Pipe connection instrument and pipe connection method of removal prevention pipe joint

Abstract

To provide a pipe connection instrument which enables improvement of workability and safety in work for removing the pipe connection instrument in pipe connection work.SOLUTION: A pipe connection instrument 10 includes: a spacer 11 which is inserted into a cut part of a lock ring stored in a storage groove to expand the cut part; and a pair of levers 12, 13 which may rotate around a shaft part 16, intersect with each other, and are supported by the spacer 11. In the pair of levers 12, 13, string-like bodies 15 are respectively connected to one ends 12a, 13a of the levers 12, 13. When the one ends 12a, 13a are rotated in a spigot removal direction by tensile force applied by the string-like bodies 15, the other ends 12b, 13b of the lever which sandwich the shaft part 16 with the one ends 12a, 13a press an end surface of a socket in an insertion direction of the spigot.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an instrument for connecting pipes of an anti-disconnection pipe joint and a pipe connection method.

Background Art

[0002] As an anti-disconnection pipe joint, a pipe joint as shown in FIG. 12 is known. In this pipe joint, a lock ring 30 having a cut (cutting portion 31) at one location in the circumferential direction is accommodated in a groove 21 formed over the entire inner surface of a receiving port 20 of one pipe 1. The accommodated lock ring 30 is expanded by widening the cutting portion 31, and after an insertion port 40 having an engaging recess 41 formed at its tip is inserted into the receiving port 20, it is reduced in diameter (the virtual line in the figure). Thereby, the lock ring 30 engages with the engaging recess 41. The pipe joint prevents the pipe 1 from coming out due to the engagement between the lock ring 30 and the engaging recess 41 when an extraction force acts on the pipe. In the figure, 50 indicates a rubber ring for sealing.

[0003] The expansion and contraction of the lock ring 30 are performed by, for example, an instrument for connecting pipes described in Patent Document 1. The instrument for connecting pipes is typically a pipe connection instrument 90 having a U-shaped longitudinal section as shown in the blowing portion of FIG. 12. The pipe connection instrument 90 is inserted into the end of the receiving port 20 as shown in the upper figure of FIG. 12, and a spacer 90a, which is a portion along the inner surface of the receiving port 20, is inserted into the cutting portion 31 to expand the lock ring 30 and hold the expanded state. Then, the pipe connection instrument 90 is pulled in the separation direction of the insertion port 40 (arrow D9 in the figure), and the spacer 90a is pulled out from the cutting portion 31, so that it is separated from the end of the receiving port 20 and the lock ring 30 is reduced in diameter to its original state.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when removing the pipe connection device described in Patent Document 1, when the spacer is pulled out from the cutting portion, due to the large tightening force of the lock ring, the frictional force at the contact surface between the spacer and the cutting portion becomes large, and the tensile force required to pull out the spacer from the cutting portion becomes large. A large tensile force is applied in the separation direction of the insertion port by the operator, and the spacer is pulled out from the cutting portion at once.

[0006] Especially in recent years, as shown in the lower figure of Fig. 12, after the shield wall S is installed around the pipe 1, a construction method of sequentially inserting and connecting the pipe 1 from the rear has become common. In this case, since the gap between the outer surface of the pipe and the inner wall of the shield wall S is narrow, the operator cannot enter this gap, and the operator cannot directly touch the pipe connection device 90 and remove the pipe connection device 90 after inserting the pipe 1.

[0007] Therefore, as shown in the figure, a rope 90b or the like is connected to the pipe connection device 90, and the operator pulls the rope 90b from a distant place behind the inserted pipe to apply a tensile force in the separation direction of the insertion port 40 (arrow D9 in the figure). At this time, since the working space is narrow and the operator needs to apply a large tensile force to the pipe connection device 90 via the rope 90b only with arm strength, there is a problem that the workability of the removal work of the pipe connection device 90 is poor. In addition, when a large tensile force is applied using a rope 90b or the like from such a distant place and the spacer 90a is pulled out from the cutting portion 31 at once, the pipe connection device 90 may fly in the separation direction of the insertion port 40 due to the reaction, threatening the operator, and there is also a problem from the viewpoint of ensuring the safety of the work.

[0008] The present invention has been made in view of the above problems, and an object thereof is to provide a pipe connection device capable of improving the workability and safety of the work for removing the pipe connection device in the pipe connection work.

