A single-head electric heating tube structure with built-in temperature probe and a manufacturing method thereof

Abstract

The present invention belongs to the technical field of heaters, and specifically relates to a single-head electric heating tube structure with a built-in temperature probe and a manufacturing method thereof. It comprises a stainless steel tube after a diameter reduction treatment, a resistance wire is arranged in the tube body and is filled with magnesium oxide powder, the two ends of the resistance wire are respectively connected to an upper lead rod and a lower lead rod, and the lower lead rod is connected to a thermal fuse and an NTC temperature probe; there are four lower lead rods, two of which are respectively welded to the two ends of the thermal fuse to form a U-shaped loop; the other two are welded to the two ends of the NTC temperature probe to form another U-shaped loop, and the two U-shaped loops are arranged in a PE sheath, connected in parallel with each other and not in contact with each other. The present invention also provides a method for manufacturing the above-mentioned single-head electric heating tube structure. The present invention has the advantages of good consistency, simple manufacturing process, low scrap rate, better performance, cost saving, large temperature detection range, uniform heating, etc.

Description

Technical Field

[0001] The invention belongs to the technical field of heaters, and in particular relates to a single-head electric heating tube structure with a built-in temperature probe and a manufacturing method thereof. Background Art

[0002] With the improvement of living standards, electric heating equipment is becoming more and more popular in areas without collective heating. There are more and more types of heating elements on electric heating equipment, especially electric heating tubes. The market demand is increasing rapidly. Existing products on the market with the same functions as the present invention generally have the following disadvantages:

[0003] 1. The products of this structure are produced by assembling magnesium oxide rods with resistance wires and filling powder. The assembly is time-consuming and labor-intensive, especially for products with longer tubes. The assembly of magnesium oxide rods becomes increasingly difficult during the assembly process, is greatly affected by human factors, has poor stability, a high scrap rate, and very low production efficiency. It is not suitable for large-scale production and also makes the production cost too high.

[0004] 2. The thermal fuse and the lower lead rod, the upper lead rod and the power cord and NTC connecting wire, and the NTC temperature probe and the resistance wire are all connected by riveting. During the process of shrinking the diameter, the length of the heating tube is stretched, and the riveting point is easily disconnected due to stress.

[0005] 3. Use a soft sleeve to fix the thermal fuse and NTC temperature probe. During the powder filling process, magnesium oxide powder will fall into the gap between the soft sleeve and the stainless steel tube, which may cause the internal parts of the sleeve to be crushed during the shrinking process.

[0006] 4. Because the upper lead rod is connected to the power cord and the NTC connecting wire by riveting, the riveting point is inside the heating tube, and the power cord and the NTC connecting wire are relatively soft, they are easy to be tangled together during the assembly process, and are easily stretched and damaged during the diameter reduction process, resulting in a high scrap rate. Summary of the invention

[0007] The technical problem to be solved by the present invention is to overcome the deficiencies in the prior art and provide a single-head electric heating tube structure with a built-in temperature probe and a manufacturing method thereof.

[0008] In order to solve the above technical problems, the solution adopted by the present invention is:

[0009] Provided is a single-head electric heating tube structure with a built-in temperature probe, comprising a stainless steel tube that has been reduced in diameter, a bottom cover at one end of the tube body, a flange at the other end, and a sealing material at the flange end of the tube mouth; a resistance wire is arranged in the tube body and filled with magnesium oxide powder, the two ends of the resistance wire are respectively connected to an upper lead rod and a lower lead rod, the lower lead rod is connected to a thermal fuse and an NTC temperature probe, the upper lead rod is connected to a power line and one end of an NTC connecting line, and the other ends of the power line and the NTC connecting line extend out of the tube; further comprising a PE sheath and a PE centering ring; there are four lower lead rods, two of which are respectively welded to the two ends of the thermal fuse to form a U-shaped loop; the other two are welded to the two ends of the NTC temperature probe to form another U-shaped loop, the two U-shaped loops are arranged in the PE sheath, are connected in parallel and do not contact each other; the PE sheath is open at one end of the tube sheath structure, the PE centering ring comprises a sleeve ring, the sleeve ring is installed in the open end of the PE sheath, four tube sheaths with parallel axes are jointly arranged in the sleeve ring, and the middle parts of the four lower lead rods are respectively sleeved in the four tube sheaths.

[0010] As an improvement, the thermal fuse and the NTC temperature probe are connected to the lower lead rod through terminal welding.

