JP2005034913A - Hammer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact hammer having a short total length, and reduced in the number of part items. <P>SOLUTION: A tool holder 50 is detachably arranged in a tip part of a tool body, and a tip tool 35 is detachably arranged in the tool holder. A tool sleeve 51 is attached-detached by a sphere 54, a first fixing member 55, and a first operation sleeve 56 for forming a cylinder engaging-releasing mechanism to a tip part of a cylinder 34 extending in the tool body. The tip tool 35 is attached-detached by a sphere 64, a second fixing member 65, and a second operation sleeve for forming a tool engaging-releasing mechanism to the tool sleeve 51. One compression spring 52 mutually energizes the first and second fixing members in the opposite direction, to maintain the mutual connecting-fixing relationship. When an operation sleeve is moved against energizing force of the compression spring, the mutual connecting relationship is cut off. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hammering tool such as a hammer or a hammer drill, and more particularly to a tool holder in which a tip tool can be easily removed and mounted, and can be mounted on or replaced with a hammering tool body.
[0002]
[Prior art]
Conventional hammering tools such as hammers and hammer drills have an electric motor that generates rotational driving force, a cylinder that can be rotated by the rotational driving force from the electric motor, and a motion conversion that converts the rotational driving force from the electric motor into reciprocating motion. , A piston portion that generates a striking force by reciprocating motion from the motion converting portion, a tool holder that is detachably connected to the tip of the cylinder, and holds the tip tool, and a striking force that transmits the striking force from the piston portion to the tip tool And a transmission unit. The tool holder is easy to attach and detach the tip tool, and at the same time, the tool holder itself is attached to the impact tool body so as to be detachable. By making the tool holder replaceable, various tip tools can be used, and the use of the impact tool main body is expanded. The conventional tool holder uses one spring for attaching / detaching the tip tool to / from the tool holder, and uses another spring for attaching / detaching the tool holder to / from the tool body. (For example, refer to Patent Document 1 and FIG. 2).
[Patent Document 1]
UK Patent Application No. 2333980 Specification
[Problems to be solved by the invention]
However, in the conventional tool holder for impact tools, separate springs are used for engaging the tip tool and for engaging the tool holder with the main body of the tool holder, so that the overall length of the tool holder is increased and two spaces for fixing the spring are required. Become. Therefore, a compact tool holder cannot be obtained, and the number of parts is large, so there is a limit to cost reduction.
[0004]
Accordingly, an object of the present invention is to provide a striking tool including a compact tool holder that can reduce the number of parts and has a simple structure and a reduced overall length.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides an electric motor that generates rotational driving force, a cylinder that can be rotated by the rotational driving force from the electric motor, and a rotational driving force from the electric motor that is converted into a reciprocating motion. A motion converting portion, a piston portion that generates a striking force by reciprocating motion from the motion converting portion, a tool holder that is detachably connected to the tip of the cylinder, and holds a tip tool, and the tip tool from the piston portion In a striking tool having a striking force transmitting portion for transmitting a striking force of the tool, a tool sleeve for internally mounting the tip tool, and a cylinder engagement / release mechanism for maintaining or releasing the engagement between the tool sleeve and the tip of the cylinder A tool engagement / release mechanism for maintaining or releasing the engagement between the tool sleeve and the tip tool, and the tool positioned between the tool engagement / release mechanism and the cylinder engagement / release mechanism. A spring provided concentrically on the outer periphery of the rib, and the spring biases the tool engagement / release mechanism in the distal direction to maintain the engagement between the tool sleeve and the distal tool, Further, an impact tool is provided that biases the cylinder engagement / release mechanism in a direction opposite to the tip direction to maintain the engagement state between the cylinder and the tool sleeve.
[0006]
Here, a first through hole and a second through hole are formed in the tool sleeve, a recess is formed in the outer periphery of the cylinder, and the cylinder engagement / release mechanism is engaged with the recess in the first through hole. A first locking member arranged to be able to be coupled, and the first spring being biased in a direction opposite to the tip tool to fix the engagement between the first locking member and the recess. A first fixing member in contact with the outer periphery of the first locking member; and a first operation sleeve connected to the first fixing member and movable in an axial direction of the sleeve, and moving the first operation sleeve in a distal direction By operating, the engagement state of the cylinder and the tool sleeve is released, and the tool engagement / release mechanism is engageable with the tip tool inserted into the tool sleeve in the second through hole. A second locking member disposed on the second locking member and urged in the distal direction by the one spring, the second locking portion A second fixing member in contact with the outer periphery of the second locking member so as to fix the engagement between the tool and the tip tool, and a second operation sleeve connected to the second fixing member and movable in the axial direction of the tool sleeve And the engagement state between the tip tool and the tool sleeve is released by moving the second operation sleeve in the opposite direction.
