A double-sided symmetrical preheating device and preheating method for a thin-walled straight-seam welded pipe

Abstract

The application discloses a kind of double-side symmetrical preheating device and preheating method of thin-wall straight seam welded pipe, double-side symmetrical preheating device of thin-wall straight seam welded pipe includes mounting frame body and preheating component, the thin-wall straight seam welded pipe has a weld, the preheating component is installed on the mounting frame body by the moving assembly for driving its horizontal movement and vertical movement, the preheating component is equipped with a pair, when preheating, two thereof are respectively symmetrically arranged on the two sides of the thin-wall straight seam welded pipe, wherein the preheating component is towards the weld on the thin-wall straight seam welded pipe when preheating.The application uses two symmetrically distributed preheating components, double-side preheating avoids the disadvantages of uneven temperature distribution, its heating speed is gentle and stable, the temperature rise variation range of thin-wall straight seam welded pipe is small, effectively solve the problem of thermal stress imbalance of thin-wall straight seam welded pipe when unilateral heating, preheating process thin-wall straight seam welded pipe is small.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of welding auxiliary equipment, and particularly relates to a straight seam welded pipe preheating device and a preheating method. BACKGROUND

[0002] The straight seam welded pipe is widely used in the fields of oil, natural gas and water delivery, and its manufacturing process is crucial to product quality. Preheating is a key step before welding of the straight seam welded pipe, and directly affects the weld quality and the welded pipe performance. At present, the preheating of the straight seam welded pipe is mainly carried out by single-sided preheating in the ways of flame heating or resistance heating. However, for the thin-walled welded pipe, the single-sided preheating method will cause the problem of unbalanced thermal stress of the welded pipe, and will lead to a larger deformation of one side of the thin-walled welded pipe, thereby affecting the straightness of the welded pipe and its subsequent application. SUMMARY

[0003] The present application aims to overcome the above-mentioned deficiencies and defects in the background art, and to provide a double-sided symmetrical preheating device and a preheating method for a thin-walled straight seam welded pipe which is not easy to deform during preheating of the weld.

[0004] To solve the above technical problems, the technical solution provided by the present application is as follows:

[0005] A double-sided symmetrical preheating device for a thin-walled straight seam welded pipe, comprising a mounting frame body and a preheating assembly, the thin-walled straight seam welded pipe having one weld, the preheating assembly being mounted on the mounting frame body by a moving assembly for driving horizontal movement and vertical movement of the preheating assembly, the preheating assembly being provided with a pair of preheating assemblies, which are respectively arranged symmetrically on both sides of the thin-walled straight seam welded pipe during preheating, and one of the preheating assemblies faces the weld on the thin-walled straight seam welded pipe during preheating.

[0006] In the double-side symmetrical preheating device for the thin-wall straight-seam welded pipe, preferably, the moving assembly comprises a horizontal moving device and a vertical moving device. The horizontal moving device comprises a square base, a supporting base and a horizontal driver. The inner side of the square base is provided with a horizontal clamping groove. The supporting base is horizontally and rollably arranged in the horizontal clamping groove of the square base through horizontal rollers. The horizontal driver is arranged between the square base and the supporting base and is used to drive the horizontal movement of the supporting base. The vertical moving device is arranged on the supporting base. The horizontal rollers can be arranged in four, which facilitates the horizontal free sliding of the supporting base in the square base. The sliding of the supporting base is controlled by the horizontal driver. The horizontal driver can be a horizontal hydraulic cylinder. The extension and retraction of the horizontal hydraulic cylinder can drive the sliding of the supporting base in the square base, thereby realizing the adjustment of the position of the supporting base. Since the vertical moving device is arranged on the supporting base and the preheating assembly is arranged on the vertical moving device, the horizontal movement of the supporting base can drive the horizontal movement of the vertical moving device, thereby driving the horizontal movement of the preheating assembly. In combination with the vertical movement of the vertical moving device, the horizontal and vertical adjustment of the preheating assembly can be realized.

