JP4301973B2 - Tube connection structure and connection method - Google Patents

Description

  The present invention relates to a connection structure and a connection method for two tubular bodies having different diameters, in particular.

  Support pillars used for various purposes such as lighting for stadiums, mounting antennas, ballproof nets for golf courses, and power lines are required to have a certain length. Due to restrictions and the like, a connection (joint) assembled steel pipe in which a plurality of pipe bodies (particularly steel pipes) having different diameters are usually connected (joint) is used for these applications.

  Of the structures for connecting two steel pipes having different diameters, as conventional techniques in which connecting flanges fixed to each steel pipe are fastened and connected to each other, as described below, first to third conventional techniques are mainly used. There is technology.

The first prior art will be described with reference to FIG.
In FIG. 1, the first prior art includes a first connection flange 220 fixed to a connection side end of a large-diameter steel pipe main body 210 of a large-diameter steel pipe 200 serving as a foundation, and a small-diameter steel pipe of an extension small-diameter steel pipe 100. The second connecting flange 120 fixed to the connection side end of the main body 110 is abutted, and the fastening bolt 1 is inserted through the respective through holes 220a and 120a in common and fastened by the nut 2 through the washer 3. The reinforcing ribs 230 and 130 reinforce the fixing of the flanges 220 and 120 to the steel pipes 200 and 100, respectively. The first flange 220 is provided with a central through hole 220b for weight reduction and cost reduction (see, for example, Non-Patent Document 1).

  Here, the reason why the bolt 1 is inserted into the through holes 120a and 220a from the lower surface side rather than from the upper surface side of both flanges 120 and 220 is that the nut 2 is tightened not from the lower surface side of both flanges 120 and 220 but from the upper surface side. This is because the tightening work such as tool setting can be performed efficiently.

  According to the first prior art, in order to realize the insertion and tightening operation of the fastening bolt 1, the bolt 1 must be disposed further radially outward than the outer diameter of the large-diameter steel pipe 200. The diameter of the flange 220 is made larger than the diameter of the large-diameter steel pipe body 210, and the positions of the through holes 220a and 120a (that is, the bolts 1 and nuts 2) are arranged radially outward from the outer diameter of the large-diameter steel pipe body 210, respectively. It is necessary to arrange in this direction.

  Therefore, the connection structure of the steel pipes 200 and 100 has a problem that the material cost becomes high because the diameters of both the flanges 220 and 120 need to be larger than the outer diameter of the large-diameter steel pipe 200. Moreover, since both the flanges 220 and 120 protrude radially outward from the large-diameter steel pipe 200, there is a problem of deteriorating the aesthetic appearance. Furthermore, when this connection structure is used, for example, for supporting a ball-proof net, there is a problem that both flanges 220 and 120 protruding locally in the radial direction from the outer peripheral surface of the large-diameter steel pipe main body 210 damage the net.

Next, the second prior art will be described with reference to FIG.
In FIG. 2, the second conventional technique is generally the same as the first conventional technique except for the method of attaching the first connecting flange 320 to the large-diameter steel pipe 300. 2, the same parts as those in FIG. 1 are denoted by the same reference numerals and the description thereof is omitted, and “300” is used instead of the reference numeral “200” in FIG. This is indicated by adding “'” to the reference numeral.

  That is, a flange 350 having the same outer diameter is welded and fixed to the upper end of the large-diameter steel pipe body 310 on the connection side, and an intermediate steel pipe 340 having the same outer diameter as the small-diameter steel pipe body 310 is welded and fixed on the flange 350. A first flange 320 having the same outer diameter as that of the lower flange 350 is fixedly welded to the upper end of the steel pipe 340. A second flange 120 ′ having the same outer diameter as that of the flange 320 is connected to the first flange 320 of the intermediate steel pipe 340 in a butted state.

  At this time, as described above, in consideration of the operation efficiency of the tightening tool, the bolt 1 is commonly inserted from the lower end side of the first flange 320 of the intermediate steel pipe 340 into the through holes 320a and 120a ′ of both flanges 320 and 120 ′. It becomes possible to do. The reinforcing rib 360 is on the inner periphery of the large-diameter steel pipe 310 to reinforce the connection of the flange 350, and the reinforcing rib 330 is on the outer periphery of the intermediate steel pipe 340 to reinforce the connection of the flange 320.

