JPS63168234A - Tubular body connection method - Google Patents

Abstract

PURPOSE:To save a labor by reducing the executing man/hour at connection time by giving a mechanical force by outer-inserting the connection pipe forming the excess metal part plastically deformable the pipe end part of the tubular body to be connected. CONSTITUTION:The elbow 3 having the pipe end part whose diameter is expanded to the inner bore about equal to the outer bore dimension of a tubular body 2 is outer-inserted with its adhesion to the pipe end part of both steel pipes 2, 2 in an equal bore. Plural excess metal parts 3a of annular projections in rectangular section projecting to the external part in the radial direction are formed on the outer periphery close to both end parts of this elbow 3, which is composed of a plastically deformable material. For instance the die 4 of a split die is located so that its tapered face 4a may approach to the excess metal part 3a and a anchor 7 is stationarily located in the zone transferring to the diameter expanding part of the elbow 3 to forcibly move the die 4 in the axial direction by a driving means. As a result the plastic deformation to the inner part in the radial direction is caused on the corresponding part to the excess metal part 3a of a thin tubular body 2 as well according to the excess metal part 3a being deformed to the inner part in the radial direction and the part 3 is adhesively bitten to the deformed part of the tubular body 2.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION This invention relates to a method for connecting tubes, and more particularly to thin-walled metal tubes such as stainless steel tubes.

When interconnecting pipes through intermediate connecting pipes such as elbows, T-shaped pipes, and U-shaped pipes, construction labor and costs can be reduced, and high connection strength and adhesion of the connected parts can be achieved. This relates to the connection method.

BACKGROUND OF THE INVENTION Various joint construction methods are used to connect water supply and drainage pipes used in water facilities such as air conditioning equipment, hot water supply equipment, and flush toilets in high-rise buildings such as condominiums and office buildings.

By the way, buildings using structural materials such as concrete generally have a durable lifespan of 40 to 60 years.
The service life of the water supply and drainage pipes used for this is about 15 years. For this reason, piping facilities need to be replaced about three to four times per one life cycle of a building.

Most of the pipe connections associated with the installation of such water supply and drainage pipes are performed at the construction site, so rapid workability and ease of handling are required in order to shorten the construction period. In addition, since the lifespan of conventional piping itself is as described above,
Recently, from the beginning of construction, we have selected and used materials such as stainless steel, which have excellent durability even though they are more expensive.
There is a trend toward reconsidering the connection method, which makes piping construction easier and provides better watertightness after pipe connection.

In this regard, if we briefly consider the changes in materials used in conventional water supply and drainage pipes, we can see that in the past, thick-walled galvanized steel pipes
This is because it is rust-resistant, inexpensive, and can be easily connected by threading the outer periphery of the tube end and screwing in a connecting tube-shaped nut.

Widely used in place of lead pipes and steel pipes. However, due to the recent deterioration in water quality, galvanized steel pipes have been found to have disadvantages such as zinc leaching and severe corrosion in the exposed parts of the steel pipes. Most of it has moved to . This steel pipe is a composite pipe that uses a thick steel pipe for the outer layer and is lined with vinyl chloride for the inner layer, and has excellent corrosion resistance and mechanical strength.

Most of the connections are threaded connections using connecting tubular nuts.

Furthermore, in recent years, thin-walled stainless steel pipes, which already have a high reliability and track record as piping materials in various plants, have become popular.
In particular, it has begun to be used as a piping material in buildings for water and hot water supply. Although the purchase price of this stainless steel pipe is higher than that of other pipe materials, its corrosion resistance is outstanding, and the Japan Water Works Association standards have recently been established, and its use is likely to increase. In addition, water supply and distribution pipes may be connected to each other through connecting pipes such as elbows, T-shaped pipes, or U-shaped pipes at some corners of buildings or in multiple branch supply systems. It is increasing.

