JP2014094400A - Metal pipe expansion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal pipe expansion device capable of deforming even a metal pipe after installation to expand in the radial direction.SOLUTION: A metal pipe expansion device 100 is inserted into a steel pipe pile 30 consisting of a metal pipe to expand toward the outside in the pipe diameter direction and comprises a cylinder 1, a piston 2 arranged in the cylinder 1 in a slidable way and forming a hydraulic oil chamber 6 containing a hydraulic oil between the piston 2 and the cylinder 1, a shaft 4 for pressing and a pressing plate 10 connected to the piston 2 in such a way as to be integrally movable and extending out of the cylinder, a resin ring 9 held between the pressing plate 10 and the cylinder 1, a hydraulic pump 23 supplying a hydraulic oil to the hydraulic oil chamber 6 and first to fourth hydraulic oil passages 3d, 2d, 4d and 4e. When the piston 2 slides so as to increase the capacity of the hydraulic chamber 6, the pressing plate 10 presses the resin ring 9 toward the cylinder 1 to compress, and the resin ring 9 deforms in such a way as to be swelled toward the outside in the pipe diameter direction of the steel pipe pile 30.

Description

  The present invention relates to a metal tube expansion device capable of expanding a metal tube in a radial direction.

  Various techniques for processing metal tubes have been proposed. For example, Patent Document 1 describes an apparatus for manufacturing a metal bellows tube. This device has a ring-shaped split mold that is inserted into a metal tube and can be expanded in the radial direction of the tube, and a polygonal frustum shape that can be fitted to the inner peripheral surface of the ring-shaped split mold and has a ring shape. And a polygonal frustum-shaped part inserted into the inside of the metal tube together with the split mold. By pulling the extension rod connected to the polygonal frustum-shaped part in the metal tube toward the outside of the metal tube, and pressing the polygonal frustum-shaped part against the inner peripheral surface of the ring-shaped split mold in the metal tube, the ring shape The split mold is mechanically expanded in the pipe radial direction, so that the ring-shaped split mold engages with the metal pipe and pushes the metal pipe outward in the pipe radial direction to expand the diameter. Furthermore, the apparatus described in Patent Document 1 has two divided outer molds attached to the outer peripheral surface of the metal tube. After expanding the diameter of the metal tube, if the polygonal frustum-shaped part is moved away from the ring-shaped divided mold, the ring-shaped divided mold is reduced in diameter and returned to its original shape, and is annularly formed along the circumferential direction of the metal tube. The engagement with the formed enlarged diameter portion is released. After that, a bellows node is formed by sandwiching and crushing the enlarged diameter portion of the metal tube from both sides with a split outer die.

JP-A-11-169958

  In the apparatus described in Patent Document 1, a hollow shaft surrounding the outer peripheral surface of the extension is provided, and the hollow shaft prevents movement of the ring-shaped split mold in the axial direction. The hollow shaft is fixed to the gantry and supports a ring-shaped split mold that is pushed by the polygonal frustum-shaped portion. Thus, the apparatus described in Patent Document 1 requires a support member such as a hollow shaft that supports the ring-shaped split mold that receives the tensile force from the extension rod, and a fixing means such as a gantry that fixes the support member. Become. Therefore, since the device described in Patent Document 1 is used by being fixed to a fixed position and setting a metal pipe, the metal pipe after installation in equipment or the like, and the metal pipe after placement as a steel pipe pile There is a problem that such an already fixed metal tube cannot be processed.

  The present invention has been made to solve such problems, and provides a metal tube expansion device that can be deformed so as to expand in the radial direction with respect to a metal tube after installation. With the goal.

  In order to solve the above-described problems, a metal tube expansion device according to the present invention is a metal tube expansion device that is inserted into a metal tube and expands the metal tube toward the outside in the radial direction of the tube. A piston that is provided between the cylinder and a working fluid chamber that includes a working fluid, is connected to the piston so as to be movable integrally, and extends outside the cylinder; and between the pressing member and the cylinder When the piston slides so as to increase the volume of the working fluid chamber, the pressing member moves the deformable member into the cylinder. The deformable member is deformed so as to bulge toward the outside in the radial direction of the metal tube.