  According to the second prior art, the diameters of both flanges 320 and 120 ′ that are abutted are substantially the same as the diameter of the large-diameter steel pipe main body 310 and do not protrude in the radial direction. In this case, the problem that both flanges 320 and 120 'damage the net is eliminated.

  However, even when the second prior art is used, the structure is complicated compared to the first prior art, so that the manufacturing cost increases and the reinforcing rib 330 is exposed. The problem of high costs and aesthetic problems cannot be solved.

  Unlike the second prior art (see FIG. 2), in order to solve the above-mentioned problem of damaging the net and at the same time solve all of the problems of high costs and aesthetic problems, The first connecting flange 320 having the same outer diameter as that of the large-diameter steel pipe main body 310 needs to be directly fixed without using the intermediate steel pipe 340 or the like.

Therefore, the present applicant has developed and commercialized a third conventional technique in which a connecting flange having the same outer diameter as that of the large-diameter steel pipe body is directly fixed to the large-diameter steel pipe.
This third prior art will be described with reference to FIG.

  In FIG. 3, the third prior art generally includes directly fixing the first connecting flange 320 ′ to the large-diameter steel pipe 300 ′ and the bolt 1 to each through hole 120 a ′ and 320 a ′ of both flanges. Except for the insertion direction, this is the same as the second prior art (see FIG. 2). In FIG. 3, the same parts as those in FIG. 2 are denoted by the same reference numerals, the description thereof is omitted, and the corresponding parts are indicated by adding “′” to the reference numerals in FIG.

  That is, the first flange 320 'having the same outer diameter is directly welded and fixed to the upper end of the large-diameter steel pipe body 310' on the connection side. The second flange 120 'welded and fixed to the lower end of the small diameter steel pipe 100' on the connection side has the same outer diameter as the first flange 320 '. The reinforcing rib 330 ′ is on the inner periphery of the large diameter steel pipe 300 ′ and reinforces the connection of the flange 320 ′.

Here, in the case of the third prior art, after the both flanges 320 ′ and 120 ′ are brought into contact with each other, the connecting operator cannot insert his / her hand into the large-diameter steel pipe body 310 ′. The bolt 1 cannot be disposed in the large-diameter steel pipe and tightened. Therefore, in this case, unlike the first and second prior arts described above, it is necessary to insert the bolt 1 through the through holes 120a ′ and 320a ′ from the upper surface side of both flanges 120 ′ and 320 ′. Therefore, each nut 2 is accurately positioned concentrically with each through-hole 320a ′ on the lower surface of the first flange 320 ′ inside the large-diameter steel pipe body 310 ′, and is welded and fixed in advance.
Edited by the Architectural Institute of Japan, “Guideline for Construction and Construction of Steel Pipes and Explanation” The Architectural Institute of Japan, December 25, 1998 (2nd edition, fifth print), p. 110-111

  However, the present applicant actually commercializes this third prior art, and positions and welds all (all eight in FIG. 3) nuts 2 to the first flange 320 ′ with high accuracy. It was difficult to find and the steel pipe connection work efficiency was significantly reduced.

  That is, in an actual product, not all nuts 2 are accurately positioned and welded, and therefore, all bolts 1 cannot be screwed into the corresponding nuts 2 and tightened at the connection work site. Often has to be repositioned and welded, and the steel pipe connection work efficiency is significantly reduced (when the diameter of the large diameter steel pipe 300 'increases and the number of nuts 2 is large (for example, 18)). In particular, this reduction in work efficiency is significant).

  Further, in the case of the third prior art, when the nut 2 is welded and fixed to the first flange 320 ′, the nut 2 becomes high temperature, so that the material of the nut 2 is altered and the strength of the steel pipe connection structure is increased. There is a problem that can be reduced. Further, when the bolt 1 is tightened, it is necessary to directly rotate and tighten the bolt 1, so that there is a problem that the bolt head 1 a may be damaged.

  Accordingly, an object of the present invention is to solve the problem of damage to the net, the problem of high cost, and the problem of impairing the aesthetics, and at the same time, the problem of lowering the connection efficiency of the steel pipe.

