A multi-stage heating device for thick-walled pipe welds

Abstract

The present invention belongs to the field of weld heating welding technology, and discloses a multi-stage heating device for thick-walled pipe welds, including a base, a coolant storage tank fixedly connected to the upper surface of the base, four evenly distributed table legs fixedly connected to the lower surface of the base, a support column and a curved pipe fixedly connected to the upper surface of the coolant storage tank, a straight pipe fixedly connected to one end of the curved pipe, a support column fixedly connected to one end of the straight pipe, a heating plate fixedly connected to the outer edge of the other end of the straight pipe, a temperature regulating and pressurizing mechanism fixedly connected to the curved pipe is provided inside the curved pipe, two sliding grooves are fixedly connected to the upper surface of the base, and a cylinder is fixedly connected to the lower surface of the base. The present invention can effectively control the temperature in the welding process through the principle of thermal expansion and contraction of the medium inside the shell when the temperature of the heating plate is too high, reduce heat waste, shorten welding time, and improve production efficiency through the design of the temperature regulating and pressurizing mechanism.

Description

Technical Field

[0001] The invention belongs to the technical field of weld heating and welding, and in particular relates to a multi-stage heating device for thick-walled pipe welds. Background Art

[0002] Thick-walled pipes are widely used in the fields of petroleum, natural gas, chemical industry, electric power, etc., such as oil pipelines, gas pipelines, pressure vessels, heat exchangers, etc. With the development of society and the growth of energy demand, the use of thick-walled pipes is increasing, and the demand for thick-walled pipe welding equipment is also increasing. Multi-stage heating technology can effectively control the heat input during welding, reduce welding deformation, reduce welding stress, and improve welding quality. Compared with traditional single-stage heating welding, multi-stage heating technology can improve welding efficiency and reduce welding costs. With the advancement of science and technology, thick-walled pipe multi-stage heating equipment will continue to develop and play an important role in more fields.

[0003] The existing multi-stage heating device for thick-walled pipe welds still has many defects: the existing multi-stage heating device for welds will produce a molten pool when performing multi-stage heating on the weld. The molten pool may cause molten pool pores due to many reasons such as welding materials or welding processes. The existing equipment can only perform repair welding or polishing after welding, which seriously affects the quality and strength of the weld, as well as the appearance quality and sealing of the weld, and may even pose a safety hazard; in addition, after the existing multi-stage heating device for welds sets the preset temperature, it is impossible to adjust the temperature during the process, which reduces the quality of welding, and may cause uneven heat input and excessive welding stress, increasing the risk of cracks or deformation in the weld joint. Summary of the invention

[0004] The object of the present invention is to provide a multi-stage heating device for thick-walled pipe welds to solve the problems raised in the above-mentioned background technology.

[0005] In order to achieve the above-mentioned purpose, the present invention provides the following technical solutions: a multi-stage heating device for thick-walled pipe welds, comprising a base, the upper surface of the base is fixedly connected to a coolant storage tank, the lower surface of the base is fixedly connected to four evenly distributed table legs, the upper surface of the coolant storage tank is fixedly connected to a support column and a bent pipe, one end of the bent pipe is fixedly connected to a straight pipe, the support column is fixedly connected to one end of the straight pipe, the other end of the straight pipe is fixedly connected to a heating plate on the outer edge, the bent pipe is provided with a temperature regulating and pressurizing mechanism fixedly connected thereto, the upper surface of the base is fixedly connected to two sliding grooves, the lower surface of the base is fixedly connected to a cylinder, the output end of the cylinder is fixedly connected to a connecting plate, one side of the connecting plate Two sliding blocks are fixedly connected, and the outer edge of the sliding block is clamped with the inner side of the sliding groove, and the upper surface of the base is fixedly connected with the first fixed seat and the second fixed seat, and the first movable rod is movably sleeved on the middle part of one end of the first fixed seat, and two connecting rods are movably sleeved on the outer circular surfaces of both ends of the first movable rod, and the first pulley is movably sleeved on the inner sides of the upper ends of the two groups of connecting rods, and the second pulley is movably sleeved on the inner sides of the lower ends of the two groups of connecting rods, and one end of the first pulley is fixedly connected to the first bevel gear, one side of one of the connecting rods is fixedly connected to the connecting seat, and one side of the connecting seat is movably sleeved with a rotating column, one end of the rotating column is fixedly connected to the second bevel gear, and one end of the second bevel gear is fixedly connected to the spiral block.