The metal tube expansion device may further include a biasing unit that applies a biasing force to the piston to move the volume of the working fluid chamber in a direction to reduce the volume.
The pressing member is connected to the piston so as to be movable integrally, extends to the outside of the cylinder along the sliding direction of the piston and penetrates the deformable member, and the pressing shaft penetrates the deformable member. And a pressing plate that is connected to the end of the cylinder and sandwiches the deformable member with the cylinder.
The working fluid supply means may include a working fluid pumping device that pumps the working fluid and a working fluid flow path that communicates the working fluid pumping device with the working fluid chamber through the inside of the piston.

  According to the metal tube expansion device according to the present invention, it is possible to deform the metal tube after installation so as to expand in the radial direction.

1 is a cross-sectional side view of a metal tube expansion device according to an embodiment of the present invention. It is a cross-sectional side view which shows the state at the time of metal pipe expansion in the metal pipe expansion apparatus of FIG. It is a cross-sectional side view which shows the state of the steel pipe pile expanded by using the metal pipe expansion apparatus of FIG. 1 after penetrating into the ground.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
Embodiment First, the configuration of a metal tube expansion device 100 according to an embodiment of the present invention will be described.
Referring to FIG. 1, a metal tube expansion device 100 includes a metal tube expansion device main body 101 inserted into a metal tube. The metal tube expansion device main body 101 includes a cylindrical metal cylinder 1 and a cylinder 1 inside. And a metal piston 2 that is slidable.

The cylinder 1 is formed with a through hole penetrating the cylinder 1 along the cylindrical axis direction from the end 1a toward the end 1b. The inner diameter of the through hole changes in the middle along the cylindrical axis direction, and is configured by a cylindrical cylinder hole portion 1c on the large diameter side and a cylindrical shaft hole portion 1d on the small diameter side. .
The cylinder hole 1c is opened at the end 1a, and an internal thread 1ca is formed along the circumferential direction on the inner peripheral surface near the end 1a.
The shaft hole portion 1d is adjacent to the cylinder hole portion 1c in the axial direction and opens at the end portion 1b, and communicates with the cylinder hole portion 1c on the side opposite to the end portion 1b. An annular shaft seal groove 1e is formed along the circumferential direction on the inner peripheral surface of the shaft hole portion 1d, and an annular shaft seal 1f made of an elastic material is fitted in the shaft seal groove 1e. .

The piston 2 has a cylindrical shape and is disposed in the cylinder hole 1c.
An end portion 3b of a substantially cylindrical conduit shaft 3 is integrally connected to the end portion 2a of the piston 2 on the end portion 1a side. The conduit shaft 3 extends to the outside from the cylinder hole portion 1c, and is connected to the opposite side. The end 3a is projected outside the cylinder 1.
An end portion 4a of a cylindrical metal pressing shaft 4 is integrally connected to the end portion 2b of the piston 2 on the end portion 1b side. The pressing shaft 4 extends from the cylinder hole 1c through the shaft hole 1d to the outside of the cylinder 1, and the opposite end 4b protrudes outside the cylinder 1. A male screw 4ba is formed in the vicinity of the end 4b of the cylindrical outer peripheral surface 4c of the pressing shaft 4 along the circumferential direction. Further, in the shaft hole portion 1d, the shaft seal 1f contacts the cylindrical outer peripheral surface 4c of the pressing shaft 4 and seals the space between the pressing shaft 4 and the cylinder 1 in a watertight manner.
The pressing shaft 4, the piston 2, and the conduit shaft 3 are arranged in a line in a straight line.

