Finished thin-walled tube heat treatment and hot straightening device

Abstract

The utility model belongs to the technical field of metal material processing, and particularly relates to a finished thin-walled tube heat treatment and hot straightening device which comprises a heating furnace chamber, a heat treatment chamber is arranged in the heating furnace chamber, a heat treatment cavity is arranged in the heat treatment chamber, an annular groove is formed in the inner wall of the heat treatment cavity, and a metal ring is arranged in the annular groove. The metal ring sleeves the outer side of the thin-walled tube and is fixed through the first fixing piece; the transmission assembly drives the heat treatment furnace chamber to rotate; and along with the rotation of the heat treatment furnace chamber, the metal ring on the outer side of the thin-walled pipe rolls along the annular groove. According to the device, the problems of poor straightness and roundness caused by uneven stress release during and after heat treatment of the thin-walled tube can be reduced by means of the self weight of the thin-walled tube and the weight of the counter weight, the thin-walled tube with poor straightness and roundness is straightened, the straightness and roundness are improved, and the device is simple in structure, can be repeatedly used, and is suitable for popularization and application. Various molds are not needed, and the cost is low.

Description

Technical Field

[0001] The utility model belongs to the technical field of metal material processing, and particularly relates to a device for heat treatment and hot straightening of finished thin-walled tubes. Background Art

[0002] In industrial production, for cold-formed metal thin-walled pipe fittings (wall thickness 0.5 - 1.0 mm) such as cold-rolled thin-walled pipes and cold-spun thin-walled pipes, due to the thin wall thickness, the final size of the cold deformation of the pipe fittings is often the use size or assembly size, without the allowance for secondary processing. Therefore, the finished pipe needs to have a very high straightness and roundness to meet the use requirements.

[0003] After the forming process of cold-formed metal thin-walled pipes, the pipes often need to be annealed to relieve stress and homogenize the structure, reducing the anisotropy of the pipe body. For finished thin-walled pipes, their wall thickness is very limited, and during heat treatment, due to uneven stress release or uneven heating, deformation is likely to occur. Currently, several common heat treatment methods all have drawbacks: (1) During heat treatment, when the thin-walled pipe is placed flat on the furnace bottom plate of the heat treatment furnace, the heat received by the side of the pipe body close to the furnace bottom plate is often higher than the heat received by other positions of the pipe wall due to radiation, resulting in uneven heating of the pipe body, uneven tissue change and stress release, and macroscopically leading to or exacerbating the deformation of the thin-walled pipe. (2) If the pipe body is placed on a support during heat treatment, the support provides several support points for the pipe body, and the support is placed on the furnace bottom plate, then contact between the pipe body and the furnace bottom plate can be avoided. However, the contact area between the support point of the support and the pipe body cannot be too large, otherwise it is similar to the situation of contacting the furnace bottom plate; in this case, the cross-sectional size of the contact position of the support is limited, and it is difficult to maintain the strength at high temperature, that is, the support is prone to deformation during heat treatment, and the flatness of the bearing surface of the pipe body cannot be controlled. If the support deforms, the pipe body is more likely to deform; at the same time, the pipe body outside the support points of the support is in a suspended state, and during the heating process, it is more likely to bend due to the action of gravity. (3) If the thin-walled pipe is vertically suspended in a pit furnace, if the temperature uniformity of the furnace chamber is good, the uneven heating of the pipe body can be reduced, avoiding the first two situations. However, it is often necessary to reserve a part for hanging the pipe body. For firm fixation, holes need to be drilled in the pipe body, and after heat treatment, the drilled section needs to be machined off. For materials with high value such as titanium and zirconium, the production cost will increase. (4) Avoiding oxidation is also a very important requirement for the heat treatment of thin-walled pipes. The heat treatment of thin-walled pipes is different from that of thick-walled pipes. Before heat treatment of thick-walled pipes, machining allowance can be reserved. At the same time, due to the thick wall thickness, if the straightness of the pipe body itself is very good, the stress release during heat treatment is difficult to affect the overall straightness of the pipe fitting. After heat treatment, the surface oxidation can be removed through machining, and at the same time, the finished size can be obtained. However, for finished thin-walled pipes, the wall thickness is very thin. If oxidation occurs during heat treatment, it is very difficult to deal with the oxidation problem through machining. When the machining tool is close to the pipe body, the pipe body will deform, and the machining difficulty is extremely high, and it is very difficult to ensure the wall thickness uniformity and roundness of the finished product.

