JP3797534B2 - Tube connection structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a connection structure in which a pair of pipe bodies having an annular outer peripheral groove on an outer peripheral surface of an end portion are connected by a pipe joint , and more particularly to improvement of the groove shape of the outer peripheral groove.
[0002]
[Prior art]
Conventionally, as a method of connecting the tube bodies, a connecting structure as shown in FIG. 10 has been adopted in addition to a method of projecting flange portions at the end portions and fastening both flange portions with bolts in the tube axis direction. .
[0003]
In the connecting structure of FIG. 10, an annular seal member 54 is externally attached to the connecting portion P of both pipes 50, 50, and a cylindrical pipe joint 53 is externally attached to the outside of the annular seal member 54. In this structure, the connecting portion P is sealed from the outside by the member 54 and the pipe bodies 50 and 50 are connected by the pipe joint 53. Both pipes 50, 50 have outer peripheral grooves 52 formed on the outer peripheral surface 51 of the end, and annular inner projections 58, 58 projecting toward the center at both ends of the pipe joint 53, and are connected to each other. When the annular inner protrusions 58 are fitted in the respective outer circumferential grooves 52, the pipe body 50 is hooked by the annular inner protrusions 58, and the disconnection from the pipe joint 53 is prevented.
[0004]
As shown in FIG. 11, the pipe joint 53 is composed of two arcuate members 55 and 55 divided in half, and flanges 55a are provided at both ends of the arcuate member 55 in the circumferential direction. And is formed into a cylindrical shape by fastening the flange portions 55a with bolts 56 and nuts 57 at the time of external mounting to the connecting portion P.
[0005]
[Problems to be solved by the invention]
By the way, after the connection, a force in the tube removal direction (a direction in which both the tube bodies 50 and 50 are separated from each other in the tube axis direction) acts on the tube body 50 due to the fluid pressure in the tube body 50. Then, it acts on the annular inner protrusion 58 via the side surface 52a on the tube end side of the outer circumferential groove 52.
[0006]
However, in the above-described conventional tube body, the outer peripheral groove 52 is formed in a rectangular shape in cross section, and therefore, as shown in FIG. 12, the annular inner protrusion 58 has a force in the tube axis direction from the side surface 52 a on the tube end side of the outer peripheral groove 52 ( The arrow N1) in the figure is received. That is, the annular inner protrusion 58 receives a force from the pipe body 50 in a direction orthogonal to the projecting direction, and the annular inner protrusion 58 may be damaged due to fatigue or the like by this force.
[0007]
The present invention has been made in view of the above problems, and the problem to be solved to provide a tube connection structure can effectively prevent damage to the annular projection of the pipe joint.
[0008]
[Means for Solving the Problems]
The technical means that the present invention has taken in order to solve the above problems is that a pair of pipe bodies having an annular outer circumferential groove on the outer peripheral surface of the end portion, and open end faces of both pipe bodies to connect the pair of pipe bodies A joint formed by a pair of annular inner projections that are externally attached to both pipes so as to cover the connecting portions facing each other over the entire circumference, and that fit into the outer circumferential groove with the tip in contact with the outer circumferential groove. A joint body comprising: a main body; and an annular seal member that is mounted between an inner circumferential surface between both annular inner protrusions of the joint body and an outer circumferential surface of the end portions of both pipe bodies, and seals the connecting portion. Is provided with a plurality of arc-shaped members with connecting holes drilled in the tube axis direction at both ends in the circumferential direction, and the circumferential ends of the arc-shaped members are overlapped and overlapped A connecting pin is inserted into both connecting holes, and a plurality of arc-shaped members are connected by the connecting pin to thereby form a ring. It is configured to be externally attached to both pipes, and the annular inner projections fit into both outer circumferential grooves, so that both coupling holes overlap and the coupling pin can be fitted, and the coupling pin is fitted , A connecting structure of tubular bodies that can confirm that the annular inner protrusions are fitted in both outer circumferential grooves,
In that the inclined surface side surface of the pipe end of the peripheral groove.
[0009]
After such tube is connected by a pipe joint, the forces acting on the side surface or et annular inner projection of the tube end side of the circumferential groove when the two pipe members attempted to de-tube, with the said side inclined surface Therefore, the force is inclined outward from the tube axis direction by a predetermined angle. That is, the force acting on the annular inner protrusion from the tube has a component in the direction in which the annular inner protrusion is to be expanded, while the annular inner protrusion is annular. Strong.
