JPH0133915Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention is used for connection with flexible pipe bodies such as tubes and hoses used for transferring various fluid substances such as air and liquids. In particular, the present invention relates to a pipe joint that can securely seal even when a soft tube that is easily permanently deformed is connected.

[Conventional technology]

For example, soft polyvinyl chloride, polyurethane,
In equipment using tubes made of soft polymeric materials such as silicone rubber, when flowing low-temperature liquids or using them in a low-temperature atmosphere, these tubes harden and lose their elasticity significantly, resulting in some problems in use. This causes problems. Among them,
At the connection part with the pipe fitting, the pipe body is deformed to match the shape of the connection point and cannot return to its original state due to a decrease in elasticity.As a result, the tightness between the pipe body and the pipe fitting at the sealing part is reduced. This caused problems in that not only did the fluid leak from the connection point, but the tube also became easily dislodged. In this case, even if the tube is tightened strongly in advance, it is not very effective in reducing the elasticity of the tube because it hardens in a compressed shape, and it is difficult to completely prevent leakage with conventional pipe fittings. Therefore, it has been desired to develop a pipe joint that has good sealing performance and tensile strength, especially when used at low temperatures.

[Problem that the invention attempts to solve]

In view of the above-mentioned problems of the conventional technology, this idea connects tubes made of soft polymer materials,
To provide a pipe joint that does not allow fluid to leak from a connection point and prevent a pipe body from coming off even when low-temperature fluid is flowed.

[Means for solving problems]

This invention was made in order to solve the problems of the prior art, and therefore, according to this invention, a male threaded part, an annular groove, a pipe hooking part, and an annular convex part are provided on the outer peripheral surface. and a tube inserting portion that fits inside the tube, the fitting body is fitted in an annular groove of the joint body and resiliently contacts the inner circumferential surface of the tube for sealing. a seal ring to be held; and a pressing portion that is screwed into a male threaded portion provided on the outer circumferential surface of the joint body and presses the inner circumferential surface of the tube against the seal ring in contact with the outer circumferential surface of the tube end; and a tightening nut having a clamping pressure part that clamps and locks the pipe joint with the annular convex part.

[Effect]

According to this invention, as described above, a tapered annular convex portion whose diameter increases in the tube insertion direction is provided on the outer circumferential surface, and the peripheral edge of the annular convex portion on the tube end side is used as a hooking portion, Furthermore, there is a joint body with a pipe insertion part at the end, which is provided with an annular groove on the end side of the pipe body from this hook part, and a fitting body that is ringed in the annular groove of this joint body and elastically attached to the inner circumferential surface of the pipe body. a seal ring that is in contact with the joint body, and a clamping force that is screwed into the external thread formed on the outer peripheral surface of the joint body, faces the annular convex part of the joint body at a position close to it, and clamps and locks the pipe body with the annular convex part. and a tightening nut having a pressing part that appropriately presses the tube body against the seal ring from the outer peripheral surface, so that the tube body inserted into the tube body insertion portion can be tightened By tightening the nut, the clamping part of the tightening nut and the annular convex part of the joint body are clamped and locked from the inner and outer surfaces.

In this case, in addition to the tubular body being clamped and locked between the annular convex portion and the clamping pressure portion, the locking portion provided on the annular convex portion engages with the inner circumferential surface of the tube to apply clamping pressure to the tubular body. Since the pipe is latched without any force, even if the pipe body creeps and remains deformed (or rather, if creep occurs), it will be securely latched.

Further, sealing is not only performed temporarily between the annular convex portion and the clamping pressure portion, but also permanently between the seal ring fitted in the annular groove of the joint body and the pressing portion of the tightening nut. It will be done. At that time, the seal ring absorbs and stores the pressure in the inner radial direction of the tube body due to the pressing part of the tightening nut, thereby supporting it softly and preventing compressive deformation of the tube body, and also moves the tube body toward the inner circumferential surface. As a result, even if the thickness of the tube body changes, the tube body is appropriately compressed from the inner and outer surfaces, thereby preventing the elasticity of the tube from decreasing, especially when connecting a soft tube and using it at low temperatures. Even when the tube is in contact with the seal ring, there is no creep, so the closeness between the tube and the seal ring is maintained well and stably.
No fluid leakage occurs.

