JPS6056612B2 - Butt welding equipment - Google Patents

Abstract

PURPOSE:To butt-weld thermoplastic resin pipes without causing stepped part in the joint, by welding thermoplastic resin pipes of reformed round cross sections to be welded together with a given pressure applied. CONSTITUTION:The movable clamp 3 is fixed on the bed plate 1 at a proper distance from the fixed clamp 2, and the upper halves of the clamps 2 and 3 are opened to set the thermoplastic resin pipes projected from the sides of the clamps 2 and 3. The upper halves of the clamps 2 and 3 are then closed to hold the pipes 5, whose ends are reformed into round cross sectional shapes by the pressure applied to the end outer walls with the plural adjusting bolts 21 and 31 on the clamps 2 and 3. The radius of gyration of the cutting tools 61 of the rotating chamfering machine 6 is adjusted to the radius for the cutting and chamfering, and the tools 61 are rotated to cut and chamfer the pipe ends simultaneously. The machine 6 is then removed, and the hot plate 7 is inserted between the pipes 5. The pipe ends are pressed to the hot plate 7 by the pressing machine 4 under a given pressure, locked by the locking device 44, and butt-welded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pad welding device suitable for thermally welding thermoplastic resin pipes, particularly polyethylene pipes together.

Conventionally, this type of pad welding apparatus is known in which a fixed clamp and a movable clamp are disposed on a base plate, and the movable clamp is moved by the operation of an air cylinder or a hydraulic cylinder.

When heat welding thermoplastic resin pipes together, the ends of the thermoplastic resin pipes are held in a slightly protruding state between a fixed clamp and a movable clamp, and the end faces of each thermoplastic resin pipe are chamfered. Thereafter, each tube end surface was pressed against a hot plate to heat and melt it, and then the molten tube end surfaces were butted together and welded and joined.

By the way, when the thermoplastic resin pipe to be heat welded is a polyethylene pipe, the polyethylene pipe is very soft even at room temperature, so it is easily deformed by external force, and in particular, a pipe with a thin wall thickness may not be the original perfect circle. It is deformed into a flat shape.

Therefore, when holding polyethylene pipes that have been deformed into a flat shape in this manner in the welding device and joining them, simply holding the pipes in the clamps will not make the ends of the pipes protruding from the sides of the clamps perfectly round. . Therefore, as a result of butt-joining the tubes that have been deformed into a flat shape, a step inevitably occurs on the inner circumferential surface of the tube joint, and there is a problem in that this portion becomes clogged with foreign matter. Moreover, since both tube end surfaces are joined in an eccentric state at the same time, the substantial joint area where both tube end surfaces are welded is reduced, and sufficient joint strength cannot be obtained.

Therefore, when vibrations, shocks, etc. are applied to this pipe joint, cracks may occur in this joint. Furthermore, in conventional pad welding equipment, the movable clamp was moved and pressed by operating an air cylinder or hydraulic cylinder, so when pressing the end face of the thermoplastic resin pipe against the hot plate to melt it, Alternatively, when welding and joining the molten tube end surfaces together, there is a problem in that it is difficult to apply an appropriate pressing force according to the diameter size of the tube and to finely adjust it.

Furthermore, if the operating mechanism of the movable clamp is an air cylinder or hydraulic type, the weight of the entire device increases and is inconvenient to carry, making it unsuitable for on-site piping construction. The present invention solves all of the problems faced by such conventional devices at once, and consists of a fixed clamp and a movable clamp arranged in a straight line on a base plate, and these clamps have a thermoplastic An adjustment bolt is provided that applies pressing force to the outer wall of the resin pipe to correct the tip of the pipe to a perfect circle, making it possible to weld and join each pipe while keeping the joint end faces of each pipe perfectly circular and concentric. This is what I did.

In addition, the movable clamp is equipped with a torque wrench for moving toward the fixed clamp side and applying pressing force, and a manual pressing machine equipped with a locking mechanism to maintain the pressing force of the torque wrench. It can apply an appropriate pressing force depending on the diameter size, and the entire device is lightweight so that it can be easily carried when constructing piping on site. The present invention provides a pad welding device equipped with a rotary chamfering machine and a hot plate.

