JPH022518B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a joint structure for fluid pipes, and more specifically, a packing having a self-sealing effect in the gap between a large diameter pipe part (socket part) and a small diameter pipe part (insertion part). This invention relates to the structure of a connecting part between two fluid pipes that are sealed with a fluid pipe.

FIG. 1 shows the structure of a prior art joint that is the object of the present invention. That is, a is the socket of one fluid pipe to be continued, b is the socket of the other fluid pipe, and c
is an annular flange fixed to the end of socket part a with bolts and nuts d, e is a packing inserted into socket part a, and f is a tightening ring attached to the back of packing e. , g is a bolt whose end is fixed to the tightening ring f and passes through the packing e and the flange c, and h is a nut screwed onto the bolt g. In this structure, by rotating and tightening the nut h, the tightening ring f is drawn toward the flange c, and the packing e is compressed and deformed by the flange c and the tightening ring f, and the inner surface of the socket part a and the insertion It comes into pressure contact with the outer surface of the mouth part b.

However, in the above-mentioned conventional technology, since the packing exerts its watertight action by its surface pressure (in other words, it takes a mechanical type of watertight action), it is necessary to tighten the packing strongly, and the tightening requires a large amount of effort. Power is needed. For this reason,
The number of bolts increases and processing time is added.
Coupled with the above, the packing is strongly tightened, and due to the excessive internal stress, the packing gradually deteriorates over a long period of time and loses its watertight effect.
In combination with the above, the packing is tightened so strongly that the packing loses its elasticity.
The flexibility of the joint portion is reduced. There are various problems such as insufficient watertightness between the packing and the bolt, and there is a risk of water leaking from this part.

The present invention has been made to overcome the drawbacks of the above-mentioned prior art, and focuses on self-sealing packing that has excellent water-sealing properties and does not overtighten the packing, and applies this packing to the above-mentioned joint structure. The technical problem is to obtain an improved joint by doing so.

The fluid pipe joint structure of the present invention adopts the following configuration (technical means) in order to achieve the above technical problem.
That is, the inner surface of the socket part 1, the outer surface of the socket part 2 that is inserted concentrically into the socket part 1, and the flange 3 that is stretched from the end surface of the socket part 1 while maintaining watertightness. At the connection part of the fluid pipe which forms an annular packing accommodation space H with the inner surface 32 of the bolt head 4
1 and a bolt rod 42 with a screw 422, from the outside of the flange 3, leaving the bolt head 41 outside, maintaining watertightness with the bolt rod insertion hole 3A of the flange 3, and inserting it into the packing accommodation space H. The threaded bolt rod 42 is rotatably inserted into the bolt rod 42, and the portion of the bolt rod 42 that is inserted into the bolt insertion hole 3A of the flange 3 has a large diameter 421, and the length of the bolt insertion hole 3A is made large. The required number of tightening bolts 4 whose length α is increased as appropriate
is disposed in the packing accommodation space H and consists of a radially outer heel portion 61 and an inner valve portion 62, and the heel portion 61 has a large diameter portion 421 of the bolt rod 42 of the tightening bolt 4. A cap 63 is embedded into which the valve portion 62 is inserted, and when it is tightened at the fixed position, the valve portion 62 collides with the inner surface 32 of the flange 3 and the outer surface of the insertion portion 2 to perform a self-sealing action. The bolt 4 is screwed into the thread 422 of the bolt rod 42, and the tightening rotation of the tightening bolt 4 causes the packing 6 to be tightened.
and a drawing means for drawing the flange 3 toward the inner surface 32 side of the flange 3.

The joint structure having the above configuration is implemented by the following connection operation, and has the following functions.

When connecting fluid pipes to each other, first attach a packing to the tightening bolt inserted into the socket through the flange, and lightly tighten the tightening valve until the valve part of the packing comes into contact with the inner surface of the flange ( (This is referred to as a temporarily fixed state.) As a result, the flange, tightening bolt, and packing are fixed to the receptacle as a set, and they do not move inadvertently.

Next, when the insertion part of the fluid pipe to be connected is inserted into the socket part and the tightening bolt is rotated in the tightening direction, the valve part of the packing will reduce its inner diameter as it collides with the inner surface of the flange, and the insertion part will be reduced. Impact compression occurs on the outer surface of the mouth. Then, the tightening of the tightening bolt is stopped at a position where the packing effectively exhibits a self-sealing action (this is referred to as a fixed tightening position).