The inclined surface includes an inclined concave surface and an inclined convex surface.
[0010]
In addition, it is preferable that the outer peripheral groove is formed in a substantially V shape in cross section. After the connection, the force opposite to that described above, i.e., the force that the two tube bodies try to approach each other may be considered to act on the tube as an external force. Since the force received from the side surface opposite to the tube end is also inclined outward by a predetermined angle, damage to the annular inner protrusion can be similarly prevented.
[0011]
In addition, when the tube body is relatively thin, the outer peripheral groove is generally formed by so-called grooving, but in that case, by making the cross-sectional view substantially V-shaped, Compared to the case, the pressing force at the time of grooving can be small, more accurate and easy grooving can be done, and since the pressing force can be small, especially a high hardness tube body such as a stainless steel tube. Corrosion that may occur when grooving is performed can be prevented. Further, warping on the tube end side starting from the outer peripheral groove 5 can be prevented, and the shape of the open end surface of the tube body can also be maintained.
[0012]
Further, when the outer peripheral groove is formed in a substantially V shape in cross-sectional view in this way, it is preferable to form the bottom of the outer peripheral groove in a curved shape instead of a sharp shape, thereby reducing the stress concentration at the location where the outer peripheral groove is formed. Can be relaxed. In particular, a tubular body is relatively thick, in the case of forming by cutting a circumferential groove is larger effect can be relaxed easily caused stress concentration at the bottom near near the circumferential groove.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a tubular body connecting structure according to the present invention will be described with reference to the drawings.
A tubular body 1 with an outer peripheral groove shown in FIG. 1 is a relatively thick steel pipe or resin pipe, and an outer peripheral groove 5 is formed on the outer peripheral surface 4 of the end portion over the entire periphery. The outer peripheral groove 5 is formed in a substantially V shape in cross section as shown in FIG. 2, and its bottom portion 5c is curved.
[0014]
The opening angle θ of the outer circumferential groove 5 is set to approximately 90 degrees. That is, both side surfaces 5 a and 5 b of the outer peripheral groove 5 (side surface 5 a on the tube end side and side surface 5 b on the opposite side) are both inclined surfaces of about 45 degrees with respect to the outer peripheral surface 4.
[0015]
The opening angle θ of the outer circumferential groove 5 is preferably set to approximately 60 degrees to approximately 100 degrees. That is, it is preferable that the inclination angle α of the side surfaces 5a and 5b with respect to the outer peripheral surface 4 is set to approximately 40 degrees to approximately 60 degrees.
[0016]
In addition to the bottom 5c having a curved surface, it may be flat as indicated by a two-dot chain line A in FIG. 2, or may be sharp.
However, in the case of a relatively thick steel pipe or the like, the outer peripheral groove 5 can be formed by cutting. However, when the outer peripheral groove 5 is formed by cutting, the thickness of the portion where the outer peripheral groove 5 is formed is smaller than that of other parts. Therefore, it is preferable not to make the bottom 5c sharp, but to reduce the stress concentration by making it curved or flat.
In addition, as a pipe body 1 with an outer periphery groove | channel, joint pipes, such as a T-shaped pipe and an elbow pipe, are included besides a straight pipe.
[0017]
The outer circumferential grooved tube body 1 is of a type in which a cylindrical tube joint provided with a pair of annular inner protrusions is connected by being externally attached to a connecting portion of both tube bodies. , three split, six split etc., as possible out be those of the configurations in a cylindrical shape by connecting means when divided and outer mounting multiple split.
[0018]
Hereinafter, an example of the connection structure suitable for the connection of the outer peripheral grooved tubular body 1 of the present invention will be described.
3 and 4 show a state in which both the tubular bodies 1 and 1 are coupled by the coupling structure of the tubular bodies.
The connecting structure, apertures end face 1a, the tubular body 1, 1 1a each other are arranged opposite case Migihitsuji, Ryokan to cover over the coupling portion P of the two pipe members 1 and 1 all around A pipe joint 2 provided with a pair of annular inner projections 6 that are externally attached to the bodies 1 and 1 and fit into the outer circumferential groove 5, and an inner circumferential surface between both annular inner projections 6 and 6 of the pipe joint 2 An annular seal member 3 that is mounted between the outer peripheral surfaces 4 and 4 of the end portions of the tubular bodies 1 and 1 and seals the connecting portion P is configured.
