JP2008115911A - Packing fastening device in pipe coupling - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a packing fastening device in a pipe coupling capable of connecting couplings without using a bolt and a nut. <P>SOLUTION: This fastening device is formed by arranging a packing in a space formed of a cylindrical pipe body outside surface and a conical coupling inner surface. The coupling is constituted of a body 14 and a flange 15. An engaging part 16 is formed on the outside surface of the body, and an engaging mating part 17 is formed on the inner surface of the flange. The coupling is movable. At least two cylindrical cams 18 inclined so as to move the coupling to the pipe body axis by engagement are provided on the outside surface of the body. The engaging mating member 17 is constituted by arranging at least two mating parts 20 engaged with the cylindrical cams on the flange inner surface. When rotating the flange in the peripheral direction to the body, a rolling bearing is constituted by being interposed between a pipe body outside surface 24 and the inner surface 26 of the flange. A plurality of rotatable rigid body balls 27 capable of biting in the pipe body outside surface and the inner surface of the flange is substantially uniformly arranged in the peripheral direction of the packing. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an apparatus for fastening a packing by moving the joint in the axial direction of the pipe body in a pipe joint in which the packing is arranged in a space formed by the outer surface of the cylindrical pipe body and the inner surface of the conical joint. It is.

  Conventional water supply and drainage pipe joints that have been used for water supply and drainage facilities in buildings are, for example, a joint body and a fastening rod made of rubber for preventing water leakage as seen in the devise of Japanese Utility Model Laid-Open No. 7-19690. It is tightened and connected by several bolts and nuts through the packing. The number of bolts is usually 2 when the connecting steel pipe has a diameter of 2 inches, or 3 or 4 when the diameter is 3 inches or more.

  However, in building structures that are becoming taller, the infrastructure space of buildings such as water supply and drainage pipes, power distribution, and communication lines has become denser in response to demands for expanding the effective space, thereby narrowing the space around the pipes. Therefore, downsizing of pipe joints and the like is required. In the future, as the number of workers from overseas increases, simplification of joint work is required, and higher connection reliability is required. In addition, there is a need to improve the earthquake resistance accompanying the increase in the number of layers, and as a whole, shortening the work time, making the work more economical, and ensuring reliability are issues.

  On the other hand, in the above-described conventional method, for example, six bolts and nuts are used at both ends of the joint, and for the fastening, an operation of rotating a spanner, a torque wrench, or the like from three directions is used. Therefore, it becomes very difficult work in a small space and takes time. In addition, when using rubber packing, it is difficult in the field to comply with the specified torque of tightening, and damage to the joint due to excessive tightening, water leakage due to excessive tightening, and accidents of pipe removal have occurred. For this reason, inspection time after construction is required, and the total cost tends to increase.

ACT 7-19690 Utility model registration No. 3099370

  The present invention has been made paying attention to the above points, and an object of the present invention is to provide a packing tightening device in a pipe joint that can connect the pipe joint without using bolts and nuts. Another object of the present invention is to provide a packing tightening device in a pipe joint that does not require an excessive space around the joint for tightening the joint. Another object of the present invention is to provide a packing tightening device in a pipe joint that can easily manage the tightening torque of the packing.

  In order to solve the above-described problems, the present invention arranges a packing in a space formed by a cylindrical tube outer surface and a conical joint inner surface, and moves the joint in the axial direction of the tube to tighten the packing. As a device for this, a pipe joint is constituted by a main body part and a flange part positioned in the axial direction of the pipe body, and an engaging part is provided on the outer surface of the main body part, while engaging with the inner surface of the flange part. A mating portion is provided, and the engaging portion is at least two cylindrical cam portions inclined with respect to the axial direction of the tubular body so as to move the joint in the axial direction of the tubular body by engagement with the engaging mating portion. On the outer surface of the main body portion, and the engaging counterpart portion has at least two counterpart portions on the inner surface of the flange portion that engage with the cylindrical cam portion, and the engaging portion and the engaging counterpart portion When rotating the flange portion in the circumferential direction with respect to the main body portion under engagement, A rolling bearing is interposed between the outer surface of the body and the inner surface of the flange portion to move the body portion in the axial direction of the tube body, thereby tightening the packing, and after tightening, the outer surface of the tube body and the flange portion A plurality of rotatable hard spheres that can bite into the inner surface of the packing are arranged substantially uniformly in the circumferential direction of the packing.

