JP5473584B2 - Pressure relief fitting - Google Patents

Description

  The present invention relates to a pressure relief joint, and more particularly to a pressure relief joint used for releasing pressure in a pipe (hose) equipped with a self-seal coupling.

  Self-seal couplings are installed at places where pipes for supplying various fluids need to be attached / detached so that the pipes can be attached / detached easily. The self-sealing coupling is formed so as to open when the pipe is connected to allow fluid to flow, and close when the pipe is removed to prevent fluid leakage. After removing a pipe fitted with such a self-sealing coupling, when connecting the pipe next time, the fluid in the pipe expands due to the temperature rise, and the pressure in the pipe increases due to the increase in the volume of the fluid. Then, the normal seal cannot open the self-seal coupling, and the self-seal coupling cannot be coupled. For this reason, an oil reservoir is integrally provided in the self-sealing coupling (for example, refer to Patent Document 1), or the pressure in the pipe is released to the tank side via a pressure relief valve or a pressure relief hose (for example, (See Patent Document 2), or by providing a detachable depressurization device that absorbs the pressure in the pipe (see, for example, Patent Document 3), the pipe is depressurized to reduce the fluid pressure in the pipe. The pipes can be connected.

Japanese Utility Model Publication No. 4-68300 JP 2006-233571 A JP 2007-303551 A

  However, in the above-mentioned Patent Document 1 and Patent Document 2, there is a problem that the joint is enlarged because an oil sump or a pressure relief valve protrudes from the side of the joint. In Patent Document 2 and Patent Document 3, In addition, the hose and the pressure release device must be attached and detached during the pressure release, which not only complicates the work, but also may cause fluid to leak out of the pipe during the attachment / detachment. Further, if there are protrusions on the side of the joint, there is a risk that the joint will be damaged by getting in the way during pipe handling or being caught by something.

  Accordingly, the present invention can reduce the pressure in a pipe for mounting a self-sealing coupling, in particular, a liquid-fluid pipe such as a hydraulic pipe with a simple operation, and can be easily manufactured with a simple structure. It aims to provide a joint.

In order to achieve the above object, the pressure release joint of the present invention is a pressure release joint for reducing pressure in a pipe provided in a pipe equipped with a self-seal coupling. A base-side pipe connecting member fixed to one end side opening of the main body and a cylindrical decompression member provided in the other end side opening of the joint main body, and the joint main body is formed on the inner surface of the one end side opening part. A large-diameter female screw portion, a small-diameter female screw portion formed on the inner surface of the opening on the other end side, and an inner surface of a joint body between the large-diameter female screw portion and the small-diameter female screw portion. A cylindrical sealing surface having a circular cross section formed to have a larger diameter than the female screw portion, and the base side pipe connecting member has a base side pipe connecting female screw portion formed on the inner surface and the joint body on the outer surface Large-diameter male threaded into the large-diameter female thread And a large-diameter flange portion projecting from one end side opening of the joint main body, which is connected to the joint main body outside of the large-diameter male screw portion, and the decompression member has an internal thread portion for connecting the tip end side pipe on the inner surface And a small-diameter male screw portion that is screwed into the small-diameter female screw portion of the joint body, and an external surface of the small-diameter male screw portion that is connected to the outside of the joint body and protrudes from the other end side opening of the joint body. A small-diameter cylindrical projecting portion, and a retaining flange portion that is connected to the inside of the joint body of the small-diameter male screw portion and has a larger diameter than the small-diameter male screw portion and is disposed in the cylindrical sealing surface of the joint body. The pressure reducing member is provided so as to be movable in the axial direction of the joint body by relative rotation of the small-diameter male screw portion and the small-diameter female screw portion.

