JP2864183B2 - Joint - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint for a tube of piping used for water supply and hot water supply, and more particularly, a stainless steel tube having a nominal diameter of about 8 to 22 mm using an O-ring having weather resistance. Related to fittings.

[0002]

2. Description of the Related Art Lead, copper, steel and the like have been used as piping materials for hot water supply or water supply piping of building equipment. Since these pipe materials are easily corroded, the service life of the pipes is short, and the water quality is deteriorated, so that the pipes are not suitable as pipes for supplying drinking water. Stainless steel tubes have been proposed to solve such problems as corrosion resistance of lead tubes and the like.

[0003] Piping such as a stainless steel tube has the advantages of excellent durability and not deteriorating water quality,
Since it is flexible, it also has an advantage that it can be freely piped under the floor or the like without a joint. Such a stainless steel tube and a water heater or a faucet are joined by welding (for example, butt welding type, flange welding type, housing type) or mechanical joining (for example, tightening type, cap nut tightening type, pipe expansion cap nut type). ).

In the case of mechanical joining, the joint at the joint between the stainless steel tube and the faucet is a brass cast product regardless of which method is employed. An acid copper sleeve is used.

[0005]

However, since brass and phosphorous deoxidized copper have high thermal conductivity and expansion coefficient, when they are used for piping joints for hot water, water leakage due to expansion tends to occur. Having. Further, there is a problem that frequent replacement is required because the packing made of synthetic rubber is inferior in corrosion resistance and heat resistance.

On the other hand, it has been proposed to form a joint with a stainless steel material having excellent corrosion resistance. However, in this case as well, water leakage at the joint becomes a problem. Further, such a joint is required to have a pressure resistance to withstand a pressure of about 17.5 kg / cm ² . In view of the above problems, the present invention has no occurrence of water leakage,
Further, an object of the present invention is to provide a joint for a stainless steel tube piping which has excellent corrosion resistance, heat resistance, pressure resistance, a long durable life, and has a simple structure and can be easily joined to a stainless steel tube.

[0007]

To achieve the above object, the present invention provides a bore portion through which a small-diameter stainless steel tube to be connected can be inserted, a female screw portion formed at the other end, a bore portion and a female screw portion. And a connector internally formed with an annular inclined surface for receiving a flare portion of the tube formed between the connector and a male screw portion having a stepped portion at an inner end and being screwed to an internal thread portion of the connector on an outer peripheral surface. And a joint body having: O, which is fitted to the step of the joint body, and presses against the surface of the step and the flare portion of the tube when the joint body and the connecting member are tightened.
Providing a joint comprising a ring;

[0008]

According to the present invention having the above-described structure, O-
When the joint body fitted with the ring and the connector are tightened together, the O-ring is pressed between the joint body and the connector. That is, the O-ring is pressed against the stepped portion of the joint body by the flare surface of the tube disposed on the inclined surface formed inside the connecting tool, and the O-ring is connected to the flare portion of the connected tube at one point. Further, the space between the joint body and the tube is sealed while contacting the step portion of the joint body at two points.

[0009]

FIG. 1 is a block diagram showing a first embodiment of the present invention.
This will be described in detail with reference to FIG. FIG. 1 is a partial cross-sectional side view showing the joint of the first embodiment in an assembled state. The joint 1 of this embodiment includes a joint main body 2 having a through bore, a hexagonal cap nut (connector) 3, and an O-ring 4. The joint body 2 and the cap nut 3 are desirably formed of stainless steel such as SUS304 steel.

The cap nut 3 is formed with a bore 32 for receiving the small-diameter stainless steel tube 5, and a female screw 31 is formed on the inner periphery of one end of the cap nut 3. Inside the cap nut 32, for example, 45
An annular inclined surface 33 is formed to receive the flared portion 51 of the stainless steel tube 5. The joint body 2 has a hexagonal outer peripheral middle portion, and male screw portions 21 and 22 are formed at both outer peripheral end portions, respectively. Further, the inner end surface of the joint body 2 adjacent to the one male screw portion 21 of the joint body 2 is tapered, and an annular step 23 is formed at the inner end of the joint body following this taper. . The cylindrical surface 32b of the step portion 23 has a diameter substantially the same as the inner diameter of a sealing O-ring 4 which is a ring-shaped member having a substantially circular cross section, which will be described later. The width of the cylindrical surface 23b of the step portion 23 is substantially the same as or slightly larger than the diameter of the cross section of the O-ring 4. On the other hand, this step 2
The rising surface or shoulder 23a of 3 is approximately the same as or slightly larger than the diameter of the cross section of the O-ring 4. As a result, the step portion 23 is connected to an O-ring 4 described later.
Is large enough to place the The O-ring 4 is made of a material having relatively high rigidity such as polytetrafluoroethylene and having excellent weather resistance. The shape and dimensions of the O-ring 4 are appropriately determined according to the usage conditions.