An annular piston seal groove 2e is formed along the circumferential direction on the cylindrical outer peripheral surface 2c of the piston 2, and an annular piston seal 2f made of an elastic material is fitted in the piston seal groove 2e. In the cylinder hole 1c, the piston seal 2f contacts the inner peripheral surface of the cylinder hole 1c and seals the space between the piston 2 and the cylinder 1 in a watertight manner.
Therefore, on the side of the end 2b of the piston 2 in the cylinder hole 1c, a cylindrical operation sealed between the piston 2 and the pressing shaft 4 and the cylinder 1 by the shaft seal 1f and the piston seal 2f. An oil chamber 6 is formed. The hydraulic oil chamber 6 is configured to be supplied with hydraulic oil as a working fluid. In the hydraulic oil chamber 6, the piston 2 together with the pressing shaft 4 and the conduit shaft 3 pass through the cylinder hole 1 c. The volume is changed by sliding in the direction of the cylindrical axis.
Here, the hydraulic oil chamber 6 constitutes a working fluid chamber.

The piston 2 is formed with a second hydraulic fluid passage 2d that penetrates the piston 2 in the cylindrical axis direction from the end 2a to the end 2b.
Further, the conduit shaft 3 is formed with a first hydraulic oil passage 3d that penetrates the conduit shaft 3 in the axial direction from the end 3b to the opposite end 3a. The first hydraulic fluid passage 3d communicates with the second hydraulic fluid passage 2d on the end 3b side, and opens on the end 3a side. The first hydraulic oil passage 3d includes an enlarged diameter portion 3da that is enlarged in the radial direction perpendicular to the axial direction in the vicinity of the end portion 3a, and a female screw is formed on the inner peripheral surface of the enlarged diameter portion 3da. .

  Further, the pressing shaft 4 is formed with a third hydraulic oil passage 4d extending from the end 4a to the middle of the inside along the cylinder axis direction. The third hydraulic oil passage 4d communicates with the second hydraulic oil passage 2d at the end 4a. Further, in the pressing shaft 4, a plurality of fourth hydraulic oil passages 4 e extending in the radial direction from the third hydraulic oil passage 4 d and opening on the outer peripheral surface 4 c of the pressing shaft 4 are formed. The fourth hydraulic oil passage 4 e communicates the third hydraulic oil passage 4 d with the hydraulic oil chamber 6.

Further, the cylinder 1 is provided with a substantially cylindrical spring base cover 5 attached so as to close the end 1a.
The spring pedestal cover 5 includes a cylindrical male screw portion 5b having a male screw threadedly engaged with the female screw 1ca of the cylinder hole portion 1c on the outer peripheral surface, and a disk-like stopper portion 5a integrally provided adjacent to the male screw portion 5b. have. When the male screw portion 5b is screwed into the female screw 1ca of the cylinder hole portion 1c and tightened, the stopper portion 5a contacts the end portion 1a of the cylinder 1 and stops tightening. Further, the spring pedestal lid 5 is formed with a conduit shaft hole 5c that penetrates the stopper portion 5a and the male screw portion 5b in the cylindrical axis direction. The conduit shaft hole 5c has a shape aligned with the outer peripheral surface 3c of the conduit shaft 3, and is configured so that the conduit shaft 3 is slidably passed therethrough.

In the cylinder hole 1c, a coil spring 8 as an urging means is provided in a space 7 between the piston 2 and the spring base lid 5 so as to surround the conduit shaft 3. The coil spring 8 is in contact with the end portion 5ba of the male screw portion 5b of the spring base lid 5 on the space 7 side and the end portion 2a of the piston 2, and is pulled away from the spring base lid 5 with respect to the piston 2, that is, a hydraulic oil chamber. The elastic force is applied in the direction of decreasing the volume of 6.
Further, the metal tube expansion device main body 101 includes a substantially cylindrical resin ring 9 through which the pressing shaft 4 is passed and the end 9 a is brought into contact with the end 1 b of the cylinder 1, and the pressing shaft 4. And a disc-shaped pressing plate 10 disposed so that the surface 10a is brought into contact with the end 9b opposite to the end 9a of the resin ring 9.

The resin ring 9 can be deformed when subjected to a force such as hard urethane, but is formed from a resin having such a hardness that the steel plate can be deformed by being pressed at least under compression and with increased hardness. Has been. The resin ring 9 has the pressing shaft 4 passed through the through hole 9d that penetrates the resin ring 9 from the end 9a to the end 9b. The through hole 9d has an inner diameter that matches the outer diameter of the pressing shaft 4. ing. Further, the outer diameter of the outer peripheral surface 9c of the central portion of the resin ring 9 is larger than the outer diameter of the outer peripheral surface in the vicinity of the end portions 9a and 9b, and is less than or equal to the outer diameter of the cylinder 1. ing.
Here, the resin ring 9 constitutes a deformable member.

