from the motor 21 is transmitted to the first gear 25 by the pinion 22A. As the first gear 25 rotates, the first bevel gear 27 located on the same axis also rotates, and the second bevel gear 28 meshing with the first bevel gear 27 rotates. When the second bevel gear 28 and the connecting member 34 are engaged by the spline engaging portion 28 </ b> A and the spline groove portion 34 </ b> A, the rotational force is transmitted to the cylinder 31 via the connecting member 34. As a result, the tip tool 50 at the tip of the cylinder 31 rotates integrally with the cylinder 31. In this way, the rotational driving force is transmitted to the tip tool 50.

  The pinion 22 </ b> A is also meshed with the second gear 26, and the rotational force from the motor 21 is transmitted to the crankshaft 29 positioned coaxially with the second gear 26. The rotational motion is converted into a reciprocating motion by the crankshaft 29 and the connecting rod 35 connected to the crankshaft 29 and transmitted to the piston 33. In this state, when the tip tool 50 is pressed against the work material and the striker 36 is moved backward, the first breathing hole 31 a is blocked by the striker 36. When the second breathing hole 31b is blocked by the slide sleeve 41, the air chamber 38 is sealed. Then, the air in the air chamber 38 defined by the piston 33 and the striking element 36 is repeatedly compressed and expanded by the reciprocating motion of the piston 33, and reciprocating energy is applied to the striking element 36 through the air chamber 38. The striker 36 is in contact with the intermediate piece 39, and the intermediate piece 39 is in contact with the distal end tool 50 at the distal end portion, so that an impact force is applied to the distal end tool 50 through the intermediate piece 39.

  When the hammer drill 1 is operated with no load applied to the tip tool 50 or without the tip tool 50 attached, the striker 36 moves forward, and the rear end surface of the striker 36 passes through the first breathing hole 31a and passes through the first breathing hole 31a. The breathing hole 31a is opened. Then, even if the second breathing hole 31b is in a closed state, the air chamber 38 communicates with the outside air through the first breathing hole 31a, and the striking force is not transmitted to the tip tool 50. In this way, the hammer drill 1 is prevented from being idle.

  The hammer drill 1 can be switched between four modes: (1) impact / rotation mode, (2) impact mode, (3) neutral mode, and (4) rotation mode, by operating the switching member 44. Each mode will be described below.

  (1) Strike / rotation mode

  The striking / rotating mode will be described with reference to FIGS. 6 is a view of the switching member 44 of FIG. 2 as viewed from the motor 21 side, and shows the positional relationship between the cam portion 44B, the first eccentric pin 44C, and the second eccentric pin 44D.

  In the impact / rotation mode, the first eccentric pin 44C is disposed at the position shown in FIG. 2, and the connecting member 34 is moved to the first position by the urging force of the second spring 42. The spline groove portion 34A and the spline engaging portion 28A Engage. Thereby, the rotation of the second bevel gear 28 is transmitted to the tip tool 50 via the connecting member 34 and the cylinder 31. The second eccentric pin 44 </ b> D is separated from the groove portion 37 </ b> C of the rotation locking member 37.

  The cam portion 44 </ b> B is not in contact with the tooth row 37 </ b> A of the rotation locking member 37, and the rotation locking member 37 is urged rearward by the first spring 43. Further, the urging force of the first spring 43 is transmitted to the slide sleeve 41 via the rotation locking member 37, and the slide sleeve 41 contacts the abutting portion 45. As a result, the second breathing hole 31b is closed and the air chamber 38 is sealed. In this state, when the striker 36 moves backward to close the first breathing hole 31a, a strike force is applied to the tip tool 50. In this way, both the striking force and the rotational force are applied to the tip tool 50 in the striking / rotating mode.

  (2) Strike mode

  The striking mode will be described with reference to FIGS. 7 is a view of the switching member 44 of FIG. 3 as viewed from the motor 21 side, and shows the positional relationship between the cam portion 44B, the first eccentric pin 44C, and the second eccentric pin 44D. As shown in FIG. 7, when the switching member 44 is switched to the striking mode, the first eccentric pin 44C moves forward.

