JP3017427U - Rigid vinyl chloride lined steel pipe with branch pipe - Google Patents

Abstract

(57) [Abstract] [Purpose] To increase the joint strength between the lining layer of the main pipe and the brim short pipe inserted into the branch pipe at the branch portion of the hard vinyl chloride lining steel pipe. A lining layer 3 is formed on the inner surface of the main pipe 1, and the lining layer 3 has a cylindrical rising portion 3a extending so as to project into the branch pipe 2. A short tube 4 with a collar is inserted into the branch tube 2. The bridging short tube 4 and the lining layer 3 are made of hard vinyl chloride. Then, the rising portion 3 a and the bridging short pipe 4 are joined by the welded portion 5 and the adhesive portion 6.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a steel pipe having a branch pipe and lined with hard vinyl chloride, and particularly to a lining layer made of hard vinyl chloride formed on the inner surface of the main pipe and a hard vinyl chloride inserted into the branch pipe. This is related to the joint structure with a short pipe with a collar.

[0002]

[Prior art]

 Conventionally, a technique for lining the inner surface of a steel pipe is known. One of them is a technique of lining the inner surface of a steel pipe using a hard vinyl chloride pipe. Hereinafter, a steel pipe lined with such a hard vinyl chloride pipe (hereinafter, simply referred to as "hard vinyl chloride lining steel pipe") will be described.

When the hard vinyl chloride lining steel pipe has a branch pipe, a short pipe with a collar made of, for example, hard vinyl chloride is inserted into the branch pipe, and the short pipe with the flange and the main pipe of the hard vinyl chloride lining steel pipe are The surface lining layer is joined at the branch of the main pipe and the branch pipe. FIG. 7 is a partial cross-sectional view of a branch portion of a conventional hard vinyl chloride lined steel pipe having a branch pipe.

Referring to FIG. 7, a branch pipe 2 is provided in the main pipe 1 so as to communicate with the inside of the main pipe 1. A lining layer 3 made of hard vinyl chloride is formed on the inner surface of the main pipe 1. On the other hand, in the branch pipe 2, a brim short pipe 4 made of hard vinyl chloride is inserted. Then, the lower end of the collared short pipe 4 and the end of the lining layer 3 are welded. Conventionally, this welding is generally performed while supplying hard vinyl chloride to the welded portion. Therefore, as shown in FIG. 7, the welded portion 12 is formed so as to rise and project inward of the branch pipe 2. Due to the formation of the welded portion 12, relatively large thermal stress is generated in the collared short pipe 4 and the lining layer 3, so that the rising height H1 of the lining layer 3 into the branch pipe 2 is kept small. As a result, in the conventional example, the rising height H1 of the lining layer 3 is extremely small, about 3 to 4% or less, with respect to the height H of the branch pipe 2 from the inner surface of the main pipe 1. It was.

[0005]

[Problems to be solved by the device]

 The rigid vinyl chloride lined steel pipe having the above-mentioned conventional branch pipe has two problems as described below.

First, the first problem will be described. As described above, the rising height H1 of the lining layer 3 is small in view of the thermal stress during welding. Therefore, the overlapping length between the collared short pipe 4 and the lining layer 3 was also short. As a result, the joining of the brim short pipe 4 and the lining layer 3 was mainly carried out by the welded portion 12. Therefore, when some kind of relatively large internal stress occurs in the lining layer 3 or the collared short pipe 4, the lining layer 3 may be separated from the collared short pipe 4. Therefore, conventionally, it has been desired to further firmly bond the lining layer 3 and the brim short pipe 4 together.

Next, the second problem will be described. As shown in FIG. 7, the welded portion 12 is formed so as to project inward of the branch pipe 2. As a result, the substantial inner diameter d 2 of the branch pipe 2 becomes small. Therefore, there is also a problem that the flow path resistance increases.

The present invention has been made to solve the above problems. One purpose of this idea is to increase the joint strength between a lining layer formed on the inner surface of the main pipe and a brim short pipe inserted into the branch pipe in a hard vinyl chloride lining steel pipe having a branch pipe. .