[0004] At the same time, for thin-walled tubes with poor straightness and roundness, cold straightening often causes pipe rupture due to limited wall thickness, so hot straightening is mainly used. Existing thin-walled tube straightening devices mostly use rollers with holes to straighten heated pipes, but due to the influence of factors such as pipe wall thickness and diameter, the effect is often unsatisfactory; at the same time, it is easy to cause oxidation of pipes that are already finished specifications, and they cannot meet the use requirements after straightening. Patent CN202893900U discloses a straightening device for thin-walled pipes, and its specific method is to pass the thin-walled pipe to be straightened through a hole formed by three straightening rollers arranged in a triangle, and use three straightening rollers to rotate and roll to straighten the thin-walled pipe. When straightening with this scheme, the pipe body is subjected to the pressure of the straightening rollers. Since the pipe wall is very thin, the pipe body is easily deformed under pressure, resulting in substandard size of the finished pipe. Patent CN211938489U discloses a thin-walled steel pipe straightening machine, which mainly solves the problem that after the thin-walled pipe fittings come out of the straightening machine, when the pipe fittings are supported by the pipe fittings at both ends of the pipe fittings, the pipe fittings are bent under the action of gravity due to the lack of support in the middle. The straightening effect of the straightening machine itself is not disclosed. Patent CN202020274729.9 discloses a flexible fully automatic straightening device for large-diameter thin-walled seamless steel pipes. The specific method is that the pipe to be straightened is pulled by a telescopic rod and repeatedly passes through a heated circular pipe seat. The pipe to be straightened is heated and then repeatedly passes through a circular groove, and the circular groove is used to straighten some of the bent parts. In this straightening scheme, the pipe to be straightened will repeatedly rub against the inside of the circular groove, damaging the outer surface of the pipe body, and the relative movement process between the circular groove and the pipe to be straightened is equivalent to an extrusion process, which may cause the size of the pipe body to change. At the same time, none of the above straightening schemes can guarantee a vacuum environment, and straightening operations cannot be performed on thin-walled pipes without processing allowances. Utility Model Content

[0005] The utility model provides a device for heat treatment and heat straightening of finished thin-walled tubes to solve the problems of poor straightness and roundness of finished tubes caused by the above two situations, which are:

[0006] (1) Some cold-formed alloy tubes such as cold-rolled thin-walled tubes and cold-spun thin-walled tubes have very thin walls and no or very limited machining allowances, but poor straightness and require straightening operations, which are insufficient in existing technology.

[0007] (2) After the cold-formed thin-walled tube forming process is completed, the tube often needs to be annealed to relieve stress and homogenize the structure to reduce the anisotropy of the tube body. For the finished thin-walled tube, the wall thickness is very thin, and the stress release during heat treatment is more uneven, and the tube body may bend.

[0008] The utility model is specifically realized through the following technical solutions.

[0009] An apparatus for heat treatment and hot straightening of a finished thin-walled tube, comprising:

[0010] A heating furnace chamber, the inner wall of the heating furnace chamber being provided with heating elements;

[0011] A heat treatment furnace chamber, disposed within the heating furnace chamber, the heat treatment furnace chamber being provided with a heat treatment cavity, the thin-walled tube being disposed within the heat treatment cavity, a plurality of metal rings being sleeved outside the thin-walled tube, and the metal rings being fixed to the outside of the thin-walled tube by first fixing members; a plurality of annular grooves are circumferentially formed on the inner wall of the heat treatment cavity, the annular grooves being matched with the metal rings, and the metal rings being capable of rolling along the annular grooves;

[0012] A transmission assembly, disposed outside the heating furnace chamber, the output end of the transmission assembly passing through the heating furnace chamber and being fixedly connected to one end of the heat treatment furnace chamber for driving the heat treatment furnace chamber to rotate;

[0013] As the heat treatment furnace chamber rotates, the metal rings outside the thin-walled tube roll along the annular grooves.

