JPH0367837B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a nut runner for a stud that can engage and disengage from a stud and screws the stud into a workpiece.

<Prior art> Conventional nut runners for stud bolts screw the stud into the mark with the stud engaged with the socket, and then pull out the stud and socket relative to each other in the axial direction to separate the pair of sockets. The engagement between the socket and stud bolt was released by rotating the female threaded portion formed on the claw of the socket. In order to release the engagement between the male thread of the stud bolt and the female thread of the pair of claws,
There was a problem in that the pair of pawls had to be rotated significantly, and the pair of pawls had to move largely in the radial direction. There was also the problem that the male thread of the stud bolt and the female thread of the pair of threaded members did not tightly engage in the rotational direction. Furthermore, there was a problem in that it was not possible to reliably release the engagement between the stopper and the stud bolt, which were connected to the pair of claws via the pivot pin.

<Objective of the Invention> In order to solve the above-mentioned problems, the object of the present invention is to improve the connection between the female thread of the pair of threaded members and the male thread of the stud bolt even with a small movement of the pair of threaded members in the radial direction. The female thread of the pair of threaded members and the male thread of the stud bolt can be tightly engaged with each other while the stud is in contact with the stopper.
Further, to provide a nut runner for a stud bolt which can surely release the jamming between the stopper and the stud bolt.

<Configuration of the Invention> The nut runner for stud bolts according to the present invention has the following features:
A drive shaft is rotatably connected to the rotation shaft of the nut runner body that moves up and down relative to the stud bolt, and a pair of threaded members that can be contracted and expanded are attached to the drive shaft in the working space formed inside the lower end of the drive shaft. A female thread is formed on the inner periphery of the lower end of the pair of screwing members to be screwed into the male thread of the stud, and the pair of screwing members are rotated in the expansion direction. A spring is inserted between the pair of threaded members, and a stopper that contacts the stud is supported on the drive shaft so as to be rotatable relative to the drive shaft and movable in the relative axial direction. A pin hole is formed in the pair of threaded members, which is provided in a direction perpendicular to the directional movement, and into which the pin is slidably fitted, a ball is held at the lower end of the drive shaft, and a lead is engaged with the ball. A groove is formed on the outer periphery of the pair of threaded members such that the lower end thereof is inclined in a direction away from the rotation center of the drive shaft and in the opposite direction to the thumb screw.

<Examples> Examples of the present invention will be described below based on the drawings.

In FIG. 1, reference numeral 10 denotes a nut runner main body that is movable up and down, and a rotating shaft 11 is rotatably supported on the nut runner main body 10, and is rotatably driven by a drive motor (not shown). Rotating axis 1
1 is fitted with a socket 12 as will be described later, and the stud 13 is screwed into the workpiece W through the socket 12 by rotation of the rotating shaft 11.

A rod 20 is fixed to the rotating shaft 11 coaxially with the rotating shaft 11, and the intermediate shaft 21 is connected to a spline 22.
A pressing spring 24 is interposed between the intermediate shaft 21 and the flange member 23, which is slidably connected to the rotating shaft 11 and integrally connected to the rotating shaft 11.

A first drive shaft 25 is fixed to the intermediate shaft 21, and a washer 26, which is inserted through the rod 20 and comes into contact with the head of the rod 20, is held between the intermediate shaft 21 and the first drive shaft 25. Ball 2 for attachment and detachment to the first drive shaft 25
7 is formed, a cylindrical member 29 is slidably fitted on the outer periphery of the first drive shaft 25, and a locking member 30 provided on the outer periphery of the first drive shaft 25 is formed.
This prevents the cylindrical member 29 from falling. A press spring 31 for attachment and detachment is interposed between the first drive shaft 25 and the cylindrical member 29, and a pressure spring 31 for attachment and detachment is provided on the inner periphery of the cylindrical member 29. An annular V-groove 32 is formed to allow movement of the pole 27 in the radial direction.

A sliding member 33 inserted into the rod 20 is slidably fitted inside the first drive shaft 25, and the sliding member 33 is prevented from falling at the stepped portion of the rod 20. . First drive shaft 25 and sliding member 3
A pressure spring 34 is provided between 3 and 3, and when the cylindrical member 29 is pushed up by hand in order to replace parts according to the size of the stud bolt 13, and when the second drive shaft (described later) is detached from the attachment/detachment ball 27. , sliding member 3
3 is lowered to prevent the detachable ball 27 from falling.

