Hydraulic Testing Equipment for Pipe Joints

Abstract

To provide a pipe joint water-pressure test device that prevents wear of an elastic ring to secure water tightness.SOLUTION: A pipe joint water-pressure test device has: a main part 5; a first water cut-off unit 6 that is provided in an outer face on one end side in a pipe axis direction of the main part 5, and is tightly contactable with an inner face of a pipe 2 of jointed one, over a whole circumference in a circumferential direction; a second water cut-off unit 7 that is provided in an outer face on the other end side in the pipe axis direction of the main part 5, and is tightly contactable with an inner face of a pipe 3 of jointed other, over a whole circumference in the circumferential direction; and an extrusion device 8 that generates extrusion force along the pipe axis direction. Both water cut-off units 6 and 7 are configured to have: a fixing flange 11 that is fixed to the outer face of the main part 5; an oscillation flange 12 that can oscillate in the pipe axis direction by the extrusion force of the extrusion device 8, and is provided with a space separated from the fixing flange 11 in the pipe axis direction; and an elastic ring 13 that is provided so as to be across the fixing flange 11 and the oscillation flange 12, and deforms outward accompanied by approach of the fixing flange 11 and the oscillation flange 12 in the pipe axis direction to abut with the inner faces of the pipes 2 and 3.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a hydraulic testing device for pipe joints. [Background technology]

[0002] In pipelines for water supply, sewerage, industrial water, etc. constructed with ductile iron pipes, etc., after the joining work of the joints is completed, a test is carried out in which water pressure is applied to the joints (for example, pressurized to 0.5 MPa) in order to check the soundness (watertightness) of the watertight part of the joints. In the case of large-diameter pipes with a nominal diameter of 900 or more (there are also cases where the nominal diameter is 800 or 700), for example, a water pressure test device according to the following Patent Document 1 can be used.

[0003] In a test using this hydraulic testing device, first, a sealant 5 (rubber ring) with a U-shaped circumferential cross section is placed on the inner surface of the pipe joint 1, and a waterstop 8 is applied to the inner surface. Next, the waterstop 8 is pressed outward by reaction plates 20, 21 which are advanced outward in the pipe diameter direction by operating a set screw 22, and this pressing force causes the tongue-shaped portion 7 of the sealant 5 to adhere closely to the inner surfaces of the socket 2 and the insertion port 3, forming an annular sealed space 33 in the pipe joint 1 for filling with water under pressure (see Figs. 1 and 7(b) of Patent Document 1, etc.).

[0004] The test according to Patent Document 1 requires an operator to enter the pipe to operate the set screw 22, and is therefore difficult to apply to small-diameter pipes where an operator cannot enter. For this reason, a test method in which water is directly filled into the pipe is often used for small-diameter pipes. However, even small-diameter pipes require a large amount of water depending on the length of the pipe in the construction section, although not as much as large-diameter pipes, which is problematic in terms of cost.

[0005] As a test device that may be applicable to small-diameter pipes, for example, a watertightness inspection device according to the following Patent Document 2 has been proposed. This watertightness inspection device has a first seal device 10 disposed opposite the inner peripheral surface 4 of one of the joined pipes 1 and 5, and a second seal member 20 disposed opposite the inner peripheral surface 7 of the other pipe 5. The seal devices 10 and 20 have wheels 11, 12, 21, and 22 inserted into a support shaft 31, and ring-shaped seal bodies 15 and 25 are provided between the wheels 11, 12, 21, and 22. When the wheels 11, 12, 21, and 22 move relatively close to each other, the seal bodies 15 and 25 (elastic rings) expand in diameter and are pressed against the inner peripheral surfaces 4 and 7.

[0006] The wheels 11, 12, 21, 22 of both sealing devices 10, 20 are configured to move toward each other by an actuator 40. This actuator is composed of a hydraulic jack 41 disposed between one of the sealing devices 10 and the base plate 30, and a transmission body 42 disposed between both sealing devices 10, 20. A pin 32 is provided at the free end of the support shaft 31 to restrict the movement limit of the wheel 22.