Another object of the present invention is to increase the joint strength between a lining layer formed on the inner surface of the main pipe and a brim short pipe inserted into the branch pipe in a hard vinyl chloride lining steel pipe having a branch pipe, and to increase the branch strength. It is also to reduce the flow path resistance in the pipe.

[0010]

[Means for Solving the Problems]

 A hard vinyl chloride lining steel pipe according to the present invention comprises a main pipe, a branch pipe, and a brim short pipe. A lining layer made of hard vinyl chloride is formed on the inner surface of the main pipe. The branch pipe communicates with the main pipe. The brim short pipe is made of hard vinyl chloride and is inserted into the branch pipe so as to cover the inner surface of the branch pipe. The lining layer includes a tubular rising portion that protrudes into the branch pipe so as to overlap a part of the flanged short pipe, and has a cylindrical rising portion having a portion extending substantially parallel to the wall surface of the branch pipe. The short pipe with a collar is a welded part formed by melting the upper end of the rising part and the short pipe with a flange, and the boundary part between the rising part and the short pipe with a collar located below the welded part. It is joined by both the adhesive portion formed using an adhesive agent.

The length of the adhesive portion in the longitudinal direction of the branch pipe is preferably longer than the length of the welded portion in the longitudinal direction of the branch pipe. The penetration depth of the welded portion is preferably deeper than the penetration depth of the adhesive portion. Further, the height of the above-mentioned rising portion from the inner surface of the main pipe is preferably about 30% to about 60% of the height of the branch pipe from the inner surface of the main pipe. In addition, the welded portion is preferably formed by applying ultrasonic waves to the upper end of the rising portion and the brim short pipe located in the vicinity thereof, and the surface of the welded portion is formed to have a greater branch surface than the inner surface of the rising portion. Located on the wall side.

[0012]

[Action]

 In the hard vinyl chloride lining steel pipe according to the present invention, the lining layer includes the rising portion having the portion extending substantially parallel to the wall surface of the branch pipe. Then, a welded portion is formed at the boundary between the upper end of the rising portion and the flanged short pipe, and an adhesive portion is formed below the welded portion. The welded portion is formed by melting the upper end portion of the rising portion and the brim short tube with each other. As described above, when the chemicals such as sulfuric acid are flown into the steel pipe, the welded part is formed by melting each at the boundary between the upper end of the rising part and the short pipe with a collar, and thus the welded part is formed. It is possible to effectively prevent the chemical solution from penetrating into the adhesive portion below the welded portion. In the present invention, the welded portion mainly has a sealing function for preventing the chemical liquid or the like from penetrating into the adhesive portion. On the other hand, the bonding strength between the rising portion and the flanged short pipe is mainly carried by the adhesive portion. Therefore, by forming the adhesive portion over a wide range, it becomes possible to increase the bonding strength between the rising portion and the flanged short pipe. Here, as described above, in the present invention, since the welded portion only needs to have a sealing function of preventing the permeation of the chemical liquid, the welded portion is swelled while supplying hard vinyl chloride as in the conventional example. No need to form. Therefore, thermal stress due to the formation of the welded portion does not occur as in the conventional example. As a result, the height of the rising portion (rising height) can be increased. As a result, the rising portion can have a portion extending substantially parallel to the wall surface of the branch pipe, and the overlap length between the rising portion and the collared short pipe can be increased. As a result, it is possible to form the bonded portion over a wide range, and it is possible to increase the bonding strength between the rising portion and the collared short pipe.

Further, when the height of the rising portion from the inner surface of the main pipe is set to about 30% to about 60% of the height of the branch pipe from the inner surface of the main pipe, the tensile strength of the hard vinyl chloride pipe becomes The inventors of the present invention have found that almost the same tensile strength can be obtained. That is, it becomes possible to significantly improve the bonding strength between the lining layer and the collared short tube.

Further, the surface of the welded portion is located closer to the wall surface of the branch pipe than the inner surface of the rising portion. That is, the welded portion is formed so as not to project inward of the branch pipe. As a result, it becomes possible to increase the substantial inner diameter of the branch pipe as compared with the conventional example. This makes it possible to reduce the flow path resistance in the branch pipe.

