JP2013022710A - Bolt tensioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bolt tensioner capable of tightening and loosening a bolt and nut fastening the upper cover of a pressure vessel while capable of addressing another pressure vessel of a different size.SOLUTION: The bolt tensioner (1) comprises a nut fastening device (2) and first and second guide devices (4a, 4b) provided at both right and left sides thereof at a prescribed angle. The first and second guide devices (4a, 4b) are provided with guide plates (10a, 10b) capable of altering the mounting angle and guide rollers (13a, 13b) capable of changing the angle of axle. These tools allow the bolt tensioner to be addressed to another pressure vessel of a different size. Installment of a nut position detection sensor (18) and positioning adjustment devices (16a, 16b) allows the bolt tensioner (1) to determine its positioning.

Description

  The present invention relates to a bolt tensioner that tightens or loosens bolts and nuts that are tightening the top cover of a pressure vessel such as a heat exchanger, and is not limited to this. The present invention relates to a bolt tensioner suitable for application to relaxation.

  The construction of the nuclear power plant started in the middle of the 1960s in Japan, and the Tsuruga No. 1 reactor, Japan's first nuclear reactor, began commercial operation in 1970. More than 50 nuclear reactors have been built in the country, and multiple nuclear reactors of different sizes are operating at each power plant. For example, at the Mihama Nuclear Power Plant of Kansai Electric Power Co., Inc., it was necessary to construct a reactor with higher power generation capacity in response to the increasing power consumption year by year. A kW No. 1 reactor was built in 1972, a No. 2 reactor with 500,000 kW in 1972, and an No. 3 reactor with 82.6 million kW in 1976. Thus, in a general nuclear power plant, a plurality of reactors having different rated outputs are provided, and the sizes of the pressure vessels are also different. To ensure safe operation, the reactor is obliged to open the top of the pressure vessel and inspect the inside once a year. By the way, the pressure vessel is composed of a pressure vessel main body having an upper opening and a flange formed around the opening, and an upper lid for closing the opening. A plurality of stud bolts are embedded at equal intervals on the circumference of the flange portion of the pressure vessel main body, and a plurality of bolt holes are opened at positions corresponding to the stud bolts on the upper lid. Then, the upper lid is placed on the pressure vessel main body, the stud bolt is passed through each of the bolt holes, the nut is screwed into each of the stud bolts, and the upper lid is attached to the pressure vessel main body.

  A bolt tensioner is used for tightening such a nut. The bolt tensioner is provided with a puller that is fixed integrally with the head of the stud bolt, and the puller can be pushed up or pulled up with a predetermined force by hydraulic pressure or the like. Therefore, when the puller is fixed to the head of the stud bolt and the puller is pulled upward, the stud bolt is elastically deformed and extends. When the floating nut is rotated, the nut can be tightened with a desired tightening force. As a result, the upper lid of the pressure vessel can be uniformly tightened. When loosening the nut, similarly, the stud bolt is pulled upward by the puller to be elastically deformed, and the nut is rotated in the reverse direction. The nut can then be removed and the top lid can be opened.

JP-A-9-216133

  Different types of bolt tensioners have been proposed according to various literatures. For example, there is a bolt tensioner of a type not provided with a puller. Patent Document 1 describes a stud bolt fastening device, that is, a bolt tensioner, which is provided with a rod-shaped heating element instead of a puller. An axial hole for inserting a rod-shaped heating element is formed in a stud bolt which is a target of tightening by the stud bolt tightening device. When a rod-shaped heating body is inserted into the hole of the stud bolt and the stud bolt is heated, the stud bolt expands due to thermal expansion. As a result, the nut fastened to the stud bolt floats, so that the nut is rotated. When the stud bolt returns to room temperature, a desired tightening force can be obtained.

  Various types of bolt tensioners have been proposed in this way, but in the early 1970s, manual type bolt tensioners that manually perform positioning and operation of a hydraulic pump or the like were mainly used. However, fully automatic bolt tensioners that can be automatically operated by remote control have been developed in order to protect workers from radiation exposure and improve work efficiency. Such a bolt tensioner must be suspended by an electric hoist crane so that it can be moved to any stud bolt and automatically positioned. Therefore, a bolt tensioner having a predetermined guide device, for example, a bolt tensioner main body device, and a bolt tensioner including a pair of guide devices provided adjacent to both sides of the bolt tensioner main body is provided. In the bolt tensioner configured as described above, the bolt tensioner main body is suspended by the electric hoist crane and can be lifted above the pair of guide devices. Then, when the pressure vessel is slid horizontally on the circumference of the pressure vessel in this state, the pair of guide devices travels horizontally on the upper lid along the stud bolt. When the electric hoist crane is driven and the bolt tensioner body is lowered after reaching the predetermined position, the bolt tensioner body is aligned with a desired stud bolt. The arrangement of the bolt tensioner main body and the pair of guide devices will be described in more detail. These are arranged so as to be positioned at the vertices of the flat isosceles triangle. As already described, the stud bolts embedded in the pressure vessel are embedded at equal intervals on the circumference. That is, it is embedded on the circumference of a predetermined PCD, so-called a predetermined nut seat pitch diameter. Therefore, any one stud bolt and its left and right stud bolts are positioned at the apex of a flat isosceles triangle. The bolt tensioner is designed so that the shapes of these isosceles triangles are equal. Since the isosceles triangles have the same shape in this way, when the bolt tensioner body is suspended by the electric hoist crane and the bolt tensioner is slid laterally, the bolt tensioner is smoothly slid along the stud bolt, and the bolt tensioner The body will be aligned to the desired stud bolt. The bolt tensioner provided with such a pair of guide devices is designed according to the stud bolt PCD, and is prepared for each pressure vessel.

