JP7168930B2 - Connection structure for fittings and pipes - Google Patents

Description

TECHNICAL FIELD The present invention relates to a connection structure between a pipe joint and a pipe, and more particularly to a connection structure suitable for fire-extinguishing sprinkler piping.

Conventionally, a thin metal pipe is plastically processed with a manual work tool to form uneven corrugated, triangular and trapezoidal mountain-shaped ridges, and to have a cut at one place on the circumference and an uneven corrugated, triangular and trapezoidal shape on the inner peripheral surface. A retaining ring having a locking recessed groove is fitted on the uneven corrugations and ridges of the pipe, and a cap nut is screwed onto the male screw portion of the joint body, so that the tapered surface inside the cap nut. An invention has been proposed in which the retaining ring is diameter-reduced and deformed to connect the pipe to the joint body (see Patent Document 1).

Japanese Patent No. 5953410

By the way, the conventional connection structure (connection method) described in Patent Document 1 is applied to a thin metal pipe having a thickness of 0.7 mm to 1.5 mm.

On the other hand, emergency fire-fighting pipes (fire-fighting sprinkler pipes) use carbon steel pipes with a pipe outer diameter of 34 mm or more and a large wall thickness of several mm, as described in Patent Document 1. The pipe connection structure (method) described in Patent Document 1 cannot form uneven corrugations or locking grooves in the pipe with a roller while holding a manual work tool with one hand and rotating it around the pipe. In the technical field of (equipment), it has not been used and technical improvements have been delayed until today.

11 and 12 show a housing type pipe joint 76 conventionally practiced in emergency fire-fighting piping (fire-fighting sprinkler piping). This housing-type pipe joint 76 has a pair of housing halves 77, 77 which are fitted 180° symmetrically, each housing half 77 having a semi-arc portion 78 and a pair of projecting pieces extending from both ends thereof. It has parts 79,79. Further, the projecting pieces 79, 79 are tightened by the bolt _- nut connections 80, 80 to make the pair of housing halves 77, 77 annular, and to _{concentrically} connect the pipes P1, P1 to be connected. It is a structure that (connects).
A gasket 81 is accommodated inside, and the lip of the gasket 81 is arranged so that the water in the pipes P ₁ , P ₁ connected to each other through a minute gap 82 (or in contact with each other) does not leak to the outside. 83 is _elastically pressed against the outer peripheral surface of the tip of the pipe P1.

_The pipe P1 is made of steel (carbon steel) and is a thick-walled pipe. An inner flange portion 87 on the inner peripheral edge side of the semicircular arc portion 78 is fitted (engaged) in the recessed peripheral groove 86 from the radially outer side.

The conventional housing type pipe joint 76 shown in FIGS. 11 and 12 has the following problems.
(i) Since the bolt and nut connections 80, 80 are provided, the worker must use a working tool such as a wrench to perform the screwing work. There is also a risk of dropping the
(ii) _Each pipe P1 and the housing type pipe joint 76 should be connected to each other because the contact between the groove bottom surface of the recessed peripheral groove 86 and the inner flange portion 87 (in the axial direction) is extremely small. There is _{a risk} that the axis 88 of the pipe P1 and the axis 88 of the pipe P1 will be connected while being inclined (not coinciding).
(iii) Since a large bending moment acts on the semicircular arc portion 78 when it is connected with bolts and nuts, the thickness must be sufficiently large, which increases the weight and makes it compact in the radial direction. It is difficult to plan
(iv) The gasket 81 has a large cross section. Therefore, the possibility of damage also increases, and durability is also a problem.
(v) _The work of threading the bolt _- nut connection 80 and the work of aligning the mutual axes 88 of the pipes P1 and P1 to be connected must be performed at the same time. There is a need.
Therefore, the present invention solves these problems (i) to (v), allows workers to easily and efficiently connect pipes, and facilitates the alignment of the axial centers of the pipes to be connected. To reduce the weight and size in the radial direction, to reduce the size of a sealing material, to improve sealing performance, and to enable even a small number of workers to easily perform connection work.