  A packing tightening device for a pipe joint according to the present invention is arranged by arranging packing in a space formed by an outer surface of a cylindrical tube body and an inner surface of a conical joint, and moving the joint in the axial direction of the tube body. The packing is pressed against the outer surface of the tube body by tightening to perform a water sealing action and enhances the connection force. This packing performs the same function as the conventional rubber packing described above, but the materials that can be used include not only the resin that belongs to rubber, but also the resin that is used for packing, even if it is not a rubber. Shall be.

  In the present invention, the pipe joint is divided into a main body portion and a flange portion positioned in the axial direction of the main body portion, and an engaging portion is provided on the outer surface of the main body portion, while the inner surface of the flange portion is provided. Is provided with an engagement partner part to be engaged with the engagement part. As the engagement portion, at least two cylindrical cam portions that are inclined with respect to the axial direction of the tube body so that the main body portion is moved in the axial direction of the tube body by engagement with the mating counterpart portion. At least two mating portions that are engaged with the cylindrical cam portion are provided on the inner surface of the joint. In other words, the engaging portion and the mating mating portion are coupling means including a function of converting the rotational motion of the flange portion constituting the joint in the circumferential direction into the linear motion in the axial direction of the tubular body constituting the joint. For this purpose, the configuration of the cylindrical cam portion is used. By determining the amount of linear motion in the axial direction, the degree to which the packing is tightened can be adjusted, thereby making it possible to easily manage the tightening torque.

  This type of coupling means is similar to a so-called bayonet type coupling structure represented by, for example, a lens attaching / detaching means in an interchangeable lens camera. The mating parts to be arranged are at least two places or three places or more and are arranged almost evenly. The cylindrical cam portion can be provided on the cylindrical surface of the outer surface of the main body portion, for example, as a rising portion outward in the radial direction. The mating portion that can be engaged with the cylindrical cam portion can be provided on the inner surface of the flange portion, for example, as a radially inwardly raised portion. However, on the cylindrical surface of the outer surface of the main body portion, for example, a groove inclined with respect to the axial direction may be provided as a cylindrical cam portion, and a pin engageable with the groove may be provided on the inner surface of the flange portion as a counterpart portion. The form can be arbitrarily set.

  The cylindrical cam portion provided on the outer surface of the main body portion can be provided with a stop portion for determining the final position of engagement with the mating portion provided on the inner surface of the flange portion. The stop portion can be provided in a protruding shape that stops the counterpart portion from returning along the inclined cylindrical cam portion. Since such a stop portion is provided on the cylindrical cam in a protruding shape directed in the axial direction, it does not come into contact with the mating portion before engaging, and the engagement proceeds in the axial direction to the main body portion of the joint. Is moved into an engaged state. The flange portion desirably has a cap nut-like structure having a mating portion on the inner surface, and preferably has an anti-slip on the outer surface that serves as a clue when rotating the flange portion.

  When the flange portion is rotated in the circumferential direction relative to the main body portion with the engagement portion and the engagement counterpart portion engaged, the axial direction of the tube body is interposed between the outer surface of the tube body and the inner surface of the flange portion. A rolling bearing for moving the main body part is configured to tighten the packing, and after tightening, a plurality of rotatable rigid spheres that can bite into the outer surface of the main body part and the inner surface of the flange part. Arrange almost evenly in the circumferential direction. In other words, the rigid sphere acts as a rolling element that reduces rolling friction when the joint flange portion is rotated in the circumferential direction with respect to the pipe body, and bites that prevent the pipe body from being pulled out once it has been tightened. It will act as a member.

