JPH059214B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a nut attachment/detachment conveyance device, and in particular, to a nut attachment/detachment/conveyance device for attaching/detaching a nut to/from a stud bolt for fixing the top cover of a nuclear reactor pressure vessel or the like. Regarding equipment.

"Prior Art" Generally, a reactor pressure vessel in a boiling water nuclear reactor has a configuration shown in FIGS. 10 and 11. The reactor pressure vessel A has a structure in which the upper part of the vessel body B is covered with an upper cover C, and a large number (for example, 92 stud bolts) of stud bolts E are installed on the flange D of the vessel body B and are connected to the flange F of the upper cover C. It is designed to be passed through and fastened with a nut G. Code H
indicates a washer.

In addition, during nuclear fuel exchange and periodic inspections after the start of reactor operation, various works are carried out with the above-mentioned upper cover C removed, but since the work is within the radioactivity control area, it can be carried out efficiently with less labor. There is a need to do so.

Therefore, the present applicant has developed such a device for opening and closing the top cover, for example, ``Nut attachment/detaching work equipment'' in Japanese Patent Publication No. 59-11433, and ``Opening/Closing of Reactor Pressure Vessel Top Cover'' in Japanese Patent Publication No. 141478/1981. equipment” etc.,
A swivel table (frame) is mounted on the top cover, and a bolt/nut attachment/detachment unit such as a stud tensioner for loosening a nut or a nut attachment/detachment device is suspended from the swivel table so that it can run along the pitch circle of the stud bolt E. By automating the work of attaching and detaching the nut G from the stud bolt E using a stud tensioner, etc., we have achieved a reduction in the radiation exposure of workers.

``Problems to be Solved by the Invention'' By the way, the nuts removed from the stud bolts are transferred and stored on a work scaffold set up around the flange of the top lid until the top lid is re-fixed to the container body. However, in order to screw the work scaffold onto the stud bolt, it is necessary to accurately position the stud bolt with respect to the stud bolt, and it is also required to perform the screwing operation quickly and reliably.

The present invention effectively solves the above problems,
To provide a nut attachment/detachment device that handles nuts rationally, improves positioning accuracy with stud bolts, and quickly and reliably performs screwing operations.

"Means for Solving the Problems" The present invention has a nut attaching/detaching mechanism that is connected with an elevating mechanism and a forward/backward moving mechanism, and the nut attaching/detaching mechanism has a centering part placed on the head of a stud bolt. A rotatable cylindrical wrench is disposed so as to surround the centering portion and is removably engaged with the nut, and is movable vertically relative to the cylindrical wrench. The nut is characterized in that a driving part for rotating around the center is connected in series, and a plurality of centering rollers are arranged in the centering part so as to form a circumscribed circle that is approximately the same as the inner diameter of the nut.

``Function'' The nut attachment/detachment and conveyance device of the present invention attaches and detaches the nut by rotating the cylindrical wrench while engaged with the nut, and also moves the nut to the stud bolt using the elevating mechanism and the forward/backward moving mechanism. It can be transported to a nearby target location. When attaching a nut to a stud bolt, the nut is lowered while passing through a centering roller positioned relative to the stud bolt by the centering portion, and the nut is screwed while being aligned with the stud bolt. It is something that can be combined.

“Example” Hereinafter, a first example will be described in which the nut attachment/detachment device of the present invention is applied to an upper lid opening/closing device of a reactor pressure vessel.
This will be explained based on FIGS. 9 to 9.

In the figure, the symbols A to H indicate the parts corresponding to the parts of the reactor pressure vessel explained in FIGS. 10 and 11, the symbol J indicates the pitch circle of the stud bolt E, and the symbol K indicates the reactor housing. Shows the container. 6 to 8, reference numeral 1 is a top lid opening/closing device, in this top lid opening/closing device 1, numeral 2 is a fixed sling, numeral 3 is a rotating table, numeral 4 is a work scaffold, numeral 5 is a centering device,
Reference numeral 6 is a unit elevating device, 7 is a unit stand, 8 is a stud tensioner, 9 is a bolt attachment/detachment cleaning device, 10 is a nut attachment/detachment device according to the present invention, and 11 is a positioning device.