[0011] As an improvement, the outer diameter of the PE sheath is smaller than the inner diameter of the stainless steel pipe after the diameter reduction treatment.

[0012] As an improvement, the portion of the lower guide rod passing through the tube sleeve is also sleeved with fragile steatite fixing beads, which are used to ensure that there is a distance between the lower guide rods and between the lower guide rods and the tube wall.

[0013] As an improvement, the power line and the connecting line extend out of the stainless steel tube and are connected with a quick-connect plug; the single-head electric heating tube structure is also provided with a grounding wire.

[0014] As an improvement, the diameter of the PE centering ring is larger than the inner diameter of the stainless steel pipe after the diameter reduction treatment.

[0015] As an improvement, a groove is provided on the inner wall of the opening end of the PE sheath, the PE centering ring is trumpet-shaped and has a step structure on the outside, which can cooperate with the groove of the PE sheath pipe mouth; the four pipe sleeves in the PE centering ring are arranged in a cross shape and have different lengths to avoid the gap between the four guide rods being too small due to the presence of welding points.

[0016] A method for manufacturing the above-mentioned single-head electric heating tube structure, comprising the following steps:

[0017] (1) The joints of the thermal fuse and the NTC temperature probe are first riveted onto the terminals, then welded to the four lower lead rods respectively, and then the thermal fuse and the NTC temperature probe are installed into the PE centering ring and the PE sheath;

[0018] (2) One end of the resistance wire is welded to the upper lead rod, and the other end is welded to the lower lead rod. Then the assembly is hung on the automatic powder filling machine through the hook on the upper lead rod, and the stainless steel tube with the welded bottom cover is put on to fill the magnesium oxide powder;

[0019] (3) After filling the powder, seal the pipe mouth with a silicone plug, and then use a tube shrinking machine to reduce the diameter of the pipe body, and then weld the power line and NTC connecting line to the exposed upper guide rod, and finally rivet the flange and seal it with sealing material.

[0020] The principle of the present invention is:

[0021] The thermal fuse and NTC temperature probe are connected to the welded lower lead rod, and the welded upper lead rod is connected to the power line and NTC connecting wire by welding, which can effectively enhance the connection strength and ensure that the connection point is not broken during the diameter reduction process. The welding process of the power line and NTC connecting wire to the welded upper lead rod is carried out after the diameter reduction, and the welding is carried out outside the nozzle of the heating tube, which completely avoids the problem of the welding area and the wire being twisted together and damaged due to the diameter reduction.

[0022] The independently designed PE sheath and PE centering ring can meet the requirements of insulation and production process. At the same time, the PE centering ring can effectively prevent magnesium oxide powder from entering the gap between the PE sheath and the stainless steel pipe. The outer diameter of the PE sheath is smaller than the inner diameter of the stainless steel pipe after diameter reduction, thereby ensuring that the thermal fuse and NTC temperature probe are not squeezed during the diameter reduction process, effectively reducing the scrap rate.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The invention has the advantages of good consistency, simple manufacturing process, low scrap rate, better performance, cost saving, large temperature detection range, uniform heating, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of an existing electric heating tube;

[0026] Figure 2 It is a schematic diagram of the structure of the electric heating tube of the present invention (the connection method exposed outside the tube is a soft wire);

[0027] Figure 3 It is a right side view of the electric heating tube of the present invention (the connection method exposed outside the tube is a soft wire);

[0028] Figure 4 It is a schematic diagram of the structure of the electric heating tube of the present invention (the connection method exposed outside the tube is a quick-connect plug);

[0029] Figure 5 It is a right side view of the electric heating tube of the present invention (the connection method exposed outside the tube is a quick-connect plug);

[0030] Figure 6 It is a structural schematic diagram of the assembly of a PE center protection ring, a PE sheath, a thermal fuse, an NTC temperature probe and a lower lead rod in the present invention.

[0031] Figure 7 It is a schematic diagram of the structure of the PE sheath in the present invention;

[0032] Figure 8 It is a schematic diagram of the structure of the PE centering ring in the present invention.

