JPH0438954B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a joint structure for fluid pipes, and more specifically, the present invention relates to a joint structure for fluid pipes, and more specifically, to a gap between a large diameter pipe part (socket part) and a small diameter pipe part (insertion part). This invention relates to a structure for connecting two fluid pipes in which a packing having a self-sealing action is enclosed.

[Prior Art] FIG. 6 shows the structure of a conventional 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 attached 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 conjunction with the above, the packing is tightened so strongly that the packing loses its elasticity.
The flexibility of the joint portion is reduced. The packing and bolt are not watertight enough, and there is a risk of water leaking from this area. There are various problems such as.

[Technical Problems of the Present Invention] 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 effect and does not tighten the packing excessively. The technical problem is to obtain an improved joint by applying the packing to the joint structure described above.

[Configuration of the present invention] In order to achieve the above-mentioned technical problem, the fluid pipe joint structure of the present invention adopts the following configuration (technical means). That is, a socket portion having a packing accommodation space formed by an inner circumferential side wall and an inner vertical wall;
an insertion port that is inserted concentrically into the socket;
a packing press ring which is abutted against the outer end of the socket by a tightening tool and whose front packing press surface faces the packing accommodation space; The outer diameter is substantially equal to the outer diameter of the socket, and the outer diameter is substantially equal to the diameter of the inner circumferential side wall of the socket.
The wall thickness is substantially the same, the cross section is arcuate, and the outer and inner parts in the radial direction collide with the inner circumferential side wall of the socket and the outer circumferential surface of the socket at the tightening position. It is characterized by comprising an annular packing that is compressed in contact and exhibits a self-sealing effect.

[Function] The joint structure having the above configuration is implemented by the following connection operation, and exhibits the following function.

To connect the fluid pipes to each other, a packing press ring and packing are sequentially attached to the insertion part, and the insertion part is inserted into the socket. Next, the packing press ring is tightened using a tightening tool so that it abuts against the end of the socket. At this time, the packing pressing ring comes into contact with the packing and is pushed into the packing accommodation chamber, so that the packing is compressed in the tube axis direction and is pushed out in the tube radial direction, so that the packing is radially outward and inside. The end faces are in close contact with the inner circumferential side wall of the receptacle and the outer circumferential surface of the socket, respectively.

In the main joint section where the connection has been made, the pressure within the fluid pipe is transmitted to the packing accommodation space and further presses the packing, and as a result, the radially outer and inner end surfaces of the packing are exposed to the inner circumferential side wall of the socket section and the insertion section. It adheres closely to the outer peripheral surface and exhibits a good self-sealing effect.

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

When inserting the receptacle, the packing is held in a natural state (that is, in an uncompressed state), so that the receptacle can be inserted smoothly.

The packing exhibits self-sealing when tightened in place, so there is no deterioration of the packing.
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.

[Example] Examples of the present invention will be described below.

1 to 3 show an embodiment of the joint structure of the present invention. FIG. 1 shows the structure of the joint in the tightened position of the packing, FIG. 2 shows the structure of the joint in the natural state of the packing, and FIG. 3 shows the state when fluid pressure is applied.

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

Reference numeral 1A denotes an annular end fitting, which is watertightly fixed to the end of the socket 1 by other fixing means such as welding.

Reference numeral 11 denotes an outer flange formed on the end fitting 1A and stretched outside the socket 1. A plurality of bolt insertion holes 11a are bored in the outer flange 11 in the circumferential direction.

Reference numeral 12 denotes an inner flange formed on the end fitting 1A and stretched inward at a position recessed from the end of the socket 1. The inner diameter of the inner flange 12 is made larger than the outer diameter of the insertion part 2 with a margin, and the inner surface 121 is formed into a slope to compensate for flexibility in the joint part.

Reference numeral 13 denotes an inner peripheral side wall formed on the end fitting 1A, and is formed between the outer end surface of the outer collar 11 and the outer end surface of the inner collar 12. The inner circumferential side wall 13 is concentric with the tube axis, and its inner diameter is the same diameter (in other words, a surface parallel to the tube axis).

Reference numeral 14 denotes an inner vertical wall on the outer end surface of the inner collar 12, and the inner circumferential side wall 13 and the inner vertical wall 14 form a packing accommodation space H for accommodating packing, which will be described later.

Reference numeral 2 denotes the insertion portion of the other fluid pipe P′ which is inserted concentrically into the socket portion 1, and the end surface 21 of the insertion portion 2 does not require chamfering as in this embodiment. However, of course, this does not prevent chamfering.

3 is a packing press ring. Bolt insertion holes 3a are bored in the packing pressing ring 3 in the circumferential direction in correspondence with the bolt insertion holes 11a formed in the outer flange 11 of the socket part 1. Front surface 31 of the pressing ring 3
constitutes the pressing surface of packing. The inner diameter of the pressing ring 3 is larger than the outer diameter of the insertion port 2, and
Its inner surface 32 is formed into a slope to provide flexibility to the joint.

4 is a tightening tool, which includes a bolt 41 and a nut 4.
It consists of 2. 41a is the bolt head of the bolt 41, which engages with the end of the outer collar 11. The tightening tool 4 is installed across the corresponding bolt insertion holes 11a, 3a of the outer collar 11 and the packing press ring 3, and tightens the packing press ring 3 by rotationally tightening the nut 42.