Means for Solving the Problems

[0009] To achieve the above object, the pipe connection device according to the first invention has a storage groove formed on the inner surface of the receiving port, accommodates a circumferentially split lock ring in the storage groove, with the cutting portion of the lock ring expanded in the circumferential direction to expand the diameter of the lock ring, inserts an insertion port having an engaging portion at the tip into the receiving port, and is a device used at the time of connecting a detachable pipe joint that, after insertion, reduces the diameter of the lock ring back to its original size so that it can engage with the insertion port engaging portion, a spacer that is inserted into the cutting portion of the lock ring accommodated in the storage groove to expand the cutting portion; a pair of levers that are rotatable about a shaft portion and cross each other and are supported by the spacer, and having, the pair of levers each have a string-like body connected to one end of the lever, and when the one end of the lever rotates in the detachment direction of the insertion port due to the tensile force applied by the string-like body, the other end of the lever that sandwiches the shaft portion between it and the one end presses the end face of the receiving port in the insertion direction of the insertion port.

[0010] According to this, in the pipe connection device, the tensile force applied to one end of the lever is transmitted to the spacer as a pulling force that pulls out the spacer in the direction of disengagement of the insertion port, with the portion where the other end of the lever presses the end face of the receiving port as the fulcrum, via the shaft portion. When the transmitted pulling force resists the frictional force between the spacer and the cutting portion, the spacer is pulled out from the cutting portion and disengaged. At this time, since the shaft portion is disposed between the one end portion and the other end portion, the pulling force becomes larger than the tensile force according to the principle of the lever. That is, the pipe connection device can pull out the spacer from the cutting portion with a smaller tensile force than before. Thereby, the pipe connection device can improve the workability during the removal work of the pipe connection device. Further, in the pipe connection device, since the spacer can rotate around the shaft portion, the spacer is gradually displaced in the direction of disengagement of the insertion port while being sandwiched by the cutting portion and swinging, and is pulled out. Therefore, the pipe connection device requires less recoil when the spacer is pulled out from the cutting portion than when the spacer is pulled out all at once as in the conventional case. Thereby, since the pipe connection device does not fly toward the operator when the spacer is pulled out from the cutting portion, the work safety can also be improved.

[0011] Each of the pair of levers of the pipe connection device according to the second invention has a roller rotatably supported at the other end. The other end presses the end face of the receiving port via the roller.

[0012] According to this, in the pipe connection device, when the other end of the lever presses the end face of the receiving port via the roller and the lever rotates and the other end moves the end face of the receiving port, the friction generated by the contact between the other end and the end face of the receiving port is made into rolling friction, so that the frictional force generated at this time can be reduced. Therefore, the pipe connection device can efficiently transmit the tensile force applied to the one end as a pulling force to the spacer by reducing the loss of the force generated by the contact between the other end and the end face of the receiving port. As a result, the pipe connection device can improve the workability during the removal work of the pipe connection device.

[0013] The pipe connection device according to the third invention further includes an outer plate provided to face the spacer in the pipe diameter direction. The outer plate is connected to the spacer via a shaft portion, and the end portion of the receiving port is inserted between the outer plate and the spacer.

[0014] According to this, in the pipe connection device, the end portion of the receiving port is inserted between the spacer and the outer plate, and the spacer and the outer plate sandwich the end portion of the receiving port, thereby restricting the movement of the spacer in the pipe diameter direction. That is, the pipe connection device prevents the spacer inserted into the cutting portion from moving in the pipe diameter direction and inadvertently detaching from the cutting portion before being pulled out in the detachment direction of the insertion port, that is, the pipe connection device from falling off the receiving port. As a result, the pipe connection device can improve the workability during the removal work of the pipe connection device.

[0015] In the pair of levers of the pipe connection device according to the fourth invention, the length from the shaft portion to one end portion is larger than the length from the shaft portion to the other end portion.

[0016] According to this, the pipe connection device can efficiently amplify the tensile force applied to one end portion to obtain a pulling force for pulling out the spacer from the cutting portion. That is, the spacer of the pipe connection device is pulled out from the cutting portion with a smaller tensile force than before. Thereby, the pipe connection device can improve the workability during the removal work of the pipe connection device.

[0017] The spacer of the pipe connection device according to the fifth invention has a bent portion that bends outward in the pipe diameter direction at the end portion in the detachment direction of the insertion port.

