JP2000263459A - Bolt tensioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bolt tensioner to be applicable for even a flange hardly securing a part, receiving a reaction force, at the periphery of a nut, perform simultaneous fastening and unfastening of a plurality of nuts, and execute a nut fastening and unfastening work in a short time. SOLUTION: A bolt tensioner 1 is applicable to mounting and demounting of a flange 100 having a plurality of bolt holes 103 arranged on a concentric circle and applying a tensile force on a bolt V when a nut N threadedly engaged with a bolt V is fastened and unfastened. The bolt tensioner comprises a plurality of tension members 2 coupled with the bolt V; a support member 3 to mount the tension members 2 on a concentric circle; a cylinder bore part 6 formed in the support member 3; and a piston 7 situated in the cylinder bore part 6, and formed such that the part, inside each bolt hole 103, of the upper surface of the flange 100 is operated as a reaction force receiving part, and separating the support member 3 from the flange 100.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to various pressure vessels,
Applied when mounting and removing flanges of pumps, etc.
The present invention relates to a bolt tensioner used to apply a tensile force to a bolt when tightening and loosening a nut screwed to a bolt for fixing a flange.

[0002]

2. Description of the Related Art Conventionally, techniques in such a field include:
One disclosed in Japanese Patent Application Laid-Open No. H8-257932 is known. The conventional bolt tensioner described in this publication uses bolts (stud bolts) for fixing flanges (vertical flanges) of various pressure vessels and pumps.
And a puller (tensile member) to be connected to the bolt. When tightening and loosening the nut screwed to the bolt using this bolt tensioner, the lower end of the puller and the upper end of the bolt are connected to each other.

[0003] A housing is arranged around the puller, and a lower end surface of the housing comes into contact with an upper surface of the flange around a nut screwed to the bolt. A piston that can be raised and lowered by applying hydraulic pressure is provided at the upper end of the housing. A holding nut is fixed to the upper end of the puller bar, and the lower surface of the holding nut is in contact with the upper surface of the piston. Thus, if the piston is hydraulically driven to be raised, the puller is also raised together with the piston, so that a tensile force is applied to the bolt connected to the puller.
Then, a wrench or the like is inserted through an opening provided in the lower part of the housing, and the nut is tightened and loosened.

[0004]

However, since only one bolt can be applied with a conventional bolt tensioner, a relatively long time is required to tighten and loosen the nut. However, the work efficiency was not good. When a conventional bolt tensioner is used, as described above, the lower end surface of the housing supporting the puller contacts the upper surface of the flange around the nut. Therefore, the reaction force generated when a tensile force is applied to the bolt is received by the flange upper surface (seat surface portion) around the bolt (nut) to be pulled. On the other hand, in recent years, in order to increase the rigidity of the flange, the one in which the area of the bearing surface around the bolt hole is minimized has been used. However, in the case of this type of flange, a portion for receiving a reaction force generated when a tensile force is applied to the bolt cannot be secured around the nut. For this reason, it is difficult to apply a conventional bolt tensioner to this kind of flange, and it is necessary to employ a so-called heating method using a bolt heater or the like to apply a tensile force to the bolt. However, the heating method requires a long time (several days) for the operation, and the efficiency of the nut tightening and loosening operation is reduced.

Therefore, the present invention can be applied to a flange in which it is difficult to secure a portion for receiving a reaction force generated when a tensile force is applied to a bolt around a nut, and to tighten a plurality of nuts. It is an object of the present invention to provide a bolt tensioner that can perform nut tightening and loosening work in a short time.

[0006]

According to a first aspect of the present invention, there is provided a bolt tensioner for mounting and removing a flange having a plurality of bolt holes arranged concentrically and penetrating the bolt hole. A bolt tensioner that applies a tensile force to a bolt when tightening and loosening a nut screwed into the bolt.A plurality of tension members that can be connected to the bolt and a plurality of tension members can be mounted concentrically. A support member, a cylinder bore provided for the support member, and a piston disposed in the cylinder bore to separate the support member from the flange.

According to this bolt tensioner, when a tensile force is applied to the bolt, a portion of the upper surface of the flange to be applied, which is inside each bolt hole, the head of the bolt, the nut, and the bolt and the nut. In both cases, the seat surface around the nut and the like can be used as the reaction force receiving portion of the piston.
Here, the “plurality of tension members attached concentrically” includes “a pair of tension members positioned so as to be point-symmetrical to each other”.

[0008] In this case, it is preferable that the piston behaves as a reaction force receiving portion on the upper surface of the flange, inside the bolt holes.