[0007]
Further, at least two of the first through holes are formed in the tool sleeve, and the first locking members are provided in the first through holes, respectively, corresponding to the first locking members. It is desirable that the recess and the first fixing member are provided.
[0008]
The first operating sleeve and the second operating sleeve are arranged concentrically with the tool sleeve, and the diameter of the second operating sleeve close to the first operating sleeve is close to the distal end side of the second operating sleeve. The first operating sleeve has a large diameter portion that is larger than the portion, and the first operating sleeve has a small diameter portion in which the diameter of the portion close to the second operating sleeve is smaller than the portion opposite to the tip side of the first operating sleeve The small diameter portion is sized to be accommodated in the large diameter portion, and the one spring is preferably arranged concentrically in a space defined by the large diameter portion and the small diameter portion.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
A tool holder for an impact tool according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a partial cross-sectional view showing the overall configuration of a hammer drill, which is a typical striking tool, and the handle body 10, motor housing 20, gear housing 30 and support member 30A constitute a tool body.
[0010]
A power cable 11 is attached to the handle portion 10, a switch mechanism 12 is built in, and a trigger 13 mechanically connected to the switch mechanism 12 is provided to be operable. The power cable 11 is connected to a switch mechanism 12 and an external power source (not shown), and the trigger 13 can be operated to switch between connection and disconnection with the power source.
[0011]
The motor housing 20 is connected to the handle portion 10. The handle portion 10 and the motor housing 20 are each a molded product made of resin, but both may be an integrally molded product. An electric motor 21 is accommodated in the motor housing 20. The electric motor 21 outputs a rotational driving force from the motor pinion shaft 22.
[0012]
The gear housing 30 is a resin molded product provided in front of the motor housing 20. The support member 30 </ b> A is made of metal and is provided inside the gear housing 30. Below the gear housing 30 is provided an intermediate shaft 32 that is parallel to the motor pinion shaft 22 and is rotatably supported by the support member 30A. A first gear 31 is fixedly mounted on the motor side end of the intermediate shaft 32 and meshes with the motor pinion shaft 22, and a gear portion 32A is formed on the tip side of the intermediate shaft 32 and meshes with a second gear 33 described later. is doing. The support member 30A further supports the motor pinion shaft 22 of the electric motor 21 via a bearing so as to be rotatable.
[0013]
A cylinder 34 extends parallel to the motor pinion shaft 22 and is rotatably supported by the support member 30A. The second gear 33 is fixed to the outer periphery of the cylinder 34, and the cylinder 34 can rotate about its axis by meshing with the gear portion 32A described above. A tool holder 50 is detachably attached to the distal end side of the cylinder 34, and a tip tool 35 is detachably attached in the tool holder 50.
[0014]
The intermediate shaft 32 is spline-engaged with a clutch 36 that is urged toward the electric motor 21 by a spring at an intermediate portion, and the clutch 36 is operated in a hammer drill mode (position shown in the figure) by a change lever 37 provided at the lower portion of the gear housing 30. ) And drill mode (position where the clutch 36 has moved in the distal direction). The motion conversion member 40 is rotatably mounted on the intermediate shaft 32 on the electric motor side of the clutch 36, and the arm portion 40 </ b> A of the motion conversion member 40 is provided so as to reciprocate in the front-rear direction of the tool body by the rotation of the intermediate shaft 32. It is done.
[0015]
In the hammer drill mode, the intermediate shaft 32 and the motion conversion member 40 are coupled by the clutch 36. The motion conversion member 40 is connected to the piston 42 via a piston pin 41. The piston 42 is slidably mounted in the cylinder 34 so as to reciprocate in a direction parallel to the intermediate shaft 32. A striking element 43 is housed inside the piston 42, and an air chamber 44 is defined between the piston 42 and the striking element 43 in the cylinder 34. The striker 43 strikes the tip tool 35 via an intermediate element 45 (FIG. 2) disposed in the cylinder 34.
[0016]
The operation of the striking tool configured as above will be described. The rotation output of the electric motor 21 is transmitted from the pinion shaft 22 to the intermediate shaft 32 via the first gear 31. The rotation of the intermediate shaft 32 is transmitted to the cylinder 34 by meshing between the gear portion 32 </ b> A and the second gear 33 externally mounted on the cylinder 34. A tool holder 50 that holds a tip tool 35 is fixed to the tip of the cylinder 34 and rotates integrally with the cylinder 34. In this way, the rotational force is transmitted to the tip tool 35.