  In order to enhance the function as a biting member that prevents the tube body from being pulled out, in the present invention, when an external force acting in the direction of pulling out the joint is applied to the tube body, the rigid sphere moves around the axis in the circumferential direction of the tube body. As a condition for rotating and moving in the pulling direction and causing the rigid sphere to rotate by the external force in the pulling direction, the included angle 2α formed by the tube outer surface and the joint inner surface in the space is set to 17 ° ± 7 °, In addition, it is desirable to configure the outer shape of the rigid sphere to be at least twice the minimum gap Δg between the outer surface of the main body portion and the inner surface of the flange portion. With this configuration, when a pulling force is applied to the tube body, and the force increases, the frictional force increases in proportion to the force, so that the tube body is continuously gripped until it is broken.

Such a tube body pull-out preventing device is described in detail as a self-balancing type pull-out preventing device in Japanese Patent Application No. 2005-302002 preceding the present invention, and the invention can be applied to the present invention. Only the main part will be described here. In FIG. 7, when a pulling force ΔF is applied in the axial direction of the tubular body, the rotational torque determined by the respective friction coefficients μ1 and μ2 is exerted on the rigid sphere that is a rotating body sandwiched between the tubular body and the flange portion. Occurs and moves by Δl in the same direction as the pulling force ΔF. When the center O of the hard sphere moves to O ′, Δr = Δlsin α of the radius of the hard sphere bites into the cylindrical tube outer surface and the substantially conical flange inner surface, and the pressure ΔR is applied to each surface. generate. This is because when the wedge is driven with a force ΔK into the space ABC having a substantially wedge-shaped cross section,
ΔK = 2ΔR (sin α + μ cos α),
Is the same as In the case of the present invention, the force ΔK is not directly applied to the rigid sphere, but the rigid sphere, which is the rotating body, moves toward the inside of the wedge-shaped cross-sectional space by the rotational torque generated by the pulling force ΔF applied to the tube. This is because it can be regarded as equivalent to being typed in.

That is, if a and b are constants,
Δl = aΔF,
ΔR = bΔr = bΔlsinα,
ΔR / ΔF = absin α = constant,
Accordingly, when a pulling force is generated in the tube, a pressing force R that becomes a gripping force is generated by the force, and a gripping force increase ΔR is generated in proportion to the pulling force increment ΔF (equilibrium with ΔF). . It is assumed that the intended gripping force R1 applied by packing has already been applied.

  In the self-balancing type pull-out prevention device as described above, since it continues to be gripped until it breaks, it is coupled with the fact that bolts and nuts are not required, such as building structures where infrastructure space is densified. It is also suitable as a water / drain joint. As will be described later, the joint according to the present invention is divided into a plurality of parts positioned in the front and rear in the axial direction, that is, as shown in FIG. 1A, a main body having engaging portions at both ends, and a flange. Although it is typical to join a tube body with a joint consisting of parts, it is only one example. And although the main-body part of the example of the figure is comprised by the straight pipe, it is easy to change this to an elbow pipe etc., for example.

  Since the present invention is constructed and operates as described above, there is no need for bolts and nuts to connect pipe joints, and there is no need to rotate the bolts and nuts. In addition, the present invention does not have a bulge provided with a bolt hole, and it is not necessary to turn it many times using a tool such as a spanner or a wrench in order to tighten the joint. It is suitable as a packing tightening device in a water supply / drainage pipe joint of a building having a high-density infrastructure space. Moreover, since the tightening torque can be easily managed, it is possible to perform construction with high connection reliability that maintains a certain level without depending on a skilled person.

  Hereinafter, the present invention will be described in more detail with reference to the illustrated embodiments. FIG. 1 is an illustration of a packing tightening device 10 in a pipe joint according to the present invention applied to a water supply / drainage pipe of a building, and this device 10 has a tubular body 11 having a cylindrical outer surface and the above-mentioned water supply / drainage pipe. And a joint 12 having a substantially conical inner surface, and a packing 13 disposed in a space formed by the outer surface of the tubular body and the inner surface of the joint (see FIG. 2).

