With the continuous development of the domestic steel structure industry, H-shaped steel has been widely used in many steel structure factories, airports, high-rise buildings and bridges. H-shaped steel was originally rolled by steel mills. However, due to the limited size of rolling steel and its price is much higher than that of ordinary high-quality steel plates, welded H-shaped steel has gradually become the preferred structural profile in the design and production of structural steel structures. Welding H-shaped steel The demand has increased significantly year by year. The use of manual and mechanical assembly welding to produce welded H-beams is not efficient due to low production efficiency, but it is far from meeting the need for high-speed development of construction steel structures. Therefore, in order to improve the production efficiency of welded H-beams, it is an inevitable trend to organize the production of automatic production lines.
Wuxi Yangtong Machinery & Equipment Co., Ltd. has been manufacturing welding equipment for H-beam assembly, welding, rectification and multi-head cutting machines for light steel production since 1994. So far, it has been successfully applied in more than 400 user units. In early 1996, Shanghai Zhongyuan Kawasaki Steel Structure Co., Ltd. first ordered medium-sized welded H-beam automatic production lines from our company. In the first half of the year, the design, trial production, and commissioning were successful. Normal production was put into operation and good economic benefits were achieved. So far, our company has produced more than 10 similar welded H-beam automatic production lines. The main users are: Wuhan Iron and Steel Metal Structure Factory, Tangshan 22 Metallurgical Structure Co., Ltd., Zhejiang Zhongnan Group, Shanghai Zhenhua Port Machinery and Shanghai Pearl Stone and other units. The actual production application proves that the welding H-beam automatic production line has achieved the expected results.
First, welding H-beam assembly welding process
Welding H-beam assembly welding process in accordance with the scope of the production of H-type steel specifications and technical requirements in many forms. FIG. 1 shows a block diagram of an assembly welding process for medium-sized welded H-shaped steels. The main processes include cutting blanking, assembly forming, spot welding, fillet weld automatic welding, workpiece turning, automatic welding of the other side fillet weld and flange correction. According to different technical requirements, pre-welding pre-treatment or post-weld shot-blasting treatment and cutting billet correction can also be added.
The main equipments of the production line include: numerical control/multi-head straight flame cutting machine, conveyor roller path, H-type assembly machine, 90° flip frame, first set of single-arm welding operation machine (two sets), 60° flip bracket, and translational machine. Two-stage conveyor roller, 180° chain turning machine, three-stage conveyor roller, second-group single-arm welding manipulator (two sets), 60° tilting bracket, translation machine, liftable hydraulic input roller, hydraulic flange correction Machine and can lift hydraulic output roller and so on.
The working procedure of the automatic production line is as follows:
1 The raw material steel plate is lifted from the bridge crane of the workshop to the cutting platform, and the multi-head cutting machine cuts the steel plate into flange plates and webs of different specifications and stacks them on the blank plate and web blank stacking area respectively.
2 Lift a flange plate and web to the input roller conveyor of the H-steel assembly point welding machine, and clamp and position the wing plate and web first by three sets of tie bar clamping mechanism, and input the workpiece into the host by the active input roller table. , Accurately position the workpiece and perform automatic point welding according to a predetermined procedure.
3 Turn the point-shaped T-shaped steel input tilting bracket upside down by 90°. Use a crane to hoist the other flange and T-shaped beam to the input roller. Repeat the same procedure to automatically solidify the assembly into H-shaped steel.
4 Assembled point-solid forming H-shaped steel is fed into the translation machine 1 and 2 of the A welding zone by the conveyor roller path. The lifting device of the translation machine lifts the H-shaped steel off the roller surface and feeds the steel to the welding manipulator 1 The bracket is turned over, and then the translation machine is detached from the workpiece. The workpiece is rotated by 45° by the flip bracket so that the seam is in the boat shape, and the first fillet weld is welded by the single-arm welding manipulator.