First, the outline of the top lid opening/closing device 1 will be explained.

As shown in Figures 4 to 6, the overall structure is as follows:
Each leg 12 of the fixed sling 2 is attached to mounting pieces Ca installed at a plurality of locations on the outer surface of the upper lid C, and a horizontal ring frame 13 is provided on the fixed sling 2. The ring-shaped turning table 3, which is placed above the pitch circle J of the stud bolt E, is mounted on the frame 13 via a plurality of rollers 14, and is turned by a turning drive mechanism 15, which will be described later. It's getting old.

The work scaffold 4 is formed into a ring shape having an inner diameter slightly larger than the flange F of the upper lid C,
It is suspended from the periphery of the rotating table 3 by a suspension device 16 such as a chain block.
On the upper surface of this work scaffold 4, a plurality of nut receivers 17 are provided so as to correspond to each stud bolt E when the work scaffold 4 is arranged around the upper lid C.
is installed. The nut receiver 17 supports the nut G and washer H that have been removed from the stud bolt E, and is formed into a pin shape as a whole.
A tapered portion 17a is formed at the tip, and the outer diameter of the base end 17b is set to be slightly larger than the inner diameter of the nut G and smaller than the inner diameter of the washer H. That is, when the nut G and washer H are extrapolated to the nut receiver 17, the washer H is arranged so as to surround the base end 17b, and the nut G is placed on the upper end of the base end 17b. In this supported state, there is a space between the nut G and the washer H in which an ejector pin of a nut attachment/detachment mechanism 10, which will be described later, can be inserted.

The center portion of the fixed sling 2 protrudes upward from a hole 3a in the center of the rotating table 3, and the distance between the outer circumferential portion of the protruding portion 2a and the inner circumferential portion of the rotating table 3 is adjusted. The centering device 5 is provided. Note that the protrusion 2a
A center platform 18 is placed over the top lid opening/closing device 1, and a hanging piece 19 for suspending the entire top lid opening/closing device 1 is provided.

The centering device 5 is for horizontally moving the turning table 3 in the radial direction and arranging it concentrically with the pitch circle J. A plurality of telescoping arms 21 are provided in a radial manner, and a plurality of sensors 22 are installed on the rotary table 3.
The rotary table 3 is suspended at a position outside the pitch circle J, and each sensor 22 detects the distance to the stud bolt E, and based on the results, the rotary table 3 is horizontally moved by the telescopic arm 21. ing.

The swing drive mechanism 15 is combined with one of the telescoping arms 21, and is rotated by a drive motor 25 by engaging a pinion 23 attached to the telescoping arm 21 with a gear 24 integrated with the inner circumference of the swing table 3. It is configured to allow

The unit elevating device 6 includes a rotating table 3.
For example, four are arranged at intervals of 90 degrees in the circumferential direction of the pitch circle J, and each
It is composed of an electric servo motor 26, a deceleration mechanism 27, and three ball screw jacks 28, and the unit stand 7 is horizontally attached to the lower end of the lifting rod 28a of each ball screw jack 28 via a link 29. It is being Two pins 30 connecting both ends of the link 29 are disposed along directions perpendicular to each other, and with such a connection structure, the unit base 7 is It is suspended from the lifting rod 28a so that it can be horizontally moved slightly back and forth and left and right.

The unit stand 7 integrally mounts a bolt/nut attachment/detachment unit, that is, the stud tensioner 8, a bolt attachment/detachment cleaning device 9, a nut attachment/detachment conveyance device 10, a positioning device 11, etc., of which the stud tensioner 8 is arranged approximately at the center of the unit base 7, and other bolt attachment/detachment cleaning devices 9 and the like are arranged so as to have a relative positional relationship with respect to the stud tensioner 8, which will be described later.