  A conventional bolt tensioner equipped with a pair of guide devices can also be automatically positioned to the desired stud bolt, so that the nut can be tightened remotely, and there is no risk of exposure to radiation. Is also expensive. However, there are some problems to be solved. Specifically, the bolt tensioner needs to be designed so that the arrangement of the bolt tensioner main body device and the pair of guide devices conforms to the PCD of the stud bolt, so the bolt tensioner must be designed for each pressure vessel. There's a problem. In general, a bolt tensioner has a complicated mechanism and is expensive, and requires a maintenance cost. Therefore, if a bolt tensioner is prepared for each pressure vessel, the cost increases.

  An object of the present invention is to provide a bolt tensioner that solves the above-described problems, and specifically, there is no need to prepare a bolt tensioner for each pressure vessel even in a pressure vessel having a different PCD. Accordingly, it is an object of the present invention to provide a bolt tensioner that can provide an apparatus at low cost and can automatically align and tighten a stud bolt accurately and efficiently.

  In order to achieve the above object, the present invention provides a pressure vessel main body in which a plurality of stud bolts are implanted at equal intervals along the circumferential direction in the opening, and a stud in the opening of the pressure vessel main body. A bolt tensioner for tightening or loosening a nut in a pressure vessel composed of an upper lid adapted to be tightened by a nut screwed into the bolt. The bolt tensioner includes a nut tightening device and first and second guide devices provided at left and right sides of the nut tightening device through a piston cylinder unit at a predetermined angle. The first and second guide devices each include a guide plate capable of adjusting the mounting angle in each guide device. The guide plate slides against the nut so that the bolt tensioner is guided when the bolt tensioner moves on the upper lid in the circumferential direction along the stud bolt. Each of the first and second guide devices is provided with a guide roller that can run on the upper lid and adjust the angle of the axle. Further, the first and second guide devices are provided with a positioning adjustment device comprising a rod that can be driven in the axial direction and a guide portion that is replaceably provided at the tip of the rod. A pair of rollers provided at the tip of the roller rolls in contact with the nut and the guide portion enters between two adjacent nuts so that the bolt tensioner is positioned.

  Thus, in order to achieve the above object, the invention according to claim 1 is a pressure vessel main body in which a plurality of stud bolts are implanted at equal intervals along the circumferential direction in the opening, and the pressure vessel main body. A bolt tensioner for tightening or loosening the nut in a pressure vessel comprising an upper lid adapted to be tightened to the opening of the stud bolt by a nut screwed into the stud bolt, wherein the bolt tensioner Consists of a nut tightening device and first and second guide devices provided at left and right sides of the nut tightening device at a predetermined angle, and the first and second guide devices are respectively guide devices. A guide plate adapted to adjust the mounting angle inside, the bolt tensioner on the top cover in the circumferential direction along the stud bolt When moving, the guide plate is sliding in contact with the nut, configured as a bolt tensioner characterized it by the bolt tensioner is guided.

According to a second aspect of the present invention, in the bolt tensioner according to the first aspect, the nut tightening device and the first and second guide devices are connected via a piston cylinder unit, respectively. When driven, the nut tightening device is configured to be lifted upward or lowered downward relative to the first and second guide devices.
According to a third aspect of the present invention, in the bolt tensioner according to the first or second aspect, one end of the guide plate is rotatable with respect to the housing of the first and second guide devices. It is pivotally attached, and the other end is connected via a predetermined cam mechanism, and is configured so that the mounting angle can be adjusted by driving the cam mechanism.
According to a fourth aspect of the present invention, in the bolt tensioner according to any one of the first to third aspects, each of the first and second guide devices includes a rod that can be driven in the axial direction, and the rod. A positioning adjustment device comprising a replaceable guide portion is provided at the tip of the guide, and when the rod is driven, a pair of rollers provided at the tip of the guide portion are brought into contact with the nut and roll to the guide. A portion enters between the two adjacent nuts, whereby the bolt tensioner is positioned.
According to a fifth aspect of the present invention, in the bolt tensioner according to any one of the first to fourth aspects, each of the first and second guide devices travels on the upper lid and includes an axle of the axle. A guide roller capable of adjusting the angle is provided.
According to a sixth aspect of the present invention, in the bolt tensioner according to any one of the first to fifth aspects, the first or second guide device includes a nut position detection sensor including a light projector and a light receiver. When the bolt tensioner travels on the upper lid, the light from the light projector is blocked by a nut or detected by the light receiver.
According to a seventh aspect of the present invention, in the bolt tensioner according to any one of the first to sixth aspects, the first or second guide device includes a linear gauge sensor that measures the height of the stud bolt. Configured to be provided.

  As described above, according to the present invention, the bolt tensioner includes the nut tightening device and the first and second guide devices provided on the left and right sides of the nut tightening device at a predetermined angle. The two guide devices each include a guide plate in which the mounting angle can be adjusted in each guide device, and when the bolt tensioner moves on the upper lid in the circumferential direction along the stud bolt, the guide plate is Since the bolt tensioner is guided by sliding against the nut, the bolt tensioner is lifted by the electric hoist crane to move the bolt tensioner laterally. It will not come off. Since the guide plate can be adjusted in its mounting angle, it is unique to the present invention that it is possible to easily cope with pressure vessels having different nut seat pitch diameters by changing the mounting angle. The effect is obtained.

