JP3939138B2 - Tightening tool - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tightening tool for tightening a bolt held by, for example, a bolt holding mechanism.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, when a bolt or the like is tightened with a rotary tightening tool, a technique for performing a tightening operation by decelerating the output of a drive motor with a planetary gear or the like is known, for example, as disclosed in JP-A-9-239672. .
[0003]
[Problems to be solved by the invention]
However, for example, when a bolt holding mechanism is provided at the tip of the tightening tool and the bolt is fed to the bolt holding mechanism and the socket that is built into the tightening tool is advanced to tighten the bolt, After fitting the socket to the bolt head held by the holding mechanism, if the socket rotation is too high in the series of flow until tightening work, the socket fits into the bolt head In some cases, such as a bolt falling down or falling, it was insufficient to reduce the planetary gear alone.
Also, if the rotation of the socket is lowered in a series of flows, the bolt can be prevented from dropping or tilting when the socket is fitted to the bolt head, but the bolt tightening operation takes time. There was a problem that work efficiency deteriorated.
[0004]
Therefore, the present invention prevents a problem that the bolt falls, falls, or causes poor tightening when the bolt is held at the tip of the tightening tool and the work efficiency is improved. The purpose is to prevent the decrease.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, the socket shaft is moved forward by a drive source while being rotated via a rotation speed variable mechanism, and the socket at the tip of the socket shaft is fitted to the bolt head, and then the bolt is tightened. In the tightening tool, the rotation speed variable mechanism is provided rotatably on the differential shaft inner coupled to the output shaft of the speed reduction mechanism and having a screw portion formed on the outer periphery thereof, and the outer case of the tightening tool. A cylindrical differential shaft outer having a thread groove formed in an inner peripheral portion, the differential shaft inner being inserted into a cylinder of the differential shaft outer, and an outer peripheral screw portion being an inner portion of the differential shaft outer. Engaging with the peripheral screw groove, oil is sealed in the cylinder of the differential shaft outer, and the socket shaft is connected to the distal end side of the differential shaft inner, and the drive source and the socket are connected to each other. Between the sockets are bolts The differential shaft outer rotates at a low speed due to the action of the oil in the cylinder until the bolt is tightened until the bolt is tightened. The outer rotates together to make the socket shaft rotate faster .
[0006]
In this way, by rotating the socket shaft at a low speed until the socket is fitted to the bolt head and advanced to the tightening position, the bolt falls or is tilted and chucked when the socket is fitted. There is no problem, and the tightening work can be made more efficient by rotating the socket shaft at a high speed when tightening is started thereafter.
[0007]
In the present invention, as the rotation speed variable mechanism, a differential shaft inner coupled to the output shaft of the speed reduction mechanism and having a screw portion formed on the outer peripheral portion, and an inner case rotatably provided on the outer case of the tightening tool. A cylindrical differential shaft outer with a thread groove formed in the peripheral portion is provided, the differential shaft inner is inserted into the cylinder of the differential shaft outer, and the outer peripheral screw portion is inserted into the inner peripheral screw groove of the differential shaft outer. In addition, the oil was sealed in the cylinder of the differential shaft outer, and the socket shaft was connected to the tip side of the differential shaft inner.
[0008]
Initially, the differential shaft inner rotates in the cylinder of the differential shaft outer and moves forward by the action of the screw portion, and the differential shaft inner moves forward to the inner end of the differential shaft outer and moves to the inner wall. When abutting, the differential shaft inner and the differential shaft outer rotate together.
By doing so, the initial rotation of the differential shaft inner is decelerated by the action of the oil and is rotated at a low speed, and the socket shaft connected to the differential shaft inner is also rotated at a low speed. Thereafter, when the differential shaft inner comes into contact with the differential shaft outer and starts to rotate integrally, the differential shaft inner rotates at a high speed, and the socket shaft connected to the differential shaft inner also rotates at a high speed.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the accompanying drawings.
Here, FIG. 1 is an explanatory view of a tightening tool according to the present invention, FIG. 2 is an explanatory view of a speed reduction mechanism, FIG. 3 is a cross-sectional view taken along line AA of FIG. 5 is an action diagram.