The stud tensioner 8 has the function of screwing the plastic bar 35 onto the stud bolt E and rotating the nut G while applying tension to the stud bolt E, and is suspended from the unit base 7 by a hanging rod 36. held.

The bolt attachment/detachment cleaning device 9 has a structure in which a bolt attachment/detachment mechanism 38 and a bolt cleaning mechanism 39 are housed in parallel and integrally in a housing 37 fixed to the lower surface of the unit base 7. The bolt attaching/detaching mechanism 38 is, for example, a mechanism for suspending the stud bolt E, which is a mechanism for suspending the stud bolt E, by applying mutatis mutandis the technology of the "stud bolt attaching/detaching device" described in Japanese Utility Model Publication No. 58-17737, which was previously proposed by the present applicant. Stud bolt E has a mechanism for screwing in or loosening E, and the nut G and washer H have been removed.
The structure is such that the stud bolt E can be attached and detached while the stud bolt E is suspended and the load applied to the threaded portion due to the stud bolt E's own weight is reduced, and most of its main parts move up and down within the housing 37. I'm starting to feel like I'm being forced to do that. Further, the bolt cleaning mechanism 39 is arranged to be offset by one pitch of the stud bolt E with respect to the bolt attaching/detaching mechanism 38, and by placing the cylindrical brush 40 on the stud bolt E and rotating it, the bolt cleaning mechanism 39 cleans the stud bolt E. It is designed to clean the threaded part of the

The nut attachment/detachment conveyance device 10 includes a nut attachment/detachment mechanism 41 for attaching/detaching the nut G to/from the stud bolt E while rotating it and gripping the washer, an elevating mechanism 42 for moving the nut attachment/detachment mechanism 41 in the vertical direction, and a longitudinal direction. The nut G, which has been loosened by the stud tensioner 8, is removed from the stud bolt E together with the washer H, and the nut receiver of the work platform 4 is moved. 17.

The elevating mechanism 42 includes a vertical support frame 45 that is integrally fixed to the lower surface of the unit base 7, and a feed screw 46 extending in the vertical direction is housed in the vertical support frame 45.
The horizontal support frame 48 of the longitudinal movement mechanism 43 is connected to the vertical slide block 47. The back and forth movement mechanism 43 is
A front-rear slide block 49 is moved by a feed screw (not shown) housed in a horizontal support frame 48 and extends in the front-rear direction, and a nut attaching/detaching mechanism 41 is connected to the front-rear slide block 49.

The nut attaching/detaching mechanism 41 has the structure shown in FIGS. 1 to 4, and includes a nut loosening part 50 that rotates the nut G with respect to the stud bolt E;
A nut washer holding part 51 that holds the loosened nut G and washer H, and a centering part 5 that positions the nut G with respect to the axis _X1 of the stud bolt E.
It is composed of 2.

The nut loosening section 50 includes a support ring 55 that extends in the vertical direction and is connected to the front and rear slide block 49 of the front and rear moving mechanism 43, and a rotating shaft that is rotated by a drive section 56 such as a motor. 57 is provided and rotatably supported by a bearing 58, and at the lower end of the rotating shaft 57,
A cylindrical wrench 59 that is engaged with the nut G is inserted so as to be movable up and down, and is pressed downward by an elastic member 60. The cylindrical wrench 5
9 has an inner diameter larger than the outer diameter of the stud bolt E, and has a protrusion 59a at its lower end that engages with a plurality of locking grooves Ga formed radially in the head of the nut G. The protrusion 59
The nut G is removed from the stud bolt E by engaging the nut G and rotating it while raising it by the elevating mechanism 42 in synchronization with the loosening of the nut G.