[0017]
On the other hand, when the change lever 37 is moved to the hammer drill mode, the clutch 36 is coupled to the motion converting member 40, and the rotational driving force of the intermediate shaft 32 is transmitted to the motion converting member 40. The motion converting member 40 converts the rotational driving force into the reciprocating motion of the piston 42 via the piston pin 41. The air chamber 44 defined between the striking element 43 and the piston 42 by the reciprocating motion of the piston 42 also repeats compression and expansion, and imparts striking force to the striking element 43. The striking element 43 moves forward and collides with the rear end surface of the intermediate element 45, and the striking force is transmitted to the tip tool 35 via the intermediate element 45. In this manner, in the hammer drill mode, the turning force and the striking force are simultaneously applied to the tip tool 35.
[0018]
When the change lever 37 is in the drill mode, the clutch 36 disconnects the intermediate shaft 32 and the motion conversion member 40, and only the rotational driving force of the intermediate shaft 32 is transferred to the cylinder 34 via the gear portion 32 </ b> A and the second gear 33. Is transmitted to. Therefore, only the rotational force is applied to the tip tool 35.
[0019]
2 to 4 are enlarged views showing the tip end side of the tool body and the tool holder 50 of the impact tool according to the present embodiment. The tool holder 50 includes a tool sleeve 51 for housing the tip tool 35, a cylinder engagement / release mechanism for maintaining or releasing the engagement between the tool holder 50 and the tip of the cylinder 34, and the tool holder 50 and the tip tool. A tool engaging / releasing mechanism for maintaining or releasing the engagement with 35, and a cylinder engaging / releasing mechanism and a tool engaging / releasing mechanism, disposed on the outer periphery of the tool sleeve 51, It is composed of a single compression spring 52 that urges the engagement / release mechanism in opposite directions.
[0020]
A plurality of first through holes 53 are formed on the rear side of the tool sleeve 51, and a plurality of recesses 34 a corresponding to the first through holes 53 are formed on the outer peripheral surface on the tip end side of the cylinder 34. The cylinder engaging / releasing mechanism includes a sphere 54 serving as a first locking member disposed in the first through hole 53 and a urging force of the compression coil spring 52 in the direction of the motor 21 to contact the outer periphery of the sphere 54. A first fixing member 55 that maintains the engagement of 34a, and a first operation sleeve 56 that is coupled to the first fixing member 55 so that the first fixing member 55 is movable in the axial direction of the tool sleeve 51. Is done.
[0021]
A second through hole 63 is formed through the tool sleeve 51 at a position that can be opposed to the groove 35 a of the tip tool 35 inserted through the tool sleeve 51. The tool engagement / release mechanism is configured by a compression coil spring 52 to fix the engagement between the sphere 64 as the second locking member disposed in the second through-hole 63 and the sphere 64 and the groove 35a of the tip tool 35. A second fixing member 65 that is biased in the distal direction and can be disposed on the outer periphery of the sphere 64, and a second fixing member 65 that is connected to the second fixing member 65 so as to be movable in the axial direction of the tool sleeve 51. 2 operation sleeves 66.
[0022]
The second operation sleeve 66 and the first operation sleeve 56 are arranged concentrically with the tool sleeve 51, and the second operation sleeve 66 has a diameter close to the first operation sleeve 56 close to the tip side of the second operation sleeve 56. The first operating sleeve 56 is made larger and has a larger diameter portion 66A, and the first operating sleeve 56 has a smaller diameter than the portion opposite to the distal end side of the first operating sleeve 56. Make. The small diameter portion 56 </ b> A of the first operation sleeve 56 is sized to be accommodated in the large diameter portion 66 </ b> A of the second operation sleeve 66. The compression coil spring 52 is disposed in a space defined by the large diameter portion 66A and the small diameter portion 56A. As shown in FIG. 3, a key 51A protruding inward in the radial direction for engaging with a key groove (not shown) of the tip tool is integrally provided on the inner peripheral surface of the tool sleeve 51.