[0010]
In the tightening tool 1 according to the present invention, when the bolt B held by the bolt holding mechanism 2 at the tip of the tool is tightened by the socket 3, the bolt B is prevented from dropping or tilting. Can be performed efficiently.
[0011]
That is, a cassette 4 that accommodates a large number of bolts B is detachably attached to a lower portion of the bolt holding mechanism 2 of the tightening tool 1, and the bolts B aligned in a vertical row are moved downward by the springs 5 of the cassette 4. The uppermost bolt B is fed to the upper side by one pitch, held by the holding claw 6 of the bolt holding mechanism 2, and pressed and positioned by the pressing positioning member 7 above.
[0012]
The socket 3 is attached to the tip of a socket shaft 10 that can be moved forward and backward in the outer case 8 of the tightening tool 1, and the socket shaft 10 is connected to a rotation speed variable mechanism 11 and is rotated. The variable speed mechanism 11 is connected to a speed reduction mechanism 13 of a drive motor 12 as a drive source.
Then, at the initial stage when the socket 3 is in the retracted position by the rotation speed variable mechanism 11, the socket shaft 10 moves forward while rotating at a low speed, and the socket 3 is fitted to the bolt B head to start tightening. At the time, the socket shaft 10 is rotated at a high speed.
[0013]
As shown in FIGS. 2 and 3, the speed reduction mechanism 13 includes a plurality of planetary gears 15 that mesh with the teeth 14 g of the drive shaft 14 of the drive motor 12, and a rotation that supports the rotation shaft 16 of the planetary gear 15. The rotating plate 17 includes a free rotating plate 17 and an output shaft 18 having a square cross section projecting forward from the rotating plate 17, and the planetary gear 15 meshes with the inner teeth of the ring gear 19 fixed to the outer case 8 side. is doing.
[0014]
As shown in FIG. 4, the rotation speed variable mechanism 11 is slidably fitted to a cylindrical differential shaft outer 21 that is rotatably supported by the outer case 8 and an output shaft 18 of the speed reduction mechanism 13. A differential shaft inner 22 is provided. Oil is sealed in the cylinder H of the differential shaft outer 21, and a screw portion n is provided on the outer peripheral portion of the large-diameter portion 22 b of the differential shaft inner 22. In addition, a thread groove m is formed in the inner peripheral portion of the differential shaft outer 21.
The screw portion n of the differential shaft inner 22 is engaged with the screw groove m of the differential shaft outer 23.
[0015]
Further, the shaft portion 22j of the differential shaft inner 22 protrudes forward from the cylindrical portion of the differential shaft outer 21, and an intermediate portion of the shaft portion 22j is inserted so that the shaft insertion member 23 can rotate and can be pressed forward. At the same time, the socket shaft 10 is connected to the protruding end portion of the shaft portion 22j.
A spring 25 is interposed between the shaft insertion member 23 and the spring seat 24 of the outer case 8, and when the differential shaft inner 22 advances, the spring 25 contracts and the socket shaft 10 advances. Like to do.
[0016]
A lock claw 26 and a lock pin 27 that are operated when the differential shaft inner 22 reaches the forward stroke end are provided below the differential shaft outer 21, and the differential shaft inner 22 is connected to the forward stroke end. At this point, the lock claw 26 is locked by the lock pin 27, so that the drive motor 12 is rotated reversely so that the differential shaft inner 22 returns to the original position.
[0017]
The operation of the tightening tool 1 as described above will be described with reference to FIG.
As shown in FIG. 5A, when the bolt B placed on the holding claw 6 of the bolt holding mechanism 2 is pressed and positioned downward by the pressing positioning member 7, the drive motor 12 is driven. The rotation of the drive shaft 14 is decelerated by the speed reduction mechanism 13 and the differential shaft inner 22 fitted to the output shaft 18 starts to rotate.
[0018]
When the differential shaft inner 22 starts to rotate by the action of the oil in the cylinder H of the differential shaft outer 21, differential shaft outer 21 start around rotation brought, also, the differential shaft inner 22 is threaded portion n The forward movement is gradually started by the engagement of the screw groove m. Then, as shown in FIG. 5B, the socket shaft 10 moves forward while the spring 25 is contracted, and the socket 3 is fitted to the head of the bolt B. At this time, the tip of the bolt B has not advanced to the position of the tightened portion Y.
