JPH0544631Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to an improvement of the joint structure of synthetic resin pipes, and more specifically, to make it compatible with the expansion and contraction of synthetic resin pipes and to improve workability. The present invention relates to a joint structure for synthetic resin pipes, characterized by the following.

(Prior Art and Issues) Synthetic resin pipes such as polyethylene pipes are used for sprinkler pipes for field irrigation or temporary pipes for civil engineering construction work. Conventional methods for joining synthetic resin pipes include the flange joining method and the cold joint method (JWWA). When used in agriculture, piping work is often done on the ground, which means that it is removed, moved to another location, and then reinstalled and used. The above joining method has problems such as complicated assembly and disassembly work, occurrence of co-rotation during disassembly, deformation of parts, and damage to synthetic resin tubes, making it difficult to use them again. Therefore, a welded type one-touch pipe joint was developed that is easy to assemble and disassemble. This has problems, such as the need to weld, for example, a polyethylene pipe to one of the male and female joints, and the lack of play in the joint, making it impossible to cope with the expansion and contraction of the polyethylene pipe due to differences in temperature. In view of the above, the inventors of the present application
-166712, disclosed as Utility Model Application No. 62-58508.
The present invention is a further improvement, and aims to provide a joint structure for synthetic resin pipes that has a small number of parts, is easy to assemble and disassemble, and can handle the expansion and contraction of synthetic resin pipes. be.

(Means for solving problems) The present invention will be explained with examples.

As shown in FIGS. 1 and 2, one of the coupling parts consists of a joint body 1, a latch ring 2, and a synthetic resin pipe 3 to be connected. The joint body 1 has an annular groove 4 on the inner peripheral side of its end, and a U-shaped packing 5 is disposed in this groove 4. The watertightness of the U-shaped gasket 5 increases as the water pressure increases.

A hook engaging groove portion 7 is formed in the outer peripheral wall surface 6 of the end portion of the joint body 1. Preferably, a plurality of hook engaging grooves 7 are provided facing each other.

As shown in FIG. 3, there is a first convex portion 8 extending in the circumferential direction on the outer peripheral surface of the end of the joint body 1, and from one end of the first convex portion 8 to the other end of the joint body 1. A second protrusion 9 extending to the side in the axial direction and a third protrusion that is substantially parallel to the second protrusion 9 from the other end and shorter than the second protrusion 9. It consists of a section 10.

As shown in FIG. 3, in order to prevent the hook 11 from coming off the hook engaging groove 7 during use,
The protrusion 1 with a distance t ₀ between the front end of the protrusion 10 and the front end of the protrusion 1
2 is provided, and the distance t ₀ is the thickness t ₁ of the engaging part of the hook 11
By making it slightly larger, the hook 11 can be made difficult to separate from the groove 7 due to vibration or the like during use. Also, the length of the U-shaped bottom a of the hook 11 is equal to the width b of the first protrusion 8 of the joint body 1.
By making the length longer than that, play 18 is provided between the joint body 1 and the latch ring 2.

The synthetic resin tube 3 is expanded to form a step 14 by press-fitting a core 13 having an outer diameter larger than the inner diameter of the synthetic resin tube 3 into the inner surface of the end portion of the synthetic resin tube 3.

The latch ring 2 has a hook 11 at one end that engages with the hook engaging groove 7 of the joint body 1, and an annular groove 15 on the inner circumferential side of the other end. A lock ring 16 and a stop ring 17 are installed in the groove 15.
is provided, and the lock ring 16 and the groove 15 are in a loose relationship. The latch ring 2 is in a loose relationship with the synthetic resin pipe 3 and is rotatable.
The hook 11 of the latch ring 2 has a substantially U-shaped cross section that opens toward the inner circumference, and as shown in FIG.
1 into the groove 7 from the third protrusion 10 side while rotating in the direction of arrow A, and then moved in the direction of arrow B and placed between the second and third protrusions 9 and 10, and the joint body 1 and the latch ring 2 are removably locked.

The lock ring 16 is approximately a perfect circle and has a rectangular cross section, and its outer diameter is smaller than the diameter of the through hole in the latch ring 2 facing the joint body 1 side and larger than the diameter of the through hole on the opposite side. It is also larger than the inner diameter of the stop ring 17 when it is installed. The inner diameter of the lock ring 16 is smaller than the diameter of the expanded portion of the synthetic resin tube. When the stop ring 17 is in a free state, the abutment widens, and when the abutment is closed with the stop ring pliers, the stop ring 17 is attached to the groove 15 of the latch ring 2 and the lock ring 16 is attached.
This prevents the latch ring 2 from coming off the groove 15.
The lock ring 16 is the expanded synthetic resin pipe 3.
It is placed in the unexpanded part of the tube. Groove 15 of latch ring 2
After attaching the lock ring 16 and stop ring 17 to the synthetic resin tube 3, the latch ring 2 is inserted into the synthetic resin tube 3, and then the core 13 is attached to the inner surface of the end of the synthetic resin tube 3.
is inserted, and the synthetic resin pipe 3 is inserted into the joint body 1, and the synthetic resin pipe 3 and the joint body 1 are brought into a watertight relationship by the packing 5. Next, the latch ring 2 is rotated while being pushed in the direction of the joint body 1, the hook 11 is engaged with the hook engaging groove 7, and the latch ring 2 is returned.

In the other joint, there is an abutment 21 defined by a semicircular slit 27 in the end surface 20 of the joint body 2 similar to the above, and tightening means 22, 23 for closing the abutment 21, such as bolts. and a synthetic resin tube 3 whose diameter is reduced by tightening with a nut and whose end is expanded by a core 13.
It has a structure in which an annular tube gripping member 19 that grips the unexpanded tube portion of the tube is integrally connected.