On the other hand, the nut washer holding part 51 has a bracket 61 protruding from the outer side of the support ring 55, and the nut loosening part 50 is attached to the bracket 61.
A cylindrical case 62 surrounding the is freely suspended via a hanging rod 63, and a nut holder 64 and a washer holder 65 are disposed at the lower end of the case 62. There is. Nut retainer 64
In the illustrated example, the rods are composed of cylinders, and are fixed to the outer circumferential portion of the case 62 in a plurality of inwardly facing positions at mutually spaced intervals in the circumferential direction, and the protruding rods 66 penetrate through the wall of the case 62. Case 6
These protruding rods 66 are arranged so as to be on the same horizontal level, and the nut G is placed on top of the protruding rods 66. Further, the washer retainer 65 is provided with a ring-shaped clamp film 67 made of rubber or the like along the circumferential direction on the inner circumference of the case 62 at a position below the nut retainer 64.
A compressed air supply system 68 is connected to the space between the inner peripheral surface of the case 62 and the washer H by expanding the clamp membrane 67 inwardly of the case 62 with compressed air. It is designed to be gripped by pressing the outer periphery.

Moreover, the centering part 52 is provided with an elevator 7 such as a cylinder on the upper surface of an end plate 69 that closes the upper part of the case 62.
0 is attached, and a guide rod 71 that is moved up and down by the elevator 70 passes through the end plate 69 and inserts the cylindrical wrench 5 into the case 62.
A centering roller 72 is supported on the outer periphery of the guide rod 71, and a centering cap 73 that is placed over the head of the stud bolt E is connected to the tip of the guide rod 71. The centering roller 72 is attached to a bracket 74 which is rotatably fitted onto the guide rod 71.
Three centering rollers 72 are supported at 120° intervals in the circumferential direction with their support shafts 75 parallel to the tangential direction of the guide rod 71, and the circumscribed circle of these three centering rollers 72 is the same as the nut G.
It is set to be the same as the inner diameter of. The centering cap 73 has a tapered inner surface 73a.
By being placed over the tapered part Ea formed on the head of the stud bolt E,
Center of the circumscribed circle of the centering roller 72 X ₂
is aligned with the axis _X1 of the stud bolt E. The case 62 is provided with a hole 62a through which the connecting portion between the support ring 55 and the front and rear slide blocks 49 and the connecting portion between the rotating shaft 57 and the driving portion 56 are inserted.

These stud tensioner 8, bolt attachment/detachment cleaning device 9, and nut attachment/detachment conveyance device 10
are supported on the unit base 7 along the pitch circle J of the stud bolt E at intervals that are integral multiples of the pitch. In other words, the stud tensioner 8
In terms of spacing, the bolt attachment/detachment mechanism 38 of the bolt attachment/detachment cleaning device 9 is twice the pitch, and the nut attachment/detachment mechanism 41 of the nut attachment/detachment conveyance mechanism 10 is twice the pitch.
is doubled on the side opposite to the bolt attachment/detachment mechanism 38,
The vertical support frame 45 is disposed outwardly from the pitch circle J.

Further, as shown in FIGS. 6 and 9, the positioning device 11 includes a main positioning section 8 that is integrated with a vertical support frame 45 in the nut conveying device 10.
1, and a sub-positioning section 82 attached to the housing 37 of the bolt attachment/detachment cleaning device 9. These positioning parts 81 and 82 are connected to a cylindrical rod 8 connected to the vertical support frame 45.
3 or the housing 37 supports a plurality of rollers 84 made of hard rubber or the like,
By setting the inscribed circles of these rollers 84 to be the same as or slightly smaller than the outer diameter of the stud bolt E, and placing the rollers 84 over the stud bolt E,
The structure is such that the axial center of the stud bolt E is aligned with the center of the inscribed circle for positioning. The main positioning part 81 is spaced apart from the stud tensioner 8 along the pitch circle J of the stud bolt E by four times the pitch, and the sub positioning part 82 is spaced apart from the stud tensioner 8 by four times the pitch. It is arranged to be shifted by one pitch to the opposite side from the main positioning part 81, and both of these positioning parts 81, 82
By this, the stud tensioner 8 and the like installed on the unit base 7 are arranged in a state where they are aligned with the bolt pitch circle J of the stud bolt E.