A connection structure according to the present invention comprises a joint body and a pressing and retaining ring attached to the joint body, and a thick steel pipe to be connected is provided with a locking ridge. locking means for locking each other by fitting the pressing and retaining ring in the axial direction and rotating the pressing and retaining ring at a small angle in the circumferential direction; and a pipe joint configured such that the pressing retaining ring and the joint main body are sandwiched from the outer and inner sides in the axial direction with respect to the locking ridge portion of the pipe by the locking means. In the pipe connection structure, the locking ridge is formed of a metal spring ring having a rectangular cross section fitted into a recessed circumferential groove formed at a position a predetermined small distance from the tip end face of the pipe, Moreover, the groove width dimension of the concave circumferential groove is set larger than the width dimension of the spring ring, and the spring ring elastically presses against the bottom surface of the concave circumferential groove and slides in the axial direction by a small distance. The locking ridge portion is formed by the radially outward projecting portion of the spring ring that is held as possible and projects radially outward from the outer peripheral surface of the pipe . A clamping state in which the axial side end face of the spring ring having a rectangular cross section is clamped by the front end face orthogonal to the center and the pressing surface orthogonal to the axial center of the pressing and holding ring, wherein the spring ring is clamped. A mutual contact surface between the radially outwardly protruding portion and the joint body and a mutual abutting surface between the radially outwardly projecting portion and the pressing and retaining ring are configured as orthogonal surfaces perpendicular to the pipe axis, and When a pull-out force acts on the pipe, the spring ring abuts on one side surface of the recessed circumferential groove on the tip side, and a stepped portion is formed inside the hole of the joint body to provide a pipe. When a pushing force acts on the stepped portion, the pipe end surface is configured to abut on the stepped portion.

Further, when the thickness dimension in the cross section of the spring ring S is Ts, the relationship between the width dimension Ws and the width dimension Ws is 0.8·Ts≦Ws≦2.0·Ts.
Further, the width dimension Ws of the spring ring S is set such that 0.40·W ₂ ≤Ws≤0.70·W ₂ with respect to the groove width dimension W ₂ of the recessed circumferential groove .
Further, the recessed circumferential groove is formed by rolling .

According to the connection structure of the present invention, connection work can be easily and quickly performed without using a work tool such as a spanner. In addition, it is possible to easily and reliably form the engaging ridges on a thick pipe made of steel, which is difficult to be plastically worked. Furthermore, the pull-out resistance is large and stable.

Further, according to the connection method of the connection structure of the present invention, the operator can easily and quickly perform the connection work without using a working tool such as a wrench. In addition, by using the metal spring ring, which is a separate part from the pipe, the worker can easily (manually) form the locking ridges. The connected connection structure stably exhibits high pull-out resistance. In addition, the pressing and retaining ring can be manually and smoothly attached, making the work easy, and even when working at a high place, there is little risk of the parts falling from the high place, and the work is easy.

Furthermore, while utilizing only the concave circumferential groove in the housing type joint (see Figs. 11 to 14), which has been used for a long time, as it is for the concave circumferential groove of the present invention, we reconstructed a completely new connection method, In the technical field of sprinkler piping, it is possible to transfer to the connection method of the present invention very smoothly.
Furthermore, since the spring ring is movable in the axial direction within the concave circumferential groove, even if there is a dimensional error in the component parts, it is possible to smoothly assemble and connect the whole.

It is explanatory drawing which shows one Embodiment of this invention and shows the process of forming a recessed circumferential groove in the outer peripheral surface of a thick pipe. It is sectional drawing which shows the process which fits a metal spring ring in a concave circumferential groove, (A) is principal part sectional drawing, (B) is principal part expanded sectional drawing. It is a figure which shows an example of a metal spring ring, (A) is a front view, (B) is a cross-sectional side view, (C) is principal part enlarged explanatory drawing. It is explanatory drawing of the connection method. It is explanatory drawing of the connection method. It is explanatory drawing of the connection method. It is explanatory drawing of the connection method. FIG. 4 is a cross-sectional view showing a connection completed state; FIG. 10 is a drawing showing a pressing and holding ring, (A) is a front view, (B) is a cross-sectional view taken along line BB of (A), and (C) is a rear view. It is a front view of a joint main body. It is a front view showing a conventional example. FIG. 10 is a cross-sectional view showing a conventional example; FIG. 10 is an explanatory view of a state of use of a conventionally used rolling apparatus; FIG. 10 is a partial cross-sectional explanatory view showing a rolling device and a rolling method for a concave peripheral groove which have been conventionally used and which are also utilized in the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below based on the illustrated embodiments.
1 to 10, a concave peripheral groove 2 is formed on the outer peripheral surface ₁ of a thick steel pipe P1 by rolling at _a position a predetermined small dimension L1 from the pipe tip end surface 7. As shown in FIG.