[0033] Description of reference numerals:

[0034] 1- bottom cover, 2- stainless steel tube, 3- thermal fuse, 4- NTC temperature probe, 5- terminal, 6- magnesium oxide powder, 7- resistance wire, 8- silicone plug, 9- ground wire, 10- flange, 11- epoxy resin glue, 12- power cord, 13- NTC connecting wire, 14- quick connect plug, 15- PE sheath, 16- PE centering ring, 17- fragile talc fixing bead, 18- lower lead rod, 19- upper lead rod, 20- heat shrink sheath, 21- magnesium oxide rod, 22- ground pin, 23- NTC pin, 24- power cord pin. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments:

[0036] like Figure 1 As shown, a single-head electric heating tube structure with a built-in temperature probe in the prior art includes a stainless steel tube 2 after diameter reduction treatment, a bottom cover 1 is provided at one end of the stainless steel tube 2, and a flange 10 is provided on the outside of the other end. The upper lead rod 19 and the lower lead rod 18 are riveted and connected by a resistance wire 7 and are jointly arranged in the stainless steel tube 2. The upper lead rod 19 is riveted to connect the power line 12 and the NTC connecting line 13. The power line 12 and the NTC connecting line 13 are led out of the stainless steel tube 2, and the pipe mouth is sealed by epoxy resin glue 11. The thermal fuse 3 and the NTC temperature probe 4 with riveted terminals are respectively welded to the welded lower lead rod 18, and then pierced with a plurality of four-hole magnesium oxide rods 21. The parts of the thermal fuse 3 and the NTC temperature probe 4 exposed outside the magnesium oxide rod are insulated from the appearance by a heat shrink sheath 20, and the remaining space in the stainless steel tube 2 is filled with magnesium oxide powder 6.

[0037] Example 1

[0038] like Figure 2A single-head electric heating tube structure with a built-in temperature probe comprises a stainless steel tube 2 after a diameter reduction treatment, a bottom cover 1 is provided at one end of the stainless steel tube 2, and a flange 10 is provided on the outside of the other end. An upper lead rod 19 and a lower lead rod 18 are connected by welding through a resistance wire 7 and are arranged together in the stainless steel tube 2. The upper lead rod 19 is welded to one end of a power line 12 and an NTC connecting line 13, and the other ends of the power line 12 and the NTC connecting line 13 are connected to the pins of a quick-connect plug 14. Five pins of the quick-connect plug 14 lead out of the stainless steel tube 2. A grounding wire 9 is provided on the tube mouth and is sealed by an epoxy resin glue 11. The tube body is filled with magnesium oxide powder.

[0039] The thermal fuse 3 and the NTC temperature probe 4 with riveted terminals are welded to the welded lower lead rods respectively, and then installed in the PE centering ring 16 and the PE sheath 15. There are 4 lower lead rods 18. There are four lower lead rods, two of which are welded to the two ends of the thermal fuse 3 respectively to form a U-shaped loop; the other two are welded to the two ends of the NTC temperature probe 4 to form another U-shaped loop, and the two U-shaped loops are arranged in the PE sheath 15, in parallel with each other and not in contact with each other; the PE sheath 15 is a pipe sleeve structure with one end open, and the PE centering ring 16 includes a collar, which is installed in the open end of the PE sheath 15, and four pipe sleeves with parallel axes are jointly arranged in the collar, and the middle parts of the four lower lead rods 18 are respectively sleeved in the four pipe sleeves. The lower lead rods 18 outside the sleeve are also sleeved with fragile steatite porcelain fixing beads 17, which are used to ensure the spacing between the lower lead rods 18 and between the lower lead rods 18 and the pipe wall to ensure the electrical performance of the product. The inner wall of the opening end of the PE sheath 15 is provided with a groove, and the PE centering ring 16 is trumpet-shaped and has a step structure on the outside, which can match the groove of the PE sheath 15. The four pipe sleeves in the PE centering ring 16 are arranged in a cross shape and have different lengths to avoid the gap between the four guide rods being too small due to welding points. The outer diameter of the PE sheath 15 is smaller than the inner diameter of the stainless steel pipe 2 after the diameter reduction. A grounding wire 9 is also connected to the electric heating pipe.

[0040] The NTC temperature probe 4 in the present invention is a thermistor. A commonly used commercial product can be used. The automatic powder filling machine used in conjunction with the device of the present invention can be a product of the 1CTDZ310Q series, 1CTDZ406Q series, 1CTDZ709Q series, 1CTDZ729Q series, 1CTDZ845Q series, 1CTDZ900Q series, 1CTDZ951Q series, 1CTDZ956Q series produced by Hangzhou Zoppas Industrial Co., Ltd.

