Exhaust pipe adopting brazing furnace to weld copper pipe and manufacturing process of exhaust pipe

Abstract

An exhaust pipe manufacturing process adopting a brazing furnace to weld a copper pipe comprises the following steps that S1, the copper pipe is manufactured; s2 and S3, a stainless steel pipe with a seat ring is manufactured; s4, the copper pipe obtained in the step S2 is pressed into the upper end hole of the stainless steel pipe obtained in the step S3, and a proper welding gap is formed between the outer diameter of the copper pipe and the inner diameter of the upper end hole; and S5, the outer diameter of the opening of the copper pipe is sleeved with a welding ring, the welding ring is pressed to the end face of the stainless steel pipe, the welding ring is tightly attached to the position needing to be welded, then welding forming is conducted through a brazing furnace, and the exhaust pipe is obtained. An exhaust pipe adopting a brazing furnace to weld a copper pipe comprises a stainless steel pipe 1, a seat ring 2 is connected to the outer side of the middle of the stainless steel pipe 1, and an upper end hole 3 is formed in the upper end of the stainless steel pipe 1. And a copper pipe 4 is welded in the upper end hole 3 through a brazing furnace. A new structure of the exhaust pipe is redesigned, so that existing flame welding can be replaced by brazing furnace welding, the step of acid pickling is omitted, and the environmental protection property is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of exhaust pipe technology, specifically to an exhaust pipe using a brazing furnace to weld copper pipes and its manufacturing process. Background Technology

[0002] Existing exhaust pipes generally consist of a copper pipe and a seat ring. The seat ring is press-fitted onto the copper pipe, and a welding ring is then fitted onto it. The pipes are then flame-welded together. After welding, acid pickling is required, followed by cleaning and polishing to obtain the exhaust pipe (see attached instruction manual). Figure 1 This manufacturing process has the following disadvantages:

[0003] 1. Flame welding produces toxic and harmful substances such as carbon monoxide and metal fumes, which can easily lead to safety accidents and is not environmentally friendly;

[0004] 2. The high temperature of the flame during flame welding can easily cause burns, and the intense light produced can easily damage the eyes;

[0005] 3. Flame welding also carries risks such as welding torch backfire and abnormal gas cylinder pressure;

[0006] 4. After flame welding, the product needs to be pickled, which affects the environment;

[0007] 5. Because the existing exhaust pipes are mainly made of copper, the amount of copper used is large, and the cost is relatively high. Summary of the Invention

[0008] The present invention aims to solve the above-mentioned technical problems by providing an exhaust pipe and its manufacturing process using a brazing furnace to weld copper tubes.

[0009] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0010] A process for manufacturing an exhaust pipe using a brazing furnace to weld copper tubes includes the following steps:

[0011] S1. Place the copper tube material onto the automatic cutting machine, which will cut it to obtain a copper tube semi-finished product of the required size. Then, punch a bevel on the copper tube semi-finished product. After punching the bevel, the copper tube semi-finished product will be degreased and rough and fine polished to obtain the required copper tube.

[0012] S2. The stainless steel bar is straightened and surface-treated and lubricated by an automatic feeder. It is then automatically cut to a fixed length according to the product size to form a billet. It is then fed into a cold heading machine for pre-heading to form the head contour of the billet. Finally, it is head-headed to form the overall shape and structure of the billet. A ring is formed on the outside of the billet. Then, the head of the billet is punched to form the upper hole for the fitting clearance required for assembling copper tubes and welding. Finally, the billet with the head punched is punched a second time to form a through hole in the middle.

[0013] S3. After the blank is punched twice in step S2, it is machined to meet the required dimensions, roundness and roughness. Then it is degreased and rough and fine polished to obtain a stainless steel tube with a seat ring.

[0014] S4, press the copper tube obtained in step S1 into the upper hole of the stainless steel tube obtained in step S3, so that the copper tube does not loosen or fall off, and a suitable welding gap is formed between the outer diameter of the copper tube and the inner diameter of the upper hole.

[0015] S5. Insert the welding ring onto the outer diameter of the copper pipe opening and press the welding ring against the end face of the stainless steel pipe. The welding ring is tightly attached to the required welding position. Then, it is welded in a brazing furnace to form the exhaust pipe.

[0016] In step S1, the copper tube semi-finished product after the bevel is first placed in a turnover frame, and then immersed in an oil removal tank through the turnover frame. The temperature of the oil removal tank is controlled above 85°C, and the soaking time is more than 1 minute. After being taken out, it is rinsed in a three-stage water tank, and finally placed in a spiral vibrating machine for grinding and polishing for about 30 minutes to obtain the required copper tube.