  The joint 12 is divided into a main body portion 14 and a flange portion 15 positioned in the front and rear of the axial direction, and an engagement portion 16 is provided on the outer surface of the main body portion 14 and is engaged with the inner surface of the flange portion 15. An engaging mating part 17 is provided as an engaging partner of the part 16. The engaging portion 16 has a cylindrical cam portion 18 inclined inward with respect to the axial direction of the tubular body in order to move the main body portion 14 in the axial direction of the tubular body 11 by engaging with the engaging counterpart portion 17. And provided at three locations on the outer surface of the main body portion 14 at equal intervals of 120 degrees in the circumferential direction (see FIGS. 3 and 4). In the illustrated example, the radially outwardly increasing portions 19 each having a circumferential length of less than 60 degrees are provided at intervals of 120 degrees, and the cylindrical cam portion 18 is provided on the inside thereof. Note that a space of about 60 degrees between the three rising portions 19 becomes a passage portion of the engagement counterpart portion 17.

  The flange portion 15 has a cap nut-like structure in which a mating portion 20 is provided outside the inner surface as the mating mating portion 17. The mating portion 20 engages with the cylindrical cam portion 18, and has three radially inwardly rising portions 21 provided in the circumferential direction at equal intervals of 120 degrees on the inner surface of the flange portion 15. In the same manner as in the axial direction of the pipe body, it is provided to be inclined with respect to the flange portion 15 (see FIGS. 3 and 4). Further, a space of about 60 degrees between the three rising portions 21 becomes a passage portion of the rising portion 19 of the mating counterpart portion 16.

  The cylindrical cam portion 18 provided on the outer surface of the main body portion 14 is provided with an end of engagement (final position) with the mating portion 20 provided on the inner surface of the flange portion 15 in order to determine the end position (final position) of FIGS. As shown in FIG. The illustrated stop portion 22 is provided in a protruding shape that stops the mating portion 20 from returning along the inclined cylindrical cam portion 18. Engagement proceeds without contact, and the main body 14 of the joint moves in the axial direction to be engaged.

  The engaging part 16 and the engaging counterpart part 17 are configured as a cylindrical cam as a coupling means including a function of converting the rotational movement of the flange part 15 in the circumferential direction into the linear movement of the tubular body 11 in the axial direction. By determining the amount of linear motion in the axial direction, the degree to which the packing 13 is tightened is adjusted, and constant management of the tightening torque is performed. The flange portion 15 is provided with an anti-slip 23 on the outer surface that serves as a clue when rotating the flange portion 15.

  A rigid sphere 27 is rotatably disposed in the packing 13 disposed in the space 25 formed by the outer surface 24 of the cylindrical tube body and the conical inner surface 26 of the flange portion 15. The rigid sphere 27 is interposed between the outer surface 24 of the tube body and the inner surface 26 of the flange portion 15 when rotating the flange portion 15 in the circumferential direction with respect to the main body portion 14, and the main body portion in the axial direction of the tube body. The rolling bearing which moves 14 is comprised, and several are arrange | positioned substantially equally in the circumferential direction of packing. The rigid sphere 27 is formed of a rigid body having a hardness that can bite into the outer surface 24 of the tube body and the inner surface 26 of the flange portion 15.

  As the packing 13 itself, the aforementioned so-called rubber packing can be used. The illustrated packing 13 includes a front side portion 31 having a substantially wedge-shaped cross-section that enters the space 25 between the outer surface 24 of the tube body and the inner surface 26 of the flange portion 15, and an inclined inner surface of the tube body outer surface 24 and the main body portion 14. A rear side portion 32 having a substantially wedge-shaped cross-section that enters the substantially wedge-shaped space 25 between the rear side portion 28 and a locking portion 33 that is locked to the end portion of the tubular body 11 behind the rear side portion. Yes. That is, in the illustrated example, an inclined inner surface 28 is also provided at the rear as a conical joint inner surface that forms a substantially wedge-shaped space in which the packing 13 is disposed together with the cylindrical tube outer surface 24. Reference numeral 29 denotes a plurality of protrusions provided on the inner surface of the packing, which improves the adhesion to the outer surface of the tube body 11 and increases the water stoppage.