A second drive shaft 40 , which forms the main body of the socket 12 , is removably fitted into the inner periphery of the first drive shaft 25 , and a ball that engages with the attachment/detachment ball 27 is attached to the outer periphery of the second drive shaft 40 . A groove 41 is formed. A plurality of blind holes 42 are formed in the second drive shaft 40 in the radial direction below the ball groove 41, a locking ball 43 is held in each blind hole 42, and a pressing spring is provided between the blind hole 42 and the locking ball 43. 52 is interposed.

On the outer circumference of the second drive shaft 40, there are three
The equally divided gripping member 44 is slidably fitted, and the gripping member 44 is connected to the second drive shaft 40 so that the stud 13 can be gripped by the gripping portion 44a of the gripping member 44.
An elastic ring 45 is mounted which applies a force in the direction of contraction perpendicular to the axis of. The above-mentioned locking ball 43 is provided on the inner periphery of the upper part of the gripping member 44.
A V-shaped annular groove 46 is formed to engage with the gripping member 44, and when a predetermined upward force is applied to the gripping member 44 when inserting the stud 13 into the gripping portion 44a, the locking ball 43 moves inward. The gripping member 44 is adapted to rise. The lowering of the gripping member 44 is restricted by a pin 47 fixed to the second drive shaft 40.

A tapered hole (operating space) 48 is formed inside the lower end of the second drive shaft 40, and a stopper 49 is supported on the second drive shaft 40 coaxially with the second drive shaft 40 so as to be relatively rotatable and movable relative to each other. ing. A pin 5 is attached to the stopper 49 in a direction perpendicular to the axis of the stopper 49.
0 is fixed, and a communication hole 51 is formed below the pin 50 in the same direction as the pin 50.

A pair of half-split screw members 61 are fitted into the tapered hole 48 such that they can rotate relative to each other and move relative to each other in the axial direction, and a pin hole 60 through which the pin 50 is inserted is formed in the screw member 61. The threaded member 61 is expandable and contractable along the pin 50. A spring 62 that biases the threaded member 61 in the expansion direction is interposed between the threaded members 61 in the communication hole 51, and a stud bolt 1 is inserted inside the lower end of the threaded member 61.
A female thread 63 is formed to screw together the parts 3 and 3.

A holding hole 65 for holding the driving ball 64 is formed between the tapered holes 48 at the lower end of the second driving shaft 40, and the driving ball 64 is held on the outer periphery of the screwing member 61 as shown in FIGS. Engaging lead groove 6
6 is formed, and this lead groove 66 has a second lead groove 66 on the lower end side.
It is inclined in the radial direction away from the rotation center of the drive shaft 40 and in the opposite direction to the thumb screw 63. The lead groove 66 includes a parallel portion 66a parallel to the axis of the second drive shaft 40, and an inclined portion 66b continuous with the parallel portion 66a and having a larger inclination than the tapered hole 48. When the screwing member 61 is lowered relative to the second drive shaft 40, the drive ball 64 moves to the parallel portion 6.
6a, the screwing member 61 does not expand in the radial direction, and rotates relative to the second drive shaft 40 while descending, while between the inclined portions 66b, the screwing member 61 expands in the radial direction and rotates relative to the second drive shaft 40. It rotates relative to the drive shaft 40 while descending.

A series of operations for screwing the stud 13 into the workpiece W based on the above-described configuration will be described.

As shown in FIG. 4, the stud bolt 1 is temporarily tightened to the workpiece W with the threaded member 61 expanded in the radial direction at a lowered position with respect to the second drive shaft 40.
3 to the nut runner body 10 and the socket 12
lower. The stud 13 is attached to the gripping member 44
The upper end of the stud 13 comes into contact with the lower end of the stopper 49, and the threaded member 61 is inserted between the grip part 44a and the female thread 63 of the second
It rises relative to the drive shaft 40. As a result, the screwing member 61 rotates relative to the second drive shaft 40 while contracting in the radial direction against the spring 62 by the drive ball 64 and the lead groove 66, and the screwing member 61 is attached to the stud bolt 13. They mesh together all at once. Since the threaded member 61 rotates and engages with the stud bolt 13, the threads of the male thread of the stud bolt 13 and the female thread 6 of the threaded member 61 are connected to each other.
It is difficult to interfere with the mountain in number 3. When the drive ball 64 reaches the parallel portion 66a of the lead groove 66, the pair of threaded members 61 descend while rotating along the male thread of the stud 13, and rotate with the stud 13 and stopper 49 in contact with each other. The female threads 63 of the pair of threaded members 61 and the male threads of the stud bolt 13 are firmly engaged with each other without play in the direction. Even after the stud bolt 13 and the threaded member 61 engage and the socket 12 stops descending, the nut runner body 1
0 is lowered by the amount by which the stud 13 is screwed into the workpiece W while bending the pressure spring 24.