At the joint where the connection has been made, the pressure within the fluid pipe acts on the valve part of the packing not only from the inside of the packing housing space (i.e. from the back of the valve part) but also from the front of the heel part of the packing. It goes around and acts from the outside in the radial direction of the valve part, and as a result, the valve part of the packing comes into close contact with the inner surface of the flange and the outer surface of the insertion part, and exhibits a good self-sealing effect.

The joint structure of the present invention has the following unique effects.

Since the flange, tightening bolt, and packing can be assembled into the socket part as one unit, they can be transported while being assembled to the socket part, and the connection operation becomes easy.

When inserting the socket, the packing is held in a natural state (that is, not compressed), so the insertion of the socket can be done smoothly.The valve part of the packing is tightened in the fixed position. Since it exhibits self-sealing, there is no deterioration of the packing, and the water-sealing effect can be maintained for a long period of time.

Coupled with the above effects, flexibility is ensured by the valve portion that exhibits a self-sealing action, and the flexibility of the joint is not impaired.

The present invention further enhances its effects by adopting the following aspects.

When tightened in place, a fluid passage should be formed between the heel of the packing and the inner surface of the flange by appropriate means. According to this aspect, the packing is not tightened excessively, the fluid pressure acts effectively on the valve portion of the packing, and the valve portion can exhibit a good self-sealing action.

The inner diameter of the valve part of the packing shall be substantially larger than the outer diameter of the insertion part in its natural state (uncompressed state). In other words, the inner diameter of the valve part should be the same as the outer diameter of the socket, or it should be slightly larger. According to this aspect, when connecting the fluid tubes to each other, the insertion operation of the insertion port is smoothly performed without receiving resistance from packing. Therefore, there is no need to chamfer the end face of the insertion port.

The pulling means shall be a cap embedded in the heel of the packing or a tightening ring placed on the back of the packing.

Examples of the present invention will be described below.

2 and 3 show an embodiment of the joint structure of the present invention. FIG. 2 shows the structure of the joint in the tightened position of the packing, and FIG. 3 shows the structure of the joint in the natural state of the packing.

Reference numeral 1 denotes a socket at the end of one of the fluid pipes P to be connected, and its diameter is increased.

2 is the other fluid pipe inserted into the socket 1
The end face 21 of the insertion opening 2 of P' is not chamfered.

Reference numeral 3 designates an annular flange extending inward from the end surface of the socket portion 1 . The flange 3 is fixed to the end face of the socket part 1 by welding, but it is essential to maintain watertightness, and other suitable fixing means can be used as long as watertightness can be maintained. The inner diameter of the flange 3 is made slightly larger than the outer diameter of the insertion port 2 to ensure flexibility at the joint. Reference numeral 3A denotes bolt rod insertion holes for tightening bolts, which will be described later, which are bored at appropriate intervals (usually at equal intervals) in the circumferential direction of the flange 3.

The above-mentioned socket part 1, socket part 2, and flange 3 constitute a packing accommodation space H.

Numeral 4 is a tightening bolt, which consists of a bolt head 41 and a bolt rod 42. The bolt rod 42 is also
It is composed of a large-diameter rod portion 421 connected to the bolt head 41 and a threaded portion 422 at the tip.

The large-diameter rod portion 421 is inserted into the bolt insertion hole 3A of the flange 3, and the O-ring 5 arranged in the gap is inserted into the bolt insertion hole 3A of the flange 3.
Ensure watertightness. In this embodiment, the O-ring 5 is a concave groove 4 bored around the large-diameter rod portion 421.
It is attached to 23. Further, the length of the large diameter rod portion 421 is set to be an appropriate length (α) larger than the length of the bolt insertion hole 3A (in other words, the plate thickness of the flange 3).

Reference numeral 6 denotes an annular packing disposed in the packing accommodation space H, which consists of a heel part 61 on the outside and a valve part 62 on the inside (see FIG. 4).

The heel portion 61 is made of hard rubber, and the threaded portion 422 of the tightening bolt 4 is inserted at an appropriate position in the circumferential direction of the heel portion 61.
The cap 63 has an insertion hole 6A inserted into the loosely inserted state.
is embedded. The cap 63 abuts against the stepped portion of the large-diameter rod portion 421 of the tightening bolt 4 at the fixed tightening position, and prevents the packing 6 from being excessively compressed.