The pressing plate 10 is made of metal, and the pressing shaft 4 is passed through the through hole 10c penetrating the pressing plate 10 from the surface 10a to the opposite surface 10b, and the through hole 10c has an outer diameter of the pressing shaft 4. It has a matching inner diameter. Further, the outer diameter of the pressing plate 10 is the same as the outer diameter of the cylinder 1. Therefore, the pressing plate 10 can press the entire end portion 9b of the resin ring 9 toward the cylinder 1, and at this time, the resin ring 9 causes the entire end portion 9a to contact the end portion 1b of the cylinder 1. And compressed in the axial direction.
The resin ring 9 and the pressing plate 10 can slide in the axial direction on the pressing shaft 4.
Here, the pressing shaft 4 and the pressing plate 10 constitute a pressing member.

In addition, the metal tube expansion device main body 101 includes a hexagonal nut-like fastener 11 that is passed through the pressing shaft 4 and screwed into the male screw 4ba and is adjacent to the surface 10b of the pressing plate 10, and a pressing shaft. 4 has a hexagonal nut-like tip member 12 that is threadedly engaged with the male screw 4ba and is disposed adjacent to the fastener 11 on the tip side of the end 4b.
The fastener 11 has a female screw hole 11 a penetrating the fastener 11, and the radial size is not more than the pressing plate 10. The fastener 11 can press the pressing plate 10 and the resin ring 9 toward the cylinder 1 by screwing the female screw hole 11a into the male screw 4ba of the pressing shaft 4 and tightening the fastener.

  The tip member 12 has a female screw hole 12a penetrating the tip member 12, and the size in the radial direction is not more than the pressing plate 10. The tip member 12 is engaged with the fastener 11 by fastening the female screw hole 12a to the male screw 4ba of the pressing shaft 4 and tightens to fix the fastener 11 in the screw rotation direction. . In this embodiment, the pressing plate 10 is brought into contact with the resin ring 9 and the resin ring 9 is brought into contact with the cylinder 1, but the fastener 11 is fixed at a position where the pressing plate 10 does not compress the resin ring 9. Is done.

  Therefore, from the cylinder 1, the resin ring 9, the pressing plate 10, the fastener 11, and the tip member 12 are arranged in a straight line in this order with the pressing shaft 4 being coaxial. The piston 2, the conduit shaft 3, the pressing shaft 4, the fastener 11, and the tip member 12 can be integrated and reciprocate in the cylindrical axis direction with respect to the cylinder 1.

The metal pipe expansion device 100 includes a hydraulic pump 23 (in this embodiment, a manual hydraulic pump, see FIG. 3), a flexible hydraulic pipe 22 extending from the hydraulic pump 23, and a hydraulic pipe 22. And a connecting fitting 21 at the tip of the head.
The connecting fitting 21 can be connected to the enlarged diameter portion 3da of the conduit shaft 3 in the metal pipe expansion device main body 101.
The coupling fitting 21 can be connected to the conduit shaft 3 by screwing the outer peripheral surface 21a on which the male screw is formed with the female screw of the enlarged diameter portion 3da. The connection fitting 21 communicates the inside of the hydraulic piping 22 to the first hydraulic fluid passage 3d through a communication hole 21b penetrating the inside.

Therefore, in the metal pipe expansion device main body 101, the hydraulic fluid that is the hydraulic fluid pumped from the hydraulic pump 23 (see FIG. 3) is supplied from the first hydraulic fluid passage 3d to the second to fourth hydraulic fluid passages 2d, 4d, and 4e. Are sequentially supplied into the hydraulic oil chamber 6.
Here, the hydraulic pump 23 constitutes a working fluid supply means and a working fluid pumping device, and the first to fourth working oil passages 3d, 2d, 4d and 4e constitute a working fluid supply means and a working fluid flow path. ing.