  According to the pressure release joint of the present invention, the internal space volume of the joint main body can be expanded by moving the pressure reducing member provided in the joint main body to the other end side of the joint main body. The pressure in the pipe can be increased and decreased. In addition, since the structure for depressurization is arranged in the axial direction of the pipe, it is possible to avoid an increase in size of the joint and to prevent the joint from becoming an obstacle when handling the pipe and to keep the manufacturing cost low. Can do. Further, since it is not necessary to attach / detach the pressure release means to / from the pipes and joints, the pressure release work can be easily performed, and the fluid in the pipe does not leak to the outside during the pressure release work. Moreover, it can prevent that a decompression member falls out from a coupling main body by setting it as the structure which can move a decompression member in a predetermined range. Therefore, by using the pressure relief joint of the present invention for the hydraulic piping of construction machines such as large cranes and pile driving machines that are disassembled and transported and assembled at the work site, the hydraulic piping is connected efficiently and in a short time. This prevents the hydraulic oil from leaking and contaminating the surroundings.

It is sectional drawing of the pressure relief joint which shows one example of this invention. Similarly, it is sectional drawing of the pressure relief joint at the time of hydraulic piping connection. It is an exploded perspective view of a pressure relief joint similarly.

  The pressure relief joint 11 shown in the present embodiment is mounted between a pipe 12a and a self-sealing coupling 12b in a pipe (hose) 12 to which a self-sealing coupling is attached, and is one end connecting the pipe 12a. A structure in which a base side pipe connecting member 13 on the (base end) side and a decompression member 14 on the other end (tip side) connecting the base part of the self-seal coupling 12b are respectively attached to both end openings of the joint body 15. Have.

  The joint body 15 has a cylindrical shape with a hexagonal cross section on the outer surface and a circular cross section on the inner surface. The joint main body 15 has a large inner surface formed on the inner surface of the proximal end side opening. A diameter female thread portion 15a and a small diameter female thread portion 15b formed on the inner surface of the distal end side opening are provided. The small-diameter female screw portion 15b is formed to have a smaller diameter than the inner diameter of the large-diameter female screw portion 15a, and the joint inner surface between the large-diameter female screw portion 15a and the small-diameter female screw portion 15b has a smaller diameter than the large-diameter female screw portion 15a. A cylindrical sealing surface 15c having a diameter larger than that of the small diameter female thread portion 15b is formed. A retaining step portion 15d is formed at a portion between the distal end of the cylindrical sealing surface 15c and the proximal end of the small diameter female screw portion 15b.

  The base-side pipe connecting member 13 has a base-side pipe connecting female screw part 13a for connecting the pipe 12a on the inner surface, and a large-diameter male screw part screwed into the large-diameter female screw part 15a on the outer surface. 13b is formed. Further, a large-diameter flange portion 13c is continuously provided on the outside of the joint body of the large-diameter male screw portion 13b. The large-diameter male screw portion 13b is disposed in the cylindrical seal surface 15c on the distal end side, and has a seal ring on the outer surface. A cylindrical portion 13e in which an annular seal groove 13d for mounting 16 is formed is provided. Further, a tool engagement surface 13f that is chamfered is formed on the outer surface of the large-diameter flange portion 13c.

  The decompression member 14 is formed with a distal-end-side pipe connection female thread portion 14a for connecting the self-seal coupling 12b on the inner surface, and a small-diameter male thread portion 14b that is screwed to the small-diameter female thread portion 15b on the outer surface. Is formed. A retaining flange portion 14d is provided in the tubular seal surface 15c on the inside of the joint body of the small diameter male thread portion 14b via the small diameter tubular portion 14c. The retaining flange portion 14d has an outer diameter that is larger than the outer diameter of the small-diameter male screw portion 14b and slightly smaller than the inner diameter of the cylindrical seal surface 15c, and for mounting the seal ring 17 on the outer surface. An annular seal groove 14e is provided. A small-diameter cylindrical projection 14f having an outer diameter smaller than the outer diameter of the small-diameter male screw portion 14b is provided on the outer side of the joint body of the small-diameter male screw portion 14b. A chamfered tool engaging surface 14g is formed.