[0014] In a preferred embodiment, when the metal rings roll, there is a fitting surface between the surface of the thin-walled tube and the inner wall of the heat treatment cavity. It should be noted that the apparatus for heat treatment and hot straightening of the finished thin-walled tube provided by the present utility model has the following two functions: The first is to prevent the thin-walled tube with good straightness from being bent during heat treatment, that is, its heat treatment function; the second is to straighten the thin-walled tube with poor original straightness during heat treatment, that is, its hot straightening function. The specific function of this fitting is that when the thin-walled tube rolls while fitting the inner wall of the heat treatment cavity, at any moment, the force on the thin-walled tube along its length is uniform, and at any moment, the supporting force received by the thin-walled tube is evenly distributed on the line where it fits the inner wall of the heat treatment cavity, so it will not be bent due to gravity. If the thin-walled tube does not fit the inner wall of the heat treatment cavity when it rolls, at any moment, the supporting force received by the thin-walled tube only comes from the supporting points of the metal rings. Except for these supporting points, the rest of the thin-walled tube is in a suspended state. For a very long thin-walled tube, under the action of heat, the material resistance of the thin-walled tube itself decreases, and under the action of gravity, the suspended positions may collapse, causing the thin-walled tube to bend.

[0015] In a preferred embodiment, a plurality of metal rings are evenly sleeved outside the thin-walled tube, and the center of each metal ring is located on the axis of the thin-walled tube.

[0016] In a preferred embodiment, the fixing member is a screw rod. A plurality of threaded round holes are radially formed in the metal ring, and each round hole is internally threaded with the first fixing member. The plurality of first fixing members cooperate to fix the center of the metal ring on the axis of the thin-walled tube. It should be noted that a set of metal rings and first fixing members can fix thin-walled tubes of various diameters. When the diameter of the thin-walled tube changes, only the position of the first fixing member relative to the round hole needs to be adjusted radially so that the center of the metal ring is located on the axis of the thin-walled tube.

[0017] In a preferred embodiment, the heat treatment furnace chamber includes a heat treatment furnace chamber box body and a heat treatment furnace chamber cover plate, which are hermetically fixed with each other by a second fixing member. The heat treatment chamber is arranged inside the heat treatment furnace chamber box body. An air inlet hole and an air outlet hole are arranged outside the heat treatment furnace chamber cover plate. The air inlet hole and the air outlet hole are communicated with the heat treatment chamber, and air stop valves are arranged on both the air inlet hole and the air outlet hole.

[0018] In a preferred embodiment, a plurality of heat treatment chambers are formed inside the heat treatment furnace chamber box body, and each heat treatment chamber is provided with a thin-walled tube.

[0019] In a preferred embodiment, the heating furnace chamber includes a heating furnace chamber box body and a heating furnace chamber cover plate. The heating element is a resistance wire. A heat preservation layer is arranged on the inner wall of the heating furnace chamber box body, and a resistance wire is arranged inside the heat preservation layer. The heating furnace chamber box body and the heating furnace chamber cover plate are fixed with each other by a third fixing member.

[0020] In a preferred embodiment, rollers are arranged at the bottom of the inner wall of the heating furnace chamber box body, and the bottom of the heat treatment furnace chamber box body abuts against the surface of the rollers.

[0021] In a preferred embodiment, the transmission assembly includes a first transmission gear, a second transmission gear and a motor. The output end of the motor is fixedly connected with the first transmission gear. The first transmission gear is meshed with the second transmission gear. The rotating shaft of the second transmission gear passes through the heating furnace chamber box body and is fixedly connected with one end of the heat treatment furnace chamber box body away from the heat treatment furnace chamber cover plate.

[0022] In a preferred embodiment, the heating furnace chamber is placed on a furnace body support, and the motor is placed on a motor support.

