WO2018235615A1

WO2018235615A1 - Tubular structure

Info

Publication number: WO2018235615A1
Application number: PCT/JP2018/021856
Authority: WO
Inventors: 進之助西島; 冨村　宏紀
Original assignee: 日新製鋼株式会社
Priority date: 2017-06-22
Filing date: 2018-06-07
Publication date: 2018-12-27
Also published as: JP6965594B2; JP2019007527A; TW201905370A

Abstract

Provided is a tubular structure that is easily processed at a construction site and that has an excellent pullout prevention property when coupled, even when the thickness of the tubular structure is small. The present invention is a tubular structure 100 provided with a tubular member 1 at the ends of which annular recesses 12 are formed, and a fitting ring 13 that has two outside surfaces 13c, 13b perpendicular to an axial line A of the tubular member 1, and that is pressed and secured against the outer circumference of the annular recesses 12. The fitting ring 13 is divided into a plurality of arc-shaped members 13a and 13b, and the arc-shaped members 13a and 13b, are coupled to each other by means of coupling members 14. In the coupled state the inner circumference of the fitting ring 13 is shorter than the outer circumference of the annular recesses 12 into which the fitting ring 13 is pressed and secured. Before being coupled the arc-shaped members 13a and 13b are arranged along the outer circumference of the annular recesses of the tubular member 1, and the arc-shaped members are then coupled to each other by means of the coupling members 14, thereby pressing and securing the tubular member 1 against the outer circumference of the annular recesses 12.

Description

Tubular structure

The present invention relates to tubular structures.

Conventionally, doug tile cast iron pipes are often used as tubular structures such as water pipes. The doug tile cast iron pipe is made of cast metal and has a high degree of freedom in shape. Because of this, there are many different types of joints, which are used in the right place.
On the other hand, although stainless steel (SUS) also exists as tubular structures, such as a water pipe, since processing of a joint is not easy, it is limited to a specific use. However, SUS tubes have a longer service life than doug tile cast iron tubes. Furthermore, problems such as red water and blue water are unlikely to occur, and stress corrosion cracking does not occur in a normal temperature environment, so running costs are low. Therefore, in the future, the use of SUS pipes for various applications is required.

Since the tubular member made of SUS has a low degree of freedom in shape as compared with the doug tile cast iron pipe, the same connection as the doug tile cast iron pipe is difficult.
For this reason, as a method of connecting the tubular structure made of SUS, conventionally, a convex portion is formed on the outer periphery of the tubular member by welding a square ring to the outer periphery of the tubular member, and the tube ends of the two tubular structures Are facing each other, and there is a method of disposing a housing on the outer periphery thereof (see Patent Document 1).

Further, the retaining member is mounted on the outer periphery of the tubular structure, the retaining member is reduced in diameter by the cap nut having a tapered surface, and the tube ends are joined by biting into the outer periphery of the annular structure of the retaining member. There is also a method which is carried out (see Patent Document 2).

Furthermore, there is also a method of connecting the tubes using a lock ring (see Patent Document 3). In this patent document 3, one groove in the circumferential direction is cut in a groove provided on the outer periphery of one tube end of two tubular structures to be connected, and a lock ring which can be elastically deformed on the large diameter side Fit in. The end of the tube of the other tubular structure is provided with a special shape for receiving the end of the tube on which the locking ring is fitted. Then, the push ring is disposed at a portion opposite to the pipe end with respect to the lock ring, and the tubular structure is connected by connecting the push ring and the specially shaped portion with the lock ring interposed therebetween.

Utility model registration No. 3171067 Japanese Patent Application Publication No. 2003-254476 JP 2008-309276

The tubular structure may be cut and connected to a predetermined length at the construction site and the corner ring is attached to the cut tube end. For this reason, in Patent Document 1, the square ring is welded to the cut tubular member at the construction site. However, it is difficult to guarantee the quality of welding at the construction site.

In Patent Document 2, since welding is not used, processing at a construction site is possible. However, the annular structure is fixed by reducing the diameter of the retaining member with the cap nut, and the diameter reduction of the retaining member is also limited, and it can not be said that the withdrawal prevention capability is sufficient.