  According to another invention, the nut tightening device and the first and second guide devices are respectively connected via the piston cylinder unit, and when the piston cylinder unit is driven, the nut tightening device is connected to the first and second guide devices. Thus, it is configured to be relatively lifted upward or lowered downward. Then, before moving the bolt tensioner in the lateral direction, only the nut tightening device is pulled up, and when the lateral movement is completed, the nut tightening device can be returned to the original position. The nut tightening device will not be disturbed. According to another invention, the guide plate is pivotally attached at one end to the housings of the first and second guide devices so that the other end is connected via a predetermined cam mechanism. Since the mounting angle can be adjusted by driving the cam mechanism, the mounting angle can be easily adjusted. According to another aspect of the invention, each of the first and second guide devices has a positioning adjustment device comprising a rod that can be driven in the axial direction, and a guide portion that is replaceably provided at the tip of the rod. When a rod is driven, a pair of rollers provided at the tip of the guide part rolls in contact with the nut and the guide part enters between two adjacent nuts so that the bolt tensioner is positioned. Therefore, the positioning can be performed accurately and accurately. According to another invention, each of the first and second guide devices is provided with a guide roller that travels on the upper lid and can adjust the angle of the axle, so that the travel is smooth. In addition, it is possible to cope with pressure vessels having different nut seat pitch diameters by adjusting the angle of the axle. According to still another invention, the first or second guide device is provided with a nut position detection sensor including a projector and a light receiver, and when the bolt tensioner travels on the upper lid, the light from the projector is transmitted by the nut. Since it is intercepted or detected by a light receiver, positioning accuracy is relatively rough, but positioning can be performed quickly. According to another invention, the first or second guide device is provided with the linear gauge sensor for measuring the height of the stud bolt, so that the extension amount of the stud bolt can be easily measured. It is possible to manage the tightening force of the upper lid of the pressure vessel.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows typically the bolt tensioner which concerns on embodiment of this invention, (a) (b) is the perspective view and top view of a bolt tensioner, respectively. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows typically the guide plate provided in the guide apparatus of the bolt tensioner which concerns on embodiment of this invention, The (a) is a perspective view of a guide plate, The (a) (c) is a guide plate It is a top view which shows a part. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows typically the guide roller provided in the guide apparatus of the bolt tensioner which concerns on embodiment of this invention, (a) is a perspective view, (i) (c) is a top view. It is a perspective view which shows a part of positioning adjustment apparatus provided in the guide apparatus of the bolt tensioner which concerns on embodiment of this invention. It is side surface sectional drawing which shows the nut fastening apparatus of the bolt tensioner which concerns on embodiment of this invention.

  A pressure vessel such as a nuclear reactor includes a pressure vessel main body and a dome-shaped upper lid C that seals an opening of the pressure vessel main body. A flange portion is formed in the opening of the pressure vessel body, and a plurality of stud bolts B, B,... Are implanted in the flange portion at equal intervals. On the other hand, the same number of bolt holes are formed in the flange portion F of the upper lid C in alignment with the stud bolts B, B,. The pressure vessel main body is covered with the upper lid C and tightened. At this time, the stud bolts B, B,... Of the pressure main body penetrate the bolt holes of the upper lid C and are nuts N, N,. The upper lid C is fixed to the pressure vessel main body by tightening with a predetermined tightening force. 1A shows a part of the upper lid C, stud bolts B, B,..., Nuts N, N,. A bolt tensioner 1 is shown. The bolt tensioner 1 according to the present embodiment travels on the upper cover C along the stud bolts B, B,..., And is aligned with any of the stud bolts B, B,. Or come to relax. In the figure, stud bolts B, B,... And nuts N, N,.

  A bolt tensioner 1 according to an embodiment of the present invention includes a nut tightening device 2 as a main body, and first and second guide devices 4a and 4b provided on the left and right sides of the nut tightening device 2. . As will be described in detail later, the nut tightening device 2 is elastically extended by pulling one stud bolt B upward by a puller provided therein, and is screwed onto the stud bolt B by a nut rotating mechanism. The mating nut N is tightened or loosened. The nut tightening device 2 is suspended by an electric hoist crane (not shown). The bolt tensioner 1 can be moved laterally along the circumferential direction of the upper lid C by the electric hoist crane.

  The first and second guide devices 4a and 4b have a substantially hollow box shape, and the bottom surface and both side surfaces are open. Then, approximately two stud bolts B and B and nuts N and N are inserted into the first and second guide devices 4a and 4b, respectively. Thus, since each of the first and second guide devices 4a and 4b is open on both sides, when the bolt tensioner 1 moves in the circumferential direction, the stud bolts B, B,. , It enters the device through the opening on one side and exits from the opening on the other side. That is, the inside of these devices 4a and 4b is a passage through which the stud bolts B, B,... And the nuts N, N,.