[0018] According to this, after the pipe connection device is attached to the receiving port, in the process where the insertion port is inserted into the receiving port, since the spacer has a bent portion, the end portion of the insertion port to be inserted is guided to the inner side in the pipe diameter direction of the bent portion. Therefore, the pipe connection device prevents the insertion port from not being inserted into the receiving port by the end portion of the insertion port contacting the end portion on the separation direction side of the spacer. As a result, the pipe connection device can improve the workability during the device removal operation.

[0019] In the pipe connection method according to the sixth invention, a storage groove is formed on the inner surface of the receiving port. In a separation prevention pipe in which a circumferentially divided locking ring is stored in the storage groove. A spacer that is inserted into the cut portion of the locking ring stored in the storage groove to expand the cut portion, A pair of levers that are rotatable about a shaft portion and intersect each other and are supported by the spacer, And a string-like body connected to one end portion of each lever A pipe connection method of a separation prevention pipe joint using a pipe connection device having the above, The spacer is inserted into the cut portion of the locking ring to expand the cut portion and expand the diameter of the locking ring. With the locking ring expanded in diameter, an insertion port having an engaging portion at the tip is inserted into the receiving port. When a tensile force is applied to one end portion of a pair of levers via a string-like body and the levers rotate in the separation direction of the insertion port, The other end portion of the lever sandwiching the shaft portion between it and the one end portion presses the end face of the receiving port in the insertion direction of the insertion port, so that the spacer is pulled out from the cut portion, and the locking ring is reduced in diameter to its original state and engages with the engaging portion of the insertion port.

[0020] According to this, the pipe connection method is such that the tensile force applied to one end of the lever is transmitted as a pulling force that pulls out the spacer in the direction of disengagement from the insertion port with the portion where the other end of the lever presses against the receiving port end face as a fulcrum through the shaft portion. When the transmitted pulling force resists the frictional force between the spacer and the cutting portion, the spacer is pulled out from the cutting portion. At this time, by arranging the shaft portion between one end and the other end, the pulling force becomes larger than the tensile force according to the principle of the lever. That is, since the spacer is pulled out from the cutting portion with a smaller tensile force than before, the pipe connection method can improve the workability of the instrument removal work during the pipe connection work. Also, in the pipe connection method, since the spacer can rotate around the shaft portion, the spacer is gradually pulled out from the cutting portion while being applied with a pulling force. Therefore, the pipe connection method requires less recoil when the spacer is pulled out from the cutting portion than when the spacer is pulled out all at once as in the prior art. Therefore, since the pipe connection instrument does not fly towards the operator when the spacer is pulled out from the cutting portion, the pipe connection method can also improve the work safety.

Effects of the Invention

[0021] According to the present invention, the pipe connection instrument can improve the workability and safety during the work of removing the pipe connection instrument.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11A

Figure 11B

Figure 12

Mode for Carrying Out the Invention

[0023] [Regarding the Configuration of the Pipe Connection Device] Hereinafter, the pipe connection device 10 according to the embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description will not be repeated. Also, in the following description, terms indicating positions or directions such as "upper" and "lower" may be used. These terms are used for convenience in order to facilitate the understanding of the embodiment, and are not limited to the positions or directions during actual implementation.

[0024] First, with reference to FIG. 1, the connection operation of the anti-disconnection pipe using the pipe connection device 10 according to the embodiment of the present invention will be described. FIG. 1 is a cross-sectional view showing the connection operation of the anti-disconnection pipe using the pipe connection device according to the embodiment of the present invention. As shown in FIG. 1, hereinafter, the insertion direction of the insertion port 40 will be simply referred to as the "insertion direction", and the disconnection direction of the insertion port 40 will be simply referred to as the "disconnection direction". Also, the direction facing the outside in the pipe diameter direction will be simply referred to as the "outside in the pipe diameter direction", and the direction facing the inside in the pipe diameter direction will be simply referred to as the "inside in the pipe diameter direction".

[0025] As shown in FIG. 1, the pipe connection device 10 is attached to the end of the receiving port 20, and the spacer 11 is inserted into the cutting portion 31 of the locking ring 30 to expand the cutting portion 31 and expand the diameter of the locking ring 30, and hold the expanded state. In the figure, 50 indicates a rubber ring for sealing.