The present invention is a connection structure between a pipe joint and a pipe that is particularly suitable for fire _- extinguishing sprinkler piping (emergency fire-extinguishing piping). It has a large diameter and a thickness dimension T of 3.0 mm or more and 6.0 mm or less, which is called "thickness" in the present invention. Moreover, the predetermined small dimension L1 shown in FIG. ₁ is preferably 15 mm or more and 20 mm or less. If the predetermined small dimension L1 is set to ₁₅ mm or more and 20 mm or less, the rolling device 85 shown in FIGS. 13 and 14, which has been used for many years, can be used as it is. If it is less than the lower limit, the pipe axis Lp and the joint body axis become inclined (not aligned) in the pipe connection complete state (see FIG. 8), making it difficult to connect reliably. Sometimes. Conversely, when the upper limit is exceeded, the compactness of the connection structure is hindered.

As shown in FIG. 3, a metal spring ring S of spring steel or the like having a cut 3 along the circumference and a rectangular cross section is fitted into the concave circumferential groove ₂ of the pipe P1 as shown in FIG. As shown by arrows K ₁ and K ₂ in FIG. 2 , if the pipe end of the pipe P ₁ is pushed in, the spring ring S expands and elastically deforms, slides in the axial direction, and is fitted into the concave circumferential groove 2 .
That is, the inner diameter dimension of the spring ring S in the free state is set slightly smaller than the outer diameter dimension of the pipe and further the outer diameter dimension of the groove bottom surface 2A of the concave peripheral groove 2 .

By hand or using _a simple work tool, the operator slightly expands the diameter of the spring ring S and pushes it in as indicated by the arrows K1 and K2 in _FIG . It falls into the recessed peripheral groove 2 by force and lightly presses against the groove bottom surface 2A.
Furthermore, as shown in FIG. 2, the width dimension Ws of the spring ring S is set sufficiently smaller than the groove width dimension W2 of the concave circumferential groove ₂ . As a result, the spring ring S is elastically pressed against the groove bottom surface 2A of the concave circumferential groove 2 (as indicated by the arrow f in FIG. 2(B)), and the spring ring fitted into the concave circumferential groove 2 is pressed. As shown in FIG. 2(B), S is held in the recessed peripheral groove 2 so as to be slidable in the axial direction As by a small distance in a press-contact state.

In this manner, the inner peripheral surface of the spring ring S is elastically pressed against the groove bottom surface 2A of the concave peripheral groove 2, and is held so as to be slidable in the axial direction As. A radially outward projecting portion 10 projecting radially outward Rs from the outer peripheral surface 1 forms a locking projection Z (the operation and function of this locking projection Z will be described later). do).

4 to 8 are diagrams sequentially showing the steps of subsequent work.
The pipe joint 8 comprises a joint body 11 and a pressure retaining ring 5 in the illustrated example. As will be described later, the pipe joint 8 has a structure in which the pressure holding ring 5 can be freely connected and separated from the joint main body 11 by manual rotation at a small angle.

FIGS. 4 and 5 show the tip of the pipe P1 having _a locking projection Z formed by fitting a spring ring S, which was _a separate part from the pipe P1, into the concave circumferential groove ₂ of the pipe P1. It is approached as indicated by the arrow Kp and inserted into the hole 11A of the joint body 11 as shown in FIG.
_If the pipe P1 is pushed in as shown in FIG. Manually rotate in the N direction by a small angle---for example, 30.degree. to 60.degree.--.

By this light manual rotation of a small angle, the distal end portion of the joint body 11 and the proximal end portion of the pressure retaining ring 5 are coupled (locked) to each other by the locking means 50, as shown in FIG.
In the locked (coupled) state shown in FIG. 7, the spring ring S (locking ridge Z) is held between the pressure holding ring 5 and the joint body ₁₁ , and the pipe P1 extends in the axial direction E. is connected so that it cannot be pulled out. That is, FIG. 7 shows a state in which the pipe is prevented from being pulled out.

FIG. 8 shows a state in which the connection is completed, and a state in which the anti-rotation pin 12 is inserted in order to prevent the locking means 50 from coming off due to the pressing and holding ring 5 rotating in the direction opposite to the arrow N in FIG. showing.
Specifically, as shown in FIGS. 8 and 9, a through hole 36 for pin insertion is provided in the pressure retaining ring 5, and if the pin 12 is inserted into this through hole 36 in the direction of the arrow Q, the joint body 11 can be removed. A pin 12 is engaged with one side of the four protrusions 37 to prevent reverse rotation.

Here, the method of connecting the pipe joint and the pipe described above will be described from another point of view. As shown in FIGS. 1 to 8, a joint main body 11 and a pressure holding ring 5 that can be attached to the joint main body 11 are provided. ) approach the tip of the joint body 11 from the axial direction as indicated by the arrow Kp, and then manually rotate it by a small angle in the circumferential direction (in the direction of the arrow N) (as shown in FIG. 7). , the fitting 8 is provided with locking means 50 for interlocking.

