JP2003071735A - Tool attaching mechanism for rotary tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tool attaching mechanism for a rotary tool surely preventing a connecting pin from coming off even a heavy load acts on the connecting pin connecting an anvil and a tool to each other by eccentric load generating due to centrifugal force in high speed rotation. SOLUTION: A square pillar part formed on the anvil 6 of the rotary tool is inserted in a square hold formed in a base part of the tool 10 and the connecting pin 15 is fitted in through holes 12, 14 passing through the anvil 6 and the tool 10 in a direction perpendicular to a rotation axis. An O-ring 17 is put on an outer circumference surface of the tool 10 to cover both end parts of the through hole 14 and a wide ring 18 is put over the O-ring 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary tool such as an impact wrench driven by an electric motor, an air motor or the like, and in particular, a tool such as a box socket or the like can be attached to and detached from an anvil portion rotatably driven by a motor or the like. A mounting mechanism for a tool to be mounted.

[0002]

2. Description of the Related Art In a rotary tool such as an impact wrench, the rotary power of an electric motor, an air motor, etc. is rotationally driven through a reduction mechanism or a hammer mechanism, and a socket is attached to the anvil portion protrudingly arranged at the tip of the tool. Install tools such as, and perform bolt tightening work. The tool is configured to be attachable to and detachable from the anvil portion so that tools having different shapes or sizes can be exchanged and used according to work. In conventional tools, the prismatic anvil part is fitted into the square hole formed in the base of the tool such as a socket to transmit the rotation of the anvil to the tool side, preventing axial removal. As a result, a connecting pin is inserted into a through hole formed in a direction orthogonal to the rotation axis so as to penetrate the tool and the anvil portion. To prevent the connecting pin from slipping out of the through hole, O-rings are attached to the outer peripheral surface of the tool to close both ends of the through hole in which the connecting pin is fitted so that the connecting pin does not slip out of the hole.

[0003]

However, the centrifugal force generated when the anvil is rotated at a high speed causes an eccentric load to act on the connecting pin, and a large load acts in the direction in which the connecting pin comes out of the through hole. When the O-ring that covers the outer circumference is pressed and the load that exceeds the elastic force of the O-ring is applied, the O-ring expands, the O-ring disengages from the end of the connecting pin, and the pin slips out from the side of the O-ring. It will happen. If the connecting pin is used with the through hole removed, the tool such as the socket will come off the anvil, and the work using the rotary tool will not be possible.

According to the present invention, in a rotary tool such as an impact wrench, even if a large eccentric load acts on the connecting pin connecting the anvil and the tool due to the eccentric load due to centrifugal force during high speed rotation, the connecting pin It is an object of the present invention to provide a tool mounting mechanism for a rotary tool capable of reliably preventing the tool from coming off from the through hole.

[0005]

In order to solve the above-mentioned problems, the present invention inserts a prism portion formed in an anvil of a rotary tool into a square hole formed in a base portion of the tool, and makes the anvil and the tool an axis of rotation. A connecting pin is fitted into a through hole penetrating in a direction orthogonal to each other, and an O ring is attached to the outer peripheral surface of the tool so as to cover both ends of the through hole. A wide elastic ring is stacked and attached to prevent the connecting pin from coming off.

According to a second aspect of the present invention, an elastic ring mounted on the outer peripheral surface of the tool so as to cover both ends of the through hole has a semi-circular cross section on the inner peripheral surface of the band-shaped ring wider than the width of the through hole. It is characterized in that a circular semicircular ring is integrally formed by protruding in the center direction.