[0026] On the other hand, the insertion port 40 is inserted into the receiving port 20. Then, the spacer 11 is pulled out from the cutting portion 31 and the pipe connection device 10 is removed from the end face of the receiving port 20, so that the diameter of the locking ring 30 is reduced. At this time, a tensile force is applied to the pipe connection device 10 in the disconnection direction (arrow D9 in the figure) via the string-like body 15 connected to the pipe connection device 10, and the spacer 11 is pulled out from the cutting portion 31. The reduced-diameter locking ring 30 engages with the engaging concave portion 41. Thereby, when an extraction force acts on the pipe joint, the engagement between the locking ring 30 and the engaging concave portion 41 prevents the pipe 1 from being pulled out.

[0027] Next, with reference to FIGS. 2 to 4, the configuration of the pipe connection device 10 according to the embodiment of the present invention will be described. FIG. 2 is an external view of the pipe connection device 10 according to the embodiment of the present invention. FIG. 3 is a top view of the pipe connection device 10. FIG. 4 is a cross-sectional view taken along line A-A of FIG. 3.

[0028] As shown in FIGS. 2 to 4, the pipe connection device 10 includes a plate-shaped spacer 11 extending in the axial direction and circumferential direction of the pipe 1 (see FIG. 1), an outer plate 17 provided to face the spacer 11 on the outer side in the pipe diameter direction, a shaft portion 16 connecting the spacer 11 and the outer plate 17, and a pair of long plate-shaped levers 12, 13 supported by the shaft portion 16 and provided in an overlapping manner at the end portion of the spacer 11 on the detachment direction side.

[0029] As described above, the pipe connection device 10 is attached to the end portion of the socket 20 (see FIG. 1). At this time, the pipe connection device 10 sandwiches the end portion of the socket 20 in the pipe diameter direction between the spacer 11 and the outer plate 17.

[0030] The spacer 11 has a base portion 11a and an insertion portion 11b that is continuous with the base portion 11a in the insertion direction and is inserted into the cutting portion 31 (see FIG. 1) of the locking ring 30.

[0031] Specifically, the shaft portion 16 is a bolt extending in the pipe diameter direction. The shaft portion 16 rotatably supports the pair of levers 12, 13 around the shaft portion 16.

[0032] Specifically, the pair of levers 12, 13 are an outer lever 12 on the outer side in the pipe diameter direction and an inner lever 13 on the inner side in the pipe diameter direction. The pair of levers 12, 13 have one end portion 12a, 13a on the detachment direction side, the other end portion 12b, 13b on the insertion direction side, and bearing portions 12c, 13c provided between the one end portion 12a, 13a and the other end portion 12b, 13b.

[0033] A string-like body 15 is connected to each of the one end portions 12a, 13a. The string-like body 15 is typically a rope, and in this embodiment, it is a nylon rope. The other end portions 12b, 13b rotatably support the roller 14. In particular, as shown in FIG. 4, the bearing portions 12c, 13c have through holes 12d, 13d provided in the respective levers 12, 13 and nuts 12e, 13e. Each bearing portion 12c, 13c has the nut 12e, 13e fixed to the levers 12, 13 by welding or the like so that the screw hole of the nut 12e, 13e communicates with the through hole 12d, 13d on the outer side in the pipe diameter direction of the outer lever 12 and on the inner side in the pipe diameter direction of the inner lever 13, respectively.

[0034] The shaft portion 16 has the bearing portions 12c and 13c of the respective levers 12 and 13 screwed thereto, and rotatably supports the respective levers 12 and 13. By rotating about the shaft portion 16, the respective levers 12 and 13 intersect each other.

[0035] The rollers 14 are typically resin rollers incorporating bearings, and the bearing inner rings of the respective rollers 14 and 14 are supported on the outer side in the pipe diameter direction of the other end portion 12b and the inner side in the pipe diameter direction of the other end portion 13b, respectively. That is, the respective rollers 14 and 14 are disposed between the outer lever 12 and the outer plate 17 and between the inner lever 13 and the spacer 11.

[0036] The outer plate 17 is connected to the spacer 11 via a plurality of connecting portions 18 in addition to the shaft portion 16.

[0037] The connecting portions 18 are disposed on the rotation orbits of the respective levers 12 and 13. Thereby, the rotation of the respective levers 12 and 13 by a predetermined angle or more is restricted by the connecting portions 18.