  The first eccentric pin 44C pushes the connecting member 34 against the urging force of the second spring 42, slides the connecting member 34 forward, and moves the connecting member 34 to the second position. As a result, the engagement between the spline engaging portion 28A and the spline groove portion 34A is released. When the connecting member 34 moves forward, the distal end portion of the connecting member 34 is inserted into the rotation locking member 37, and the tooth row 34B and the tooth row 37A are engaged. Since the rotation locking member 37 is prevented from rotating by the concavo-convex portion 37 </ b> B, the connecting member 34 engaged with the rotation locking member 37 also cannot rotate. Further, the cylinder 31 engaged with the connecting member 34 also cannot rotate, and the second bevel gear 28 idles on the cylinder 31, so that the rotational force is not transmitted to the tip tool 50.

  Since the slide sleeve 41 abuts against the abutting portion 45 and closes the second breathing hole 31b, the tip tool 50 is pressed against the work material and the striker 36 is moved backward to close the first breathing hole 31a. The air chamber 38 is sealed. As a result, the piston 33 reciprocates and an impact force is applied to the tip tool 50 via the air chamber 38. Thus, only the striking force is applied to the tip tool 50 in the striking mode.

  In the hitting mode, the second eccentric pin 44D regulates the movement of the rotation locking member 37 in the axial direction of the cylinder 31 by engaging with the groove of the groove portion 37C, and fixes the rotation locking member 37. .

  (3) Neutral mode

  The neutral mode will be described with reference to FIGS. FIG. 8 is a view of the switching member 44 of FIG. 4 as viewed from the motor 21 side, and shows the positional relationship between the cam portion 44B, the first eccentric pin 44C, and the second eccentric pin 44D. As shown in FIG. 8, when the switching member 44 is set to the neutral mode, the cam portion 44B and the first eccentric pin 44C move forward.

  In the neutral mode, the first eccentric pin 44C is disposed at the position shown in FIG. 4, the first eccentric pin 44C pushes the connecting member 34, and the connecting member 34 is moved forward against the urging force of the second spring 42. Slide. As a result, the engagement between the spline engaging portion 28A and the spline groove portion 34A is released. Therefore, the second bevel gear 28 idles on the cylinder 31 and no rotational force is transmitted to the tip tool 50.

  The cam portion 44 </ b> B pushes the rotation locking member 37 and slides the rotation locking member 37 forward against the urging force of the first spring 43. Since the slide sleeve 41 is in contact with the rotation locking member 37 at the flange portion 41A, the slide sleeve 41 moves forward by the biasing force of the second spring 42 as the rotation locking member 37 advances. As a result, the second breathing hole 31b is opened, and the air chamber 38 communicates with the outside air. Even if the piston 33 reciprocates in this state, the pressure in the air chamber 38 does not fluctuate and the striking force is not transmitted to the tip tool 50. In this way, neither the striking force nor the rotational force is applied to the tip tool 50 in the neutral mode. In the neutral mode, the second eccentric pin 44D is separated from the groove 37C.

  Further, since the rotation locking member 37 moves rearward and the tooth row 34B and the tooth row 37A are not engaged, the cylinder 31 can freely rotate. As a result, the tip tool 50 can be positioned in the rotational direction. For example, even when the tip tool 50 has a scoop-like directivity, the position of the tip tool in the rotational direction can be easily adjusted.

(4) Rotation mode

  The rotation mode will be described with reference to FIGS. FIG. 9 is a view of the switching member 44 of FIG. 5 as viewed from the motor 21 side, and shows the positional relationship between the cam portion 44B, the first eccentric pin 44C, and the second eccentric pin 44D. As shown in FIG. 9, the cam portion 44B moves forward by setting the switching member 44 to the rotation mode.

  In the rotation mode, the first eccentric pin 44C is disposed at the position shown in FIG. 5, and the connecting member 34 is engaged with the spline engaging portion 28A by the spline groove portion 34A by the urging force of the second spring 42. Thereby, the rotation of the second bevel gear 28 is transmitted to the tip tool 50 via the connecting member 34 and the cylinder 31.

  The cam portion 44 </ b> B pushes the rotation locking member 37 and slides the rotation locking member 37 forward against the urging force of the first spring 43. Since the slide sleeve 41 is in contact with the rotation locking member 37 at the flange portion 41 </ b> A, it moves forward by the urging force of the second spring 42. As a result, the second breathing hole 31b is opened, and the air chamber 38 communicates with the outside air. Even if the piston 33 reciprocates in this state, the pressure in the air chamber 38 does not fluctuate and the striking force is not transmitted to the tip tool 50. In this way, only the rotational force is applied to the tip tool 50 in the rotation mode. In the rotation mode, the second eccentric pin 44D is separated from the groove 37C.