5 Article 1 After the fillet weld is completed, the bracket is turned to restore the workpiece, and then the workpiece is lifted by the translation machine into the tilting bracket of the second welding manipulator, and the workpiece is transferred to the 45 degree boat position from the second stage. The welding manipulator welds the second fillet weld.
6 Article 2 After the fillet weld is completed, the workpiece is sent to the conveyor roller conveyor by the translation machine, and the workpiece is fed into the 180° chain turning machine by the conveyor roller path, and then transferred to the B welding area by the conveyor roller path after being turned 180°. .
7 Repeat the same working procedure as in weld zone A and automatically complete the welding of the two fillet welds on the other side.
8 After the last fillet weld is completed, the workpiece is fed into the hydraulic flange straightener by a hydraulic conveyor roller until it meets the dimensional tolerances specified in the standard.
Second, processing steel specifications
H-beam flange width: 200～800mm
H-shaped steel flange plate height: 200 ~ 1200mm
H-shaped steel flange thickness: 6 ~ 40mm
H-shaped steel length: 4000 ~ 15000mm
Third, the technical characteristics of the main equipment of the production line
1. CNC/Multi-bar Straight Flame Cutting Machine
CNC/multi-bar straight flame cutting machine is a high-efficiency cutting and cutting equipment specially used for cutting steel plates into different width slats. It consists of T-shaped frame, longitudinal rail, longitudinal and lateral movement driving mechanism, gas supply system, electrical Control system, torch holder, adjustment mechanism and torch. The use of rack and pinion drive, smooth walking and cutting.
The track span of the CNC/multi-bar straight flame cutting machine can be selected from 3000 to 9000mm. The length of the track can be designed according to the feed length of the steel plate, usually between 12 ~ 15mm. The number of torches can be selected according to the user's requirements.
2.H steel assembly machine
The feature of the H-beam assembly machine is that it adopts the method of vertical assembly and solidification, which overcomes the problem of the low qualified rate of assembly of traditional horizontal assembly and solidification methods. The H-beam assembly point welding machine designed by our company consists of a gantry, positioning and pressing mechanism, tie bar clamping mechanism, main drive system, input roller path, output roller path, hydraulic system, electronic control system and CO2 gas protection. Welder and other eight major components.
The most important feature of this machine is the use of hydraulic transmission for the positioning of the wings and webs, and simultaneous mechanical clamping of the left and right sides to ensure the automatic and accurate centering of the wings and webs of different widths. The entire assembly and point welding process is fully controlled by a programmable logic controller (PLC). The length of the weld, the welding speed, the separation distance, and the idle movement speed between the two welding points can be set in advance.
3. One-arm welding manipulator
The welding of 4 fillet welds of H-beams can be performed using 4 single-arm welding machines, followed by fillet welds 1, 2, 3 and 4. A gantry welding manipulator can also be used to weld two fillet welds of two H-beams simultaneously. The welding H-beam automatic production line introduced in this article is equipped with 4 single-arm welding manipulators, and its advantages are more suitable for the rhythm of the flowing operation.
The single arm welding manipulator consists of a bogie body, a column, a cross beam, a sliding plate running mechanism, a motor drive system, a welding torch tracking mechanism, a flux conveying recovery system, a welding head, a welding power source, and an electric control system, and its structural outline is shown in FIG. 2.
The movement of the single arm welding operation machine trolley on the track is driven by the AC frequency converter to achieve stepless speed regulation. The drive mechanism drives the driven shaft through the sprocket wheel pair to form a two-axis four-wheel drive to ensure the smooth movement of the trolley. . The welding slide is installed on the crossbeam of the manipulator and can be moved by the motor to move up and down to meet the welding of different specifications of H-shaped steel. The welding head is installed at the end of the longitudinal slide. The special tracking mechanism can make the welding torch make three welds. Tracking. The distance between the welding torch and the surface of the workpiece is controlled by aerodynamic tracking. The position of the welding gun relative to the left and right positions of the seam and the rotation angle is a floating mechanical tracking, which ensures that the welding wire is always aligned with the centerline of the joint during the entire welding process, forming a uniform and high quality contour. Welds.