[0038] The spacer 11 has a bent portion 11c provided at the end portion on the detachment direction side of the base portion 11a. In particular, as shown in FIG. 4, the bent portion 11c is formed by curving or bending the end portion on the detachment direction side of the base portion 11a outward in the pipe diameter direction.

[0039] Note that the circumferential length of the insertion portion 11b in the pipe circumferential direction may be configured such that a plurality of portions having different lengths are continuously provided in the pipe axis direction in a stepped manner so as to be able to cope with a plurality of pipes having different diameters. When the diameters of the pipes are different, the diameters of the lock rings 30 accommodated in the accommodation grooves 21 are also different, so the required amount of diameter expansion of the lock rings is different. Therefore, it is necessary to appropriately set the circumferential length of the insertion portion 11b in the pipe circumferential direction in response to the different lengths of the appropriate cutting portions 31.

[0040] With the above configuration, the pipe connection device 10 supports a pair of levers 12 and 13 between the spacer 11 and the outer plate 17 so as to be rotatable about the shaft portion 16 and cross each other. When a force is applied to one end portion 12a and 13a of each of the pair of levers 12 and 13, the pair of levers 12 and 13 rotate about the shaft portion 16.

[0041] Specifically, when a force in the insertion direction is applied to one end portion 12a and 13a of each of the pair of levers 12 and 13 from the state shown in FIGS. 2 to 4, each one end portion 12a and 13a rotates in the insertion direction, and each lever 12 and 13 is folded from the intersecting state shown in FIGS. 2 to 4 so that each one end portion 12a and 13a approaches each other end portion 13b and 12b as shown in FIG. 6. Then, when the rotation of each lever 12 and 13 is restricted with the connecting portions 18 and 18 as stoppers, the rotation of each lever 12 and 13 ends, and at this time, each lever 12 and 13 is in a state of linearly overlapping in the circumferential direction of the pipe (hereinafter, this state is referred to as the "closed state").

[0042] On the other hand, when a tensile force is applied to one end portion 12a and 13a of each of the pair of levers 12 and 13 in the separation direction from the state shown in FIGS. 2 to 4, each one end portion 12a and 13a rotates in the separation direction, and each lever 12 and 13 is folded from the intersecting state shown in FIGS. 2 to 4 so that each one end portion 12a and 13a approach each other and each other end portion 12b and 13b approach each other as shown in FIG. 7. Then, when the string-like bodies 15 and 15 connected to each one end portion 12a and 13a are substantially overlapped, the rotation of each lever 12 and 13 ends, and at this time, the rollers 14 and 14 of each other end portion 12b and 13b are in a state of being close to each other (hereinafter, this state is referred to as the "open state").

[0043] [Regarding the operation of the pipe connection device during the removal operation of the device] Next, with reference to FIGS. 5 to 8, the operation of the pipe connection device 10 during use will be described. FIG. 5 is a cross-sectional view showing the state in which the pipe connection device 10 is attached to the end of the receiving port 20. FIG. 6 is a cross-sectional view taken along the line B-B of FIG. 5. FIG. 7 is a view showing the state in which the pipe connection device 10 is removed from the end of the receiving port 20 in the cross-sectional view taken along the line B-B of FIG. 5. FIG. 8 is a cross-sectional view showing the state in which the pipe connection device 10 is removed from the end of the receiving port 20.

[0044] From FIGS. 5 and 6, the closed pipe connection device 10 attached to the end of the receiving port 20 sandwiches the end of the receiving port 20 in the pipe diameter direction between the spacer 11 and the outer plate 17. The insertion portion 11b of the spacer 11 is inserted into the cutting portion 31 of the lock ring 30, and the lock ring 30 is expanded by expanding the cutting portion 31. At this time, the rollers 14, 14 at the other ends 12b, 13b of the respective levers 12, 13 abut against the end face of the receiving port 20. Then, as shown in FIGS. 6 and 7, one ends 12a, 13a of the respective levers 12, 13 to which a tensile force is applied in the separation direction (arrow D1 in the figure) via the string-like body 15 rotate in the separation direction (arrow D2 in the figure) and change from the closed state to the open state. As a result, the rollers 14, 14 at the other ends 12b, 13b of the respective levers 12, 13 press the end face of the receiving port 20 in the insertion direction (arrow D3 in the figure).

[0045] Although details will be described later, when the roller 14 presses the end face of the receiving port 20, a pulling force is generated in the separation direction on the shaft portion 16 as a reaction force (arrow D4 in the figure). The spacer 11 is displaced in the separation direction by the pulling force resisting the frictional force at the contact surface between the cutting portion 31 and the insertion portion 11b.