Next, a case will be described in which the upper cover C is removed from the vessel body B of the reactor pressure vessel A using the upper cover opening/closing device 1 having such a configuration.

By suspending the hanging piece 19 of the top lid opening/closing device 1, the fixed sling 2, the turning table 3, the work scaffold 4, each work unit, etc. are transported as one, mounted on the top lid C, and attached to the mounting piece Ca. Fix the legs 12 of the fixation sling 2. Next, the working scaffold 4 is placed on the protruding step on the inner wall of the reactor containment vessel K, with the nut support 17 of the working scaffold 4 and the stud bolt E corresponding to each other,
While releasing the connection state with the suspension device 16,
While the position of the stud bolt E is detected by the sensor 22 of the centering device 5, the rotary table 3 is horizontally moved by the telescoping arm 21, and the rotary table 3 is placed along the pitch circle J of the stud bolt E. let Then, the rotation table 3 is driven by the rotation drive mechanism 15 to cause each unit base 7 to travel along the pitch circle J, and the stud tensioner 8 is placed above the intended stud bolt E.

Next, the internal mechanism surrounded by the stud tensioner 8, the nut attaching/detaching mechanism 41 of the nut attaching/detaching conveyance device 10, and the housing 37 of the bolt attaching/detaching/cleaning device 9 is raised upward, and the unit base 7 is lifted up by the unit lifting device 6. lower it and position the unit stand 7 by the positioning device 11,
The stud tensioner 8 and the bolt attachment/detachment cleaning device 9 are respectively arranged on the axis of the stud bolt E, and the stud tensioner 8 is engaged with the stud bolt E. After loosening the nut G using the stud tensioner 8, the unit base 7 is raised and rotated by one pitch, and the nut attaching/detaching mechanism 41 is placed above the stud bolt E with the nut G loosened. is placed, the unit stand 7 is lowered again, and after the above-described positioning, the nut attaching and detaching conveyance mechanism 10 is driven to perform the nut G removal work.

This nut removal work will be explained in detail with reference to FIGS. 5A to 5H. First, as shown in FIG. Cover the tapered part Ea of the bolt E. Next, the position of the centering cap 73 is fixed, and while releasing the fluid on the piston end side, the lifting mechanism 42 lowers the support ring 55, and the case 62 is attached to the nut G as shown in FIG. At the same time, the cylindrical wrench 59 of the nut loosening portion 50 is engaged with the locking groove Ga of the nut G. And the nut relaxation part 5
The cylindrical wrench 5
While rotating the nut G, the nut loosening part 50 is raised by the elevating mechanism 42 so as to be synchronized with the loosening of the nut G. At this time, as shown in Figure 5C,
As the nut G rises, a gap is secured between the nut G and the washer H into which the protruding rod 66 of the nut retainer 64 can be inserted. Next, compressed air is sent into the space of the washer holder 65 to expand the clamp membrane 67 radially inward, thereby holding the washer H. After the nut G is removed from the threaded portion of the stud bolt E as shown in FIG. 5C, the ejector rod 66 is inserted and the nut G is placed on it. Next, as shown in FIG. place it on top. Next, as shown in Figure 5 E,
The nut attaching/detaching mechanism 41 is lowered so as to cover the nut receiver 17. When the nut G and the washer H are placed on the nut receiver 17, the washer H is arranged around the base end of the nut receiver 17, and the nut G is placed on the upper end of the base end, and the nut G is placed between them. A gap is formed between the two. Next, the holding state by the nut holder 64 and the washer holder 65 is released, and the nut attaching/detaching mechanism 41 is raised as shown in FIG. Wait on J.