[0041] The present invention also provides a method for manufacturing the above-mentioned single-head electric heating tube structure, the steps are:

[0042] (1) The joints of the thermal fuse 3 and the NTC temperature probe 4 are first riveted onto the upper terminal 5, and then respectively welded to the four lower lead rods 18, and then the thermal fuse 3, the NTC temperature probe 4 and the welded lower lead rods 18 are installed into the PE centering ring 16 and the PE sheath 15;

[0043] (2) One end of the resistance wire 7 is welded to the upper lead rod 19, and the other end is welded to the lower lead rod 18. Then, the assembly is hung on the automatic powder filling machine through the hook on the upper lead rod 19, and the stainless steel tube 2 with the bottom cover 1 welded is put on to fill the magnesium oxide powder 6;

[0044] (3) After filling with powder, the pipe mouth is sealed with a silicone plug 8, and then the stainless steel pipe 2 is reduced in diameter with a tube shrinking machine. Then, the power line 12 and the NTC connecting line 13 are welded to the exposed upper guide rod 19, and finally, the flange 10 is riveted and sealed with epoxy resin glue 11.

[0045] Finally, it should be noted that the above examples are only specific embodiments of the present invention. Obviously, the present invention is not limited to the above examples, and many variations are possible. All variations that can be directly derived or associated with the content disclosed by a person skilled in the art should be considered as the protection scope of the present invention.

Claims

1. A single-head electric heating tube structure with a built-in temperature probe, comprising a stainless steel tube after diameter reduction treatment, a bottom cover is provided at one end of the tube body, a flange is provided on the outside of the other end, and a sealing material is provided at the flange end of the tube; a resistance wire is provided in the tube body and filled with magnesium oxide powder, the two ends of the resistance wire are respectively connected to an upper lead rod and a lower lead rod, the lower lead rod is connected to a thermal fuse and an NTC temperature probe, the upper lead rod is connected to a power line and one end of an NTC connecting line, and the other end of the power line and the NTC connecting line extends out of the tube; characterized in that It also includes a PE sheath and a PE centering ring; there are four lower lead rods, two of which are respectively welded to the two ends of the thermal fuse to form a U-shaped loop; the other two are welded to the two ends of the NTC temperature probe to form another U-shaped loop, and the two U-shaped loops are arranged in the PE sheath, connected in parallel and not in contact with each other; the PE sheath is a pipe sleeve structure with one end open, and the PE centering ring includes a sleeve ring, which is installed in the open end of the PE sheath, and four pipe sleeves with parallel axes are jointly arranged in the sleeve ring, and the middle parts of the four lower lead rods are respectively sleeved in the four pipe sleeves; The diameter of the PE centering ring is larger than the inner diameter of the stainless steel pipe after the diameter reduction treatment; the outer diameter of the PE sheath is smaller than the inner diameter of the stainless steel pipe after the diameter reduction treatment; A groove is provided on the inner wall of the pipe opening at the open end of the PE sheath; the PE centering ring is trumpet-shaped and has a step structure on the outside, and the step structure can cooperate with the groove of the PE sheath pipe opening; the four pipe sleeves in the PE centering ring are arranged in a cross shape and have different lengths to avoid the gap between the four guide rods being too small due to the presence of welding points.

2. The single-head electric heating tube structure with a built-in temperature probe according to claim 1, characterized in that: The thermal fuse and the NTC temperature probe are connected to the lower lead rod through terminal welding.

3. The single-head electric heating tube structure with a built-in temperature probe according to claim 1, characterized in that: The portion of the lower guide rod passing through the tube sleeve is also sleeved with fragile steatite fixing beads, which are used to ensure that there is a distance between the lower guide rods and between the lower guide rods and the tube wall.

4. The single-head electric heating tube structure with a built-in temperature probe according to claim 1, characterized in that: The power line and the connecting line extend out of the stainless steel tube and are connected with quick-connect plugs; the single-head electric heating tube structure is also provided with a grounding wire.

5. A method for manufacturing the single-end electric heating tube structure according to any one of claims 1 to 4, characterized in that: The specific steps of this method are: (1) The joints of the thermal fuse and the NTC temperature probe are first riveted onto the terminals, then welded to the four lower lead rods respectively, and then the thermal fuse and the NTC temperature probe are installed into the PE centering ring and the PE sheath; (2) One end of the resistance wire is welded to the upper lead rod, and the other end is welded to the lower lead rod. Then the assembly is hung on the automatic powder filling machine through the hook on the upper lead rod, and the stainless steel tube with the welded bottom cover is put on to fill the magnesium oxide powder; (3) After filling the powder, seal the pipe mouth with a silicone plug, and then use a tube shrinking machine to reduce the diameter of the pipe body. Then weld the power line and NTC connecting line to the exposed upper guide rod, and finally rivet the flange and seal it with sealing material.

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