Problems to be Solved by the Invention As mentioned above, the use of thin-walled stainless steel pipes has become popular in recent years. For example, in the solder type shown in FIG. 15, the ends of the stainless steel pipes 2 to be connected are inserted into the enlarged diameter ends of the elbows 1 as connection pipes, and soldered. It is something to attach. Moreover, the press type shown in FIG. 16(a) is as follows.

Insert the tube body 2 into the expanded tube end of the elbow 1, which is formed by fitting the O-ring 9 into the outer radiused portion, and tighten it using a special press tool as shown in FIG. 16(b). no r
The pipes are connected by caulking. However, the former method requires skill in soldering stainless steel, which is generally difficult, and requires special blanks, which takes time and effort, so it is not common. In addition, there are disadvantages such as the need for expensive specialized tools.

Furthermore, a compression method has been proposed in which a connecting tube is inserted into the connecting portion and tightened with a cap nut, but this method increases the unit cost and is not common.

Purpose of the Invention The present invention has been proposed in order to suitably solve the above-mentioned drawbacks when connecting thin-walled metal steel pipes, particularly stainless steel pipes, through connecting pipes such as elbows and T-shaped pipes. The number of construction steps at the time of connection is reduced,
It is an object of the present invention to provide a new connection method that saves labor and costs, and also ensures sufficient connection strength and airtightness of the connection part after construction.

Means for Solving the Problems In order to overcome the above-mentioned problems and achieve the intended purpose, the present invention provides a system that allows plastic deformation of the circumferential surface near the open end of the pipe end of the pipe body to be connected. A connecting pipe formed with a thick extra wall is inserted, and then a mechanical force is applied to the extra thick part of the connecting pipe to deform the extra wall inward in the radial direction, whereby the pipe to be connected is It is characterized in that the outer circumferential surface corresponding to the extra flesh portion of the body is deformed inward in the radial direction, and the tube bodies are connected via a connecting tube.

Embodiments Next, the method for connecting tubes according to the present invention will be described below with reference to preferred embodiments and the accompanying drawings. As for the two pipes to be connected to each other, the thin-walled stainless steel pipes mentioned above are suitable for connection, but any other metal pipes that can be plastically deformed can be used. The present invention is applicable to any thick-walled tube.

1 and 2, the case where two thin-walled stainless steel pipes 2, 2 are connected at an angle of 90° is explained. An elbow 3 having a tube end whose diameter is enlarged to an inner diameter substantially equal to the outer diameter of the tube body 2 is tightly inserted. This elbow 3
As shown in FIG. 1, on the outer periphery near both ends thereof, there is an extra wall portion 3a consisting of an annular protrusion with a rectangular cross section that protrudes outward in the radial direction.
Multiple pieces are formed. The material of the elbow 3 is not particularly limited as long as it is a metal that can be plastically deformed and has excellent corrosion resistance and mechanical strength. However, in the case of a metal different from that of the tube body 2, depending on the combination Since durability and watertightness deteriorate over time due to electrolytic corrosion, it is preferable that the elbow 3 is made of the same type of metal as the metal that constitutes the tube body 2.

In this state that the elbow 3 is inserted into both tube bodies 2, 2, a die 4 made of a split mold that can be divided into two halves, for example, is placed around the outer periphery of one tube body 2 as shown in the figure. do. The open end of the die 4 has a trumpet-shaped tapered surface 4a.
is formed. Note that the dimensions of the tapered surface 4a are set to a value that allows the excess thickness 3a formed in the elbow 3 to pass through only by deforming the excess thickness 3a inward in the radial direction.

The die 4 is positioned so that its tapered surface 4a is close to the corresponding extra wall portion 3a of the elbow 3, and the anchor 7 is fixedly positioned in the area transitioning to the enlarged diameter portion of the elbow 3. The dice 4 are driven by a driving means (not shown) such as the like.

It is forcibly moved in the axial direction shown by the arrow in FIG. As a result, the die 4 has the elbow 3 on its tapered surface 4a.
As a result, the excess thickness 3a is deformed inward in the radial direction as shown in FIG.

