JPH0547346Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to improvements in pipe joints used to connect pipes for transferring fluids such as hot water and chemicals that accelerate the deterioration of packing.

[Conventional technology]

As shown in Figure 3, in conventional pipe joints, the fitting, washer, chuck ring, and bag nut are attached to one end of the fitting body connected to the main pipe (A) in a loosened state, and each member is penetrated. After inserting a connecting pipe C such as a copper pipe into the joint body A, tightening the cap nut, the chuck ring digs into the surface of the connecting pipe to prevent the connecting pipe from coming off, and also prevents the inner surface of the fitting from coming off. is crimped onto the surface of the connecting tube to prevent leakage of internal fluid.

[The problem that the idea attempts to solve]

However, when a pipe joint with the above-mentioned structure is used to connect a pipe for transferring fluids such as hot water or chemicals, the above-mentioned pipe fitting is always exposed to the fluid that enters from the gap between the joint body B and the connecting pipe C. Exposure hastened its deterioration or aging.

Furthermore, because the conventional bag nut has an internal thread cut out over almost the entire inner peripheral surface, the amount of deformation of the nut compressed by the tightening of the bag nut is caused by the amount of deformation in the concave part of the internal thread. In addition to reducing the surface pressure on the circumferential surface of the connecting pipe C by inserting it,
The above-mentioned jacket was damaged or torn by the inner screw of the bag nut.

In addition, if the connecting pipe is tilted for some reason after the connecting pipe C has been connected, the seal, which performs the sealing function by surface contact, may lose its crimp force on the opposite side. There was a problem with the leakage tendency.

[Means to solve the problem]

Therefore, in order to solve the above-mentioned problems, the present invention provides a pipe joint in which a connecting pipe that is inserted into a joint body is connected to the joint body using a packing, a washer, a chuck ring, and a cap nut in a manner that prevents the connecting pipe from coming off and allows sealing. A step is provided on the inner periphery of the opening on the connecting pipe side of the joint body, and an O-ring and washer are fitted to the step. We used a method of making the surface without threads.

[Function] The pipe fitting of the present invention uses the O-ring to seal fluid that enters the gap between the fitting body and the connecting pipe and comes into contact with the packing, and also uses the line contact function of the O-ring to prevent fluid from inclining the connecting pipe. It has the effect of preventing deterioration of sealing performance.

〔Example〕

Hereinafter, the structure of the present invention will be described in more detail based on the embodiment shown in the drawings. Reference numeral 1 denotes a joint body with external threads 1a cut on the outer periphery of both ends, and the installation pipe P made of copper pipe or the like. There is a step 1 on the inner circumference of the opening on the insertion side.
b and 1c are arranged in a ring, and a synthetic rubber O-ring 2 and a washer 3 having excellent heat resistance and chemical resistance are fitted into the stepped portions. Further, 4 is a packing that comes into contact with the end face of the joint body 1 and the washer 3, 5 is a washer for holding down the packing, 6 is a chuck ring having an inclined surface on one side, and 7 is a cap nut. As shown, its inner circumferential surface is made approximately the same diameter as the outer circumferential surface of the packing 4, and an inner thread 7a is cut only on the inner circumference of the opening end to engage with the outer thread 1a of the joint body 1. , while the intermediate part between the inner thread and the inner deep surface 7c is a smooth unthreaded surface 7b, the end surface of the through hole for insertion of the connecting pipe P is inclined so as to be compatible with the inclined surface of the chuck ring 6. be.

Therefore, in the proposed pipe joint, first, one end side of the joint body 1 is connected to the main pipe P', and the inner circumferential stepped portions 1b, 1c on the other end side are
After fitting the O-ring 2 and washer 3 to the joint body 1, a packing 4, a washer 5, and a chuck ring 6 are installed between the tip of the joint body 1 and a cap nut 7 loosely screwed onto the external thread 1a. After that, insert the connecting pipe P into the joint body 1 and tighten the cap nut 7.
The packing 4 is pushed by the chuck ring 6 and slides into contact with and moves forward along the non-threaded surface 7b of the cap nut 7,
The chuck ring is pressed between the joint body 1 and the washer 3.

At this time, the chuck ring 6 bites into the surface of the connecting pipe P to prevent it from coming off, as in the conventional case, but since the outer peripheral surface of the packing 4 is pressed against the smooth non-threaded surface 7b, The inner circumferential surface of the packing is strongly pressed against the surface of the connecting pipe P in an attempt to reduce its diameter, and at the same time, the O-ring 2 fitted inside the stepped portion 1b of the joint body is also pressed against the stepped surface and the washer. 3, the three sides are in contact with each other, so that there is strong line contact with the surface of the connecting pipe P, effectively sealing that part.

[Effect of idea]

As mentioned above, the pipe joint of the present invention double-seals the joint body and the connecting pipe with an O-ring fitted into the stepped part of the main body and a tightening type packing. Especially when used to connect fluid transfer pipes such as hot water or chemicals.
Fluid entering from the gap between the connecting pipe and the fitting body is blocked before the packing by the O-ring, which has excellent heat and chemical resistance, and the packing is not directly exposed to the fluid, preventing its deterioration. Or the progress of aging can be prevented. Therefore, a high sealing effect can be maintained for a long period of time.

Also, due to some reason, the above connecting pipe may become tilted.
Even if the contact force with the packing partially decreases, the O-ring that is in line contact with the connecting pipe can reliably prevent fluid leakage.

In addition, in the proposed pipe joint, the middle part of the cap nut is a non-threaded surface that can slide into contact with the outer circumferential surface of the packing, so the inner circumferential surface of the packing is strongly crimped to the surface of the connecting pipe, creating a seal. In addition to further improving functionality, the packing is not damaged or torn by the internal threads of the cap nut, unlike conventional products.
It exhibits excellent effects.

[Brief explanation of the drawing]

FIG. 1 is a partially cut-away side view of the proposed pipe joint, FIG. 2 is an enlarged sectional view of the main part thereof, and FIG. 3 is a partially cut-away side view of a conventional pipe joint. In the figure, 1... joint body, 1b, 1c... stepped portion, 2... O-ring, 3... washer, 4... packing, 5... washer, 6... chuck ring, 7...
Cap nut, 7a...Inner thread, 7b...Unthreaded surface.

Claims (1)

[Scope of utility model registration request] In a pipe joint in which a connecting pipe to be inserted into the joint body is connected to the joint body using a packing, a washer, a chuck ring, and a cap nut in a manner that prevents it from coming off and allows a seal, a step is formed on the inner periphery of the opening on the side of the connecting pipe of the joint body 1. The O-ring 2 and the washer 3 are fitted into the step portions 1b and 1c, and the middle portion of the inner periphery of the cap nut 7 is formed with a non-threaded surface 7b having approximately the same diameter as the outer periphery of the packing 4. A pipe joint characterized by: