JPH0554890U - Pipe fitting - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a pipe joint capable of securely tightening a cap nut with a predetermined tightening torque and securely completing the tightening work. [Structure] On the inner diameter side of the male thread, it extends toward the end,
A joint body having a tubular insertion portion formed by providing a cylindrical protrusion that contacts the inner surface of a pipe to be connected, and a lock ring having a tooth portion that bites into the outer peripheral surface of the connected pipe on the inner surface and a slit is formed in the axial direction A screw nut having a taper surface formed on the inner surface of the joint body to press the lock ring against the outer peripheral surface of the connected pipe, and a cap nut having a pipe taper screw on the other side. A pipe joint comprising a polygonal nut having a pipe taper screw that is screwed into the cap nut, wherein the pipe taper screw of the polygonal nut is previously tightened to the pipe taper screw of the cap nut with a constant torque.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a mechanical pipe joint used for connecting, for example, a plastic pipe for water supply and hot water supply.

[0002]

[Prior Art]

 Conventionally, as a pipe joint used for a soft pipe such as a cross-linked polyethylene pipe or a polybutene pipe for supplying water and hot water, there is the one shown in Fig. 3 disclosed in Japanese Utility Model Laid-Open No. 2-56994. In this joint, an insertion portion 7 of the connection pipe 5 is formed at one end of a joint main body 6, and the outer surface of the pipe end 8 of the connection pipe inserted in this portion is inserted through a lock ring 9 having a tooth portion on the inner surface thereof. The cap nut 10 is used to tighten the connection. However, when joining pipes using such pipe joints, generally, after temporarily tightening the cap nuts by hand, the cap nuts should be tightened with a wrench or the like for the purpose of ensuring long-term airtightness. Is done.

[0003]

[Problems to be solved by the device]

 In this case, it is optimal to set the reference torque value in order to obtain the proper tightening amount for the seal, but it is difficult to perform such control at the piping site. Therefore, the difference in the tightening torque occurs due to the difference in the force of the plumbing worker, and it is not possible to obtain a good sealing effect by proper compression of the lock ring and the joint body. In particular, if the tightening is too small, the sealing performance cannot be maintained for a long time. In order to solve such a problem, the present invention provides a pipe joint which can eliminate the variation in the sealing effect due to the difference in the force of the plumbing worker and the difference in the working environment and can complete the tightening work reliably. With the goal.

[0004]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention comprises a joint body having a threaded portion and a nut member having a threaded portion that is screwed into the threaded portion of the body and that pushes the pull-out prevention member toward the connected pipe. In this pipe joint, a taper male screw for pipe is formed on the nut member, and a tightening member having a taper female screw for pipe to be screwed on the nut member is formed, and the taper female screw for pipe of the tightening member is fixed in advance. The pipe joint was tightened with a torque to the taper male screw of the nut member.

More specifically, on the inner diameter side of the male threaded portion, a joint main body having a tube insertion portion formed by providing a cylindrical protrusion extending toward the end and contacting the inner surface of the pipe to be connected, The lock ring has a toothed part that bites into the outer peripheral surface of the pipe to be connected and has a slit formed in the axial direction, and a taper surface formed on the inner surface that is screwed into the male thread of the joint body to form the lock ring. Is pressed against the outer peripheral surface of the pipe to be connected and has a cap nut having a pipe taper screw on the other side and a polygonal nut having a pipe taper screw to be screwed into the cap nut. This is a pipe joint in which the screw has been previously tightened to the taper screw for the cap nut pipe with a constant torque.

[0006]

[Action]

 According to the present invention, as described above, for example, the taper male screw for the pipe of the cap nut and the taper female screw for the pipe of the hexagonal nut are screwed in advance with a predetermined tightening torque and tightened. Keep the minimum tightening torque with the nut. Therefore, if the hexagon nut is tightened with a tool such as a wrench at the time of construction, it will rotate together with the cap nut, and the sealing performance between the joint and the pipe will be secured when the minimum tightening torque required for construction is reached. . Then, when further tightened, the space between the hexagon nut and the cap nut rotates, and the hexagon nut advances. At this time, for example, the marks in the axial direction given to both of them make a difference, and by checking this, it can be confirmed that the cap nut is tightened with a predetermined tightening torque or more. In short, even if the hexagon nut is tightened, the position where the hexagon nut and the cap nut are assembled does not change up to the above-mentioned minimum tightening torque, but if more torque is applied and tightened, the positions of both will shift and the assembly You can check the attachment. This makes it possible to connect the connecting pipe so that the desired sealing performance can always be obtained regardless of the difference in the operator or working environment.