Further, according to the invention of claim 3, an elastic ring mounted on the outer peripheral surface of the tool so as to cover both ends of the through hole,
It is characterized in that the outer peripheral side is wide and the inner peripheral side is narrow. The invention of claim 4 is characterized in that a flat surface is formed on the inner diameter side of the elastic ring according to claim 3 so as to come into contact with the end of the connecting pin.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below based on the embodiments shown in the drawings. FIG. 1 shows the outer shape of a rotary tool on which a tool is mounted by the mounting mechanism of the present invention. In this embodiment, an attachment mechanism is implemented in an air impact wrench driven by compressed air as an example of the rotary tool 1. The impact wrench 1 is provided with a housing 2 which houses a rotary drive mechanism and a grip portion 3 for gripping a tool, and is connected to a compressed air source via a plug 4 attached to a rear end portion of the grip portion 3. Trigger lever 5 provided at the base of grip part 3 for supplying compressed air
Is supplied to the drive mechanism, and the drive mechanism is driven by compressed air pressure. A front end portion of an anvil 6 which is rotationally driven by a drive mechanism is exposed in front of the housing 2, and a socket 10 as a tool is attached to the anvil 6.

As shown in FIG. 2, an anvil 6 is housed in the housing 2 via an air motor 7 which is rotationally driven by compressed air and a hammer 8 which is rotated by the air motor 7.
An impact mechanism 9 for rotationally driving the shock absorber is coaxially arranged and housed, and a tip end of the anvil 6 which is rotationally driven by the impact mechanism 9 is arranged so as to project forward from the tip end of the housing 2. The tip of the anvil 6 is formed with a connecting portion 11 formed in a quadrangular prism shape for transmitting a rotational force to the tool, and a through hole 12 is bored in the connecting portion 11 in a direction orthogonal to the rotation axis of the anvil 6. ing.

As shown in FIGS. 3 and 4, the socket 10 mounted on the connecting portion 11 of the anvil 6 has a square hole 13 formed on the base side and extending parallel to the rotation axis. The connecting portion 11 of the anvil 6 is fitted in the hole 13, and the socket 10 has a through hole 12 on the anvil 6 side in a state where the socket 10 is connected to the anvil 6.
And a through hole 14 continuous with the through hole 12 is formed.
A connecting pin 15 is fitted in the sockets 14 and 14 to connect the socket 10 to the anvil 6. Further, an annular groove 16 is formed on the outer peripheral surface of the socket 10 so as to intersect with the open end of the through hole 14 on the outer peripheral side.
6 is opened at the bottom of the groove. The O-ring 17 is housed in the annular groove 16, and a wide ring 18 is attached to the outer peripheral surface of the socket 10 so as to cover the O-ring 17.

Both ends of the connecting pin 15 fitted in the through holes 12 and 14 are fitted in the annular groove 16 at both ends.
It is elastically pressed by the ring 17 and prevents the connecting pin 15 from coming out of the through hole 14 due to the load due to the centrifugal force. Moreover, even if a larger load acts on the connecting pin 15 and the O-ring 17 is deformed,
A wide ring 1 mounted on the outer peripheral surface of the socket 10.
Since 8 acts to press the outer peripheral surface of the O-ring 17 elastically and to suppress the deformation of the O-ring 17, the connection from the inside of the through hole 14 can be performed without changing the shape of the socket that has been conventionally used. It is possible to reliably prevent the pin 15 from coming off. Therefore, the socket 10 attached to the anvil 6 does not come off, and the work can be performed safely. The socket 10 can be replaced by removing the connecting pin 15 from the through holes 12 and 14 while the wide ring 18 and the O-ring 17 are displaced from the annular groove 16 along the axial direction on the outer peripheral surface of the socket 10. it can.