[0007] In the double-side symmetrical preheating device for the thin-wall straight-seam welded pipe, preferably, the vertical moving device comprises a jacking base, a jacking frame and a vertical driver. The jacking base is arranged on the supporting base. The inner side of the jacking base is provided with a vertical clamping groove. The jacking frame is vertically and rollably arranged in the vertical clamping groove of the jacking base through vertical rollers. The vertical driver is arranged between the supporting base and the jacking frame and is used to drive the vertical movement of the jacking frame. The preheating assembly is connected with the jacking frame. The vertical rollers can be arranged in four, which facilitates the vertical free sliding of the jacking frame in the jacking base. The sliding of the jacking frame is controlled by the vertical driver. The vertical driver can be a vertical hydraulic cylinder. The extension and retraction of the vertical hydraulic cylinder can drive the sliding of the jacking frame in the jacking base, thereby realizing the adjustment of the position of the jacking frame. Since the preheating assembly is connected with the jacking frame, the vertical movement of the jacking frame can drive the vertical movement of the preheating assembly. In combination with the horizontal movement of the horizontal moving device, the horizontal and vertical adjustment of the preheating assembly can be realized.

[0008] In the double-side symmetrical preheating device for the thin-wall straight-seam welded pipe, preferably, the length of the preheating assembly matches the length of the thin-wall straight-seam welded pipe, the preheating assembly comprises an infrared heating pipe and a preheating shell, the infrared heating pipe is arranged in the preheating shell, and the preheating shell is connected with the moving assembly; the preheating shell is further provided with an infrared temperature measuring sensor and a laser distance measuring sensor. The thin-wall straight-seam welded pipe is heated by the infrared heating mode, the heat efficiency is high, the temperature control range is wide, and the preheating temperature before welding required by the preheating of most thin-wall straight-seam welded pipes can be met. The preheating shell adopts a concave shell, the preheating area is large, and the heat source is concentrated. The preheating shell is connected with the jacking frame of the vertical moving device, and a reinforcing steel plate can be arranged at the connecting position of the preheating shell and the jacking frame. The infrared temperature measuring sensor and the laser distance measuring sensor in the preheating shell are respectively used for measuring the preheating temperature and the distance between the infrared heating pipe and the weld, and are used for guiding the preheating process.

[0009] In the double-side symmetrical preheating device for the thin-wall straight-seam welded pipe, preferably, the mounting frame body is further provided with a straightness measuring assembly for real-time monitoring of the straightness of the thin-wall straight-seam welded pipe.

[0010] In the double-side symmetrical preheating device for the thin-wall straight-seam welded pipe, preferably, the straightness measuring assembly comprises a straightness measuring instrument and a lead screw moving assembly for driving the straightness measuring instrument to move linearly along the surface of the thin-wall straight-seam welded pipe, the length of the lead screw moving assembly matches the length of the thin-wall straight-seam welded pipe, that is, the moving space provided by the lead screw moving assembly for the straightness measuring instrument needs to meet the demand of the straightness measurement of the whole thin-wall straight-seam welded pipe.

[0011] In the double-side symmetrical preheating device for the thin-wall straight-seam welded pipe, preferably, the lead screw moving assembly comprises a sliding block, a lead screw set and a lead screw driving source for driving the rotation of the lead screws in the lead screw set, the straightness measuring instrument is arranged on the sliding block, the sliding block is connected with the lead screw set, the lead screw driving source is connected with the lead screw set, and the length direction of the lead screw set is parallel to the length direction of the thin-wall straight-seam welded pipe; the straightness measuring assembly further comprises a wire rail for supplying power to the straightness measuring instrument, and the wire rail is arranged parallel to the lead screw set. Under the driving of the lead screw driving source, the lead screws in the lead screw set rotate and convert the rotary motion into linear motion of the sliding block, thereby driving the straightness measuring instrument to move linearly along the surface of the thin-wall straight-seam welded pipe, and the straightness of the surface of the thin-wall straight-seam welded pipe is measured. The lead screw driving source can comprise a servo motor, a shaft coupling and the like, and conventional existing devices can be used. The wire rail is arranged close to the lead screw set, the wire moves synchronously with the straightness measuring instrument, and is used for providing electric energy.

