JPH0942549A - Seal member for tube fitting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seal member for a slip-on type tube fitting in which the resistance in the compression condition between a spigot and an acceptor is not large, and the reduction of the compression ratio is not generated even when the joint is bent. SOLUTION: While seal member is composed of a circular body made of a rubber, it has a heal part 31 and a valve part 32. On the outer periphery of the border between the heal part 31 and the valve part 32, a thin wall groove 36 is provided. A parallel part 35 with the same thickness along the axial direction is provided to the valve part 32.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a sealing material for pipe joints.

[0002]

2. Description of the Related Art As one type of pipe joint, there is a slip-on type pipe joint. This slip-on type pipe joint can be installed by simply installing a sealing material on the inner circumference of the receiving port formed on one pipe and inserting the insertion port formed on the other pipe into this receiving port. The sealing material is compressed between the insertion port and the insertion port to complete the joining of the joint.

As a sealing material used for such a slip-on type pipe joint, a rubber material having an annular shape having a cross-sectional shape shown in FIG. 4 is often used. The seal material 1 shown in FIG. 4 is formed to have a heel portion 2 for mounting on the inner periphery of the receiving opening and a valve portion 3 compressed between the receiving opening insertion portions. Valve part 3
Has a semicircular cross-sectional shape, and the inner periphery of the valve portion 3 and the heel portion 2 are connected by a tapered surface 4.

[0004]

However, such a conventional sealing material has a problem in that the resistance at the time of compression between the receiving and inserting ports is large, and that the work of joining the pipe joints is troublesome. Further, since the valve portion 3 has only a semicircular cross-sectional shape, there is a problem that when the joint bends, the compression rate thereof may decrease and the sealing performance may deteriorate.

Therefore, the present invention solves such a problem, and the resistance at the time of compression between the receiving and inserting ports is not so large,
Moreover, it is an object of the present invention to prevent the compression rate from decreasing even when the joint is bent.

[0006]

To achieve this object, a sealing material of the present invention is composed of a rubber annular body and has a heel portion and a valve portion. There is a thinned groove on the outer periphery of the boundary portion between the valve and the valve portion, and the valve portion has a parallel portion having a uniform thickness along the axial direction.

With such a structure, since the outer peripheral portion of the boundary portion between the heel portion and the valve portion is provided with the metal thinning groove, the overall rigidity is lowered, and therefore compression is performed between the receiving and inserting openings. It will be easy. In addition, since the parallel part with uniform thickness is formed along the axial direction on the valve part, even if the joint bends, this parallel part will surely adhere to the receiving port and the insertion port. Therefore, it is possible to prevent the compression rate from being lowered when the bending occurs.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 shows an example of a slip-on type pipe joint equipped with a seal material according to the present invention. That is, the receiving port 12 is formed at the end of one pipe 11 that is joined to each other, and the insertion end that is inserted into the receiving port 12 is provided at the end of the other pipe 13 that is joined to this pipe 11. A mouth 14 is formed. A ring-shaped sealing material accommodating groove 15 is formed on the inner periphery of the receiving opening 12, and the sealing material accommodating groove 15 is a deep groove portion 16 having a rectangular cross section formed on the receiving opening side, and on the inner side of the receiving opening. And a pressure contact portion 17 formed in the tube axis direction. The seal material accommodating groove 15 accommodates the seal material 18 according to the present invention.
It is compressed between the inner peripheral surface and the outer peripheral surface of the insertion opening 14.

Receiving port on the inner side of the sealing material accommodating groove 15
A lock ring receiving groove 21 is formed on the inner circumference of 12,
The lock ring 22 is housed in the lock ring housing groove 21 and is divided in the circumferential direction. Between the outer peripheral side of the lock ring 22 and the inner peripheral side of the lock ring housing groove 21, a holding rubber ring 23 for holding the lock ring 22 in a centered state is arranged. A protrusion 24 is formed on the outer periphery of the tip of the insertion slot 14 so that the lock ring 22 can be engaged with the lock ring 22 from the rear side. Also, on the outer periphery of the insertion port 14 on the tip side of the protrusion 24,
A tapered surface 25 is formed. On the inner peripheral surface of the receiving port 12 on the far side from the lock ring accommodation groove 17, a taper surface 26 that spreads deep
Are formed.

The seal member 18 is made of a rubber annular body and has a sectional structure shown in FIG. 1 when it is not compressed between the receiving openings, that is, before being attached to the receiving openings. Is formed.

The seal member 18 includes a heel portion 31 and a valve portion 32.
And are integrally formed by baking or the like, the heel portion 31 is made of a hard rubber material, and the valve portion 32 is made of a soft rubber material. Specifically, the heel portion 31
Has a hardness of about 80, and the valve portion 32 has a hardness of about 50. Reference numeral 33 is an integrated joint surface between the heel portion 31 and the valve portion 32. The heel portion 31 is a sealing material accommodating groove of the receptacle 12.
It is formed so as to protrude outward in the radial direction so as to be mounted in the deep groove portion 16 of 15. Further, the valve portion 32 is formed with a thickness that allows compression between the pressure contact portion 17 of the seal material accommodating groove 15 and the outer periphery of the insertion opening 14. The valve portion 32 includes a semicircular portion 34 having a semicircular cross section formed on the tip side, and the semicircular portion 34.
Subsequent to 34, there is a parallel portion 35 formed so as to have a uniform thickness along the axial direction. B is the thickness of the valve portion 32, that is, the diameter of the semicircular portion, G is the length of the parallel portion 25 along the axial direction, and E is the length of the sealing material 18 along the axial direction. is there.