5 to 7 show another embodiment of the tool mounting mechanism of the present invention. In the above-described embodiment, the O-ring 17 that comes into contact with the end of the connecting pin and the wide ring 18 that is mounted on the outer peripheral side of the O-ring 17 are separately configured. However, the elasticity of the embodiment shown in FIG. In the ring 20, a semicircular ring 22 having a semicircular cross section is formed on the inner peripheral surface of a wide band-shaped ring 21.
Is integrally formed. Both rings 2 like this
By integrally forming 1 and 22, the socket 10 can be attached and detached more easily. In the embodiment shown in FIG. 5A, the elastic ring 20 is attached to the socket 10 having an existing shape in which the annular groove 16 for accommodating the O-ring is formed on the outer peripheral surface of the socket 10, and the semicircular ring 22 is used. Is housed in the annular groove 16 and presses the end of the connecting pin 15 to prevent it from coming off. In the embodiment of FIG. 5B, the strip-shaped ring 21 of the elastic ring 20 is formed on the outer peripheral surface of the socket 10.
The annular ring 16a for accommodating the portion is formed, and the elastic ring 20 is formed.
The band-shaped ring 21 is housed in the annular groove 16a so that the elastic ring 20 does not protrude to the outer peripheral surface of the socket 10, and the elastic ring 20 is prevented from being damaged or coming off. In addition, the embodiment shown in FIG. 5C has a wide band-shaped ring 21 of the elastic ring 20.
The annular groove 16a for accommodating the part is formed to have a depth smaller than the thickness of the band-shaped ring 21 part so that a part of the band-shaped ring 21 protrudes from the annular groove 16a.
Since the attaching / detaching operation can be performed relatively easily and the protruding portion is small, it is possible to prevent the elastic ring 20 from being damaged.

In the embodiment shown in FIG. 6, the elastic ring has a cross-sectional shape with a flat outer peripheral surface, and the width of the outer peripheral portion is for accommodating an O-ring formed on the outer peripheral surface of the existing socket 10. The elastic ring is formed to have almost the same width as the annular groove 16, and the elastic ring is accommodated in the annular groove 16 for accommodating the O-ring of the existing socket 10.
In the embodiment of (a), the elastic ring 23 has a substantially trapezoidal cross section, and in the embodiment of FIG. 6 (b), the elastic ring 24 has a substantially D-shaped cross section.
Both 3 and 24 are accommodated in the annular groove 16 formed in the existing socket 10, the existing socket can be used, and the outer peripheral portions of the elastic rings 23 and 24 project from the outer peripheral surface of the socket 10. First, prevent the elastic ring from being damaged or coming off. Furthermore, in the embodiment shown in FIGS. 6C and 6D, the elastic ring 23,
Since the outer peripheral portion of 24 is mounted so as to slightly project from the annular groove 16, the socket 10 can be relatively easily attached and detached, and since the projecting portion is small, the elastic rings 23 and 24 are prevented from being damaged. Is possible.

In the embodiment shown in FIG. 7A, the elastic ring 2 is used.
The width of the elastic ring 25 is made wider than the width of the through hole 14, and a flat surface 26 is formed on the inner peripheral portion of the elastic ring 25 in contact with the connecting pin 15.
An annular groove 1 wider than the through hole 14 formed on the outer peripheral surface of the
It is housed in 6a. According to this, since the cross-sectional area of the elastic ring 25 can be increased, the tightening force for preventing the connecting pin 15 from coming off can be increased. Further, since the flat portion 26 is formed at the contact portion with the connecting pin 15, it is possible to prevent the connecting pin 15 from pushing the elastic ring 23 and coming out of the side of the ring. Further, as shown in FIG. 7 (b), by mounting the outer peripheral portion of the elastic ring 25 so as to slightly project from the annular groove 16a, the socket 10 can be attached and detached relatively easily, and the protruding Since the portion is small, it is possible to prevent the elastic ring 25 from being damaged.