When a tensile force is applied to a bolt using this bolt tensioner, the tension member is coupled to the bolt to be tensioned and attached to a support member.
In this state, if the working fluid is supplied into the cylinder bore of the support member, the piston operates as a reaction force receiving portion on the upper surface of the flange, inside the bolt holes, and the support member is moved from the flange. You will be separated. Accordingly, the tension member attached to the support member is also separated from the flange together with the support member, so that a tensile force is applied to the bolt connected to the tension member.

As described above, in this bolt tensioner,
The reaction force generated when a tensile force is applied to the bolt is received by a portion of the upper surface of the flange inside the bolt holes. Therefore, the bolt tensioner can be applied to a flange which is difficult to secure a portion for receiving a reaction force generated when a tensile force is applied to the bolt around the nut. Further, for example, if a tension member is coupled to a plurality of bolts positioned so as to be point-symmetrical to each other, it becomes possible to apply a tensile force to the plurality of bolts at once. Therefore, if this bolt tensioner is used, a plurality of nuts can be simultaneously tightened and loosened, so that the nut tightening and loosening work can be performed in a short time.

It is preferable that the support member is formed in an annular shape. If such a configuration is adopted, for example,
The bolt tensioner can be applied even when a component such as a main shaft penetrates a central portion of the flange like a flange of a vertical shaft pump.

In this case, it is preferable that each of the cylinder bore and the piston is formed in an annular shape. Further, a plurality of pistons are provided, and the cylinder bore is disposed concentrically and each piston May be composed of a plurality of holes in which are disposed.

Further, it is preferable that a fixing plate fixed to the upper surface of the flange located inside the bolt holes and supporting the supporting member is further provided, and the piston can be brought into contact with the fixing plate.

In this case, the fixing plate is fixed to the upper surface of the flange inside each bolt hole. The support member with the piston inserted into the bore of the cylinder is supported by the fixing plate. In this state, if the working fluid is supplied into the cylinder bore of the support member, the piston comes into contact with the fixed plate, and the support member is separated from the fixed plate. Thus, in this bolt tensioner, the reaction force generated when a tensile force is applied to the bolt is generated by the upper surface of the flange located inside each bolt hole via the fixing plate fixed to the upper surface of the flange. Can be received. Further, during the bolt pulling operation, the support member is supported in a stable state with respect to the flange, and the upper surface of the flange is protected by the fixing plate.

Preferably, the fixing plate rotatably supports the supporting member. Thus, the tension member can be easily moved to the position of the bolt to be tensioned by rotating the support member.

The bolt tensioner according to the present invention is applicable to various flanges. In particular, the bolt tensioner has a substantially frustoconical outer shape, and has an upper surface portion and each bolt hole so as to be located below the upper surface portion. The present invention is suitable for a flange including a plurality of seat portions provided around the nut and in contact with the lower surface of the nut, and a shoulder portion located between the seat portions. Since such a flange has high rigidity, even if a large tensile force is applied to the bolt, the reaction force can be reliably received by the upper surface of the flange.

On the other hand, the piston may operate at least one of the head of the bolt and the nut as a reaction force receiving portion.

When a tensile force is applied to a bolt using such a bolt tensioner, each piston is inserted into each cylinder bore of the support member, and the head or nut of the bolt that passes through the bolt hole, or , Each piston directly or indirectly abuts both the bolt head and the nut. The tension member is coupled to a bolt to be tensioned and attached to the support member. In this state, if a working fluid is supplied into the cylinder bore of the support member, the head or nut of the bolt, or both the head and nut of the bolt becomes a part receiving a reaction force, and the support member is a flange. Will be separated from This allows
Since the tension member attached to the support member is also separated from the flange together with the support member, a tensile force is applied to the bolt connected to the tension member.

Thus, in this bolt tensioner,
The reaction force generated when a tensile force is applied to the bolt is received by a bolt or a nut for fixing the flange, or both the bolt and the nut. Therefore, the bolt tensioner can be applied to a flange which is difficult to secure a portion for receiving a reaction force generated when a tensile force is applied to the bolt around the nut. Also,
For example, if a tension member is coupled to a plurality of bolts positioned so as to be point-symmetrical to each other, it becomes possible to apply a tensile force to the plurality of bolts at once. Therefore,
If this bolt tensioner is used, a plurality of nuts can be tightened and loosened at the same time, and the nut tightening and loosening operation can be performed in a short time.

