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CN-120845624-B - Shut-off system and fluid shut-off method

CN120845624BCN 120845624 BCN120845624 BCN 120845624BCN-120845624-B

Abstract

A cutting system of the present invention comprises a straight pipe made of a polyolefin material, and a knife blade having a semicircular arc-shaped first cutting edge for cutting the straight pipe to form a slit-shaped opening on the distal end side of the knife blade, a circular arc-shaped sealing portion for contacting the cut surface of the straight pipe on the proximal end side of the knife blade, the knife blade having a pair of side edge portions for connecting the first cutting edge and the sealing portion, the first cutting edge and the side edge portions penetrating into the inner peripheral surface along the inner peripheral surface of the straight pipe, the knife blade being formed in a flat plate shape having a first surface and a second surface between the first cutting edge and the sealing portion and between the pair of side edge portions, the opening extending in the circumferential direction in the straight pipe, the sealing portion extending from one end portion of the opening to the other end portion, and extending from the inner peripheral surface to the outermost peripheral surface of the straight pipe in a section from the one end portion to the other end portion.

Inventors

  • SATO TOSHIYUKI

Assignees

  • 株式会社水研

Dates

Publication Date
20260508
Application Date
20210219
Priority Date
20200305

Claims (9)

  1. 1. A cutting system is provided with a straight pipe (2) made of a polyolefin material, and a flat blade (1) for preventing the flow of a fluid in the straight pipe (2), A semicircular first cutting edge (13) is formed on the distal end side of the knife switch (1), the first cutting edge (13) cuts the straight tube (2) to form a slit-shaped opening (20) extending along the circumferential direction (R) of the straight tube (2) in a slender manner, A sealing part (14) in the shape of an arc band is formed on the proximal end side of the knife switch (1), the sealing part (14) is connected with the cutting surfaces (21, 22) of the straight tube (2) defining the opening (20), The knife switch (1) is provided with a pair of side edge parts (15, 15) connecting the semicircular first cutting edge (13) and the circular arc strip-shaped sealing part (14), The semicircular first cutting edge (13) and the pair of side edge parts (15, 15) of the knife switch (1) invade the inner peripheral surface (23) along the inner peripheral surface (23) of the straight tube (2), The knife switch (1) is formed in a flat plate shape having a first surface (11) and a second surface (12) on the opposite side of the first surface (11) between the first cutting edge (13) and the sealing portion (14) and between the pair of side edge portions (15, 15), The slit-shaped opening (20) extends in the straight tube (2) along a circumferential direction (R), The sealing part (14) of the knife switch (1) extends from one end (25) to the other end (26) of the opening (20) in the circumferential direction (R), and extends from the inner peripheral surface (23) to the outermost peripheral surface (24) of the straight tube (2) in the interval from the one end (25) to the other end (26) to form the circular arc strip shape, Second cutting edges (17) connected to the first cutting edge (13) are formed on the pair of side edge portions (15, 15), respectively, A stopper (16) is mounted on the knife switch (1), the stopper (16) is abutted against the outermost peripheral surface (24) of the straight tube (2), the first cutting edge (13) which is invaded into the half-peripheral portion of the inner peripheral surface (23) is prevented from further pushing cutting after the first cutting edge (13) is invaded into the inner peripheral surface (23) of the straight tube (2), The second cutting edge (17) extends to the stop (16).
  2. 2. The truncation system of claim 1, wherein, Two ends of the sealing part (14) which are connected with a pair of end parts (25, 26) of the opening (20) are sharp in a cutting edge shape.