[0012] In the double-side symmetrical preheating device for the thin-wall straight-seam welded pipe, preferably, the mounting frame body comprises a gantry and a screw rod mounting support located below the gantry, the moving assembly is connected with the gantry, and the straightness measurement assembly is provided with three sets, two of which are arranged on the screw rod mounting support and located at two sides of the gantry, and the other one is arranged at the central top of the gantry. The three straightness measurement assemblies form a triangle and measure the straightness of the thin-wall straight-seam welded pipe at different positions on the surface of the thin-wall straight-seam welded pipe, which can be used for measuring the straightness of the thin-wall straight-seam welded pipe during the preheating operation, monitoring the deformation degree of the thin-wall straight-seam welded pipe in real time, and the measurement result is more accurate. The three straightness measurement assemblies can be connected on the control system through PLC and connected on a power supply, and the start and stop control of the device can be realized through the control button, and then the three sets of devices can realize the three-point straightness monitoring of the thin-wall straight-seam welded pipe synchronously.

[0013] In the double-side symmetrical preheating device for the thin-wall straight-seam welded pipe, preferably, the lower part of the inner cavity of the gantry is provided with a conveying roller for bearing and conveying the thin-wall straight-seam welded pipe, and the top of the gantry is provided with a camera. The conveying roller is used for conveying the thin-wall straight-seam welded pipe into the inner cavity of the gantry and providing bearing force. The camera is used for monitoring the position and state of the thin-wall straight-seam welded pipe, so as to facilitate the operator to adjust in time.

[0014] As a general technical concept, the application also provides a preheating method of the double-side symmetrical preheating device for the thin-wall straight-seam welded pipe.

[0015] S1: the preheating assembly is located at an avoiding position, the thin-wall straight-seam welded pipe is sent into the mounting frame body, and the weld of the thin-wall straight-seam welded pipe is located at the 3 o'clock or 9 o'clock direction. The 3 o'clock or 9 o'clock direction is defined as follows: taking a common clock as an example, the 12 o'clock direction is located at the uppermost, and the 3 o'clock or 9 o'clock direction is located at the horizontal two sides of the thin-wall straight-seam welded pipe.

[0016] S2: the position of the preheating assembly is adjusted through the moving assembly, one of the preheating assemblies faces the weld on the thin-wall straight-seam welded pipe, and the other one faces the other side of the thin-wall straight-seam welded pipe away from the weld, and the preheating is started. At the same time of starting the preheating, the straightness measurement assembly is started, the straightness of the thin-wall straight-seam welded pipe is monitored in real time by using the straightness measurement assembly, and the preheating parameters are adjusted in time if the monitoring result of the straightness measurement assembly is abnormal.

[0017] S3: after the preheating is completed, the preheating assembly and the straightness measurement assembly are stopped, and the thin-wall straight-seam welded pipe is sent out.

[0018] The preheating method of the application distinguishes from the traditional straightness measurement after the production of the thin-wall straight seam welded pipe, and the straightness monitoring and accurate measurement of the thin-wall straight seam welded pipe are realized by using the straightness measurement assembly during the preheating of the thin-wall straight seam welded pipe by using the preheating assembly (i.e. the preheating and measurement are simultaneously performed), so that the straightness deformation of the thin-wall straight seam welded pipe during the preheating of the weld can be timely reflected, so that corresponding adjustment measures can be taken, the straightness deformation of the thin-wall straight seam welded pipe after the preheating is reduced, and the overall quality of the thin-wall straight seam welded pipe after the preheating is ensured.

[0019] The installation direction of the double-side symmetrical preheating device of the thin-wall straight seam welded pipe of the application is the same as the direction of the production line, and is arranged on the side of the production line, so that the preheating device is located on both sides of the production line, and the thin-wall straight seam welded pipe is transported to the outside of the preheating device by the conveying roller on the production line in the actual production process. The specific preheating method can be as follows:

[0020] (1) When the thin-wall straight seam welded pipe reaches the predetermined position on the production line, the operator observes and operates the rotating roller on the production line to rotate the weld of the thin-wall straight seam welded pipe to the 9 o'clock or 3 o'clock direction, and then transports the thin-wall straight seam welded pipe to the inside of the gantry by the conveying roller. Before the step is performed, the horizontal moving device is at the farthest limit position away from the thin-wall straight seam welded pipe, which is the initial position of the preheating assembly, so as to avoid the collision between the thin-wall straight seam welded pipe and the preheating assembly and cause safety accidents.