[0015]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a partial sectional side view showing an embodiment of the present invention. FIG. 2 is an enlarged view of the branch portion in FIG.

First, referring to FIG. 1, a hard vinyl chloride lining steel pipe according to the present invention includes a main pipe 1 and a branch pipe 2. A lining layer 3 made of hard vinyl chloride is formed on the inner surface of the main pipe 1. On the other hand, a short tube 4 with a collar made of hard vinyl chloride is inserted into the branch tube 2. Then, one end of the lining layer 3 extends into the branch pipe 2, and in the branch pipe 2, the lining layer 3 and the bottom portion of the collared short pipe 4 are overlapped.

Then, a welded portion 5 and an adhesive portion 6 are formed at the boundary between the lining layer 3 and the collared short tube 4. The lining layer 3 and the collared short pipe 4 are joined by the welded portion 5 and the adhesive portion 6. The welded portion 5 is a portion formed by melting the base materials of the lining layer 3 and the collared short tube 4 without replenishing the hard vinyl chloride with each other. The adhesive portion 6 refers to a joint portion formed at the boundary between the lining layer 3 and the collared short pipe 4 by using an adhesive mainly composed of hard vinyl chloride resin or the like. To do.

Next, the features of the present invention will be described in detail with reference to FIG. Referring to FIG. 2, the lining layer 3 has a cylindrical rising portion 3 a so as to project into the branch pipe 2. Then, a welded portion 5 is formed at the boundary between the upper end of the rising portion 3a and the collared short pipe 4, and the welded portion 5 is adhered to the boundary portion between the rising portion 3a located below the welded portion 5 and the collared short pipe 4. The part 6 is formed. The welding portion 5 mainly has a sealing function of preventing a drug or the like flowing in the branch pipe 2 from penetrating into the welding portion 6. The adhesive portion 6 mainly has a function of ensuring the joint strength between the rising portion 3a and the collared short tube 4. As described above, the welding portion 5 is provided at the upper end portion of the rising portion 3a, whereby it is possible to effectively prevent the chemical solution from penetrating into the adhesion portion 6. Thereby, the adhesive portion 6 is protected from the chemical liquid, and the bonding strength is maintained.

Further, in the present invention, the rising height H1 of the rising portion 3a from the inner surface of the main pipe 1 can be made significantly higher than the conventional example. It is based on the following reasons. The welded portion 5 may have the sealing function as described above. Therefore, unlike the conventional example, it is not necessary to form the welded portion so as to rise while reinforcing the hard vinyl chloride. As a result, it is possible to reduce the thermal stress caused by the formation of the welded portion 5 as compared with the conventional example. This makes it possible to increase the rising height H1. Therefore, it is possible to increase the overlap length between the rising portion 3a and the collared short pipe 4. As a result, the adhesive portion 6 can be formed over a wide range. This makes it possible to increase the joint strength between the rising portion 3a and the collared short pipe 4.

As the rising height H1 of the rising portion 3a increases, the rising portion 3a has a portion extending substantially parallel to the wall surface of the branch pipe 2. Along with this, the adhesive portion 6 is also formed so as to extend substantially parallel to the wall surface of the branch pipe 2. Further, as shown in FIG. 2, the length of the adhesive portion 6 in the longitudinal direction of the branch pipe 2 is longer than the length of the welded portion 5 in the longitudinal direction of the branch pipe 2. Further, the penetration depth of the welded portion 5 is deeper than the penetration depth of the adhesive portion 6.

Further, in the present invention, in order to increase the joint strength between the rising portion 3a and the collared short tube 4, the following measures are taken. That is, with respect to the height H of the branch pipe 2 from the inner surface of the main pipe 1, the value of the rising height H1 of the rising portion 3a is optimized. Table 1 shows the height H of the branch pipe 2 from the inner surface of the main pipe 1, the rising height H1 of the rising portion 3a from the inner surface of the main pipe 1, and the ratio of H1 to H. Has been done.

[0022]

[Table 1] As shown in Table 1, the ratio of H1 to H is preferably about 30% to about 60%. By setting the ratio of H1 to H within this range, the joint strength between the rising portion 3a and the collared short pipe 4 should be approximately the same as the tensile strength of a pipe made of hard vinyl chloride. The inventors of the present invention have found that this is possible.