〔Example〕

FIG. 1 is a partial longitudinal sectional side view showing an embodiment of a pipe joint 1 according to this invention. In the embodiment, the joint body 10 has a tapered annular convex portion 11 at one end thereof, the diameter of which increases in the insertion direction of the tube body 2 from the tip.
and an annular groove 12 formed on the end side of the tube body 2 following the annular convex portion 11.
Further, a male threaded portion 14 is provided on the outer circumferential surface following the tube insertion portion 13. In this case, the peripheral edge of the annular convex portion 11 on the tube end side serves as a hook portion 15 that engages with the inner circumferential surface of the tube 2. Further, a seal ring 30 made of an elastic material is fitted around the annular groove 12 of the joint body 10. on the other hand,
The tightening nut 20 has a female threaded part 21 that is screwed into the male threaded part 14 of the joint body 10, and following this female threaded part 21, the pipe body 2 fitted into the pipe body insertion part 13 of the joint body 10 is attached to the outer periphery. It has a pressing part 22 that presses the seal ring 30 from the surface, and is further adjacent to the tapered annular convex part 11 of the joint main body 10 following this pressing part 22, and is connected to the annular convex part 11.
A step 23 facing the tube body 2 is formed, and this step 23 constitutes a clamping pressure portion that clamps the outer surface of the tube body 2 in the thickness direction.

Next, the manner of use of the pipe joint 1 according to this invention will be explained. First, insert the tube 2 into the tightening nut 20, and then fit the tip of the tube 2 into the tube insertion part 13 of the joint body 10 until the tip of the tube 2 comes into contact with the screen surface 16 of the annular groove 12. Push it in. Next, by screwing the tightening nut 20 into the male threaded portion 14 of the joint body 10, the clamping pressure portion 23 of the tightening nut 20 is inserted into the tube body insertion portion 1 of the joint body 10.
The tubular body 2 is clamped between the tapered surface of the annular convex portion 11 formed in the tubular body 3, and the inner and outer surfaces of the tubular body 2 are clamped and locked from the thickness direction by both.

Furthermore, the inserted tube body 2 has a seal ring 3
It is hooked to the peripheral edge of the annular convex portion 11 on the tube end side as a hook portion 15 that protrudes in the radial direction from the outer circumferential surface of the tube.

On the other hand, in addition to the sealing action of the annular convex portion 11 and the clamping pressure portion 23, the sealing of the tube body 2 is performed by the pressure portion 22 of the tightening nut 20 at the portion where the tube body 2 and the seal ring 30 contact each other. It absorbs and stores pressure in the direction of the inner diameter of the tubular body to prevent compressive deformation of the tubular body, and also elastically presses the tubular body 2 from the inner circumferential surface and appropriately pinches the tubular body 2 from the inner and outer surfaces. Therefore, there is no creep in the portion of the tube body 2 in contact with the seal ring 30, and the close contact between the two is always maintained in a reasonably stable manner. Therefore, even when the elasticity of the tube body 2 decreases due to changes in the fluid temperature or ambient temperature, it is possible to seal reliably. In addition, tightening nut 2
The pressing portion 22 of 0 does not necessarily need to protrude from the inner circumferential surface; for example, a straight hole may be formed between the female threaded portion 21 and the clamping portion 23 depending on the material, wall thickness, etc. of the pipe to be connected.

FIG. 2 shows another embodiment of the pipe joint according to this invention, and the illustrated pipe joint 3 is composed of a joint body 40, a tightening nut 50, and a seal ring 60, similar to the embodiment shown in FIG. In this embodiment, the annular convex portion 41 of the joint body 40 has a tapered portion 42 whose diameter increases in the insertion direction of the tube body 2 from the tip.
and a straight part 44 that is provided following the tapered part 42 and is formed to have a smaller diameter than the peripheral edge part 43 (latching part) on the tube end side of the tapered part 42 that engages with the inner circumferential surface of the tube body 2. Further, an annular groove 45 is provided following the straight portion 44. In this case, the seal ring 60 fitted in the annular groove 45 has a larger diameter than the peripheral edge 43 of the tapered portion 42 of the annular convex portion 41 on the tube end side. In addition, the tightening nut 50
Continuing to the female threaded portion 51 that is screwed into the joint body 40, the fitting has a straight hole that acts as a pressing portion 52, and further includes a step that serves as a clamping portion 53.