[0021] (2) When the thin-wall straight seam welded pipe enters the inside of the gantry, the straightness measurement assembly is started to monitor the pipe type of the thin-wall straight seam welded pipe in real time. The operator starts the vertical moving device, and the vertical hydraulic cylinder starts to provide power. The preheating assembly is aligned with the weld by the camera observation, and the two preheating assemblies are respectively located on both sides of the thin-wall straight seam welded pipe and are symmetrically distributed. During the operation, the operator should pay attention to control the rising height of the jacking frame to avoid excessive rising of the jacking frame. After the preheating assembly is aligned with the weld, the horizontal moving device can be started to slowly push the preheating assembly to the thin-wall straight seam welded pipe direction, and when the preheating assembly is 20mm away from the thin-wall straight seam welded pipe, the laser distance sensor senses and immediately stops the forward movement, and the preheating is started. After the preheating is completed, the output power of the power supply can be adjusted according to the on-site working condition to perform the heat preservation treatment or the straightness measurement assembly is stopped to run, the horizontal moving device and the vertical moving device automatically slide to the original position, the conveying roller transports the thin-wall straight seam welded pipe to the next production line, and waits for the next preheating.

[0022] The double-side symmetrical preheating device and preheating method for the thin-wall straight seam welded pipe of the present application is designed for the preheating process before the welding of the thin-wall straight seam welded pipe (such as the thin-wall steel pipe with a wall thickness / diameter outer diameter less than 0.02), which can drive the preheating assembly to synchronously and uniformly preheat the double sides of the thin-wall straight seam welded pipe by means of the hydraulic moving assembly, greatly reducing the deformation of the thick wall and the length direction of the thin-wall straight seam welded pipe. Compared with the traditional flame heating method, the device uses infrared heating, overcoming the problem of difficult temperature control. Compared with the traditional resistance heating method, the device avoids the disadvantage of uneven temperature distribution. The preheating device and preheating method of the present application have a gentle and stable heating speed, a small temperature rise change range of the thin-wall straight seam welded pipe, and effectively solve the problem of unbalanced thermal stress of the welded pipe during unilateral heating. At the same time, the straightness and temperature of the thin-wall straight seam welded pipe are monitored by the straightness measuring assembly and the infrared temperature sensor, which can timely reflect the preheating condition, such as when the pipe type deformation of one side is slightly large, the temperature can be adjusted in time to reduce the deformation. The above device combination can greatly improve the preheating efficiency and reduce the deformation of the thin-wall straight seam welded pipe, and is more conducive to obtaining the thin-wall straight seam welded pipe with good weld preheating effect.

[0023] The double-side symmetrical preheating device and preheating method for the thin-wall straight seam welded pipe of the present application can preheat the weld of the thin-wall straight seam welded pipe with different diameters and lengths on the production line by adjusting the horizontal distance of the horizontal moving device and the height of the vertical moving device. The entire device can be used in combination, and one set to multiple sets can be combined according to the length of the thin-wall straight seam welded pipe to completely heat the thin-wall straight seam welded pipe.

[0024] Compared with the prior art, the present application has the following advantages:

[0025] 1. The double-side symmetrical preheating device and preheating method for the thin-wall straight seam welded pipe of the present application uses two symmetrically distributed preheating assemblies, which avoids the disadvantage of uneven temperature distribution, has a gentle and stable heating speed, a small temperature rise change range of the thin-wall straight seam welded pipe, effectively solves the problem of unbalanced thermal stress of the thin-wall straight seam welded pipe during unilateral heating, and has small deformation during the preheating process.

[0026] 2. The double-side symmetrical preheating device and preheating method for the thin-wall straight seam welded pipe of the present application can adjust the horizontal distance and vertical height of the preheating assembly by the moving assembly to preheat the two sides of the thin-wall straight seam welded pipe with different diameters on the production line. The entire device can be used in combination, and one set to multiple sets can be combined according to the length of the thin-wall straight seam welded pipe to completely heat the thin-wall straight seam welded pipe. The preheating device and preheating method can heat the thin-wall straight seam welded pipe with different diameters and lengths, and is suitable for the production line of the thin-wall straight seam welded pipe with different diameters.

[0027] 3, The double-side symmetrical preheating device and preheating method of the thin-wall straight seam welded pipe have the advantages of simple structure and easy operation, can greatly improve the preheating efficiency of the thin-wall straight seam welded pipe and reduce the deformation rate of the straight seam welded pipe. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor under the premise of the drawings.