  In order to solve the above problems, the tubular body connection structure of the present invention is the first tubular body (400; 400 ′) in which the first connecting flange member (420) is fixed to the connection side end (410a). 400 ″) and a second connecting flange member (120 ′) fixed to the connection side end (110b ′) and smaller than the first tube (400; 400 ′; 400 ″) Each of the flange members (420, 120 ′) in a state where the first and second flange members (420, 120 ′) are abutted with each other. The through holes (420a, 120a ') are fastened and connected by the fastening members (1) that are commonly inserted, and the through holes (420a, 120a') of the flange members (420, 120 ') are connected in the radial direction. The arrangement is the first tube (400 400 ′; 400 ″) and a diameter (B) of the second tube (100 ′), the first tube (400; 400 ′; 400 ″) ) At a position inward of the first flange member (420) and a fastening member holding member (positioned and held in advance in a state substantially corresponding to the through hole (420a)). 440, 440 ′, 440 ″), and when the first and second flange members (420, 120 ′) are abutted, opposite to the abutting side of the second flange member (120 ′) The fastening is enabled by moving the fastening member (1) to the common insertion position by an operation from the side.

  Preferably, the fastening member holding member (440, 440 ′, 440 ″) is configured so that the fastening member (1) has a distal end portion (1b) at the first flange when the fastening member (1) is positioned in advance. A state is set in which the first predetermined amount (P1; P2) is inserted into the through hole (420a) of the member (420).

  Preferably, the fastening member holding member (440, 440 ′, 440 ″) has the fastening member (1) at the tip end (1b) of the first fastening member (1) in the first positioning state. The flange member (420) is set to a position that penetrates the through hole (420a) and protrudes by a second predetermined amount (Q).

  Preferably, the fastening member holding member (440; 400 ′; 400 ″) can variably set the axial relative position of the fastening member (1) with respect to the through hole of the first flange member (420). .

  Preferably, the fastening member holding member (440) includes a frame member (441) fixed to at least one of the first tube body (400) and the first flange member (420), and the fastening member. A holder member (442) that holds (1) and is attached to the frame member (441) so as to be adjustable in the axial direction of the through hole (420a) of the first flange member (420). It comprises.

  Preferably, the fastening member holding member (440 ″) is fixed to at least one of the first tube body (400 ″) and the first flange member (420), and the fastening member (1). A tubular connecting structure comprising a bottomed cylindrical body (446) capable of accommodating and holding a tube.

  Preferably, at least one of the bottomed cylindrical bodies (446) includes an elastic body (447) in the cylinder, whereby the elastic body (447) in the pre-positioned state of the fastening member (1). 447) biases the fastening member (1), and the distal end portion (1b) of the fastening member (1) passes through the through hole (420a) of the first flange member (420) and is second. The tube connecting structure is characterized in that it is set at a position protruding by a predetermined amount (Q).

  The pipe connecting method for solving the above-described problem is the first pipe (400; 400 ′; 400 ″) in which the first connecting flange member (420) is fixed to the connection side end (410a). And a second connecting flange member (120 ′) fixed to the connection side end (110b ′) and having a diameter smaller than that of the first tubular body (400; 400 ′; 400 ″). The pipe body (100 ′) and the first and second flange members (420, 120 ′) face each other, and the through holes (420a, 120a) of the flange members (420, 120 ′). ') Is fastened by a fastening member (1) that is inserted in common, and the radial arrangement of each through hole (420a, 120a') of each flange member (420, 120 ') is the first tubular body (400). 400 ′; 400 ″) diameter (A Positioning between the first tube (400; 400 ′; 400 ″) and the first tube (400; 400 ′; 400 ″). Fastening member holding members (440, 440 ′, 440 ″) that pre-position and hold the fastening member (1) in a state substantially corresponding to the through hole (420a) at a position near the flange member (420). The fastening member is provided by a step of abutting the first and second flange members (420, 120 ') and an operation from the opposite side of the abutting side of the second flange member (120'). And (1) moving to the common insertion position and fastening the first and second flange members (420, 120 ′).