Then, the unit base 7 is rotated by the rotation table 3.
While moving the stud bolt E one pitch at a time, remove all the nuts G and washers H, and remove the stud bolt E, which will be the passage position of the nuclear fuel when replacing the nuclear fuel, and some of the stud bolts E, etc. that will be inspected. is pulled out from the flange D of the vessel body B by the bolt attachment/detachment cleaning mechanism, and then the work scaffold 4 is connected to the lifting device 16 and raised, thereby lifting it off the protruding step on the inner wall of the reactor containment vessel K. Then, the fixed sling 2 is suspended, and a crane or the like is connected to the hanging piece 19 of the fixed sling 2, and the rotating table 3, upper cover C, work scaffold 4, etc. are suspended together with the fixed sling 2. Then, they are transported to the operation floor and stored.

On the other hand, when attaching the top cover C to the vessel body B after nuclear fuel exchange or periodic inspection, etc., the top cover C on the operation floor is suspended together with the top cover opening/closing device 1, and the top cover C is placed over the vessel body B. , the stud bolt E is fastened using each bolt/nut attachment/detachment unit.

Next, to explain the installation work of the nut G at the time of tightening, as shown in FIG. At the same time, insert the protruding rod 66 of the nut retainer 64 into the gap between the washer H and the nut G, and then tighten the nut G and the washer H as shown in FIG.
After holding, the elevating mechanism 42 and the back-and-forth moving mechanism 43 are driven to place the nut attaching/detaching mechanism 41 directly above the stud bolt E corresponding to the held nut G, etc., as shown in FIG. 5D. Then, as shown in FIG. 5, after the centering cap 73 is placed over the tapered portion Ea of the stud bolt E,
The nut G is lowered while being screwed into the stud bolt E by the lifting mechanism 42 and the nut loosening part 50. At this time, the taper part of the stud bolt E
The center _X2 of the circumscribed circle of the centering roller 72 is aligned with the axis _X1 of the stud bolt E by the centering cap 73 placed on the centering roller 72, and the circumscribed circle is aligned with the threaded portion of the stud bolt E. Since it is set to the same outer diameter as the Nut G
is guided along the axis _X1 of the stud bolt E while contacting the centering roller 72, and is accurately screwed into the threaded portion of the stud bolt E. Then, in the middle of screwing the nut retainer 6
4, and tighten the nut G to the stud bolt E as shown in FIG. The work of attaching the nut G to the stud bolt E is completed. Thereafter, the stud tensioner 8 is used to firmly tighten the studs.

That is, in this nut attachment/detachment conveyance device 10, before screwing the nut G onto the stud bolt E, the nut G is attached to the centering roller 72 by the centering cap 73.
is aligned with the axis _X1 of the stud bolt E, and the nut G is guided along the axis _X1 by the centering roller 72, making it possible to perform the fastening work accurately and quickly. It is possible. Therefore, even if there are slight variations in the dimensions and placement accuracy of the nut receiver 17, the nut G can be attached and detached reliably. Since the case 62 is suspended from the support ring 55, it is free to move slightly in the left and right direction, and can follow the alignment of the nut G.

In the present invention, the nut may be directly held by the cylindrical wrench, for example, by configuring the cylindrical wrench with a magnet.

"Effects of the Invention" As explained above, the nut attachment/detachment conveyance device of the present invention can provide the following effects.

(i) By rotating the cylindrical wrench while engaged with the nut, the nut can be attached and detached, and the nut can be transported to a predetermined position near the stud bolt by the elevating mechanism and the forward/backward moving mechanism. can.

() When attaching a nut to a stud bolt, the nut can be automatically centered on the stud bolt by lowering the nut while passing through a centering roller that is positioned relative to the stud bolt by the alignment section. , no skill is required, and the screws can be screwed together smoothly and reliably.

() With the above, it is possible to automate the work of attaching and detaching nuts, and to make it easier to manage the removed nuts and prevent them from being mixed with stud bolts, thereby saving labor and shortening the working time.