  The nut tightening device 2 and the first and second guide devices 4a and 4b are connected as follows. First, predetermined attachments 5a and 5b are provided on the left and right sides of the nut tightening device 2, and the first and second piston cylinder units 6a and 6b are respectively connected to the attachments 5a and 5b. It is fixed in the cylinder part. The first and second guide devices 4a and 4b are fixed to the tips of the piston rods 7a and 7b of the first and second piston cylinder units 6a and 6b. Since these piston rods 7a and 7b are driven in the vertical direction, when the first and second piston cylinder units 6a and 6b are driven and the nut tightening device 2 is lifted by the electric hoist crane, the first In the state where the two guide devices 4a and 4b are left on the flange portion F of the upper lid C, only the nut tightening device 2 can be pulled upward. The first and second guide devices 4a and 4b are connected to each other by two upper and lower guide device fixing bars 9 and 9 so that a predetermined angle is maintained. When the nut tightening device 2 and the first and second guide devices 4a and 4b are viewed from above, they are arranged so as to exhibit a flat isosceles triangle as shown in FIG. If such an arrangement is regarded as an arc, the diameter of the arc tube roughly matches the diameter of the circle connecting the centers of the stud bolts B, B,. To do. Accordingly, when the bolt tensioner 1 moves on the upper lid C in the circumferential direction, the bolt tensioner 1 is guided by the first and second guide devices 4 and 5.

  The first and second guide devices 4a and 4b are provided with a guide mechanism for accurately guiding the bolt tensioner 1, an alignment mechanism for aligning the bolt tensioner 1 with a desired stud bolt B, and the like. Yes. The guide mechanism includes guide plate mechanisms 11a and 11b including guide plates 10a and 10b, and guide roller mechanisms 14a and 14b including guide rollers 13a and 13b. The alignment mechanism includes positioning adjustment devices 16a and 16b. And a nut position detection sensor 18. These will be described.

  The guide plate mechanisms 11a and 11b are provided in the first and second guide devices 4a and 4b, respectively. However, since the guide plate mechanisms 11a and 11b are symmetrical to each other and are substantially the same shape, Only one guide plate mechanism 11a will be described.

  As shown in FIG. 1A, the guide plate mechanism 11a is fixed to the housing and the guide plate 10a whose mounting angle can be adjusted with respect to the housing of the first guide device 4a. It consists of a fixed guide plate 19a. The guide plate 10a is provided on the inner side near the center of the upper lid C, and the fixed guide plate 19a is provided on the outer side. Each of them has a plate shape with a predetermined length and a predetermined width, and when the bolt tensioner 1 moves in the circumferential direction on the upper lid C, these plates 10a, 10b, 19a, 19b are provided with nuts N, N,. It is designed to slide smoothly. FIG. 2A shows a state where the guide plate 10a is viewed from the arrow Y1 direction in FIG. The vicinity of one end of the guide plate 10 a is pivotally supported by a pin 22 on a bracket 21 formed in the casing of the first guide device 4 a, and is rotatable about the pin 22. The vicinity of the other end of the guide plate 10a is connected to the housing of the first guide device 4a via a predetermined cam mechanism. More specifically, the housing of the first guide device 4a is formed with upper and lower mounting portions 23, 23 extending horizontally. A hole is formed in the center of each of the attachment portions 23 and 23, and one coupling pin 24 is fitted in the vertical direction. A protrusion 25 is formed in the vicinity of the other end of the guide plate 10a. A vertical hole is formed in the protrusion 25, and a link pin 26 is inserted. The mounting portions 23 and 23 and the protrusion 25 of the guide plate 10a are connected by upper and lower links 27 and 27 having a predetermined shape. Specifically, the upper and lower links 27, 27 have a large-diameter hole at one end and a small-diameter hole at the other end. The small-diameter holes of the links 27 and 27 are pivotally supported by the projection 25 of the guide plate 10 a by the link pin 26. The large-diameter hole is pivotally supported by the coupling pin 24, and the coupling pin 24 is provided with eccentric shafts 28, 28, and is supported via the eccentric shafts 28, 28. A predetermined cam 30 is provided between the upper and lower links 27, 27 on the attachment portions 23, 23 side, and is pivotally supported by a coupling pin 24. The cam 30 is provided with a guide plate lever 31 that can be rotated by this lever. The protrusion 25 of the guide plate 10a is provided with a spacer 32 at the tip, and the cam 30 is in contact with the spacer 33 smoothly. Accordingly, when the cam 30 is rotated halfway by the guide plate lever 31, the spacer 30 is pushed by the cam 30 and the other end of the guide plate 10a is pushed forward. 2A and 2C show how the rotational position of the cam 30 changes according to the position of the guide plate lever 31 and the position of the guide plate 10a changes accordingly. If it does in this way, the attachment angle of the guide plate 10a with respect to the 1st guide apparatus 4a can be changed, and an attachment angle can be selected from two angles. Note that small holes 32, 32,... Are formed on the left and right sides of the mounting portions 23, 23, respectively, and a guide plate lock pin 34 is inserted into either of the left and right holes 32, 32. As a result, the guide plate lever 31 is locked and the cam 30 is locked.