[0046] At this time, as each one end portion 12a, 13a rotates in the detachment direction (arrow D2 in the figure), each other end portion 12b, 13b rotates in the insertion direction, so that each other end portion 12b, 13b is moved in a direction approaching each other on the end surface of the receiving port 20 via each roller 14, 14. At this time, in the pipe connection device 10, the friction generated at the contact surface can be made into rolling friction by the contact between each other end portion 12b, 13b and the end surface of the receiving port 20 via each roller 14, 14. Thereby, the pipe connection device 10 can reduce the frictional force generated as the other end portions 12b, 13b move, and as a result, the tensile force can be efficiently transmitted to the shaft portion 16 to be a pulling force.

[0047] As shown in FIG. 7, when the pipe connection device 10 is in an open state, the insertion portion 11b of the spacer 11 is pulled out from the cutting portion 31 of the lock ring 30 and detached. Thereby, as shown in FIG. 8, the lock ring 30 is reduced in diameter and engaged with the engaging concave portion 41 of the insertion port 40.

[0048] Also, as particularly shown in FIG. 5, since the pipe connection device 10 has the bent portion 11c in the spacer 11, when the insertion port 40 is inserted into the receiving port 20 with the pipe connection device 10 attached to the receiving port 20, the end portion of the insertion port 40 is guided to the inside in the pipe diameter direction of the bent portion 11c. Thereby, the pipe connection device 10 can prevent the end portion of the insertion port 40 from contacting the end portion on the detachment direction side of the spacer 11 and the insertion port 40 from not being inserted into the receiving port 20.

[0049] [Regarding the acting force on the pipe connection device during the device removal operation] Next, referring to FIG. 9, the acting forces on the pipe connection tool 10 during the removal operation of the tool will be described. FIG. 9 is a diagram showing the acting forces on the pipe connection tool 10 during the removal operation of the tool. In FIG. 9, the above-described embodiment is shown in a simplified manner. Specifically, the outer plate 17 is omitted, the outer lever 12 of the two levers is shown by a solid line, and the inner lever 13 is shown by a virtual line. The tensile forces acting on each one end portion 12a, 13a by pulling the string-like body 15 are set as T1 and T2, and the pulling-out forces received by the shaft portion 16 from each lever 12, 13 are set as P1 and P2. Each acting force shows only the component in the detachment direction. It is assumed that the acting points of each one end portion 12a, 13a, each other end portion 12b, 13b, and the shaft portion 16 are arranged on the same line.

[0050] In FIG. 9, let the "length from the one end portion 12a to the other end portion 12b" be A, the "length from the shaft portion 16 to the other end portion 12b" be B, and it is assumed that the frictional force generated between the roller 14 and the end face of the receiving port 20 is small and is ignored. At this time, considering the balance of the moment around the other end portion 12b, the product of the tensile force T1 and the length A is equal to the product of the pulling-out force P1 and the length B. Therefore, the pulling-out force P1 is the product of the tensile force T1 multiplied by "the ratio of A to B (hereinafter referred to as the lever ratio): A / B". The same applies to the relationship between the pulling-out force P2 and the tensile force T2 in the lever 13.

[0051] That is, in FIG. 9, in the relationship between the tensile forces T1, T2 applied to the one end portions 12a, 13a and the pulling-out forces P1, P2 acting on the shaft portion 16, the principle of the lever can be applied with the portions where the respective rollers 14, 14 press the end face of the receiving port 20 (hereinafter referred to as "roller fulcrums F1, F2") as fulcrums, the one end portions 12a, 13a as the force points, and the shaft portion 16 as the acting points.

[0052] Specifically, in this embodiment, for example, the lever ratio (A / B) is 2.4. Therefore, if the sum of the extraction forces P1 and P2 is P, and the sum of the tensile forces T1 and T2 is T, the extraction force P is 2.4 times the tensile force T. That is, in the conventional pipe connection device, in order to obtain the extraction force P, at least a tensile force T of the same magnitude as the extraction force P had to act. However, for the pipe connection device 10, in order to obtain the extraction force P, a tensile force T of 42% of the magnitude of the extraction force P may act. Thereby, in the pipe connection device 10, the spacer 11 can be pulled out from the cut portion 31 of the lock ring 30 and removed with a smaller tensile force T than before.