[0019]
As shown in FIG. 5, the pipe joint 2 includes a plurality of arc-shaped members 8 having connecting holes 7 drilled in the pipe axis direction at both ends in the circumferential direction. The ends are overlapped, and a connecting pin 9 is inserted into the overlapping connecting holes 7, 7, and a plurality of arc-shaped members 8 are connected by the connecting pins 9 to form a cylindrical shape when externally mounted. It is a configuration. Further, when the annular inner projections 6 are fitted in both the outer circumferential grooves 5 and 5, both the coupling holes 7 and 7 are overlapped to allow the coupling pin 9 to be fitted. When the coupling pin 9 is fitted, both the outer circumferential grooves 5 and 5 are fitted. , 5 can confirm that the annular inner protrusions 6 and 6 are fitted. This will be described in more detail below.
[0020]
First, the annular seal member 3 is made of rubber, and covers the outer periphery of the connecting portion P over the entire circumference so as to seal the connecting portion P from the outer peripheral surface side. The outer peripheral surfaces 4 and 4 are externally mounted, and the inner peripheral surface thereof abuts on the outer peripheral surface 4 of the end portion of the tube body 1. In addition, a stopper wall 10 that protrudes over the entire circumference of the opening end surface 1a of each tubular body 1 protrudes from the center of the inner peripheral surface of the annular seal member 3, and both side surfaces of the stopper wall 10 are provided. Are in contact with the open end faces 1a and 1a, respectively. By providing the stopper wall 10, there is an advantage that corrosion of the opening end face 1a is prevented.
[0021]
A tubular pipe joint 2 is externally mounted on the outer peripheral side of the annular seal member 3 so as to cover the entire circumference of the annular seal member 3. In addition, annular inner projections 6 that fit into the outer circumferential grooves 5 are provided on the inner circumferential side on both ends of the pipe joint 2 in the tube axis direction, and the distal ends of the annular inner projections 6 are formed in a curved shape. The annular inner protrusion 6 is in contact with the curved bottom 5c and both side surfaces 5a, 5b of the outer circumferential groove 5 over substantially the entire circumference. And the annular recessed part which became depressed toward the outer peripheral side is formed in the inner peripheral surface between both the annular inner projections 6, 6, and the annular recessed part and the end outer peripheral surfaces 4, 4 of both tubular bodies 1, 1 The annular seal member 3 is located therebetween, and the inner peripheral surface of the annular recess is in close contact with the outer peripheral surface of the annular seal member 3.
[0022]
Further, the pipe joint 2 is formed into a cylindrical shape when externally mounted by connecting three arcuate members 8 divided into three parts (divided into 120 degrees) by three connecting pins 9 as connecting means. The
[0023]
The three arc-shaped members 8 have substantially the same shape as a whole, and the inner peripheral surface side has the same radius, and as shown in FIG. 5, one end portion in the circumferential direction is the center in the width direction (tube axis direction). Both end portions in the width direction are male convex portions 11 projecting toward the tip end, and the other end portions on the opposite side are engageable with the male convex portions 11 of other arcuate members 8 in the center. Is a female recess 12 protruding toward the tip side. Further, the male convex portion 11 and the female concave portion 12 are provided with a connecting hole 7 into which the connecting pin 9 can be fitted in the tube axis direction, and the male convex portion 11 of one arcuate member 8 has another arc shape. Engaging with the female recess 12 of the member 8, the end portions in the circumferential direction of both arc-shaped members 8, 8 are overlapped.
[0024]
Then, the connecting pin 9 is fitted in both the overlapping connecting holes 7 and 7 in the tube axis direction, so that the three arc-shaped members 8, 8, 8 are connected to each other at a total of three locations, so that the tubular tube By forming the joint 2 and being connected in a cylindrical shape, the annular inner protrusion 6 and the like are also annular.
[0025]
Procedure for connecting I by the according pipe joint 2 and the annular seal member 3 a pipe 1,1 is described below.
