JPS6227985B2 - - Google Patents

Abstract

PURPOSE:To enable a holding of a predetermined pressing force for a required period of time without requiring any manual operation by a method wherein a torque wrench is arranged in a clamp for holding a plastic pipe. CONSTITUTION:The clamp 2 for holding the plastic pipe is fixed on a base block 1, the plastic pipe to be melted or a clamp 3 for holding a plastic saddle is slidably arranged on the axis 10. Lower end of the torque wrench 11 is connected to a link 12 keyed to the axis arranged in the clamp 2 and pivotally attached to the base block 1 by a link 13. In order to fix the torque wrench 11 at a position for applying a desired pressing force, a torque wrench holder 14 is arranged. The holder 14 is comprised of a cylinder unit 16 pivotally fixed to a bracket 15 arranged in the base block 1, an axis 18 pivotally attached to a bracket 17 of the torque wrench 11 and slid therein, and a set screw 19 for fixing the axis 18 to the cylinder 16.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention heats and melts the fused surfaces of plastic tubes to be joined together, presses the tubes together at a prescribed pressure for a prescribed period of time, cools them together, This invention relates to a plastic pipe fusion machine that fuses and joins pipes together.

[Prior art] Metal pipes have traditionally been used as city gas pipes, but medium-density polyethylene pipes have appropriate rigidity and flexibility as city gas pipes, and are not susceptible to underground corrosion like metal pipes. It has the excellent property of being able to be used semi-permanently without any problems.

Fusion bonding is used to join polyethylene pipes.
For this reason, various types of fusion splicers are being researched and developed. To join polyethylene pipes using such a fusion splicer, the fusion surface (joining surface) is chamfered, the heater fusion surface is heated and melted, and the tubes to be joined are held at a predetermined pressure for a predetermined period of time. The method is to press them together and wait for them to cool and integrate. In this case, in conventional fusing machines, the pressing force is manually maintained for a predetermined period of time while waiting for cooling and integration. For this reason, the operator needs experience; if the pressing force is too large, the ends of the tubes will be crushed, and if the pressing force is too small, the tubes will not be joined together sufficiently. Therefore, it has been extremely difficult to maintain a constant pressing force.

[Object of the Invention] Therefore, an object of the present invention is to provide a plastic pipe fusion machine that can easily maintain a constant pressure force between the pipes without requiring any experience.

[Structure of the Invention] According to the present invention, the fused surfaces of plastic tubes to be joined to each other are heated and melted, the tubes are crimped together at a prescribed pressure for a prescribed time, and the tubes are bonded together after cooling and integrating. A fusion splicer that performs fusion splicing is provided with a second clamp that clamps the tube and can move toward the first clamp that is placed in an immovable state while clamping the tube. is provided with a torque wrench that moves and presses the first clamp placed in an immovable state that clamps the pipe, and the torque wrench includes a torque wrench holder that fixes the clamp at a position with a predetermined pressing force. The clamps consist of a pair of split rings, one fixed and the other pivotally mounted, having a liner that grips the tube and a fixed split ring. The ring is provided with a clamp stopper that limits the distance the clamp can travel.

[Operations and Effects of the Invention] Therefore, first, two plastic tubes are held between first and second clamps, respectively. At that time, the liner is replaced as appropriate depending on the difference in tube diameter. The joint surfaces are then chamfered to a flat surface in a known manner and heated using a heater, also in a known manner. All of the above belong to known techniques.

Once the joint surfaces of the tubes have been heated and melted in this way, use a torque wrench to attach the second clamp to the first clamp.
towards the clamp. Then, the movement distance of the second clamp is limited by the clamp stopper, so the torque wrench is fixed there with a torque wrench holder. After the predetermined cooling time has passed and both tubes are joined, open the torque wrench holder and return the torque wrench to the first and second tubes.
Just remove the clamp.

As described above, according to the present invention, the movement distance is limited in advance by the clamp stopper to apply a predetermined pressing force, and the torque wrench is held by the torque wrench holder, so that the torque wrench is held by the torque wrench holder. The joint surfaces can be pressed together for a period of time during which the worker can do other work, which is extremely efficient and has good workability. Moreover, the worker does not need to knead the product, and can always press it with constant pressure. Therefore, there is no variation in the strength of the bonding surfaces, and no leakage occurs.

[Preferred Embodiment] When carrying out the present invention, it is preferable that a rotary cutter housed in a cutter case be used as a cutter for chamfering the joint surface of a pipe, and the cutter case is rotatably attached. In this way, after the chamfering operation is completed, the cutter case can be rotated and the heater can be positioned on the chamfered joint surface to heat the joint surface. The heater may be configured to be detachably attached to one of the clamps.

[Examples] Examples of the present invention will be described below with reference to the drawings.
Figures 1 and 2 show the case of fusion joining polyethylene pipes as city gas conduits. In the figures, 2 is a clamp that holds the end of one pipe to be joined, and 3 is a clamp that holds the end of the other pipe. The clamps 2 and 3 are composed of split rings 4a and 4b as shown in FIG. 2. Split ring 4
One of a and 4b is fixed and the other is linked to it 5
These split rings 4
a, 4b have a liner L1 with a semicircular cross section inside;
L2 and split ring 4 as shown in FIG.
When a, 4b are tightened, the liners L1, L2 have an inner diameter that is the same as the diameter of the end of the tube to be gripped. Liner L of split rings 4a and 4b
1, the end of the tube is held between L2 and the male thread 7 of the pressing screw consisting of the female threaded pipe 6 and the male thread with handle 7 is screwed into the female threaded pipe 6 to press and hold the end of the pipe. The ends of the tubes are then straightened. code 8
is a heater holder for a heater (not shown) for heating a plastic tube.