  3. 3. The truncation system of claim 2, wherein, The device further comprises: a housing (30) surrounding a portion of the straight tube (2) and the knife switch (1), and And a valve rod (43) that moves the knife switch (1) until a first cutting edge (13) of the knife switch (1) disposed in the housing (30) cuts the straight tube (2) to form the opening (20), and the first cutting edge (13) penetrates along the inner peripheral surface (23).
  4. 4. The truncation system of claim 1, wherein, A width between the second cutting edges (17) formed on the pair of side edges (15, 15) is larger than an inner diameter (phi) of the straight pipe (2).
  5. 5. The truncation system of claim 4, wherein, The device further comprises: a housing (30) surrounding a portion of the straight tube (2) and the knife switch (1), and And a valve rod (43) that moves the knife switch (1) until a first cutting edge (13) of the knife switch (1) disposed in the housing (30) cuts the straight tube (2) to form the opening (20), and the first cutting edge (13) penetrates along the inner peripheral surface (23).
  6. 6. The truncation system of claim 1, wherein, The device further comprises: a housing (30) surrounding a portion of the straight tube (2) and the knife switch (1), and And a valve rod (43) that moves the knife switch (1) until a first cutting edge (13) of the knife switch (1) disposed in the housing (30) cuts the straight tube (2) to form the opening (20), and the first cutting edge (13) penetrates along the inner peripheral surface (23).
  7. 7. A fluid cutting method for preventing the flow of a fluid in a straight pipe (2) made of a polyolefin material by a flat blade (1), The flat knife switch (1) has a first face (11) and a second face (12) opposite to the first face (11), A semicircular first cutting edge (13) is formed on the distal end side of the knife switch (1), the first cutting edge (13) cuts the straight tube (2) to form a slit-shaped opening (20) extending along the circumferential direction (R) of the straight tube (2) in a slender manner, A sealing part (14) in the shape of an arc band is formed on the proximal end side of the knife switch (1), the sealing part (14) is connected with the cutting surfaces (21, 22) of the straight tube (2) defining the opening (20), The knife switch (1) is provided with a pair of side edge parts (15, 15) connecting the semicircular first cutting edge (13) and the circular arc strip-shaped sealing part (14), Second cutting edges (17) connected to the first cutting edge (13) are formed on the pair of side edge portions (15, 15), respectively, A stopper (16) is mounted on the knife switch (1), the stopper (16) preventing the first cutting edge (13) which invades a half-circumferential portion of the inner circumferential surface (23) from further advancing cutting after the first cutting edge (13) invades the inner circumferential surface (23) of the straight tube (2), The second cutting edge (17) extends to the stop (16), The fluid cutting method includes the following steps: The top (13T) of the first cutting edge (13) is abutted against the outermost peripheral surface (24) of the outermost side of the straight pipe (2); The first cutting edge (13) advances and cuts the straight pipe (2) from the outermost peripheral surface (24) toward a space (27) inside the straight pipe (2); the whole of the semicircular first cutting edge (13) invades into the half-circumference part of the inner circumferential surface (23) of the straight tube (2), After the above step, the semicircular first cutting edge (13) of the knife switch (1) penetrates into the inner peripheral surface (23) of the straight tube (2), and the sealing part (14) is in contact with the cutting surfaces (21, 22) to prevent the flow of the fluid in the straight tube (2).
  8. 8. The method for intercepting a fluid according to claim 7, wherein, A groove obtained by cutting the straight pipe (2) is not formed in advance, and the top (13T) of the first cutting edge (13) is abutted against the outermost peripheral surface (24) of the straight pipe (2).
  9. 9. The method for intercepting a fluid according to claim 8, wherein, After the step of intruding, the step of preventing the first cutting edge (13) from further advancing and cutting after intruding into the half-circumference part of the inner circumferential surface (23) of the straight pipe (2) by abutting the stopper (16) attached to the knife switch (1) against the outermost circumferential surface (24) of the straight pipe (2) is provided.