[0023]
FIG. 2 shows a state in which the tool holder 50 is fixed to the cylinder 34 of the impact tool body, and at the same time, the tip tool 35 is mounted and fixed in the tool holder 50. In this state, the first operating sleeve 56 and the second operating sleeve 66 are urged in opposite directions by the urging force of the compression coil spring 52, and the first fixing member 55 is on the sphere 54, and the sphere 54, the recess 34a, and the like. Thus, the connection of the tool sleeve 51 to the cylinder 34 is maintained, and at the same time, the second fixing member 65 is on the sphere 64 and the engagement between the sphere 64 and the groove 35a of the tip tool 35 is maintained. Therefore, the fixing of the tip tool 35 to the tool sleeve 51 is maintained.
[0024]
The operation of releasing the tool holder 50 from the tool body from this state will be described. As shown in FIG. 3, when the first operation sleeve 56 is slid in the distal direction against the urging force of the compression coil spring 52, the small diameter portion 56 </ b> A of the first operation sleeve 56 is larger than the second operation sleeve 66. The first fixing member 55 moves in the distal direction while being gradually inserted into the diameter portion 66A. Therefore, the sphere 54 whose movement outward in the radial direction by the first fixing member 55 can be easily moved outward in the radial direction by the action of the inclined wall of the recess 34 a of the cylinder 34. Accordingly, the sphere 54 is detached from the recess 34a, and the tool holder 50 can be easily separated from the tool body by pulling the tool holder 50 further in the distal direction.
[0025]
When only the tip tool 35 is replaced, as shown in FIG. 4, the second operation sleeve 66 is slid in the direction of the impact tool main body against the urging force of the compression coil spring 52. While the large diameter portion 66A gradually covers the small diameter portion 56A of the first operation sleeve 56, the second fixing member 65 connected to the second operation sleeve 66 moves toward the impact tool main body. Accordingly, the sphere 64 whose movement in the radially outward direction is suppressed by the second fixing member 65 can easily move radially outward along the curved surface of the axial end portion of the groove 35a of the tip tool 35. When the spherical body 64 is detached from the groove 35a of the tip tool, the connection relation between the tip tool and the tool holder 50 is released, and the tip tool 35 can be easily pulled out forward.
[0026]
The impact tool according to the present invention is not limited to the above-described embodiments, and various modifications and improvements can be made within the scope described in the claims. For example, in FIG. 2 to FIG. 4, the cylinder engagement / release mechanism is shown with two engagement fixing positions in the vertical direction, but the function as the cylinder engagement / release mechanism can be obtained in either one of the vertical positions. . However, as a characteristic of the impact tool, rotational force, impact force, and vibration are concentrated around the tip tool. Therefore, it is desirable to ensure the engagement state at two upper and lower positions. Further, if the cylinder engaging / releasing mechanism is provided with four engagement fixing positions by being arranged vertically and horizontally, the engagement state is further ensured. Similarly, although the tool engagement / release mechanism is provided with one engagement fixing position on the upper side of the tool in the drawing, it may be provided two symmetrically in the vertical direction.
[0027]
【The invention's effect】
According to the striking tool of the first aspect, between the cylinder engagement / release mechanism and the tool engagement / release mechanism, one spring is disposed to urge both of them in opposite directions. The tool holder is always kept in engagement with the cylinder tip by the spring. When a force opposite to the spring biasing direction is applied to the cylinder engagement / release mechanism, the tool holder can be easily detached from the cylinder tip. Similarly, the engagement of the tip tool with the sleeve of the tool holder is maintained by this single spring, and when the force opposite to the urging direction of the spring is applied to the tool engagement / release mechanism, the tip tool can be easily attached to the tool holder. Can be disengaged from. Thus, since the two engagement / release mechanisms can be simultaneously energized by one spring, the entire tool holder can be made compact.
[0028]
According to the impact tool of the second aspect, the engagement state between the tool sleeve and the cylinder is released by moving the first operation sleeve to the tip side, and the tool holder can be detached from the cylinder. 2 The engagement state of the tool and the engagement member is released by moving the operation sleeve in the direction opposite to the tip, and the tool can be extracted from the tool holder. The spring is a member having a relatively long overall length. If two springs are provided, the overall length of the tool holder is increased accordingly. In the impact tool of the present invention, since the cylinder engagement / release mechanism and the tool engagement / release mechanism of the tool holder are arranged on both sides of one spring, a compact and short tool holding structure can be realized.
[0029]
According to the tool holder for an impact tool according to claim 3, at least two first through holes are formed in the tool sleeve, and a first locking member is provided in each of the first through holes. The recess and the first fixing member are provided. The effect can be obtained even if the cylinder engagement / release mechanism has only one engagement fixing position. However, if there are a plurality of upper and lower positions, the stability at the time of engagement is further increased. Since the springs are arranged concentrically, a plurality of engagement fixing portions can be provided concentrically, for example.
