JPH0211673Y2 - - Google Patents

Description

[Detailed explanation of the idea]

The present invention relates to the development of a threaded joint for hot water supply pipes, which effectively prevents rust from forming at the joint part of the hot water supply pipe that supplies potable hot water with a flexible seal structure, and which does not elute components unsuitable for drinking. Furthermore, such a joint can be easily manufactured, and a watertight structure can be easily and accurately constructed. Requirements for pipe joints used in potable water supply pipes include heat resistance, rust resistance, and drinkability. In other words, since hot water pipes transport hot water at a temperature of 80 to 90°C, the inside of the pipes cannot be allowed to be damaged by the heat and steam, and if rust forms on the inner surfaces of the steel pipes and joints, red water may occur. This results in various harmful effects, and furthermore, it is unacceptable for materials used for hot water supply piping to generate substances harmful to the human body. By the way, among these requirements, rust is the most problematic.For example, in conventional commercial hot water supply joints, as shown in Figs. Although JIS B2301 indicates the use of a socket 14 that is covered with a core 12 and has a lining 13 on the inner surface, rust does not occur on the end surface of the tube 10 using this method. Even if the female threaded portion 15 of the socket 14
As shown in Figure 3, this part is not coated, and this part is exposed to a certain extent, and the metal surface comes into direct contact with water and steam, so rust is unavoidable. be. On the other hand, as shown in FIG. 4, a socket 14 whose inner surface is plated with aluminum is used, and the end of the male thread 11 cut into the tube body 10 and a part of the female thread 15 of the socket 14 are filled with a two-component solution containing aluminum. It is also possible to maintain rust prevention by applying adhesive 17, but since this method uses adhesive 17, it is inferior in workability. There is the hassle of having to adjust the timing each time, and
Ventilation of the construction site must be taken into consideration since toxic gas is generated when the liquid is mixed, and simple application cannot effectively prevent the penetration of vapor, etc., and there are disadvantages such as rusting over time. . The present invention has been devised after consideration to eliminate the disadvantages and shortcomings of the conventional ones as described above, and the specific embodiment thereof is explained as shown in the attached drawings. When connecting the tubes 10, 10, both tubes 10, 1
The socket 1 is equipped with a ring member 2 made of a rubber material harmless to the human body, such as silicone rubber or fluorine rubber, with tube end receiving recesses 3, 3 arranged oppositely between the ends of the socket 1. A resin layer 4 is filled between the ring member 2 and the tube end 10a, and is formed as a compacted filling layer 4a by screwing the tube end 10a into the socket. After injecting a resin 4 which is harmless to the human body between the
The resin layer 4 is screwed into the female screw and tightened.
The purpose is to achieve complete rust prevention by making the tube denser and effectively filling the resin layer in the tube end portion 10a. The socket 1 and the ring member 2 have cross-sectional shapes as shown in Fig. 6, and are manufactured so that the ring member 2 is in close contact with the inner surface of the socket 1. Therefore, the ring member 2 is manufactured for each diameter. Also, socket 1
A ring receiving recess 5 is formed in the ring. After the ring member 2 is installed in the receiving recess 5 as shown in FIG. 7, silicone resin or the like is injected into the gap between the two members 1 and 2 from a resin tube 8 as shown in FIG. If you want to further improve the rust prevention between the ring member 2 and the socket 1, when installing the ring member 2 in the socket 1,
It is preferable to coat the inside of the resin with resin. This resin layer 4 is made of a material that is heat resistant, does not deteriorate over a long period of time, and does not contain harmful components, so it does not elute harmful components, and silicone resin is harmless to the human body and satisfies each of these requirements. Moreover, it is one-component and has excellent workability. Once the resin has been injected as described above, the tube end 10a is screwed into the socket 1 and into the resin layer 4, as shown in FIG. 9, thereby forming a compacted resin filled layer 4a. Consolidated resin filled layer 4a
This ensures a favorable tightness between the tube end 10a and each member 1 and 2, so that the metal does not come into direct contact with the hot water and prevents steam from entering the tube end 10a and other parts. As a result, the occurrence of rust can be appropriately prevented for a long period of time. Figure 10 shows the details of screwing the male thread of the pipe body 10 into the socket 1. Manually tighten the male thread to the position a, which is the addition of the tolerance b to the standard length a of the male thread, and then tighten the pipe body 10. Tighten using a mechanical tool such as a wrench to the effective thread length f formed in the tube body 10, as shown in FIG. 10B. Through this mechanical tightening, the end surface of the male threaded pipe effectively enters the resin layer 4 to form the above-mentioned compacted resin filled layer 4a, and is covered by the compacted packed layer 4a to prevent the intrusion of steam and the like, thereby improving rust prevention. Get it effectively. next first
The table shows specific dimensions in mm for the male thread standard length a, its tolerance b, the effective thread length f, the socket female thread length s, its tolerance c, etc. for each diameter, and the female thread of socket 1. is the distance (X in FIG. 10B) that does not fit with the male thread of the tube body 10, but the end surface of the ring member 2 needs to be at least as long as this distance x. . However, since the male thread cut into the pipe body 10 is threaded on site, the diameter of the male thread becomes large (thread that does not meet JIS standards), so the above
If the distance is applied to the length of the ring member 2, it is possible that the end face of the male threaded pipe will not come into contact with the resin, so it is preferable to take a length that is about 1.5 times the length of the above-mentioned X, with a margin. . Also, when the thread is cut to a small diameter on-site, the end of the male threaded pipe may go deep into the socket 1 and come into contact with the ring member 2, but this can be prevented because the end of the pipe is sufficiently covered with resin. Rust is sufficiently maintained, and there is no need to specify the dimensions of the neck portion of the ring member 2 so much.