Also in Patent Document 3, since welding is not used, processing at a construction site is possible. Moreover, since the lock ring is attached, it has the extraction prevention ability higher than patent document 2. FIG. However, since the lock ring is only inserted into the groove provided on the outer periphery of the tubular member by elastic deformation, the fixing force on the tubular member is not so strong. Furthermore, the shape of one end of the tubular structure is complicated and the number of parts is large. In addition, with cast iron pipes with a large wall thickness (for example, a thickness of 7.5 mm), sufficient groove depth can be secured for fitting the lock ring, but with stainless steel pipe thickness (for example, 3.0 mm) sufficient. It is difficult to machine depth grooves.

In view of these prior arts, the present invention has an object to provide a tubular structure which can be processed at a construction site and has a high extraction blocking ability when connected even if the wall thickness is thin. Do.

The present invention is a fitting ring having a tubular member having an annular recess formed at the end of the tube, and two outer side surfaces perpendicular to the axis of the tubular member, and pressed against and fixed to the outer periphery of the annular recess. And a tubular structure comprising:

The insertion ring is divided into a plurality of arc-shaped members, and the arc-shaped members are connected to each other by a connection member, and the inner periphery of the insertion ring in a connected state is pressed and fixed by the insertion ring The tubular member is shorter than the outer periphery of the annular recess to be connected, and the arc-shaped member before connection is disposed on the outer periphery of the annular recess of the tubular member, and the arc-shaped members are connected to each other by the connecting member. It is preferable to press and fix on the outer periphery of the annular recess.

The annular recess has two inner side surfaces perpendicular to the axis, and a bottom surface parallel to the axis, and the fitting ring is a square ring, and the two inner side surfaces of the annular recess and the inner side are fitted It is preferable that the two outer side surfaces of the insert ring substantially abut each other, and the bottom surface of the annular recess and the inner circumferential surface of the fitting ring abut.

It is preferable that the depth of the annular recess be equal to or less than half of the radial thickness of the tubular member.

One of the tube ends of the tubular member is an inlet, and the other is a socket having a larger diameter than the inlet,
It is preferable that the annular recess and the fitting ring are provided on at least one side of the insertion port or the receiving port.

The tubular member and the fitting ring are preferably formed of stainless steel.

According to the present invention, it is possible to provide a tubular structure which can be processed at a construction site and has a high withdrawal preventing ability when connected even if the wall thickness is thin.

It is sectional drawing which shows the state which connected two tubular structures concerning embodiment using a housing. FIG. 7 is a partial cross-sectional view of the tubular member without the snap ring attached. It is the fragmentary sectional view which showed the state which attached the fitting ring to the tubular member 1 of the state of FIG. It is a figure explaining an insertion ring, (a) is one divided perspective view, (b) is another divided perspective view, (c) shows the state where one and the other were combined. The housing is shown in a cross-sectional view as viewed in the direction of arrow B in FIG. It is a photograph of the principal part of a tubular structure. It is the graph which showed the relation between the depth of an annular crevice in the case of nominal diameter 80A, and the fracture limit of a remaining part. It is the graph which showed the relationship between the depth of the annular crevice in the case of nominal diameter 80A, and the elastic limit of the remaining part. It is the graph which showed the relationship between the depth of the annular crevice in the case of nominal diameter 80A, and the maximum detachment prevention load of a tubular structure. It is the graph which showed the breaking limit to the depth of annular crevice 12 in the case of nominal diameter 150A. It is the graph which showed the elastic limit to the depth of annular crevice 12 in the case of nominal diameter 150A. It is the graph which showed the maximum detachment prevention load to the annular crevice depth in the case of nominal diameter 150A. It is a typical fragmentary sectional view explaining a modification state of tubular member 1 or 1A when tensile force is added to tubular member 1 or 1A, (a) is a comparative form, and (b) is this embodiment.

First Embodiment
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings and the like.
FIG. 1 is a cross-sectional view showing a state in which two tubular structures 100 according to the present embodiment (100A, 100B), a sealing rubber 40 and a housing 30 are connected. Although the tubular structure 100 of the present embodiment is used for the fluid coupling portion, it is not limited thereto.

The tubular structure 100 according to the present embodiment includes the tubular member 1, the small diameter side fitting ring 13 </ b> A disposed on the outer periphery of the tubular member 1, and the large diameter side fitting ring 13 </ b> B.