In the connection method for connecting such a pipe joint 8 and the pipe P1 so as not to be pulled out in the axial direction, _first , as shown in FIGS. ₁ and 14 (FIG. 13), the pipe P1 is A rolling device 85 is used to form a recessed circumferential groove 2 in the outer peripheral surface ₁ of the thick pipe P1, and a C-shaped metal spring ring S is fitted into the recessed circumferential groove 2 and locked. A ridge Z is formed on the outer peripheral surface ₁ of the pipe P1.

Next, as shown in FIGS. 4 and ₅ to 6, the pipe P1 is inserted into the joint main body 11, the pressure retaining ring 5 is brought closer to the joint main body 11, and the state shown in FIG. 6 is changed to that shown in FIG. As shown, manual rotation is applied by a small angle in the range of 30° to 60°, preferably 45° to 60° in the direction of arrow N, and the locking means 50 engages the pressure retaining ring 5 and the joint body 11. combine.
As a result, the tip surface 11C of the joint body 11 perpendicular to the axis and the pressing surface 5C of the pressure retaining ring 5 (see FIG. 9) perpendicular to the axis of the spring ring S with a rectangular cross-section are pressed axially. The end surfaces 40 and 41 (see FIG. 3) are put in a sandwiched state . Since the side end surfaces 40 and 41 of the spring ring S form planes perpendicular to the axis, the planes perpendicular to the axis are in pressure contact with each other, and unnecessary external force in the radial direction does not act on the spring ring S. As a result, there is an advantage that the rotation torque required when manually rotating in the direction of the arrow N in FIG. 7 is small and the work is easy.

Next, a connection structure for a pipe joint and a pipe according to the present invention will be described. As shown in FIGS. 1 to 8, this connecting structure comprises a joint body 11 and a pressure retaining ring 5 attached to the joint body 11, and _a thick steel pipe P1 to be connected. An engaging projection Z is protrudingly provided on the joint main body 11, and the pressing and holding ring 5 is fitted and circumferentially fitted to the distal end outer peripheral portion 11D of the joint body 11 and the inner peripheral portion 5D of the pressing and holding ring 5 by approaching in the axial direction. Locking means 50 are provided for locking _each other at a small angle of rotation N in the direction of rotation. It is configured such that it is sandwiched from the outside and inside of the portion Z in the axial direction.

In addition, the locking projection Z is formed by a metal spring ring S having a rectangular cross section, which is fitted in the rolling concave peripheral groove 2 formed at _a position of a predetermined small dimension L1 from the pipe end surface 7. It is
Further, the groove width dimension W2 of the recessed circumferential groove ₂ is set larger than the width dimension Ws of the spring ring S, so that the spring ring S elastically presses against the groove bottom surface 2A of the recessed circumferential groove 2 and axially moves. The locking projection Z is formed by the radially outwardly projecting portion 10 of the spring ring S which is held so as to be slidable in the direction As by a small distance and projects radially outwardly Rs from the outer peripheral surface 1 of the pipe. be.

Next, in the cross section shown in FIG. 3(C), the following formula holds between the width dimension Ws and the thickness dimension (radial direction dimension) Ts of the spring ring S.
That is, 0.8·Ts≦Ws≦2.0·Ts
If it is less than the lower limit, the spring ring S tends to fall (in the cross section), or it becomes difficult to move smoothly in the axial direction As. Conversely, when the upper limit is exceeded, the width dimension Ws approaches the groove width dimension W2 of the concave circumferential groove ₂ , and movement in the axial direction As within the concave circumferential groove 2 is restricted. This may make it difficult to assemble the pressure retaining ring 5 to the joint body 11 . Moreover, if the dimensional tolerance of each part to be assembled is large, the assembly may become difficult.

Next, in FIG. 2(B), the width dimension Ws of the spring ring S is set with respect to the groove width dimension W2 of the recessed circumferential groove ₂ as shown in the following formula.
0.40·W ₂ ≦Ws≦0.70·W ₂
If it is less than the lower limit, the shear strength of the spring ring S is insufficient, and the spring ring S tends to fall over. Conversely, when the upper limit is exceeded, the movement allowance (slidable dimension) in the axial direction As becomes too small.

8 (FIG. 7), when the pipe pullout force acts, the spring ring S comes into contact with one side surface 2C on the tip side of the recessed circumferential groove 2, and exerts pullout resistance. do.
Conversely, a stepped portion 20 is formed inside the hole portion 11A of the joint body 11 with which the pipe tip end surface 7 abuts when _a pushing force acts on the pipe P1.
In FIG. 7, there is a small gap G between the stepped portion 20 and the pipe tip surface 7, but when _a pushing force acts on the pipe P1, the pipe tip surface 7 moves toward the stepped portion 20. further insertion is blocked.