[0029] Figure 1 It is a structural schematic view of the double-side symmetrical preheating device of the thin-wall straight seam welded pipe of the present application.

[0030] Figure 2 It is a front view of the double-side symmetrical preheating device of the thin-wall straight seam welded pipe of the present application.

[0031] Figure 3 It is a side view of the double-side symmetrical preheating device of the thin-wall straight seam welded pipe of the present application.

[0032] Figure 4 It is a structural schematic view of the horizontal moving device of the present application.

[0033] Figure 5 It is a structural schematic view of the vertical moving device of the present application.

[0034] Figure 6 It is a structural schematic view of the preheating assembly of the present application.

[0035] Figure 7 It is a partial enlarged schematic view of the preheating shell of the preheating assembly of the present application.

[0036] Figure 8 It is a structural schematic view of the straightness measuring assembly of the present application.

[0037] Figure 9 It is a partial structural schematic view of the straightness measuring assembly of the present application.

[0038] LEGEND

[0039] S1, weld; 1, straightness measurement assembly; 101, straightness measurement instrument; 102, screw rod moving assembly; 1021, sliding block; 1022, screw rod set; 1023, screw rod driving source; 103, linear rail; 2, mounting frame body; 201, gantry frame; 202, screw rod mounting support; 3, preheating assembly; 301, infrared heating tube; 302, preheating shell; 304, infrared temperature measurement sensor; 305, laser distance measurement sensor; 4, horizontal moving device; 401, square frame base; 4011, horizontal clamping groove; 402, supporting base; 403, horizontal driver; 405, horizontal roller; 5, vertical moving device; 501, jacking seat; 5011, vertical clamping groove; 502, jacking frame; 503, vertical driver; 504, vertical roller; 6, conveying roller; 7, camera. DETAILED DESCRIPTION

[0040] In order to facilitate the understanding of the present application, the following will be a more comprehensive and detailed description of the present application in conjunction with the drawings and preferred embodiments of the specification, but the protection scope of the present application is not limited to the following specific embodiments.

[0041] It should be particularly noted that when an element is described as "fixed to, fixedly connected to, connected to or communicated to" another element, it can be directly fixed, fixedly connected, connected or communicated to another element, or indirectly fixed, fixedly connected, connected or communicated to another element through other intermediate connecting elements.

[0042] Unless otherwise defined, all professional terms used herein have the same meaning as generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the protection scope of the present application.

[0043] Unless otherwise specified, various instruments and equipment used in the present application can be purchased on the market or can be prepared by existing methods.

[0044] Embodiment:

[0045] As shown in Figures 1-3 The double-sided symmetrical preheating device of the thin-wall straight-seam welded pipe of the present embodiment includes a mounting frame body 2 and a preheating assembly 3. The thin-wall straight-seam welded pipe has one weld S1, and the wall thickness / diameter of the thin-wall straight-seam welded pipe is less than 0.02. The preheating assembly 3 is mounted on the mounting frame body 2 through a moving assembly for driving its horizontal movement and vertical movement. The preheating assembly 3 is provided with a pair of preheating assemblies 3, which are respectively arranged symmetrically on both sides of the thin-wall straight-seam welded pipe during preheating. One of the preheating assemblies 3 faces the weld S1 of the thin-wall straight-seam welded pipe during preheating.

[0046] Specifically, as shown in Figure 4As shown in the figure, in the embodiment, the moving assembly comprises a horizontal moving device 4 and a vertical moving device 5. The horizontal moving device 4 comprises a square base 401, a support base 402 and a horizontal driver 403. The inner side of the square base 401 is provided with a horizontal clamping groove 4011. The support base 402 is horizontally rollably arranged in the horizontal clamping groove 4011 of the square base 401 through four horizontal rollers 405. The horizontal driver 403 is arranged between the square base 401 and the support base 402, and is used to drive the support base 402 to move horizontally. The vertical moving device 5 is arranged on the support base 402. In the embodiment, the horizontal driver 403 can be a horizontal hydraulic cylinder.