Further, the piston may operate as a reaction force receiving portion with a seat portion provided around the nut with respect to the flange. In this case, a plurality of bolt through holes for penetrating the head of the bolt are provided, and on the upper surface side, an upper concave portion in which a tension member can be inserted is formed around each bolt through hole, and on the lower surface side, A lower recess for accommodating each nut is formed around each bolt through hole, and a spacer capable of supporting the support member on the upper surface and allowing the lower surface to abut against a seat surface around each nut. Good to use.

In these cases, it is preferable that a plurality of pistons are provided, and the cylinder bore is formed of a plurality of holes provided concentrically and each piston is provided.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a bolt tensioner according to the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a sectional view showing a first embodiment of a bolt tensioner according to the present invention. The bolt tensioner 1 shown in FIG. 1 is applicable when mounting and removing a general flange having a plurality of bolt holes arranged on concentric circles, and recently, a shaft seal of a reactor coolant pump (not shown). Flange 10 being adopted for parts and the like
It is also applicable to 0. Here, first,
The flange 100 will be described with reference to FIGS.

As shown in FIGS. 2 and 3, the flange 100
Is formed, for example, by cutting a cylindrical member, and has a substantially frustoconical outer shape having a thickness. At the center of the flange 100, a hole 101 through which a main shaft S (see FIG. 1) of a reactor coolant pump or the like penetrates is formed. Further, the flange 100 has an upper surface portion 102 formed in an annular and flat shape, and a plurality of mounting holes 106 are formed in the upper surface portion 102. A plurality of (eight in the example shown in FIG. 2) bolt holes 103 are provided around the upper surface portion 102.
Are arranged, and each bolt hole 103 is provided with a flange 10.
They are aligned at predetermined intervals on concentric circles around the center axis of zero.

Around each bolt hole 103, a bolt hole 1
A flat seat surface portion 104 is provided which comes into contact with the lower surface of the nut N screwed to a bolt V (stud bolt) penetrating through the nut 03. Each seat surface portion 104 is formed by cutting out (digging down) a side portion of the flange 100, and is located below the upper surface portion 102, as shown in FIG. A shoulder 105 having a conical side surface is arranged between the seating surfaces 104. Further, a portion above the seat surface portion 104 and between the shoulder portions 105 is cut into a cylindrical shape.

As described above, the flange 100 in which the shoulder 105 is disposed between the seating surfaces 104 has extremely high rigidity. On the other hand, the area of the seat surface portion 104 that comes into contact with the lower surface of the nut N is designed to be substantially equal to the projected area of the nut N as shown in FIG. Therefore, the lower surface of the nut N and the seat 1
04 (in a state in which the nut N is screwed into the bolt V), the seat surface portion 1 located around the nut N
04 has a very small area.

For this reason, in the flange 100, the bolt V
The reaction force receiving portion required for applying a tensile force to the nut cannot be secured around the nut N. Therefore, the flange 100
However, it is practically impossible to apply a conventional bolt tensioner. Based on this, the bolt tensioner 1 according to the present invention can be applied to the flange 100 where it is difficult to secure a portion for receiving a reaction force generated when a tensile force is applied to the bolt V around the nut N. ,
It is designed so that a plurality of nuts N can be simultaneously tightened and loosened.

As shown in FIG. 1, the bolt tensioner 1 is provided with a tension member (a puller) for applying a tensile force to the bolt N when tightening and loosening the nut N screwed to the bolt V passing through the bolt hole 103. ) 2 in plural (four in this case,
(See FIG. 4). A female screw portion is formed at the lower end 2 a of each tension member 2, and the female screw portion and the male screw portion of the bolt V are screwed with each other to form each tension member 2.
And the bolt V. A male screw portion 2b is formed at the upper end of each tension member 2.

Each tension member 2 is attached to a support member 3. The support member 3 is formed in an annular shape from chromium molybdenum steel or the like, and has a hole 3a at the center for passing a main shaft S of a reactor coolant pump or the like. Also,
As shown in FIG. 4, the support member 3 has four through holes 3b arranged at 90 ° intervals on a concentric circle on the outer periphery, and the tension member 2 is inserted into each of the through holes 3b. Let me do.
Each tension member 2 is inserted into each through hole 3b so that the male screw portion 2b projects from the upper surface of the support member 3, and the holding nut 4 and the lock nut 5 are inserted into the male screw portion 2b.
(See FIG. 1). Thereby, the tension member 2 is attached to the support member 3 and is aligned on a concentric circle.