  As already described, the rigid sphere 27 is configured to be movable in the extraction direction while rotating around the axis in the circumferential direction of the tube when an external force in the direction of extracting the tube 11 and the joint 12 is applied. . That is, in order to cause the rigid sphere 27 to rotate by the external force in the pulling direction, the included angle 2α formed by the tube outer surface 24 and the inner surface 26 of the flange portion 15 in the space 25 is 17 ° ± 7 °, In addition, the outer diameter of the rigid sphere 27 is provided to be at least twice the minimum gap Δg between the tube outer surface 24 and the inner surface 26 of the flange portion 15 (see FIG. 7). In the illustrated example, the pipe body 11 is a carbon steel pipe (SGP) for piping, the surface of which is galvanized, the joint 12 is made of cast iron, and the rigid sphere 27 is made of steel. 10 to 10 are arranged.

  Next, the effect | action of the packing fastening apparatus 10 in the pipe joint which concerns on this invention is demonstrated. Each component shown in FIG. 1B is inserted into the connecting end portion of the tube body 11, and the engaging portion 16 provided in the main body portion of the joint 12 and the engaging portion provided in the flange portion of the cap nut type The mating part 17 is inserted into the mating part 17 such that each of the raised parts 19 and 21 is located in a space between the raised parts, and the flange part 15 is rotated when the insertion depth exceeds J1 ( (See FIG. 4). At that time, since the engagement counterpart 17 of the flange portion 15 moves along the inclination of the engagement portion 16 of the main body, it can be easily moved to the back and engaged without using a special tool. Become.

  More specifically, first, the rising portion 19 of the engaging portion 16 and the rising portion 21 of the engaging counterpart portion 17 are inserted into each other so as to be positioned in a space between the respective rising portions, and the insertion depth Let d1 be (FIG. 5A). At this time, no force is applied to the packing 13 yet. By applying a force to the flange portion 15, the rigid sphere 27 rotates in the axial direction of the tube (FIG. 5B), and when the insertion depth is d 2 (FIG. 5C), the cylindrical cam portion 18 is the shallowest portion of the mating portion. Therefore, the flange portion 15 can be rotated in the circumferential direction (FIG. 5D). Therefore, when a circumferential rotational force is applied to the flange portion 15, the mating portion 20 and the cylindrical cam portion 18 slide easily with respect to each other as a rolling element that reduces the friction by rolling the rigid ball 27 (FIG. 6A). . When the mating portion 20 slides on the cylindrical cam portion 18, the rigid sphere 27 moves in the circumferential direction and simultaneously in the axial direction of the tube, and generates a force f that compresses the packing 13 (FIG. 6C). When the flange portion is further rotated, the cylindrical cam portion 18 gets over the stop portion 22 of the mating portion 20 and becomes locked, thereby preventing the reverse movement (FIG. 6B). Since the insertion depth d4 at this time is uniquely determined, overtightening and undervariation of the packing 13 can be solved.

