JPH0460791B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides two methods for adjusting and fixing the axial clearance.
Regarding a tightening device for tightening and fixing a double nut consisting of two nuts, more specifically, it is a device that positions an adjusting nut at a predetermined position in the axial direction, and then tightens and locks the fixing nut in this state. This invention relates to a double nut tightening device that can be tightened automatically.

[Background of the invention]

2. Description of the Related Art Mechanisms in which a member rotatably fitted to a shaft, such as a lever, is held using a double nut while maintaining an appropriate axial clearance are used in various devices. Conventionally, such double nuts have been manually tightened. To do this, position the adjusting nut so that there is a predetermined axial clearance so that the rotating member such as the lever can rotate smoothly. Next, while holding the adjusting nut so that it does not move, tighten the fixing nut. This is done through the process of tightening and locking. Therefore, it becomes very complicated to perform such work reliably by hand, and it is also difficult to reliably position the adjusting nut and lock by tightening the fixing nut.

In addition, especially regarding the positioning of the adjusting nut, in many cases a method is used in which the adjusting nut is returned so that there is a predetermined axial clearance and a predetermined clearance is provided between it and the rotating member. There are problems such as variations in the axial clearance due to variations in thickness and variations in the return amount of the adjusting nut.

[Purpose of the invention]

In view of the problems of double nut tightening work, the present invention makes it possible to position the adjusting nut so that there is always a constant axial clearance despite variations in the thickness of the rotating member, and It is an object of the present invention to provide a double nut tightening device that can automatically position the adjusting nut and tighten the fixing nut automatically, quickly and reliably, and to enable automatic assembly.

[Summary of the invention]

The gist of the present invention is to provide an adjustment nut rotation device that includes a jig stand that holds a screw shaft non-rotatably, and a positioning reversing device that rotates the once tightened adjustment nut in the return direction by a predetermined amount and then stops the adjustment nut. a fixing nut tightening device that operates after the adjusting nut turning device is stopped to tighten the fixing nut and lock the adjusting nut; and an adjusting nut turning device and a fixing nut tightening device. A socket is provided at each end facing the jig table and elastically supported in the axial direction, and an adjustment nut rotation device and a fixing nut tightening device are supported so as to move toward and away from the jig table at the same time. In particular, the rotating shaft of the adjusting nut rotating device is hollow, has a socket for rotating the adjusting nut at its tip, and has a fixing nut rotating device. A drive shaft of the nut tightening device is provided passing through the center of the rotation shaft, and a fixing nut driving socket is provided at the tip of the drive shaft and inside the adjustment nut rotation socket. The main points of this report are as follows.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described based on the drawings.

Referring to FIG. 1, an example of a double nut mechanism to which the present invention is applied will first be described.

In this embodiment, a pair of levers C and D are rotatably fitted in contact with the flange B of the shaft A.
By locking the adjusting nut E provided at the other end with a predetermined axial clearance by tightening the fixing nut F, which is a cap nut, the levers C and D can be rotated independently and smoothly. is possible. Here, the hexagonal shape of the fixing nut F is set to be slightly smaller than the width across flats of the adjusting nut E, so that the fixing nut can rotate within the width across flats of the adjusting nut.

Next, to explain the double nut tightening device described above, a support body 2 is provided along two guide rails 1 so as to be moved up and down by a vertical movement device such as a cam mechanism, and an adjustment nut rotation is attached to the support body 2. The adjusting nut turning device 3 is attached to the adjusting nut turning device 3.
A fixing nut tightening device 4 is provided passing through the inside of the holder.

The adjusting nut turning device 3 and the fixing nut tightening device 4 support a work such as a lever fixed with a double nut while maintaining an axial clearance, and serve as a jig stand that holds this screw shaft A non-rotatably. These jig stands are arranged to face each other, and are transported after temporarily assembling the adjusting nut E and the cap nut F, which is a fixing nut, in a previous process as part of an automatic assembly device (not shown).