As the extra wall portion 3a deforms inward in the radial direction, the thin tube 2 also undergoes plastic deformation inward in the radial direction at a portion corresponding to the extra wall portion 3a. For this reason, the deformed portion of the extra wall portion 3a bites tightly into the deformed portion of the tube body 2, and a reliable connection between the two tube bodies 2, 2 by the elbow 3 is achieved. Next, the other pipe body 2 and elbow 3
The connection with is also carried out in exactly the same procedure as shown in FIG.

Next, the embodiment shown in FIGS. 3 and 4 shows a case where a T-shaped pipe is used as the connecting pipe.

However, the extra wall portion 3a of the T-shaped tube 3 is formed of a plurality of annular protrusions (ribs) that protrude radially outward from the circumferential surface, and a steel ring 5 is fitted into the recess 3b of the annular protrusion. has been done.

In the case of this embodiment as well, the die 4 having the above-mentioned configuration is positioned so that its tapered surface 4a is close to the corresponding extra wall portion 3a of the T-shaped tube 3, and the die 4 is moved to the enlarged diameter portion of the T-shaped tube 3. The anchor 7 is fixedly positioned in the area. Then, the die 4 is driven by a driving means such as hydraulic pressure, and is forcibly moved in the axial direction shown by the arrow in FIG. This applies mechanical stress in the axial direction to the extra wall portion 3a of the T-shaped tube 3, plastically deforms the extra wall portion 3a inward in the radial direction, and correspondingly deforms the tube body 2 to form the T-shaped tube. In this case, since the steel ring 5 is used for connection by the pipe 3, the biting property is improved and the watertightness and airtightness are further improved. Incidentally, the connection between the other tube body 2 and the T-shaped tube 3 is also performed in exactly the same manner as shown in FIG. 4.

In the embodiment shown in FIGS. 5 and 6, the outer periphery of each end of the elbow 3 serving as a connecting pipe is rounded with a rounded rim, and this rim portion functions as an extra wall portion 3a. There is. In this case as well, the tapered surface 4a of the die 4 is
By positioning the anchor 7 close to the corresponding surplus portion 3a of the elbow 3, fixing the anchor 7 in the area transitioning to the enlarged diameter portion of the elbow 3, and forcibly moving the die 4 toward the anchor 7, the surplus of the elbow 3 is removed. The flesh portion 3a is given axial straining. As a result, the corresponding portion of the tube body 2 is deformed into the shape of an annular groove, and a reliable connection between the elbow 3 and the tube body 2 is achieved. In the illustrated example, the metal ring 5 is inserted into this rim portion, but this is not necessarily a requirement. Subsequently, the other tube body 2 and the T-shaped tube 3 are connected in exactly the same procedure as shown in FIG.

FIGS. 7 and 8 show that a thick extra wall portion 3a (horizontal in longitudinal section) consisting of a tapered surface that slopes toward the open end is formed at each end of the elbow 3 serving as a connecting pipe. has been done. A nut 6 screwed into a female thread cut on the outer periphery of the elbow 3 is used as a means for pressing and moving the die 4, and an anchor 7 that can be divided into two halves is used as a means for fixing the elbow 3. It is a pressure arrangement. In this state, if the nut 6 is rotated and the die 4 is forcibly propelled in the direction of the arrow, the excess wall portion 3a will be removed from the die 4.
It is restricted by this and loses a place to escape in the radial direction, and therefore deforms inward in the radial direction as shown in FIG.

In this case, an annular protrusion 3c that protrudes radially inward is provided at the center of the inner peripheral surface of the elbow 3, and the pipe end of each tube body 2 is brought into contact with this, but this is not necessarily the case. It's not a requirement. Subsequently, the other tube body 2 and the T-shaped tube 3 are connected in exactly the same manner as shown in FIG.