[0006] Preferably, a motor is fixedly connected to the upper surface of the base, a rotating rod is movably sleeved on the middle part of the output shaft end of the motor, a third bevel gear is fixedly connected to one end of the rotating rod, a connecting ring is movably sleeved on the outer circular surface of the rotating rod, and a linkage rod is movably sleeved on the inner side of one end of the connecting ring.

[0007] Preferably, one end of the linkage rod is fixedly connected to a fourth bevel gear, the outer circular surface of the linkage rod is fixedly connected to two third pulleys, the outer circular surface of the linkage rod is movably sleeved with two pulley bases, the inner sides of the protrusions of the two groups of pulley bases are movably sleeved with the third pulleys, and the lower surfaces of the two groups of pulley bases are fixedly connected to linkage blocks.

[0008] Preferably, the temperature regulating and pressurizing mechanism comprises a frame, a cylinder is threadedly connected to the inner side of one end of the frame, a spiral fan blade is fixedly connected to one end of the cylinder, an outer circular surface of the cylinder is fixedly connected to an outer shell, and the outer circular surface of the outer shell is movably connected to the middle part of one end of the frame.

[0009] Preferably, an upper piston is fixedly connected to one end of the outer cylindrical surface of the shell, one end of the first spring is fixedly connected to the lower surface of the upper piston, the other end of the first spring is fixedly connected to the inner side of one end of the frame, one end of the shell is fixedly connected to one end of the second spring, a movable rod is movably sleeved in the middle of one end of the shell, one end of the movable rod is fixedly connected to the lower piston, and the upper surface of the lower piston is fixedly connected to the other end of the second spring.

[0010] Preferably, the first bevel gear is meshed with the second bevel gear, the third bevel gear is meshed with the fourth bevel gear, and the second pulley is placed on the inclined surface of the linkage block.

[0011] Preferably, the outer circumferential surface of the cylinder is provided with equidistant thread grooves, the linkage block is an irregular geometric body, and the two inclined surfaces of the linkage block in contact with the second pulley have the same inclination angle.

[0012] Preferably, the shell has phase change material stored inside, common ones include paraffin, acetate, stearic acid, etc., and the material inside the shell can be selected according to the set temperature of the heating plate.

[0013] Preferably, a first baffle is fixedly connected inside the shell, a second baffle is movably sleeved on the inner wall of the shell, a medium is stored between the first baffle and the second baffle, and one end of the movable rod is fixedly connected to the second baffle.

[0014] The beneficial effects of the present invention are as follows:

[0015] 1. The present invention, through the design of the sliding block and the linkage block, can make the sliding block push the linkage block to move upward under the push of the cylinder, and the linkage block acts on the second pulley to make the connecting rod move toward each other, thereby realizing the clamping function of the pipeline. At this time, the rotation of the motor drives the rotation of the third bevel gear and the fourth bevel gear, and the fourth bevel gear drives the rotation of the third pulley through the linkage rod, and the rotation of the pipeline is realized through the friction between the third pulley and the outer wall of the pipeline. The rotation of the pipeline drives the rotation of the first pulley, thereby making the first pulley rotate. The first pulley realizes the rotation effect of the spiral block through the linkage relationship between the first bevel gear and the second bevel gear, thereby increasing the fluidity of the molten pool. The uniform molten pool can reduce the stress concentration inside the welded joint, reduce the risk of welding deformation and cracks, accelerate the diffusion of gas in the molten pool, make the gas more easily float to the surface, and reduce the formation of pores.