One of the clamps 2 is stationary, and a slide bearing 9 is provided below the other clamp 3, which slides along the axes 10, 10 toward the stationary clamp 2. do. A torque wrench 11 is provided for moving and pressing the clamp 3 toward the immovable clamp 2, and the lower end of the torque wrench 11 is connected to a link 12 keyed to a shaft provided on the clamp 3. , then the link 13 connects the base 1
It is pivoted to. Therefore, torque wrench 11
By operating the clamp 3, the shafts 10, 10
Slide it toward clamp 2 along. The torque wrench 11 normally applies a pressing force of 0.1 to 900 kg·cm.

A torque wrench holder, generally designated 14, is provided for fixing the torque wrench 11 at a predetermined pressing force position. The torque wrench holder 14 has a cylindrical body 1 pivotally mounted on a bracket 15 provided on the base 1.
6 and a shaft 18 which is pivotally connected to a bracket 17 provided on the torque wrench 11 and slides inside the cylinder body 16.
and a set screw 19 for fixing the shaft 18 to the cylindrical body 16.

In addition, 20 is a cutter case which is provided with a slide bearing 21 below and accommodates a chamfering cutter which moves along the shafts 10, 10.

This cutter case 20 is pivotally mounted at a pin 21, and is provided with a motor (not shown) and a rotating cutter 22 therein, so that a blade 23 performs a chamfering operation. Therefore, during chamfering work, if the rotary cutter 22 is inserted between the clamps 2 and 3 by pivoting at the pin 21, the clamped pipe can be chamfered and the end face of the pipe can be properly perpendicular to its axis. can do.

Furthermore, the fixed split ring 4b is provided with clamp stoppers 30, 30 so as to be able to adjust its protruding length, so as to limit the length between the cutter case 20 and the clamps 2, 3 during chamfering work.

Next, a procedure for fusion-bonding polyethylene pipes using the above-mentioned fusion splicer will be explained. The male screws 7 of the clamps 2 and 3 are loosened to insert the ends of the tube into the split rings 4a and 4b, and then the male screws 7 are tightened to hold the tube between the clamps 2 and 3. At this time, by appropriately exchanging the liners L1 and L2 according to the difference in diameter of the tube to be gripped, the tube can be correctly positioned and gripped. Then, the cutter 22 chamfers the fused surface (joint surface) of the pipe, and then the cutter case 20 containing the cutter is pivoted at the pin 21 (see Fig. 2), and the clamp 2 and clamp 3 are moved. Create a space between the opposing joint surfaces of the tubes fixed with. Next, a plate-shaped heater (not shown) is placed in this space, and the arms protruding on both sides of the upper side of the heater are connected to the heater receivers 8 and 8 provided at the top of clamp 2 and clamp 3, respectively. (In Figure 1, each heater holder 8, 8 is hidden by the male screw 7, 7 and is no longer visible.) Also, the two arms protruding from both sides of the heater The elongated hole allows for axial movement independent of the movement of the clamp. By moving the clamp 3 closer to the clamp 2 using a torque wrench, the joint surfaces of the opposing tubes are pressed against both sides of a plate-shaped heater (not shown). This heats and melts the joint surfaces. Then a heater (not shown)
is removed, and then the torque wrench 11 is operated with the setscrew 19 of the torque wrench holder 14 loosened, and the clamp 3 is moved and pressed toward the immovable clamp 2 side. Then, the set screw 19 of the torque wrench holder 14 is tightened to maintain a predetermined pressing force for a predetermined period of time, thereby fixing the shaft 18 to the cylindrical body 16 and fixing the torque wrench 11 at the position of the predetermined pressing force.
When the molten part has cooled and the tubes are completely joined together, the setscrew 19 of the torque wrench holder 14 is loosened and the clamp 3 is moved back. In this way, the joining work is completed.

In the above description, a polyethylene pipe for a gas pipe has been described, but it is clear that the present invention can also be carried out using plastic pipes other than polyethylene pipes to fusion-bond pipes for other purposes, such as water pipes.

[Summary] As explained above, according to the present invention, a predetermined pressing force can be maintained for a necessary period of time without requiring manual labor, and pipes can be fused together efficiently and reliably.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, and FIG. 1 is a side view, partially in cross section, of a fusing machine embodying the present invention, and FIG. 2 is a front view thereof. 1...Base, 2...Fixed side clamp, 3...Movable side clamp, 4a, 4b...Ring, 5...
...Link, 6...Femally threaded pipe, 7...Male thread, 8...
...Heater receiver, 9...Slide bearing, 10
... shaft, 11 ... torque wrench, 12 ... link, 13 ... link, 14 ... torque wrench holder, 15 ... bracket, 16 ... cylinder, 17 ...
...Bracket, 18...Shaft, 19...Set screw,
20...Cut case, 21...Slide bearing, 30...Clamp stopper.

Claims (1)

[Claims] 1. In a fusion machine that heats and melts the fused surfaces of plastic tubes to be joined together, presses the tubes together at a prescribed pressure for a prescribed period of time, waits for them to cool and integrate, and then fuses the tubes together. A second clamp is provided which clamps the tube and is movable towards the first clamp held stationary by clamping the tube;
The clamp is provided with a torque wrench that moves and presses the first clamp placed in an immovable state that holds the pipe, and the torque wrench fixes the pipe at a position with a predetermined pressing force. Torque wrench retainers are attached, the clamps consisting of a pair of split rings, one fixed and the other pivoted, the split rings having a liner that grips the tube and fixed. A plastic pipe fusing machine characterized in that the split ring is provided with a clamp stopper for limiting the moving distance of the clamp.