Next, the operation of the metal tube expansion device 100 according to the embodiment of the present invention will be described.
Referring to FIG. 1, in the metal pipe expansion device main body 101 of the metal pipe expansion device 100, when hydraulic oil is not supplied from the hydraulic pipe 22, the hydraulic pressure in the hydraulic oil chamber 6 is lowered, and the elasticity of the coil spring 8 is applied to the piston 2. Since the force acts above the hydraulic pressure, the piston 2 is moved toward the resin ring 9 and the volume of the hydraulic oil chamber 6 is reduced. At this time, the resin ring 9 does not receive a pressing force from the pressing plate 10 and the cylinder 1 and maintains a normal state.

  When the hydraulic oil is supplied from the hydraulic pipe 22 by the hydraulic pump 23 (see FIG. 3), the supplied hydraulic oil passes through the first to fourth hydraulic oil passages 3d, 2d, 4d, and 4e, and the hydraulic oil chamber. 6 flows in. As a result, the hydraulic pressure in the hydraulic oil chamber 6 increases, and the increased hydraulic pressure presses the piston 2 toward the coil spring 8. When the pressing force due to the hydraulic oil pressure exceeds the elastic force of the coil spring 8, the hydraulic oil moves the piston 2 toward the spring base lid 5 while pressing and contracting the coil spring 8, thereby increasing the volume of the hydraulic oil chamber 6. At this time, the conduit shaft 3, the pressing shaft 4, the fastener 11, and the tip member 12 are also moved in the same direction together with the piston 2. Thereby, the pressing plate 10 is pressed toward the cylinder 1 by the fastener 11 and slides, and the resin ring 9 is compressed by the cylinder 1 and the pressing plate 10 from both end portions 9a and 9b.

  As shown in FIG. 2, the compressed resin ring 9 is deformed so as to protrude by expanding the outer peripheral surface 9 c in the radial direction of the cylinder while reducing the thickness in the cylindrical axis direction, that is, the diameter is increased. In the resin ring 9, since the outer diameter of the outer peripheral surface in the vicinity of the end portions 9a and 9b is smaller than the outer diameter of the outer peripheral surface 9c of the central portion, the end portion where the pressure receiving area is small and high pressure acts 9a and 9b can easily deform the resin ring 9 and push it outward in the radial direction, whereby the radial expansion rate of the resin ring 9 can be increased.

Then, when the supply of hydraulic oil by the hydraulic pump 23 (see FIG. 3) is stopped so that the hydraulic oil can return from the hydraulic pipe 22 toward the hydraulic pump 23, the hydraulic pressure in the hydraulic oil chamber 6 decreases. . When the elastic force in the extending direction of the coil spring 8 exceeds the hydraulic pressure, the piston 2 is moved toward the resin ring 9 by the elastic force, and the resin ring 9 increases in thickness and contracts in the radial direction. It returns to the normal state as shown in.
As described above, the metal pipe expansion device main body 101 can freely deform the resin ring 9 in the diameter expansion direction or the diameter reduction direction by controlling the hydraulic pressure acting in the hydraulic oil chamber 6.

Further, a method for expanding and deforming a metal tube using the metal tube expansion device 100 will be described. In addition, this Embodiment demonstrates the case where the metal pipe expansion apparatus 100 is used for the expansion deformation of the small diameter steel pipe pile (steel pipe pile whose outer diameter is about 100 mm) after penetrating into the ground as a metal pipe.
Referring to FIG. 3, in step (3A), a small-diameter single tubular steel pipe pile 30 whose end 30b at the front end of the underground side is blocked so that earth and sand do not enter the interior is a building pole car not shown. The construction machine is pressed into the supporting ground to a predetermined depth. At this time, since the steel pipe pile 30 is press-fitted into the ground that has not been drilled in advance, the steel pipe pile 30 moves downward in the ground while pushing the earth and sand in the ground to the periphery at the end of the closed end portion 30b. Intrude into.

Next, in the step (3B), the tip member 12 is placed in the steel pipe pile 30 from the opening portion of the end portion 30c protruding to the ground surface in the steel pipe pile 30 after the completion of the penetration to a predetermined depth to the lower side on the ground side ( The metal tube expansion device body 101 of the metal tube expansion device 100 (shown in side view) is inserted. The metal pipe expansion device body 101 is configured such that the outer diameter of the resin ring 9 is smaller than the inner diameter of the inner peripheral surface 30d of the steel pipe pile 30 when the resin ring 9 is in a normal state. At the time of insertion, a manual hydraulic pump 23 is connected to the conduit shaft 3 of the metal pipe expansion device main body 101 via a coupling fitting 21 and a hydraulic pipe 22.
In the steel pipe pile 30, when the metal pipe expansion device main body 101 is lowered to a predetermined position, the hydraulic pump 23 is operated and the hydraulic oil is pumped to the metal pipe expansion device main body 101.

  Referring also to FIG. 1, the hydraulic oil that has been pressure-fed is sent into the hydraulic oil chamber 6 of the metal pipe expansion device main body 101, and the hydraulic oil in the hydraulic oil chamber 6 whose hydraulic pressure has been increased presses the piston 2. The hydraulic oil chamber 6 is moved to increase the volume. As a result, the resin ring 9 is compressed by the pressing plate 10 and bulges so as to increase in diameter toward the outside in the pipe radial direction of the steel pipe pile 30. The bulging resin ring 9 pushes and expands the cylindrical peripheral wall 30a of the steel pipe pile 30 from the inner side toward the outer side in the pipe radial direction over the entire circumference of the inner peripheral surface 30d. Thereby, on the peripheral wall 30a of the steel pipe pile 30, a protruding portion 31 that partially bulges in the circumferential direction is formed like a node.

After the formation of the protruding portion 31 at the above-described position, when the hydraulic pump 23 is stopped and the pressurization to the hydraulic oil in the hydraulic oil chamber 6 is released, the pressing plate 10 is moved by the elastic force in the return direction of the coil spring 8. The piston 2 is moved in the direction away from the cylinder 1, and the bulging resin ring 9 returns to the normal state.
And the metal pipe expansion apparatus main body 101 is moved to the next predetermined position in the vertical direction in the steel pipe pile 30, and then the protruding portion is formed on the peripheral wall 30a of the steel pipe pile 30 by the metal pipe expansion apparatus main body 101 in the same manner as described above. 31 is formed. By repeating the formation of the protrusions 31 at predetermined intervals in the vertical direction, the construction of the steel pipe pile 30 having the plurality of protrusions 31 is completed as shown in the step (3C). In the present embodiment, the formation of the protruding portion 31 on the steel pipe pile 30 by the metal pipe expansion device main body 101 is sequentially performed so as to start from the deepest position in the ground and then rise toward the ground surface. That is, in the step (3B) of FIG. 2, for example, in the order from the step (3B1) of forming the protrusion 31 at a deeper position to the step (3B2) of forming the protrusion 31 at a shallower position. 31 is formed.

In addition, according to the metal pipe expansion apparatus main body 101 which can be freely moved to an axial direction within the steel pipe pile 30, formation of the protrusion part 31 to the steel pipe pile 30 is the underground side of the steel pipe pile 30 as mentioned above. The order from the end 30b to the end 30c on the ground surface side or the opposite order is possible.
Moreover, when the steel pipe pile 30 formed before the penetration of the plurality of nodular protrusions 31 is penetrated into the ground, the ground is disturbed over the range of the outer diameter of the projections 31 at the time of penetration. The ground becomes loose around the peripheral wall 30a, and the supporting force by the peripheral frictional force with the ground in the steel pipe pile 30 becomes low. However, the ground around the steel pipe pile 30 is not disturbed by forming the protrusion 31 on the steel pipe pile 30 using the metal pipe expansion device body 101 after the steel pipe pile 30 having no protrusion 31 is penetrated into the ground. Therefore, the steel pipe pile 30 can be installed without reducing the supporting force due to the circumferential frictional force.
Furthermore, in the steel pipe pile 30, since the protrusion part 31 was formed so that the outer diameter of the surrounding wall 30a might be expanded, a contact area with the ground will increase and circumferential surface frictional force will increase. Furthermore, the plurality of node-like protrusions 31 on the peripheral wall 30a serve as a movement resistance in the vertical direction, that is, there is an effect of increasing the supporting force of the steel pipe pile 30 with an anchor effect.