[0007] When the hydraulic jack 41 is extended, the first sealing device 10 moves toward the second sealing device 20 while being guided by the support shaft 31, and first, the ring 12 of the first sealing device 10 abuts against the rubber packing 43 provided on the transmission body 42, and the transmission body 42 moves integrally. Next, the rubber packing 44 on the opposite side of the transmission body 42 abuts against the ring 21 of the second sealing device 20. When the hydraulic jack 41 is further extended in this state, the pair of rings 11, 12, 21, 22 of both sealing devices 10, 20 move relatively closer to each other, and the seal bodies 15, 25 move outward while being expanded in diameter, and the outer circumferential surfaces 18, 28 of the seal bodies 15, 25 are pressed against the inner circumferential surfaces 4, 7 of the pipes 1, 5 (see paragraphs 0011-0022, Figs. 1, 2, etc. of Patent Document 2). [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Utility Model Application Publication No. 63-240 [Patent Document 2] Japanese Patent Application Publication No. 8-62089 Summary of the Invention [Problem to be solved by the invention]

[0009] In the configuration according to Patent Document 2, the first sealing device 10 is freely guided in the axial direction by the support shaft 31, so that when the speed of the extension movement of the hydraulic jack 41 is high or when the friction between the first sealing device 10 and the support shaft 31 is high, the sealing body 15 may be tightly pinched between the two wheels 11, 12 and expand in diameter during the axial movement of the first sealing device 10. Then, the expanded sealing body 15 slides against the inner peripheral surface 4 of the pipe 1, and the sealing body 15 on the first sealing device 10 side may be worn compared to the sealing body 25 on the second sealing device 20 side, which may cause a loss of watertightness.

[0010] Furthermore, even if the sealing body 15 of the first sealing device 10 and the sealing body 25 of the second sealing device 20 were to expand in diameter evenly, after each sealing body 15, 25 comes into contact with the inner surface of the pipes 1, 5, the sealing body 15, 25 must be further pressed against that inner surface to obtain water-stopping surface pressure, and therefore the sealing body 15 of the first sealing device 10, which has a longer sliding distance after contact, tends to be more susceptible to wear than the sealing body 25 of the second sealing device 20.

[0011] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to prevent wear of the elastic ring and ensure watertightness. [Means for solving the problem]

[0012] In order to solve the above problems, the present invention provides: A main body portion extending along a tube axis direction; A first water stop unit is provided on an outer surface of one end of the main body in the pipe axis direction and is capable of tightly contacting an inner surface of one of the connected pipes over an entire circumference in the circumferential direction; A second water stop unit is provided on an outer surface of the other end of the main body in the pipe axis direction and is capable of tightly contacting an inner surface of the other connected pipe over an entire circumference in the circumferential direction; An extrusion device that generates an extrusion force along the tube axial direction; The water pressure testing device for a pipe fitting has a first water-stopping unit and a second water-stopping unit, the first water-stopping unit being configured to have a fixed flange fixed to the outer surface of the main body, a sliding flange arranged at a distance from the fixed flange in the pipe axis direction and capable of sliding in the pipe axis direction along the outer surface of the main body by the pushing force of the extrusion device, and an elastic ring arranged to straddle the fixed flange and the sliding flange and deforms outward as the fixed flange and the sliding flange approach each other in the pipe axis direction to abut against the inner surface of the pipe.

[0013] In this way, by making one of the pair of flanges of each watertight unit a fixed flange, the elastic ring that spans between the fixed flange and the sliding flange hardly moves in the axial direction of the pipe even when the sliding flange is moved by the extrusion device. Therefore, wear caused by sliding between the elastic ring and the inner surface of the pipe does not occur, and watertightness can be ensured.

[0014] In the above configuration, the extrusion device may be provided between the first water stop unit and the second water stop unit. In this way, by providing the extrusion device between the two water stop units and sharing the driving force of the sliding flanges of the two water stop units with the extrusion device provided between the two water stop units, the pressing forces acting on the inner surface of the pipe from the elastic rings of the two water stop units can be equalized, thereby ensuring higher watertightness.