[0023] The utility model has the following beneficial effects compared with the prior art:

[0024] 1. In the utility model, the heat treatment furnace chamber is powered by the transmission assembly to rotate in the heating furnace chamber. The heat-treated thin-walled tube rotates and revolves along the inner wall of the heat treatment furnace chamber as the heat treatment furnace chamber rotates. The metal ring provides the thin-walled tube with fixation, counterweight and rolling guidance. This device can rely on the deadweight of the thin-walled tube and the weight of the counterweight of the metal ring to reduce the deformation problem caused by uneven stress release during and after the heat treatment of the thin-walled tube with good straightness, and straighten the thin-walled tube with poor straightness to improve the straightness;

[0025] 2. The device has a simple structure and is suitable for finished thin-walled tubes of various diameters. It does not require the preparation of various molds and has low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of the overall connection structure of a device for heat treatment and heat straightening of a finished thin-walled tube provided by the utility model;

[0027] Figure 2 A schematic diagram of the cross-sectional structure of a device for heat treatment and heat straightening of a finished thin-walled tube provided by the utility model Figure 1 ;

[0028] Figure 3 A schematic diagram of the cross-sectional structure of a device for heat treatment and heat straightening of a finished thin-walled tube provided by the utility model Figure 2 ;

[0029] Figure 4 Schematic diagram of the annular groove structure;

[0030] Figure 5 It is a schematic diagram of the cross-sectional structure of the heating furnace chamber;

[0031] Figure 6 It is a schematic diagram of the connection relationship between the metal ring and the fixing part;

[0032] Figure 7 for Figure 6 Side view of the structure;

[0033] Figure 8 It is a schematic diagram of the surface structure of the heat treatment furnace chamber cover;

[0034] Figure 9 for Figure 8 Side view of the structure;

[0035] Figure 10 This is a schematic diagram of a heat treatment furnace chamber box for treating multiple roots in one furnace;

[0036] Figure 11 for Figure 10 Enlarged view of point A in the middle.

[0037] Description of reference numerals:

[0038] 1. First driving gear, 2. Second driving gear, 3. First bolt, 4. Nut, 5. Second bolt, 6. Thin-walled tube, 7. First fixing piece, 8. Metal ring, 9. Heat treatment furnace chamber box body, 9-1. Heat treatment cavity, 9-2. Annular groove, 10. Air inlet hole, 11. Exhaust hole, 12. Heat treatment furnace chamber cover plate, 13. Roller, 14. Heating furnace chamber box body, 15. Heating furnace chamber cover plate, 16. Heat preservation layer, 17. Furnace body support, 18. Motor, 19. Motor support. Detailed implementation manner

[0039] In order to enable those skilled in the art to better understand and implement the technical solution of the present utility model, the present utility model will be further described below in conjunction with specific embodiments and the accompanying drawings, but the specific embodiments cited do not limit the present utility model.

[0040] Currently, the following problems exist in thin-walled tubes:

[0041] (1) Some cold-formed alloy tubes such as cold-rolled thin-walled tubes and cold-spun thin-walled tubes have very thin wall thicknesses, with no machining allowance or extremely limited machining allowance. However, their straightness is poor and straightening operations are required, and the existing technology is insufficient.

[0042] (2) After the forming process of cold-formed thin-walled tubes, the tubes often need to be annealed to remove stress and homogenize the structure, reducing the anisotropy of the tube body. For finished thin-walled tubes, their wall thickness is very thin, and stress release during heat treatment is more uneven, and the tube body may bend.

[0043] To solve the straightening problems of thin-walled tubes in the above two situations, the present utility model provides a device for heat treatment and hot straightening of finished thin-walled tubes, as shown in Figure 1 , Figure 2 , Figure 3 and Figure 4 shown, including:

[0044] A heating furnace chamber, the inner wall of the heating furnace chamber is provided with a heating element;

[0045] A heat treatment furnace chamber, disposed in the heating furnace chamber, the heat treatment furnace chamber is provided with a heat treatment cavity 9-1, the thin-walled tube 6 is disposed in the heat treatment cavity 9-1, a plurality of metal rings 8 are sleeved outside the thin-walled tube 6, and the metal rings 8 are fixed to the outside of the thin-walled tube 6 through the first fixing piece 7; a plurality of annular grooves 9-2 are provided along the circumferential direction on the inner wall of the heat treatment cavity 9-1, the annular grooves 9-2 are matched with the metal rings 8, and the metal rings 8 can roll along the annular grooves 9-2;

[0046] The transmission assembly is arranged outside the heating furnace chamber. The output end of the transmission assembly passes through the heating furnace chamber and is fixedly connected to one end of the heat treatment furnace chamber, and is used to drive the heat treatment furnace chamber to rotate.