By tightening the abutment portion 21 with bolts 22, nuts 23, etc., the unexpanded portion of the synthetic resin tube 3, which has been reduced in diameter and expanded at the end by the core 13, such as the step 14, is gripped. The inner diameter of the annular tube gripping member 19 when tightened with bolts and nuts is smaller than the diameter of the expanded portion of the synthetic resin tube 3. When rotating and tightening nut 23, tighten bolt 2.
A rib 26 is provided to prevent rotation of the two.

The material of the tube gripping member 19 is preferably an aluminum alloy or the like, which is lightweight, has corrosion resistance, elasticity, and the like. Body end face 20
In order to prevent twisting when the abutment 21 is closed, ribs 24 and 25 are provided on the protrusion from the abutment 21 for reinforcement. The synthetic resin tube 3 is expanded to form a step 14 by press-fitting a core 13 having an outer diameter larger than the inner diameter of the synthetic resin tube 3 into the inner surface of the end portion of the synthetic resin tube 3. Insert the end of the expanded synthetic resin tube 3 into the joint body 1 through the through hole of the annular tube gripping member 19 with the abutment 21 open, and tighten the abutment 21 with the bolt 22 and nut 23 to complete the annular tube. The gripping member 19 is attached to the unexpanded portion of the synthetic resin tube 3, for example, at the step 1.
Fixed at 4.

When water pressure acts on the joint structure of the synthetic resin tubes assembled in this way, the synthetic resin tube 3 is moved in the pulling direction.

At one joint, the operation is as follows.

The lock ring 16 is a step 14 of the synthetic resin pipe 3.
It bites into and improves the resistance to pull-out. Furthermore, when the synthetic resin pipe 3 expands, there is a play 18 between the joint body 1 and the latch ring 2, so that movement of the synthetic resin pipe 3 into the joint body 2 can be accommodated. In addition, when releasing the water pressure and disassembling the assembly, in conventional joints, the latch ring, lock ring, and synthetic resin pipe are firmly fixed, so as the latch ring rotates, the synthetic resin pipe also rotates, and the synthetic resin pipe rotates as the latch ring rotates. Co-rotation may occur in which the other joint of the resin pipe also comes off, but in the joint of the present invention, since there is play 18, the latch ring 3 and lock ring 16 are easily separated, and such co-rotation does not occur.

At the other joint, the operation is as follows.

The edge portion of the annular tube gripping member 19 on the end surface side of the joint body 2 bites into the step 14 of the synthetic resin tube 3 to improve the pullout resistance. Furthermore, when the synthetic resin tube 3 expands, the movement of the synthetic resin tube 3 into the interior of the joint body can be accommodated because there is a play 18 between the joint body 1 and the latch ring 2 at one of the joints. In addition, when releasing the water pressure and disassembling the assembly, in conventional joints, the latch ring, lock ring, and synthetic resin pipe are firmly fixed, so as the latch ring rotates, the synthetic resin pipe also rotates, and the synthetic resin pipe rotates as the latch ring rotates. Co-rotation may occur in which the other joint of the manufactured pipe also comes off, but with the joint structure of the present invention, the synthetic resin pipe 3 can be easily removed from the joint body 1 by removing the bolts and nuts, and co-rotation can occur. does not occur.

(Effects) The joint structure of the synthetic resin pipes of this invention makes piping work very easy, and it can cope with the expansion and contraction of the synthetic resin pipes due to differences in temperature and temperature, and also prevents synergism. Never. In addition, the number of parts is reduced and the cost is reduced.

[Brief explanation of the drawing]

The figure shows an embodiment of the present invention. 1st
The figure is a partial side sectional view taken along the line X-X in Figure 2, Figure 2 is a plan view of the annular tube gripping member side having the abutment, and Figure 3
The figure is a schematic view of the hook engaging groove, and FIG. 4 is a perspective view of the joint body. In the figure; 1... joint body, 2... latch ring, 3...
...Synthetic resin pipe, 4...Annular groove of the joint body, 5...
...Packskin, 6...End peripheral wall surface of joint body, 7
...Hook engaging groove portion, 8...First convex portion, 9...
Second protrusion, 10...Third protrusion, 11...Hook, 13...Core, 14...Step, 15...Inner peripheral groove of latch ring, 16...Lock ring, 17...
Stop ring, 18... play, 19... annular tube gripping member, 20... end face of joint body, 21...
Joint portion, 22, 23... tightening means (bolts, nuts, etc.).

Claims (1)

[Scope of utility model registration request] One joint part connects the gasket 5, which is in watertight contact with the outer circumferential surface of the end of the synthetic resin pipe 3, to the annular groove 4 on the inner circumference of the end.
A hook engaging groove portion 7 is provided inside and is provided on the outer peripheral wall surface 6 of the end portion.
a core 13 for expanding the end of the synthetic resin tube 3; and a core 13 having an inner diameter smaller than the outer diameter of the expanded synthetic resin tube 3, and an unexpanded tube of the synthetic resin tube 3. Lock ring 1 arranged in the part
6, and has an inner peripheral groove 15 for accommodating the joint body 1.
a latch ring 2 having a hook 11 that removably engages with the hook engagement groove 7 of the latch ring 2; The packing 5 has a mold stop ring 17, and the other connecting portion is in watertight contact with the outer circumferential surface of the end of the synthetic resin pipe 3.
In the end face 20 portion of the joint body 1, which is provided in the annular groove 4 on the inner circumference of the end, one abutment part 21 and the abutment part 21 are provided.
An annular ring that grips the unexpanded portion of the synthetic resin tube 3 whose diameter has been reduced by tightening with the tightening means 22 and 23 and whose end has been expanded by the core 13. A joint structure for synthetic resin tubes, characterized in that a gripping member 19 is integrally joined.