JP2000009874A - Clamping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a uniform joint force over the entire circumference even in the initial stages of clamping, in a clamping device for clamping and joining opposed annular flanges. SOLUTION: The clamping device 30 for clamping and joining two tubular opposed annular flanges being arranged coaxially is provided with a center- clamping link 31 and opposed clamping links 33 and 35 for constituting a clamping and fixing metal in a four-node link structure being arranged along the outer periphery of the annular flange F and contact clamping pieces 49, 51, and 53 where each rear surface part is supported by the center clamping link 31 and the opposing clamping links 33 and 35 so that they can be rocked freely. In this case, the opposing clamping links 33 and 35 are clamped at one point by a clamping tool consisting of a clamping bolt 39, a clamping nut 41, and pins 43 and 45.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clamp device, and more particularly, to a clamp device for binding and joining two opposed coaxially disposed annular flanges of a tubular body.

[0002]

2. Description of the Related Art Two tubular bodies, such as pipes, which are arranged coaxially and each have a flange at its end, can be fastened and released quickly, and the installation space is relatively small. There is a need for a clamp device that can be used. For example,
In a pressurized water reactor, such a clamp device is used in a take-out tube of a thermocouple for detecting a temperature inside the reactor. Referring to FIG. 8, the nozzle 1, the connecting pipe 3, and the take-out pipe 5 fixed to the reactor vessel head (not shown) are coaxially arranged. An annular sealing material 7 is interposed between the joining flange 1a at the upper end of the nozzle 1 and the joining flange 3a at the lower end of the connecting pipe 3.
When a and 3a are joined and fastened, they exhibit a predetermined sealing function. Furthermore, the flange 5a at the lower end of the take-out conduit 5
An annular sealing material 9 is also interposed between the annular sealing member 9 and the inner flange 3b at the upper end of the connecting pipe 3, and has the same sealing function as the annular sealing material 7.

[0003] Since the nozzle 1 and the connecting pipe 3 are provided in a narrow space, the connecting flanges 1a and 3a need to be joined together.
A clamping device 10 as shown in FIGS. 9 and 10 is used. The clamp device 10 includes the joining flanges 1a, 3
a, four clamp pieces 11, 13,
15, 17, these clamp pieces 11, 13, 15, 17
And a connecting plate 19, a pivot pin 21, a retaining pin 23, a tightening bolt 25 and a tightening nut 27. Then, when the tightening nut 27 is tightened, the clamp pieces 11, 17 approach each other first, and as a result, the respective tightening contact surfaces 11a, 13a, 15a, 17a of the clamp pieces 11, 13, 15, 17 are defined. Since the diameter of the formed inscribed circle becomes smaller, the joining flanges 1a and 3a are brought closer to each other to join them. Since the annular sealing member 7 is made of an elastic material, when the joining flanges 1a and 3a approach each other, the annular sealing member 7 is elastically deformed and a predetermined contact pressure is generated on the contact surface with the joining flanges 1a and 3a. Then, sealing is performed.

[0004]

In the above-described structure of the conventional clamping device 10, the tightening bolt 25 and the tightening nut 2 are used.
When the joint 7 is fully tightened, there is no gap between the joint flanges 1a and 3a as shown in the graph of FIG. 11, but in the initial stage of fastening, the joint flange 1a on the tightening bolt 25 side. , 3a are fastened quickly,
Since the portion farthest from the tightening bolt 25 is finally tightened, an inclination occurs between the joining surfaces of the joining flanges 1a and 3a, which causes a variation in the sealing performance of the annular sealing material 7 in the circumferential direction.
It was the cause of the failure. And, as a characteristic of the annular sealing material, since the sealing direction is the radial direction of the inner and outer circumferences, when the inclination or the like occurs, the sealing surface pressure tends to be non-uniform due to excessive deformation of the sealing material. Further, since the interior of the nozzle 1 communicates with the high-temperature and high-pressure coolant space in the reactor vessel, when this pressure increases, as shown in the graph of FIG. The gap (opening amount) between them increases, and when the gap reaches a predetermined amount, the sealing function is lost and the internal fluid leaks. Various causes can be considered as causes of these inconveniences. However, the conventional clamping device has four clamp pieces 11, 13, 15, 17 and 3
Since the connecting plates 19 are multi-jointed links sequentially connected, various positions can be taken (with a large degree of freedom) according to the resistance to displacement, etc., except for the link nodes at both ends. Accordingly, an object of the present invention is to provide a link-type clamp device which is fastened at one place, wherein the position and posture of each link member constituting the clamp device are uniquely determined by the amount of fastening, and the entirety of the flange to be joined is determined. An object of the present invention is to provide a clamp device capable of obtaining a uniform and stable joining force over the circumference.