  In the hammer drill 1 of the present embodiment described above, when switching to the striking mode by the switching member 44, the connecting member 34 moves to the second position and prevents transmission of the rotational force to the tip tool 50. In the impact mode, the rotation locking member 37 restricts the rotation of the cylinder 31 and the second eccentric pin 44D engages with the groove of the groove portion 37C to fix the rotation locking member 37. Even when the member is pressed strongly against a workpiece such as wood from a certain height, or even when the main body is lifted and idle driving occurs, the connecting member 34 and the rotation locking member 37 are connected to the shaft of the cylinder 31. There is no movement in the direction of the heart. Accordingly, the tooth row 34B of the connecting member 34 and the tooth row 37A of the rotation locking member 37 are not disengaged, the cylinder 31 rotates in the impact mode, the tip tool 50 rotates during the operation, and the mounting angle is increased. It can be surely prevented from changing.

  Further, since the switching member 44 is provided with the second eccentric pin 44D, the position of the connecting member 34 is moved to the second position (FIG. 7), and at the same time, the second eccentric pin 44D is moved and rotated. The groove 37C of the member 37 can be engaged. Therefore, at the same time when the hammer drill 1 is switched to the striking mode by the first eccentric pin 44C, the rotation locking member 37 can be fixed by the second eccentric pin 44D. Thus, the rotation locking member 37 can be fixed with a simple configuration.

  Further, since the base 44A, the cam portion 44B, the first eccentric pin 44C, and the second eccentric pin 44D are integrally provided on the switching member 44, the user of the hammer drill 1 rotates the base 44A to remove the hammer drill 1. Simultaneously with switching to the striking mode, the first eccentric pin 44C moves the connecting member 34 to the second position, and the second eccentric pin 44D can fix the rotation locking member 37.

  The distance from the rotation center of the cam portion 44B to the axis of the second eccentric pin 44D is larger than the distance from the rotation center of the cam portion 44B to the axis of the first eccentric pin 44C. When the first eccentric pin 44C switches the connecting member 34 to the first position along with the rotation of the rotation, the second eccentric pin 44D for fixing the rotation locking member 37 is reliably prevented from coming into contact with the connecting member 34. can do.

  In addition, the impact tool by this invention is not limited to embodiment mentioned above, A various change is possible in the range of the summary of the invention described in the claim. For example, the rotation locking member and the slide sleeve can be molded as an integral sleeve. In addition, the rotation transmission may be switched by using a tooth structure, a spline engagement portion, or the like as a clutch structure and detaching the connecting member, the sleeve, and the rotation transmission portion.

  The striking tool of the present invention can be used for a hammer drill or the like having a striking mode in which only a striking is performed without applying a rotational force.

DESCRIPTION OF SYMBOLS 1: Hammer drill, 10: Handle part, 11: Power supply cable, 12: Trigger, 20: Motor housing, 21: Motor, 22: Motor pinion shaft, 22A: Pinion, 23: First rotating shaft, 24: Second rotating shaft 25: first gear, 26: second gear, 27: first bevel gear, 28: second bevel gear, 28a: spline engaging portion, 29: crankshaft, 30: outer frame member, 31: cylinder, 31a : 1st breathing hole, 31b: 2nd breathing hole, 32: Holding member, 33: Piston, 34: Connecting member, 34A: Spline groove part, 34B: Teeth row, 35: Connecting rod, 36: Strike element, 37: Rotating unit Stop member, 37A: dentition, 37B: concavo-convex part, 37C: groove part, 38: air chamber, 39: meson, 40: side handle, 41: sly Sleeve: 41A: Flange part 42: Second spring 43: First spring 44: Switching member 44A: Base body 44B: Cam part 44C: First eccentric pin 44D: Second eccentric pin 45: Projection This part, 50: Tip tool, 60: Tool holding part

Claims (8)