Next, the fitting and holding portion between the pressing and holding ring 5 and the spring ring S will be described. As shown in FIGS. As shown in FIGS. 2 to 5, when the pressing and holding ring 5 is moved toward the tip of the pipe, the spring ring S having a rectangular cross section previously fitted in the groove 2 is removed from the notch. Mates to 31. The pressing surface 5C constitutes a part of the fitting notch 31. As shown in FIG.

The pressing surface 5C of the notch 31 is an orthogonal surface perpendicular to the axial center (of the pressing and retaining ring 5). Therefore, the mutual abutment surfaces where the radially outwardly protruding portion 10 of the spring ring S having a rectangular cross section and the pressing surface 5C of the pressing and retaining ring 5 abut are orthogonal surfaces perpendicular to the pipe axis Lp.
Also, the joint body 11 has a tip end face 11C formed of an orthogonal plane perpendicular to the axis (see FIG. 10), and the radial outward protrusion 10 of the spring ring S and the tip end face 11C of the joint body 11 are in mutual contact. The tangent plane is an orthogonal plane perpendicular to the pipe axis Lp.

In this way, the two mutually abutting surfaces form a plane perpendicular to the axis, so that the pressing and holding ring 5 does not receive an extra force vector in the axial direction, and a smooth manual operation can be performed with a smaller rotational torque. (see arrow N in FIG. 7).
In addition, the spring ring S itself also slides (moves) in the axial direction lightly, and reliably exerts the anti-pull-out function.

In addition, when fluid such as water passes through the connection structure according to the present invention, it is preferable to add a seal ring in order to ensure the sealing performance. 5 to 8 exemplify an O-ring as the seal ring 15. Specifically, a groove 16 is formed in the hole 11A of the joint body 11, and the seal ring 15 is fitted in the groove 16. _With the pipe P1 inserted into the hole 11A, the seal ring (O _- ring) 15 presses against the outer peripheral surface of the pipe P1 to exhibit sealing performance.
Further, the position where the seal ring ₁₅ is arranged is not limited to the examples shown in FIGS. It is free to make a configuration to do.

As already mentioned, the outer peripheral portion 11D of the distal end of the joint body 11 and the inner peripheral portion 5D of the pressing and holding ring 5 are provided with the locking means 50 which can be locked to each other. 50 and related shapes, structures, etc. will be additionally described below.
The joint main body 11 has a plurality of arcuate outer projections 19 and smooth arcuate bottom surfaces 45 alternately arranged on the distal end outer peripheral portion 11D (see FIGS. 4 and 10). Each outer rib portion 19 is composed of a pair of first and second outer ribs 19A and 19B. A locking groove 23 is formed between the pair of first and second outer ridges 19A and 19B.

On the other hand, as shown in FIGS. 9 and 7, a plurality of arcuate inner ridges 24 are provided on the inner peripheral portion 5D of the pressure retaining ring 5. As shown in FIG. The inner projection 24 can be engaged with the locking groove 23 of the joint main body 11 by rotating it in the circumferential direction N by a small angle. FIG. 9 shows a case in which four (four pairs) of inner ridges 24 and locking grooves 23 are provided at a pitch of 90°, and the "small angle" is about 45°.

Although not shown, if the number of pairs of the inner ridges 24 and the locking grooves 23 is 6, 5, 3, 2, etc., the "small angle" is about 30° and about 36°, respectively. , about 60° and about 90°. In short, as described above, it is possible to simply and easily engage by simply rotating manually by a small angle of 30° to 90° in the direction of arrow N.
4, 9, and 10, the locking means 50 has at least the locking groove portion 23 and the inner ridge portion 24. As shown in FIG. More specifically, the locking means 50 is composed of an outer ridge portion 19, a smooth arcuate bottom portion 45, a locking groove portion 23, and an arcuate inner ridge portion 24. As shown in FIG.

Next, referring to FIGS. 13 and 14, a method for forming (working) the recessed circumferential groove 2 (86) will be described.
The rolling device 85 has a base 51 with legs, and a drive roller 53 having a recessed circumferential groove 52, which is rotated by an electric motor, is arranged in a forward protruding manner from a casing 54, and the roller 53 is rotated by an electric motor. _The end of the pipe P1 is supported from inside the hole. The pipe to be processed P1 is rotatably held by _a support stand 55 or the like that is held horizontally, but the pipe axis 88 and the axis L52 of the driving roller ₅₃ are downwardly aligned with a predetermined eccentricity ε. and above are mutually eccentric.