Here, with reference to FIG. 3, FIG. 4, the case where the pipe body 11 is a 4-inch pipe is demonstrated about the experiment example regarding the engaging part 16 and the engagement other party part 17. FIG. The 4-inch pipe has an outer shape = 114 mm and a tolerance = ± 0.8 mm. Therefore, the diameter of the flange portion is D0 = 114.6 mm.
If the maximum thickness of the packing is 6 mm, D1 = D0 + 2 × 6 = 16.6, mm
If the thickness of the joint body is 4 mm, D2 = D1 + 2 × 4 = 13.4, mm
If the thickness t1 of the raised portion is 5 mm, D3 = D2 + 2 × 5 = 144.6, mm
Assuming that the number of engagements between the engagement part and the engagement partner part is 3, the split angle α = 60 degrees, so that the angle between one engagement part and the engagement partner part is 57 degrees with a view of the fit margin. And
If the fitting margin in the diameter direction is Δmm, the flange inner diameter = D5, the inner diameter of the raised portion of the mating portion = D4, the outer diameter of the raised portion of the main body portion = D3, and the base diameter of the raised portion of the main body portion = D2. ,
D5-Δ = D3 = 144.6 mm,
D4-Δ = D2 = 134.6 mm,
Further, if D5−D4 = 2 × t2, t1 = t2 = 5 mm, and the overlap between the engagement portion 16 and the engagement counterpart portion 17 is 75% or more, Δ ≦ (5 mm × 25%) × 2 = 2.5 mm.
If Δ is small, the fitting strength increases. However, Δ is set to 1.4 mm in consideration of casting tolerance.
That is, D5 = 146 mm,
D4 = 136 mm,
It becomes.

Next, an experimental example regarding the angle of the inclined portion and the like will be shown. The conditions for the inclination of the cylindrical cam portion 18 and the mating portion 20 are defined by the initial height J1, the final height H1, and the length of the bottom arc g2. In the preferred example where the diameter of the tube is 4 inches, the initial height J1 is suitably about 2 mm from the initial torque. The final height H1 is determined by the displacement Δd required to generate the force f that compresses the packing 13.
Δd = d4−d2 = (H1 + J2) −d2,
In the case of a 4-inch pipe joint, the required displacement to compress the packing 13 is:
Δd = 6 mm,
d2 = J1 × 2 + 1.5 mm = 5.5 mm,
J2≈J1 + 1.5 mm = 3.5 mm,
Therefore, H1 = 8 mm,
G2 = πD3 × 57 degrees / 360 degrees = 72 degrees,
That is, the flange portion 15 is rotated by about 60 degrees and moved 72 mm in the circumferential direction, and is inserted about H1−J1 = 6 mm in the axial direction inward of the joint main body portion 14. The inclination of the cylindrical cam portion 18 and the counterpart portion 20 (6 mm / 72 mm) is easy because it has a gradient of 1/10 or less and moves with the rolling of the rigid sphere 27. In addition, the numerical value of these experiment examples is an illustration to the last, and should not be used for the restrictive interpretation of this invention.

  The state of the pipe joint connected by the packing tightening device 10 according to the present invention is shown in FIG. 2. As seen in FIG. The device 10 including the rigid sphere 27 is firmly gripped over the length L 1, and the rear side portion 32 is in close contact with the inclined inner surface 28 and pressed against the outer surface 24 of the tube body. Thus, the mechanical relationship of the rigid sphere 27 in the connecting portion such as the tube 11 and the joint 12 in the state of FIG. 2 in which the packing 13 is set and the flange portion 15 pressurizes it completely and the connection is completed. 7 is the same as that shown in FIG. 7, and the contents of the analysis are as described above. That is, the rigid sphere 27 bites into the outer surface 24 of the tube and the inner surface 26 of the flange portion 15 so as to face the external force, prevent the tube 11 from slipping out, and continue to be gripped until it breaks.

  As described above, according to the present invention, since the tightening torque can be easily managed, it is possible to perform the construction while maintaining a certain level without depending on the skilled worker. Even in a case where a difference is expected, a certain high connection reliability can be maintained. It should be noted that there is a situation where it is necessary to remove the joint portion where the connection is completed, and as expected, in such a case, in the apparatus 10 according to the present invention, the main body portion 14 and the flange portion 15 are provided. Applying a force that compresses the packing 13 in the axial direction to the packing 13 that is sandwiched between them, thereby separating the contact between the engaging portion 16 and the mating counterpart portion 17, and further bypassing the stop portion 33 It can be disassembled by rotating it in the direction opposite to that at the time of fitting.