[0005]

According to the present invention, there is provided, in accordance with the present invention, a multi-joint link type clamping device for binding and joining opposing annular flanges of two coaxially disposed tubular bodies. A plurality of joints connected in sequence, preferably four joints, and four links, and a fastening metal fitting arranged along the outer periphery of the annular flange; Of the inner peripheral side is supported on the back side of the inner peripheral side so as to be swingable, and the tightening and fixing bracket is fastened at one place by the fastener.

[0006]

Embodiments of the present invention will be described below with reference to the accompanying drawings. First of all, referring to FIG. 1, the tightening link structure of the clamping device 30 according to the present invention includes a fastening fixture, that is, a center fastening link 31 and an opposed fastening link 3.
3 and 35 and two connecting pins 37 for connecting these pivotally. The center tightening link 31 has a line-symmetrical shape, and has a forked portion provided with a pin hole for the connection pin 37 at both ends. Furthermore, the opposing fastening links 33, 35
Have similar shapes and dimensions. As is obvious from this configuration, the opposing tightening links 33 and 35 can pivot about the connecting pins 37 at both ends of the center tightening link 31 in opposite directions, and can be freely opened and closed. The opposing fastening links 33, 35 are also provided with bolt holes in a plane perpendicular to the central axis of the pivot (a plane parallel to the plane of the drawing), through which fastening bolts 39 are inserted. Further, a fastening nut 41 is screwed into the fastening bolt 39. Furthermore, the head of the fastening bolt 39 and the opposed fastening link 3
Between the receiving seats 3 and the fastening nut 41 and the opposed fastening link 3
Pins 43, 45 are interposed between the receiving seats 5 so that equal tightening forces act on the receiving seats of the opposing tightening links 33, 35. As can be understood from the above description, the connection pin 37 is a rotary joint in the link mechanism, and the bolt hole through which the fastening bolt 39 passes is a smooth joint.

As described above, the center tightening link 31 and the opposing tightening link 3 connected to form a link mechanism.
Fastening fittings, that is, contact fastening pieces 49, 51, 53 are supported on the inner peripheral sides of the pins 3, 35 via pins 47 so as to swing freely. The contact fastening pieces 49, 51, 53 are preferably formed in the same shape and size, and are circles having a wedge-shaped cross section for receiving the outer peripheral portion of the flange F to be joined (only the outer shape is shown by a two-dot chain line). It has a circumferential groove. The flange F to be joined is equivalent to the joining flanges 1a and 3a in FIG. The pins 47 that support the contact fastening pieces 49, 51, 53, respectively, so as to swing freely are preferably arranged at equal intervals along the outer circumference of the joining flange F.
Further, the contact fastening pieces 49, 51, and 53 are also provided with pins 4 at the center.
7, the contact angle with the joint flange F is approximately 90 degrees.

A procedure for tightening the clamp device 30 having the above-described configuration will be described with reference to FIG. (A) The figure shows that when the clamp device 30 is set around the flange F and is attached from the axial direction, the contact fastening pieces 49, 51, and 5 are used.
Each of the inner ends 3 is at least outside the outer peripheral end of the flange F, and the fastening nut 41 is not screwed to the fastening bolt 39. In this case, the center of the flange F and the contact fastening piece 49,
The offset P from the center of the circle defined by 51 and 53 is the largest. When the opposing fastening links 33, 35 are brought closer to each other, the offset P is slightly reduced, and the contact fastening pieces 49, 51,
53 slightly overlaps with the joining flange F ((b)
If the overlap amount is further increased, as shown in (c), the fastening nut 41 can be screwed into the fastening bolt 39. When the fastening nut 41 is tightened, the gap between the open / close end portions of the opposed fastening links 33 and 35 gradually decreases, and the offset P is shown in FIGS.
(F) It decreases in the order of the figure. In the state shown in FIG. 3 (f), the offset P is lost and is not shown. The contact tightening pieces 49, 51, 53 are sufficiently incorporated in the outer peripheral portion of the flange F to provide sufficient contact with the seal therebetween. A pressure is applied and the flange F is joined.