The axis L ₅₆ of the driven roller 56 approaching the outer surface of the pipe P ₁ is parallel to the axes L ₅₂ and 88 of the drive roller 53 and the pipe P ₁ and contacts the outer surface of the pipe and rotates (driven). ), the driven roller 56 is fed (hydraulically or electrically) slowly in the direction of the arrow P56, and the driven roller ₅₆ moves along the wall surface of the pipe _P1 toward the concave circumferential groove 52 of the drive roller 53 which is driven to rotate. A recessed peripheral groove 2 (86) having a predetermined size and shape is formed (by rolling) while pressing.
Such rolling apparatus and rolling method have been known since around 1993.
However, the rolling apparatus 85 shown in FIGS. 13 and 14 described above has only been used for the housing type pipe joint 76 shown in FIGS.

Thus, the present inventor focused on the recessed circumferential groove 86 for fitting (locking) the inner flange portion 87 in the housing type pipe joint 76 shown in FIGS. 11 and 12 solves the problems (i), (ii), (iii), (iv), and (v) of the housing type pipe joint 76 shown in FIGS. Here, we propose an excellent connection structure (connection method) between a pipe joint and a pipe that exhibits a remarkable effect.

For many years, housing type pipe joints 76 as shown in FIGS. In fact, many 85 are arranged at the site, and the workers are also skilled in machining the concave circumferential groove 2 (86) as shown in Figs. 14 and 12, and the machining quality is stable. The present invention focuses on the point that it is good to

By utilizing the concave peripheral groove 2 (86) shown in Figs. 12 and 14, which has been used for many years, and adding the unique shape and structure shown in Figs. The present inventor believes that the present invention can greatly contribute to the relevant technical field (industry) by making use of the skillful skills of workers at the work site for connecting emergency fire extinguishing pipes (fire sprinkler pipes) and stabilizing the quality. is convinced.
As described above, it is most preferable to form the circumferential concave groove 2 by rolling. You are free to do so.

The connecting structure according to the present invention comprises a joint main body 11 and a pressure retaining ring 5 attached to the joint main body 11, and the steel thick pipe P1 for connection is provided with _a locking ridge. A portion Z is protrudingly provided, and the tip outer peripheral portion 11D of the joint main body 11 and the inner peripheral portion 5D of the pressure retaining ring 5 are fitted together by approaching the pressure retaining ring 5 in the axial direction and rotated at a small angle N in the circumferential direction. A locking means 50 for locking each other is provided, and by the locking means 50, the pressure retaining ring ₅ and the joint body 11 are axially aligned with respect to the locking projection Z of the pipe P1. A connection structure for a pipe joint and a pipe configured to be sandwiched from the outside and inside of the pipe, wherein the locking projection Z is positioned at _a predetermined small dimension L1 from the pipe tip surface 7 The groove width dimension W2 of the recessed circumferential groove ₂ is larger than the width dimension Ws of the spring ring S. The spring ring S is elastically pressed against the groove bottom surface 2A of the circumferential groove 2 and held so as to be slidable by a small distance in the axial direction As. Since the locking ridge Z is formed by the radially outwardly projecting portion 10 of the spring ring S, the spring ring S is always in pressure contact with the groove bottom surface 2A of the concave circumferential groove 2 and crosses the groove. Since it has a rectangular shape, it can be stably fitted in the recessed circumferential groove 2 and will not be unexpectedly separated from the recessed circumferential groove 2 at all. Furthermore, since the spring ring S can slide in the axial direction As within the concave circumferential groove ₂ by a small distance, the dimensional tolerance at the joint body 11, the pressure retaining ring 5 and the pipe P1 is somewhat large. Even in the (bad) case, it is possible to easily fit and couple them. Therefore, processing (manufacturing) of each component becomes easy. Alternatively, even if the dimensional tolerance at the interfitting/joining portion is slightly large (bad), excessive internal stress and distortion in the completed state of connection are reduced or eliminated by sliding of the spring ring S in the axial direction As. Fatigue fracture can be prevented after a long period of use. In addition, when the pipe connection is completed, the pipe P1 and the joint body ₁₁ are configured to be mutually rotatable _about the axis Lp. , and the other end of the joint body 11 is not adversely affected. Furthermore, during the connecting operation, the rotation of the joint body 11 or the pressing and retaining ring 5 about the axis does not have to be transmitted to the pipe P1, thereby avoiding adverse effects _on the _other end of the pipe P1.
Furthermore, the present invention has solved the problems (i), (ii), (iii), (iv), and (v) of the housing type pipe joint 76 shown in FIGS.