  The packing tightening device in the pipe joint according to the present invention can be used for water supply and drainage piping in houses, offices, factories, etc., but it does not require any processing such as thread cutting or welding on the pipe material. Since it has a rigid ball as a fulcrum and has flexibility (vibration resistance) due to a rubber packing margin, it can be used for various purposes in equipment piping such as chemical industrial equipment and semiconductor manufacturing equipment.

An example of the packing fastening apparatus in the pipe joint which concerns on this invention is shown, A is a perspective view which shows the assembled state, B is a perspective view which shows the disassembled state. Sectional drawing which shows the state which has completed the connection. The joint structure used for this invention apparatus is shown, A is the edge part front view of a main-body part, B is the edge part front view of a flange part. Similarly, the joint structure used for the device of the present invention is shown, wherein A is an end side view of the main body, and B is an end side view of the flange. The engaging part and the engaging state of the engaging partner part will be described. A is a plan view showing a state before entering the engagement, B is a sectional view corresponding to A, and C is for entering the engagement. The top view which shows the state which moved to the axial direction, D is sectional drawing corresponding to C. FIG. The engagement part and the engagement state of the engagement partner part are described. A is a plan view showing a state where the engagement part is engaged and the engagement part is over the stop part, and B is a stop of the engagement partner part. The front view which shows the state which got over the part and was locked, C is sectional drawing corresponding to B. FIG. Explanatory drawing for analyzing the mechanical mechanism of the apparatus which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Packing fastening apparatus in pipe joint 11 Pipe body 12 Joint 13 Packing 14 Main body part 15 Flange part 16 Engagement part 17 Engagement part 18 Cylindrical cam part 19 Elevation part 20 Opposition part 21 Elevation part 22 Stop part 23 Anti-slip part 24 Tube outer surface 25 Space 26 Joint inner surface 27 Hard sphere 28 Inclined inner surface 29 Projection 31 Front river portion 32 Rear side portion 33 Locking portion 34 Connection end

Claims (4)

An apparatus for arranging a packing in a space formed by an outer surface of a cylindrical tube and an inner surface of a conical joint, and moving the joint in the axial direction of the tube to tighten the packing,
The pipe joint is composed of a main body part and a flange part positioned in the longitudinal direction of the pipe body, and an engaging part is provided on the outer surface of the main body part, while an engaging mating part is provided on the inner surface of the flange part. The portion has at least two cylindrical cam portions on the outer surface of the main body portion that are inclined with respect to the axial direction of the tubular body so that the joint is moved in the axial direction of the tubular body by engagement with the engaging counterpart. The mating mating part has at least two mating parts that engage with the cylindrical cam part on the inner surface of the flange part,
When the flange portion is rotated in the circumferential direction relative to the main body portion with the engagement portion and the engagement counterpart portion engaged, the axial direction of the tube body is interposed between the outer surface of the tube body and the inner surface of the flange portion. A rolling bearing for moving the main body is configured to tighten the packing, and after tightening, a plurality of rotatable rigid balls that can bite into the outer surface of the tube and the inner surface of the flange portion are arranged around the packing. A packing tightening device for a pipe joint, characterized by being arranged substantially evenly in the direction. The cylindrical cam portion provided on the outer surface of the main body portion is provided with a stop portion for determining the end of engagement with the mating portion provided on the inner surface of the flange portion. The packing tightening device for a pipe joint according to claim 1, wherein the packing tightening device has a protruding shape that stops returning along the cylindrical cam portion. The packing tightening device for a pipe joint according to claim 1, wherein the flange portion has a cap nut-like structure having a mating portion on the inner surface, and has a non-slip on the outer surface as a clue when rotating the flange portion. When an external force in the direction of pulling out the joint is applied to the tube, the rigid sphere can rotate around the tube circumferential axis and move in the pulling direction. In the space, the included angle 2α formed by the outer surface of the tube body and the inner surface of the joint is 17 ° ± 7 °, and the outer shape of the rigid sphere is the minimum gap Δg between the outer surface of the main body portion and the inner surface of the flange portion. The packing tightening device for a pipe joint according to claim 1, wherein the packing tightening device is configured to be twice or more of the above.

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