Incidentally, in the conventional example, the value of H1 / H was about 3 to 4% at most. Therefore, it is considered possible to increase the bonding strength as compared with the conventional example by making it larger than this value. For example, even if the value of H1 / H is about 10 to 20%, it is presumed that the joining strength between the rising portion 3a and the collared short pipe 4 can be increased as compared with the conventional example. It

Further, as shown in FIG. 2, the surface of the welded portion 5 is located closer to the wall surface side of the branch pipe 2 than the inner surface of the rising portion 3a. That is, unlike the conventional example, the welded portion 5 corresponding to the welded portion 12 does not project inward of the branch pipe 2. Thereby, the substantial inner diameter of the branch pipe 2 can be increased, and the flow path resistance of the fluid flowing in the branch pipe 2 can be reduced as compared with the conventional example.

Next, a method for manufacturing a hard vinyl chloride lining steel pipe according to the present invention will be described with reference to FIGS. 3 to 6. 3 to 6 are sectional views showing characteristic first to fourth steps of the manufacturing process of the hard vinyl chloride lining steel pipe according to the present invention.

First, referring to FIG. 3, a hard vinyl chloride pipe that has been heated and softened is inserted into the main pipe 1, and the inner surface of the main pipe 1 and the hard vinyl chloride pipe are separated by air pressure (blow molding). It is brought into close contact and swells into the branch pipe 2. At this time, a jig 7 with a collar is previously inserted into the branch pipe 2 so as to cover the inner surface of the branch pipe 2. As a result, in the branch pipe 2, the rising portion 3a is formed along the inner surface of the jig 7. Reference numeral 13 is a backing plate having a hole 13a for receiving the jig 7.

After that, the jig 7 is removed from the branch pipe 2. Thereby, as shown in FIG. 4, a gap 8 is provided between the rising portion 3 a and the branch pipe 2. In addition, the rising portion 3a has a portion that is separated from the inner wall surface of the branch pipe 2 via this gap 8 and extends substantially parallel to the inner wall surface of the branch pipe 2. After that, the head portion of the rising portion 3a is subjected to a cutting process to form a hole in the head portion of the rising portion 3a.

Next, as shown in FIG. 5, a brim short pipe 4 made of hard vinyl chloride is inserted into the branch pipe 2 so as to cover the inner surface of the branch pipe 2. At this time, an adhesive for vinyl chloride (for example, an adhesive containing vinyl chloride resin as a main component) is applied to the inner surface of the collared short tube 4 in advance. Then, the bottom portion of the collared short tube 4 is inserted into the gap 8 shown in FIG. After that, the elastic body 9 made of rubber or the like is inserted into the branch pipe 2. At this time, the elastic body 9 is provided with a through hole 9a, and the flange jig 10 is previously inserted into the through hole 9a. Then, as shown in FIG. 5, the collar portion of the collar jig 10 is arranged in the main pipe 1. Then, the pressing plate 11 having the through hole 11a in the central portion is arranged so as to cover the elastic body 9 and the flange portion of the branch pipe 2, and one end of the bridging jig 10 is projected through the through hole 11a. Then, the elastic body 9 is expanded in the branch pipe 2 by pulling up one end of the collar jig 10 in the direction of the arrow shown in FIG. Thereby, the rising portion 3a is pressed against the collared short pipe 4.

Next, the elastic body 9, the bridging jig 10 and the backing plate 11 are removed, and the above adhesive is dried. Thereby, the welded portion 6 is formed. After that, for example, ultrasonic waves are applied to the upper end portion of the rising portion 3a and the brim short tube 4 to melt the upper end portion of the rising portion 3a and the brim short tube 4 in the vicinity thereof. Thereby, the co-welding of the base materials is performed between the bridging short pipe 4 and the upper end of the rising portion 3a. Thereby, the welded portion 5 is formed. Through the above steps, the hard vinyl chloride lining steel pipe shown in FIG. 1 is formed.