[0017] The copper tube has a wall thickness of 0.4 mm.

[0018] In step S3, the machined blank is first placed in a turnover frame, and then immersed in an oil removal tank through the turnover frame. The temperature of the oil removal tank is controlled above 85°C, and the soaking time is more than 1 minute. After being taken out, it is rinsed in a three-stage water tank, and finally placed in a spiral vibrating machine for grinding and polishing for about 30 minutes to obtain a stainless steel tube with a seat ring.

[0019] In step S1, the copper tube semi-finished product is punched at an angle using an open inclinable press.

[0020] When the S5 step involves welding in a brazing furnace, the brazing furnace must first be adjusted to a suitable welding temperature, mesh speed, shielding gas flow rate, and cooling water flow rate. After the welded product is placed in the welding fixture and fixed, it is then placed on the mesh belt. The welded product enters the brazing furnace with the mesh belt, passing through the preheating zone, high-temperature welding zone, and cooling zone before finally exiting the furnace, thus completing the product welding.

[0021] It also includes the following steps:

[0022] S6. The exhaust pipes obtained in step S5 are screened and packaged. Check whether the weld seam on the front side of the exhaust pipe and the bottom of the copper pipe have flowed out. Check the surface quality and appearance quality of the weld seam. Package the pipes only after they pass the inspection.

[0023] An exhaust pipe using a brazing furnace to weld copper tubes, manufactured using the aforementioned manufacturing process for an exhaust pipe using a brazing furnace to weld copper tubes, includes a stainless steel tube; a seat ring is connected to the outer side of the middle part of the stainless steel tube, and an upper end hole is opened at the upper end of the stainless steel tube; a copper tube is welded through the upper end hole using a brazing furnace.

[0024] The technical effects that this invention can achieve are:

[0025] 1. The present invention redesigns the structure of the exhaust pipe, so it can be welded in a brazing furnace instead of the existing flame welding, eliminating the pickling step and avoiding the emission of toxic and harmful gases generated by pickling, thus significantly improving environmental protection.

[0026] 2. This invention uses stainless steel pipe as the main body, and the thickness of the copper pipe material is reduced to 0.4mm and the length is shortened, directly reducing the amount of copper used by 95% and reducing the cost of copper by nearly 90%; while the price of stainless steel is much lower than that of copper, its material cost is significantly reduced.

[0027] 3. The brazing furnace heats the surface evenly, resulting in a clean surface after welding (no weld beads or oxide layer), more uniform stress at the copper-iron joint, and a lower defect rate.

[0028] 4. This invention uses stainless steel pipe as the main body, which is more durable, less prone to corrosion, and has a longer service life;

[0029] 5. Copper has low deformation resistance, so it does not require multiple stretching and intermediate annealing, which improves the efficiency of single-pass stretching and increases material utilization. In addition, when cutting copper tubes, the thinner copper tube can reduce blade wear. Attached Figure Description

[0030] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0031] Figure 1 This is a schematic diagram of the existing exhaust pipe structure;

[0032] Figure 2 This is a schematic diagram of the structure of the billet after pre-upsetting;

[0033] Figure 3 This is a schematic diagram of the structure of the billet after final upsetting;

[0034] Figure 4 This is a schematic diagram of the structure of the blank after the first punching;

[0035] Figure 5 This is a schematic diagram of the structure of the blank after the second punching;

[0036] Figure 6 This is a schematic diagram of the structure of an exhaust pipe for welding copper pipes using a brazing furnace according to the present invention. Detailed Implementation

[0037] The invention will now be described in further detail with reference to the accompanying drawings.

[0038] See Figures 1 to 6 .

[0039] A process for manufacturing an exhaust pipe using a brazing furnace to weld copper tubes includes the following steps:

[0040] S1. The copper tube material is placed on an automatic cutting machine, which cuts it to obtain a semi-finished copper tube of the required size. The semi-finished copper tube is then beveled. Specifically, the semi-finished copper tube is beveled using an open-type inclinable press. After beveling, the semi-finished copper tube is degreased and rough and fine polished to obtain the required copper tube with a wall thickness of 0.4mm. In the specific operation of degreasing and rough and fine polishing of the semi-finished copper tube, the beveled copper tube is first placed in a turnover frame, and then immersed in a degreasing tank. The temperature of the degreasing tank is controlled above 85℃, and the immersion time is more than 1 minute. After being taken out, it is rinsed in a three-stage water tank, and finally placed in a spiral vibrating machine for grinding and polishing for about 30 minutes to obtain the required copper tube.

