JPH0240175B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The disclosed technology belongs to the field of the structure of a hydraulic sealing device for a pipe end used for hydraulic test testing and hydraulic expansion of various pipes.

<Explanation of the gist> The invention of this application is a pipe end hydraulic sealing device used for pipe pressure tests and hydraulic expansion, in which the main body of the sealing device is closely pressed against the entire circumference of the end of the pipe to be set. This invention relates to a pipe end hydraulic sealing device which is provided with a pressure fluid supply/discharge cavity for supplying pressure fluid to the inside of the pipe and is tightened between frames via tie rods, and in particular, the invention relates to a pipe end hydraulic seal device which is configured to be tightened between frames via a tie rod. The proximal end of the spool is fixed to the spool, and a sleeve having a pressurized fluid supply and drainage cavity with a ring-shaped stepped portion is slidably inserted over the spool, and a tube end seal portion is formed at the tip of the sleeve. The spool is connected to a seal fitting that is in close contact with the end of the pipe, and a pressure fluid supply/exhaust cavity for pumping pressure fluid into the pipe is provided inside the spool at the end, and the pipe communicates from the sleeve to the seal portion. This invention relates to an end hydraulic seal device.

<Prior art> As is well known, piping is widely used in many industrial fields, and depending on its use, pressure resistance and corrosion resistance are required. Corrosion-proofing treatment is being carried out through hydraulic pipe expansion.

In this type of work on the tube body, considerable hydraulic pressure acts inside the tube, and therefore a tube end hydraulic sealing device is required.

The general form of the conventionally used pipe end hydraulic sealing device is as shown in FIG.
The frames 4 are brought into contact with each other, the frames 4, 4 on both walls are clamped together via the tie rods 5, 5, and sealed, the water inlet 6 of one frame 4 is closed, and the water inlet 6 of the other frame 4 is closed. A predetermined high-pressure water is fed under pressure into the pipe 1 to perform a predetermined work.

<Problems to be Solved by the Invention> However, in the above-mentioned conventional pipe end hydraulic sealing device, as the pressure of the pressure water supplied into the pipe 1 increases, the cross-sectional area of the pipe 1 decreases. The pressure P x S, which is the pressure P applied to S, is applied to the frame 4 as an axial force, and as a result, the tie rod 5 stretches, which reduces the sealing function of the seal 3. However, there was a problem that leaks occurred, and the specified pressure resistance test and tube expansion could not be achieved.

To deal with this, it is possible to make the preload on the packing 3 sufficiently large and the tension on the tie rod 5 sufficiently large, but if you do this,
When the wall thickness of the tube 1 is thin or when the length of the tube 1 is large, there are problems such as buckling deformation of the tube due to an excessive compressive load applied to the tube 1.

Further, there was also a disadvantage that the designed thickness of the tube 1 to be used for the final purpose did not match the thickness of the tube 1 during testing, etc., resulting in increased costs.

<Object of the Invention> The object of the invention of this application is to solve the problem of the sealing of the pipe end hydraulic sealing device based on the above-mentioned prior art as a technical problem, while keeping the thickness of the pipe to the thickness of the pipe for the final use. It is an object of the present invention to provide an excellent pipe end hydraulic sealing device that can apply a predetermined hydraulic pressure, seal reliably, and prevent buckling deformation, etc., and is useful in piping technology applications in various industries. It is something.

<Means and actions for solving the problem> In order to solve the above-mentioned problem, the invention of this application, which is based on the scope of the above-mentioned claims, is based on a spool of a frame fixed by a tie rod. The pipe end of the pipe is set in contact with the pipe end seal portion of the movable sleeve that has been inserted, and a predetermined pressure fluid is supplied from the spool through the pressure fluid supply and drainage cavity of the spool. Pressure fluid is applied from the sleeve into the pipe to perform a predetermined work, and during this time, as the applied fluid pressure increases, the axial force due to the pressure inside the pipe also increases, but the pressure of the sleeve of the sealing device body outside the spool increases. Since the hydraulic pressure applied to the ring-shaped stepped portion is equal to or greater than the axial force, the seal at the pipe end is reliably maintained and no leakage occurs, and furthermore, the above-mentioned frame A technical measure is taken in which the rod of the hydraulic cylinder fixedly attached to the sleeve is fixed to the bracket of the sleeve, thereby making the sealing of the sealing part more reliable.

<Example> Next, an example of the invention of this application will be described below based on FIGS. 2 and 3. Furthermore, the first
Components having the same features as those in the drawings will be described using the same reference numerals.

In the embodiment shown in FIG. 2, reference numeral 7 denotes a pipe end hydraulic sealing device which constitutes the gist of the invention of this application, and is used to seal the pipe end 2 of the pipe 1. In the figure, for convenience of illustration, only one end is shown. is shown, but in reality, it is also provided at the other end (not shown), and the frames 4' are connected by tie rods 5, 5, . . . .