FIGS. 9 and 10 show still another embodiment, in which extra wall portions 3a consisting of rounded portions are formed at both ends of an elbow 3 serving as a connecting pipe. In addition, an anchor 7 for receiving a reaction force is detachably fixed to the region of the elbow 3 that transitions to the enlarged diameter portion as shown in the figure, and the die 4 is removed from the enlarged transition region of the elbow 3 and the surplus portion 3a. Next, the die 4 is driven by a means such as a hydraulic cylinder to forcibly move it in a direction away from the anchor 7, so that the surplus portion 3a of one side of the elbow 3 is moved in the axial direction. It will be destroyed. As a result, the extra wall portion 3a is deformed inward in the radial direction, as shown on the right side of FIG.

The tubular body 2 also undergoes plastic deformation inward in the radial direction at a portion corresponding to the extra wall portion 3a, and one of the tubular bodies 2 and the elbow 3 are connected. Subsequently, the connection between the other pipe body 2 and the elbow 3 is carried out in exactly the same procedure as shown in FIG.

11 and 12 show another embodiment of the present invention, and the basic shape of the elbow 3 is the same as that shown in FIG. 9. However, the die 4 is set in the vicinity of the opening end of the elbow 3 outside the excess wall portion 3a. Further, the anchor 7 that receives the reaction force is detachably fixed to the region of the elbow 3 that transitions to the enlarged diameter portion. In this state, the dice 4
is driven by a means such as a hydraulic cylinder to forcibly move it in the direction of approaching the anchor 7, thereby squeezing the excess wall portion 3a of one side of the elbow 3 in the axial direction. As a result, as shown on the right side of FIG.

The extra-thickness portion 3a deforms inward in the radial direction, and the tubular body 2 also undergoes plastic deformation inward in the radial direction at a portion corresponding to the extra-thickness portion 3a, causing one of the tubular bodies 2 and the elbow 3 to deform. connection is made. The connection between the other pipe body 2 and the elbow 3 is also carried out in exactly the same procedure as shown in FIG.

FIGS. 13 and 14 show still another embodiment of the present invention, in which the tube bodies are connected by applying compressive force in the axial direction to the T-shaped tube 3. FIG. That is, on the outer periphery of each end of the T-shaped tube 3, an extra wall portion 3a having the shape shown in the figure is formed, and on the outer periphery of the T-shaped tube 3, there is a split holder that restricts the escape of the extra wall portion 3a to the outside in the radial direction. 8 to securely grasp and fix the T-shaped tube 3. Each end of the holder 8 is formed with a trumpet-shaped tapered surface 8a that abuts and restricts the extra wall portion 3a when attached to the T-shaped tube 3. The thin portion 4b can enter into this tapered surface 8a.

In this state, if the die 4 is forcibly approached in the axial direction, each excess wall portion 3a of the T-shaped tube 3 is compressed by the thin wall portion 4b of the die 4, as shown in FIG. At this time, since the extra wall portion 3a is restricted from escaping radially outward by the holder 8, it inevitably deforms radially inward,
Accordingly, the tubular body 2 also undergoes plastic deformation inward in the radial direction at a portion corresponding to the extra wall portion 3a. Therefore, as in the previous embodiments, reliable connection of the tube body 2 by the T-tube 3 is achieved. Note that the connection between the other tube body 2 and the T-tube 3 is carried out in exactly the same procedure as shown in FIG. 14.

Effects of the Invention As described above, according to the pipe connection method according to the present invention, an intermediate connecting pipe such as an elbow, T-shaped pipe, or U-shaped pipe can be connected to the end of a thin metal pipe such as a stainless steel pipe. Simply by applying mechanical force to the connecting tube, the extra wall formed in the connecting tube is plastically deformed, and the corresponding tube is also deformed radially inward to establish a connection with the connecting tube. Therefore, the number of construction steps at the time of connection is reduced, resulting in labor saving and cost reduction.

Moreover, it has the advantage of ensuring sufficient connection strength and airtightness of the connected portion after construction. Furthermore, by applying adhesive, anti-friction agent, anti-corrosion agent, or anti-friction agent between the connecting pipe and the pipe body,
It is more preferable because connection strength, airtightness, watertightness, etc. are improved.