5 is an annular packing arranged in the packing accommodation space H. The packing 5 has a C-shaped cross section with an arcuate shape, and has substantially the same wall thickness. 51 is a concave portion on the front surface of the packing 5, and 52 is a convex portion on the rear surface.

In a natural state (that is, in a non-compressed state), the packing 5 has a width in the tube axis direction that is longer than the depth of the packing accommodation space H, that is, the length of the inner circumferential side wall 13;
Its outer diameter is approximately equal to or slightly smaller than the diameter of the inner circumferential side wall 13 of socket portion 1, and its inner diameter is approximately equal to or slightly larger than the outer diameter of socket portion 2. .

In addition, in this embodiment, with the end fitting 1A,
The outer flange 11, the inner peripheral side wall 13, and the inner vertical wall 14 are configured, and the outer flange 11 and the inner flange 12 are connected to the socket part 1.
Of course, it can be formed separately and integrally formed with the socket.

The procedure of connection operation and water sealing effect of the joint structure of this embodiment will be described.

(1) For connection, deposit the packing press ring 3 and the packing 5 into the insertion port 2 in this order.

(2) Insert the insertion part 2 into the socket part 1, and pull the packing 5 and packing press ring 3 toward the socket part 1 side.

(3) Attach the tightening tool 4 to the socket 1 and the bolt insertion holes 11a, 3a of the packing press ring 3, rotate the nut 42 to lightly advance the packing press ring 3, and tighten the packing press ring 3. Pressing surface 31
collide with the rear surface 52 of packing 5 (second
(see figure). At this time, since the inner and outer diameters of the packing 5 maintain the predetermined natural dimensions, the packing 5 smoothly enters the packing accommodation space H.

(4) Packing press ring 3 by rotation of nut 42
The packing 5 is transferred to the packing accommodation space H through
Push it inside. At this time, the packing 5 is pinched between the inner vertical wall 14 of the inner collar 12 and the pressing surface 31 of the packing pressing ring 3, and is compressed in the tube axis direction, and expands in the radial direction, thereby packing the packing 5 into the outer and inner parts. The end faces come into close contact with the inner circumferential side wall 13 of the socket part 1 and the outer circumferential surface of the socket part 2, respectively (see FIG. 1).

(5) When the pressure p inside the fluid pipe acts on the joint connected by the above procedure, the pressure p propagates to the recess 51 of the packing 5, and the packing 5
is further compressed, and the packing 5 swells in the radial direction to perform a self-sealing action (see FIG. 3).

FIG. 4 shows 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, 7 is a cylindrical sleeve tube, and end fittings 1A are attached to both ends of the sleeve tube 7. The structures of the packing press ring 3, the fastening tool 4, and the packing 5 are similar to those of the previous embodiment. The sleeve joint device S is constituted by each of the above members.

The packing is not limited to that of this embodiment, and any packing may be used as long as it has a substantially arcuate cross section and provides the same effect. FIG. 5 shows an example of such packing 6. Figure 5a shows the natural state of the packing 6, and Figure 5b shows the packing 6.
Indicates the tightened state. Reference numeral 61 is a concave portion on the front surface of the packing 6, which receives fluid pressure within the fluid pipe.
Reference numeral 62 is a convex portion on the rear surface of the packing 6, which abuts against the packing pressing ring 3. Other symbols in the figures correspond to those in the previous drawings.

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.

To make a pressing surface of a packing press ring protrude and fit into a packing accommodation space.

The packing press ring is not only one piece, but also divided into two or more parts.

[Brief explanation of drawings]

1 to 5 show an embodiment of the joint structure of the present invention, FIG. 1 is a longitudinal cross-sectional view showing the packing of the embodiment in the tightened position, and FIG. 2 shows the packing of the embodiment. Fig. 3 is a longitudinal sectional view showing the state in a natural state, Fig. 3 is a longitudinal sectional view showing the state when hydraulic pressure is applied, Fig. 4 is a sectional view showing the structure of another embodiment (sleeve joint device), Fig. 5a , b are partial cross-sectional views showing the structure of still another embodiment. 6th
The figure is a sectional view showing the structure of a conventional joint part. 1... Socket part, 13... Inner peripheral side wall, 14...
Inner vertical wall, H... Packing accommodation space, 2...
Insertion port, 3... Packing pressing ring, 31... Packing pressing surface, 4... Tightening tool, 5... Packing.

Claims (1)

[Scope of Claims] 1. A socket 1 having a packing accommodation space H formed by an inner circumferential side wall 13 and an inner vertical wall 14, and a socket 2 inserted concentrically into the socket 1.
and a packing press ring 3 which is abutted against the outer end of the socket part 1 by a tightening tool 4 and arranged with its front packing press surface 31 facing the packing accommodation space H; The inner diameter is substantially equal to the outer diameter of the socket part 2 in the natural state, and the outer diameter is substantially equal to the diameter of the inner circumferential side wall 13 of the socket part 1. thick, has an arcuate cross section, and at the fixed tightening position, the outer and inner parts in the radial direction are the inner circumferential side wall 13 of the socket part 1.
and an annular packing 5 that is compressed against the outer circumferential surface of the insertion port 2 and exhibits a self-sealing action.