The tubular member 1 is made of, for example, a steel pipe made of stainless steel (SUS304). The tubular member 1 has a small diameter portion 10 and a large diameter portion 20 provided continuously from one end of the small diameter portion 10.
The end of the small diameter portion 10 not connected to the large diameter portion 20 is an insertion port 11 connected to the large diameter portion 20 of the other tubular member 1. In the vicinity of the end portion of the insertion port 11, a small diameter side annular recess 12A is formed.
The end of the large diameter portion 20 not connected to the small diameter portion 10 is a socket 21 connected to the insertion port 11 of another tubular member 1. In the vicinity of the end portion of the receiving port 21, a large diameter side annular recess 12B is formed.

Next, the small diameter side annular concave portion 12A and the large diameter side annular concave portion 12B will be described, but in the following description, the small diameter side annular concave portion 12A provided near the end of the insertion port 11 and the vicinity of the end of the socket 21 The provided large-diameter-side annular recess 12B is the same as the annular recess 12B, except for the case where it is necessary to distinguish between the two.

FIG. 2 is a partial cross-sectional view of the tubular member 1 in a state in which the fitting ring 13 is not attached.
As shown, an annular recess 12 is formed on the outer surface of the tubular member 1 by cutting.
The width t1 of the annular recess 12 is 8 mm in the present embodiment.

In the present embodiment, a so-called normal schedule system 10 (Sch10) is used as the tubular member 1.

(Nominal diameter 80A)
For example, in the case of the nominal diameter 80A (actual diameter: φ89.1 mm), the thickness around the annular recess 12 (wall thickness in the state of the raw pipe of the tubular member 1, tube thickness) t3 is 3.0 mm. The remaining tube thickness of the annular recess 12 is preferably thicker than 1.0 mm in terms of strength. More preferably, the depth t2 (cutting depth) of the annular recess 12 is half or less of the tube thickness t3 in the tubular member 1, in which case the cutting depth is 1.0 to 1.5 mm, and the remaining tube thickness is It is 2.0 to 1.5 mm.

(Nominal diameter 150A)
For example, in the case of the nominal diameter 150A (actual diameter: φ 165.2 mm), the tube thickness t3 is 3.5 mm. The remaining tube thickness of the annular recess 12 is preferably thicker than 1.0 mm in terms of strength. More preferably, the cutting depth is 1.0 to 2.0 mm, and the remaining pipe thickness is 2.5 to 1.5 mm.

The small diameter side fitting ring 13A is inserted into the small diameter side annular recess 12A on the outer periphery of the small diameter portion 10. The large diameter side fitting ring 13 </ b> B is inserted into the large diameter side annular recess 12 </ b> B on the outer periphery of the large diameter portion 20.
Hereinafter, since the small diameter side fitting ring 13A inserted into the small diameter side annular recess 12A and the large diameter side fitting ring 13B inserted into the large diameter side annular recess 12B are the same except for the diameters, they need to be distinguished below. Except in the case where there are two, the two will not be distinguished and will be described as the fitting ring 13.

FIG. 3 is a partial cross-sectional view showing a state in which the fitting ring 13 is attached to the tubular member 1 in the state of FIG.
The fitting ring 13 is divided into two arc-shaped members. FIG. 4 is a view for explaining the fitting ring 13, wherein (a) is a perspective view of one arc-shaped member 13a divided into two, and (b) is a perspective view of the other arc-shaped member 13b divided into two. (C) shows a state in which the arc-shaped member 13a and the arc-shaped member 13b are joined.

The fitting ring 13 is manufactured, for example, by cutting a roughly shaped cast product. Therefore, the inset ring 13 can be manufactured with higher accuracy than when it is manufactured by casting.
Although the fitting ring 13 of this embodiment is divided into two, it is not limited to this and may be divided into three or more.
Bolt holes 13aa are formed at both ends of the arc-shaped member 13a.
Both end portions of the arc-shaped member 13b are cut away leaving a wall portion 13ba of a predetermined width, and the wall portion 13ba is provided with an insertion hole 13bb through which a bolt is inserted.

As shown in FIG. 4C, the insertion ring 13 has the end portions of the arc-shaped member 13a and the arc-shaped member 13b opposite to each other, and the bolt 14 is inserted from the insertion hole 13bb of the arc-shaped member 13b. It is integrally formed by screwing with the bolt hole 13aa of the arc-shaped member 13a.