  As described above, the metal pipe expansion device 100 according to the embodiment of the present invention is inserted into the steel pipe pile 30 and expands the steel pipe pile 30 toward the outside in the pipe radial direction. The metal pipe expansion device 100 is slidably provided in the cylinder 1 and the piston 2 that forms a hydraulic oil chamber 6 including hydraulic oil between the cylinder 1 and the piston 2 and can move integrally with the piston 2. The pressure shaft 4 and the pressure plate 10 connected to the cylinder 1 and extending to the outside of the cylinder 1, the resin ring 9 sandwiched between the pressure plate 10 and the cylinder 1, and the hydraulic pump for supplying hydraulic oil to the hydraulic oil chamber 6 23, hydraulic piping 22, and first to fourth hydraulic oil passages 3d, 2d, 4d and 4e. When the piston 2 slides to increase the volume of the hydraulic oil chamber 6, the pressing plate 10 presses the resin ring 9 so as to compress it toward the cylinder 1, and the resin ring 9 has a pipe diameter of the steel pipe pile 30. Deforms to bulge outward in the direction.

  At this time, when the hydraulic oil is supplied from the hydraulic pump 23, the metal pipe expansion device main body 101 of the metal pipe expansion device 100 inserted into the steel pipe pile 30 raises the hydraulic pressure of the hydraulic oil chamber 6 and the hydraulic oil chamber. The piston 2 is slid so as to increase the volume of 6. Thereby, the resin ring 9 is expanded toward the outer side in the pipe radial direction, and the steel pipe pile 30 is pushed and expanded from the inner side to increase the diameter. For this reason, the metal pipe expansion device main body 101 does not need to fix and support the cylinder 1, the piston 2, etc. in addition to itself in the steel pipe pile 30, and is simply inserted into the steel pipe pile 30. Can be expanded. And if the metal pipe expansion apparatus main body 101 can be inserted in the inside of the steel pipe pile 30 from one open | released edge part, the steel pipe pile 30 can be expanded in diameter. Therefore, when the metal pipe expansion device 100 is used, it is possible to perform a process of expanding the metal pipe installed in the facility or the like in the radial direction in addition to the steel pipe pile 30 after penetrating into the ground.

  In addition, the metal pipe expansion device main body 101 includes a coil spring 8 that applies an urging force to the piston 2 to move the volume of the hydraulic oil chamber 6 in the direction of reducing the volume. Thus, when no hydraulic pressure is applied to the hydraulic oil chamber 6, the coil spring 8 automatically moves the piston 2 so as to reduce the volume of the hydraulic oil chamber 6, and the resin ring 9 is not compressed and does not bulge. Can be.

  Further, in the metal pipe expansion device main body 101, a member that presses the resin ring 9 is connected to the piston 2 so as to be movable integrally, and extends to the outside of the cylinder 1 along the sliding direction of the piston 2 and is also resin ring. And a pressing plate 10 that is connected to an end portion 4 b of the pressing shaft 4 that passes through the resin ring 9 and sandwiches the resin ring 9 with the cylinder 1. At this time, in the metal tube expansion device main body 101, the cylinder 1, the resin ring 9, and the pressing plate 10 are arranged in a line along the sliding direction of the piston 2, and the resin ring 9 is in a direction perpendicular to the sliding direction of the piston 2. It becomes the structure which bulges toward. Therefore, the metal pipe expansion device main body 101 can be downsized in the direction perpendicular to the sliding direction of the piston 2, that is, the pipe diameter direction of the steel pipe pile 30, and enables the small diameter steel pipe pile 30 to be expanded.