[0019]
When the socket 3 further advances, the pressing positioning member 7 is pushed by the front surface of the socket 3 and retracts upward while contracting the spring 28, so that the tip of the bolt B reaches the position of the tightening portion Y. When moved, the front surface of the large-diameter portion 22b of the differential shaft inner 22 is brought into contact with the front inner wall surface of the differential shaft outer 21 as shown in FIG.
[0020]
In addition, as described above, when the front surface of the large-diameter portion 22b of the differential shaft inner 22 comes into contact with the front inner wall surface of the differential shaft outer 21, the tip of the bolt B reaches the position of the tightened portion Y. The differential shaft inner 22 and the differential shaft outer 21 rotate integrally from this point, and the rotation of the socket shaft 10 is the rotation of the output shaft 18 of the speed reduction mechanism 13. To match.
That is, it rotates at a low speed until the front end of the bolt B reaches the position of the tightening portion Y, and is automatically switched to a high speed rotation from the time when the front end of the bolt B reaches the position of the tightening portion Y. Tightening work can be performed.
[0021]
When the tightening operation is completed, the lock claw 26 is locked by the lock pin 27, the differential shaft inner 22 is returned to the original position, and the next bolt B is held by the holding claw 6 of the bolt holding mechanism 2. Although the operation is repeated, since the rotation is performed at a low speed until the socket 3 is fitted to the head of the bolt B and tightening is started, problems such as dropping, tilting, and poor tightening of the bolt B can be prevented.
In addition, since the tightening work is performed at a high speed thereafter, the tightening work is efficiently performed.
[0022]
The present invention is not limited to the above embodiment. What has substantially the same configuration as the matters described in the claims of the present invention and exhibits the same operational effects belongs to the technical scope of the present invention.
[0023]
【The invention's effect】
As described above, the tightening tool according to the present invention reduces the rotation of the socket shaft between the drive source and the socket until the socket is fitted to the bolt head, and the socket is fitted to the bolt head and tightened. Since the rotation speed variable mechanism for increasing the rotation speed of the socket shaft is provided at the time of starting the operation, there is no problem that the bolts are dropped or tilted and chucked, and the efficiency of the tightening work It became possible to plan.
As the rotation speed variable mechanism, it is preferable that the screw portion and the screw groove of the differential shaft inner and the differential shaft outer are engaged with each other so that oil is sealed in the cylinder of the differential shaft outer.
[Brief description of the drawings]
FIG. 1 is an explanatory view of a tightening tool according to the present invention. FIG. 2 is an explanatory view of a speed reduction mechanism. FIG. 3 is a cross-sectional view taken along line AA in FIG. ] Action diagram [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Tightening tool, 2 ... Bolt holding mechanism, 3 ... Socket, 8 ... Outer case, 10 ... Socket shaft, 11 ... Rotation speed variable mechanism, 12 ... Drive motor, 13 ... Deceleration mechanism, 18 ... Output shaft, 21 ... Actuating shaft outer, 22... Differential shaft inner, n... Threaded portion, m.

Claims (1)

A tightening tool for advancing the socket shaft through a rotation speed variable mechanism by a drive source, and fitting the socket at the tip of the socket shaft to the bolt head, and then tightening the bolt,
The variable rotation speed mechanism includes a differential shaft inner that is coupled to the output shaft of the speed reduction mechanism and has a screw portion formed on the outer peripheral portion thereof, and is rotatably provided on the outer case of the tightening tool and has a screw groove formed on the inner peripheral portion thereof. The differential shaft inner is inserted into the cylinder of the differential shaft outer, and the outer peripheral screw portion meshes with the inner peripheral screw groove of the differential shaft outer. The oil is sealed in the cylinder of the differential shaft outer, the socket shaft is connected to the tip end side of the differential shaft inner, and the socket is a bolt between the drive source and the socket. The differential shaft outer rotates at a low speed due to the action of the oil in the cylinder until it is fitted to the head and moved forward to the tightening position. The shaft outer rotates integrally to increase the socket shaft rotation speed. Tightening tool, wherein the door.

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