The inner periphery of the fitting ring 13 in the coupled state is slightly shorter than the outer periphery of the annular recess 12 in which the fitting ring 13 is mounted. That is, the fitting ring 13 has an interference with the bottom (outer surface) of the annular recess 12.
When the arc-shaped member 13a and the arc-shaped member 13b are disposed on the outer periphery of the annular recess 12 and the bolt 14 is tightened by the tightening margin and the arc-shaped member 13a and the arc-shaped member 13b are connected to each other, the fitting ring 13 The pressure is fixed to the outer periphery of the annular recess 12.

The fitting ring 13 has two

side surfaces

13c and 13d parallel to each other along a plane perpendicular to the axis A of the tubular member 1 as shown in FIG. However, the side surfaces 13 c and 13 d may not be exactly perpendicular to the axis A.

The fitting ring 13 is a rectangular ring having a rectangular cross section, and in the present embodiment, the width T1 (the distance between the side surface 13c and the side surface 13d, the axial width and thickness of the tubular member 1) is an annular recess 12 In the present embodiment, the annular recess 12 is fitted to the annular recess 12 with no gap. Moreover, the protrusion height T3 which protrudes outside from the outer periphery of the tubular member 1 of the insertion ring 13 is 8 mm. That is, the radial thickness T2 of the fitting ring 13 is adjusted in accordance with the depth t2 of the annular recess 12.

The protruding height T3 of the fitting ring 13 protruding outward from the outer periphery of the tubular member 1 is the clearance between the inner peripheral surface of the housing 30 (the inner peripheral surface of the portion other than the groove) and the outer peripheral surface of the tubular member 1 3 mm or more larger than 2.5 mm which is the maximum value of T4 (shown in FIG. 1) is preferable.
The projection height T3 of the insertion ring 13 is preferably equal to or less than the distance T5 between the bottom of the grooves 36 and 38 (described later) provided in the housing 30 and the outer peripheral surface of the tubular member 1.
In the present embodiment, since the height T3 of the insertion ring 13 is 8 mm and the depth t2 (see FIG. 2) of the annular recess 12 is 1.5 mm, the projection height T2 is 9.5 mm.

The material of the fitting ring 13 is, for example, stainless steel (SUS 304). The material of the inset ring 13 is not limited to stainless steel, but the hardness of the inset ring 13 preferably has a hardness greater than that of the soft one of the housing 30 and the annular recess 12 or 22 (tubular member 1). .
If the fitting ring 13 is softer than the housing 30 and the annular recesses 12 and 22, the fitting ring 13 is plastically deformed when a force is applied in a direction in which the two

tubular structures

100A and 100B to be coupled are separated from each other. There is a possibility that the tube removal prevention performance can not be secured.

A sealing rubber 40 is attached to the outer periphery of the connection portion of the two tubular structures 100.
The sealing rubber 40 has two inner

peripheral surfaces

41 and 42 facing the outer peripheral surface of the tubular member 1 and has a substantially L shape in the cross section shown in FIG. However, it is not limited to this, and may be U-shaped, for example.
The diameter of one inner peripheral surface 41 is slightly smaller than the diameter of the outer peripheral surface of the small diameter portion 10, and when it is disposed on the outer peripheral surface of the small diameter portion 10, it elastically deforms and closely contacts the outer peripheral surface of the small diameter portion 10.
The other inner peripheral surface 42 is slightly smaller than the diameter of the outer peripheral surface of the large diameter portion 20, and when it is disposed on the outer peripheral surface of the large diameter portion, it elastically deforms and closely contacts the outer peripheral surface of the large diameter portion 20.

A housing 30 is attached to the outer peripheral side of the sealing rubber 40.
FIG. 5 shows the housing 30 in a cross-sectional view as viewed in the direction of arrow B in FIG.
The housing 30 is manufactured by the cast iron prescribed by JIS G 5502 FCD450 in this embodiment. Since the housing 30 is thus made of cast iron, the dimensional tolerance is larger than that of the fitting ring 13, and the maximum of the inner peripheral surface of the housing 30 (the portion where the groove is not provided) and the outer peripheral surface of the tubular member 1 is obtained. The clearance is about 2.5 mm as described above.