[0053] In addition, for example, when the lever ratio is set to be greater than 2, the length from one end portion 12a to the shaft portion 16: A - B is made greater than the length from the shaft portion 16 to the other end portion 12b: B. That is, when the inequality "A - B > B" indicating the condition at this time is transformed, "A / B (lever ratio) > 2" is obtained, and the lever ratio becomes greater than 2. Thereby, the pipe connection device 10 can make the tensile force T required to obtain the extraction force P smaller than 50% of the extraction force P. Therefore, the pipe connection device 10 can be removed with a smaller tensile force T than before.

[0054] Further, the pipe connection device 10 is stably supported at two points in the pipe diameter direction and the pipe circumferential direction by the respective roller fulcrums F1 and F2, and the respective tensile forces T1 and T2 and the respective extraction forces P1 and P2 act.

[0055] On the other hand, as shown in FIG. 10, in the conventional pipe connection device 90, when a tensile force T is applied via the rope 90b, the tensile force T acts directly on the contact portion between the spacer 90a and the cut portion 31 without passing through a roller fulcrum or the like. FIG. 10 is a diagram showing a state when a tensile force T is applied to the conventional pipe connection device 90.

[0056] As a result, when the pipe connection fitting 90 is subjected to a tensile force, it rotates inward in the pipe diameter direction with the contact surface between the spacer 90a and the cutting portion 31 as a fulcrum (arrow D10 in the figure), and tilts with respect to the end face of the socket 20 within the gap from the end of the socket 20 in the pipe diameter direction. There was a possibility that the inner surface of the pipe connection fitting 90 and the outer surface of the end of the socket 20 would come into local contact in region CA and generate frictional force in region CA. On the other hand, as shown in FIG. 9, the pipe connection fitting 10 is stably supported at two points in the pipe diameter direction and the pipe circumferential direction by the respective roller fulcrums F1 and F2, and the respective tensile forces T1 and T2 and the respective pulling-out forces P1 and P2 act thereon, thereby suppressing the inclination of the pipe connection fitting 10 with respect to the end face of the socket 20. As a result, the pipe connection fitting 10 is less likely to come into local contact with the outer surface of the end of the socket 20, and the generation of frictional force is suppressed.

[0057] Furthermore, since the shaft portion 16, which is the acting point of the pulling-out force P, supports the respective bearing portions 12c and 13c by screw portions, the shaft portion 16 and the respective bearing portions 12c and 13c are rotatable relative to each other. Therefore, as shown in FIGS. 11A and 11B, in the process of the insertion portion 11b of the spacer 11 being pulled out from the cutting portion 31 of the lock ring 30, the pipe connection fitting 10 can take a rotational behavior with the spacer 11 centered on the shaft portion 16. FIGS. 11A and 11B are diagrams showing the rotational behavior of the pipe connection fitting 10 during the fitting removal operation. FIG. 11A shows a state in which the spacer 11 rotates in one direction (direction D6 in the figure) centered on the shaft portion 16, and FIG. 11B shows a state in which the spacer 11 rotates in the other direction (direction D7 in the figure).

[0058] As a result, in the process of the insertion portion 11b of the pipe connection fitting 10 being pulled out from the cutting portion 31, the pipe connection fitting 10 can alternately repeat the rotation of arrow D6 in FIG. 11A and the rotation of arrow D7 in FIG. 11B to gradually displace the spacer 11 in the separation direction while swinging it around the shaft portion 16.

[0059] As described above, the pipe connection device 10 "applies the principle of a lever to reduce the tensile force T" and also "suppresses the inclination with respect to the end face of the receiving port 20 to suppress the generation of frictional force between the receiving port 20 and the end face". As a result, compared with the case of using the conventional pipe connection device 90, the spacer 11 can be pulled out from the cutting portion 31 with a small tensile force T, and the pipe connection device 10 can be removed from the receiving port 20. As a result, the pipe connection device 10 can improve the workability in the operation of removing the pipe connection device. Further, by "displacing the spacer 11 in the separation direction while swinging", the insertion portion 11b of the pipe connection device 10 is gradually pulled out from the cutting portion 31. Thus, unlike the case where the conventional pipe connection device 90 is pulled out all at once, the pipe connection device 10 requires less recoil when pulled out. Therefore, since there is no risk that the pipe connection device 10 will fly towards the operator when the spacer 11 is pulled out from the cutting portion 31, as a result, the pipe connection device 10 can also improve the safety of the operation.