In addition, in the connection structure according to the present invention, when a pull-out force acts on the pipe P1, the spring ring S abuts on the _one side surface 2C of the concave circumferential groove 2 on the tip end side, and furthermore, the joint body A stepped portion 20 is formed inside the hole portion 11A of 11, and when a push-in force is applied to the pipe, the tip surface 7 of the pipe abuts on the stepped portion 20. In addition, the contact between the spring ring S having a rectangular cross section and the side surface 2C exerts _a strong pull-out resistance. The contact with the surface 7 prevents the pipe P1 from entering the hole 11A of the joint body ₁₁ excessively. In addition, when the pipe connection is completed, the pipe P1 and the joint body ₁₁ are configured to be mutually rotatable _about the axis Lp. , and the other end of the joint body 11 is not adversely affected. Furthermore, during the connection work, the rotation of the joint body 11 or the pressing and holding ring 5 about the axis is not transmitted to the pipe P1, and adverse effects _on the _other end of the pipe P1 (such as loosening of the screw connection) are prevented. avoidable.

Further, the mutual contact surface between the radially outwardly projecting portion 10 of the spring ring S and the joint body 11 and the mutual contacting surface between the radially outwardly projecting portion 10 and the pressure holding ring 5 are the pipe shaft. Since it is configured on the orthogonal plane perpendicular to the center Lp, only the pressing force (contact stress) in the axial direction is transmitted, and no extra pressing force acts in the radial direction. As a result, the rotational torque required to manually rotate the pressing and holding ring 5 (see arrow N in FIG. 7) can be reduced, and the connecting work is further facilitated.

Further, when the thickness dimension in the cross section of the spring ring S is Ts, a relational expression such as 0.8·Ts≤Ws≤2.0·Ts is established between the width dimension Ws and the width dimension Ws. As a result, the spring ring S tends to move smoothly in the axial direction As without falling (in the cross section). Moreover, the movement of the spring ring S in the axial direction As within the concave circumferential groove 2 becomes sufficiently large, and the work of assembling the pressure retaining ring 5 to the joint main body 11 is facilitated.

Further, since the width dimension Ws of the spring ring S is set to satisfy 0.40·W ₂ ≤ Ws ≤ 0.70·W ₂ with respect to the groove width dimension W ₂ of the concave circumferential groove 2 , the spring ring The shearing strength of S is maintained sufficiently high, it is possible to prevent it from collapsing in the concave circumferential groove 2, and a sufficient allowance for movement (in the axial direction) of the spring ring S in the concave circumferential groove 2 is obtained. 5 to the joint main body 11 becomes easy.

In addition, since the concave circumferential groove 2 is formed by rolling, the processing device 85 (as shown in FIG. 13) that has been used for a long time at the work site for connecting emergency fire extinguishing pipes can be used as it is. , the operator is also skilled in using the processing device 85, and can quickly and easily process the concave circumferential groove ₂ in the thick pipe P1 with high accuracy. In other words, it is possible to make use of the skillful skill of the operator, and to perform excellent pipe connection with stable quality.

As described in detail above, the connection method of the pipe joint and pipe connection structure of the present invention is such that, on the outer peripheral surface ₁ of the steel thick pipe P1, _a predetermined small dimension L1 from the pipe tip surface 7 is provided. A metal spring ring S having a rectangular cross section formed with a groove 2 and having a cut 3 at one place on the circumference is fitted into the groove 2 so that the width dimension Ws is larger than the groove width dimension W2 of the groove ₂ . The spring ring S, which is sufficiently small, is elastically pressed against the groove bottom surface 2A of the circumferential concave groove 2 and is held in the circumferential concave groove 2 so as to be slidable by a small distance in the axial direction As. A radially outward projecting portion 10 of the spring ring S projecting radially outward Rs from the spring ring S forms a locking projection Z, and is provided with a joint body 11 and a pressure holding ring 5 that can be freely connected and separated by manual rotation at a small angle. _A method in which the tip of the pipe P1 is inserted into the pipe joint 8, and the locking projection Z is held between the joint main body 11 and the pressure holding ring 5 to prevent the pipe from being pulled out. Therefore, the operator can easily and quickly make a connection exhibiting a strong pull-out resistance with a small angle manual rotation (without using a work tool). The locking ridge Z exerts a strong and reliable pull-out resistance. Since the spring ring S can move in a small amount in the axial direction As, when the pressing and holding ring 5 is manually rotated at a small angle to the joint body 11, smooth rotational coupling can be achieved (without catching). Moreover, since the spring ring S has a rectangular cross section, it is possible to achieve smoother rotational coupling. That is, it is sufficient to apply a force only in the axial direction to the spring ring S, and it is not necessary to apply a force in the direction of radial contraction. Also, there is no risk of bolts, nuts, etc. falling when working at heights. In particular, even one worker can easily and quickly perform the connection work. Thus, according to the connection method of the connection structure of the present invention, the problems (i), (ii), (iii), and (iv) of the conventional housing type pipe joint 76 shown in FIGS. 11 and 12 are solved. (v) can be resolved.