As shown in FIG. 4 and the like, an annular cylinder bore 6 is formed around the hole 3 a of the support member 3. An annular piston 7 made of molybdenum steel is provided. Thereby, with respect to the inside of the cylinder bore 6,
If a working fluid (working oil) is supplied from the fluid supply passage 8 (see FIG. 1), the piston can be slid up and down within the cylinder bore 6. As shown in FIG. 1, a return fluid supply passage 10 used when raising the lowered piston 7 is communicated with the cylinder bore 6.

Hard chrome plating is applied to the inner peripheral surface of the cylinder bore 6, and a copper alloy is applied to the surface of the sliding portion of the piston 7. Thereby, the piston 7
Slides smoothly in the cylinder bore 6. Also,
As shown in FIG. 5, a stepped portion 7a is formed near the inner peripheral side center portion of the piston 7. The step 7 a contacts the upper end of the annular stopper nut 9 mounted on the lower part of the support member 3. Thus, when a hydraulic device (not shown) is connected to the fluid supply path 8 and a predetermined amount of hydraulic oil is supplied to the cylinder bore 6, the step 7a of the piston 7 comes into contact with the stopper nut 9, Further movement of the piston 7 is restricted.

The above-mentioned support member 3 is supported by a fixing plate 11. As shown in FIG. 1, the fixing plate 11 is formed in an annular shape from chromium molybdenum steel similarly to the support member 3, and the fixing plate 11 is provided with a mounting bolt 107 for the flange 100 located inside the bolt hole 103. Top part 1
02. As shown in FIG. 5, the fixing plate 11 supports an annular bearing 12, and an extension 3 formed below the support member 3 by an inner peripheral surface of the bearing 12.
c is supported.

The spring 1 is provided on the upper surface of the bearing 12.
4 are arranged. The upper end of the spring 14 has a substantially U-shaped cross section and supports an annular spring cover 15. The flat upper surface of the spring cover 15 is attached to the support member 3. Abuts against the lower surface of the stopper nut 9. At this time, as shown in FIG. 5, a predetermined gap C1 is formed between the lower end of the spring cover 15 and the upper surface of the bearing 12. on the other hand,
When hydraulic oil is supplied into the cylinder bore 6, the piston 7
Descends and comes into contact with the upper surface of the fixed plate 11. When the piston 7 is completely raised, a predetermined gap C2 is formed between the lower end surface of the piston 7 and the upper surface of the fixed plate 11.

As described above, the support member 3 is rotatably supported by the bearing 12 provided on the fixed plate 11. Therefore, it becomes possible to rotate the support member 3 on the flange 100 and easily move the tension member 2 to the position of the bolt V to be tensioned. A predetermined gap C1 is formed between the lower end of the spring cover 15 and the upper surface of the bearing 12, and when the piston 7 is completely raised, the lower end of the piston 7 and the fixed plate 11 A predetermined gap C2 is formed between the upper surface and the upper surface. Therefore, the piston 7
And fixing plate 11, and spring cover 15 and bearing 12
Can be prevented from being pressure-bonded to the upper surface.

Next, a procedure for using the above-described bolt tensioner 1 will be described with reference to FIG. Here, a procedure for applying a tensile force to the bolt V for fixing the flange 100 provided on the shaft sealing portion of the reactor coolant pump (not shown) using the bolt tensioner 1 will be described.

In this case, first, as shown in FIG. 1, the mounting bolt 107 is screwed into the mounting hole 106 of the flange 100, and the fixing plate 11 is fixed to the flange 100. Thereby, the fixing plate 11 is fixed to the upper surface portion 102 of the flange 100 located inside each of the bolt holes 103,
The upper surface portion 102 of the flange 100 is covered and protected by the fixing plate 11. The bearing 1 is fixed in the fixing plate 11.
2. The spring 14 and the spring cover 15 are arranged. Further, the piston 7 is inserted into the cylinder bore 6, and the support member 3 with the stopper nut 9 attached is supported by the fixing plate 11.

Here, the support member 3, the cylinder bore 6,
Since the piston 7, the fixed plate 11, and the like are each formed in an annular shape, the hole 101 is formed with a component such as the main shaft S, such as a flange 100 applied to a vertical shaft reactor coolant pump or the like. , The bolt tensioner 1 can be applied. In addition, during the bolt pulling operation, the support member 3 is supported by the fixing plate 11 in a stable state with respect to the flange 100.

Further, in each through hole 3b of the support member 3,
The tension member 2 is inserted. Then, the holding nut 4 and the lock nut 5 are screwed into the male screw portion 2 b of the tension member 2, and the four tension members 2 are attached to the support member 3. Each tension member 2 is coupled (screwed) to a bolt V to be tensioned.