[0015] In each of the above configurations, the extrusion device may be a cylinder having an inner cylinder integral with the main body, an outer cylinder coaxially provided outside the inner cylinder, and an annular piston provided between the inner cylinder and the outer cylinder. In this way, the pressure-receiving area of ​​the piston of the cylinder can be increased, so that even if the pressure of the working medium supplied to the cylinder is small, a large force toward the fixed flange can be applied to the sliding flange.

[0016] In each of the above configurations, a biasing member may be provided between the fixed flange and the sliding flange to bias the two flanges in a direction separating them. In this way, the fixed flange and the sliding flange can be quickly separated from each other by the biasing force of the biasing member after the hydrostatic test, and the elastic ring can be reduced inward in diameter. Therefore, when the hydrostatic test device is moved to the next test position (joint), the elastic ring does not slide against the inner surface of the pipe, allowing the hydrostatic test device to be moved smoothly and preventing wear due to the sliding of the elastic ring.

[0017] In each of the above configurations, the elastic ring may have a protruding portion that protrudes toward the inner wall of the pipe beyond a sandwiching region where the fixed flange and the sliding flange are sandwiched in the pipe axial direction, and a recess formed in the sandwiching region and on the pipe axial center side of the protruding portion. In this way, when the fixed flange and the sliding flange approach each other in the pipe axial direction, the elastic ring is likely to protrude toward the inner wall of the pipe, so that a tight contact state between the elastic ring and the inner wall of the pipe can be smoothly ensured. Effect of the Invention

[0018] In this invention, by making one of the pair of flanges of each water stop unit a fixed flange, even if the sliding flange is moved by the extrusion device, the elastic ring that straddles the fixed flange and the sliding flange hardly moves in the pipe axial direction. Therefore, wear caused by sliding between the elastic ring and the inner surface of the pipe does not occur, and watertightness can be ensured. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a cross-sectional view showing a first embodiment of a water pressure test device for a pipe joint according to the present invention (in a state before a water pressure test); [Diagram 2] FIG. 2 is a diagram showing the positional relationship between the fixed flange and the sliding flange in FIG. 1 and the extrusion device. [Diagram 3] FIG. 2 is a cross-sectional view showing the state during a water pressure test using the water pressure test device shown in FIG. [Figure 4]FIG. 11 is a cross-sectional view showing a second embodiment of the water pressure test device for a pipe joint according to the present invention (in a state before the water pressure test); [Diagram 5] FIG. 5 is a diagram showing the positional relationship between the fixed flange and the sliding flange in FIG. 4 and the extrusion device and the biasing member. [Figure 6] FIG. 5 is a cross-sectional view showing the state during a water pressure test using the water pressure test device shown in FIG. [Figure 7] FIG. 11 is a cross-sectional view showing a third embodiment of the water pressure test device for a pipe joint according to the present invention (in a state before the water pressure test); [Figure 8] A cross-sectional view showing the state during a water pressure test using the water pressure test device shown in Figure 7. [Figure 9] FIG. 11 is a cross-sectional view showing a fourth embodiment of the water pressure test device for a pipe joint according to the present invention (in a state before the water pressure test); [Figure 10] Cross-sectional view taken along line XX in Figure 9 [Figure 11] 10A is a cross-sectional view showing a piston used in the hydraulic test device shown in FIG. 9, where (a) is a first example, (b) is a second example, and (c) is a third example. [Figure 12] FIG. 10 is a cross-sectional view showing a state during a water pressure test using the water pressure test device shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] A first embodiment of a water pressure test device 1 for a pipe joint according to the present invention (hereinafter, abbreviated as water pressure test device 1) is shown in Figures 1 and 2. This water pressure test device 1 is an apparatus for checking the soundness (watertightness) of a watertight portion of a pipe joint in which an insertion-side pipe body 2 having an insertion port formed therein and a receiving-side pipe body 3 having a receiving port formed therein are watertightly joined via a watertight member 4.