[0007]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a joint showing an embodiment and shows the component structure thereof. In the figure, reference numeral 1 denotes a joint body, which includes a male screw portion 11, a cylindrical protrusion 12 having a plurality of bamboo-saw-shaped circumferential protrusions 16, a male screw portion 14 for connection with other equipment, and a tool. It consists of a hexagonal part 15 to hang. Reference numeral 2 is a lock ring, which is composed of a tooth portion 21 on the inner peripheral surface that bites into the outer peripheral surface of the end portion of the connecting pipe, a slit 22 that extends in the axial direction, and a tapered surface 23 formed on the outer peripheral surface at one end. A cap nut 3 is composed of a female thread portion (not shown) that is screwed into the male thread portion 11 of the joint body, and a pipe taper male thread 31. Reference numeral 4 denotes a hexagonal nut, which is composed of a taper female thread 41 for a pipe to be screwed into a taper male thread 31 for a pipe of a cap nut, and a hexagonal portion 42 for hanging a tool.

FIG. 2 shows a state in which the joint and the connecting pipe are connected, and the upper half shows a sectional view and the lower half shows an external view. Explaining the temporary assembly of this joint, the hexagon nut 4 is tightened to the cap nut 3 to the minimum tightening torque required for assembling the cap nut 3 and the joint body 1. Then, printing ink or marking marks 33 and 43 are provided on the same line in the axial direction of the surfaces of the hexagon nut 4 and the cap nut 5. For connection work, insert the connecting pipe 5 into the joint body 1, attach the lock ring 2 so that the inner surface of the cap nut 3 presses the outer peripheral surface of the connecting pipe 5, and tighten the cap nut 3 to the joint body 1 by hand tightening. Put in. Then, the hexagon nut 4 previously screwed to the cap nut 3 is tightened using a tool such as a spanner. The hexagon nut 4 rotates together with the cap nut 3 up to the pre-tightened minimum tightening torque, but when the torque is reached, the hexagon nut 4 starts rotating from the cap nut 3 and moves forward to be displaced. Then, after confirming that the marks are different from each other, tightening is completed.

Further, as another means for confirming that the positions of the hexagon nut and the cap nut are misaligned, a red or blue colored or colored member is fitted on the front end surface of the pipe nut taper male screw of the cap nut, You can use the fact that this color is hidden due to the displacement due to the forward movement of the hexagon nut. Alternatively, the hexagonal nut 4 may always be brought into contact with the end face of the cap nut 3 on the hexagonal nut side, thereby confirming the completion of tightening.

FIG. 3 shows another embodiment, showing a state in which a joint and a connecting pipe are connected, the upper half shows a sectional view, and the lower half shows an external view. The difference from the above embodiment is that the cap nut 30 is formed with a taper female thread for a pipe, and the hexagonal nut 40 is formed with a taper male thread for a pipe, and both are screwed and tightened in advance with a constant torque. Therefore, this embodiment also has the same actions and effects as the above, and the same modified example as the above can be implemented for the confirmation of the positional deviation.

[0011]

[Effect of the device]

 As described above, the joint of the present invention is a pipe joint that can tighten the cap nut with a predetermined tightening torque, is easy to identify, and does not leak or come out after connection.

[Brief description of drawings]

FIG. 1 is a perspective view of a joint showing an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view showing a state in which the joint of FIG. 1 and a connecting pipe are connected.

FIG. 3 is a partial cross-sectional view showing a state in which a joint and a connecting pipe are connected in another embodiment of the present invention.

FIG. 4 is a sectional view of a joint showing a conventional example.

[Explanation of symbols]

 1 ... Fitting body 2 ... Lock ring 3 ... Cap nut 4 ... Hexagon nut 5 ... Connection pipe

Claims (2)

[Scope of utility model registration request] 1. A pipe joint comprising: a joint body having a threaded portion; and a nut member having a threaded portion that is screwed into the threaded portion of the body and pressing the pull-out preventing member toward the connected pipe side. A pipe taper screw is formed on the member, and a fastening member having a pipe taper screw formed on the nut member is formed,
A pipe joint, wherein the pipe taper screw of the tightening member is previously fastened to the pipe taper screw of the nut member with a constant torque. 2. A joint main body in which a tubular insertion portion is formed by providing a cylindrical projection portion, which extends toward the end portion and contacts the inner surface of the pipe to be connected, on the inner diameter side of the male screw portion, and the pipe to be connected. The lock ring has a tooth portion that bites into the outer peripheral surface on the inner surface and is formed with a slit in the axial direction, and the lock ring is screwed into the male thread portion of the joint body, and the lock ring is formed by the tapered surface formed on the inner surface. Of a polygonal nut having a pipe taper screw that is pressed against the outer peripheral surface of the polygonal pipe and has a pipe taper screw on the other side, and a pipe taper screw that is screwed into the cap nut. A pipe joint characterized in that it is fastened to the pipe taper screw of the cap nut.