[0047] As the heat treatment furnace chamber rotates, the metal rings 8 on the outer side of the thin-walled tube 6 roll along the annular groove 9-2, so that the thin-walled tube 6 rotates and revolves along the inner wall of the heat treatment cavity 9-1. This device can rely on the self-weight of the thin-walled tube 6 and the weight of the counterweight to reduce the deformation problem caused by uneven stress release during and after the heat treatment of the thin-walled tube with good straightness, straighten the thin-walled tube with poor straightness, improve the straightness, the device has a simple structure, can be reused, does not need to prepare a variety of molds, and has low cost.

[0048] In a preferred embodiment, the heating element can be a resistance wire, which is used to provide heat for the heat treatment furnace chamber and provide a temperature environment for the hot straightening process. By energizing the resistance wire, it generates heat by itself, so as to reach the temperature required for hot straightening.

[0049] In a preferred embodiment, the heating furnace chamber includes a heating furnace chamber box body 14 and a heating furnace chamber cover plate 15. The heating furnace chamber box body 14 is placed on the furnace body support 17. The inner wall of the heating furnace chamber box body 14 is provided with a heat preservation layer 16, and a resistance wire is arranged in the heat preservation layer 16. The material of the heat preservation layer 16 can be selected as heat preservation and heat insulation asbestos. The heating furnace chamber box body 14 and the heating furnace chamber cover plate 15 are fixed by a third fixing member. Specifically, when implemented, the fixing method of the third fixing member can adopt the Figure 2 fixing method of cooperating the first bolt 3 and the nut 4 as shown.

[0050] In a preferred embodiment, the heat treatment furnace chamber is arranged in the heating furnace chamber box body 14. The heat treatment furnace chamber is used to place the thin-walled tube 6 and provide the temperature environment and gas environment required for the heat treatment of the thin-walled tube 6. The heat source of the heat treatment furnace chamber is provided by the heating furnace chamber. In a preferred embodiment, a heat treatment cavity 9-1 is arranged in the heat treatment furnace chamber. The thin-walled tube 6 is placed in the heat treatment cavity 9-1. As Figure 2 , Figure 3 , Figure 6 , Figure 7 and Figure 11 shown, a plurality of metal rings 8 are sleeved on the outer side of the thin-walled tube 6, and the metal rings 8 are fixed on the outer side of the thin-walled tube 6 by a first fixing member 7; a plurality of annular grooves 9-2 are formed in the inner wall of the heat treatment cavity 9-1 along the circumferential direction, and the annular grooves 9-2 are matched with the metal rings 8, and the metal rings 8 can roll along the annular grooves 9-2; the metal rings 8 provide the functions of fixing, counterweight and rolling guidance for the thin-walled tube 6.

[0051] When the metal ring 8 rolls, a part of the surface of the thin-walled tube 6 is in contact with the inner wall of the heat treatment chamber 9-1. It should be noted that the device for heat treatment and thermal straightening of the finished thin-walled tube provided by the present utility model has the following two functions: The first is to prevent the originally straight thin-walled tube from bending or flattening during heat treatment, that is, its heat treatment function; The second is to straighten the thin-walled tube with poor straightness during heat treatment, that is, its thermal straightening function. The specific function of this contact is that when the thin-walled tube 6 rolls while in contact with the inner wall of the heat treatment chamber 9-1, at any moment, the force on the thin-walled tube 6 along its length is uniform. At any moment, the supporting force received by the thin-walled tube 6 is evenly distributed on the line in contact with the inner wall of the heat treatment chamber 9-1, so it will not bend due to gravity. If the thin-walled tube 6 does not contact the inner wall of the heat treatment chamber 9-1 when it rolls, at any moment, the supporting force received by the thin-walled tube 6 only comes from the support provided by the metal ring 8. Except for these support points, the rest of the thin-walled tube 6 is in a suspended state. For a very long thin-walled tube, under the action of heat, the material resistance of the thin-walled tube itself decreases, and under the action of gravity, the suspended position may collapse, causing the thin-walled tube to bend.