A spool 9 is fixed to the inside of the frame 4' via bolts 8, 8, . A pressurized fluid supply and drainage cavity 10 is formed through '.

Reference numeral 11 denotes a sleeve, in which a pressure fluid supply/discharge cavity 10' having a ring-shaped stepped portion 12 having the following preset depth is formed, and the base side of the large diameter pressure fluid supply/discharge cavity 10' is is slidably and fluid-tightly fitted onto the spool 9 via the seal 3''.

On the other hand, the front end side of the sleeve 11 has a flange portion 1
3 into a tapered portion 14 to form a watertight abutting seal portion all around the flare 15 formed at the tube end 2 of the tube 1.

A seal 16 is divided into two parts in the circumferential direction, contacts the flare 15 of the pipe 1 from the outside, is removably fastened to the flange 13 via bolts 8, and connects the flare 15 to the tapered part of the seal. 14 and is pressed and tightened.

In the above configuration, the tube end 2 of the tube 1 is formed into a tapered flare 15 that matches the tapered portion 14 of the sealing portion of the sleeve 11 by appropriate means,
This is brought into contact with the tapered part 14 of the sleeve 11 that slides in a watertight manner on the spool 9 in the drained state, and the seal jaw 16 is brought into contact with it from the outside.
By fastening to the flange portion 13 with bolts 8, the tube end 2 of the tube 1 is fastened to the tapered portion 14 as a seal portion of the sleeve 11 in a watertight state all around.

Then, by pressing the start switch (not shown), the high pressure water pump is activated via the switching valve (also not shown), and the spool 9 is operated from the water inlet 6'.
High-pressure water is fed into the supply and drainage cavity 10 of.

Then, the fed high pressure enters the supply/discharge cavity 10' of the sleeve 11 from the supply/discharge cavity 10 of the spool 9,
Through this, it is fed into the inside of the pipe 1 and subjected to a predetermined hydraulic test or hydraulic pipe expansion.

Then, as the pressurized water pressure gradually increases, the cross-sectional area of the pipe 1 is S, and the supply/discharge control 1 of the sleeve 11
Assuming that the cross-sectional area of 0' is A, an axial force of P×(SA) acts on the sleeve 11 as a reaction force to the applied pressure P.

However, in the invention of this application, by designing the annular cross-sectional area of the ring-shaped stepped portion 12 of the sleeve 11 to be equal to the cross-sectional area of (S-A) above, the pressure fluid supply and drainage of the sleeve 11 is improved. cavity 10'
The pushing force in the direction of the tube 1 at is substantially equal to the axial force and can be applied in the opposite direction, so that the sleeve 11 does not move laterally with respect to pressure.

Therefore, there is no risk of leakage occurring due to the tapered portion 14 of the sealing portion of the sleeve 1 not being tightly sealed to the flare 15 of the tube 1.

On the other hand, as the water pressure inside the pipe 1 increases, the diameter of the pipe 1 expands and becomes larger, and the axial length contracts accordingly, so that the sealing jaw 16 is reliably clamped to the sleeve 11 via the bolt 8. As a result, the sleeve 11 slides inward and is drawn toward the tube 1, and from this point on, the seal against the flare 15 is not weakened and no leakage occurs.

Therefore, the water pressure test and the water pressure expansion of the pipe 1 are reliably performed.

In addition, this spool 9, the supply and drainage cavity 1 of the sleeve 11
0 and 10' are reliably prevented by the gaskets 3' and 3''.

When the specified work is completed, the water can be drained from the water inlet 6' by switching the switching valve, or the water can be removed from the water pressure by removing the bolt 8 and sealing the seal 16.
and remove the tube 1 from the sleeve 11.

In this embodiment, by making the annular cross-sectional area of the stepped portion 12 larger than the above-mentioned cross-sectional area (S-A) by a designed amount, the sleeve 1 is always maintained during operation.
It is also possible to positively ensure the seal by pressing the tube 1 in the direction of the tube 1 by a set pressure.

Further, in this case, it is necessary to design the tube 1 to such an extent that buckling deformation does not occur.

As a design change, a hydraulic cylinder may be used instead of the seal bolt 8.

Various design changes are also possible, such as attaching the tube end hydraulic sealing device to one end of the tube and using only a pressure sealing device at the other end.

In the embodiment shown in FIG. 3, the pipe end 2 of the pipe 1 is brought into contact with the sleeve 11' through the seal gasket 3, and the hydraulic cylinder 18, A predetermined number of rods 18 are provided, and the tip of a rod 20 extending forward and fixed to the piston 19 is fixed to a flange-shaped bracket 21 fixed to the sleeve 11'. is switching valve 2
3. This is an embodiment in which it is connected to a bolt 25 via a hydraulic pump 24.