[Table] *Actual measurements of commercially available sockets When using the present invention as explained above, the connected pipe ends of this type of hot water supply pipe threaded joint have a pipe end receiving recess formed by taking a step of the elastic ring member. The seal is not only received in the pipe section and embedded in the resin filling layer, but also has sufficient airtightness for the pipe end because a compacted filling layer is formed by screwing the pipe end. An effective rust prevention relationship can be ensured with
Furthermore, since the socket is made of elastic resin without using adhesives, it is easy to remove the socket during piping work, and the socket can be reused. Both methods do not generate or elute harmful components to the human body, so they can be applied in any situation, and strong compaction filling can be achieved using screws without requiring any special skills. Therefore, it has the effect of being generally easy to adopt and construct, and is a device with great practical effects.

[Brief explanation of the drawing]

The drawings show the technical content of the present invention; Fig. 1 is a partial sectional view showing an example of a conventional hot water pipe joint, and Fig. 2 is a sectional view of the end of the pipe and its core. FIG. 3 is an enlarged explanatory diagram showing the rust occurrence site in the connected state, FIG. 4 is a cross-sectional explanatory diagram of another conventional joint structure, and FIG. 5 is an explanatory diagram of the joint structure according to the present invention. 6 is a sectional view showing the disassembled state of the constituent parts, FIG. 7 is a sectional view showing the fitted state of those parts, FIG. 8 is a sectional view of the resin injected state, and FIG. FIG. 9 is a cross-sectional view of the tubular end inserted, and FIG. 10 is an explanatory diagram of the operation of screwing the tubular end into the socket. However, in these drawings, 1 is a socket,
2 is a ring member; 3 is a recessed portion facing the tube end; 4
4a is the injected resin layer, 4a is the compacted filling layer by screwing the end of the tube, 5 is the ring receiving recess, 10 is the tube body, 10
a indicates the end.

Claims (1)

[Scope of utility model registration request] The socket to which the end of the tube body is attached has a tube end receiving portion and is equipped with a ring member made of rubber or the like that does not generate substances harmful to the human body, and recesses for receiving the tube end are provided on both end surfaces of the ring member. A threaded joint for a hot water supply pipe, characterized in that a filling layer of a harmless resin such as silicone resin is formed between the socket, the ring member, and the pipe end as a compacted filling layer by screwing the socket into the pipe end.