[0047] Specifically, as shown in the figure, Figure 5 In the embodiment, the vertical moving device 5 comprises a jacking base 501, a jacking frame 502 and a vertical driver 503. The jacking base 501 is arranged on the support base 402. The inner side of the jacking base 501 is provided with a vertical clamping groove 5011. The jacking frame 502 is up-down rollably arranged in the vertical clamping groove 5011 of the jacking base 501 through four vertical rollers 504. The vertical driver 503 is arranged between the support base 402 and the jacking frame 502, and is used to drive the jacking frame 502 to move up and down. The preheating assembly 3 is connected with the jacking frame 502. In the embodiment, the vertical driver 503 can be a vertical hydraulic cylinder.

[0048] As shown in the figure, Figure 6 , Figure 7 In the embodiment, the length of the preheating assembly 3 matches the length of the thin-wall straight-seam welded pipe. The preheating assembly 3 comprises an infrared heating pipe 301 and a preheating shell 302. The infrared heating pipe 301 is arranged in the preheating shell 302. The preheating shell 302 is connected with the jacking frame 502. The preheating shell 302 is further provided with an infrared temperature sensor 304 and a laser distance measuring sensor 305. Specifically, the preheating assembly 3 comprises two sets. The specification of each set can be 3000-6000mm×200-400mm. The two sets of preheating assemblies 3 are located at the same horizontal height. The preheating shell 302 is made of heat-resistant material and can withstand a maximum temperature of 1000℃. Heat insulation material is arranged around the inside of the preheating shell 302 to prevent the infrared temperature sensor 304 and the laser distance measuring sensor 305 at the end from being burned out due to excessively high temperature.

[0049] As shown in the figure, Figure 1 , Figure 8 , Figure 9 In the embodiment, the mounting rack 2 is further provided with a straightness measuring assembly 1 for real-time monitoring of the straightness of the thin-wall straight-seam welded pipe. The straightness measuring assembly 1 comprises a straightness measuring instrument 101 and a lead screw moving assembly 102 for driving the straightness measuring instrument 101 to move linearly along the surface of the thin-wall straight-seam welded pipe. The length of the lead screw moving assembly 102 matches the length of the thin-wall straight-seam welded pipe.

[0050] Specifically, in the embodiment, the screw moving assembly 102 comprises a sliding block 1021, a screw rod set 1022, and a screw rod driving source 1023 for driving the screw rod in the screw rod set 1022 to rotate, the straightness measuring instrument 101 is arranged on the sliding block 1021, the sliding block 1021 is connected with the screw rod set 1022, the screw rod driving source 1023 is connected with the screw rod set 1022, and the length direction of the screw rod set 1022 is parallel to the length direction of the thin-wall straight-seam welded pipe; the straightness measuring assembly 1 further comprises a track 103 for supplying power to the straightness measuring instrument 101, and the track 103 is arranged parallel to the screw rod set 1022.

[0051] In the embodiment, the mounting rack body 2 comprises a gantry 201 and a screw rod mounting support 202 located below the gantry 201, the moving assembly is connected with the gantry 201, the straightness measuring assembly 1 is provided with three sets, two of which are arranged on the screw rod mounting support 202 and located at two sides of the gantry 201 respectively, and the other set is arranged at the central top of the gantry 201.

[0052] In the embodiment, the lower part of the inner cavity of the gantry 201 is provided with a conveying roller 6 for bearing and conveying the thin-wall straight-seam welded pipe; and the top of the gantry 201 is provided with a camera 7.

[0053] In other embodiments, the number of gantries 201 and the number of straightness measuring assemblies 1 can also be adjusted, and the present application does not make any limitation.

[0054] In the embodiment, the horizontal driver 403, the vertical driver 503, the infrared heating pipe 301, the infrared temperature measuring sensor 304, the laser distance measuring sensor 305, the straightness measuring instrument 101, the screw rod driving source 1023, and the screw rod set 1022 can all adopt existing conventional devices.

[0055] The preheating method of the bilateral symmetrical preheating device for the thin-wall straight-seam welded pipe in the embodiment comprises the following steps:

[0056] S1: The preheating assembly 3 is located at the avoiding position, the thin-wall straight-seam welded pipe is sent into the mounting rack body 2, and the weld S1 of the thin-wall straight-seam welded pipe is located at the 3 o'clock or 9 o'clock direction;

[0057] S2: The position of the preheating assembly 3 is adjusted by the moving assembly, one of the preheating assemblies 3 is directed towards the weld S1 on the thin-wall straight-seam welded pipe, the other preheating assembly 3 is directed towards the other side of the thin-wall straight-seam welded pipe away from the weld S1, and the preheating is started; and at the same time when the preheating is started, the straightness measuring assembly 1 is started, the straightness of the thin-wall straight-seam welded pipe is monitored in real time by the straightness measuring assembly 1, and if the monitoring result of the straightness measuring assembly 1 is abnormal, the preheating parameters are adjusted in time;

[0058] S3: After the preheating is completed, the preheating assembly 3 and the straightness measuring assembly 1 are stopped, and the thin-wall straight-seam welded pipe is sent out.