  Next, the guide roller mechanisms 14a and 14b will be described. The guide roller mechanisms 14a and 14b are also provided in each of the first and second guide devices 4a and 4b. Since these are also symmetrical and substantially the same shape, only one guide roller mechanism 14a will be described. As shown in FIG. 3A, the guide roller mechanism 14a is provided with a guide roller 13a, so that the first guide device 4a can move smoothly in the lateral direction. . The guide roller mechanism 14a is provided in the first guide device 4a as follows. That is, the horizontal mounting plate 36 is fixed to the housing of the first guide device 4a. A guide roller adjusting plate 37 is provided so as to be in contact with the lower surface of the mounting plate 36 and is pivotally supported by the mounting plate 36 by a knock pin 38 so as to be rotatable. An axle support member 40 is fixed to the guide roller adjustment plate 37, and a guide roller 13a is provided on the axle support member 40 so as to be rotatable or rollable. A guide roller lever 41 is fixedly attached to the guide roller adjustment plate 37. When this lever is operated, the guide roller adjustment plate 37 can be rotated left and right with respect to the mounting plate 36, and the axle of the guide roller 13a can be rotated. The angle can be changed. The mounting plate 36 has two holes on the left and right, that is, mounting plate side holes 43 and 43, and the guide roller adjustment plate 37 also has two holes on the left and right, that is, adjustment plate side holes 44 and 44. It has been. When one mounting plate side hole 43 and one adjustment plate side hole 44 are aligned, the other mounting plate side hole 43 and adjustment plate side hole 44 are not aligned, and the other mounting plate side hole 43 and the other adjustment plate side hole 44 are not aligned. When the adjustment plate side hole 44 is aligned, the one attachment plate side hole 43 and the adjustment plate side hole 44 are not aligned. The angle of the axle of the guide roller 13a can be adjusted depending on which hole 43, 44 is aligned, and the angle of the axle can be selected from two angles. 3A and 3C, the mounting plate side holes 43 and 43 and the adjustment plate side holes 44 and 44 are aligned with each other when the one is aligned and the other is aligned. It shows how the angle changes. One guide roller lock pin 45 is inserted into the aligned mounting plate side hole 43 and adjustment plate side hole 44, and the guide roller adjustment plate 37 is locked to the mounting plate 36.

  Next, the positioning adjustment devices 16a and 16b will be described. Since these are also symmetrical and substantially the same shape, only one of them, specifically, the positioning adjustment device 16b provided in the second guide device 4b will be described. . As shown in FIG. 1, the positioning adjustment device 16 b includes a piston cylinder unit 47 and a guide portion 49, and the guide portion 49 can be attached to and detached from the tip of a rod 48 driven by the piston cylinder unit 47. Is provided. In such a piston cylinder unit 47, the cylinder is fixed to the housing of the second guide device 4b, and the rod 48 is driven in the horizontal direction toward the inside of the second guide device 4b. FIG. 4 shows a state in which the guide portion 49 is viewed from the tip direction. As shown in FIG. 4, the tip of the rod 48 is cut horizontally at the upper side and the lower side by a predetermined length, and a vertical hole 51 is opened at a portion left in the center. A guide portion 49 is connected to the vertical hole 51. The guide part 49 has a substantially square shape, the tip part is cut off in a tapered shape from the left and right, and the upper side and the lower side are cut out horizontally with a predetermined thickness. Accordingly, the tip portion has a shape in which the central portion protrudes forward with a predetermined thickness. In such a tip portion, two rollers 58 and 58 are rotatably provided at a stepped portion on the lower side. When the guide portion 49 is driven forward, the rollers 52 and 52 are brought into contact with two adjacent nuts N and N so that the guide portion 49 can smoothly enter between the nuts N and N. At this time, the bolt tensioner 1 is slightly shifted left and right, and the bolt tensioner 1 is accurately aligned. The guide portion 49 is hollowed out at the rear so that the rod 48 can be inserted. The hollowed portion is provided with a vertical columnar portion 50, which is formed to have an outer diameter that fits smoothly into the vertical hole 51 of the guide portion 49. In addition, a circular table 52 is formed on the upper surface of the guide portion 49, and a vertical hole is formed in the circular table 52 at a position shifted backward from the center of the circular table 52, and the cylindrical portion 50 also penetrates. ing. A predetermined shaft 53 is inserted into this hole, and a clamp 55 is fixed to the upper end portion of the shaft 53. A flat lock plate 56 is fixed to the lower end portion of the shaft 53, and the columnar portion 50 of the guide portion 49 is locked so as not to come out of the vertical hole 51 of the rod 48. When the clamp 55 is rotated on the circular table 52, the shaft 53 and the lock plate 56 are rotated. However, the lock plate 56 is aligned with the vertical hole 51 at a predetermined rotational position, and the lock is released. Can be removed. That is, the guide portion 49 can be removed from the rod 48.

  Next, the nut position detection sensor 18 will be described. In the present embodiment, the nut position detection sensor 18 is provided only in the first guide device 4a, and includes a light projector 59 and a light receiver 60 as shown in FIGS. Has been. The light emitted from the projector 59 is blocked by the nut N and received by the light receiver 60 at a position between the two adjacent nuts N and N. Accordingly, when the bolt tensioner 1 is slid in the circumferential direction, a rough position can be obtained by counting the number of times of light shielding, and a position where light can be received by the light receiver 60 is selected and stopped. The bolt tensioner 1 can be positioned with a certain degree of accuracy.

  In the present embodiment, the second guide device 4b is provided with a digital linear gauge sensor 62 as shown in FIG. When the rod 63 provided on the digital linear gauge sensor 62 is driven downward and brought into contact with the head of the stud bolt B, the height of the stud bolt B, that is, the amount of elongation can be accurately measured.