[0030]

[Effect of device]

 As described above, according to the present invention, the overlap length between the lining layer on the inner surface of the main pipe and the collared short pipe inserted into the branch pipe can be made longer than in the conventional example. Thereby, it becomes possible to form the adhesive portion over a wide range. As a result, it becomes possible to increase the connection strength between the lining layer and the collared short pipe. Further, a welded portion is formed at the boundary between the upper end of the rising portion of the lining layer protruding into the branch pipe and the collared short pipe. Since the welded portion has excellent sealing properties, it is possible to effectively prevent the chemical solution from penetrating into the adhesive portion. As a result, it becomes possible to effectively prevent a decrease in the bonding strength of the adhesive portion due to the infiltration of the chemical liquid. From the above, according to the present invention, the rigid vinyl chloride is excellent in the bonding strength between the lining layer and the short pipe with a collar at the branch portion and can prevent the deterioration of the bonding strength due to the invasion of a chemical solution into the bonding portion. A lining steel pipe is obtained.

Further, the surface of the welded portion does not project inward of the branch pipe 2 unlike the welded portion in the conventional example. As a result, the substantial inner diameter of the branch pipe can be made larger than that of the conventional example. As a result, the flow path resistance of the branch pipe can be reduced.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional side view showing a hard vinyl chloride lining steel pipe according to the present invention.

FIG. 2 is a partially enlarged view of a branch portion of the hard vinyl chloride lining steel pipe shown in FIG.

FIG. 3 is a sectional view showing a characteristic first step in the manufacturing process of the hard vinyl chloride lining steel pipe according to the present invention.

FIG. 4 is a sectional view showing a characteristic second step of the manufacturing process of the hard vinyl chloride lining steel pipe according to the present invention.

FIG. 5 is a sectional view showing a characteristic third step of the manufacturing process of the hard vinyl chloride lining steel pipe according to the present invention.

FIG. 6 is a sectional view showing a characteristic fourth step of the manufacturing process of the hard vinyl chloride lining steel pipe according to the present invention.

FIG. 7 is a partially enlarged sectional view of a branch portion of a conventional hard vinyl chloride lining steel pipe.

[Explanation of symbols]

 1 Main Pipe 2 Branch Pipe 3 Lining Layer 4 Short Pipe with Collar 5 Welding Part 6 Adhesive Part 3a Rising Part

Claims (5)

[Scope of utility model registration request] 1. A main pipe having a lining layer made of hard vinyl chloride formed on an inner surface thereof, a branch pipe communicating with the main pipe, and a branch pipe inserted so as to cover the inner surface of the branch pipe,
A short pipe with a collar made of hard vinyl chloride, wherein the lining layer projects into the branch pipe so as to overlap a part of the short pipe with the collar, and has a portion having a portion extending substantially parallel to the wall surface of the branch pipe. A rising portion, and the rising portion and the brim short pipe, the upper end of the rising portion and the brim short pipe are formed by melting each other, the welding portion, and the position below the welding portion. A hard vinyl chloride lined steel pipe having a branch pipe, which is joined to both the rising portion and the boundary portion between the flanged short pipe by an adhesive portion formed by using an adhesive. 2. The rigid vinyl chloride lining with a branch pipe according to claim 1, wherein the length of the adhesive portion in the longitudinal direction of the branch pipe is longer than the length of the welded portion in the longitudinal direction of the branch pipe. Steel pipe. 3. The hard vinyl chloride lining steel pipe having a branch pipe according to claim 1, wherein the penetration depth of the welded portion is deeper than the penetration depth of the adhesive portion. 4. The height of the rising portion from the inner surface of the main pipe is about 3 times the height of the branch pipe from the inner surface of the main pipe.
A rigid vinyl chloride lined steel pipe with branch pipes according to claims 1 to 3, which is 0% to about 60%. 5. The welded portion is formed by applying ultrasonic waves to an upper end portion of the rising portion and the collared short pipe located in the vicinity thereof, and the surface of the welded portion is formed within the rising portion. A hard vinyl chloride lining steel pipe having a branch pipe according to claim 1, which is located closer to a wall surface side of the branch pipe than a surface thereof.