JPS585585A - Pipe joint - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves inserting the end of a joint pipe with no threads into the socket of a joint body in a pipe box, interposing a ring-shaped rubber gasket, (Relating to improvements in pipe joints in which union nuts are screwed and tightened to It provides pipe fittings.

In addition to being simple and inexpensive, the pipe fitting with no threaded end has the following advantages:
It has a relatively small nominal diameter of 13 to 50 m, and has a protective function that absorbs vibration, elongation, distortion, etc. of the piping due to the elasticity of the joint.
In addition, it has been favorably used as a joining method for low-pressure piping whose normal pressure is about 5 Kf/cm'' at most.

However, even when the union nut is tightened to the maximum tightening limit during joint construction, the rubber packing of the conventional pipe fittings still has a weak holding power against the joint pipe, resulting in a lack of pull-out force at the joint, which causes damage to the inside of the pipe. For those who find it extremely difficult to reliably prevent fluid leakage. Examining the reason for this, when tightening the union nut, the inner circumferential surface of the ring-shaped rubber gasket exerts a certain pressure on the outer circumference of the jointed pipe. KTr1 does not act to increase the pressing force on the union nut, and the subsequent retightening only serves to expand the rubber seal outward of its diameter, and the back and outer peripheral surfaces of the rubber seal and the pressing surface of the union nut and The frictional resistance between the inner circumferential surface and the inner circumferential surface increases rapidly, resulting in a state where the union nut cannot be tightened, and as a result, the holding force of the rubber seal against the joint pipe is insufficient! ! This was because he could be stopped. Therefore, in order to solve the above-mentioned conventional problems, it is necessary to take measures to minimize the frictional resistance between the rubber seal and the union nut, and to increase the additional tightening allowance over a wide range until the tightening becomes a restraining state. It is now possible to secure a satisfactory pull-out force, and various attempts have been made to date.

For example, (1) a metal washer is interposed between the back surface of the rubber packing and the pressing surface of the union nut, and a lubricant is administered between the pressing surface and the washer;
The tapered end surface of the socket is deepened, and the cross-sectional shape of the rubber packing is wedge-shaped, so that most of the rubber packing is buried within the tapered end surface of the socket, and a thick washer is interposed behind the rubber packing to tighten it. Rubber tubes (those that completely prevent the outer bulge of the rubber tubes,
Washer body hard thick synthetic M! There is one that is made of oily material and has an inwardly tapered surface that contacts the back surface of the rubber gasket. In all of the examples shown here, in order to exert a holding force against the joint pipe, the inner diameter of the rubber gasket must be made smaller than the outer diameter of the joint pipe so that it can be forcefully fitted into the joint pipe. Therefore, it is difficult to fit the rubber gasket into the joint pipe during pipe joint work. As a friend, when fitting the rubber packing into the joint pipe, extra man-hours were required, such as taking out the rubber packing set in the first union nut and fitting it. By the way, the reason why the inner diameter of the rubber seal is also made smaller than the outer diameter of the joint pipe is H1%tL.If the inner diameter of the rubber seal is increased, the inner circumferential surface of the rubber seal will come into contact with the outer surface of the joint pipe when tightening the joint. After the outer circumferential surface comes into contact with the socket, the washer, or the inner circumferential surface of the union nut, the contact frictional resistance acting on the outer circumferential surface of the rubber seal increases, and the tightening of the union nut approaches a restrained state. This is because the inner circumferential surface of the rubber seal comes into contact with the outer surface of the joint pipe, making it difficult to act as a holding force for the joint pipe when the union nut is subsequently tightened. Also, generally speaking, in fc type products with a washer interposed, the washer is often fitted eccentrically to the joint pipe or socket.
When tightening the union nut, the outer periphery of the washer collides with the end face of the socket, and the rubber seal often does not tighten even if the amount is increased. In addition, an extra washer is required as a component, and this washer is included in a set with a rubber gasket to reduce the inner diameter of the joint pipe.When joining the pipes, the set must be disassembled. Since it is necessary to fit the washer into place, the work is time-consuming, and the disassembly member that holds the washer is often lost, which deteriorates work efficiency. In addition, in the case of (1) above, it is almost impossible to prevent the lubricant from adhering to the outside of the jointed pipe, and as a result, there is a risk of losing the pull-out force, and if the lubricant is mineral oil If the rubber packing is made of natural rubber or sBRg, it absorbs oil and swells, resulting in a decrease in strength. In addition, even if the rubber seal is made of nitrile rubber with excellent oil resistance, its hardness is relatively low.

KIDID color tends to deteriorate over time. It is also possible to form a film by applying a powder lubricant (for example, Teflon powder, NoB@ powder, Ummo powder, graphite powder, etc.).
However, the lubricity between the rubber seal and the powder lubricant is
It is much worse than fluid lubricants, so you won't get the desired effect.

The present invention aims to solve the above-mentioned problem, and involves interposing a serpentine film made of a thin, soft, self-lubricating synthetic resin material between the rubber packing and the union nut. By tightening the union nut, even if the union nut is strongly tightened, the increase in frictional resistance is suppressed, and the additional tightening margin is secured over a wide range.The contact surface of the rubber seal against the joint pipe is expanded, and the union nut is tightened. The tightening is intended to allow the rubber packing to act effectively as a holding ring against the joint pipe, thereby exerting sufficient pull-out resistance and sealing effect.

Hereinafter, the pipe connection + related to "misfire" will be explained based on the drawings showing one embodiment thereof.

The first lamp is an exploded perspective view of the main components used in the pipe joint according to the present invention. In the same figure, 1f1 has a ring-shaped patch, and 6 has a snake-like film%.
9 is a union nut for tightening. These packskins 1
The film 6 and the union nut 9 are set together as shown in FIG. 3, and inserted into the joint pipe 15 as shown in FIG.
The pipes are connected by screwing and tightening the pipes. The cross-sectional shape of the gasket 1ri is usually a trapezoid in which the side in contact with the joint pipe 16 is larger than the other sides, and the back [102, the outer peripheral surface 3
, a contact surface to be brought into contact with the taper end surface 19 of the socket portion 17 of the joint body 16 is machined into the inner circumferential surface 5 which is to be brought into contact with the outer surface of the 4% joint pipe 15. The inner diameter of the packing 1 used for carrying out the failure test 1 can be made larger than the outer diameter of the joint pipe 15. The reason for this is that by tightening the union oak (91), the inner diameter is significantly reduced, and the holding force and water-stopping effect for the joint pipe 15 can be sufficiently exerted.
This is because it can be easily inserted into. In Fig. 1, the packing LH1 has a trapezoidal cross-sectional shape, which is the most commonly used shape, but the cross-sectional shape is not limited to the shape shown in the figure, and can be circular or oval. It may be shaped like a wedge, it may be wedge-shaped, it may be a combination of parts of these shapes, or it may be of any other shape. There is no problem at all, however, the pressing surface 14' of the union nut 9
When the seal is formed into a tapered shape, it is preferable for tightening to use one in which the angle αi of the back surface 2 of the seal I is made to match the taper angle.

The film 6 is the most important structural member for the joint of the unexploded Fj-1, and when fitting the packing 1 into the union nut 9, the film 6 is the most important component for fitting the unexploded Fj-1 into the union nut 9. It is interposed between the surface 14 and the inner circumferential surface lO, and has the function of reducing frictional resistance when tightening the union nut 9 to the joint body 16. In order to achieve this function, the material is made of IftifM resin, which is soft and hard to tear, and also has self-lubricating properties.The shape is a snake-like thin piece, and it is joined at the center. The packing 1 has nine through holes 7 with an inner diameter approximately the same size as the outer diameter of the tube 15, and has a circumferential width from the inner circumferential edge to the outer circumferential edge of the through hole 7. The width of the back surface 2 and the width in the outer circumferential direction 3 The film 6 is fitted into the union nut 9 together with the packing l, and the union nut 9 is attached to the joint body 16. The union nut 9 and the joint body 16, which are screwed together and tightened to the socket part 17, move and deform in response to the suppressed deformation of the seal 1.In this sense, the thickness If it exceeds 0.2+++u, it will lack flexibility, and if it is less than 0.01, it may be easily damaged.

Further, the film 6 may be used in two or three layers, and even in that case, the total thickness is 00O1 to 0.
．． As long as it stays within 2mm, it's a factory worker. As for the material of the film 6, according to the experimental results, Teflon (DuPont, USA product name) was the most preferable in terms of overall evaluation of flexibility, strength, and lubricity. In order to facilitate fitting the film 6 into the union nut 9, it is advisable to provide a radial cut 8'Jk on the outer periphery of the film 6, which is large enough not to become a starting point for damage. It is also good to provide a layer of adhesive in an adhesive box between the protective film 6 and the back surface 2 of the packing l.

The union nut 9 has a short cylindrical shape with a predetermined length, and has a female thread on the inner peripheral surface near one end that is to be screwed into the male thread 18 carved in the outer peripheral direction of the socket 17 of the joint body 16. 11
is engraved, and the other end has a shoulder 12'ft shape whose peripheral edge is constricted centripetally with respect to the axis. A socket 13 having a slightly thick outer diameter is opened. A pressing surface 14 is formed on the inner surface of the shoulder portion 12 to press against the back surface 2 of the packing 1.

The pusher 14 preferably has a tapered surface with an inclination angle of 9C or less, and its taper [1i]Vi is smoothly finished41. Ki when not smooth
, there is a risk that the film 6 may be torn during emergency feeding. Alternatively, the tapered surface may be a gently curved surface. The outer circumferential surface of the union nut 9 may be shaped into a polygonal layer for convenience in the threading operation during tightening (or may be carved with uneven grooves in the axial direction. In order to improve the screw efficiency during tightening, to protect the film 6, and to further reduce frictional resistance, it is preferable to apply dry powder lubricant (Teflon resin fine particles) to the inner surface where the female thread 11 is carved. When joining pipes using the material packing 11 film 6 and union nut 9, first fit and set the film 6 and packing 1 into the union nut 9 as shown in Fig. 3. shall be kept. To set it in this way, it is sufficient to do as shown in FIG.

ν1'' has a length several times the length of the union nut 9, the outer diameter el is equal to the inner diameter t/c of the through hole 7 of the film 6, and the inner diameter of the packing l is machined at an appropriate position II. big〃·
A flange 21 smaller than the outer diameter of the 7'j guide rod 2 is attached.
0, prepare one end of the guide rod 20, and attach the packing 11r.
Insert the film from the portrait side 4, then insert the film 6'ta
However, when the guide rod 20 thus constructed is inserted from the threaded end side of the union nut 9 and pulled in the direction of the arrow, the film 6 wraps around the packing 1 and sinks into the inside of the union nut 9. Pull the film 6 and the seal 1 until they come into contact with the pusher 1filL4 of the union nut 9, then pull out the guide 20 in the opposite direction.

Then, the film 6 and the packing l will be connected to the union nut 9.
It remains fitted inside the union nut 9 and will not fall off from the union nut 9 unless it is intentionally removed.

Insert the packing l, film 6, and union nut set in this way into the end of the joint tube 150 from the insertion port 13. In this case, the inner diameter of the packing l is larger than the outer diameter of the joining pipe 15, and it is stably fitted inside the union nut 9, so the joining member can be easily moved to the set position 1. It can be prepared for insertion into the joint tube 15. The tube end of the joint tube 15 prepared in this way is inserted into the socket 17 of the joint body 16 as shown in FIG.

A male thread 18 is carved on the outer circumferential surface of the socket 17 of the joint body 16, and the female thread 1 of the union nut 9 is inserted into the male thread 18.
Screw 1 together. Note that the end surface 19 of the socket portion 17 has an inclination angle a.
It has a tapered surface that expands outward with s, and the packing l
When the joint tube 15 is pushed, the force acts as a holding force for the joint tube 15. Tilt angle AS light 6Cf
As the union nut 9 is further tightened, the packing 1 expands and deforms in the outward and outward directions due to the pressing force in step 7, and as shown in FIG. The film 6b fills the space formed by the end 19 of the lower part 17, the inner circumferential surface 10 of the union nut 9, and the pushing surface 14, and the film 6b tightly contacts the pushing surface 14 and inner circumferential surface 10 of the union nut 9. Then, the back surface 2 and the outer circumferential surface 3 of the packing L are directly connected to the inner circumferential surface 10 of the union nut 1.
Avoid contact with the push surface 14. Therefore, the frictional resistance when retightening the union nut 9 is determined by the coefficient of friction between the pressing surface 14 and inner peripheral surface lO of the union nut 9 and the film 6, and is extremely small compared to this coefficient of friction. , frictional resistance is +7) compared to the conventional one.17)
(KVi does not increase rapidly. Moreover, since the washer does not use this at all, it
Further tightening will not be prevented due to collision interference with fl19. For these reasons, by the time the union nut 9 is retightened, a sufficient retightening allowance can be secured, and the tightening t'ill is fully tightened to ensure the joint of the seal 1. It acts as a pressing force on the pipe 15, and it becomes possible to greatly increase the contact surface between the joint pipe 15 and the packing 1, and these have a synergistic effect.
Join! 15 can be increased, and therefore a large pull-out force can be obtained.

The above example describes the case where the joint pipe 15 is connected to the joint main body 16, but instead of the joint main body 16, a pipe having an outer diameter larger than the outer diameter of the joint pipe 15, and a limb pipe Pipe 15 to be joined to the pipe to be joined which has a male thread carved into the end of the pipe.
Of course, the present invention also applies to the case where the present invention is connected, and such a case does not depart from the gist of the present invention.

As described above, the pipe joint according to the invention is similar to the above, and since the film 6, which is flexible, hard to break, and highly self-lubricating, is interposed between the union nut 9 and the packing l, the following will be described. It has a number of technical effects.

■ Retightening of the union nut is smooth and easy, and it can be tightened with a small torque.Especially when just stopping water leakage, manual tightening alone can provide sufficient water stopping effect. ■ Since the frictional resistance when retightening the union nut is small, it is possible to widen the range of retightening until the tightening becomes restricted, and the difference in diameter of the bottom between the joint pipe and the socket can be reduced. Even in some cases, very high tube holding forces are obtained.

(2) Similar to the case (2) above, even if the inner diameter of the ring seal is larger than the outer diameter of the joint tube, an extremely high tube holding force can be obtained.

■ As the retightening allowance becomes wider, it becomes possible to increase the thickness of the packing in the axial direction compared to conventional ones, which increases the contact area between the joint pipe surface and the inner peripheral surface of the packing. , the holding force of the tube can be further increased.

■ Since there is no need to insert a washer between the pressing bend of the union nut and the rear side of the packing, it is possible to form the pressing surface of the union nut into a tapered shape. When a pulling force is applied to the pipe, that force is converted into an adhesion force of the packing to the surface of the jointed pipe, and acts to independently resist the pulling force.

■ If you fit the packing and film, which are the joining members, into the union nut before joining the pipes, they will not fall off and dissipate after that, so there is no risk of losing all the parts. do not have.

■ The packing and film fit together in the union nut in an extremely stable manner, so combined with the fact that the inner diameter of the fitted packing is larger than the outer diameter of the joint pipe, it is possible to avoid disassembling the joining member. It is possible to insert the tube into the pipe to be joined while the housing is set and move it freely, thereby reducing the number of man-hours required for pipe joining work.

(2) Since an extremely thin film is sufficient, even if the material is expensive like Teflon, the manufacturing cost is relatively low, and an economical pipe joint can be obtained.

■ The pipe joint according to the present invention can be used with other metal pipes including steel pipes, pipes with H, ITM resin linings, hard vinyl chloride pipes, polyethylene pipes, etc. Not only can it be used to join synthetic resin pipes, but it can also be used to join pure lead pipes and alloy lead pipes. It can also be used to join #s together, and its range of use is extremely wide.

Among the above-mentioned effects, particularly regarding the holding force of the joint tube, examples thereof will be described and it will be made clear that the effects are excellent.

This example shows a pipe fitting related to J that failed to explode and a conventional pipe fitting (
(with an iron washer interposed between the back of the packing and the pushing surface of the union nut), install the piping as shown in Figure 7, apply water pressure inside the piping, and set the limit pressure under F5r constant conditions. This is a comparative test of the expansion and contraction ji of the pipe joint. During the test, in order to ensure the same conditions between the unexploded J model and the conventional model, the packing, union nut, joint body, and joint pipe were the same for both comparisons, and the following points were especially taken into consideration: We took note of this.

l) The packing material is BR, and is molded from a material with the same hardness, and prior to use, it is cleaned to remove oil and fat. The inner diameter of the packing and the outer diameter of the joining pipe were also large.

2) The union nut has a thread efficiency of -4,
A dry lubricant of Teflon powder was applied to the threaded part.

3) Add hard vinyl chloride lined steel pipe for water supply to the joint pipe (
, TWIFA K116-1972) and hard vinyl chloride t (VP) for tap water, and prior to implementation, the inner and outer surfaces were washed to remove oil and fat.

4) When tightening the union nut, to ensure the same tightening torque, a torque meter was attached to the vibration wrench and the actual torque was calculated.

5) When measuring with a pressure gauge, when water pressure is applied to the pipe and the water pressure is released, expansion and contraction will occur at the pipe joint, so keep the specified water pressure applied for 4 minutes, and the expansion and contraction during that time will be 0. 2
This is done when the score is W or higher.

6) The expansion and contraction I was measured when water pressure f was applied and held for 4 minutes and when the water pressure was released, and the difference was taken as the expansion and contraction value.

The results are shown in Table 1 of the comparative test.

In the same table, test numbers A NG and Kibori J are shown, and a to g are conventional tests. Connection 4: outer diameter D1 of r, inner diameter D2 of rubber seal, length L1, back angle α1, insertion diameter D3 of union nut. The inner 11rJ radius 4, push bending angle α2, inner diameter D5 of the joint body, and cut face angle α1 are indicated with the same symbols in FIG. 6, respectively.

(Continued on page 21) As can be seen from the results in Table 1, the joints A-Gi of the present invention using Teflon film and the conventional joints Bxg for comparison also have clearly high pipe retention. It is recognized that they have power. The test code D1d uses a hard vinyl chloride pipe as the joint pipe, but the test code of the present invention is about 2 mm smaller in the outer diameter of the joint pipe than the test code C pipe. It is observed that the retention force is distorted. Test symbol IJ e and F,
Item f was tested under almost the same conditions except for the length of the seal, but as the length of the seal increases (therefore, the inner surface of the seal and the outer surface of the joint When the contact area with the tube increases), it is recognized that the holding force of the tube increases further in the case of the present invention, whereas the holding force of the tube tends to decrease in the conventional case. Test record MG, g'7) was used in which the angle αJ*''! between the pushing surface of the union nut and the back surface of the packing was set to 20 degrees, but for the test code G, the other conditions were t' It is recognized that t has a higher retaining force for the pedestal with rollers compared to the test number E, which was made equal.However, the test number g (?) This is because the back bending angle α of the seal is small, making it impossible to use iron washers, and the seal is tightened with a union oak, which has very poor pressure resistance. There is a certain difference.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view showing the main components of a pipe joint related to unexploded FIAK, Fig. 2 is a perspective view showing how the parts shown in Fig. 1 are set together, and Fig. 3 is a perspective view showing the parts shown in Fig. 1. Figure 4 is a partial cross-sectional view of the pipe joint according to the present invention showing the state in which the joint has started, Figure 5 is a partial cross-sectional view showing the completed joint state, Figure 6 t'ff Packing and film FIG. 7 is a sectional view showing a state in which the pipe joint is not fitted into a union nut but is inserted separately into a joint pipe to start joining, and FIG. 7 is a diagram showing a water pressure test state of the pipe joint. l...Packing 6...Film 9...Union oak) 15...Joint pipe 16...Joint body
31... Water pressure test pump 32... Pressure gauge 33.
... Air venting wire patent applicant Kawanishi Suido Kiki Seisakusho Co., Ltd. Agent Patent attorney Toshihiko Uchida

Claims (1)

[Claims] 1. Insert an unthreaded joint pipe into a pipe or fitting body with a male thread carved on the outer circumferential surface and a socket 8TK, insert and insert a ring-shaped rubber packing, and screw and tighten the union nut into the socket. In the structure of the pipe joint, a thin, soft, strong, self-lubricating resin film to be adhered to the back surface of the rubber packing or the back surface and outer peripheral surface of the union nut is used. A pipe fitting characterized by an internal fitting.