  In the metal pipe expansion device main body 101, a hydraulic pump 23 that pumps hydraulic oil, and first to fourth hydraulic oil passages 3d and 2d that communicate the hydraulic pump 23 with the hydraulic oil chamber 6 through the inside of the piston 2; The hydraulic oil is supplied to the hydraulic oil chamber 6 by 4d and 4e. At this time, the first to fourth hydraulic oil passages 3d, 2d, 4d, and 4e can be positioned on the inner side of the outer peripheral surface 2c of the piston 2 in the direction perpendicular to the sliding direction of the piston 2. Therefore, the metal pipe expansion device main body 101 enables downsizing in the direction perpendicular to the sliding direction of the piston 2, that is, in the pipe radial direction of the steel pipe pile 30.

Moreover, in the metal pipe expansion apparatus main body 101 of embodiment, although the manual hydraulic pump 23 was used as a means to pump hydraulic fluid, it is not limited to this, An electric type or a power type is not limited to this. There may be a pump.
Moreover, in the metal pipe expansion apparatus main body 101 of the embodiment, the hydraulic oil is supplied to the hydraulic oil chamber 6 as the hydraulic fluid. However, the present invention is not limited to this, and other liquids such as water are used. Alternatively, a gas such as air may be supplied, and the piston 2 may be operated by liquid pressure or gas pressure in the hydraulic oil chamber 6.
Moreover, although the metal pipe expansion apparatus main body 101 was used in order to partially expand the steel pipe pile 30 to a pipe radial direction outer side in embodiment, it can be widely used for metal pipes other than a steel pipe pile. The metal tube expansion device main body 101 can be used for any metal tube as long as one end is open.

Moreover, in embodiment, although the metal pipe expansion apparatus main body 101 was used for the small diameter steel pipe pile whose outer diameter is about 100 mm, it is not limited to this, It uses for the steel pipe whose outer diameter exceeds 100 mm May be.
Moreover, in embodiment, although the external shape of the front-end | tip part of the steel pipe pile 30 using the metal pipe expansion apparatus main body 101 was a column shape, it is not limited to this, The cone shape which tapers toward a front-end | tip, The shape may be a pyramid shape, a truncated cone shape, a truncated pyramid shape, or a spiral (drill) shape that tapers toward the tip.

  DESCRIPTION OF SYMBOLS 1 Cylinder, 2 Piston, 2d 2nd hydraulic oil path (working fluid supply means, working fluid flow path), 3d 1st hydraulic oil path (working fluid supply means, working fluid flow path), 4 Pressing shaft (pressing member) 4 d Third hydraulic oil passage (working fluid supply means, working fluid flow path), 4 e Fourth hydraulic oil passage (working fluid supply means, working fluid flow path), 6 hydraulic oil chamber (working fluid chamber), 8 coil spring ( Urging means), 9 resin ring (deformable member), 10 pressing plate (pressing member), 23 hydraulic pump (working fluid supply means, working fluid pumping device), 30 steel pipe pile (metal pipe), 100 metal tube expansion device 101 Metal tube expansion device body.

Claims (4)

In a metal tube expansion device that is inserted into a metal tube and expands the metal tube outward in the radial direction of the tube,
A cylinder,
A piston which is slidably provided in the cylinder and forms a working fluid chamber containing the working fluid with the cylinder;
A pressing member that is movably coupled to the piston and extends to the outside of the cylinder;
A deformable member sandwiched between the pressing member and the cylinder;
Working fluid supply means for supplying the working fluid to the working fluid chamber,
When the piston slides to increase the volume of the working fluid chamber, the pressing member presses the deformable member so as to compress it toward the cylinder, and the deformable member is A metal tube expansion device that deforms so as to bulge outward in the tube diameter direction.   The metal pipe expansion device according to claim 1, further comprising an urging unit that imparts an urging force to the piston to move the volume of the working fluid chamber in a direction to reduce the volume. The pressing member is
A pressing shaft that is movably coupled to the piston and extends outside the cylinder along a sliding direction of the piston and penetrates the deformable member;
The metal tube expansion device according to claim 1, further comprising: a pressing plate that is connected to an end portion of the pressing shaft that penetrates the deformable member and sandwiches the deformable member with the cylinder. The working fluid supply means includes
A working fluid pumping device for pumping the working fluid;
The metal pipe expansion device according to any one of claims 1 to 3, further comprising a working fluid flow path that communicates the working fluid pumping device with the working fluid chamber through the inside of the piston.

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