  The basic tube body that solves the above problem is a basic tube body (400; 400 ′; 400 ″) in which the first connecting flange member (420) is fixed to the connection side end portion (410a). An extension small-diameter tube (100) having a second connecting flange member (120 ′) fixed to the connection-side end (110b ′) and having a smaller diameter than the basic tube (400; 400 ′; 400 ″). ') Is inserted through the through holes (420a, 120a') of the flange members (420, 120 ') in a state where the first and second flange members (420, 120') are abutted with each other. The flanges (420, 120 ′) are connected by being fastened by the fastening members (1), and the radial arrangement of the through holes (420a, 120a ′) of the flange members (420, 120 ′) is the basic pipe body (400; 400). '; 40 '') And a diameter (B) of the extending small diameter tube (100 '), and inward of the basic tube (400; 400'; 400 ''). In addition, fastening member holding members (440, 440 ', which can be positioned and held in advance in a state where the fastening member (1) is positioned substantially corresponding to the through hole (420a) at a position near the first flange member (420). 440 ″), and when the first and second flange members (420, 120 ′) are abutted, by operation from the opposite side of the abutting side of the second flange member (120 ′) The fastening member (1) can be fastened by moving it to the common insertion position.

  According to the tubular body connection structure of the present invention, the radial arrangement of each through hole of each flange member is positioned at a predetermined position, and is an inward position of the first tubular body and a position in the vicinity of the first flange member. A fastening member holding member that positions and holds the fastening member in a state substantially corresponding to the through hole in advance, and when the first and second flange members are abutted, what is the abutting side of the second flange member? Since the fastening can be performed by moving the fastening member to the common insertion position by an operation from the opposite side, the following advantages are obtained.

  (1) Since the structure of the pipe connection structure is simple and the material cost of the first and second flange members can be reduced, the manufacturing cost of the pipe connection structure can be reduced. Since the first and second flange members do not protrude in the radial direction from the outer peripheral surface of the first tubular body, and the reinforcing ribs of the first tubular body are not exposed, the aesthetics are improved as compared with the prior art. Will not be damaged. In addition, for example, when the connection structure of the main body is used for supporting a ball-proof net such as a golf course, the problem of damaging the net can be solved. Furthermore, since the fastening member is positioned and held in advance at the inward position of the first tubular body, there is a risk that the connection work efficiency of the tubular body may be reduced due to re-tightening of the fastening member as in the third prior art. Absent.

  (2) Since the fastening member holding member sets the fastening member in a state where the front end portion thereof is inserted into the through hole of the first flange member by the first predetermined amount in the positioning state of the fastening member in advance, In the positioning state in advance, the wobbling of the fastening bolt can be reduced.

  (3) Since the fastening member holding member is set in a position where the fastening member is positioned in advance, the tip of the fastening member protrudes through the through hole of the first flange member and protrudes by a second predetermined amount. When the second flange member is abutted against the first flange member, the second flange member can be positioned with respect to the first flange member by using the protruding fastening member as a guide.

  (4) Since the fastening member holding member can variably set the axial relative position of the fastening member with respect to the through hole of the first flange member, the first and second predetermined amounts can be adjusted, and work efficiency can be improved. It can improve.

(5) Since the fastening member holding member includes the predetermined frame member and the holder member, the structure for variable position setting of the fastening member can be simplified.
(6) Since the fastening member holding member includes a bottomed cylindrical body capable of accommodating and holding the fastening member, the structure can be simplified.

  (7) Since at least one of the bottomed cylindrical bodies includes an elastic body that realizes the second predetermined amount of protrusion of the fastening member in the cylinder, the protruding fastening member is used as a guide. When the second flange member is butted against the first flange member, if the positioning of the second flange member fails and the distal end portion of the fastening member is not inserted into the through hole, the fastening member is Since it is suppressed by the member and can move downward against the urging force of the elastic body, the operation of inserting the fastening member into the through hole of the second flange member is facilitated, and the fastening member is The possibility of damaging the two flange members can be reduced.