EMBODIMENT OF THE INVENTION Hereinafter, the specific structure of this invention is demonstrated in detail based on an Example.

Fig. 1 is a partially cutaway front view of a pad welding device showing an embodiment of the present invention, and Fig. 2 is a partially cutaway front view showing a rotary chamfering mechanism in use. 2 is a fixed clamp, 3 is a movable clamp, 4 is a manual presser, 5 is a thermoplastic resin tube, 6 is a rotary chamfering machine, and 7 is a hot plate.

The fixed clamp 2 and the movable clamp 3 are piped in a straight line on the base plate 1, the fixed clamp 2 is fixed to the base plate 1, and the movable clamp 3 is connected to the guide shaft 1 which is passed over the base plate 1.
It is now possible to move by being guided by 1.

These fixed clamps 2 and . - The pipe holding part of the movable clamp 3 has a half structure divided into upper and lower halves, and can be opened and closed by connecting a pin to one end, and has a locking mechanism (Fig. (not shown) allows the outer circumferential surface of the thermoplastic resin tube 5 to be securely held by each half member. Furthermore, a pressing force is applied to the opposing end of each clamp 2, 3 on the outer wall of the tube end of the held thermoplastic resin tube 5, and the tip of the tube protruding from the side surface of the clamp is corrected into a perfect circle. Adjustment bolts 21 and 31 are provided for this purpose.

The manual pressing machine 4 includes a torque wrench 41 and a locking mechanism 44.
The lower end of a torque wrench 41 made of elastic steel or the like is pivotally supported under the movable clamp 3, and a torque pointer is provided on the pivot.

43 is a handle of the torque wrench 41.

The movable clamp 3 has a pipe holding part and a lower part connected to each other in a slidable manner, and after fixing the lower part to the slide shaft 11,
When the torque wrench 41 is rotated toward the fixed clamp side, the upper tube holding portion can be made to protrude toward the fixed clamp side.

42 is a torque display plate provided on the upper part of the torque wrench 41, and when the torque wrench 41 is rotated, the movable clamp 3
The pressing force can be confirmed by reading the deflection weight of the torque wrench 41 with the torque pointer when a pressing force is applied to the torque wrench 41 .

On the other hand, the lock mechanism 44 is for maintaining the pressing force of the torque wrench 41, and has one end that is pivotally supported by the upper end of the torque wrench 41, and the other end that can be fixed to the base plate 1. ing. The rotary chamfering machine 6 is equipped with a cutting tool 61 that can cut the tube end face and chamfer the inner wall of the tube end.

The cutting tool 61 is linked to a worm shaft 62, and by rotating the handle 63 of the worm shaft 62, the cutting tool 61 can be moved in the radial direction (radial direction of the tube). Therefore, after adjusting the turning radius of the cutting tool 61 to correspond to the pipe diameter size of the thermoplastic resin pipe 5, the cutting tool 61
When rotated, cutting of the tube end surface and chamfering of the inner wall of the tube end can be performed at the same time. The pad welding apparatus of the present invention has the above-mentioned structure, and the process of welding pipes together using this apparatus will now be described with reference to FIGS. 1 and 2.

First, they are fixed to the respective thermoplastic resin pipes 5, 5, fixed clamp 2, and movable clamp 3.

At this time, the tip of the thermoplastic resin tube 5 is made to slightly protrude from the side surface of each clamp 2, 3 so as not to interfere with the welding operation. Next, the movable clamp 3 is moved to the fixed clamp 2 side, and the end surfaces of the thermoplastic resin tubes 5 and 6 held by the respective clamps 2 and 3 are butted together.

Then, by turning the adjustment bolts 21 and 31 provided on the fixed clamp 2 and the movable clamp 3, a pressing force is applied to the outer wall of the tube end, and the thermoplastic resin tubes 5 and 5 held in the respective clamps are
Correct the tip of the tube to a perfect circle and set it concentrically. In this way, after correcting the tube tips of the thermoplastic resin tubes 5, 5 held by each clamp into perfect circles, the movable clamp 3 is moved back, and a rotating surface is formed between the fixed clamp 2 and the movable clamp 3. Set the removal machine 6.