The housing 30 comprises two

semicircular members

30A, 30B as shown in FIG. The

semicircular members

30A and 30B each include a semicircular ring portion 31 along the outer periphery of the tubular member 1 and two flange portions 32 extending radially outward from both ends of the semicircular ring portion 31.
The flange portion 32 is provided with holes 33 respectively. When the

semicircular members

30A and 30B are disposed on the outer periphery of the tubular structure 100, and the flange portion 32 of the semicircular member 30A and the flange portion 32 of the semicircular member 30B face each other, the holes 33 provided in both flange portions 32. Penetrates.
A bolt 34 is inserted into the hole 33, and a nut 35 is screwed into the end of the threaded portion of the bolt 34. By tightening the nut 35, the two

semicircular members

30A, 30B cover the outer periphery of the tubular structure 100, and the two tubular structures 100 are connected.

As shown in FIG. 1, on the inner peripheral surface of the housing 30, an annular groove 36 covering the outer periphery of the large diameter side fitting ring 13B of the receiving port 21, an annular groove 37 fitting with the sealing rubber 40, and insertion An annular groove 38 is provided to cover the 11 small diameter side fitting rings 13A.
The width of the annular groove 36 has a slight gap so that the large diameter side fitting ring 13B can be inserted.
The width of the annular groove 38 is considerably larger than the width of the small diameter side fitting ring 13A. The reason is that, for example, according to the standard of JWWA G 113, since the tubular structure 100 needs to have an elasticity of about plus or minus 1.0% with respect to the pipe length, it absorbs the expansion and contraction thereof. is there.

(Method of manufacturing tubular structure)
The annular recess 12 is manufactured by cutting the outer periphery of the tubular member 1 in a state in which the annular recess 12 is not formed as shown in FIG.

Then, as shown in FIG. 4C, one arc-shaped member 13a and the other arc-shaped member 13b of the two-piece fitting ring 13 are disposed on the outer periphery of the annular recess 12 and mutually attached with the bolt 14 tighten. Thereby, the fitting ring 13 presses the outer surface of the tubular member 1, and as shown in FIG. 3, the fitting ring 13 is pressed and fixed to the annular recess 12 of the tubular member 1. FIG. 6 is a photograph of the main part of the tubular structure 100 in a state in which the fitting ring 13 is pressed and fixed in the annular recess 12 of the tubular member 1.

(Connection method of tubular structure)
The connection method of the tubular structure 100 will be described.
First, the sealing rubber 40 is inserted into the connecting side of the insertion port 11 or the receiving port 21 in one of the two tubular structures 100 to be connected.
Then, into the inside of the sealing rubber 40, the other of the two tubular structures 100, the connecting side of the insertion port 11 or the receiving port 21 is inserted.

The

semicircular members

30A, 30B of the housing 30 are disposed on the outer periphery of the tubular structure 100.
At this time, the small diameter side fitting ring 13A enters the annular groove 38, the sealing rubber 40 enters the annular groove 37, and the large diameter side fitting ring 13B enters the annular groove 36.
The flange portion 32 of the semicircular member 30A and the flange portion 32 of the semicircular member 30B are opposed to each other, the bolt 34 is inserted into the hole 33 provided in both flange portions 32, and the nut 35 is inserted into the tip of the screw portion of the bolt 34 Screw up.
By tightening the nut 35, the two

semicircular members

(Effect of tubular structure of the present embodiment)
The effects of the tubular structure 100 of the present embodiment will be described.
Table 1 shown below is a table showing the maximum separation preventing loads of the tubular structure 100 of the present embodiment and the tubular structure of the comparative embodiment.
Here, the maximum separation prevention load is achieved by fixing the socket and the socket with a housing, attaching a jig that can be chucked with a tensile tester at both pipe ends by welding, and performing a tensile test in the axial direction taking measurement. In the case of measuring the strength on the receiving side, the insertion ring 13 on the insertion side is welded, and in the case of measuring the strength on the insertion side, the insertion ring 13 on the receiving side is welded. That is, the side opposite to the side for measuring the maximum separation preventing load has a high strength separation preventing structure so that the side for measuring the maximum separation prevention load breaks first.

The results of this embodiment are shown in (1) to (3). Further, (4) to (6) are comparative embodiments, and (4) is obtained by welding a fitting ring to the outer periphery of the tubular member described in Patent Document 1 mentioned above. In (5), as described in the above-mentioned Patent Document 2, the retaining member is mounted on the outer periphery of the tubular structure, and the diameter of the retaining member is reduced by the cap nut having a tapered surface. The tube ends are joined together by biting into the outer periphery of the annular structure. In (6), as described in Patent Document 3 described above, the pipes are connected by inserting a lock ring, which is a retaining member, into a groove formed on the outer peripheral surface of the pipe.
As the tubular member, the nominal diameter 80A (actual diameter: φ89.1 mm, tube thickness: 3.0 mm) was used as described above.