A first embodiment of a pipe connection structure according to the present invention will be described with reference to FIGS.
5 and 6, a large-diameter steel pipe 400 serving as a foundation as the first pipe body is generally composed of a steel pipe body 410 having a predetermined outer diameter A, and is connected to the connection side end 410 a in the circumferential direction in FIG. A first connection flange 420 having, for example, eight through holes 420a and a central through hole 420b at equal positions is fixed. The reinforcing rib 430 is positioned at a substantially equally divided position in the inner circumferential direction of the large-diameter steel pipe main body 410 and is fixed to the first flange 420 and the large-diameter steel pipe main body 410. The steel fastening bolt 1 as the fastening member may be other fastening means such as a pin (not shown) fastened by a split pin, for example. The outer diameter of the first connecting flange 420 is preferably substantially equal to the outer diameter A of the large-diameter steel pipe body 410.

  4 and 6, the extended small-diameter steel pipe 400 as the second pipe body is generally a small-diameter steel pipe body 110 ′ having a predetermined outer diameter B (A ′> B) smaller than the inner diameter A ′ of the large-diameter steel pipe body 410. A second connection flange 120 ′ having a central through hole 120b ′ is fixed to the connection side end 110b ′ in the lower part of FIG. The outer diameter of the second connecting flange 120 ′ is preferably substantially equal to the outer diameter A of the large diameter steel pipe body 410.

  The first and second flanges 420 and 120 'are respectively positioned in the radial direction between the inner diameter A' of the large-diameter steel pipe 400 and the outer diameter B of the small-diameter steel pipe 100 ', and corresponding through holes 420a. And 120a ′. The large diameter steel pipe 400 and the small diameter steel pipe 100 ′ may be made of a material other than steel.

  5 and 6, a fastening bolt holding member 440 as a fastening member holding member is roughly a ring-shaped frame 441 and, for example, eight holder members arranged at circumferentially equal positions of the ring-shaped frame 441. The holder 442 includes a support bolt 443, a double nut 445, and a bottomed cylindrical shape that can be attached to the upper ends of the support bolt 443 and can accommodate and hold the fastening bolts 1 (in this case, a total of eight). Part 444.

  The ring-shaped frame 441 is welded to at least one of the large-diameter steel pipe main body 410 and the reinforcing rib 430 at a position that is inward of the large-diameter steel pipe main body 410 and is relatively close to the first flange 420 by a predetermined distance. It is fixed.

  The support bolt 443 is inserted into the through hole 441 a of the frame 441 and fastened to the frame 441 by a double nut 445. The through hole 441a is arranged so that the axial direction of the fastening bolt 1 accommodated and held in the bottomed tubular portion 444 substantially coincides with the axial direction of the through hole 420a of the first flange 420.

  The holder 442 (support bolt 443, bottomed cylindrical portion 444) can be adjusted and moved in the axial direction by adjusting the double nut 445. The holder 442 may not include the bottomed cylindrical portion 444, and the support bolt 443 may directly support the bolt head 1a of the fastening bolt 1 (not shown).

Next, the connection procedure of the large diameter steel pipe 400 and the small diameter steel pipe 100 ′ will be described.
The bolt head 1a of the fastening bolt 1 is inserted and disposed in the bottomed cylindrical portion 444 of the holder 442 in a state where the holder 442 is moved and adjusted further downward than the position of FIG. Thereafter, the double nut 445 is adjusted, and each support bolt 443 is adjusted and moved upward in the figure, so that, for example, the front end portions 1b of the four fastening bolts 1 at the circumferentially equal position are penetrated by the first flange 420. For example, the first predetermined amount P1 (see FIG. 5) that is slightly sunk from the upper end of the hole 420a is inserted into the hole 420a, and the tip portions 1b of the remaining four fastening bolts 1 pass through the through hole 420a. Then, it is previously positioned at a position protruding by the second predetermined amount Q (see FIGS. 5 and 6). By inserting the tip 1b of the fastening bolt 1 into the through hole 420a by at least the first predetermined amount P1, there is an effect of preventing the fastening bolt 1 from wobbling.

  Subsequently, the second flange 120 ′ of the small-diameter steel pipe 100 ′ is inserted into each through hole 120a ′ of the second flange 120 ′ with respect to the first flange 420 so that the tip end portion 1b of the fastening bolt 1 is inserted. Position and abut (see FIGS. 6 and 7).