  The main body of the bolt tensioner 1, that is, the nut tightening device 2 will be described. As shown in FIG. 5, the stud bolt B has a plurality of horizontal grooves M, M,... Formed on the head thereof, and the nut N has vertical grooves T, T,. ... are formed at equal intervals. The nut tightening device 2 is engaged with such grooves M, M,..., The stud bolt B is pulled upward, elastically deformed and extended, and the nut N is rotated to tighten or loosen the nut N. It has become. The nut tightening device 2 according to the present embodiment includes a cylindrical casing 71, a stud bolt pulling mechanism 72 that pulls the stud bolt B upward, and a nut rotating mechanism 73 that rotates the nut N. Yes. The casing 71 is formed thick so that it can withstand a large load, and the casing 71 is formed thicker at the bottom 74. The casing 71 is placed on the flange portion F of the upper lid C of the pressure vessel at the bottom 74.

  The stud bolt pulling mechanism 72 includes a cylindrical puller 76 having a diameter substantially equal to that of the stud bolt B, and four split puller sockets 77, 77,..., 4 that are locked to each other and connect the puller 76 and the stud bolt B. .., A locking ring 78 that locks the split puller sockets 77, 77,... A socket opening / closing piston cylinder unit 79 that drives the locking ring 78, and a bolt pulling piston cylinder unit 81 that lifts the puller 76 together with the stud bolt B Etc. A plurality of horizontal grooves 82, 82,... Are formed in the lower portion of the puller 76. In each of the grooves 82, 82,..., The upper surface is horizontal, and the lower surface is reduced in taper shape. Since the grooves 82, 82,... Are engaged with the grooves formed in the four split puller sockets 77, 77,. The combined state is maintained, and the pulling force is efficiently transmitted to the four split puller sockets 77, 77,. The grooves M, M,... Formed in the stud bolt B are oriented in the opposite direction to the grooves 82, 82,... Of the puller 76, that is, the upper surface is tapered and the lower side is tapered. The surface is level. Therefore, when the grooves M, M,... Engage with the grooves formed in the four split puller sockets 77, 77,. The combined state is maintained, and the tensile force is efficiently transmitted to the stud bolt B. A through hole 83 is opened in the puller 76 in the axial direction, and a guide bar 85 for detecting the position of the stud bolt B is inserted into the through hole 83. A holding nut 86 is fixed to the upper portion of the puller 76.

  The four split puller sockets 77, 77,... Have a shape in which one cylinder is divided into four in the axial direction, are arranged so as to surround the stud bolt B and the puller 76, and are locked to each other. It is designed to have a single cylindrical shape. In FIG. 5, with respect to the center line CL indicated by the alternate long and short dash line, the unlocked state is shown on the left half, and the locked state is shown on the right half. A plurality of bolt engaging grooves 88, 88,... That engage with the grooves M, M,... Of the stud bolt B are formed on the inner peripheral surface of the split puller sockets 77, 77,. A plurality of puller engaging grooves 89, 89,... That engage with the grooves 82, 82,. Therefore, when the four split puller sockets 77, 77,... Are locked, the stud bolt B, the split puller sockets 77, 77,. On the outer peripheral surface of the split puller sockets 77, 77, ..., horizontal grooves 91, 91, ... are formed at equal intervals. These grooves 91, 91,... Are relatively wide, and the tapered surfaces 92, 92,.

  The locking ring 78 has a cylindrical shape and is provided so as to surround the four split puller sockets 77, 77,. On the inner peripheral surface of the locking ring 78, grooves 93, 93, ... having the same shape as the grooves 91, 91, ... formed on the outer peripheral surfaces of the split puller sockets 77, 77, ... are formed. Such a locking ring 78 is connected to a socket opening / closing piston / cylinder unit 79 via connecting members 94, 94 and can be driven in the axial direction. When the locking ring 78 is set to a predetermined position, the split puller sockets 77, 77,... Are unlocked and opened as shown on the left side of the center line CL in FIG. The outer peripheral surfaces of 77, 77,... Are in close contact with the inner peripheral surface of the locking ring 78. When the locking ring 78 is driven, the four split puller sockets 77, 77,... Are locked as shown on the right side of the center line CL.

  The cylinder 95 of the bolt pulling piston cylinder unit 81 is fixed to the casing 71, and a spherical washer 97 is fixed to the upper part of the piston 96. A holding nut 86 is placed on the spherical washer 97. Therefore, when the piston cylinder unit 81 for pulling the bolt is driven, the puller 76 can be pulled upward via the holding nut 86, whereby the stud bolt B can also be pulled upward.

  The nut rotation mechanism 73 includes a drive mechanism 98 having a gear and a nut rotation gear 99 that meshes with the gear and rotates. The nut rotating gear 99 is hollowed in the center so as to pass through the stud bolt B, and is arranged on the nut N. The nut rotation gear 99 is provided with nut sockets 101, 101,... That engage with the longitudinal grooves T, T,. Accordingly, when the drive mechanism 98 is driven, the nut rotation gear 99 rotates and the nut N rotates.