The adjusting nut rotating device 3 has a hollow shaft 6 rotatably supported by a bearing 5 on the support body 2, and has a hexagonal hole 7 at the lower end of the hollow shaft 6 into which the adjusting nut E is fitted. A socket 8 is mounted integrally in the rotational direction and movable in the axial direction by a key 9, and the socket 8 is further prevented from coming off by a cover 10 fixed to the hollow shaft 6, and a spring 1 is attached to the socket 8.
1 is biased downward.

Further, a cylindrical body 1 is mounted on the outside of the hollow shaft 6 by a bearing 12.
A one-way clutch 14 and a friction clutch 15 are interposed between the hollow shaft 6 and the cylindrical body 13 to form a reversing device for positioning the adjusting nut E.

The one-way clutch 14 rotates freely in the nut tightening direction, and is attached so as to integrally connect the hollow shaft 6 and the cylindrical body 13 in the opposite direction, the nut returning direction.

The friction clutch 15 has a facing 17 screwed to the end of the cylindrical body 13.
A pressure plate 19 having a facing 18 that faces and presses against the hollow shaft 6 is fitted onto the hollow shaft 6 so as to be movable in the axial direction, and is disposed between the pressure plate 19 and a spring receiver 20 provided behind the pressure plate 19. The facing 1 is biased by the provided spring 21, and the facing 1 is generated by the elastic force of the spring 21.
Power is transmitted by the frictional force of 7 and 18, and if the load becomes too large, it will slip at a predetermined torque. This reversing device is driven by a pinion 22 screwed and fixed to the cylinder 13, and the support 2
A rack 25 provided on a piston rod 24 of an air cylinder 23 attached via a bracket 16 meshes with this pinion 22, and the operation of the air cylinder 23 causes the cylinder 13 to move forward and backward by a predetermined angle. It's becoming like that.

The fixed nut tightening device 4 has a rotary shaft 31 which is rotatably supported by a bearing metal 30 and inserted into the center of the hollow shaft 6. A square rod portion 32 is formed at the lower end of the rotary shaft 31, and the above-mentioned Inside the socket 8 of the adjusting nut E, a socket 34 having a hexagonal hole 33 that fits into the fixing nut F is connected to the square rod portion 32.
It is slidably fitted in the axial direction.

In this socket 34, a pin 35 provided on the socket 34 is inserted into an elongated hole 36 of the square rod portion 32, and a spring provided between the socket 34 and a thrust collar 37 on the rotating shaft 31 side at the upper part of the socket 34 is inserted. 38 urges the socket 34 downward, and the lower end of the elongated hole 36 restricts the lower limit position of the socket 34. Further, a known screw tightening device 40 is mounted on the mounting base 39 on the upper part of the support body 2, and a drive shaft 41 of this screw tightening device 40 is connected to the rotating shaft 31 via a joint 42.

The operation of the double nut tightening device having the above structure will be explained. The temporarily assembled work is transferred and stopped below the double nut tightening device of the present invention. Next, first, the adjusting nut rotating device 3 and the fixing nut tightening device 4 are lowered together with the support body 2 by the vertical movement device, and the hexagonal hole 7 of the socket 8 of the adjusting nut rotating device 3 is connected to the adjusting nut E. The hexagonal holes 33 of the sockets 34 of the fixing nut tightening device 4 are fitted into the fixing nuts F, respectively.