As shown in Table 1, the largest separation prevention load is the largest in the comparative form (4). (4) is the fitting ring attached to the end of the pipe by welding.
Here, the tubular structure is adjusted in length at the construction site and cut. Then, since the pipe end position is determined at the construction site, the work of welding the fitting ring to the pipe end also needs to be performed at the construction site. However, processing at the construction site is not preferable in terms of quality assurance. Therefore, the comparison form of (4) is difficult to be practically implemented.

On the other hand, although the tubular structure of comparative form (5), (6) can be a node of the length in a construction site, this embodiment is compared with these (5), (6), The maximum separation prevention load is large and shows a value close to (4).

As described above, according to the present embodiment, the groove depth of the stainless steel pipe having a thickness of about 3.0 mm can be obtained by inserting the fitting ring 13 into the annular recess 12 with an interference. It is possible to provide a joint structure capable of obtaining an anti-disengagement ability (maximum anti-separation load) of 160 kN or more, which is twice the nominal diameter 80A and less than 3 times 240 kN, at 0 mm, 1.2 mm and 1.5 mm.
In addition, since welding is not used, for example, processing at a construction site using a hand grinder or the like is also possible.

As mentioned above, although 1st Embodiment of this invention was described, it is not limited to this. Although the tubular structure 100 according to the embodiment has been described in which the annular recess and the

fitting rings

13A and 13B are disposed on both sides of the insertion port 11 and the receiving port 21, the invention is not limited thereto. The annular recess and the

fitting rings

13A and 13B may be provided, and the

fitting rings

13A and 13B may be welded to the tubular member 1 without providing the annular recess in the receiving port.

Second Embodiment
Next, a second embodiment of the present invention will be described. The second embodiment is a tubular structure 100 applicable even when the required load required (breaking strength and maximum detachment prevention load) is large. Specifically, for example, the required load is 240 kN in the case of the nominal diameter 80A, and the tubular structure 100 applicable also in the case of the 450 kN in the case of the nominal diameter 150A.

The tubular structure 100 according to the first embodiment uses the tubular member 1 whose dimension system of piping thickness is the normal schedule system 10 (hereinafter referred to as Sch10), but the present embodiment is thicker than the Sch10, for example, the normal schedule The tubular member 1 of system 20 (hereinafter referred to as Sch 20) is used.

As shown in Table 2, in Sch20, for example, in the case of nominal diameter 80A (actual diameter: φ 89.1 mm), the tube thickness is 4.0 mm, and in the case of nominal diameter 150 A (actual diameter: φ 165.2 mm), the pipe The thickness is 5.0 mm. On the other hand, in the case of Sch10, for example, in the case of nominal diameter 80A (actual diameter: φ89.1 mm), the tube thickness is 3.0 mm, and in the case of nominal diameter 150A (actual diameter: φ165.2 mm), the tube thickness is 3 It is .5 mm.

In the present embodiment, the depth of the annular recess 12 is 1.45 mm to 2.45 mm for the nominal diameter 80A, and 1.4 mm to 3.4 mm for the nominal diameter 150A. The same reference numerals are given to the other similar components, and the description is omitted.

Table 3 below prepares the tubular member 1 of the present embodiment and the tubular member of the comparative embodiment for each of the two tube thicknesses of Sch10 and Sch20, and applies the present embodiment to the insertion side to break strength. And it is a table | surface which shows the result of having measured the largest detachment | leave load. The parts shown in bold in the table are this embodiment.
The elastic limit means the cross-sectional area of the remaining portion (indicated by reference numeral 12A in FIG. 2) remaining in the portion where the annular recess 12 of the tubular member 1 is formed × yield stress YS of the test piece (in the case of SUS304) 278 MPa), the breaking limit is the cross-sectional area of the remaining portion 12A × the tensile strength TS of the test piece (667 Mpa in the case of SUS304). Also, the gray parts are parts that do not satisfy the required load. FIG. 7-12 is a graph of a part of Table 3. An area indicated by an arrow in the drawing is an area in the present embodiment.