In this state, when hydraulic oil is supplied into the cylinder bore 6 of the support member 3, the piston 7
Abuts the top surface of the Then, the pressure of the hydraulic oil between the upper end of the piston 7 and the cylinder bore 6 increases, and the support member 3 rises with respect to the piston 7 and separates from the fixed plate 11. As a result, each of the tension members 2 attached to the support member 3 is also moved together with the support member 3 by the flange 100.
, A tensile force is applied to the bolt V connected to each tension member 2. Then, the nut N screwed to the bolt V is tightened with a wrench (not shown) in a state where hydraulic pressure is applied to the cylinder bore 6, that is, in a state where a tensile force is applied to the bolt V.

As described above, in the bolt tensioner 1, the upper surface 102 of the flange 100 located inside each bolt hole 103 is fixed to the bolt V via the fixing plate 11 positioned on the upper surface 102 of the flange 100. Will receive a reaction force generated when a tensile force is applied to the plate. That is, the piston 7 arranged in the cylinder bore 6 of the support member 3
The portion inside of 3 operates as a reaction force receiving portion, and separates support member 3 from flange 100. Accordingly, the bolt tensioner 1 can be applied to the flange 100 where it is difficult to secure a portion for receiving a reaction force generated when a tensile force is applied to the bolt V around the nut N.

Further, since the above-described flange 100 has high rigidity, even if a large tensile force is applied to the bolt V, the reaction force can be reliably received by the upper surface portion 102 of the flange 100. Therefore, if the tension member 2 is coupled to four bolts that are positioned so that two bolts are point-symmetric with each other, it is possible to apply a pulling force to each bolt V at a time. Therefore, if this bolt tensioner 1 is used, a plurality of nuts N can be tightened and loosened at the same time, and the work of tightening and loosening the nuts N can be performed in a short time.

Although the above-described bolt tensioner 1 is suitable to be applied to the above-described flange 100 having a substantially truncated cone shape, the bolt tensioner 1 is arranged concentrically by changing the shape of the fixing plate 11. It can also be applied when mounting and removing a general flange having a plurality of bolt holes. The number of the tension members 2 attached to the support member 3 is not limited to four, but may be two or three (120 ° intervals), and can be further increased if the rigidity of the flange is sufficient. It is.

FIG. 6 is a sectional view showing a modification of the above-described bolt tensioner 1. As shown in FIG. The bolt tensioner 1A shown in the figure is a fixing plate 11 of the bolt tensioner 1 shown in FIG.
And a fixing plate 11A different from the above. No bearing, spring, spring cover, and the like are arranged on the fixed plate 11A, and the lower surface of the stopper nut 9 is directly supported by the upper surface of the fixed plate 11A. Thereby, the configuration of the bolt tensioner 1A can be simplified. Also,
Since the fixing plate 11A does not rotatably support the supporting member 3, the supporting member 3 is provided on the upper surface of the supporting member 3.
(Eye bolt) 16 for lifting and rotating
Is provided. The number of the hanger 16 is preferably at least three in consideration of the balance when the support member 3 is raised and lowered. Note that, instead of providing the fixed plate having no rotation support mechanism, the stopper nut 9 and the fixed plate 11A may be integrated.

FIG. 7 is a sectional view showing another modification of the bolt tensioner 1 described above. The bolt tensioner 1B shown in the figure has a plurality of small-diameter cylindrical pistons 7B. The cylinder bore 6B formed in the support member 3B of the bolt tensioner 1B is formed as a plurality of circular holes in which the pistons are arranged, and is arranged concentrically. In order to apply the bolt tensioner 1 when a component such as the main shaft S penetrates the hole 101 of the flange 100, such a configuration can be adopted. In this case, a plurality of holes may be provided concentrically with respect to the support member, and the fluid pressure cylinder may be fixed to each hole.

The supporting member 3B is provided with through holes 3b in a number corresponding to the number of bolts V (16 in this case) for fixing the flange 100. The tension member 2 can be inserted into each through hole 3b. When the bolt tensioner 1B is used, the tension members 2 are inserted into all the through holes 3b of the support member 3B disposed on the flange 100, and all the tension members 2 and the bolts V are connected. And a plurality (for example, 2
Only four tension members 2 connected to the bolts V are attached to the support member 3 using a holding nut and a lock nut, and the piston 7 is operated in this state. This makes it possible to efficiently apply a tensile force to the plurality of bolts V while suppressing the load applied to the flange 100.