In addition, by forming the concave circumferential groove 2 by rolling, the processing device 85 (as shown in FIG. 13) that has been used for a long time at the connection work site of the emergency fire extinguishing pipe can be used as it is. It can be diverted, and the operator is also skilled in using the processing device 85, and can quickly and easily process the concave circumferential groove 2 in the thick _- walled pipe P1 with high accuracy. In other words, it is possible to make use of the skillful skill of the operator, and to perform excellent pipe connection with stable quality.

1 (pipe) outer peripheral surface 2 concave peripheral groove 2A groove bottom surface 2C one side surface 3 cut 5 pressing and retaining ring
5C pressing surface
5D inner peripheral portion 7 pipe tip surface 8 pipe joint
10 Radial outward protrusion
11 Joint body
11A hole
11C Tip surface
11D tip periphery
20 Stepped part
40 Axial end face
41 Axial end face
50 Locking means P ₁ Pipe Lp Pipe axis L ₁ Predetermined small dimension N Small angle rotation S Spring ring Ws Width dimension W ₂ Groove width dimension As Axial direction Rs Radial outward
Z Locking projection Ts Thickness

Claims (4)

A joint body (11) and a pressure retaining ring ( ₅ ) attached to the joint body (11) are provided. (Z) is protrudingly provided, and the outer peripheral portion (11D) of the front end of the joint body (11) and the inner peripheral portion (5D) of the pressing and retaining ring (5) are provided with the axial direction approach of the pressing and retaining ring (5). Locking means (50) for locking each other at fitting and small angle rotation (N) in the circumferential direction is provided. ) is a connection structure between a pipe joint and a pipe, which is configured to be held by the locking projection (Z) of the pipe (P ₁ ) from the outside and inside in the axial direction. There is
The locking projection (Z) is _a metal spring ring ( S) is formed with
Moreover, the groove width dimension (W ₂ ) of the recessed circumferential groove (2) is set larger than the width dimension (Ws) of the spring ring (S), so that the spring ring (S) is positioned in the recessed circumferential groove (2). The spring ring is held so as to be slidable by a small dimension in the axial direction (As) while being elastically pressed against the bottom surface (2A) of the groove, and protrudes radially outward (Rs) from the outer peripheral surface (1) of the pipe. The locking ridge (Z) is formed by the radially outward protrusion (10) of (S) ,
The pinched state is formed by a rectangular cross-sectional shape formed by the front end surface (11C) of the joint body (11) orthogonal to the axial center and the pressing surface (5C) of the pressing retaining ring (5) orthogonal to the axial center. A clamping state in which the axial side end faces (40) and (41) of the spring ring (S) of the surface are clamped,
Mutual abutment surfaces between the radially outwardly projecting portion (10) of the spring ring (S) and the joint body (11), and contact surfaces between the radially outwardly projecting portion (10) and the pressing and holding ring (5). The mutual abutting surfaces are configured in orthogonal planes perpendicular to the pipe axis (Lp),
Furthermore, when a pull-out force acts on the pipe (P ₁ ), the spring ring (S) abuts on one side surface (2C) of the recessed circumferential groove (2) on the tip side, and the joint body ( A stepped portion (20) is formed inside the hole (11A) of 11) so that the tip end surface (7) of the pipe comes into contact with the stepped portion (20) when a pushing force acts on the pipe. A connection structure for a pipe joint and a pipe, characterized by comprising : 2. The connection structure according to claim 1, wherein the following formula 1 is established between the width dimension (Ws) and the thickness dimension (Ts) in the cross section of the spring ring (S). .
0.8·Ts≦Ws≦2.0·Ts [Formula 1] 3. The connection according to claim 1 or 2, wherein the width dimension (Ws) of the spring ring (S) is set to the groove width dimension (W2) of the recessed circumferential groove (2) _by the following formula 2. Structure.
0.40·W ₂ ≦Ws≦0.70·W ₂ [Formula 2] 4. A connection structure according to claim 1, 2 or 3, wherein said concave circumferential groove (2) is formed by rolling .

Images