[Brief explanation of the drawing]

1 to 9 show an embodiment in which the nut attachment/detachment device according to the present invention is applied to an upper lid opening/closing device of a reactor pressure vessel. Figure 2 is a cross-sectional view taken along the - line in Figure 1, Figure 3 is a cross-sectional view taken along the - line in Figure 1, Figure 4 is a cross-sectional view taken along the - line in Figure 1, and Figure 5 is a cross-sectional view taken along the - line in Figure 1. Figures A to 5H are longitudinal cross-sectional views showing the state of the nut attachment/detaching mechanism in each process of nut attachment/detachment work, and Figure 6 is an overall front view of the top cover opening/closing device.
Figure 7 is a plan view with half of it in cross section, Figure 8 is a front view with part of the bolt/nut attachment/detachment unit including the nut attachment/detachment conveyor device in cross section, Figure 9 is its cross sectional view, and Figure 10 is the atomic A partially omitted vertical cross-sectional view showing the structure of the reactor pressure vessel, Figure 11 is the chain line in Figure 10.
It is an enlarged view of the part indicated by XI. A... Reactor pressure vessel, B... Vessel body, C...
...Top lid, Ca...Mounting piece, D...Body flange,
E... Stud bolt, F... Top cover flange, G
...Natsuto, H...Washer, J...Pitsuchi Yen, K...
...Reactor containment vessel, 1... Top lid opening/closing device, 2...
Fixed sling, 3... Swivel table, 4... Working scaffold, 5... Centering device, 6... Unit lifting device, 7... Unit stand, 8... Stud tensioner, 9... Bolt attachment/detachment cleaning device, 10...Nut attachment/detachment conveyance device, 11...Positioning device, 15...
Rotating drive mechanism, 17... Nut receiver, 22... Sensor, 23... Telescopic arm, 28... Ball screw jack, 28a... Lifting rod, 29... Link, 30... Pin, 37... Housing, 38 …
...Bolt attachment/detaching mechanism, 39...Bolt cleaning mechanism, 4
1... Nut attachment/detaching mechanism, 42... Lifting/lowering mechanism, 43
...Back and forth movement mechanism, 45...Vertical support frame,
46... Feed screw, 47... Vertical slide block, 48... Horizontal support frame, 49... Front and rear slide block, 50... Nut loosening part, 51...
... Nut washer holding part, 52 ... Centering part, 55
... Support ring, 56 ... Drive section, 57 ... Rotating shaft, 58 ... Bearing, 59 ... Cylindrical wrench, 59a
...Protrusion, 61...Bracket, 62...Case, 63...Hanging rod, 64...Nut retainer, 65...Washer retainer, 66...Extrusion rod, 67...Clamp membrane, 68... Compressed air supply system, 69... end plate, 70... elevator, 71...
Guide rod, 72...Centering roller, 7
3...Centering cap, 73a...Tapered surface, 7
4... Bracket, 75... Support shaft, 81... Main positioning part, 82... Sub-positioning part, 83... Cylindrical rod, 84... Roller, X ₁ ... Axis center of stud bolt, X ₂ ... ...The center of the circumscribed circle of the centering roller.

Claims (1)

[Claims] 1. The nut attaching/detaching mechanism is provided with an elevating mechanism that moves the nut attaching/detaching mechanism along the vertical direction, and a back-and-forth moving mechanism that moves the nut attaching/detaching mechanism in the front-rear direction perpendicular to the up-down direction, The attachment/detachment mechanism includes a centering part that is placed over the head of the stud bolt, and a rotatable cylindrical wrench that is arranged to surround the centering part and is removably engaged with the nut, and is movable vertically. The cylindrical wrench is provided with a driving part that rotates the wrench around the axis of the stud bolt, and the centering part has a plurality of centering rings so as to have a circumscribed circle that is approximately the same as the inner diameter of the nut. A nut attachment/detachment conveyance device characterized by being provided with rollers.