[0021] This water pressure testing device 1 has as its main components a main body 5 extending along the pipe axis direction, a first water-stopping unit 6 provided on the outer surface of one end of the main body 5 in the pipe axis direction and capable of tightly fitting into the inner surface of the connected insertion side pipe 2 (one of the pipes) over the entire circumferential direction, a second water-stopping unit 7 provided on the outer surface of the other end of the main body 5 in the pipe axis direction and capable of tightly fitting into the inner surface of the connected receiving side pipe 3 (the other pipe) over the entire circumferential direction, and an extrusion device 8 that generates an extrusion force along the pipe axis direction.

[0022] The main body 5 is a cylindrical steel member, and inner flanges 9 that rise radially inward are formed on the inner surface of both ends in the pipe axis direction at a predetermined angular interval in the circumferential direction. Wheels 10 are provided on both ends in the pipe axis direction of the main body 5. These wheels 10 allow the hydraulic test device 1 to be freely moved to any position along the pipe axis direction.

[0023] The first water-stopping unit 6 and the second water-stopping unit 7 have a fixed flange 11 fixed to the outer surface of the main body 5, a sliding flange 12 spaced apart in the pipe axis direction from the fixed flange 11 which can slide in the pipe axis direction along the outer surface of the main body 5 by the pushing force of the extrusion device 8, and an elastic ring 13 which is arranged to straddle the fixed flange 11 and the sliding flange 12 and deforms outward as the fixed flange 11 and the sliding flange 12 approach each other in the pipe axis direction to abut against the inner surface of the insertion side pipe 2 or the receiving side pipe 3.

[0024] The fixing flange 11 is an annular plate-shaped member having an outer diameter smaller than the inner diameter of the insertion side pipe 2 and the receiving side pipe 3, and having a through hole with an inner diameter smaller than the inner diameter of the main body 5. An inclined surface is formed on the outer periphery of the fixing flange 11, the thickness of which in the pipe axial direction decreases toward the outer periphery. The fixing flange 11 of the first water stop unit 6 is fixed with bolts 14 to an inner flange 9 formed on one end side of the main body 5 (left side in FIG. 1). The fixing flange 11 of the second water stop unit 7 is fixed with bolts 14 to an inner flange 9 formed on the other end side of the main body 5 (right side in FIG. 1).

[0025] The sliding flange 12 is an annular plate-shaped member having an outer diameter smaller than the inner diameters of the insertion-side tube 2 and the receiving-side tube 3, and a through hole with an inner diameter slightly larger than the outer diameter of the main body 5. An inclined surface is formed on the outer periphery of the sliding flange 12, the thickness of which in the axial direction of the tube decreases toward the outer periphery. The inclined surfaces formed on the pair of fixed flanges 11 and sliding flanges 12 are inclined in opposite directions, and the two inclined surfaces form a substantially V-shape. A water-stopping material 15 is provided between the sliding flange 12 and the outer surface of the main body 5.

[0026] The elastic ring 13 is a rubber ring with an approximately U-shaped circumferential cross section, having a protruding portion 16 that protrudes toward the inner walls of the insertion side tube body 2 and the receiving side tube body 3 beyond the clamping region (the region indicated by arrow A in Figure 1) where it is clamped in the pipe axis direction between the fixed flange 11 and the sliding flange 12, and a recess 17 formed within the clamping region and on the pipe axis side of the protruding portion 16.

[0027] In its contracted state, the elastic ring 13 has a rounded shape along the tube axis, with the central portion thereof approaching the inner walls of the tube bodies 2, 3 and both ends thereof being slightly spaced apart from the inner walls of the tube bodies 2, 3. One end of the elastic ring 13 along the tube axis is fixed to the fixed flange 11, and the other end is fixed to the sliding flange 12, each by means of adhesion or the like.

[0028] The pushing device 8 is a hydraulic cylinder provided between the first water-stopping unit 6 and the second water-stopping unit 7 on the outer surface side of the main body 5. The pushing device 8 has a cylindrical cylinder body 18 and two pistons 19 provided inside the cylinder body 18. A rod 20 is connected to each piston 19, and one rod 20 is connected to the sliding flange 12 of the first water-stopping unit 6, and the other rod 20 is connected to the sliding flange 12 of the second water-stopping unit 7.

[0029] A cylinder piping 21 is connected to the space between both pistons 19 in the cylinder body 18, and working water pressurized to a predetermined pressure is supplied through this cylinder piping 21. In this embodiment, one extrusion device 8 is provided above and one below the center of the tube axis, but the number and arrangement thereof can be changed as appropriate.

[0030] In this embodiment, a hydraulic cylinder is used as the extrusion device 8, but other types of cylinders such as a hydraulic cylinder or a pneumatic cylinder, or a screw-type drive device using an electric motor may also be used.

[0031] On the lower side between the first water-stopping unit 6 and the second water-stopping unit 7, there is a water-filling pressurization pipe 22 that supplies pressurized water to the sealed space formed by the main body 5, both water-stopping units 6, 7, and the connected insertion side pipe 2 and receiving side pipe 3, and on the upper side, there is an air vent pipe 23 that exhausts air from within the sealed space.

[0032] The state during a water pressure test using the water pressure test device 1 according to this embodiment is shown in Fig. 3. After the water pressure test device 1 is moved to the joint portion of the two pipes 2, 3, working water is supplied from the cylinder piping 21 into the cylinder body 18 (between the two pistons 19). Then, the water pressure of the working water moves the two pistons 19 in the axial direction of the pipe so as to separate them.

[0033] As the pistons 19 move, each sliding flange 12 approaches its corresponding fixed flange 11 in the axial direction. Then, the elastic ring 13 provided to straddle the fixed flange 11 and the sliding flange 12 deforms so as to protrude radially outward and comes into contact with the inner surfaces of both tubular bodies 2, 3. At this time, the elastic ring 13 hardly moves in the axial direction, so no wear occurs due to sliding between the elastic ring 13 and the inner surfaces of both tubular bodies 2, 3.

[0034] The elastic ring 13 is easily deformed by a small force when the fixed flange 11 and the sliding flange 12 approach each other in the pipe axis direction because of the projection 16 and the recess 17, and can be easily expanded in diameter toward the inner walls of both pipes 2 and 3. This makes it possible to smoothly ensure a tight contact state between the elastic ring 13 and the inner walls of both pipes 2 and 3. In addition, the deformation of the elastic ring 13 occurs when the fixed flange 11 and the sliding flange 12 press the elastic ring 13 from both sides in the pipe axis direction, and does not apply a force that stretches the elastic ring 13 outward in the radial direction, so that the elastic ring 13 is less likely to deteriorate due to repeated use. In addition, the driving force of the sliding flanges 12 of both water stop units 6 and 7 is shared by the extrusion device 8 provided between both water stop units 6 and 7, so that the pressing force acting from the elastic rings 13 of both water stop units 6 and 7 on the inner surfaces of both pipes 2 and 3 can be equalized to ensure higher watertightness.

[0035] When the elastic ring 13 of the first water stop unit 6 abuts against the inner surface of the insertion side pipe 2 and the elastic ring 13 of the second water stop unit 7 abuts against the inner surface of the receiving side pipe 3, an airtight space is formed by the main body 5, both water stop units 6, 7, and the connected insertion side pipe 2 and receiving side pipe 3. This airtight space can be filled with pressurized water pressurized to a predetermined pressure (e.g., 0.5 MPa) by supplying pressurized water from the water filling pressurization pipe 22 to this airtight space and removing air accumulated in the upper part of the airtight space from the air vent pipe 23. After pressurization to the predetermined pressure, it is maintained for a predetermined time (e.g., 5 minutes), and the watertightness is judged based on whether the predetermined test water pressure (e.g., 0.4 MPa or more) can be maintained.

[0036] When the hydraulic test at the joint is completed, the supply of working water to the pressing device 8 (hydraulic cylinder) is cut off, the fixed flange 11 and the sliding flange 12 are separated, and the elastic ring 13 is contracted, so that the elastic ring 13 is separated from the inner surfaces of both pipes 2 and 3. This allows the pressurized water filled in the sealed space to be drained from the sealed space. In this embodiment, the hydraulic cylinder used as the extrusion device 8 is a single-acting type that can apply pressure from one side and only in the direction to push the internal piston (not shown) in the discharge direction, but by using a double-acting type equipped with piping that pressurizes the internal piston in both the pushing direction and the returning direction, the sliding flange 12 can be forced to return to its original position, and the elastic ring 13 can be contracted more smoothly. Therefore, the hydraulic test device 1 can be quickly moved to the next test location (joint portion), which improves the ease of carrying out the hydraulic test, and prevents wear caused by the elastic ring 13 sliding against the inner surfaces of the pipes 2 and 3.