[Brief explanation of the drawing]

The drawings show a preferred embodiment of the pipe connection method according to the present invention, and FIG. 1 is a schematic cross-sectional view showing the direct stage of constructing the connection method according to the first embodiment, and FIG. is a schematic sectional view showing the state immediately after construction using the connection method shown in FIG. 1, FIG. 3 is a schematic sectional view showing the stage immediately before construction of the connection method according to the second embodiment, and FIG. A schematic sectional view showing the state immediately after construction using the connection method shown in the figure, FIG. 5 is a schematic sectional view showing the stage immediately before construction of the connection method according to the third embodiment, and 6 @ is shown in FIG. 5. A schematic cross-sectional view showing the state immediately after construction by the connection method, FIG. 7 is a schematic cross-section diagram showing the stage immediately before construction of the connection method according to the fourth embodiment, and FIG. 8 is a schematic cross-sectional view showing the state immediately after construction by the connection method shown in FIG. FIG. 9 is a schematic sectional view showing the state immediately after construction; FIG. 9 is a schematic sectional view showing the stage immediately before construction of the connection method according to the fifth embodiment;
The figure is a schematic sectional view showing a state immediately after construction using the connection method shown in FIG. 7, and FIG. 11 is a schematic sectional view showing a stage immediately before construction using the connection method according to the sixth embodiment. FIG. 12 is a schematic cross-sectional view showing the state immediately after construction using the connection method shown in FIG. 11; FIG.
Fig. 4 is a schematic cross-sectional view showing the state immediately after construction using the connection method shown in Fig. 13, and Figs. It is an explanatory sectional view showing an example. 2... Pipe body 3... Connection pipe body 4... Dice 6... Nut 7... Anchor
8...Holder FIG, 1 FIG, 2 FIG, 3! FIG. 4 FIG. 5 FIG. 6 FIG. 7 FIG. 8 FIo. 9 FIG. 10 FIG. 11 FIG. Relationship with Patent applicant Address: 66-4, Hoshizaki-cho, Minami-ku, Nagoya, Agent 6 Contents of amendment (1) The following is added to the next line of line 11 on page 9 of the specification. 17 and 18 show a modification of the bone connection method shown in FIG. 1, in which a sleeve bolt 10 and a socket nut 11 are used as means for forcibly moving the die 4. As shown in the figure, the sleeve bolt 1 has a through hole 10b through which the elbow 3 can be inserted.
0 is extrapolated to the region immediately before the pipe diameter of the elbow 3 is narrowed. The position of the sleeve bolt 10 in the axial direction is restricted by an annular convex portion 3d formed on the outer periphery of the elbow 3 and protruding in the radial direction, but this is not necessarily a requirement. A male thread is threaded on the outer periphery of the sleeve bolt 10 and can be threaded into a female thread threaded on the inner peripheral surface of a socket nut 11, which will be described later. Also, elbow 3 of sleeve bolt 10
A hexagonal head 10a is formed at the end opposite to the end facing the opening of the hexagonal head 10a, which can be engaged with, for example, a wrench (not shown). The sleeve bolt 10 is inserted across the extra wall portion 3a of the elbow 3.
A socket nut 11 is inserted through the socket nut 11, and a bag-shaped flange lla is formed at one end of the socket nut 11, and a through hole 11b through which the elbow 3 is inserted is formed in the center of the flange lla. is drilled. The opening 11C of the socket nut 11 through which the elbow 3 is inserted is oriented toward the sleeve bolt 10. Note that a hexagonal head lid that can be engaged with a wrench is formed at the end on the side where the flange lla is formed. Further, a die 4 is disposed in the hollow part of the socket nut 11 (between the inner circumferential surface of the nut and the outer circumferential surface of the elbow 3), and one end of the die 4 has a size that allows the extra wall part 3a to enter. A set trumpet-shaped tapered surface 4a is formed. The other end of this die 4 abuts against the flange lla of the socket nut 11. The structure is such that positional regulation is performed. A sleeve bolt 10 and a socket nut 11 are inserted facing each other around the outer periphery of the elbow 3 into which the pipe body 2 has been inserted, and when the ends of the sleeve bolt 10 and the socket nut 11 are screwed together, the sleeve The hexagonal head 10a of the bolt 1o is engaged with, for example, a wrench to restrict rotation, and the hexagonal head lid of the socket nut 11 is engaged with a wrench to rotate in the tightening direction. As a result, the socket nut 1-11 approaches the sleeve bolt 10 while being tightened with the sleeve bolt 10, and the die 4 is forcibly moved in the direction of the arrow. Therefore,