[0052] In order to ensure the stability of the movement of the thin-walled tube 6 during heat treatment, in a preferred embodiment, a plurality of metal rings 8 are evenly sleeved outside the thin-walled tube 6, and the center of each metal ring 8 is located on the axis of the thin-walled tube 6. The function of configuring a plurality of metal rings 8 is beneficial to ensuring the stability of the thin-walled tube 6 during rotation and revolution. Preferably, 3 metal rings 8 are provided, respectively near the two ends and the middle of the thin-walled tube 6. The number and position of the metal rings 8 correspond to those of the annular groove 9-2.

[0053] In order to facilitate adjustment, in a preferred embodiment, the first fixing member 7 is a screw rod. The metal ring 8 is radially provided with a plurality of threaded round holes, preferably 6 round holes. Each round hole is threadedly connected with a screw rod, and the 6 screw rods fix the center of the metal ring 8 on the axis of the thin-walled tube 6. A cross groove is provided on the end face of the screw rod, and tools such as a screwdriver can be used to adjust the depth of the screw rod relative to the outer circle of the metal ring 8, so as to adjust the hole size formed by the plurality of screw rods to match the outer diameter sizes of different thin-walled tubes. That is to say, a set of metal rings 8 and the first fixing member 7 can fix thin-walled tubes of multiple diameters. When the diameter of the thin-walled tube 6 changes, only the position of the first fixing member 7 relative to the round hole needs to be adjusted radially to make the center of the metal ring 8 located on the axis of the thin-walled tube 6.

[0054] In a preferred embodiment, the heat treatment furnace chamber includes a heat treatment furnace chamber box body 9 and a heat treatment furnace chamber cover plate 12, and the two are fixed with a second fixing member. Specifically, when implemented, the second fixing member can be selected such as Figure 2The second bolt 5 shown is fixed. Before fixing, a high-temperature sealant needs to be brushed on the joint surface. Inside the heat treatment furnace chamber box body 9, there is configured the heat treatment cavity 9-1, as Figure 8 and Figure 9 shown. On the outer side of the heat treatment furnace chamber cover plate 12, there are configured an air inlet hole 10 and an exhaust hole 11. The air inlet hole 10 and the exhaust hole 11 are communicated with the heat treatment cavity. The air inlet hole 10 and the exhaust hole 11 are equipped with high-temperature resistant air valves, so that the atmosphere environment during heating can be selectively adjusted, such as vacuum, argon, etc.

[0055] In a preferred embodiment, as Figure 5 shown, at the bottom of the inner wall of the heating furnace chamber box body 14, there are provided rollers 13, and the rollers 13 serve as the rotational support of the heat treatment furnace chamber 9.

[0056] In a preferred embodiment, the transmission assembly includes a first transmission gear 1, a second transmission gear 2, and a motor 18. The output end of the motor 18 is fixedly connected to the first transmission gear 1. The first transmission gear 1 and the second transmission gear 2 are engaged. The rotating shaft of the second transmission gear 2 passes through the heating furnace chamber box body 14 and is fixedly connected to one end of the heat treatment furnace chamber box body 9 away from the heat treatment furnace chamber cover plate 12. The motor 18 is placed on the motor bracket 19. Driven by the motor 18, the second transmission gear 2 drives the heat treatment furnace chamber box body 9 to rotate. Inside the heat treatment furnace chamber box body 9, there is a heat treatment cavity 9-1. Inside the inner wall of the heat treatment cavity 9-1, there is provided an annular groove 9-2, which is matched with the size of the metal ring 8. As the heat treatment furnace chamber box body 9 rotates, the metal ring 8 rotates and revolves along the inner wall of the heat treatment cavity 9-1. The thin-walled tube 6 rotates in the same way as the metal ring 8. The metal ring 8 provides the functions of fixing, counterweight, and rolling guidance for the thin-walled tube 6. Relying on the self-weight of the thin-walled tube 6 and the weight of the counterweight of the metal ring 8, the deformation problem caused by uneven stress release during and after the heat treatment of the thin-walled tube with good straightness is reduced, and the thin-walled tube with poor straightness is straightened to improve the straightness.