[0015]

As described above, according to the present invention, both ends of the through hole 14 into which the connecting pin 15 is fitted are covered from the outer peripheral side of the connecting pin 15 which penetrates the anvil 6 and the tool 10. Since the O-ring 17 is mounted on the O-ring 17 and the wide ring 18 is mounted on the outer peripheral side of the O-ring 17, the tightening force for suppressing the load of the connecting pin 15 in the pull-out direction can be increased. It is possible to prevent the connecting pin 15 from coming out of the through holes 12 and 14 due to the centrifugal force. Further, since the elastic ring 20 is formed by integrally molding the semi-circular ring 22 on the inner peripheral surface side of the wide band-shaped ring 21, the workability of the attaching / detaching operation of the socket 10 is not impaired and the connecting pin 15 is not damaged. It is possible to reliably prevent slipping out.
Furthermore, the elastic rings 23 and 24 are formed in a cross section having a wide outer peripheral portion and a narrow inner peripheral portion, and the annular groove 1 of the existing socket 10 is
Since it can be accommodated in 6, it is possible to obtain a sufficiently large tightening resilience to reliably prevent the connecting pin 15 from slipping out, and use it as it is without changing the shape of the existing socket already used in the field. It is possible. Further, by forming the flat surface 26 that abuts the end of the connecting pin 15 on the inner peripheral portion of the elastic ring 25, the flat surface 26 can surely press the upper end surface of the connecting pin 15, and the connecting pin 15 It is possible to prevent the elastic ring 25 from being pushed away and coming out from the side.

[Brief description of drawings]

FIG. 1 is an external view of an air impact wrench in which the socket mounting mechanism of the present invention is implemented.

FIG. 2 is a partial sectional view of the same embodiment as FIG.

FIG. 3 is an enlarged cross-sectional view of the main part of FIG.

FIG. 4 is an exploded perspective view showing the configuration of the main part of the present invention.

5A to 5C are sectional views showing another embodiment of the elastic ring.

6A to 6D are sectional views showing another embodiment of the elastic ring.

7A and 7B are cross-sectional views showing still another embodiment of the elastic ring.

[Explanation of symbols]

1 rotary tool (air impact wrench) 6 anvil 10 socket 11 Connection 12 through holes 13 square hole 14 through holes 15 connecting pin 16 annular groove 17 O-ring 18 wide ring 20 elastic ring 21 banded ring 22 half circle ring 23 Elastic Ring 24 elastic ring 25 elastic ring 26 Flat surface

Continued front page    (72) Inventor Shinji Hanada             6-6 Hakozakicho, Nihonbashi, Chuo-ku, Tokyo             Cos Co., Ltd.

Claims (4)

[Claims] 1. A prismatic portion formed on an anvil of a rotary tool such as an impact wrench is inserted into a square hole formed in a base portion of the tool, and the anvil and the tool are connected to a through hole penetrating in a direction orthogonal to a rotation axis. Insert a pin, attach an O-ring to the outer peripheral surface of the tool so as to cover both ends of the through hole, and attach an elastic ring having a width wider than the width of the O-ring over the O-ring. A tool mounting mechanism for a rotary tool, characterized in that the connecting pin is prevented from coming off. 2. A prismatic portion formed on the anvil of a rotary tool such as an impact wrench is inserted into a square hole formed at the base of the tool, and the anvil and the tool are connected to a through hole penetrating in a direction orthogonal to the axis of rotation. An elastic ring integrally formed by inserting a pin and projecting a semicircular ring having a semicircular cross section in the center direction on the inner peripheral surface of a band-shaped ring wider than the width of the through hole is provided at both ends of the through hole. A tool mounting mechanism for a rotary tool, which is mounted on the outer peripheral surface of the tool so as to cover it. 3. A prismatic portion formed on an anvil of a rotary tool such as an impact wrench is inserted into a square hole formed in a base portion of the tool, and the anvil and the tool are connected to a through hole penetrating in a direction orthogonal to a rotation axis. It is characterized in that a pin is fitted and an elastic ring formed so that the outer peripheral side is wide and the inner peripheral side is narrow is installed in an annular groove formed on the outer peripheral surface of the tool so as to cover both ends of the through hole. Tool mounting mechanism for rotating tools. 4. The tool mounting mechanism for a rotary tool according to claim 3, wherein a flat surface that abuts an end of the connecting pin is formed on an inner peripheral surface of the elastic ring having a narrow width.