Now, as shown in FIG.
Opposed fastening link 35 acting on the flange F through 1,53, respectively inward acting force of the center fastening link 31 and the counter fastening link 33 When _L 1, _{L 2} and _{L 3,} the load sharing ratio L ₃ / L ₁ gradually rises with respect to the flange portion entry amount S as shown by the solid line in the graph of FIG. For reference, a change line of the corresponding load sharing ratio in the conventional one is shown by a broken line in FIG. That is, the load sharing ratio _L 3 / _{L 1} is in the present invention while varying from 0.6 to 1.0, than the conventional varies from 0.45 to 1.0. As can be seen from the above, in the present invention, the difference in the shared load of the component fastening links is small, and uniform fastening is performed.
Further, since the contact fastening pieces 49, 51, 53 are in the form of a balanced beam and supported by pins, the friction which has conventionally occurred in the radial direction and the circumferential direction at the contact portion with the flange is only in the radial direction. In addition, a uniform joining force can be obtained at the contact portion.
The total contact length of the contact fastening pieces 49, 51, 53 with the flange F is 270 degrees, which is 1.4 times that of the conventional 200 degrees.
As a result, the spread between the flanges F due to an increase in the internal pressure is reduced.

Next, another embodiment will be described with reference to FIGS. 5, 6 and 7. FIG. First, in FIG. 5, the clamp device 60 includes clamp members 61, 63 having symmetrical shapes.
A clamp fitting 65 located between them, a connecting fitting 67 for pivotally connecting the clamp fitting 65 and the clamp fitting 61 or 63, pins 69 at both ends, and a clamp fitting 6.
Tightening bolts 71 inserted into the tightening ends of the first and third bolts, the fastening nuts 73 to be screwed thereto, and the clamp 6
1 and 63, and rollers 75 interposed between the tightening bolt 71 and the tightening nut 73, respectively. Tightening bolt 71, fastening nut 73, and roller 7
5 is a fastening tool.

A groove having a wedge-shaped cross section is formed on the inner peripheral end side of each of the clamp fittings 61, 63, and 65. As shown in FIG. The flange 1a and the joining flange 3a of the connecting pipe 3 are in contact with the wall surface of the groove 61a. On the other hand, between the joining flanges 1a and 3a,
Is interposed, and the joining flange 1 is
When a and 3a come close to each other, the sealing is performed in close contact with the joint surface. An outline of the structure of the helicopter seal 8 is shown in FIG.
It is composed of an outermost soft metal outer plate 8b and an intermediate inner plate 8c. A typical soft metal is silver.

The circumferential contact angle α (FIG. 5) at which the wall surface of the groove 61a of the clamp fitting 61 contacts the joining flanges 1a and 3a is set to about 100 °, and three clamp fittings 6 are provided.
The total angle of 1, 63 and 65 is about 300 °.
The dimensions of each part are set so that the positions of the pin 69 and the roller 75 in the final tightening state are equal to the center position, that is, the center axis of the nozzle 1. Therefore, if the tightening nut 73 screwed to the tightening bolt 71 is tightened up, the joining flanges 1a, 3a are uniformly tightened over the entire circumference, and the helicflex seal 8 is uniformly compressed. Thus, an appropriate sealing action can be obtained.
In particular, the outer plate 8b made of a soft metal is easy to fit into the joint surface, and the inner plate 8c averages the reaction force of the coil spring 8a and transmits it to the outer plate 8b, so that a good sealing action is ensured without any contact. Is done.

