Hot melting method applied to large-diameter pipe and hot melting device

Abstract

The invention discloses a hot melting method applied to a large-diameter pipe and a hot melting device, and belongs to the technical field of hot melting devices. The hot melting method and the hot melting device can meet the radial heating mode required by hot melting of the large-diameter pipe, further balance the melting degree of the pipe and a pipe fitting, facilitate welding of the pipe andthe pipe fitting, reduce the operation difficulty, improve the working efficiency, and are simple in structure and convenient to use. The method comprises the following steps that preheating is carried out; the pipe fitting is connected to the inner melting mold head of an inner melting assembly in a sleeving mode, and the pipe is connected to an outer melting mold head of an outer melting assembly in a sleeving mode; the inner melting assembly and the outer melting assembly are heated at the same time, meanwhile, the inner melting mold head carries out radial pressurization treatment on the inner wall of the pipe fitting outward, and the outer melting mold head carries out radial extrusion treatment on the outer wall of the pipe inward; and after the inner surface of the pipe fitting andthe outer surface of the pipe reach the preset melting degree, the pipe fitting and the pipe are pulled out of the hot melting device, and the melting end of the pipe is rapidly connected to the melting end of the pipe fitting in a sleeving mode.

Description

technical field [0001] The invention relates to the technical field of hot-melt devices, in particular to a hot-melt method and a hot-melt device applied to large-diameter pipes. Background technique [0002] The hot melter is a professional welding tool used for heating and melting thermoplastic pipes and molds and then connecting them. The fuser plays a vital role in the process of connecting pipes and fittings. It is mainly used for welding pipe fittings such as PVC pipes and PE pipes. The current hot melter in the market is still very useful for pipes with a diameter of less than 40mm, but for pipes with a diameter greater than 90mm, its defects are also very obvious. [0003] In the actual use of the pipe, the pipe layout needs to be designed. At this time, the pipe fittings are required to be used together with the adapter. The working principle of the common fuser is: the operator holds the pipe with one hand and the pipe fitting with the other hand, and at the same ...

AI Technical Summary

Problems solved by technology

[0005] One: Due to the long heating time of large-diameter pipes, and the different wall thicknesses of pipes and fittings, the heating degree of the pipes meets the requirements within the same time period, but the heating degree of the pipe fittings is not enough, the welding effect is not good and it is easy to fall off; extend the heating time , then the pipe is easily melted and deformed, resulting in material scrap;

[0006] Two: Large-diameter pipes are not easy to handle and easy to get out of hands, not to mention that the operator needs to hold the pipe with one hand and the pipe fitting with the other, and at the same time connect the pipe fittings and pipes to the melting joints at the left and right ends of the fuser. It is difficult to construct, and Heated pipes and fittings need more force to be socketed, which has a greater impact on the welding effect;

[0007] Three: When large-diameter pipes and fittings are socketed, it is easy to extrude part of the material on the inner wall of the pipe fittings to form a bulge. The bulge will affect the flow rate of the fluid in the pipe. At this time, the fluid will exert force on the interface. Over time, the pipe at the weld will fall off

[0010] At the same temperature, the heat carried is less, and the cross-sectional area of ​​the pipe is much larger than that of the pipe, so the heat is transferred and lost more; while the pipe is just the opposite, the weight of the hot-melt die head is relatively heavy, and the heat contained in the die head at the same temperature There are many, but the cross-sectional area of ​​the pipe is usually smaller, and the heat transfer loss is less, so the melting speed on both sides is usually fast or slow, which will affect the quality of the construction

At the same time, when the die head is pressed in, there is often a large axis deviation and shaking due to the operator or the clamping tool, resulting in uneven melting of the joint surface and insufficient effective contact surface, resulting in quality accidents

[0011] This gradual hot melting method will push a certain amount of molten waste to the inner wall of the pipe fittings and the root of the pipe socket, affecting the smoothness of the inner wall and the appearance of the pipe fittings. Another disadvantage of this method is that it takes a lot of time to weld large diameter pipes. The axial thrust can make the pipe and fitting melt, and it is usually difficult to operate when it reaches the size of 110mm, so usually only the butt welding method with relatively low welding strength or the electrofusion fitting with higher cost and poor strength can be selected for the size above 110mm. Connection, the inner wall of the electrofusion joint socket is covered with a resistance wire, which fits with the small gap of the pipe, the pipe is inserted into the pipe in advance, and then energized and heated to the resistance wire for a certain period of time to melt and bond the joint of the pipe and pipe into one body to achieve the sealing and pressure bearing effect. The main disadvantages are that the manufacturing cost of pipe fittings is high, the cost of large-scale PE pipes is high, and the dimensional tolerances of the processed pipes are relatively large. There is no compressive force on the joint surface of the pipe fittings, which makes the pressure bearing strength of the welded joint poor, let alone the welding of large-diameter pipes

Images