4. Chain type turning machine
The chain turning machine is designed to turn the H-beam to be welded to the required position and prevent the workpiece from being distorted during the turning process. The turning machine consists of two bases and four columns. Each column is equipped with a drive mechanism. The main motor drives the sprocket through the cycloid reducer. Above the sprocket there are two upper pulleys, where the upper pulley is mounted on the swing arm. The role of the upper pulley is to change the direction of movement of the chain and the position of the chain stretching. Two guide wheels are mounted on the lower part of the sprocket to increase the wrap angle of the chain on the sprocket, so that the sprocket can transmit power to the chain more effectively. Below the sprocket is also equipped with a lower pulley to change the position of the weight at the end of the chain. The upper part of the column is provided with a swing arm and a weight device respectively, and its role is that when the workpiece needs to be turned, the swing arm is turned downwards by an angle. When the flip is not required, the swing arm is raised and the chain is released, facilitating the conveying of the workpiece.
The two bases and the four columns form an integral body. Through the different combinations of the rotation directions of the driving sprocket of each column, the workpiece can be ascended, descended, turned (180°), and reset the chain. The end of each chain is equipped with a uniform weight so that the chain will not slide out due to external forces. There is also a trip switch on the column to prevent misoperation and malfunction.
5.H steel flange corrector
The H-beam flange straightening machine is composed of a base, a frame, a transmission roller, a motor drive mechanism, a top roller set, a pressing mechanism and a guide roller. Mainly used for the correction of the angular deformation of the flange plate after welding of the H-beam. The straightening machine presses the two sides of the upper and lower rollers to press the two sides of the flange, so that it produces plastic deformation in the opposite direction during continuous feeding. Complete continuous correction of H-beam flanges.
The main operating steps of the H-beam flange straightener are as follows:
(1) Adjust the position of the frame according to the width and thickness of the flange of the H-beam to be rectified so that the correction hole formed by the upper roller and the transmission roller meets the requirements for correction.
(2) According to the thickness of the web and the amount of longitudinal deformation, the guide roller is adjusted to the correct position so that it is not subjected to excessive axial force.
(3) After the correction hole is adjusted, the main motor is started to drive the transmission roller so that the H-shaped steel to be straightened is sent to the straightening machine for continuous correction of the flange. When the flange thickness exceeds 25mm, it usually takes several rounds of correction to meet the standard requirements.
Fourth, H-shaped steel automated production equipment
With the rapid development of the steel structure industry, the quality requirements of steel structure manufacturing are getting higher and higher. In particular, the surface treatment before welding of H-beam steel has become an important process in the production of steel structures. In response to this situation, the company developed the H-beam shot blasting machine at the end of 1998. It uses a roller conveyor to continuously clean the form, with a high degree of automation, surface cleanliness up to Sa21/2, and a certain degree of roughness to make the H-shaped steel paint After the attachment is solid, and solve the corrosion problem of H-shaped steel. At present, the equipment has been applied in nearly 60 steel structure production plants and has achieved good results.
V. Conclusion
(1) Years of production practice proves that our company's designed and produced welded H-beam automatic production line has greatly increased the production speed of welded H-shaped steel. The dimensions and weld quality of the produced welded H-shaped steel fully comply with the requirements of the relevant industry standards and professional standards, and it is worth promoting and applying.
(2) Welding H-beam automatic production line is a kind of low-cost automatic production equipment, which can obtain considerable economic benefits, and usually can fully recover equipment investment within two years.
(3) Various improvement plans can be adopted according to the needs of users, so that the equipment and production process layout of the welding H-beam automatic production line can be more reasonable, the production efficiency is higher, and the welding quality can be more easily guaranteed.
(4) For the production of high-quality welded H-section steel, the automatic production line process should increase the pre-weld steel plate pre-treatment or weld H-beam post-weld cleaning, and set up the corresponding shot blasting equipment.