[0016] 2. The present invention adopts the design of the temperature regulating and pressurizing mechanism. When the temperature of the heating plate is too high, through the principle of thermal expansion and contraction of the medium inside the shell, when the coolant gradually rises with the temperature of the heating plate, the internal medium expands and acts on one end of the lower piston. At this time, the shell drives the cylinder to move, the lower piston is closed and the upper piston is opened, so that the coolant is re-injected, thereby achieving the effect of temperature control, effectively controlling the temperature in the welding process, reducing heat waste, shortening the welding time, and improving production efficiency. At the same time, when the upper piston is opened, the cylinder will also drive the spiral fan blades to rotate, thereby realizing the absorption of the coolant, avoiding the problem of untimely or no injection of the coolant, accelerating the work efficiency and avoiding the situation where the piston cannot be opened due to aging. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0018] Figure 2 For the present invention Figure 1 The enlarged schematic diagram at A in the middle;

[0019] Figure 3 For the present invention Figure 1 The enlarged schematic diagram of point B in the middle;

[0020] Figure 4 It is a partial structural schematic diagram of the present invention;

[0021] Figure 5 For the present invention Figure 4 The enlarged schematic diagram at C in the middle;

[0022] Figure 6 It is a left view of a part of the structure of the present invention;

[0023] Figure 7 For the present invention Figure 6 The enlarged schematic diagram at D in the middle;

[0024] Figure 8 It is a left view of the connecting rod structure of the present invention;

[0025] Fig. 9 A schematic cross-sectional view of the internal structure of the housing of the present invention;

[0026] Fig.10 The overall structure diagram of the temperature regulating and pressurizing mechanism of the present invention is as follows

[0027] In the figure: 1, base; 2, coolant storage tank; 3, elbow; 4, heating plate; 5, sliding groove; 6, cylinder; 7, sliding block; 8, first fixed seat; 9, second fixed seat; 10, connecting rod; 11, first pulley; 12, second pulley; 13, first bevel gear; 14, connecting seat; 15, second bevel gear; 16, spiral block; 17, motor; 18, third bevel gear; 19, connecting ring; 20, linkage rod; 21, third pulley; 22, linkage block; 23, frame; 24, cylinder; 25, shell; 26, upper piston; 27, first spring; 28, second spring; 29, lower piston; 30, fourth bevel gear; 31, spiral blade; 32, pulley base; 33, straight pipe; 34, support column; 35, first baffle; 36, second baffle; 37, movable rod. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] like Figures 1 to 10As shown, an embodiment of the present invention provides a multi-stage heating device for thick-walled pipe welds, including a base 1, a coolant storage tank 2 is fixedly connected to the upper surface of the base 1, four evenly distributed table legs are fixedly connected to the lower surface of the base 1, a support column 34 and a bent pipe 3 are fixedly connected to the upper surface of the coolant storage tank 2, one end of the bent pipe 3 is fixedly connected to a straight pipe 33, the support column 34 is fixedly connected to one end of the straight pipe 33, a heating plate 4 is fixedly connected to the outer edge of the other end of the straight pipe 33, a temperature regulating and pressurizing mechanism fixedly connected to the bent pipe 3 is provided inside the bent pipe 3, two sliding grooves 5 are fixedly connected to the upper surface of the base 1, a cylinder 6 is fixedly connected to the lower surface of the base 1, an output end of the cylinder 6 is fixedly connected to a connecting plate, two sliding blocks 7 are fixedly connected to one side of the connecting plate, the outer edge of the sliding block 7 is clamped with the inner side of the sliding groove 5, a first fixed seat 8 is fixedly connected to the upper surface of the base 1, The second fixed seat 9 and the first fixed seat 8 are movably sleeved with the first movable rod in the middle of one end, and two connecting rods 10 are movably sleeved on the outer cylindrical surfaces of both ends of the first movable rod, the first pulley 11 is movably sleeved on the inner side of the upper ends of the two groups of connecting rods 10, and the second pulley 12 is movably sleeved on the inner side of the lower ends of the two groups of connecting rods 10, and one end of the first pulley 11 is fixedly connected to the first bevel gear 13, one side of one of the connecting rods 10 is fixedly connected to a connecting seat 14, one side of the connecting seat 14 is movably sleeved with a rotating column, one end of the rotating column is fixedly connected to the second bevel gear 15, the first bevel gear 13 is meshed with the second bevel gear 15, the third bevel gear 18 is meshed with the fourth bevel gear 30, the second pulley 12 is placed on the inclined surface of the linkage block 22, the second pulley 12 is kept in contact with the inclined surface of the linkage block 22, and one end of the second bevel gear 15 is fixedly connected to the spiral block 16.