After the nut runner main body 10 stops descending, the rotating shaft 11 is rotated, but at this time, the stud 13 and the stopper 49 are already in contact with each other, so the rotation of the pair of threaded members 61 is smoothly transmitted to the stud 13. and the stud 13 is screwed into the mark W through the socket 12. When the stud bolt 13 is screwed in to a predetermined tightening torque, the rotating shaft 11 stops rotating. At this time, when the rotation of the stud bolt 13 is stopped, a force is applied to rotate the pair of threaded members 61 and the stopper 49, so that the stopper 49 and the stud bolt 13 bite, and the stud bolt Biting occurs between the male thread 13 and the female thread 63 of the screwing member 61.

Next, when the nut runner body 10 is raised, the socket 12 is raised leaving behind the threaded member 61 that engages with the stud 13. As the second drive shaft 40 rises relative to the threaded member 61, the threaded member 61 does not expand in the radial direction and the stud 13
As shown in FIG.
The biting between the male thread 3 and the female thread 63 of the screwing member 61 is released.

When the second drive shaft 40 further rises with respect to the threaded member 61, the drive ball 64 moves to the inclined portion 66b, and the pair of threaded members 61 have little movement in the radial direction while maintaining parallel postures. The socket 12 rotates while expanding, and the socket 12 is disengaged from the stud bolt 13 as shown in FIG.

<Effects of the Invention> As described above, in the present invention, a stopper is supported on the drive shaft so as to be movable in the vertical and rotational directions, and a pair of threaded members are connected to the stopper via pins so as to reduce and reduce the size in the radial direction. Since it has an expandable guided configuration, the pair of threaded members can be contracted and expanded in the radial direction while maintaining parallel positions, and can also be rotated and moved in the vertical direction relative to the drive shaft. be able to. Furthermore, the lead groove that engages with the ball held on the drive shaft is formed so that the lower end side is inclined in the direction away from the rotation center of the drive shaft and in the opposite direction to the direction of inclination of the thumb screw. When the drive shaft is lowered with the stopper in contact with the stopper, the pair of threaded members contract and descend while rotating along the male thread of the stud. As a result, even with a small movement in the radial direction of the pair of threaded members, when the stud is in contact with the stopper, the female threads of the pair of threaded members do not interfere with the threads of the male thread, and the stud bolt is attached to the female thread of the pair of threaded members. This has the effect of allowing the male threads to be tightly engaged. Conversely, when the drive shaft is raised with the female threads of the pair of male threads of the stud bolt engaged, the pair of threaded members expand due to the spring and extend along the male thread of the stud bolt. Since the pair of threaded members moves upward while rotating, the engagement between the female thread of the pair of threaded members and the male thread of the stud bolt can be released even with a small amount of movement in the radial direction of the pair of threaded members. You can obtain the effect of reliably canceling the .

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a partially sectional view of a nut runner for a stud bolt according to the present invention, and FIG. 2 is a partially cutaway view of the socket to show the outer periphery of the threaded member. Figures 3 and 4 are diagrams showing the operating state in which the socket is unscrewed from the stud bolt. 10... Nut runner body, 11... Rotating shaft,
13... Stud bolt, 21... Intermediate shaft, 25...
...First drive shaft, 40...Second drive shaft, 49...Stopper, 50...Pin, 61...Screwing member, 62
... Spring, 63 ... Female thread, 64 ... Drive ball, 66 ... Lead groove, W ... Work.

Claims (1)

[Claims] 1. A drive shaft is rotatably connected to the rotation shaft of the nut runner body that moves up and down relative to the stud bolt,
A pair of retractable and expandable threaded members are fitted into a tapered hole formed inside the lower end of the drive shaft in a shape that expands toward the stud bolt so that they can rotate relative to the drive shaft and move in the relative axial direction, A female thread is formed on the inner periphery of the lower end of the pair of screwing members to be screwed into the male thread of the stud bolt, and a spring is inserted between the pair of screwing members to bias the pair of screwing members in the expansion direction, A stopper that abuts the stud bolt is supported on the drive shaft so as to be relatively rotatable and movable in the axial direction, and a pin is provided on the stopper so as to protrude to both sides of the stopper in a direction perpendicular to the axial movement of the stopper. is slidably fitted into pin holes formed in the pair of screwing members to guide and support the pair of screwing members so that they can be contracted and expanded in the radial direction, and the ball is held at the lower end of the drive shaft. A nut runner for a stud bolt, characterized in that a lead groove that engages with the balls is formed on the outer periphery of the pair of screwing members along the tapered hole and inclined in a direction opposite to the female thread.