[0037] Since one end of the elastic ring 13 in the pipe axis direction is fixed to the fixed flange 11 and the other end is fixed to the sliding flange 12, by separating the fixed flange 11 and the sliding flange 12 after completion of the hydrostatic test, both ends are forcibly pulled in the pipe axis direction, and the diameter of the elastic ring 13 can be smoothly reduced. In addition, since the elastic ring 13 has a rounded shape along the pipe axis direction, it is possible to prevent the end of the elastic ring 13 in the pipe axis direction from getting caught on the joint of the pipes 2, 3 when the hydrostatic test device 1 is moved in the pipe axis direction in the reduced diameter state.

[0038] A second embodiment of the water pressure testing apparatus 1 according to the present invention is shown in Figures 4 and 5. This water pressure testing apparatus 1 has a basic configuration in common with the water pressure testing apparatus 1 according to the first embodiment, but differs in that a biasing member 24 is provided between the fixed flange 11 and the sliding flange 12 of the first water stop unit 6 and the second water stop unit 7, for biasing the flanges 11, 12 in a direction separating them. An elastic body such as a spring can be used as this biasing member 24. In the following explanations of each embodiment, explanations of parts common to the water pressure testing apparatus 1 according to the first embodiment will be omitted.

[0039] FIG. 6 shows the state during the water pressure test by the water pressure test device 1 according to this embodiment. In the water pressure test using the water pressure test device 1, as described above, the supply of working water to the pressing device 8 (water pressure cylinder) is cut off at the completion of the water pressure test, the fixed flange 11 and the sliding flange 12 are separated, and the elastic ring 13 is reduced in diameter, so that the elastic ring 13 is separated from the inner surfaces of both pipes 2 and 3. In this embodiment, since the biasing member 24 is provided between both flanges 11 and 12, the biasing force of the biasing member 24 causes the fixed flange 11 and the sliding flange 12 to quickly separate, and the elastic ring 13 is reduced in diameter. Therefore, when the water pressure test device 1 is moved to the next test position (joint), the elastic ring 13 does not slide against the inner surfaces of both pipes 2 and 3, and the water pressure test device 1 can be moved smoothly. Therefore, the workability of the water pressure test can be improved, and wear caused by the sliding of the elastic ring 13 can be prevented.

[0040] In this embodiment, a single-acting push-out device 8 is used as in the first embodiment, but a double-acting push-out device 8 can also be used. In this way, even if the action of the biasing member 24 is insufficient, the sliding flange 12 can be reliably returned to its original position.

[0041] A third embodiment of the hydraulic test device 1 according to the present invention is shown in Fig. 7. This hydraulic test device 1 has a basic configuration in common with the hydraulic test device 1 according to the first embodiment, but differs in that a push-out device 8 (hydraulic cylinder) provided between the first water stop unit 6 and the second water stop unit 7 has link mechanisms 25 rotatable around a rotation axis provided on both ends of the push-out device 8 (hydraulic cylinder) provided between the first water stop unit 6 and the second water stop unit 7.

[0042] FIG. 8 shows a state during a water pressure test using the water pressure test device 1 according to this embodiment. In a water pressure test using this water pressure test device 1, a piston (not shown) is moved in the pipe axial direction by the water pressure of the working water supplied to the pushing device 8, and each sliding flange 12 is brought closer to the paired fixed flange 11. According to this configuration, since the link mechanism 25 can freely rotate about the rotation axis, for example, even if the insertion side pipe body 2 and the receiving side pipe body 3 are relatively bent in the pipe axial direction, the sliding flange 12 can be moved smoothly along the pipe axial direction of each pipe body 2, 3. In addition, since it is not necessary to fix the pushing device 8 to the main body 5, the structure can be simplified.