[0057] In actual production, a heat treatment furnace chamber with a larger specification can be made. For example, a plurality of heat treatment cavities 9-1 can be opened in the heat treatment furnace chamber, and each heat treatment cavity 9-1 is configured with one thin-walled tube 6, so as to realize the processing of multiple pipe fittings in one furnace, as Figure 10 and Figure 11 shown.

[0058] The following takes a specific embodiment to illustrate the operation process of the present device. Specifically:

[0059] Select a thin-walled tube 6 prepared by cold spinning process of titanium alloy with a size of Φ100×1×1200 mm. Fix a metal ring 8 with an outer diameter of 124 mm and an inner diameter of 112 mm on the outer side of the thin-walled tube 6 using a first fixing member 7, and ensure that the thin-walled tube 6 and the metal ring 8 are concentric. The distance between the three metal rings 8 is 300 mm, and the distance from the fixing rings at both ends to the ends of the thin-walled tube 6 is 300 mm.

[0060] Open the heating furnace chamber cover plate 15 and the heat treatment furnace chamber cover plate 12 respectively, and place the fixed structure of the thin-walled tube 6 into the heat treatment cavity 9-1. Align the metal ring 8 with the annular groove 9-2 on the inner wall of the heat treatment cavity 9-1, adjust the position of the first fixing member 7 to ensure that the thin-walled tube 6 and the metal ring 8 are concentric, and one side of the thin-walled tube 6 must be closely attached to the inner wall of the heat treatment cavity 9-1. After confirming the accurate placement, apply a high-temperature sealant on the joint surface between the heat treatment furnace chamber box 9 and the heat treatment furnace chamber cover plate 12, and then use the second bolt 5 to fix the heat treatment furnace chamber box 9 and the heat treatment furnace chamber cover plate 12. Then open the valve of the exhaust hole 11 and connect a vacuum pump to make the vacuum degree of the heat treatment cavity 9-1 ≤ 1.3×10 -3 Pa or more, and then close the valve of the exhaust hole 11 and confirm that the valve of the air inlet hole 10 is in the closed state.

[0061] Close the heating furnace chamber cover plate 15, and use the first bolt 3 and the nut 4 to fix the heating furnace chamber box 14 and the heating furnace chamber cover plate 15. Before closing, confirm that the roller 13 is in good condition and there are no obvious defects in roundness.

[0062] Connect the power supply to supply power to the resistance wire, set the temperature to 800 °C, and at the same time turn on the temperature detection device to ensure that the temperature in the furnace is normal. Start the motor, the motor 18 drives the first transmission gear 1 to rotate, and the second transmission gear 2 drives the heat treatment furnace chamber box 9 to rotate. Adjust the rotation speed of the motor 18 so that the rotation speed of the heat treatment furnace chamber box 9 is 0.5 r / min.

[0063] One hour and thirty minutes later, the temperature of the heat treatment furnace chamber box 9 reaches 800 °C, start timing, stop supplying power to the resistance wire after two hours of heat preservation, and then after five hours, the temperature of the heat treatment furnace chamber drops to 200 °C, and turn off the motor 18. Then after 3 hours, the temperature of the heat treatment furnace chamber box 9 drops to 50 °C, open the heating furnace chamber cover plate 15 and the heat treatment furnace chamber cover plate 12, take out the thin-walled tube 6 from the furnace, remove the first fixing member 7 and the metal ring 8, obtain the thin-walled tube 6, complete the heat treatment process of the pipe fitting, and conduct the straightness inspection of the pipe fitting.

[0064] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and its equivalent technologies, these changes and modifications are also intended to be included therein.