By engaging the male and female ends of each other arcuate member 8 at both ends in the circumferential direction of one arcuate member 8 and inserting the connecting pins 9 respectively, three arcuate members 8, 8, 8 are connected in series. Since the connecting pin 9 is fitted in the tube axis direction, the arcuate members 8 can rotate with respect to the connecting pin 9 as a support shaft.
[0026]
Then, as shown in FIG. 6, the annular seal member 3 is attached to one tubular body 1 from the opening side, and the other tubular body 1 connected to the opposite side of the annular seal member 3 is inserted to connect both tubular bodies 1 and 1 together. Facing each other, the above-described chain-shaped pipe joint 2 is externally attached to the connecting portion P.
[0027]
For example, as shown in FIG. 7, the central arcuate member 8 is brought into contact with the lower side of the tube 1, and the other two arcuate members 8 and 8 are rotated inward from both sides of the tube 1. The male projection 11 of the arcuate member 8 is engaged with the female recess 12 of the other arcuate member 8 so that the connecting holes 7 and 7 are overlapped. When the connecting holes 7 and 7 are overlapped with each other, the last connecting pin 9 can be fitted. By fitting the connecting pin 9, the external fitting of the pipe joint 2 is completed, and the connecting work of the pipes 1 and 1 is completed. Also ends.
[0028]
When connected as described above, the annular inner protrusion 6 comes into contact with both side surfaces 5a and 5b of the outer peripheral groove 5 as shown in FIG. On the other hand, not only a straight pipe but also a joint pipe such as an elbow pipe or a T-shaped pipe as shown in FIG. 6 is connected in the piping path. By acting on the inner wall surface, a force in the tube removal direction acts on both the tubular bodies 1, 1, and this force acts on the annular inner protrusion 6 via the side surface 5 a on the tube end side of the outer circumferential groove 5.
[0029]
However, the force (arrow N2 in FIG. 8) acting on the annular inner protrusion 6 is a force inclined obliquely outward because the side surface 5a on the tube end side of the outer circumferential groove 5 is an inclined surface of approximately 45 degrees. . On the other hand, since the annular inner protrusion 6 is annular, it is structurally strong against the force in the diameter expanding direction. Therefore, the damage of the annular inner protrusion 6 is less likely to occur than when a force is applied in the tube axis direction as in the prior art, and is particularly advantageous for metal fatigue, which is an important problem for this type of piping. It is. The larger the inclination angle α of the side surface 5 a with respect to the outer peripheral surface 4 (the opening angle θ of the outer peripheral groove 5), the more advantageous in terms of strength of the annular inner protrusion 6. Since it is easy to come off, the inclination angle α of the side surface 5a with respect to the outer peripheral surface 4 is preferably about 40 degrees to about 60 degrees.
[0030]
Further, in the connecting portion P of FIG. 3, when the tube body 1 receives an external force such that both the tube bodies 1 and 1 are relatively close to each other, the annular inner protrusion 6 is forced from the side surface 5 b on the opposite side of the outer circumferential groove 5. However, even in this case, by forming the outer peripheral groove 5 in a substantially V shape in cross section as in the present embodiment, it is strong against the force as described above. The damage of the annular inner protrusion 6 can be prevented.
[0031]
In addition, by making the cross-section substantially V-shaped, the relative displacement in the tube axis direction of the pipe joint 2 with respect to the tube body 1 is easily corrected, and the annular inner protrusion 6 is positioned at the substantially center in the width direction of the outer circumferential groove 5. It can be easily positioned. still. When the tip of the annular inner projection 6 is curved, this position correction is also smooth.
[0032]
In addition, in the said embodiment, although the comparatively thick tube 1 was demonstrated, in the case of the comparatively thin tube 1 as shown in FIG. 9, there exists an effect similarly. In the tubular body 1, the outer peripheral groove 5 having a substantially V shape in cross section is formed so that the bottom 5c is flat.