  Subsequently, as shown in FIG. 7, the fastening bolt 1 is attracted by the bar magnet 480 from the side opposite to the butting side of the second flange 100 ′ (that is, the upper side in the figure), and in the direction of the arrow in the figure. The lifting operation is performed so that the tip 1b of the fastening bolt 1 penetrates the second flange 120 'and protrudes by a predetermined amount. After that, as shown in FIG. 8, the fastening bolt 1 is fastened by the nut 2 through the washer 3, and the first and second flanges 420 and 120 ′ are fastened. Thus, the small diameter steel pipe 100 ′ is replaced with the large diameter steel pipe 400. Connect to.

  Note that the fastening bolt 1 may not be inserted into the through holes 420a and 100a 'in the pre-positioned state.

A second embodiment of the tube connection structure according to the present invention will be described with reference to FIG.
In FIG. 9, the connection structure of the first and second tubular bodies as the second embodiment is roughly the frame 440 ′ as the fastening member holding member, and the fastening bolt holding member 440 of the first embodiment shown in FIG. Instead of (frame 441, holder 442), it is used. In FIG. 9, the same parts as those in FIG. 6 are denoted by the same reference numerals, and the description thereof is omitted.

  The frame 440 ′ has substantially the same shape as the frame 441 in FIG. 6, but has a ring-shaped protrusion 440a ′ (diameter d) in the circumferential direction of the upper surface thereof, for example, at eight equal positions. And is welded to the vicinity of the first flange 420. Each fastening bolt 1 has a lower bolt head 1 a inserted into the ring-shaped protrusion 440 a ′ and an upper bolt tip 1 b inserted into the through hole 420 a of the first flange 420 by a predetermined distance P 2. Positioned. The frame 440 ′ is fixed to the first flange 420 via, for example, a reinforcing rib 430.

  The fastening bolt 1 may be inserted into the through hole 120a ′ by an operation using a bar magnet (not shown) as in the first embodiment, or as shown in FIG. For example, a strip-like member 490, such as a string previously connected to 1, may be used to perform the above-described common insertion by performing a pulling operation in the direction of the arrow in the figure.

  The subsequent connecting procedure of the large-diameter steel pipe 400 'and the small-diameter steel pipe 100' is substantially the same as that in the first embodiment.

A third embodiment of the pipe connection structure according to the present invention will be described with reference to FIG.
In FIG. 10, the connection structure of the first and second tubular bodies as the third embodiment is roughly the fastening bolt holding member 440 ″ as the fastening member holding member is the fastening of the first embodiment shown in FIG. It replaces with the bolt holding member 440 and is used. In FIG. 10, the same parts as those in FIG. 6 are denoted by the same reference numerals, and the description thereof is omitted.

  The fastening bolt holding member 440 '' includes eight bottomed tubular bodies 446 that are welded and fixed to the lower surface of the first flange 420 at the inner side of the large-diameter steel pipe body 410 at positions substantially concentric with the through holes 420a, It consists of a spring 447 as an elastic body housed in a bottomed cylindrical body 446.

  The bottomed tubular body 446 accommodates the fastening bolt 1 in advance and is fixed to the lower surface of the first flange 420. At this time, the fastening bolt 1 is urged by a spring 447, and the tip 1b thereof is the first. A second predetermined amount Q protrudes upward in the drawing through the through hole 420a of the flange 420.

  Next, when the second flange 120 ′ of the small-diameter steel pipe 100 ′ is butted against the first flange 420 and the protrusion of the fastening bolt 1 is inserted into the through hole 120a ′ of the second flange 120 ′, the bolt protrusion The part serves as a guide for flange alignment. At this time, if the positioning of the second flange 120 ′ fails and the front end portion 1 b of the fastening bolt 1 is not inserted into the through hole 120 a ′, the fastening bolt 1 is lowered downward against the biasing force of the spring 447. Therefore, the fastening bolt 1 and the second flange 120 ′ are not damaged.

The procedure for connecting the large diameter steel pipe 400 ″ and the small diameter steel pipe 100 ′ is substantially the same as that in the first embodiment.
The spring 447 inside each cylindrical body 446 may be another elastic body such as an elastic sponge.

