JPH0512555Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a branch pipe joint used when connecting a branch pipe to a main pipe.

Prior Art In recent years, pipes made of thermoplastic resin have been used for water pipes, drainage pipes, gas pipes, etc. These pipes can be melt-bonded and have the advantage of being easier to perforate than metal pipes, so when connecting branch pipes, use a branch pipe joint 1 as shown in Figure 3. After applying it to main pipe 2 and melting and adhering it, a hole is drilled into the main pipe through the branch pipe, and then branch pipe 3 is attached and connected, but during the work, fluid inside the main pipe leaks after drilling. It was necessary to either leave the main pipe empty or seal the main pipes before and after the joint joint to prevent this.

As shown in FIG. 4, there has also been proposed a device in which a connecting portion 4 to a branch pipe is provided on the side. According to this joint, after connecting the branch pipe 3, the main pipe 2 can be bored by the cutter 5, which is screwed in from above, and since the hole is blocked by the cutter, the main pipe can be emptied. Although it is no longer necessary to seal the main pipe before and after the joint, it becomes necessary to newly seal the upper end of the joint to prevent the fluid in the main pipe from leaking after drilling. For this reason, an attempt has been made to seal the cutter by pulling up the cutter used to make the hole and fixing it on the upper end of the joint, but the sealing performance is not sufficient, so a cap 6 is placed on top of it as shown in the figure, and the cap 6 is screwed in. o between the upper end surface of the joint and
It has also been proposed to seal by a ring 7.

Problems to be solved by the invention As mentioned above, when closing the upper end of the joint with the cutter used for drilling into the main pipe and sealing it,
Not only is the sealing performance insufficient, but providing a cutter for each joint is uneconomical and increases costs.

Therefore, the present invention attempts to fit a plug into the upper end of the joint instead of the cutter and seal it with this, but one of the problems in this case is that after the cutter has pierced the main pipe, it is difficult to connect the cutter to the joint. The issue is how to maintain the sealing performance from when the plug is pulled out until the plug is inserted. This is a particular problem when the fluid is a toxic or flammable gas that could be dangerous if it leaks.In order to prevent gas leaks, it is necessary to vent the gas and empty the main pipe as in the past, or to remove the gas at the joint joint. Sealing the front and rear main pipes takes a long time and is labor intensive.

Another problem is that when a plug is inserted into the upper end of the joint to seal it, even though the sealing performance is initially maintained, in the case of joints made of thermoplastic resin that can be heat-sealed, internal pressure may cause the seal to deteriorate over a long period of time. As a result, creep occurs and the inner diameter of the plug fitting portion gradually increases, resulting in a loss of sealing performance.

The present invention has been made with the aim of solving the above problems.

Solution to the Problem In order to solve the above-mentioned problem, the present invention uses a working pipe equipped with a valve that can open and close the pipe, connects it to the upper end of the joint, and uses a cutter and a plug to open and close the pipe. In order to solve the latter problem, a cap with an O-ring inside is used and screwed onto the upper end of the joint, and the O-ring is attached to the joint. It is designed to be joined to the upper end.

That is, in the present invention, a working pipe is removably connected to one end thereof and has a valve that opens and closes the pipe.
and a main body through which the cutter can move forward and backward, a saddle part provided at the other end of the main body and melt-bonded to the main pipe, a connecting part protruding from the side of the main body to which a branch pipe is attached, and a working pipe. After the connection, the pipe is opened by operating the valve, and the working pipe is inserted into one end of the main body.The plug has a sealing plug with a first O-ring fitted on the outside, and a second O-ring inside. The second O-ring is characterized in that it consists of a cap that is joined to one end of the main body when screwed onto the main body.

Function: Connect the working pipe to one end of the main body, open the working pipe passage with the valve, and insert the cutter through the cutter and into the main body. Then, make a hole in the main pipe. After drilling, the cutter is pulled out and when it is retracted past the valve, the working pipe is closed off by operating the valve.
This maintains the seal even when the cutter is pulled out. Next, insert the plug into the working pipe, open the conduit of the working pipe by operating the valve, push the plug in, and fit it into one end of the main body to seal it. After sealing, the working tube is removed, then the cap is screwed on and further sealed. Even if the sealing performance of the plug is impaired due to creep due to long-term use, or if the dimensional accuracy of the fitting part is poor and sufficient sealing performance cannot be obtained, the cap will Sealing performance is maintained.

Embodiment The branch pipe joint shown in FIG.
A saddle part 14 having a concentric hole 13 communicating with the main body, a connecting part 16 projecting laterally from the main body and having a horizontal hole 15 communicating with the shaft hole 11, and a connecting part 16 fitted into the upper end of the shaft hole of the main body. , a plug 18 having one or more O-rings 17 fitted around its outer periphery, and a cap 21 that is placed over the upper end of the main body and is screwed on, and that has an O-ring 20 inside that is joined to the upper end surface of the main body. There is.

This joint is constructed as described above, and when connecting a branch pipe to the main pipe, it is done as follows.

First, the saddle portion 14 is fitted onto the main pipe 23 and bonded by melting. Before and after this, the branch pipe 24 connects to the connecting part 16.
A working pipe 26 is connected to the upper end of the main body, and is provided with a pot 25 that is attached to and connected to the pipe on which the cutter advances and retreats, and which opens and closes the pipe. Next, the cutter 27 passed through the working pipe is advanced to the main body 12, and while being rotated while protruding from the hole 13, the main pipe 23 is bored. After drilling, the cutter 27 is attached to the main body 12.
Subsequently, it retreats inside the working pipe 26, and when it retreats beyond the pot 25, the conduit is blocked by the pot and then removed. Next, the plug 18 with the O-ring 17 fitted thereon is inserted into the working tube 26, and pushed into the upper end of the main body 12 through the working tube 26, which has been unoccluded by the plug. Thereafter, the cap 21 is screwed onto the upper end of the main body.

Effects of the invention As described above, the present invention uses a working pipe that has a valve that can open and close the pipeline and that can be detachably connected to the joint, and further fits into the joint body through the working pipe. By operating the valve using a plug that can seal, the seal can be maintained after drilling with the cutter until the cutter is pulled out and the plug is closed. In order to prevent fluid leakage during the time between the main pipe and the plug, there is no need to empty the main pipe or seal the main pipe before and after the joint is connected, making sealing relatively easy.

According to the present invention, after the plug is fitted and sealed, a cap with an O-ring is used to cover the upper end of the joint and screwed, and the O-ring is joined to the upper end of the joint, thereby preventing creep. Even if the diameter at the plug fitting part gradually expands and the sealing performance of the plug is impaired, dimensional accuracy at the fitting part of the fitting due to injection molding is poor and the sealing performance is deteriorated. Even if there is a situation where sufficient sealing performance cannot be obtained, the sealing performance can still be maintained, and the sealing performance can be maintained reliably and for a long period of time.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a branch pipe joint according to the present invention, FIG. 2 is a sectional view showing a state during connection work, and FIGS. 3 and 4 are sectional views of a conventional example. 1... Shaft hole, 12... Main body, 14... Saddle part, 16... Connection part, 17... O-ring, 18...
...Plug, 20...O-ring, 21...Cap, 23...Main pipe, 24...Branch pipe.

Claims (1)

[Scope of utility model registration request] A working pipe 26 equipped with a valve 25 for opening and closing the pipe is removably connected at one end, and a cutter 27 is inserted into the main body 12 so as to be able to move forward and backward. A saddle part 14 to be bonded, a connecting part 16 that protrudes to the side of the main body and to which a branch pipe 24 is attached, and a sealing part that is fitted to one end of the main body through the working pipe 26 and has a first O-ring 17 fitted on the outside. plug 18 and a second O-ring 20 inside
A branch pipe joint comprising: a cap 21 which connects the second O-ring 20 to one end surface of the main body when the second O-ring 20 is screwed over one end of the main body.