FIG. 8 is a sectional view showing still another modification of the bolt tensioner 1 described above. As in the bolt tensioner 1B shown in FIG. 7, the same number of through holes 3b as the number of bolts V for fixing the flange 100 are formed in the support member 3C of the bolt tensioner 1C. In addition, as shown in the left part of FIG.
Abutting portion 3 that contacts the surface of shoulder 105 of flange 100
d is provided. That is, the contact portion 3d is provided to the support member 3C so as to correspond to the position of the shoulder portion 105 of the flange 100, and the inner peripheral surface thereof is
5 is formed in a conical surface shape. on the other hand,
As shown in the right part of FIG.
The contact portion 3d is not provided at the position corresponding to 04, so that the nut N can be easily tightened and loosened.

In the bolt tensioner 1C, a plurality (for example, 16) of cylinder bores 6C are formed concentrically near the upper surface of the support member 3C, and each of the cylinder bores 6C has a piston. 7C is provided. A through hole for holding the tension member 2 coaxially is provided in the center of the piston 7C, and each of the tension members 2 protruding from the upper surface of the piston 7C is held in contact with the upper surface of the piston 7C. A nut 4 can be mounted. That is, in this bolt tensioner, one piston 7 </ b> C is provided for one tension member 2.

The tension member 2 is coupled to, for example, a plurality of (for example, two to four) bolts V positioned so as to be point-symmetric with each other. Thus, if a working fluid (working oil) is supplied into the cylinder bore 6C, the tension member 2
And the tensile force can be applied to the bolt V. In this case, in order to secure an effective area of the piston 7C, it is preferable to set a large outer diameter at the upper portion of the support member 3C. When the bolt tensioner 1C is used, all the tension members 2 and the bolts V are connected in advance, and when the tension is actually applied to the bolts V, the bolts V are combined with the bolts V to be pulled. Tension member 2
, The holding nut 4 may be mounted. Thereby, the construction period of the bolt tension work can be shortened.

When a tensile force is applied to the bolt V using the bolt tensioner 1C, the reaction force is applied to the upper surface 1 of the flange 100 located inside each bolt hole 103.
As with 02, it is also received by the surface of the shoulder 105 of the flange 100. Further, since the reaction force is also received by the surface of the shoulder portion 105 of the flange 100, the line of action between the tension force applied to the bolt V by the piston 7C and the reaction force can be made closer.

The thus configured bolt tensioner 1
C can also be applied to the flange 100 where it is difficult to secure a portion around the nut N for receiving a reaction force generated when a tensile force is applied to the bolt V. Therefore, if this bolt tensioner 1C is used, a plurality of nuts N can be tightened and loosened at the same time, and the work of tightening and loosening the nuts N can be performed in a short time. In addition, in the bolt tensioner 1C shown in FIG.
The upper surface 102 of the flange 100 also receives the reaction force generated when a tensile force is applied to the bolt V, but receives the reaction force only at the shoulder 105 of the flange 100. You may do so. In addition, the surface of the shoulder 105 and the inner surface of the contact portion 3d may be formed in a step-like manner so that the support member 3C does not shift or slip from the flange 100.

FIGS. 9 and 10 show a second embodiment of the bolt tensioner according to the present invention. The bolt tensioner 20 shown in FIG. 1 is, for example, a flat annular flange 1 provided with a hole 101A for inserting a pipe P in the center.
This is applicable to tightening the nut N screwed to the bolt V. This flange 100A also has a plurality of bolt holes 103A arranged concentrically, and has a narrow seat surface portion 104A similarly to the flange 100 described above. Such a flange 100
For A, various pipes, valves, joints and the like are often joined, and it is difficult to use a conventional bolt tensioner.

As shown in FIG. 9, the bolt tensioner 20 has a support member 23 formed in an annular shape. At the center of the support member 23, a hole 23a having an inner diameter substantially equal to the outer diameter of the pipe P is formed. Further, in the outer peripheral portion of the support member 23, for example, through holes 23 b for allowing the tension member 22 to pass therethrough are formed at four positions separated by 90 °. The support member 2 is inserted through the through hole 23b.
A holding nut 24 is mounted on the tension member 22 protruding from the upper surface of the holder 3. Thereby, the tension member 22
Are attached to the support member 23 and are aligned on a concentric circle around the central axis of the support member 23.