It is a disassembled perspective view for showing the 1st prior art of the connection structure of a pipe. (Prior art 1) It is a disassembled perspective view for showing the 2nd prior art of the connection structure of a tubular body. (Prior art 2) It is a disassembled perspective view for showing the 3rd prior art of the connection structure of a tubular body. (Prior art 3) BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of a tube connection structure for explaining one embodiment of a tube connection structure and a connection method of the present invention. Example 1 FIG. 5 is a perspective view of a first tube body in FIG. 4. Example 1 It is sectional drawing which follows the II line | wire in FIG. Example 1 In FIG. 6, it is the figure which faced the 1st and 2nd flange. Example 1 In FIG. 7, it is the figure which fastened the 1st and 2nd flange with the fastening member. Example 1 It is an exploded sectional view of the connection structure of a tube for explaining the 2nd example of the connection structure and connection method of a tube of the present invention. (Example 2) FIG. 5 is an exploded cross-sectional view of a tube connection structure for explaining a third embodiment of the tube connection structure and connection method of the present invention. (Example 3)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fastening bolt 100,100 'Extension small diameter steel pipe 120,120' 2nd connection flange 400 Base steel pipe 420 1st connection flange 440,440 ', 440''Fastening bolt holding member

Claims (5)

A first tubular body (400; 400 ′; 400 ″) having a first connecting flange member (420) fixed to the connection side end portion (410a), and a second pipe end on the connection side end portion (110b ′). And a second tubular body (100 ′) having a diameter smaller than that of the first tubular body (400; 400 ′; 400 ″). Fastening members (1) that are inserted through the through holes (420a, 120a ′) of the flange members (420, 120 ′) in a state where the first and second flange members (420, 120 ′) are abutted with each other. In the tube connection structure that is fastened and connected by
The radial arrangement of each through hole (420a, 120a ′) of each flange member (420, 120 ′) is such that the diameter (A) of the first tube body (400; 400 ′; 400 ″) Positioned between the diameter (B) of the second tube (100 ′),
The fastening member (1) is inserted into the through hole (420a) at an inner position of the first pipe body (400; 400 ′; 400 ″) and at a position near the first flange member (420). A fastening member holding member (440, 440 ′, 440 ″) that is positioned and held in advance in a substantially corresponding position is provided,
When the first and second flange members (420, 120 ′) are abutted, the fastening member (1) is operated by an operation from the opposite side of the abutting side of the second flange member (120 ′). Can be fastened by moving to the common insertion position ,
The fastening member holding member (440; 400 ′; 400 ″) can variably set the axial relative position of the fastening member (1) with respect to the through hole of the first flange member (420),
The fastening member holding member (440) includes a frame member (441) fixed to at least one of the first tube body (400) and the first flange member (420), and the fastening member (1). And a holder member (442) attached to the frame member (441) so as to be adjustable and movable in the axial direction of the through hole (420a) of the first flange member (420). A tube connection structure characterized by the following.   2. The tube connection structure according to claim 1, wherein the fastening member holding member (440, 440 ′, 440 ″) is configured so that the fastening member (1) is positioned at a tip of the fastening member (1) in a pre-positioned state. A connecting structure for a tubular body, wherein the portion (1b) is set in a state of being inserted by a first predetermined amount (P1; P2) into the through hole (420a) of the first flange member (420).   3. The tubular body connection structure according to claim 1, wherein the fastening member holding member (440, 440 ′, 440 ″) is the fastening member (1) in a pre-positioned state of the fastening member (1). Of the tubular body characterized in that the tip portion (1b) passes through the through hole (420a) of the first flange member (420) and protrudes by a second predetermined amount (Q). Connection structure. 2. The tubular body connection structure according to claim 1, wherein the fastening member holding member (440 ″) is attached to at least one of the first tubular body (400 ″) and the first flange member (420). A tubular connection structure comprising a bottomed cylindrical body ( 444, 446) that is fixed and capable of accommodating and holding the fastening member (1). 5. The tube connection structure according to claim 4 , wherein at least one of the bottomed cylindrical bodies (446) includes an elastic body (447) in the cylinder, whereby the fastening member (1) In a pre-positioned state, the elastic body (447) urges the fastening member (1), and the fastening member (1) has a tip end (1b) through-hole of the first flange member (420). A connecting structure for tubular bodies, characterized in that it is set at a position penetrating (420a) and projecting by a second predetermined amount (Q).

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