[0059] More specifically, the preheating method can be as follows:

[0060] S1: When the thin-walled straight seam welded pipe reaches the predetermined position on the production line, the operator observes through camera 7 and operates the rotating roller on the production line to rotate the weld seam of the thin-walled straight seam welded pipe to the 3 o'clock position (e.g., ...). Figure 1 (As shown), the thin-walled straight seam welded pipe is then transported into the gantry 201. Before proceeding to this step, the horizontal moving device 4 is at its furthest limit from the thin-walled straight seam welded pipe, which is the initial position of the preheating component 3, to avoid collision between the thin-walled straight seam welded pipe and the preheating component 3 and thus prevent a safety accident.

[0061] S2: After the thin-walled straight seam welded pipe enters the gantry 201, the straightness measurement component 1 is activated to monitor the pipe's shape in real time. The operator activates the vertical movement device 5, and the vertical hydraulic cylinder begins to provide power. The camera 7 is used to observe and align the preheating component 3 with the weld seam S1. The two preheating components 3 are located symmetrically on both sides of the thin-walled straight seam welded pipe. During operation, the operator should carefully control the rising height of the lifting frame 502 to avoid excessive rising. Once the preheating component 3 is aligned with the weld seam S1, the horizontal movement device 4 can be activated to slowly advance the preheating component 3 towards the thin-walled straight seam welded pipe. When the preheating component 3 is 20mm away from the thin-walled straight seam welded pipe, it is immediately stopped by the laser rangefinder 305, and preheating begins. Once preheating is complete, the power output can be adjusted according to the on-site conditions for heat preservation, or the straightness measuring component 1 can be stopped. The horizontal moving device 4 and the vertical moving device 5 will automatically slide back to their original positions, and the conveying roller 6 will transport the thin-walled straight seam welded pipe to the next production line, waiting for the next preheating.

[0062] The double-sided symmetrical preheating device and method for thin-walled straight seam welded pipes in this embodiment employs two symmetrically distributed preheating components 3. Double-sided preheating avoids the drawbacks of uneven temperature distribution, resulting in a gentle and stable heating rate and minimal temperature rise variation in the thin-walled straight seam welded pipe. This effectively solves the problem of unbalanced thermal stress in thin-walled straight seam welded pipes during unilateral heating, and minimizes deformation of the thin-walled straight seam welded pipe during the preheating process. Furthermore, the double-sided symmetrical preheating device and method in this embodiment allows for adjustment of the horizontal distance and vertical height of the preheating components 3 by moving the components, enabling preheating of thin-walled straight seam welded pipes of different diameters on the production line from both sides before welding. The entire device can be used in combination; one or more sets can be combined depending on the length of the thin-walled straight seam welded pipe to achieve complete heating of the pipe.

Claims

1. A double-sided symmetrical preheating device for a thin-walled straight-seam welded pipe, comprising a mounting frame body (2) and a preheating assembly (3), the thin-walled straight-seam welded pipe having a weld seam (SI), characterized in that, The preheating assembly (3) is installed on the mounting frame body (2) through a moving assembly for driving horizontal and vertical movement thereof, and is provided with a pair of preheating assemblies (3) which are symmetrically arranged on both sides of the thin-walled straight seam welded pipe during preheating, one of which is directed towards the weld (S1) on the thin-walled straight seam welded pipe during preheating; the mounting frame body (2) is further provided with a straightness measuring assembly (1) for real-time monitoring of the straightness of the thin-walled straight seam welded pipe; The length of the preheating assembly (3) matches the length of the thin-walled straight seam welded pipe, and the preheating assembly (3) comprises an infrared heating pipe (301) and a preheating shell (302), the infrared heating pipe (301) is arranged in the preheating shell (302), and the preheating shell (302) is connected with the moving assembly; the preheating shell (302) is further provided with an infrared temperature sensor (304) and a laser distance measuring sensor (305). The straightness measuring assembly (1) comprises a straightness measuring instrument (101) and a lead screw moving assembly (102) for driving the straightness measuring instrument (101) to move linearly along the surface of the thin-walled straight seam welded pipe, and the length of the lead screw moving assembly (102) matches the length of the thin-walled straight seam welded pipe.