  In this pressure relief joint 11, first, the pressure reducing member 14 with the seal ring 17 attached to the annular seal groove 14e is inserted from the proximal end side opening of the joint body 15 with the small-diameter cylindrical protrusion 14f facing the distal end side. Then, after the small-diameter male screw portion 14b is screwed into the small-diameter female screw portion 15b of the joint body 15 and the small-diameter cylindrical projection portion 14f is projected from the distal end side opening of the joint body 15, the base end side of the joint body 15 From the opening, the base side pipe connecting member 13 with the seal ring 16 mounted in the seal groove 13d is inserted, and the large-diameter male screw portion 13b is screwed into the large-diameter female screw portion 15a of the joint body 15 and tightened, and the large-diameter flange It is formed by fixing the base side pipe connecting member 13 to the joint main body 15 in a state where the portion 13 c is projected from the base end side opening of the joint main body 15.

  By assembling the base side pipe connecting member 13 and the pressure reducing member 14 to the joint body 15 in this way, the seal ring 16 of the base side pipe connecting member 13 and the seal ring 17 of the pressure reducing member 14 are connected to the cylindrical sealing surface of the joint main body 15. It comes into contact with the inner surface of 15c and enters a liquid-tight state. The base side pipe connecting member 13 is fixed to the joint main body 15, while the decompression member 14 is rotatable in a state where the small diameter male screw portion 14b and the small diameter female screw portion 15b are screwed together. When the pressure reducing member 14 is turned in the tightening direction or the loosening direction with respect to the main body 15, the pressure reducing member 14 can be moved in the axial direction of the joint main body 15 while maintaining a liquid-tight state by the seal ring 17. ing.

  As shown in FIG. 1, the movement range of the decompression member 14 with respect to the joint body 15 is such that the proximal end surface of the retaining flange portion 14d abuts the distal end surface of the base side pipe connection member 13, and the decompression member 14 is the most proximal. 2 and the position where the small-diameter cylindrical projecting portion 14f projects from the opening on the distal end side of the joint body 15, and as shown in FIG. 2, the end surface on the distal end side of the retaining flange portion 14d contacts the retaining step portion 15d. In contact with each other, more than half of the small-diameter male screw portion 14b protrudes from the opening on the distal end side of the joint body 15, and is regulated within a range from the position where the decompression member 14 moves to the most distal end side.

  The pressure release joint 11 formed in this way normally connects one end of the pipe 12a to the female pipe part 13a for the base side pipe connection of the base side pipe connection member 13 and at the same time, the female thread for the tip side pipe connection of the decompression member 14 It is used in a state where the base of the self-seal coupling 12b is connected to the part 14a. When the fluid flows, as shown in FIG. 1, the decompression member 14 is used in a state of being moved to the proximal end side of the joint body 15, and when the pressure in the pipe is released and the pipe is disconnected, the decompression member 14 is shown in FIG. After confirming that the state shown in FIG. 1 is satisfied, the self-seal coupling 12b is disconnected to separate each pipe.

  When the separated pipe is reconnected, the fluid volume expands due to a rise in the temperature of the fluid sealed in the pipe 12 whose both ends are closed by self-sealing couplings, and the pressure in the pipe 12 rises. When the self-seal coupling 12b cannot be coupled with the coupling operation force of the tool, a tool such as a spanner is engaged with the outer surface of the joint body 15 and the tool engagement surface 14g protruding from the opening on the tip side of the joint body 15. The decompression member 14 is rotated in the loosening direction with respect to the joint body 15, and the decompression member 14 is projected from the distal end side of the joint body 15.

  Thereby, the space between the distal end side end surface of the base side pipe connecting member 13 and the proximal end side end surface of the retaining flange portion 14d is expanded, and a space E1 is formed in the cylindrical seal surface 15c, so that the internal space of the joint main body 15 can be formed. By expanding the volume, the volume in the pipe 12 closed at both ends is increased by the volume of the space E1, and the fluid pressure in the pipe 12 can be reduced, so that the self-seal coupling 12b can be coupled. It can be in a state.