(Nominal diameter 80A)
FIG. 7 is a graph showing the relationship between the depth of the annular recess 12 and the fracture limit of the remaining portion 12A in the case of the nominal diameter 80A.
As shown in FIG. 7, in the case of the tubular member 1 having a nominal diameter of 80 A and a tube thickness of 3.0 mm (Sch10), the fracture limit is 240 kN or less when the depth of the annular recess 12 is 1.7 mm or more. , The required load 240kN of the second embodiment is not satisfied.
In the case of the tubular member 1 having a nominal diameter of 80 A and a tube thickness of 4.0 mm (Sch20), when the depth of the annular recess 12 is 2.7 mm or more, the breaking limit becomes 240 kN or less and the required load 240 kN of the second embodiment is satisfied. Absent.
On the other hand, the tubular member 1 having a nominal diameter of 80 A, a tube thickness of 4.0 mm (Sch20), and a depth of 1.45 mm to 2.45 mm of the annular recess 12 of the present embodiment satisfies the necessary load 240 kN.

FIG. 8 is a graph showing the relationship between the depth of the annular recess 12 and the elastic limit of the remaining portion 12A in the case of the nominal diameter 80A. As shown in FIG. 8, with respect to the elastic limit, the tubular member 1 having a nominal diameter of 80 A and a tube thickness of 4.0 mm (Sch20) is annular rather than the tubular member 1 having a nominal diameter of 80 A and a tube thickness of 3.0 mm (Sch10). It improves regardless of the depth of the recess 12.

FIG. 9 is a graph showing the relationship between the depth of the annular recess 12 and the maximum separation preventing load of the tubular member 1 in the case of the nominal diameter 80A. As shown in FIG. 9, with respect to the maximum separation preventing load, in the case of the tubular member 1 having a nominal diameter of 80 A and a tube thickness of 3.0 mm (Sch10), the maximum separation preventing load is 240 kN or less regardless of the depth of the annular recess 12 , The required load 240kN of the second embodiment is not satisfied.
In the case of the tubular member 1 having a nominal diameter of 80 A and a tube thickness of 4.0 mm (Sch20), when the depth of the annular recess 12 is smaller than 1.45 mm and larger than 2.45 mm, the maximum separation prevention load is 240 kN or less The required load 240 kN of the second embodiment is not satisfied.
On the other hand, the tubular member 1 having a nominal diameter of 80 A, a tube thickness of 4.0 mm (Sch20), and a depth of 1.45 mm to 2.45 mm of the annular recess 12 of the present embodiment satisfies the necessary load 240 kN.

(Nominal diameter 150A)
FIG. 10 is a graph showing the breaking limit of the remaining portion 12A with respect to the depth of the annular recess 12 in the case of the nominal diameter 150A.
As shown in FIG. 10, in the case of the tubular member 1 having a nominal diameter of 150 A and a tube thickness of 3.5 mm (Sch10), the fracture limit is 450 kN or less when the depth of the annular recess 12 is 2.2 mm or more. , Does not satisfy the required load of the second embodiment.
In the case of the tubular member 1 having a nominal diameter of 150 A and a tube thickness of 5.0 mm (Sch20), when the depth of the annular recess 12 is 3.6 mm or more, the breaking limit is 450 kN or less and the required load of the second embodiment is not satisfied. .
On the other hand, the tubular member 1 having a nominal diameter of 150 A, a tube thickness of 5.0 mm (Sch20), and a depth of 1.4 mm to 3.4 mm of the annular recess 12 of the present embodiment satisfies the required load 450 kN.

FIG. 11 is a graph showing the elastic limit of the remaining portion 12A with respect to the depth of the annular recess 12 in the case of the nominal diameter 150A. As shown in FIG. 11, with respect to the elastic limit, the tubular member 1 having a nominal diameter of 150 A and a tube thickness of 5.0 mm (Sch20) is annular rather than the tubular member 1 having a nominal diameter of 150 A and a tube thickness of 3.5 mm (Sch10). It improves regardless of the depth of the recess 12.

FIG. 12 is a graph showing the maximum separation preventing load with respect to the annular recess depth in the case of the nominal diameter 150A. As shown in FIG. 12, in the case of the tubular member 1 having a nominal diameter of 150 A and a tube thickness of 3.5 mm (Sch10), the maximum detachment preventing load is 450 kN or less of the required load regardless of the depth of the annular recess 12 The required load of 2 embodiment is not satisfied.
In the case of the tubular member 1 having a nominal diameter of 150 A and a tube thickness of 5.0 mm (Sch20), when the depth of the annular recess 12 is smaller than 1.4 mm and larger than 3.4 mm, the maximum separation prevention load becomes 450 kN or less The required load of the second embodiment is not satisfied.
On the other hand, the tubular member 1 having a nominal diameter of 150 A, a tube thickness of 5.0 mm (Sch20), and a depth of 1.4 mm to 3.4 mm of the annular recess 12 of the present embodiment satisfies the required load 450 kN.