[0043] In this embodiment, a single-acting push-out device 8 is used as in the above-described embodiments, but a double-acting push-out device 8 can also be used. In this way, even if the action of the biasing member 24 is insufficient, the sliding flange 12 can be reliably returned to its original position.

[0044] A fourth embodiment of the hydraulic test apparatus 1 according to the present invention is shown in Fig. 9. The hydraulic test apparatus 1 has a basic configuration in common with the hydraulic test apparatus 1 according to the first embodiment, but differs in the configuration of the extrusion device 8. That is, the extrusion device 8 has an inner tube 26 integral with the main body 5, an outer tube 27 coaxially provided outside the inner tube 26, and two annular pistons 28 provided between the inner tube 26 and the outer tube. As shown in Fig. 10, between the inner tube 26 and the outer tube 27, supports 29 that connect both tubes 26, 27 are provided at predetermined angular intervals in the circumferential direction (every 90 degrees in this figure).

[0045] As shown in Fig. 11(a), rods 30 protruding in the axial direction are provided at predetermined angular intervals (every 90 degrees in this figure) in the circumferential direction of the annular piston 28. Instead of this configuration, as shown in Fig. 11(b), an annular member 33 may protrude in the axial direction from the annular piston 28, or as shown in Fig. 11(c), an annular member 33 may protrude in the axial direction from an elastic body such as rubber that serves as the annular piston 28.

[0046] The state during a water pressure test using the water pressure test device 1 according to this embodiment is shown in Fig. 12. With this configuration, the pressure-receiving area of ​​the piston 28 can be made larger than that of the water pressure test device 1 according to the first to third embodiments, so that a large force can be applied to the sliding flange 12 toward the fixed flange 11 even if the pressure of the working water supplied to the extrusion device 8 is small.

[0047] In this embodiment, a single-acting push-out device 8 is used as in the above-described embodiments, but a double-acting push-out device 8 can also be used. In this way, even if the action of the biasing member 24 is insufficient, the sliding flange 12 can be reliably returned to its original position.

[0048] In each of the above embodiments, the extrusion device 8 is provided between the two water-stopping units 6, 7, and this extrusion device 8 moves the sliding flanges 12 of both water-stopping units 6, 7. However, for example, it is also possible to provide an extrusion device 8 for each water-stopping unit 6, 7, and use each extrusion device 8 to move the sliding flanges 12 of each water-stopping unit 6, 7 individually, or to provide the extrusion device 8 outside the two water-stopping units 6, 7, and move the sliding flanges 12 of both water-stopping units 6, 7 via a link mechanism provided on this extrusion device 8.

[0049] In addition, in the configurations according to the second to fourth embodiments, a biasing member 24 is interposed between the fixed flange 11 and the sliding flange 12, but similar to the first embodiment, a configuration not including the biasing member 24 can also be used.

[0050] The above-described water pressure test device 1 is particularly suitable for water pressure testing of small diameter pipes, but can also be applied without any problems to water pressure testing of large diameter pipes.

[0051] The embodiments disclosed herein are illustrative in all respects and should not be considered as limiting. Therefore, the scope of the present invention is defined by the claims, not by the above description, and is intended to include the meaning equivalent to the claims and all modifications. [Explanation of symbols]

[0052] 1. Hydraulic test equipment for pipe joints (hydraulic test equipment) 2 Tube (insertion tube body) 3 Tube (receiving tube) 4. Water-stopping materials 5 Main body 6 First water stop unit 7 Second water stop unit 8 Extrusion Equipment 9 Inner flange 10 wheels 11 Fixed flange 12 Sliding flange 13 Elastic ring 14 Volts 15 Water-stopping materials 16 Extension 17 Recess 18 Cylinder body 19 Piston 20 Rod 21 Cylinder piping 22 Water filling and pressurization piping 23 Air vent pipe 24 Pressing member 25 Link mechanism 26 Inner cylinder 27 Outer cylinder 28 Piston 29 Post 30 Rod 31 Cylinder water filling and pressurization piping 32 Cylinder air vent pipe 33 Annular member