In this case, the seal ring 6 of the inserted tube 2
Since the outer diameter of the seal ring 60 is larger than the outer diameter of the hooking portion 43 of the annular convex portion 41, the outer diameter of the portion in contact with 0 is larger than that of the portion in contact with the hooking portion 43. When tightening the nut 50, the pressing part 52 of the tightening nut 50
At position 3, there is no catching and smooth tightening can be performed.

Note that it is of course possible to use seal rings with shapes other than those shown in the above embodiments; for example, seal rings of various shapes and materials such as V-seals, soft plastic tubes, cut rubber tubes, etc. can be used. The shape of the annular groove of the joint body in which the seal ring is fitted is as follows:
It may be selected as appropriate depending on the shape of the seal ring, and its position etc. may be changed arbitrarily.

In this way, the pipe joint 1 according to the present invention locks and seals the pipe body with the clamping part of the tightening nut and the annular convex part of the joint body, and also locks and seals the pipe body with the hook part provided on the annular convex part. It is attached to the inner peripheral surface of the tube, and seals by applying appropriate pressure from the inner and outer surfaces without compressing and deforming the tube, so the elasticity of the tube decreases due to temperature changes. Even in this case, there is no major change in the contact state between the tube and the seal ring, and therefore no fluid leakage occurs. Further, since the inserted tube is hooked to the hook of the annular convex portion, it will not come off even if the tube loses its elasticity and remains deformed.

[Effect of idea]

As explained above, according to this invention, the outer circumferential surface of the tube insertion portion has an annular protrusion and an annular groove, and the annular protrusion engages the inner circumferential surface of the tube to hang the tube. a joint body having a hook portion for locking the joint body; a seal ring that is surrounded by an annular groove of the joint body and seals and holds the pipe body by appropriately elastically contacting the inner circumferential surface of the pipe body; and a seal ring that is screwed onto the joint body. and a tightening nut having a pressing part that presses the tubular body from the outer peripheral surface and presses the inner peripheral surface of the tubular body against the seal ring, and a clamping part that clamps and locks the tubular body with the annular convex part. Because of this, there is no creep in the tube body in contact with the seal ring, resulting in excellent sealing properties. Even when the elasticity of the tube is significantly reduced due to use in an atmosphere, there is no major change in the contact state between the seal ring and the tube body, and therefore no fluid leakage occurs.

Furthermore, since the inserted tube is latched to the latching portion of the annular convex portion without applying pressure on the inner peripheral surface, the tube remains deformed due to a decrease in its elasticity due to temperature changes, compression, etc. It will not come off even under certain conditions, making it an extremely reliable pipe joint.

Note that this invention is not limited to the above embodiments, and for example, the shape, position, and number of the annular protrusion and the hooking portion may be changed, or the clamping portion of the tightening nut may be made tapered, or the shape of the pressing portion may be changed. Of course, various changes within the technical idea of this invention, such as changing the position, are possible.

[Brief explanation of the drawing]

FIG. 1 is a partially vertical side view showing one embodiment of a pipe joint according to this invention, and FIG. 2 is a partially vertical side view showing another embodiment. 10, 40... Joint body, 11, 41... Annular convex portion, 12, 45... Annular groove, 13... Pipe body insertion part, 15, 43... Latching part, 20, 50... Tightening nut, 22, 52...Press portion, 23, 53
... Clamping pressure part, 30, 60 ... Seal ring.

Claims (1)

[Scope of utility model registration request] A joint body having a male threaded portion, an annular groove, a tube hooking portion, and a tube insertion portion having an annular convex portion and fitting inside the tube in this order on the outer peripheral surface; A seal ring is installed in the annular groove and elastically contacts the inner circumferential surface of the tube to seal and hold it, and a seal ring is screwed into the external thread provided on the outer circumferential surface of the joint body and is attached to the outer circumferential surface of the end of the tube. A pipe joint comprising a tightening nut having a pressing part that presses the inner circumferential surface of the tube against the seal ring and a clamping part that clamps and locks the tube with the annular convex part.