[0030] Among them, the upper surface of the base 1 is fixedly connected to a motor 17, a rotating rod is movably sleeved in the middle of the output shaft end of the motor 17, one end of the rotating rod is fixedly connected to a third bevel gear 18, a connecting ring 19 is movably sleeved on the outer cylindrical surface of the rotating rod, a linkage rod 20 is movably sleeved on the inner side of one end of the connecting ring 19, one end of the linkage rod 20 is fixedly connected to a fourth bevel gear 30, two third pulleys 21 are fixedly connected to the outer cylindrical surface of the linkage rod 20, two pulley bases 32 are movably sleeved on the outer cylindrical surface of the linkage rod 20, the inner sides of the protrusions of the two groups of pulley bases 32 are movably sleeved with the third pulley 21, and the lower surfaces of the two groups of pulley bases 32 are fixedly connected to a linkage block 22, driving the cylinder 6, the output shaft end of the cylinder 6 drives the connecting plate to move, the connecting plate drives the two sliding blocks 7 to move, the sliding block 7 acts on the bottom inclined surface of the linkage block 22, so that the linkage block 22 is displaced upward, and the linkage block 22 passes By acting on the two second pulleys 12, the second pulley 12 drives the four groups of connecting rods 10 to move relative to each other, thereby realizing the clamping of the pipeline. At this time, the driving motor 17, the output shaft end of the motor 17 drives the third bevel gear 18 to rotate, the third bevel gear 18 drives the fourth bevel gear 30 to rotate, and the fourth bevel gear 30 drives the third pulley 21 to rotate through the linkage rod 20. Under the action of the friction between the two third pulleys 21 and the pipeline, the rotation of the pipeline is realized, which is convenient for welding the weld. Since the rotation of the pipeline also drives the rotation of the first pulley 11, the first pulley 11 drives the first bevel gear 13 to rotate, the first bevel gear 13 drives the second bevel gear 15 to rotate, and the second bevel gear 15 drives the spiral block to rotate, acting on the unsolidified weld molten pool that has just been welded, realizing the stirring of the unsolidified molten pool, promoting the diffusion of gas and increasing the flow performance of the molten pool.

[0031] The temperature regulating and pressurizing mechanism includes a frame 23, a cylinder 24 is threadedly connected to the inner side of one end of the frame 23, a spiral blade 31 is fixedly connected to one end of the cylinder 24, a shell 25 is fixedly connected to the outer circumferential surface of the cylinder 24, and the outer circumferential surface of the shell 25 is movably sleeved with the middle part of one end of the frame 23, an upper piston 26 is fixedly connected to one end of the outer circumferential surface of the shell 25, and one end of the upper piston 26 is fixedly connected to one end of the first spring 27 on the lower surface, and the other end of the first spring 27 is fixedly connected to the inner side of one end of the frame 23, one end of the shell 25 is fixedly connected to one end of the second spring 28, and a movable rod 37 is movably sleeved in the middle part of one end of the shell 25, and one end of the movable rod 37 is fixedly connected to the lower piston 29, and the upper surface of the lower piston 29 is fixedly connected to the other end of the second spring 28. The surface is provided with equidistant thread grooves, the linkage block 22 is an irregular geometric body, and the two inclined surfaces of the linkage block 22 in contact with the second pulley 12 have the same inclination angle. When the heating plate 4 performs multi-stage heating, the lower piston 29 is opened at this time, and the coolant forms an upper circuit. When the coolant temperature is heated to a preset value by the heating plate, when the coolant flows through the outer shell 25, the medium inside the outer shell 25 expands and contracts due to heat and cold, and the second baffle 36 drives the movable rod 37 to move, so that the cylinder 24 moves under the action of the first spring 27 and the outer shell 25, and the outer shell 25 drives the upper piston 26 to move. The cylinder 24 drives the spiral fan blades 31 to rotate due to the action of the thread, so that the pressure difference in the pipeline realizes the extraction of the coolant in the coolant storage tank 2, and the new coolant flows into the straight pipe 33 to achieve the cooling effect.