FIG. 13 is a schematic partial cross-sectional view for explaining a deformed state of the tubular members 1 and 1A when a tensile force is applied to the tubular members 1 and 1A, wherein (a) is a comparative embodiment and (b) is the present embodiment. It is a form. The tube thickness of the tubular member 1A of the comparative form is thinner than the tube thickness of the tubular member 1 of the present embodiment.
In the case of the comparative embodiment, when a tensile force is applied to the tubular member 1A in the longitudinal direction, the tubular member 1A tends to extend in the longitudinal direction because the tube thickness is thin. Therefore, the tubular member 1A has a large radial contraction. For this reason, since the diameter of the tubular member 1A is contracted, the fitting with the fitting ring 13 becomes shallow or no fitting as shown in the drawing, and the maximum separation preventing load is reduced.
On the other hand, as in the present embodiment, when the tube thickness of the tubular member 1 is large, the degree of extension of the tubular member 1 in the longitudinal direction when the tensile force is applied to the tubular member 1 in comparison with the comparative embodiment Small and radial contraction is also small. Therefore, the amount of decrease in the fitting with the fitting ring 13 is small, and the maximum separation preventing load is large as compared with the comparative embodiment.
Therefore, according to the tubular member 1 having a nominal diameter of 80A, a tube thickness of 4.0 mm (Sch20) and a depth of 1.45 mm to 2.45 mm of the annular recess 12 of the present embodiment, the required load 240 kN can be satisfied. Further, according to the tubular member 1 having a nominal diameter of 150 A, a tube thickness of 5.0 mm (Sch20), and a depth of 1.4 mm to 3.4 mm of the annular recess 12 of the present embodiment, the required load 450 kN can be satisfied.
As described above, according to the present embodiment, in addition to the effects of the first embodiment, by using a thick tube as the raw tube of the tubular member 1, the elastic limit of the tube itself is improved. Bondability can be maintained, and high separation prevention performance can be obtained even at the same groove depth.

DESCRIPTION OF SYMBOLS 1 Tubular member 10 small diameter part 11 insertion 12 annular concave 12A small diameter side annular concave 12B large diameter side annular concave 13 fitting ring 13c side 13d side 13A small diameter side fitting ring 13B large diameter side fitting ring 30 housing 36 annular groove 37 Annular groove 38 Annular groove 40 Sealing rubber 41 Inner circumferential surface 42 Inner circumferential surface 100 Tubular structure

Claims

A tubular member having an annular recess formed at the end of the tube;
A fitting ring having two outer side surfaces perpendicular to the axis of the tubular member and pressed and fixed to the outer periphery of the annular recess;
Tubular structure comprising:
The fitting ring is divided into a plurality of arc-shaped members, and the arc-shaped members are connected to each other by a connecting member.
The inner periphery of the fitting ring in the coupled state is shorter than the outer periphery of the annular recess to which the fitting ring is pressed and fixed,
The tubular member is pressed and fixed to the outer periphery of the annular recess by disposing the arcuate member before connection on the outer periphery of the annular recess of the tubular member and connecting the arc-like members to each other by the connecting member.
A tubular structure according to claim 1.
The annular recess has two inner side surfaces perpendicular to the axis and a bottom surface parallel to the axis,
The fitting ring is a square ring,
The two inner side surfaces of the annular recess and the two outer side surfaces of the fitting ring are substantially in contact with each other, and the bottom surface of the annular recess is in contact with the inner peripheral surface of the fitting ring.
The tubular structure according to claim 1 or 2.
The depth of the annular recess is less than or equal to half the radial thickness of the tubular member,
The tubular structure according to any one of claims 1 to 3.
One of the tube ends of the tubular member is an inlet, and the other is a socket having a larger diameter than the inlet,
The annular recess and the fitting ring are provided on at least one side of the insertion port or the receiving port.
The tubular structure according to any one of claims 1 to 4.
The tubular member and the fitting ring are formed of stainless steel,
The tubular structure according to any one of claims 1 to 5.