[0060] [Tensile Force Measurement Results] In the actual operation of removing the pipe connection device, the tensile force T when using the conventional pipe connection device 90 and the pipe connection device 10 according to the present invention was compared. As a result, the tensile force T when using the conventional pipe connection device 90 was 15 - 20 kgf, whereas the tensile force T when using the pipe connection device 10 according to the present invention was 3 - 5 kgf. That is, the pipe connection device 10 can significantly reduce the tensile force T required in the operation of removing the device, and as a result, can significantly improve the workability in the operation of removing the device.

[0061] The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the above-described embodiments, and can be implemented in various forms without departing from the gist thereof. The drawings schematically show each component mainly for easy understanding, and the thickness, length, number, interval, etc. of each illustrated component are different from the actual ones for convenience of drawing preparation. In addition, the materials, shapes, dimensions, etc. of each component shown in the above embodiments are examples and are not particularly limited, and various changes can be made without substantially departing from the configuration of the present invention.

Explanation of Reference Numerals

[0062] 10 Appliance for Pipe Connection 11 Spacer 11a Base 11b Insertion Portion 11c Bent Portion 12 Outer Lever 13 Inner Lever 12a, 13a One End Portion 12b, 13b Other End Portion 12c, 13c Bearing Portion 14 Roller 15 String-like Body 16 Shaft Portion 17 Outer Plate 18 Connecting Portion 20 Receiving Port 21 Storage Groove 30 Lock Ring 31 Cutting Portion 40 Insertion Port 41 Engaging Portion

Claims

1. A storage groove is formed on the inner surface of the socket, A lock ring is placed in the groove, and is split in the circumferential direction. The cut portion of the lock ring is expanded in the circumferential direction to expand the diameter of the lock ring, and a socket having an engagement portion at its tip is inserted into the socket, A tool used when connecting a detachment prevention pipe joint in which the lock ring is reduced in diameter to its original state after insertion so that it can engage with the insertion port engagement portion, a spacer that is inserted into the cut portion of the lock ring stored in the storage groove to widen the cut portion; A pair of levers rotatable about a shaft portion and supported by a spacer so as to cross each other; having The pair of levers each have a string-like body connected to one end of the lever, When one end of the lever rotates in the direction of removing the insertion port due to the tensile force applied by the string-like body, the other end of the lever, which sandwiches the shaft between the one end and the lever, presses the end face of the receiving port in the direction of inserting the insertion port. A pipe connecting device characterized by:

2. The pair of levers each have a roller rotatably supported at the other end thereof, The other end presses the end face of the socket via a roller.

2. The pipe connecting device according to claim 1 .

3. Further, an outer plate is provided opposite the spacer in the pipe radial direction, The outer plate is connected to the spacer via the shaft portion, and the end of the socket is inserted between the outer plate and the spacer.

3. The pipe connecting device according to claim 1 or 2.

4. The length of each of the pair of levers from the shaft portion to one end is greater than the length from the shaft portion to the other end.

3. The pipe connecting device according to claim 1 or 2.

5. The spacer has a bent portion at the end in the removal direction of the insertion port that is bent toward the outside in the pipe diameter direction.

3. The pipe connecting device according to claim 1 or 2.

6. A storage groove is formed on the inner surface of the socket, In a detachment prevention tube in which a lock ring is housed in a housing groove, the lock ring is housed in a single circumferential slot. a spacer that is inserted into the cut portion of the lock ring stored in the storage groove to widen the cut portion; A pair of levers rotatable about a shaft portion and supported by a spacer while crossing each other; A string-like body connected to one end of each lever; A method for connecting a pipe to a non-detachable pipe joint using a pipe connecting tool having the following features: A spacer is inserted into the cut portion of the lock ring to widen the cut portion and expand the diameter of the lock ring; With the lock ring expanded, the insertion port having an engagement portion at the tip is inserted into the receiving port, When one end of the pair of levers is applied with a tensile force via the string-like body and rotates in the direction of removing the insertion port, The other end of the lever, which holds the shaft between itself and one end, presses the end face of the socket in the direction of insertion of the socket, pulling the spacer out of the cut section and shrinking the lock ring back to its original diameter to engage with the socket engagement section. A pipe connecting method for a detachment-prevention pipe joint.

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