  The operation of the bolt tensioner 1 according to the present embodiment will be described. As shown in FIG. 1A, the bolt tensioner 1 is placed on the flange portion F of the upper lid C of the pressure vessel, and the nut tightening device 2 is placed at the position of the nut N of the predetermined stud bolt B. Has been placed. First, a method of measuring the amount of elongation for all stud bolts B, B,. The electric hoist crane lifts the nut tightening device 2 upward in response to a command from a controller (not shown). At this time, the first and second piston cylinder units 6a and 6b are driven so that only the nut tightening device 2 is lifted. Lifting is stopped in a state where the nut tightening device 2 is detached from the stud bolt B. The electric hoist crane moves the bolt tensioner 1 in the circumferential direction along the flange portion F of the upper lid C. At this time, the stud bolts B, B, ... pass through the inside of the first and second guide devices 4a, 4b, and the nuts N, N, ... are in contact with the guide plates 10a, 10b and the fixed guide plates 19a, 19b. Glide smoothly. Further, the first and second guide devices 4a and 4b smoothly run on the upper lid C by the guide rollers 13a and 13b. By these, the bolt tensioner 1 is guided and can move in the circumferential direction. The number of nuts N, N,... Passing through the inside of the first guide device 4a is counted by a nut position detection sensor 18 comprising a projector 59 and a light receiver 60. When the preset number is counted and it is confirmed that the nut tightening device 2 has reached the position of the stud bolt B to be measured for elongation, the movement of the bolt tensioner 1 in the circumferential direction is stopped. The positioning adjustment devices 16a and 16b are driven. Then, the guide portions 49, 49 enter between two adjacent nuts N, N,..., And the bolt tensioner 1 is slightly shifted left and right by the reaction. That is, the position is finely adjusted, and the bolt tensioner 1 is accurately positioned. The nut tightening device 2 and the stud bolt B have the same axis. The nut hoisting device 2 is lowered by driving the electric hoist crane. The nut N and the stud bolt B enter the nut tightening device 2. The extension amount of the stud bolt B in the second guide device 4b is measured by the digital linear gauge sensor 62 of the second guide device 4b. The amount of elongation is stored in the controller. Similarly, the nut tightening device 2 is lifted by the electric hoist crane, moved to the position of the stud bolt B to be measured for the next elongation amount, the elongation amount of the stud bolt B is measured, and stored in the controller. In this way, the extension amount is measured and stored for all the stud bolts B.

  Next, a method for tightening the nuts N, N,. In the controller, the order of tightening the nuts N, N,... Is set, and the bolt tensioner 1 moves in accordance with this order, and the nuts N, N,. In the same manner as the procedure for measuring the extension amount of the stud bolt B, the nut tightening device 2 is lifted by the electric hoist crane, and the nuts N, N,... Move. When the positioning adjusting devices 16a and 16b are driven and positioned and the nut tightening device 2 is lowered by the electric hoist crane, the stud bolt B and the nut N to be tightened enter the nut tightening device 2. In the nut tightening device 2, the locking ring 78 is driven by the socket opening / closing piston cylinder unit 79 to lock the split puller sockets 77, 77,. Then, the puller 76, the split puller sockets 77, 77,... And the stud bolt B are connected. The bolt pulling piston cylinder unit 81 is driven. Then, the stud bolt B connected to the puller 76 is pulled upward, elastically deformed, and stretched. The nut rotation mechanism 73 is driven to rotate the nut N. Tightening of the nut N is completed. In the same manner, the bolt tensioner 1 moves to the next nut N to be tightened and performs tightening. Tighten all nuts N, N,.

  When the nuts N, N,... Are tightened, the amount of elongation is measured for all stud bolts B, B,. .. Are measured by the same procedure as the first method for measuring the amount of elongation of the stud bolts B, B,... And stored in the controller. Compared to the amount of extension of the stud bolts B, B,... Measured before the nuts N, N,... Are tightened, that is, whether a desired tightening force is obtained. Confirm. Further, it is confirmed whether the elongation amount is uniform for all the stud bolts B, B,..., That is, whether the tightening force is uniform. In this way, the tightening force is managed.

  The method for loosening the nuts N, N,... Can be easily understood by those skilled in the art from the method for tightening the nuts N, N,. When the nuts N, N,... Are loosened, the amount of elongation of the stud bolts B, B,... May be measured before and after that and stored in the controller, or the nuts N, N,. When removing it, the measurement of the amount of elongation may be omitted.

  In the bolt tensioner 1 according to the present embodiment, when the guide plate mechanisms 11a and 11b and the guide roller mechanisms 14a and 14b are adjusted and the guide portions 49 and 49 of the positioning adjustment devices 16a and 16b are replaced, the nut seat pitch diameters are different. Two types of pressure vessels can be used. Specifically: The bolt tensioner 1 is lifted by an electric hoist crane and placed on a predetermined work table. The following adjustment is made on this work table. The guide plate mechanisms 11a and 11b are operated as follows. First, the guide plate lock pin 34 is removed from one of the holes 32 and 32 to release the lock. Next, as shown in FIGS. 2A and 2C, the guide plate lever 31 is operated to rotate the cam 30 halfway. Then, the mounting angle of the guide plates 10a and 10b changes. The guide plate lock pin 34 is inserted into the other holes 32 and 32 to lock the guide plate lever 31. The guide roller mechanisms 14a and 14b are operated as follows. First, the guide roller lock pin 45 is removed from the one mounting plate side hole 43 and the adjustment plate side hole 44 to release the lock. The guide roller lever 41 is operated to change the axle angles of the guide rollers 13a and 13b, as shown in FIGS. The guide roller lock pin 45 is inserted into the other mounting plate side hole 43 and the adjustment plate side hole 44 and locked. The positioning adjustment devices 16a and 16b are operated as follows. First, the piston cylinder unit 47 is driven to project the rod 48 forward. The clamp 55 is rotated at the guide portion 49 to release the engagement of the lock plate 56. The guide part 49 is removed by pulling out the cylindrical part 50 and the lock plate 56 of the guide part 49 from the vertical hole 51 of the rod 48. This guide part 49 is replaced with another guide part. The other guide parts are not shown in the figure. The cylindrical part of the other guide part is inserted into the vertical hole 51 of the rod 48. The clamp is rotated to rotate the lock plate, and the other guide portion is fixed to the rod 48. By these operations, the bolt tensioner 1 is adapted to pressure vessels having different nut seat pitch diameters.