[0013]

As described above, according to the present invention,
Since the clamping device is constituted by a multi-joint link structure and the number of the joints is small, preferably four, the joining force acting on each link becomes uniform, and the outer peripheral edge of the annular flange to be joined is formed. Since the joints are tightened equally, it is possible to prevent the inclination of the joining surface from occurring, and to secure appropriate sealing performance over the entire circumference. Furthermore, according to the present invention, since the contact length of the fastener that comes into contact with the annular flange can be increased as a whole, the deformation resistance to the pressure increase inside the flange increases, and the occurrence of leakage can be prevented. .

[Brief description of the drawings]

FIG. 1 is a partially cutaway plan view showing an embodiment of the present invention.

FIG. 2 is an operation explanatory diagram for explaining the operation of the embodiment step by step.

FIG. 3 is a conceptual diagram showing an operation state of a tightening force in the embodiment.

FIG. 4 is a graph for explaining the operation of the embodiment.

FIG. 5 is a plan view showing another embodiment of the present invention.

FIG. 6 is a partial cross-sectional view of the another embodiment.

FIG. 7 is a partial perspective view showing a part of FIG.

FIG. 8 is a partial vertical sectional view showing an example of an application in which the clamp device according to the present invention is used.

FIG. 9 is an overall plan view showing a conventional clamping device.

FIG. 10 is a sectional view taken along line XX of FIG. 9;

FIG. 11 is a graph illustrating the operation of the conventional device.

FIG. 12 is a graph illustrating another operation of the conventional device.

[Explanation of symbols]

Reference Signs List 30 clamp device 31 center tightening link 33, 35 opposed tightening link 37 connecting pin 39 tightening bolt 41 tightening nut 43, 45, 47 pin 49, 51, 53 contact tightening piece 60 clamp device 61, 63, 65 clamp bracket 67 connecting fitting 69 pin 71 tightening bolts 73 tightening nut 75 roller F flange L _{1, L} 2, _{L 3} acting force P offset

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshihisa Fujiwara 2-1-1 Shinama, Arai-machi, Takasago City, Hyogo Prefecture Inside the Mitsubishi Heavy Industries, Ltd. Takasago Research Laboratory (72) Inventor Kazunobu Hashida 2-1-1, Araimachi Shinama, Takasago-shi, Hyogo Prefecture 1 Takasago Research Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Inventor Tomonobu Sato 1-1-1, Wadazakicho, Hyogo-ku, Kobe, Hyogo Prefecture Inside Kobe Shipyard, Mitsubishi Heavy Industries, Ltd. (72) Inventor, Kiminobu Hojo Araimachi, Takasago-shi, Hyogo 2-1-1, Shinhama Inside Takasago Research Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Inventor Yasuhiro Kutomi 1-1-1, Wadazakicho, Hyogo-ku, Kobe-shi, Hyogo F-term (reference) 3J022 BF02 3J039 AA02 BB01 CA04 GA03

Claims (4)

[Claims] 1. A clamping device for tightly joining opposed annular flanges of two tubular bodies arranged coaxially, wherein a plurality of nodes are fastened and fixed along a periphery of the annular flange. And a clamp on the inner peripheral side, the back surface of which is swingably supported by the clamp for fixing, wherein the clamp for fixing the clamp is fixed at one place by the clamp. 2. The clamping device according to claim 1, wherein the fastening member has a back surface supported by the fastening fixture via a pin, and the pin is evenly arranged in a circumferential direction. 3. The clamp device according to claim 1, wherein the fastening fixture is formed by directly pin-joining a plurality of arc-shaped members, and the fastening tool comprises a combination of a bolt and a nut. 4. A clamping device for binding and joining opposed annular flanges of two coaxially disposed tubular bodies, wherein the clamp device is arranged along the outer periphery of the opposed annular flanges with a helicflex seal interposed therebetween. Three fastening fixtures, two connecting fittings disposed between the adjacent fastening fixtures and pivotally connecting the fastening fixtures via pins, A fastener that is disposed between the fastening fasteners and that fastens the three fastening fasteners connected at one place, wherein the fastening tool includes a combination of a bolt and a nut and a roller that contacts the fitting. Become a clamping device.