2. The apparatus for preheating of thin walled straight seam welded pipe of claim 1, wherein, The moving assembly comprises a horizontal moving device (4) and a vertical moving device (5), the horizontal moving device (4) comprises a square frame base (401), a supporting base (402) and a horizontal driver (403), the inner side surface of the square frame base (401) is provided with a horizontal clamping groove (4011), the supporting base (402) is horizontally rollably arranged in the horizontal clamping groove (4011) of the square frame base (401) through a horizontal roller (405), and the horizontal driver (403) is arranged between the square frame base (401) and the supporting base (402) and used for driving the supporting base (402) to move horizontally, and the vertical moving device (5) is arranged on the supporting base (402).

3. The apparatus for preheating of thin walled straight seam welded pipe of claim 2, wherein, The vertical moving device (5) comprises a jacking base (501), a jacking frame (502) and a vertical driver (503), the jacking base (501) is arranged on the supporting base (402), the inner side surface of the jacking base (501) is provided with a vertical clamping groove (5011), the jacking frame (502) is up-down rollably arranged in the vertical clamping groove (5011) of the jacking base (501) through a vertical roller (504), and the vertical driver (503) is arranged between the supporting base (402) and the jacking frame (502) and used for driving the jacking frame (502) to move up and down, and the preheating assembly (3) is connected with the jacking frame (502).

4. The apparatus for preheating of thin walled straight seam welded pipe of claim 1, wherein, The screw moving assembly (102) comprises a sliding block (1021), a screw group (1022) and a screw driving source (1023) for driving the rotation of the screw in the screw group (1022), the straightness measuring instrument (101) is arranged on the sliding block (1021), the sliding block (1021) is connected with the screw group (1022), the screw driving source (1023) is connected with the screw group (1022), and the length direction of the screw group (1022) is parallel to the length direction of the thin-wall straight-seam welded pipe. The straightness measuring assembly (1) further comprises a track (103) for supplying power to the straightness measuring instrument (101), and the track (103) is arranged parallel to the screw group (1022).

5. The apparatus for preheating of thin walled straight seam welded pipe of claim 1, wherein, The mounting rack body (2) comprises a gantry (201) and a screw mounting support (202) located below the gantry (201), the moving assembly is connected with the gantry (201), the straightness measuring assembly (1) is provided with three sets, two of which are arranged on the screw mounting support (202) and located on the two sides of the gantry (201), and the other set is arranged on the top center of the gantry (201).

6. The apparatus for preheating of thin walled straight seam pipe of claim 5, wherein, The lower part of the inner cavity of the gantry (201) is provided with a conveying roller (6) for carrying and conveying the thin-wall straight-seam welded pipe; and the top of the gantry (201) is provided with a camera (7).

7. A method of preheating a thin-walled straight-seam welded pipe by a double-sided symmetrical preheating device according to any one of claims 1 to 6, characterized in that, The method comprises the following steps: Step 1: the preheating assembly (3) is located in a avoiding position, the thin-wall straight-seam welded pipe is sent into the mounting rack body (2), and the weld (S1) of the thin-wall straight-seam welded pipe is located at 3 o'clock or 9 o'clock direction; Step 2: the position of the preheating assembly (3) is adjusted by the moving assembly, one of the preheating assemblies (3) is towards the weld (S1) of the thin-wall straight-seam welded pipe, the other preheating assembly (3) is towards the other side of the thin-wall straight-seam welded pipe away from the weld (S1), and the preheating is started; and at the same time of starting the preheating, the straightness measuring assembly (1) is started, the straightness of the thin-wall straight-seam welded pipe is monitored in real time by the straightness measuring assembly (1), if the monitoring result of the straightness measuring assembly (1) is abnormal, the preheating parameters are adjusted in time; Step 3: after the preheating is completed, the preheating assembly (3) and the straightness measuring assembly (1) are stopped, and the thin-wall straight-seam welded pipe is sent out.

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