The valve part 62 is compressed in the tightened position and comes into close contact with the outer surface of the insertion part 2 and the inner surface 32 of the flange 3,
It exhibits a self-sealing effect in response to fluid pressure within the fluid pipe. The valve portion 62 has a shape bent toward the flange 3 from the heel portion 61 in its natural state (uncompressed state), and its inner diameter is substantially equal to the outer diameter of the insertion portion 2 or smaller. The diameter is made slightly larger than that of the 62a is a concave groove with a semicircular cross section formed continuously on the back surface of the valve portion 62,
Fluid pressure acts on the groove 62a, improving the self-sealing effect of the valve portion 62.

Reference numeral 7 denotes an annular tightening ring disposed on the back of the packing 6, which is divided into two or more parts, but may be a single piece. A female screw hole 7A is formed at an appropriate position in the circumferential direction (that is, a position corresponding to the bolt rod insertion hole 3A of the flange 3 and, in turn, the insertion hole 6A of the packing 6), and is screwed into the screw 422 of the tightening bolt 4. Therefore, the rotation of the tightening bolt 4 causes the tightening ring 7 to advance toward the flange 3 side.

In this embodiment, the pulling means is constituted by the tightening ring 7 in a narrow sense, but in a broader sense, it is constituted by a cap 63 embedded in the heel portion 61 of the packing 6 and a large diameter rod of the tightening bolt 4 that collides with the cap 63. Section 42
1 is also included.

Next, we will describe the connection operation procedure and water sealing effect of the joint structure of this embodiment. After each of the divided tightening ring 7 and packing 6 is carried in, the tightening ring 7 is assembled as one piece.

(2) Insert the tightening bolt 4 into the bolt rod insertion hole 3A from the outside of the flange 3. At this time, an O-ring 5 is attached to the groove 423 of the large-diameter rod portion 421 of the tightening bolt 4 to ensure watertightness (airtightness) with the bolt rod insertion hole 3A of the flange 3. Next, the bolt rod 42 of the tightening bolt 4 is inserted and screwed into the insertion hole 6A of the packing 6 and the female threaded hole 7A of the tightening link 7.

(3) Rotate the tightening bolt 4 to lightly move the tightening ring 7 forward until the front end of the valve 62 of the packing 6 comes into contact with the inner surface 32 of the flange 3 (see Fig. 3). In this state, the tightening bolt 4, packing 6, and tightening ring 7 are integrally assembled to the socket 1, and are in a temporarily fixed state.

(4) Next, insert the insertion tube 2 into the socket 1.
At this time, since the inner diameter of the valve portion 62 of the packing 6 is substantially equal to or slightly larger than the outer diameter of the insertion tube 2, the insertion tube 2 can be inserted smoothly.

(5) After that, when the bolt head 41 of the tightening bolt 4 is rotated to further push the tightening ring 7 toward the flange 3, the valve portion 62 of the packing 6 collides with the inner surface 32 of the flange 3 and is compressed. By reducing the wall diameter of the valve portion 62, it also comes into close contact with the outer surface of the insertion port 2. When the tightening ring 7 is further pulled, the cap 63 of the heel portion 61 of the packing 6 collides with the large diameter rod portion 421 of the tightening bolt 4, preventing further excessive compression of the valve portion 62 of the packing 6. A fluid conduction path having a width α is formed between the heel portion 61 and the inner surface 32 of the flange 3 (see FIG. 2).

(6) When the pressure inside the fluid pipe acts on the joint part connected by the above procedure, the pressure acts directly on the inside of the valve part 62 of the packing 6, and also acts through the fluid passage of the heel part 61. It also acts from the outside of the valve part 62, and the valve part 62 of the packing 6 exhibits a water-sealing effect by self-sealing action.

5 and 6 show an embodiment in which the joint structure of the present invention is applied to a sleeve joint device. The same reference numerals are given to the same members as those in the above-described embodiment.

Here, 8 is a cylindrical sleeve tube, and flanges 3 are attached to both ends of the sleeve tube 8.
Tightening bolt 4, packing 6, tightening ring 7
The structure of is similar to the above embodiment. The sleeve joint device S is constituted by each of the above members.

FIG. 5 shows the assembled state of the sleeve joint device S, which is assembled in this state at the factory and transported to the site in this state. In this assembled state, the sleeve joint device S is in a fixed state with no play as a whole, making it suitable for transportation. When the insertion port 2 (indicated by dotted lines) is inserted in this state, the inner diameter of the packing 6 is larger than the outer diameter of the insertion port 2, so that the insertion operation is performed smoothly.