If the direction of the hexagonal hole does not match the direction of the nut and the socket and nut do not fit, use sockets 8 and 3.
4 retreats upward against the urging force of the springs 11, 38, the socket rotates as described later, and when the direction of the hexagonal hole matches the direction of the nut, it descends and is fitted. At this time, the rack 25 is in the retracted position, and the cylinder body 1 is moved forward by a predetermined stroke by the operation of the air cylinder 23.
3 by a predetermined amount in the nut tightening direction. At this time, the one-way clutch 14 becomes free, so
The pinion 22 transmits power to the hollow shaft 6 and the socket 8 via the friction clutch 15, and is connected to the adjusting nut E.
The socket 8 and the adjusting nut E are fitted together, and the adjusting nut E is rotated in the tightening direction. Then, when the adjusting nut E is fully tightened and the rotational load on the socket 8 increases rapidly, the friction clutch 15 slips and from then on, only the cylindrical body 13 simply rotates idly.

Next, the piston rod of the air cylinder 23 moves forward to project the rack 25 by an amount that creates a predetermined axial clearance, contrary to the above, and rotates the cylinder 13 in the nut return direction. Then, at this time, the cylinder body 13 and the hollow shaft 6 are integrally connected by the one-way clutch 14, and power is transmitted without slipping, and the adjusting nut E returns to the position with a predetermined axial clearance. It is held in position by socket 8. When the amount of return is smaller than the amount of rotation in the tightening direction, it can be stopped at a predetermined position by providing an arbitrary switchable stopper (not shown).

Here, when the screw tightening device 40 of the fixing nut tightening device 4 is driven, the socket 34 rotates via the rotating shaft 31, the square bar part 32, and the pin 35, and the socket 34 and the fixing nut F are fitted together. Then, the fixing nut F is tightened. In this case, since the adjusting nut E is held by the socket 8,
Due to the high speed rotation of the socket 34, the fixing nut F
and adjustment nut E are tightened instantly,
To securely and firmly lock the adjusting nut E. When the adjusting nut E is locked and the tightening torque of the fixing nut F reaches the set value, the screw tightening device 40
automatically shuts off, the work cycle ends, the next work is transferred, and the next work cycle begins.

〔Effect of the invention〕

As is clear from the above description, the present invention includes an adjustment nut rotation device 3 that positions the adjustment nut E, and a fixation nut tightening device 4 that tightens the fixation nut. These devices 3,
4 operates continuously, the double nut tightening work can be performed quickly and reliably, and when the adjusting nut turning device 3 is used for positioning, the adjusting nut E is once fully tightened. After being moved, it is returned and positioned with a predetermined axial clearance, so the axial direction is always constant regardless of the temporarily tightened state of the adjustment nut E, variations in the thickness of the rotating levers C and D, etc. A clearance can be determined, and since the fixing nut F is tightened with the adjusting nut E positioned and held in the socket 8, the adjusting nut E can be reliably locked without becoming distorted.

Further, the double nut tightening device of the present invention is suitable for automatic assembly, and when adopted in an automatic assembly machine, great effects can be produced.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of the apparatus according to the present invention, and FIG. 2 is a sectional view taken along the line - in FIG. 3...Adjustment nut rotating device, 4...Fixing nut tightening device, 8, 34...Socket, 14...One-way clutch, 15...Friction clutch, E...Adjustment nut, F...Fixing nut.

Claims (1)

[Scope of Claims] 1. An adjusting nut that has a jig stand that holds the screw shaft non-rotatably, and a reversing device for positioning that rotates the once tightened adjusting nut in the return direction by a predetermined amount to position and fix it. a rotation device; a fixing nut tightening device that operates after the adjustment nut rotation device is stopped to tighten the fixation nut and lock the adjustment nut; and a hollow rotation device for the adjustment nut rotation device. A socket for rotating the adjusting nut is provided at the tip of the shaft facing the jig table and elastically supported in the axial direction, and a drive shaft of the fixing nut tightening device passes through the center of the rotating shaft. a fixing nut drive socket provided at the tip of the drive shaft facing the jig stand and elastically supported in the axial direction inside the adjustment nut rotation socket; A vertical movement device that independently rotatably supports the nut rotation device and the fixing nut tightening device and simultaneously moves the support body up and down so as to move toward and away from the jig table. Double nut tightening device.