A thin wall groove 36 is formed on the outer periphery of the sealing material 18 at the boundary between the heel portion 31 and the valve portion 32. The thinned groove 36 is formed to have a semicircular cross section, and R is the radius of the semicircular portion. Between the inner circumference of the heel portion 31 and the inner circumference of the valve portion 32, a tapered surface 37 whose inner diameter gradually decreases from the heel portion 31 toward the valve portion 32 is formed. θ is a taper angle of the tapered surface 37, that is, an angle formed by the axial center of the seal material 18 and the tapered surface 37.

Next, details of dimensions of each part will be described.
First, the radius R of the thin wall groove 36 is compared with the diameter B of the valve portion 32.
It is necessary to form it in a size range of 0.10 B or more and 0.15 B or less. When this dimension exceeds 0.15B, the sealing material 18 is excessively thinned at the portion where the thinning groove 36 is formed, and the engagement between the heel portion 31 and the deep groove portion 16 of the receiving port 12 becomes weak. Therefore, as shown in FIG. 3, when the insertion opening 14 is inserted into the receiving opening 12, the sealing material 18 is disengaged from the predetermined position due to the pushing force from the insertion opening 14 to the rear side of the receiving opening 12. There is a risk that As a result, the target sealing performance may not be achieved. On the other hand, if it is less than 0.10 B, the substantial effect of forming the wall thickness reducing groove 36 is lost, and when the insertion port 14 is inserted into the receiving port 12 and the sealing material 18 is compressed as shown in FIG. The resistance cannot be reduced, and a large force is required to join the joints. Also, the sealing material 18
A large force is required even when the product is narrowed down when it is mounted in the accommodation groove 15, and the mountability thereof deteriorates.

The length G of the parallel portion 25 is equal to the length E of the sealing material 18.
On the other hand, it is necessary to form in the range of 0.3E or more and 0.8E or less. If this dimension exceeds 0.8E, the sealing material
When 18 is compressed, the resistance increases, and a large force is required to join the joints. If it is less than 0.3E, the parallel portion 25 is too short, and the substantial effect of providing the parallel portion 25, that is, the predetermined sealing property when the joint is bent cannot be obtained. That is, the target sealing property and proper joining workability when the joint is bent can be obtained for the first time within the above range.

The taper angle θ of the taper surface 37 is preferably set to 30 degrees, and the taper angle θ can be made narrower than the conventional taper angle of 23 degrees, whereby the total length E of the sealing material 18 can be shortened.

According to this structure, since the thin wall groove 36 is formed, the resistance at the time of inserting the insertion opening 14 into the receiving opening 12 and compressing the sealing material 18 can be reduced, and further, the sealing material 18 can be squeezed. Therefore, the work can be easily performed even when it is installed in the accommodation groove 15 in the receiving port 12. By forming the parallel part 35,
Even if the joint bends so that the insertion port 14 bends in the tapered surface 26 of the 12, the parallel portion 35 surely adheres to the bottom surface of the receiving groove 15 on the receiving port 12 side and the outer surface of the insertion port 14. This means that the deterioration of the sealing property due to the decrease of the compression rate when the bending occurs is prevented. Further, since the sealing member 18 is not made to have a uniform hardness as a whole and the heel portion 31 is made hard and the valve portion 32 is made soft, the deep groove portion 16 of the accommodation groove 15 and the heel portion are formed.
Since the engagement with 31 can be secured, it is possible to prevent the displacement of the sealing material 18 at the time of joining the joint and to expect a reliable sealing performance by the valve portion 32.

[0017]

As described above, according to the present invention, a thin wall groove is provided on the outer periphery of the boundary between the heel portion and the valve portion, and the valve portion has a uniform thickness along the axial direction. Since it has a portion, it is possible to reduce the rigidity of the entire sealing material due to the groove for reducing the wall thickness, and therefore, it is possible to easily mount the sealing material in the receiving opening, and it is easy to perform compression between the receiving opening and Since it has a parallel part, even if the joint bends, this parallel part can be surely brought into close contact with the receiving port and the insertion port, and it is possible to prevent the compression rate from decreasing when this bending occurs. And reliable sealing performance can be maintained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a sealing material for pipe joints according to the present invention.

FIG. 2 is a cross-sectional view of an example of a pipe joint using the seal material of FIG.

FIG. 3 is a diagram illustrating a joining operation of the pipe joint of FIG.

FIG. 4 is a cross-sectional view of an example of a conventional sealing material for pipe joints.

[Explanation of symbols]

 31 Heel part 32 Valve part 35 Parallel part 36 Thin part

Claims (1)

[Claims] 1. A rubber annular body, which has a heel portion and a valve portion, and a wall-thinning groove at the outer periphery of the boundary portion between the heel portion and the valve portion, ,
A sealing material for pipe joints, which has a parallel portion having a uniform thickness along the axial direction.