Description

Shut-off system and fluid shut-off method The application is a divisional application of an application patent application with the application date of 2021, 02, 19, the application number of 202180015073.6 and the name of fluid cutting system and cutting method. Technical Field The present invention relates to a fluid cutting system and a fluid cutting method in which a knife switch (KNIFE GATE) is attached to a straight pipe made of a polyolefin material. Background Conventionally, a process and an apparatus for installing a knife switch in an existing and newly installed Polyethylene (PE) pipe are known (see patent documents 1 and 2). In the inventions disclosed in patent documents 1 and 2, a groove is formed in a straight pipe with a bottom by an end mill in advance, and after the thin skin is formed in the straight pipe, a knife is opened by penetrating a portion of the thin skin, and the knife enters the straight pipe to prevent the flow of fluid. Prior art literature Patent literature Patent document 1 WO 2020/01308 (FIG. 16) Patent document 2 WO2019/167646 (FIG. 16) Disclosure of Invention In each of the prior arts, a groove must be formed in advance. Therefore, not only an end mill, a power tool, or the like for forming the groove is required, but also the number of steps of the construction is large and the construction time is long. In the above-described prior arts, it is necessary to seal two portions, that is, a groove formed by cutting a pipe with an end mill in advance and an opening cut with a knife blade. Therefore, a knife switch to which a rubber seal is attached is required, and the water-stopping structure is liable to become complicated. It is therefore an object of the present invention to provide a fluid shut-off system and shut-off method that can solve these problems. In each of the prior arts, there is no disclosure that the opening is cut with a knife blade without cutting the tube in advance, that is, without forming a thin skin on the tube. On the other hand, the present inventors have proposed using a punching tool to form an elongated opening in a PE tube (JP 2013-199991A). However, in this trial case the slender prismatic punching tool cannot advance to cut the PE tube, and this attempt fails. The reason for this is examined below. In this trial case, when the slender prismatic punching blade cuts into the PE pipe, the PE pipe needs to be retracted by an amount corresponding to the thickness of the blade of the punching blade. However, since the portion of the PE pipe surrounded by the prismatic punching blade is difficult to deform and difficult to compress, it is estimated that the punching blade cannot advance to cut the PE pipe. The cutting system of the present invention comprises a straight pipe 2 made of a polyolefin material, and a flat blade 1 for preventing the flow of fluid in the straight pipe 2, A semicircular first cutting edge 13 is formed on the distal end side of the knife switch 1, the first cutting edge 13 cuts the straight tube 2 to form a slit-shaped opening 20 extending in a slender manner along the circumferential direction R of the straight tube 2, A sealing portion 14 having a circular arc band shape is formed on the proximal end side of the knife switch 1, the sealing portion 14 is connected to cut surfaces 21, 22 of the straight tube 2 defining the opening 20, The knife switch 1 has a pair of side edges 15, 15 connecting the semicircular first cutting edge 13 and the circular arc strip-shaped sealing portion 14, The semicircular first cutting edge 13 of the knife switch 1 and the pair of side edges 15, 15 intrude into the inner peripheral surface 23 along the inner peripheral surface 23 of the straight pipe 2, The knife switch 1 is formed in a flat plate shape having a first surface 11 and a second surface 12 on the opposite side of the first surface 11 between the first cutting edge 13 and the sealing portion 14 and between the pair of side edge portions 15, The slit-shaped openings 20 extend in the straight tube 2 along the circumferential direction R, The seal portion 14 of the knife switch 1 extends from one end 25 to the other end 26 in the circumferential direction R of the opening 20, and is formed in the circular arc strip shape extending from the inner peripheral surface 23 to the outermost peripheral surface 24 of the straight tube 2 in a section from the one end 25 to the other end 26. On the other hand, the cutting method of the present invention is a fluid cutting method for preventing the flow of a fluid in a straight pipe 2 made of a polyolefin material by a flat blade type knife gate 1, The flat blade 1 has a first face 11 and a second face 12 opposite to the first face 11, A semicircular first cutting edge 13 is formed on the distal end side of the knife switch 1, the first cutting edge 13 cuts the straight tube 2 to form a slit-shaped opening 20 extending in a slender manner along the circumferential direction R of the straight t