[0030]
According to the tool holder of the impact tool of the fourth aspect, the operation sleeves overlap each other during the attachment / detachment operation, and the overall length of the tool holder can be shortened.
[Brief description of the drawings]
FIG. 1 is a partial sectional view showing an entire impact tool according to an embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view of a main part of the impact tool shown in FIG. 1, showing a state in which a tip tool is fixed to a tool holder.
FIG. 3 is an enlarged cross-sectional view of a main part of the impact tool shown in FIG. 1, showing a state in which the tool holder is separated from the impact tool main body.
4 is an enlarged cross-sectional view of a main part of the impact tool shown in FIG. 1, showing a state in which a tip tool is separated from a tool holder. FIG.
[Explanation of symbols]
10: Handle portion, 20: Motor housing, 30: Gear housing, 30A: Support member, 31: First gear, 32: Intermediate shaft, 33: Second gear, 34: Cylinder, 34a; Cylinder recess, 35: Tip tool 35a: groove, 40: motion conversion member, 42: piston, 43: striking element, 44: air chamber, 45: meson, 50: tool holder, 51: tool sleeve, 52: spring, 53: first through hole, 54: Sphere as a first locking member, 55: First fixing member, 56: First operation sleeve, 56A: Small diameter part, 63: Second through hole, 64: Sphere as a second locking member, 65: Second Fixing member, 66: second operation sleeve, 66A: large diameter portion

Claims (4)

An electric motor that generates a rotational driving force, a cylinder that can be rotated by the rotational driving force from the electric motor, a motion conversion unit that converts the rotational driving force from the electric motor into a reciprocating motion, and a A piston portion that generates a striking force by reciprocating motion; a tool holder that is detachably connected to the tip of the cylinder and that holds the tip tool; and a striking transmission portion that transmits the striking force from the piston portion to the tip tool. In the impact tool,
A tool sleeve for interiorizing the tip tool;
A cylinder engagement / release mechanism for maintaining or releasing the engagement between the tool sleeve and the cylinder tip;
A tool engagement / release mechanism for maintaining or releasing engagement between the tool sleeve and the tip tool;
A spring located between the tool engagement / release mechanism and the cylinder engagement / release mechanism and provided concentrically on the outer periphery of the tool sleeve, the spring engaging the tool engagement / release mechanism; Is biased in the tip direction to maintain the engagement between the tool sleeve and the tip tool, and the cylinder engagement / release mechanism is biased in the direction opposite to the tip direction to engage the cylinder and the tool sleeve. An impact tool characterized by maintaining a combined state. A first through hole and a second through hole are formed in the tool sleeve, and a recess is formed in the outer periphery of the cylinder.
The cylinder engaging / releasing mechanism is urged in a direction opposite to the tip tool by the first locking member arranged to be engageable with the recess in the first through hole and the one spring. A first fixing member that contacts the outer periphery of the first locking member so as to fix the engagement between the first locking member and the recess, and is connected to the first fixing member and is movable in the axial direction of the sleeve A first operating sleeve, and releasing the engagement state between the cylinder and the tool sleeve by moving the first operating sleeve in the distal direction.
The tool engagement / release mechanism includes a second locking member disposed in the second through-hole so as to be engageable with the tip tool inserted into the tool sleeve, and the one spring in the tip direction. A second fixing member that contacts the outer periphery of the second locking member so as to fix the engagement between the second locking member and the tip tool, and the tool sleeve connected to the second fixing member. A second operating sleeve that is movable in the axial direction of the first tool, and disengaging the tip tool from the tool sleeve by moving the second operating sleeve in the opposite direction. The impact tool according to claim 1. At least two of the first through holes are formed in the tool sleeve, and the first locking members are provided in the first through holes, respectively, and the recesses correspond to the first locking members. A tool holder for an impact tool according to claim 2, wherein the first fixing member is provided. The first operating sleeve and the second operating sleeve are arranged concentrically with the tool sleeve, and the second operating sleeve has a diameter close to the first operating sleeve close to the tip side of the second operating sleeve. The first operating sleeve has a small diameter portion in which the diameter of the portion close to the second operating sleeve is smaller than the portion on the opposite side to the tip side of the first operating sleeve; The small-diameter portion is sized to be housed in the large-diameter portion, and the one spring is disposed concentrically in a space defined by the large-diameter portion and the small-diameter portion. The tool holder of the impact tool according to 2.

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