A housing;
A motor housed in the housing;
A substantially cylindrical cylinder rotatably supported in the housing to hold the tip tool;
A piston slidably provided on the inner periphery of the cylinder;
A conversion mechanism for converting the rotation of the motor into a reciprocating motion of the piston;
A connecting member that is reciprocally movable between a first position and a second position in the axial direction of the cylinder and that rotates integrally with the cylinder; and the connecting member is located at the first position. The rotation of the motor is transmitted to the cylinder at a time to rotate the cylinder about its axis, and the transmission of the rotation of the motor to the cylinder is prevented when the connecting member is in the second position. A rotation transmission mechanism;
Switching means for switching the position of the connecting member in the axial direction of the cylinder to the first position or the second position;
Provided in the housing so as not to rotate and to be able to reciprocate in the axial direction of the cylinder. When the connecting means is in the first position, the connecting member does not engage the connecting member, and the connecting member A rotation locking member that restricts rotation of the cylinder by engaging with the connecting member when in the second position;
An impact tool comprising: fixing means for fixing the rotation locking member when the connecting member is arranged at the second position by the switching means.   The impact tool according to claim 1, wherein the fixing means is provided in the switching means. The switching means is
A cam portion rotatably supported by the housing;
A first member that protrudes from the cam portion toward the connecting member and contacts the connecting member as the cam portion rotates to move the connecting member from the first position to the second position. An eccentric pin,
The fixing means has a second eccentric pin protruding from the position different from the first eccentric pin in the switching means toward the rotation locking member.
The rotation locking member has a groove portion in which a groove that can be engaged with the second eccentric pin is formed when the connecting member is moved to the second position by rotation of the switching means.
The impact tool according to claim 2, wherein the second eccentric pin restricts movement of the rotation locking member in an axial direction of the cylinder by engaging with the groove. Further, the switching means has a base that is gripped by a user and provided rotatably with respect to the housing,
The cam portion extends from the base body, and rotates with the rotation center of the base body as the rotation center as the base body rotates.
The impact tool according to claim 3, wherein the second eccentric pin protrudes from the base toward the rotation locking member.   The distance from the rotation center of the cam portion to the axis of the second eccentric pin is greater than the distance from the rotation center of the cam portion to the axis of the first eccentric pin. The impact tool according to claim 3 or 4. A housing;
A motor housed in the housing;
A crankshaft that is rotated by rotation of the motor;
A substantially cylindrical shape in which a first breathing hole and a second breathing hole formed on the crankshaft side of the first breathing hole are formed, and rotatably supported in the housing; A cylinder for holding the tip tool;
A piston connected to the crankshaft and reciprocating in the axial direction of the cylinder in the cylinder;
An intermediate member that is reciprocally movable in the axial direction of the cylinder in the cylinder and that strikes the tip tool;
In the cylinder, provided so as to be able to reciprocate in the axial direction of the cylinder, hitting the meson, and defining an air chamber together with the piston and the cylinder, and when the meson moves to the piston more than a predetermined distance A striker that occludes the first breathing hole;
A drive gear that converts the rotation of the motor into a rotational force of the cylinder and a reciprocating movement between the first position and the second position in the axial direction of the cylinder, and is integrated with the cylinder A rotating connecting member, and when the connecting member is in the first position, the rotation of the motor is transmitted to the cylinder by engaging with the drive gear so that the cylinder is centered on its axis. A rotation transmission mechanism for preventing transmission of rotation of the motor to the cylinder without engaging with the drive gear when the connecting member is in the second position;
Provided in the housing so as not to rotate and to be able to reciprocate in the axial direction of the cylinder. When the connecting means is in the first position, the connecting member does not engage with the connecting member, A rotation locking member that restricts rotation of the cylinder by engaging with the connecting member when in the second position;
A slide sleeve provided so as to be movable in the axial direction of the cylinder, moving in the axial direction of the cylinder in accordance with the movement of the rotation locking member, and opening or closing the second breathing hole;
Biasing means for biasing the slide sleeve toward the piston;
A first eccentric pin for switching the position of the coupling member in the axial direction of the cylinder to the first position or the second position; and a cam portion for moving the rotation locking member in the axial direction of the cylinder Switching means comprising:
An impact tool comprising: fixing means for fixing the rotation locking member when the connecting member is arranged at the second position by the switching means. The fixing means has a second eccentric pin protruding from the position different from the first eccentric pin in the switching means toward the rotation locking member.
The rotation locking member has a groove portion in which a groove that can be engaged with the second eccentric pin is formed when the connecting member is moved to the second position by rotation of the switching means.
The impact according to claim 6, wherein the second eccentric pin restricts movement of the rotary locking member in the axial direction of the cylinder by engaging with the groove only in the impact mode. tool.   The distance from the rotation center of the cam portion to the axis of the second eccentric pin is greater than the distance from the rotation center of the cam portion to the axis of the first eccentric pin. The impact tool according to claim 7.

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