  The embodiment of the present invention can be variously modified. For example, the nut tightening device 2 may be composed of other conventionally known nut tightening devices, and is not limited to this embodiment. For example, when a male screw is formed on the head of the stud bolt, it is possible to employ a puller in which a female screw that is screwed onto the male screw is formed. Then, it is possible to directly connect the puller to the stud bolt without providing a special split puller socket. Further, the coupling method of the nut tightening device 2 and the first and second guide devices 4a and 4b can be modified. In the present embodiment, these are described as being connected by the first and second piston cylinder units 6a and 6b, but a cylindrical casing in which the nut tightening device 2 is stored is provided separately. The casing and the first and second guide devices 4a and 4b may be coupled by a predetermined fixing member, and the nut tightening device 2 may be slidable in the vertical direction within the casing. The guide plates 10a and 10b can be modified. In the present embodiment, it has been described that the guide plates 10a and 10b are provided on the inner side near the center of the upper lid, and the fixed guide plates 19a and 19b are provided on the outer side. However, these arrangements may be reversed. . Further, the fixed guide plates 19a and 19b have been described so that the mounting angle is unchanged, but the mounting angle may be adjustable. Further, the sensor can be modified. In the present embodiment, it has been described that the extension amount of the stud bolt is measured by the digital linear gauge sensor 62 provided in the second guide device 4b. However, the nut tightening device 2 is provided with a digital linear gauge sensor. Alternatively, a strain sensor may be provided on the puller, and the extension amount of the stud bolt to be tightened may be directly measured.

DESCRIPTION OF SYMBOLS 1 Bolt tensioner 2 Nut clamping device 4a, 4b 1st, 2nd guide apparatus 6a, 6b 1st, 2nd piston cylinder unit 10a, 10b Guide plate mechanism 11a, 11b Guide plate mechanism 13a, 13b Guide roller 14a, 14b Guide roller mechanism 16a, 16b Positioning adjustment device 18 Nut position detection sensor 19a Fixed guide plate 21 Bracket 22 Pin 23 Mounting portion 24 Connection pin 25 Projection 26 Link pin 27 Link 28 Eccentric shaft 30 Cam 31 Guide plate lever 34 Guide plate lock pin 36 Mounting plate 37 Guide roller adjustment plate 38 Knock pin 41 Guide roller lever 45 Guide roller lock pin 47 Piston cylinder unit 48 Rod 49 Guide portion 44 Clamp 56 Lock plate 48 Roller 59 Throw Vessel 60 light receiver 62 digital linear gauge sensor 63 the rod 71 casing 72 stud bolt tensioning mechanism 73 the nut rotating mechanism 76 puller bar 77 Split play bar socket 78 locking ring 85 guide bar 86 holding the nut 98 drive mechanism 99 nut rotating gear

Claims (7)

A pressure vessel body in which a plurality of stud bolts are implanted at equal intervals along the circumferential direction in the opening, and a nut screwed into the stud bolt is tightened in the opening of the pressure vessel body A bolt tensioner for tightening or loosening the nut in a pressure vessel comprising an upper lid configured as described above,
The bolt tensioner comprises a nut tightening device and first and second guide devices provided at predetermined angles on the left and right sides of the nut tightening device,
The first and second guide devices each include a guide plate adapted to adjust the mounting angle in each guide device.
When the bolt tensioner moves on the upper lid in the circumferential direction along the stud bolt, the guide plate slides in contact with the nut, whereby the bolt tensioner is guided. 2. The bolt tensioner according to claim 1, wherein the nut tightening device and the first and second guide devices are connected via a piston cylinder unit, and when the piston cylinder unit is driven, the nut tightening device is A bolt tensioner, wherein the bolt tensioner is pulled upward or lowered downward relative to one or two guide devices. 3. The bolt tensioner according to claim 1, wherein one end of the guide plate is pivotally attached to the housing of the first and second guide devices, and the other end is A bolt tensioner which is connected via a predetermined cam mechanism and is capable of adjusting the mounting angle by driving the cam mechanism. The bolt tensioner according to any one of claims 1 to 3, wherein each of the first and second guide devices is provided with a rod that can be driven in an axial direction and a rod that can be exchanged at the tip of the rod. A positioning and adjustment device comprising a guide portion,
When the rod is driven, a pair of rollers provided at the tip of the guide portion rolls in contact with the nut and the guide portion enters between two adjacent nuts, thereby positioning the bolt tensioner. Bolt tensioner characterized by being adapted. The bolt tensioner according to any one of claims 1 to 4, wherein each of the first and second guide devices is provided with a guide roller that travels on the upper lid and can adjust an angle of the axle. Bolt tensioner characterized by The bolt tensioner according to any one of claims 1 to 5, wherein the first or second guide device is provided with a nut position detection sensor including a projector and a light receiver, and the bolt tensioner is connected to the upper lid. A bolt tensioner characterized in that when traveling on the light, the light from the light projector is blocked by a nut or detected by the light receiver. The bolt tensioner according to any one of claims 1 to 6, wherein the first or second guide device is provided with a linear gauge sensor for measuring a height of a stud bolt. Bolt tensioner.

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