Further, as shown in FIG.
In a portion of the outer peripheral portion where the through hole 23b is not provided, a circular cylinder inner cavity portion 26 is provided with a flange 100A.
Is formed so as to correspond to the position of the bolt hole 103A. A cylindrical piston 2 is provided in the cylinder bore 26.
7, and a working fluid (working oil) is supplied by a hydraulic device (not shown). Hole 23a of support member 23
When the tension member 22 and the bolt V are connected with each other by inserting the pipe P through the
It comes into contact with the head of the bolt V passing through the bolt hole 103A of 00A.

When a tensile force is applied to the bolt V using the bolt tensioner 20, if a working fluid is supplied into the cylinder bore 26 of the support member 23, the head of the bolt V becomes a portion receiving a reaction force. The support member 23 is
It will be separated from 0A. Thereby, the support member 2
3 is also separated from the flange 100A together with the support member 23, so that a tensile force is applied to the bolt V connected to the tension member 22.

As described above, in the bolt tensioner 20, the reaction force generated when a tensile force is applied to the bolt V is received by the bolt V for fixing the flange 100A. Therefore, this bolt tensioner 20 is
Can be applied to the flange 100A where it is difficult to secure a portion for receiving the reaction force generated when a tensile force is applied to the periphery of the nut N. In addition, if a tension member is connected to four bolts that are positioned so that two bolts are symmetrical to each other, it is possible to apply a pulling force to a plurality of bolts V at a time. Therefore, if this bolt tensioner 20 is used, a plurality of nuts N can be tightened and loosened at the same time, and the work of tightening and loosening the nuts N can be performed in a short time.

The bolt tensioner 20 can also be applied to the above-described flange 100 having a substantially truncated conical shape by using a long tension member 22. Further, the number of the tension members 22 is not limited to four, but may be two or three, or may be further increased. In the example described above, the head of the bolt V is used as the reaction force receiving portion of each piston 27, but the present invention is not limited to this. That is, a concave portion may be provided at an end of each piston, and each piston 27 may be used as a reaction force receiving portion using the upper surface of the nut N, or both the head of the bolt V and the upper surface of the nut N.

FIG. 11 is a sectional view showing a third embodiment of the bolt tensioner according to the present invention. The bolt tensioner 30 shown in the figure is applicable to an annular flange 100A where it is difficult to use a conventional bolt tensioner. In this bolt tensioner 30, the support member 33
A plurality (for example, 16) of cylinder bores 36 are formed concentrically near the upper surface of the cylinder 100 so as to correspond to the bolt holes 103 of the flange 100A. Below each cylinder bore 36, a through-hole 33b for inserting the tension member 32 is formed.

Each cylinder bore 36 has a piston 37
Is arranged. A tension member 32 is provided at the center of the piston 37.
Are provided coaxially. A holding nut 34 that is in contact with the upper surface of the piston 37 can be attached to each of the tension members 32 that are inserted through the piston 37 and protrude from the upper surface. That is,
In this bolt tensioner 30, one piston 37 is provided for one tension member 32. Further, FIG.
As shown in the figure, the lower surface 33c of the support member 33 is formed flat.

When a tensile force is applied to the bolt V using the bolt tensioner 30, a spacer S as shown in FIG. 11 is used. This spacer S has a plurality (the bolt holes 10 of the flange 100A) penetrating the head of the bolt V.
3A) (the same number as 3A). Spacer S
The upper concave side S2 into which the tension member 32 can be inserted
Are formed around each bolt through-hole S1, and a lower recess S3 for accommodating each nut N is formed around each bolt through-hole S1 on the lower surface side. It can be brought into contact with the seat surface 104A around the nut N. The upper surface of the spacer S is formed flat. Prior to using the bolt tensioner 30, the spacer S is first placed on the flange 100A.

After the spacer S is mounted on the flange 100A, the bolt tensioner 30 is mounted on the upper surface of the spacer S. Then, the tension member 32 is coupled to, for example, a plurality of (for example, two to four) bolts V positioned so as to be point-symmetrical to each other. In this state, the cylinder bore 3
If a working fluid (working oil) is supplied into the inside of the tension member 32,
And the tensile force can be applied to the bolt V. At this time, the piston is supported by the support member 33 and the spacer S.
, Each seat surface portion 104A provided on the flange 100A operates as a reaction force receiving portion.

As described above, according to the bolt tensioner 30, it is possible to simultaneously tighten and loosen the plurality of nuts N while effectively using the entirety of all the seating surfaces 104A provided on the flange 100A. In addition, the work of tightening and loosening the nut N can be performed in a short time. When using the bolt tensioner 30, all the tension members 32 are connected to the bolts V, and only the bolts V to be tensioned are held by the holding nuts 34.
May be attached. Further, the lower concave portion S3 of the spacer S may be formed so as to be in contact with any or all of the side surface and the upper surface of the nut N and the head of the bolt V. Thus, the head of the nut V, the bolt V, and the like can also be used as the reaction force receiving portion of the piston 37.