[0041] S2, the stainless steel bar is straightened and surface-treated with lubrication by an automatic feeder, and then automatically cut to a fixed length according to the product dimensions to form a billet. This billet is then fed into a cold heading machine for pre-heading, which shapes the head profile of the billet (see reference). Figure 2 Then, the final upsetting is performed to shape the overall shape and structure of the billet (see reference). Figure 3 A ring is formed on the outside of the billet, and then a hole is punched at the head of the billet (see reference). Figure 4 This creates the upper hole required for the fitting clearance size of the copper tubes during assembly and welding. Finally, the blank with the hole punched at the head is punched a second time, creating a through hole in the center (see reference). Figure 5 );

[0042] S3. After the blank is punched twice in step S2, it is machined to achieve the required dimensions, roundness, and roughness. Then, it is degreased and rough and fine polished to obtain a stainless steel tube with a seat ring. Specifically, the machined blank is first placed in a turnover frame, and then immersed in a degreasing tank through the turnover frame. The temperature of the degreasing tank is controlled above 85℃, and the immersion time is more than 1 minute. After being taken out, it is rinsed in a three-stage water tank. Finally, it is placed in a spiral vibrating machine for grinding and polishing for about 30 minutes to obtain a stainless steel tube with a seat ring.

[0043] S4, press the copper tube obtained in step S1 into the upper hole of the stainless steel tube obtained in step S3, so that the copper tube does not loosen or fall off, and a suitable welding gap is formed between the outer diameter of the copper tube and the inner diameter of the upper hole.

[0044] S5. Insert the welding ring onto the outer diameter of the copper pipe opening and press the welding ring against the end face of the stainless steel pipe. The welding ring should be tightly attached to the desired welding position. Then, weld it through a brazing furnace to obtain the exhaust pipe. In the specific welding process, the brazing furnace should first be adjusted to the appropriate welding temperature, mesh speed, shielding gas flow rate, and cooling water flow rate. After the product to be welded is placed in the welding fixture and fixed, it is then placed on the mesh belt. The product to be welded enters the brazing furnace with the mesh belt, passing through the preheating zone, the high-temperature welding zone, and the cooling zone. Finally, it exits the furnace, thus completing the product welding and obtaining the exhaust pipe.

[0045] S6. The exhaust pipes obtained in step S5 are screened and packaged. Check whether the weld seam on the front side of the exhaust pipe and the bottom of the copper pipe have flowed out. Check the surface quality and appearance quality of the weld seam. Package the pipes only after they pass the inspection.

[0046] An exhaust pipe using a brazing furnace to weld copper tubes, manufactured using the aforementioned manufacturing process for an exhaust pipe using a brazing furnace to weld copper tubes, includes a stainless steel tube 1, a seat ring 2 connected to the outer side of the middle part of the stainless steel tube 1, and an upper end hole 3 opened at the upper end of the stainless steel tube 1; a copper tube 4 is welded through the upper end hole 3 using a brazing furnace.

[0047] This invention redesigns the exhaust pipe structure, using a stainless steel pipe 1 as the main body, with a copper pipe 4 welded into the upper end hole 3 of the stainless steel pipe 1. This reduces the wall thickness of the copper pipe 4 to only 0.4mm and significantly shortens its length, reducing the amount of copper used by about 95%. Since the price of stainless steel is much lower than that of copper, the overall product cost is significantly reduced. Furthermore, the corrosion resistance of stainless steel greatly increases its service life. During the manufacturing process of the copper pipe 4, the low deformation resistance of copper eliminates the need for multiple stretching and intermediate annealing processes, improving the efficiency of single-pass stretching. Moreover, because the copper pipe 4 has a thinner wall, the wear of the cutting blade can be effectively reduced during cutting.

[0048] In the welding process between stainless steel pipe 1 and copper pipe 4, this invention uses a brazing furnace for welding, thus eliminating the need for a pickling process after flame welding. This reduces acid pollution and avoids the emission of harmful gases generated during pickling, while also accelerating product manufacturing efficiency, significantly improving the environmental friendliness of this invention. In terms of yield, because this invention uses a brazing furnace for welding, compared to existing flame welding, the heating in the brazing furnace is more uniform, resulting in a cleaner surface after welding (no weld beads or oxide layer). The stress at the joint is also more uniform, significantly improving the yield. Furthermore, this invention uses a brazing furnace for welding, which, compared to flame welding, avoids problems such as eye damage and flame burns to employees, ensuring their personal safety.