[0032] Among them, phase change materials are stored inside the shell 25, common ones are paraffin, acetate, stearic acid, etc., and the internal material of the shell 25 can be selected according to the set temperature of the heating plate 4. The phase change material can absorb or release a large amount of heat during the phase change process, and its heat storage density is much higher than that of traditional materials. The phase change process of the phase change material is reversible, and it can repeatedly absorb and release heat to achieve the storage and release of thermal energy.

[0033] Among them, the inside of the shell 25 is fixedly connected with a first baffle 35, the inner wall of the shell 25 is movably sleeved with a second baffle 36, and a medium is stored between the first baffle 35 and the second baffle 36. One end of the movable rod 37 is fixedly connected to the second baffle 36. Through the principle of thermal expansion and contraction of the medium, the second baffle 36 moves, thereby driving the movable rod 37 to move. The movable rod 37 drives the shell 25 to move through the second spring 28, thereby realizing the closing and opening of the upper piston 26 and the lower piston 29.

[0034] Working principle:

[0035] When the equipment is operating normally, the workpiece to be welded is first placed on the third pulley 21, and the cylinder 6 is driven. The output shaft end of the cylinder 6 drives the connecting plate to move, and the connecting plate drives the two sliding blocks 7 to move. The sliding block 7 acts on the bottom inclined surface of the linkage block 22, so that the linkage block 22 moves upward. The linkage block 22 acts on the two second pulleys 12, and the second pulleys 12 drive the four groups of connecting rods 10 to move relative to each other, thereby achieving the clamping of the pipeline. At this time, the motor 17 is driven, and the output shaft end of the motor 17 drives the third bevel gear 18 to rotate, and the third bevel gear 18 drives the fourth bevel gear 30 The fourth bevel gear 30 drives the third pulley 21 to rotate through the linkage rod 20. Under the action of the friction between the two third pulleys 21 and the pipeline, the pipeline is rotated, which is convenient for welding the weld. Since the rotation of the pipeline also drives the rotation of the first pulley 11, the first pulley 11 drives the first bevel gear 13 to rotate, the first bevel gear 13 drives the second bevel gear 15 to rotate, and the second bevel gear 15 drives the spiral block to rotate, which acts on the unsolidified weld molten pool just welded, realizes the stirring of the unsolidified molten pool, promotes the diffusion of gas and increases the flow performance of the molten pool.

[0036] In addition, when the heating plate 4 performs multi-stage heating, the lower piston 29 is opened and the coolant forms an upper circuit. When the coolant temperature is heated to a preset value by the heating plate, when the coolant flows through the outer shell 25, the medium inside the outer shell 25 expands and contracts due to heat and cold, and the second baffle 36 drives the movable rod 37 to move, so that the cylinder 24 moves under the action of the first spring 27 and the outer shell 25, and the outer shell 25 drives the upper piston 26 to move. The cylinder 24 drives the spiral fan blades 31 to rotate due to the action of the thread, so that the pressure difference in the pipeline realizes the extraction of coolant in the coolant storage tank 2, and the new coolant flows into the straight pipe 33 to achieve the cooling effect.

[0037] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0038] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A multi-stage heating device for thick-walled pipe welds, comprising a base (1), the upper surface of the base (1) being fixedly connected to a coolant storage tank (2), the lower surface of the base (1) being fixedly connected to four evenly distributed table legs, the upper surface of the coolant storage tank (2) being fixedly connected to a support column (34) and a curved pipe (3), one end of the curved pipe (3) being fixedly connected to a straight pipe (33), the support column (34) being fixedly connected to one end of the straight pipe (33), and the other end of the straight pipe (33) being fixedly connected to an outer edge thereof with a heating plate (4), characterized in that: The bent pipe (3) is provided with a temperature regulating and pressurizing mechanism fixedly connected thereto; the upper surface of the base (1) is fixedly connected with two sliding grooves (5); the lower surface of the base (1) is fixedly connected with a cylinder (6); the output end of the cylinder (6) is fixedly connected with a connecting plate; one side of the connecting plate is fixedly connected with two sliding blocks (7); the outer edges of the sliding blocks (7) are clamped with the inner sides of the sliding grooves (5); the upper surface of the base (1) is fixedly connected with a first fixed seat (8) and a second fixed seat (9); a first movable rod is movably sleeved at the middle of one end of the first fixed seat (8); the first movable rod is Two connecting rods (10) are movably sleeved on the outer circular surfaces at both ends; a first pulley (11) is movably sleeved on the inner sides of the upper ends of the two groups of connecting rods (10); a second pulley (12) is movably sleeved on the inner sides of the lower ends of the two groups of connecting rods (10); one end of the first pulley (11) is fixedly connected to a first bevel gear (13); one side of one of the connecting rods (10) is fixedly connected to a connecting seat (14); one side of the connecting seat (14) is movably sleeved with a rotating column; one end of the rotating column is fixedly connected to a second bevel gear (15); and one end of the second bevel gear (15) is fixedly connected to a spiral block (16).