[0062]

Since the bolt tensioner according to the present invention is constructed as described above, a portion for receiving a reaction force generated when a tensile force is applied to the bolt is hardly secured around the nut. The present invention is also applicable, and it is possible to simultaneously tighten and loosen a plurality of nuts, so that the nut tightening and loosening operation can be performed in a short time.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a bolt tensioner according to the present invention.

FIG. 2 is a plan view showing an example of a flange to which a bolt tensioner according to the present invention can be applied.

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is a sectional view taken along line IV-IV in FIG. 1;

FIG. 5 is an enlarged sectional view of a main part of the bolt tensioner shown in FIG.

FIG. 6 is a sectional view showing a modification of the bolt tensioner shown in FIG.

FIG. 7 is a sectional view showing another modification of the bolt tensioner shown in FIG. 1;

FIG. 8 is a sectional view showing still another modification of the bolt tensioner shown in FIG.

FIG. 9 is a sectional view showing a second embodiment of the bolt tensioner according to the present invention.

FIG. 10 is a sectional view showing a second embodiment of the bolt tensioner according to the present invention.

FIG. 11 is a sectional view showing a third embodiment of the bolt tensioner according to the present invention.

[Explanation of symbols]

1, 1A, 1B, 1C, 20, 30 ... bolt tensioner, 2, 22, 32 ... tension member, 3, 3B, 3C, 2
3, 33 ... support member, 6, 6B, 6C, 26, 36 ... cylinder bore, 7, 7B, 7C, 27, 37 ... piston, 11, 11A ... fixed plate, 100, 100A ... flange, 102 ... top surface Part, 103, 103A ... bolt hole, 1
04, 104A: seat surface, 105: shoulder, N: nut,
V: bolt, S: spacer.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hitoshi Hashimoto 1-1-1, Wadazakicho, Hyogo-ku, Kobe-shi, Hyogo Nuclear Service Engineering Co., Ltd. (72) Inventor Atsushi Sasaki 615- Sakata, Hatsukaichi-shi, Hiroshima Prefecture 81 F term (reference) 3C038 AA01 AA09 EA04

Claims (11)

[Claims] The present invention is applied to mounting and removing a flange having a plurality of bolt holes arranged concentrically, and when tightening and loosening a nut screwed to a bolt passing through the bolt hole. A bolt tensioner for applying a tensile force to a bolt, comprising: a plurality of tension members capable of being coupled to the bolt; a support member capable of mounting the plurality of tension members on concentric circles; A bolt tensioner comprising: a cylinder bore portion; and a piston disposed in the cylinder bore portion, the piston separating the support member from the flange. 2. The bolt tensioner according to claim 1, wherein the piston operates as a reaction force receiving portion at an inner side of each bolt hole on the upper surface of the flange. 3. The bolt tensioner according to claim 2, wherein the support member is formed in an annular shape. 4. The bolt tensioner according to claim 3, wherein each of the cylinder bore and the piston are formed in an annular shape. 5. The apparatus according to claim 2, wherein said plurality of pistons are provided, and said cylinder bore is provided on a concentric circle and comprises a plurality of holes in which said pistons are provided. The bolt tensioner described in 1. 6. A fixing plate fixed to an upper surface of the flange located inside each of the bolt holes and supporting the supporting member, wherein the piston can contact the fixing plate. The bolt tensioner according to any one of claims 2 to 5, wherein: 7. The bolt tensioner according to claim 6, wherein the fixing plate rotatably supports the support member. 8. The nut has a substantially frustoconical outer shape, and is provided around an upper surface and each of the bolt holes so as to be located below the upper surface. The bolt tensioner according to any one of claims 1 to 7, further comprising: a plurality of seating portions that come into contact with the shoulder portion; and a shoulder portion located between the respective seating portions. 9. The bolt tensioner according to claim 1, wherein the piston operates at least one of the head of the bolt and the nut as a reaction force receiving portion. 10. The bolt tensioner according to claim 1, wherein the piston operates as a reaction force receiving portion with a seat portion provided around the nut with respect to the flange. 11. The apparatus according to claim 9, wherein the piston has a plurality of pistons, and the cylinder bore is formed of a plurality of holes arranged concentrically and in which the pistons are arranged. The bolt tensioner according to claim 10.