Claims

1. An apparatus for heat treatment and hot straightening of a finished thin-walled tube, characterized in that, Including: A heating furnace chamber, with heating elements arranged on the inner wall of the heating furnace chamber; A heat treatment furnace chamber, arranged within the heating furnace chamber. A heat treatment cavity (9-1) is arranged within the heat treatment furnace chamber. A thin-walled tube (6) is arranged within the heat treatment cavity (9-1). A plurality of metal rings (8) are sleeved outside the thin-walled tube (6), and the metal rings (8) are fixed to the outside of the thin-walled tube (6) by first fixing members (7). A plurality of annular grooves (9-2) are circumferentially formed on the inner wall of the heat treatment cavity (9-1), and the annular grooves (9-2) match the metal rings (8), and the metal rings (8) can roll along the annular grooves (9-2); A transmission assembly, arranged outside the heating furnace chamber. The output end of the transmission assembly passes through the heating furnace chamber and is fixedly connected to one end of the heat treatment furnace chamber, for driving the heat treatment furnace chamber to rotate; As the heat treatment furnace chamber rotates, the metal rings (8) outside the thin-walled tube (6) roll along the annular grooves (9-2).

2. The device for heat treatment and hot straightening of the finished thin-walled tube according to claim 1, wherein When the metal rings (8) roll, there is a contact surface between the surface of the thin-walled tube (6) and the inner wall of the heat treatment cavity (9-1).

3. The device for heat treatment and hot straightening of the finished thin-walled tube according to claim 1, characterized in that, The center of each metal ring (8) is located on the axis of the thin-walled tube (6).

4. The device for heat treatment and hot straightening of a finished thin-walled tube according to claim 3, characterized in that, The first fixing member (7) is a screw. A plurality of threaded round holes are radially formed on the metal ring (8), and each round hole is threadedly connected with the first fixing member (7). The plurality of first fixing members (7) fix the center of the metal ring (8) on the axis of the thin-walled tube (6).

5. The device for heat treatment and hot straightening of a finished thin-walled tube according to claim 1, characterized in that, The heat treatment furnace chamber includes a heat treatment furnace chamber box body (9) and a heat treatment furnace chamber cover plate (12), which are hermetically fixed by second fixing members. The heat treatment cavity (9-1) is formed within the heat treatment furnace chamber box body (9). Air inlet holes (10) and air exhaust holes (11) are arranged on the outer wall of the heat treatment furnace chamber cover plate (12). The air inlet holes (10) and the air exhaust holes (11) communicate with the heat treatment cavity (9-1), and air stop valves are arranged on both the air inlet holes (10) and the air exhaust holes (11).

6. The device for heat treatment and hot straightening of the finished thin-walled tube according to claim 5, characterized in that, A plurality of heat treatment cavities (9-1) are formed within the heat treatment furnace chamber box body (9), and one thin-walled tube (6) is arranged in each heat treatment cavity (9-1).

7. The device for heat treatment and hot straightening of the finished thin-walled tube according to claim 5, characterized in that, The heating furnace chamber includes a heating furnace chamber box body (14) and a heating furnace chamber cover plate (15). The heating element is a resistance wire. A heat insulation layer (16) is arranged on the inner wall of the heating furnace chamber box body (14), and a resistance wire is arranged within the heat insulation layer (16). The heating furnace chamber box body (14) and the heating furnace chamber cover plate (15) are fixed by third fixing members.

8. The device for heat treatment and hot straightening of a finished thin-walled tube according to claim 7, characterized in that, Rollers (13) are arranged at the bottom of the inner wall of the heating furnace chamber box body (14), and the bottom of the heat treatment furnace chamber box body (9) abuts against the surface of the rollers (13).

9. The device for heat treatment and thermal straightening of a finished thin-walled tube according to claim 7, characterized in that, The transmission assembly includes a first transmission gear (1), a second transmission gear (2), and a motor (18). The output end of the motor (18) is fixedly connected to the first transmission gear (1). The first transmission gear (1) meshes with the second transmission gear (2). The rotating shaft of the second transmission gear (2) passes through the heating furnace chamber box body (14) and is fixedly connected to one end of the heat treatment furnace chamber box body (9) away from the heat treatment furnace chamber cover plate (12).

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