2. A thick-walled pipe weld multi-stage heating device according to claim 1, characterized in that: The upper surface of the base (1) is fixedly connected to a motor (17); a rotating rod is movably sleeved at the middle of the output shaft end of the motor (17); a third bevel gear (18) is fixedly connected to one end of the rotating rod; a connecting ring (19) is movably sleeved on the outer circumferential surface of the rotating rod; and a linkage rod (20) is movably sleeved on the inner side of one end of the connecting ring (19).

3. A thick-walled pipe weld multi-stage heating device according to claim 2, characterized in that: One end of the linkage rod (20) is fixedly connected to a fourth bevel gear (30); the outer circumferential surface of the linkage rod (20) is fixedly connected to two third pulleys (21); the outer circumferential surface of the linkage rod (20) is movably sleeved with two pulley bases (32); the inner sides of the protrusions of the two groups of pulley bases (32) are movably sleeved with the third pulleys (21); and the lower surfaces of the two groups of pulley bases (32) are fixedly connected to linkage blocks (22).

4. A thick-walled pipe weld multi-stage heating device according to claim 3, characterized in that: The temperature regulating and pressurizing mechanism comprises a frame (23), the inner side of one end of the frame (23) being threadedly connected to a cylinder (24), one end of the cylinder (24) being fixedly connected to a spiral blade (31), the outer circumferential surface of the cylinder (24) being fixedly connected to an outer shell (25), and the outer circumferential surface of the outer shell (25) being movably sleeved to the middle portion of one end of the frame (23).

5. A thick-walled pipe weld multi-stage heating device according to claim 4, characterized in that: An upper piston (26) is fixedly connected to one end of the outer cylindrical surface of the housing (25); one end of a first spring (27) is fixedly connected to the lower surface of the upper piston (26); the other end of the first spring (27) is fixedly connected to the inner side of one end of the frame (23); one end of the housing (25) is fixedly connected to one end of a second spring (28); a movable rod (37) is movably sleeved in the middle of one end of the housing (25); one end of the movable rod (37) is fixedly connected to a lower piston (29); and the upper surface of the lower piston (29) is fixedly connected to the other end of the second spring (28).

6. A thick-walled pipe weld multi-stage heating device according to claim 5, characterized in that: The first bevel gear (13) meshes with the second bevel gear (15), the third bevel gear (18) meshes with the fourth bevel gear (30), and the second pulley (12) is placed on the inclined surface of the linkage block (22).

7. A thick-walled pipe weld multi-stage heating device according to claim 6, characterized in that: The outer circumferential surface of the cylinder (24) is provided with equidistant thread grooves, the linkage block (22) is an irregular geometric body, and the two inclined surfaces of the linkage block (22) in contact with the second pulley (12) have the same inclination angle.

8. A thick-walled pipe weld multi-stage heating device according to claim 7, characterized in that: Phase change material is stored inside the shell (25), and common materials include paraffin, acetate, stearic acid, etc. The material inside the shell (25) can be selected according to the set temperature of the heating plate (4).

9. A thick-walled pipe weld multi-stage heating device according to claim 8, characterized in that: A first baffle (35) is fixedly connected to the interior of the housing (25), a second baffle (36) is movably sleeved on the inner wall of the housing (25), a medium is stored between the first baffle (35) and the second baffle (36), and one end of the movable rod (37) is fixedly connected to the second baffle (36).

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