  As described above, when the pressure in the pipe 12 whose pressure has been increased is to be released, the pressure reducing member 14 need only be rotated with respect to the joint body 15, so that the pressure in the pipe 12 can be released with a simple operation. It can be carried out. In addition, since the structure for depressurization is arranged in the axial direction of the pipe 12 and does not protrude sideways as in the prior art, it is possible to avoid an increase in size of the joint and to prevent the joint from being disturbed when handling the pipe. It will never be. Furthermore, since the metal tube can be manufactured only by processing, the manufacturing cost can be kept low. Further, since it is not necessary to attach / detach the pressure release means to / from the pipes and joints, not only the pressure release operation is facilitated, but also the fluid in the pipe does not leak to the outside during the pressure release operation. Further, as shown in the embodiment, by providing a retaining step portion 15d with which the retaining flange portion 14b of the decompression member 14 abuts on the inner periphery of the joint body 15, the decompression member 14 is connected to the joint during the decompression operation. It can be reliably prevented from falling off the main body 15.

  Further, the volume of the space E1 can be set according to the volume of the pipe 12 to be used. For example, in the case of a 1 inch hose with an inner diameter of 25.4 mm used for a hydraulic working machine and a hose length of 10 m, the expansion amount (volume increase amount) of hydraulic oil when the temperature rises by 10 ° C. is 0.037. Since the inner diameter of the joint body 15 is set to 52 mm and the sliding amount of the decompression member 14 is set to 25 mm, the volume of the space E1 can be secured at 0.050 liters or more. Even if the temperature when the pipe is connected rises by about 15 ° C., the pressure in the pipe can be surely released.

  The pressure release joint of the present invention is most suitable for hydraulic piping of construction machinery having a large number of hydraulic piping, such as large cranes and pile driving machines that are disassembled during transportation and assembled according to work conditions. It can also be applied to. Further, the pipe and the self seal coupling may be connected in reverse, and the pipe or the self seal coupling may be directly connected to the base side of the joint body without providing the base side pipe connection member. Furthermore, the decompression member may be formed to be linearly slidable with respect to the joint body, and a regulating member that regulates the sliding state may be separately provided.

  DESCRIPTION OF SYMBOLS 11 ... Pressure release joint, 12, 12a ... Pipe, 12b ... Self-seal coupling, 13 ... Base side pipe connection member, 13a ... Base side pipe connection internal thread part, 13b ... Large diameter male thread part, 13c ... Large diameter flange part , 13d ... annular seal groove, 13e ... cylindrical part, 13f ... tool engaging surface, 14 ... pressure reducing member, 14a ... female thread part for tip side pipe connection, 14b ... small diameter male thread part, 14c ... small diameter cylindrical part, 14d ... Stop flange part, 14e ... annular seal groove, 14f ... small diameter cylindrical protrusion, 14g ... tool engagement surface, 15 ... joint body, 15a ... large diameter female thread part, 15b ... small diameter female thread part, 15c ... cylindrical seal surface , 15d: retaining step, 16, 17 ... seal ring, E1 ... space

Claims (1)

In a pressure relief joint for reducing pressure in a pipe provided in a pipe equipped with a self-seal coupling, a tubular joint body, and a base side pipe connection member fixed to one end side opening of the joint body, A cylindrical decompression member provided in the other end side opening of the joint body, and the joint body is formed on the inner surface of the one end side opening part and on the inner surface of the other end side opening part And a cylindrical seal having a circular cross section formed on the inner surface of the joint body between the large-diameter female screw portion and the small-diameter female screw portion and having a smaller diameter than the large-diameter female screw portion and a larger diameter than the small-diameter female screw portion. A base-side pipe connection female screw part is formed on the inner surface, and the outer surface has a large-diameter male screw part screwed into the large-diameter female screw part of the joint body, The large-diameter male screw part is connected to the outside of the joint body. A large-diameter flange portion projecting from one end side opening of the joint body, and the decompression member has a female thread portion for connecting a distal end side pipe formed on the inner surface and a small-diameter female thread portion of the joint body on the outer surface. A small-diameter male thread portion that is screwed into the joint body, a small-diameter cylindrical projecting portion that is connected to the joint body outside of the small-diameter male thread portion and projects from the other end side opening of the joint body, and the joint body inner side of the small-diameter male thread portion And a retaining flange portion having a diameter larger than that of the small-diameter male screw portion and disposed in the cylindrical sealing surface of the joint body, and the pressure reducing member includes a small-diameter male screw portion and a small-diameter female screw portion. A pressure relief joint, which is provided so as to be movable in the axial direction of the joint body by relative rotation.

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