A male thread 21 on one end of the joint body 2 and a female thread 31 on the cap nut 3 are screwed together, and the male thread 22 on the other end is a faucet (not shown) to which the stainless steel tube 5 is to be connected. ) Can be screwed together. When the joint body 2 and the cap nut 3 are tightened together, the O-ring 4 placed on the step 23 is located on the inclined surface 33 of the cap nut 3 at a point A as shown in FIG. It comes into contact with the flare 51 of the stainless steel tube 5. At this time, the O-ring 4 and the cylindrical surface 23b and the shoulder 23a of the step portion 23 of the joint main body 2 abut at points B and C as shown in FIG.
A perfect seal is formed between the joint body 2 and the stainless steel tube 5 by the ring 4, and the stainless steel tube can be connected to the joint 1. At this time, the flare 51
Is inclined and presses the O-ring 4 fitted on the step portion 23, so that the O-ring 4 is pressed against the points B and C with substantially uniform force.

Next, a joint 1 'according to another embodiment of the present invention will be described with reference to FIG. Joint 1 'of the second embodiment
The joint has basically the same configuration as the joint 1 of the first embodiment, and includes a joint main body 2 ′, a cap nut 3, and an O-ring 4 for sealing. FIG. 3 shows a state in which the joint body 2 ′ and the cap nut 3 are fastened to each other, and the O-ring 4 fitted on the step portion of the joint body 2 ′ is pressed against the flare portion of the stainless tube. The difference between the joint 1 'of the second embodiment and the joint 1 is that the other end of the joint main body 2' (the end opposite to the end to which the cap nut 3 is connected) is not a male thread but a female thread. 22 'is formed. The joint 2 'of the second embodiment is used when a faucet or the like (not shown) to which the stainless steel tube 5 is connected has a male screw portion at the connection portion.

The above embodiment is merely an example and does not limit the present invention in any way. The present invention is not limited to the various technical matters described in the claims but may be variously modified.
Deformation becomes possible.

[0014]

According to the present invention, which has been described in detail according to the above embodiment, when the joint body and the cap nut (connecting tool) are tightened together, the O-ring connects the step portion of the joint body and the flare portion of the tube. Since the O-ring part is sufficiently sealed between the tube and the joint body, the joint exhibits a necessary and sufficient pressure resistance performance because the O-ring part is sufficiently pressed and sandwiched in a three-point contact state therebetween.
Further, since the sealing O-ring disposed between the joint body and the cap nut (connecting tool) is formed of a material having excellent weather resistance, water leakage due to the corrosion of the O-ring occurs. And the durable life of the joint is extended.

Further, since the O-ring has high heat resistance, the joint of the present invention can be applied to a joint of a piping tube for hot water supply. Can be prevented. Further, since the joint body and the connecting member have a simple structure, and a standard O-ring can be used for sealing, the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a side view showing a cross section of a part of a joint according to a first embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of an O-ring portion of the joint according to the first embodiment in a state where a joint main body and a connector are fastened to each other.

FIG. 3 is a side view showing a part of a joint according to a second embodiment of the present invention in section.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Joint 2 Joint main body 3 Cap nut (connector) 4 O-ring 5 Stainless steel tube 21 Male thread 22 Male thread 23 Step 22 'Female thread 31 Female thread 32 Bore 33 Inclined surface 51 Flare

Claims (1)

(57) [Claims] 1. A bore portion provided at one end side and through which a stainless steel tube for water supply or hot water supply to be connected can be inserted,
A female screw portion provided on the other end side and having an inner diameter larger than the bore portion and having an internal thread provided on an inner periphery thereof; one end of the stainless steel tube provided between the bore portion and the female screw portion; A connector having an annular inclined surface that comes into contact with a flare portion formed at the end; a male screw having a step at the tip, and further having a male screw formed on the outer peripheral surface to be screwed with the female screw. A joint body provided with a portion, and a male screw of the joint body which is fitted to a step portion of the joint body and which comes into contact with a surface of the step portion and the annular inclined surface when a male screw of the coupling member is screwed into a female screw of the coupling tool. A stainless steel tube joint for water supply or hot water supply, comprising: an O-ring that presses against the inner surface of the flare portion of the stainless steel tube in contact therewith.