Then, by rotating this rotary chamfering machine 6, both pipes 5, 5 are
Cut the pipe end face and chamfer the inner wall of the pipe end. After that,
The rotary chamfering machine 6 is removed, and a hot plate 7 is interposed between the fixed clamp 2 and the movable clamp 3. After fixing the lower part of the movable clamp 3 to the guide shaft 11, the torque wrench 41 is rotated to make the tube holding part of the movable clamp 3 protrude toward the fixed clamp 2 side, and each thermoplastic material is attached to both sides of the hot plate 7. It is brought into contact with the end surfaces of the resin pipes 5, 5. In this way, the torque wrench 41 is further moved from the state in which the hot plate 7 is in contact with the tube end surface.
While reading the pressing force of the torque wrench 41 on the torque display plate 42, a predetermined pressing force corresponding to the pipe diameter size is applied to the hot plate 7, and the elastic deformation of the torque wrench 41 is fixed by the locking mechanism 44.

When the end face of the thermoplastic resin pipe 5 comes into pressure contact with the hot plate 7 and gradually melts, this molten resin is pushed in and out of the pipe end face, and as a result, the holding part of the movable clamp 3 moves somewhat toward the fixed clamp 2 side. Since elastic force is applied to the torque wrench 41, the thermoplastic resin tube 5 is pressed against the hot plate 7 with an appropriate pressing force that follows this movement and melts.

Therefore, the locking mechanism 44 is released and the torque wrench 41 is rotated in the opposite direction to quickly remove the hot plate 7.

Then, the torque wrench 41 is rotated again to cause the thermoplastic resin tube 5 held by the movable clamp 3 to protrude toward the fixed clamp 2 side, and the thermoplastic resin tube 5 held by the fixed clamp 2 is
Press it against the end face with a specified pressing force. Of course, when joining these pipes together, the pressing force is applied while reading the pressing force of the torque wrench 41 on the torque display plate 42 in the same manner as described above, and this pressing force is maintained by the locking mechanism 44 for a predetermined time. do.

In this way, the thermoplastic resin pipes 5, 5 held by the fixed clamp 2 and the movable clamp 3 are welded and joined in a perfect circle and concentrically.

As described above, in the pad welding device of the present invention, the fixed clamp and the movable clamp are arranged in a straight line on the base plate, and each clamp is provided with an adjustment bolt, so that by simply rotating the adjustment bolt, The tips of the tubes held by the respective clamps can be corrected to a perfect circle, and the tubes can be connected in a perfect circle and concentrically.

Moreover, the movable clamp is equipped with a torque wrench that moves it toward the fixed clamp and applies a pressing force, and a manual presser equipped with a locking mechanism to maintain this pressing force.
When press-welding tube ends to a hot plate or pressing molten tube ends together to butt-join them, it is possible to apply the optimal pressing force according to the diameter of the tube, and it is also easy to make fine adjustments. , an extremely strong welded joint can be obtained.

In addition, the device of the present invention has a simple structure because the movable clamp can be moved and pressed manually, and is much lighter than conventional air cylinder or hydraulic welding devices. It is convenient to carry and extremely suitable for on-site piping construction.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view of a pad welding device according to an embodiment of the present invention, and FIG. 2 is a partially cutaway front view showing a rotary chamfering machine in use. 1... Base plate, 11... Guide shaft, 2...
...Fixed clamp, 3...Movable clamp, 4...Manual press/machine, 41...Torque wrench, 42...Torque display board ,43...
...Handle, 44...Lock mechanism, 5...Thermoplastic resin pipe, 6...Rotary chamfering machine, 7...Hot plate.

Claims (1)

[Claims] 1 A fixed clamp and a movable clamp that hold a thermoplastic resin pipe are arranged in series on a base plate, and these clamps apply a pressing force to the outer wall of the pipe end of the pipe they are holding to correct the pipe tip into a perfect circle. The movable clamp is equipped with a torque wrench for applying a pressing force to move the moving clamp toward the fixed clamp, and a manual pressing machine equipped with a locking mechanism for maintaining the pressing force of the torque wrench. What is claimed is: 1. A butt welding device comprising: a rotary chamfering machine for cutting the end face of the thermoplastic resin pipe; and a hot plate.