[0033]
In general, when the tube is relatively thin, the outer circumferential groove is formed by a groove processing method called grooving. This is a processing method in which a tubular body is partially plastically deformed by pressing a tool from the outer peripheral surface toward the radial center. Therefore, in the case of a steel pipe having a relatively low hardness, the outer peripheral groove having a rectangular cross-sectional view can be easily grooved as in the prior art. However, in the case of a high-hardness tubular body such as a stainless steel tube or a titanium tube, when trying to process the outer peripheral groove having a rectangular cross section, a very high pressing force is required. Corrosion may occur in the vicinity of the outer circumferential groove after processing. In addition, both sides of the outer circumferential groove warp outward, and the diameter of the opening end face becomes particularly large or irregular. Therefore, conventionally, it has been impossible to substantially process the outer peripheral groove into a high hardness pipe such as a stainless pipe.
[0034]
However, if the outer peripheral groove 5 is made substantially V-shaped in cross-section as described above, the pressing force at the time of grooving can be reduced, corrosion after processing can be prevented, and easy and accurate grooving can be performed. There are advantages.
[0035]
【The invention's effect】
As described above, since the side surface on the tube end side of the outer peripheral groove is an inclined surface, the direction of the force acting on the annular inner projection when the tube body is about to come out of the pipe joint is the tube axis direction. Compared to the body, the durability of the annular inner protrusion is increased and damage due to fatigue or the like can be prevented.
[Brief description of the drawings]
FIG. 1 is a half sectional view of a tubular body with an outer peripheral groove according to an embodiment of the present invention.
FIG. 2 is an enlarged sectional view of the same part.
FIG. 3 is a view showing a connected state of the tubular body and showing a cross section taken along the line AA in FIG. 4;
FIG. 4 is an explanatory view of the connected state of FIG. 3 as viewed from the tube axis direction.
FIGS. 5A and 5B show a main part of a pipe joint used for connecting the pipe bodies, where FIG. 5A is a front view and FIG. 5B is a side view.
FIG. 6 is an explanatory view showing a connecting process of the tubular bodies.
FIG. 7 is an explanatory view showing a connecting process of the tubular bodies.
FIG. 8 is a partially enlarged cross-sectional view showing a connected state of the tubular body.
FIG. 9 is an enlarged cross-sectional view showing a connected state of a tubular body with an outer peripheral groove according to another embodiment.
FIG. 10 is a cross-sectional view showing a connection state of a conventional tubular body.
FIG. 11 is a front view showing a pipe joint used for connecting conventional pipe bodies.
FIG. 12 is an enlarged cross-sectional view showing a connection state of a conventional tubular body.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Tube body with outer peripheral groove (tube body), 1a ... Open end surface, 2 ... Pipe joint, 3 ... Ring seal member, 4 ... End outer peripheral surface (outer peripheral surface), 5 ... Outer peripheral groove, 5a, 5b ... Outer peripheral groove 5c ... bottom of outer peripheral groove, 6 ... annular inner protrusion, 7 ... connecting hole, 8 ... arc-shaped member, 9 ... connecting pin, 10 ... stopper wall

Claims (3)

A pair of tubes having an annular outer circumferential groove on the outer peripheral surface of the ends, and both tubes so as to cover the entire circumference of the connecting portion where the open end faces of both tubes face each other in order to connect the pair of tubes. A joint main body provided with a pair of annular inner projections fitted to the outer circumferential groove in a state in which the tip is in contact with the outer circumferential groove, and an inner circumferential surface between both annular inner projections of the joint main body. An annular sealing member that is mounted between the outer peripheral surfaces of the ends of both pipes and seals the connecting portion, and the joint body has connecting holes at both ends in the circumferential direction in the tube axis direction. A plurality of circular-arc-shaped members that are drilled, the circumferential ends of the circular-arc-shaped members are overlapped with each other, and a connection pin is fitted into the overlapped connection holes, and the connection pins are used to connect a plurality of circles; It is a structure that is formed in an annular shape by connecting arc-shaped members and is externally attached to both pipes, Each of the annular inner projections fits into each other so that both coupling holes overlap and the coupling pin can be fitted, and when the coupling pins are fitted, it is possible to confirm that the annular inner projections are fitted in both outer peripheral grooves. A connected structure,
Outer peripheral groove of the tube body, the connection structure of the tubular body, characterized in that the side surface of the tube end is formed on the inclined surface. The tube connecting structure according to claim 1 , wherein the outer circumferential groove is formed in a substantially V shape in a cross-sectional view. The peripheral groove, connecting structure according to claim 2, wherein the tubular body, characterized in that its bottom is formed in a curved shape.

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