In this embodiment, pressurized water from the water inlet 6' of the spool 9 is supplied and discharged from the supply/discharge cavity 10 to the end of the pipe 1 which is in contact with the end of the sleeve 11' via the packing 3, as in the above-mentioned embodiment. The sleeve 11' is introduced into the pipe 1 through the cavity 10', and the same operations as described above are performed, except that the sleeve 11' is set in the pipe 1 by the action of the respective hydraulic cylinders 18, 18 provided on the frame 4'.
In addition to resetting, the sleeve 1 is automatically adjusted in response to fluctuations in the water pressure on the pipe 1.
1' can be moved slightly forward and backward.

In this embodiment, it is also possible to modify the design so that the pressure of the hydraulic cylinder is appropriately adjusted via an automatic adjustment device while detecting the water pressure in the supply/exhaust cavity 10' within the sleeve 11'.

<Other Embodiments> It goes without saying that the embodiments of the invention of this application are not limited to the above-mentioned embodiments. Adoptable.

<Effects of the Invention> As described above, according to the invention of this application, basically, in a pipe end hydraulic sealing device used for hydraulic pressure testing or hydraulic expansion of a pipe, high pressure liquid is fed into the pipe, and as a result, the pipe Even if the tube expands in the radial direction and contracts in the axial direction, the sealing part is always tightly pressed to ensure a complete seal, so that the applied pressure fluid will never leak, and the tube will remain in the radial direction. , an excellent effect is achieved in that the hydraulic pressure does not change even if axial deformation occurs.

Therefore, an excellent effect is achieved in that the precision and control of the manufactured tubes can be performed well.

The seal at the end of the tube is formed at the tip of the sleeve, which can be slid freely by inserting it into the spool fixed to the frame, so that the movable sleeve always smoothly follows the expansion and contraction behavior of the tube. However, the excellent effect of stably maintaining the seal against the end of the tube is achieved.

In particular, since the seal portion of the sleeve is connected to the sealing joint for the tube end, a reliable seal can be maintained even when the tube expands and contracts.

Furthermore, since the seal portion is formed on the sleeve, there is an effect that it is easy to seal a pipe having a large diameter.

In addition, because a pressurized fluid supply and drainage cavity is formed inside the sleeve that communicates with the supply and drainage cavity in the spool and the seal part at the end of the tube, even though the sleeve slides as the tube expands and contracts, , the excellent effect of stably applying pressure liquid is achieved.

Furthermore, since the rod of the hydraulic cylinder provided on the frame is connected to the bracket of the sleeve, not only can the setting and resetting of the pipe be performed smoothly and reliably by the hydraulic cylinder, but also the pipe can be easily set and reset. An excellent effect is also achieved in that the pressure can be adjusted by the hydraulic cylinder when fluctuations occur in the sleeve during the process of supplying pressurized fluid following the movement of the sleeve.

In the sleeve, by having a stepped portion, the ring-shaped cross-sectional area of the stepped portion is equal to the cross-sectional area of the difference between the cross-sectional areas of the tube and the sleeve.
By increasing the setting amount, the sleeve will follow the axial deformation of the pipe during pressurization, but
Since a large axial force is not applied to the sleeve, or rather no pressure is applied at all, or even a slight pressure can be applied, an excellent effect is achieved in that the seal is maintained more reliably.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view of a pipe end hydraulic sealing device based on the prior art, FIGS. 2 and 3 are explanatory views of an embodiment of the invention of this application, and FIG. 2 is a longitudinal sectional view of one embodiment. FIG. 3 is a longitudinal sectional view of another embodiment. 2...Pipe end, 10, 10'...Pressure fluid supply and drainage cavity, 7,
7'...Sealing device main body, 5...Tie rod, 4,
4'... Frame, 9... Spool, 11, 11'... Sleeve, 14... Seal portion, 12... Step portion, 17...
Pressure fluid supply and drainage cavity, 20...rod, 21...bracket.

Claims (1)

[Scope of Claims] 1. In a pipe end hydraulic sealing device in which a sealing device main body which is pressed against the entire circumference of the pipe end and has a pressure fluid supply and drainage cavity is provided on a frame fixed to a tie rod, a spool is attached to the frame. is fixedly installed in the spool, and a seal part connecting a sealing tube for the pipe end is provided at the tip of a sleeve as a sealing device main body that is externally inserted into the spool through the pressure fluid supply and drainage cavity. A ring-shaped stepped portion is provided inside the pressure fluid supply and drainage cavity of the sleeve that communicates with each other, and a pressure fluid supply and drainage cavity that communicates with the sleeve and the seal portion is formed within the spool. Pipe end hydraulic sealing device. 2. A pipe end hydraulic sealing device in which the sealing device main body, which is pressed against the entire circumference of the pipe end and has a pressure fluid supply/exhaust cavity, is provided on a frame fixed to a tie rod, and a spool is fixed to the frame, and A tube end seal part is provided at the tip of a sleeve as a sealing device main body that is inserted externally into the spool, and a ring-shaped stepped part is provided inside the sleeve. A pipe end hydraulic sealing device, characterized in that a pressure fluid supply and drainage cavity communicating with the pipe is formed, and a rod of a hydraulic cylinder provided on the frame is connected to a bracket provided on the sleeve.