Claims

1. A manufacturing process for an exhaust pipe using a brazing furnace to weld copper tubes, characterized in that, Includes the following steps: S1. Place the copper tube material onto the automatic cutting machine, which will cut it to obtain a copper tube semi-finished product of the required size. Then, punch a bevel on the copper tube semi-finished product. After punching the bevel, the copper tube semi-finished product will be degreased and rough and fine polished to obtain the required copper tube. S2. The stainless steel bar is straightened and surface-treated and lubricated by an automatic feeder. It is then automatically cut to a fixed length according to the product size to form a billet. It is then fed into a cold heading machine for pre-heading to form the head contour of the billet. Finally, it is head-headed to form the overall shape and structure of the billet. A ring is formed on the outside of the billet. Then, the head of the billet is punched to form the upper hole for the fitting clearance required for assembling copper tubes and welding. Finally, the billet with the head punched is punched a second time to form a through hole in the middle. S3. After the blank is punched twice in step S2, it is machined to meet the required dimensions, roundness and roughness. Then it is degreased and rough and fine polished to obtain a stainless steel tube with a seat ring. S4, press the copper tube obtained in step S1 into the upper hole of the stainless steel tube obtained in step S3, so that the copper tube does not loosen or fall off, and a suitable welding gap is formed between the outer diameter of the copper tube and the inner diameter of the upper hole. S5. Insert the welding ring onto the outer diameter of the copper pipe opening and press the welding ring against the end face of the stainless steel pipe. The welding ring is tightly attached to the required welding position. Then, it is welded in a brazing furnace to form the exhaust pipe.

2. The exhaust pipe manufacturing process using a brazing furnace to weld copper pipes according to claim 1, characterized in that: In step S1, the copper tube semi-finished product after the bevel is first placed in a turnover frame, and then immersed in an oil removal tank through the turnover frame. The temperature of the oil removal tank is controlled above 85°C, and the soaking time is more than 1 minute. After being taken out, it is rinsed in a three-stage water tank, and finally placed in a spiral vibrating machine for grinding and polishing for about 30 minutes to obtain the required copper tube.

3. A manufacturing process for an exhaust pipe using a brazing furnace to weld copper pipes according to claim 1 or 2, characterized in that: The copper tube has a wall thickness of 0.4 mm.

4. The exhaust pipe manufacturing process using a brazing furnace to weld copper pipes according to claim 1, characterized in that: In step S3, the machined blank is first placed in a turnover frame, and then immersed in an oil removal tank through the turnover frame. The temperature of the oil removal tank is controlled above 85°C, and the soaking time is more than 1 minute. After being taken out, it is rinsed in a three-stage water tank, and finally placed in a spiral vibrating machine for grinding and polishing for about 30 minutes to obtain a stainless steel tube with a seat ring.

5. The exhaust pipe manufacturing process using a brazing furnace to weld copper pipes according to claim 1, characterized in that: In step S1, the copper tube semi-finished product is punched at an angle using an open inclinable press.

6. The manufacturing process for an exhaust pipe using a brazing furnace to weld copper pipes according to claim 1, characterized in that: When the S5 step involves welding in a brazing furnace, the brazing furnace must first be adjusted to a suitable welding temperature, mesh speed, shielding gas flow rate, and cooling water flow rate. After the welded product is placed in the welding fixture and fixed, it is then placed on the mesh belt. The welded product enters the brazing furnace with the mesh belt, passing through the preheating zone, high-temperature welding zone, and cooling zone before finally exiting the furnace, thus completing the product welding.

7. The manufacturing process for an exhaust pipe using a brazing furnace to weld copper pipes according to claim 1, characterized in that... It also includes the following steps: S6. The exhaust pipes obtained in step S5 are screened and packaged. Check whether the weld seam on the front side of the exhaust pipe and the bottom of the copper pipe have flowed out. Check the surface quality and appearance quality of the weld seam. Package the pipes only after they pass the inspection.

8. An exhaust pipe for welding copper tubes using a brazing furnace, characterized in that: The exhaust pipe is manufactured using the brazing furnace welding copper pipe manufacturing process described in any one of claims 1 to 7, comprising a stainless steel pipe (1); a seat ring (2) is connected to the outer side of the middle part of the stainless steel pipe (1), and an upper end hole (3) is opened at the upper end of the stainless steel pipe (1); a copper pipe (4) is welded through the brazing furnace in the upper end hole (3).

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