The die 4 has the extra wall portion 3a on its tapered surface 4a.
will be squeezed in the axial direction. The surplus portion 3a is regulated by the die 4 and has no place to escape radially outward, and as a result, is compressed and deformed radially inward as shown in FIG. 18. Along with this, the tube 2 also undergoes plastic deformation inward in the radial direction at a portion corresponding to the extra wall portion 3a, and a reliable connection between the tube 2 and the elbow 3 is achieved. Next, connect the other pipe body 2 and elbow 3. As shown in FIG. 18, the procedure is exactly the same. In this embodiment, by screwing the socket nut 11 into the sleeve pole l-10, the excess wall portion 3a of the elbow 3 is removed.
Because it was configured to cause plastic deformation. For example, connection work can be easily performed even in places where sufficient work space cannot be secured, such as near a wall or in a narrow space. Moreover, the springback of the tube body after compression deformation can be stopped by a die, a sleeve bolt, a socket nut, etc., and there is an advantage that the connection strength after construction and the airtightness of the connection part are sufficiently ensured. (2) The following is added on the next line of page 10, line 12. In the embodiment shown in FIGS. 19 and 20, when a T-shaped tube 3 is used as a connecting tube, there is a means for suppressing and moving the die 4 for plastically deforming the excess wall portion 3a of the 1-shaped tube 3. In this case, the sleeve bolt 10 and socket nut 11 shown in Figs. , the socket nut 11 is inserted with its axial movement restricted, and the die 4 is set in a position facing this sleeve bolt 10 with the extra wall portion 3a in between. is screwed into the sleeve bolt 10 and the die 4 is forcibly propelled in the direction of the arrow, thereby squeezing the excess wall portion 3a of the T-tube 3 in the axial direction. The flesh portion 3a is plastically deformed inward in the radial direction, and the tubular body 2 is also plastically deformed inward in the radial direction at a portion corresponding to the extra flesh portion 3a.
A connection is made between the and '1'-shaped tube 3. Subsequently, the connections between the other tube bodies 2, 2 and the 1-shaped tube 3 are made as shown in FIG.
It is carried out using exactly the same procedure. ” (3) On page 17, line 9, “This is a cross-sectional view.” shall be corrected as follows. 17 is a schematic sectional view showing the stage immediately before the connection method according to the modification of the embodiment shown in FIG. 19 is a schematic sectional view showing the stage immediately before implementing the connection method according to the modification of the embodiment shown in FIG. 3, and FIG. 20 is the connection method shown in FIG. 19. FIG. 17 FIG. 18 is a schematic cross-sectional view showing the state immediately after construction.

Claims (4)

[Claims] (1) A connecting tube formed with a plastically deformable excess wall on the circumferential surface near the open end is inserted into the end of the pipe body to be connected, and then a machine is inserted into the excess wall of the connecting tube. By applying a force, the extra wall portion is deformed radially inward, thereby deforming the outer circumferential surface of the tube to be connected corresponding to the extra wall portion radially inward, and the tube body is A method for connecting pipe bodies, characterized in that the connection is made through a connecting pipe. (2) The mechanical force applied to the connecting tube is an axial force applied to the outer periphery of the connecting tube, and the mechanical force is applied to the outer circumference of the connecting tube by forcibly moving both the tube bodies and the die inserted into the connecting tube in the axial direction. The pipe connection method according to claim 1, wherein the pipe body connection method is provided with ironing. (3) The pipe connection method according to claim 1 or 2, wherein an elbow is used as the connection pipe. (4) The pipe connection method according to claim 1 or 2, wherein a T-shaped pipe is used as the connection pipe.