FIG. 6 shows a state in which the tightening bolt 4 of the sleeve joint device S is completely tightened. That is,
As the bolt head 41 of the tightening bolt 4 is rotated to pull the tightening ring 7, the tightening ring 6
The valve portion 62 is pressed against the inner surface of the flange 3 and is pushed in while its diameter is reduced. Then, the front end surface of the cap 63 of the packing 6 comes into contact with the stepped portion of the large-diameter rod portion 421 of the tightening bolt 4, at which point the tightening position is reached, and the connection operation is completed.

The present invention is not limited to the above-described embodiments, and various design changes can be made within the scope of the basic technical idea of the present invention. That is, the following aspects are included within the technical scope of the present invention.

In the above embodiment, the threaded portion 42 of the tightening bolt 4
2 and the tightening ring 7 are in a screwing relationship, and the threaded portion 422 of the tightening bolt 4 and the cap 63 of the packing 6 can be screwed together. In this case, the tightening ring can be dispensed with. Furthermore,
By setting the threaded portion to an appropriate length, the extra length α of the large diameter rod portion 421 of the tightening bolt 4 can be omitted.

The cross-sectional shape of the heel part and the valve part of the packing is not limited to the dogleg shape of the above embodiment;
As shown, the valve portion can have a round cross section. In this case, it is preferable that the tightening ring 7 adopts a mode in which the inner diameter portion (the surface with which the valve portion of the packing comes into contact) is bent.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the structure of a conventional joint. Figure 2 and the following diagrams show embodiments of the joint structure of the present invention. Figure 2 is a sectional view showing one embodiment in a tightened position, and Figure 3 shows it in a temporarily tightened state. 4 is a partial side sectional view of a packing used in the embodiment, FIGS. 5 and 6 are sectional views showing the structure of another embodiment (sleeve joint device), and FIG. The figure is a partially sectional view showing the structure of yet another embodiment. 1...Socket part, 2...Socket part, 3...Flange, 3A...Bolt rod insertion hole, 32...Inner surface, 4
...Tightening bolt, 42...Bolt rod, 422...
...Threaded part, 6...Packaging, 61...Heel part, 62...Valve part, 7...Tightening ring, H
...Patsuking accommodation space.

Claims (1)

[Scope of Claims] 1. The inner surface of the socket part 1, the outer surface of the socket part 2 which is inserted concentrically into the socket part 1, and the end surface of the socket part 1 to maintain watertightness. At the connection part of the fluid pipe that forms an annular packing accommodation space H with the inner surface 32 of the flange 3 provided, the bolt head 41 and the bolt rod 42 with a screw 422 are provided, and the bolt is inserted from the outside of the flange 3. The threaded bolt rod 42 is rotatably inserted into the packing accommodation space H while keeping the head 41 outside and maintaining watertight contact with the bolt rod insertion hole 3A of the flange 3.
is inserted, the bolt rod 42 has a large diameter 421 at the portion inserted into the bolt insertion hole 3A of the flange 3, and has a length (α) appropriately larger than the length of the bolt insertion hole 3A. a required number of tightening bolts 4, and a radially outer heel portion 61 and an inner valve portion 62 disposed within the packing accommodation space H;
A cap 63 that is inserted through the bolt rod 42 other than the large diameter portion 421 is embedded, and when the valve portion 62 is tightened at the fixed position, the valve portion 62 is inserted into the inner surface 32 of the flange 3 and the insertion portion 2.
a packing 6 which exhibits a self-sealing action by being compressed against the outer surface of the bolt; and a thread 42 of the bolt rod 42 of the tightening bolt 4.
2, and by tightening and rotating the tightening bolt 4, the packing 6 is attached to the inner surface 32 of the flange 3.
A fluid pipe joint structure characterized by comprising a pulling means for pulling the fluid pipe to the side. 2. The fluid pipe joint structure according to claim 1, wherein the heel portion 61 of the packing 6 forms a fluid passage with the inner surface 32 of the flange 3 in the tightened fixed position. 3. The fluid pipe joint structure according to claim 1 or 2, wherein the inner diameter of the valve portion 62 of the packing 6 is substantially larger than the outer diameter of the insertion port 2 in a natural state. 4. The fluid pipe joint structure according to any one of claims 1 to 3, wherein the drawing means is a cap 63 having a female screw embedded in the heel portion 61 of the packing 6. 5. The fluid pipe joint structure according to any one of claims 1 to 3, wherein the pulling means is a tightening ring 7 having a female thread disposed on the back of the packing 6.