Claims

1. A main body portion (5) extending along the tube axis direction; a first water-stopping unit (6) provided on an outer surface of one end of the body portion (5) in the pipe axial direction and capable of tightly fitting to an inner surface of one of the connected pipes (2) over the entire circumference in the circumferential direction; a second water-stopping unit (7) provided on an outer surface of the other end of the main body (5) in the pipe axial direction and capable of tightly contacting an inner surface of the other connected pipe (3) over the entire circumference in the circumferential direction; An extrusion device (8) that generates an extrusion force along the tube axial direction; the first water-stopping unit (6) and the second water-stopping unit (7) have a fixed flange (11) fixed to the outer surface of the main body portion (5), a sliding flange (12) that is slidable along the outer surface of the main body portion (5) in the pipe axis direction by the pushing force of the extrusion device (8) and is provided spaced apart from the fixed flange (11) in the pipe axis direction, and an elastic ring (13) that is provided to straddle the fixed flange (11) and the sliding flange (12) and that deforms outward as the fixed flange (11) and the sliding flange (12) approach each other in the pipe axis direction to abut against the inner surface of the pipe (2, 3), a pair of inclined surfaces formed on the fixed flange (11) and the sliding flange (12) at their outer peripheries, the inclination directions of the inclined surfaces formed on each of the pair of fixed flanges (11) and the sliding flange (12) being opposite to each other, and the two inclined surfaces form an approximate V-shape in which the width in the pipe axial direction increases toward the inner surface of the one pipe (2) or the inner surface of the other pipe (3); and one end of the elastic ring (13) in the pipe axial direction is fixed to the inclined surface formed on the fixed flange (11), and the other end of the elastic ring (13) in the pipe axial direction is fixed to the inclined surface formed on the sliding flange (12).

2. 2. The water pressure testing device for a pipe joint according to claim 1, wherein the pushing device (8) is provided between the first water stop unit (6) and the second water stop unit (7).

3. 3. The hydraulic testing device for a pipe joint as described in claim 1 or 2, wherein the extrusion device (8) is a cylinder having an inner tube (26) integral with the main body portion (5), an outer tube (27) coaxially provided outside the inner tube (26), and an annular piston (28) provided between the inner tube (26) and the outer tube (27).

4. 4. The water pressure testing device for a pipe joint according to claim 1, further comprising a biasing member (24) between the fixed flange (11) and the sliding flange (12) for biasing the two flanges (11, 12) in a direction separating them.

5. 5. The water pressure testing device for a pipe joint according to claim 1, wherein the elastic ring (13) has a protruding portion (16) that protrudes toward the inner wall of the pipes (2, 3) beyond a clamping region that is clamped in the pipe axial direction by the fixed flange (11) and the sliding flange (12), and a recess (17) formed within the clamping region and on the pipe axial center side of the protruding portion (16).

6. A main body portion (5) extending along the tube axial direction, a first water-stopping unit (6) provided on an outer surface of one end of the body portion (5) in the pipe axial direction and capable of tightly fitting to an inner surface of one of the connected pipes (2) over the entire circumference in the circumferential direction; a second water-stopping unit (7) provided on an outer surface of the other end of the main body (5) in the pipe axial direction and capable of tightly contacting an inner surface of the other connected pipe (3) over the entire circumference in the circumferential direction; An extrusion device (8) that generates an extrusion force along the tube axial direction; the first water-stopping unit (6) and the second water-stopping unit (7) have a fixed flange (11) fixed to the outer surface of the main body portion (5), a sliding flange (12) provided spaced apart in the pipe axis direction from the fixed flange (11) and capable of sliding in the pipe axis direction along the outer surface of the main body portion (5) by the extrusion force of the extrusion device (8), and an elastic ring (13) provided to straddle the fixed flange (11) and the sliding flange (12) and deforms outward as the fixed flange (11) and the sliding flange (12) approach each other in the pipe axis direction to abut against the inner surface of the pipe (2, 3), The extrusion device (8) is a cylinder, and includes an inner tube (26) integral with the main body portion (5), an outer tube (27) coaxially provided outside the inner tube (26), and an annular piston (28) provided between the inner tube (26) and the outer tube (27).

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