Development trend of uncoiling, leveling and shearing line for 6mm hot-rolled steel coil

Abstract : Analyzed and compared the technical status of previous products and current products, and formulated product technical specifications and process flow. Products have been manufactured and placed on the market.

Key words : high line speed ; flatness ; large coil width ; uncoiling tension ; no scratches ; processing flow ;

China's total steel output ranks first in the world for nine consecutive years , and has reached an annual output of 400 million tons ;
China is the world's largest steel consumer , but the per capita consumption is one-fifth of that of developed countries , and the market demand will have a lot of room for growth ;
China's consumption mode mainly depends on the direct supply of steel mills or the supply of steel agents , and the processing and distribution capacity only accounts for 10 % of the supply ~ 15%, a serious waste of resources; while the distribution rate of steel products in the United States reaches 70 % , and the distribution rate of steel products in Europe reaches 55 %;
The authenticity rate of plates in our country is very low , especially for special steel plates and high-strength steel plates . At present, many of them still rely on imports . The main reason is that the leveling and shearing equipment for processing is low , the internal stress relief cannot meet the cutting requirements , and the flatness of the plate surface is poor. .
1 Comparison of technical status of products
The technical indicators of new and old steel plate materials are listed in Table 1 .

Table 1 Comparison table of technical status of new and old products
technical indicators	previous products	current product
Steel coil mass /t	<20	<30
width/ mm	1 000 ~ 1 500	800 ~ 1800
Tensile strength /MPa	450	650
Yield strength /MPa	235	360
Flatness/ (mm/m)	6	1 . 5
Cutting length accuracy /mm	±5	±1
Diagonal/ mm	<6	<1 . 5
Pallet shape/ mm	<10	<2
surface requirements	none	no scratches
glitch requirement	<1mm	<3% plate thickness
Trimming straightness/ (mm/m)	<10	<0 . 5
stress relief	no request	No stress changes during cutting
Linear speed/ (m/min)	20	60

2 Machine Specifications
21 Main Performance Analysis
This equipment is a special equipment for uncoiling , precision straightening and accurate sizing of steel coils . The main working host of this equipment is composed of main mechanisms such as uncoiler , pinch feeding machine , straightening machine , and length-setting mechanism , and is supplemented by transportation , buffering , guiding , and conveying devices in the middle .

When the equipment is working, the pinch mechanism is in the feeding state. The sheet passes through the feeding straight head machine , cuts off the irregular head , and then enters the pit looper after being leveled by the 15 -roller quadruple straightening machine. After centering , the sheet metal is leveled again by the five-roller re-leveling machine , and the pinch and sizing device feeds the material to the press according to the set size . When the set size is reached, the feeding is stopped and the signal is sent to the press .
of the equipment, such as feeding , straightening , and sizing, is automatically coordinated when it is working , and will not stretch the sheet ; the size and number of sheets can be automatically calculated and displayed . In addition, the touch screen also has feeding speed setting, automatic and manual exchange setting , feeding value setting , feeding number setting , automatic start , automatic stop , temporary stop , counter reset , feeding , returning , Scissors up , scissors down, abnormal alarm and other functions .
The design and production of this equipment pay attention to the protection of the board surface .
After the manual threading of the equipment is completed , the rest of the time the whole line is in an automatic working state .
22 Analysis of the characteristics of the main functional components
a ) Uncoiler : Hydraulic rotary cylinder is used to realize the expansion and contraction of the reel , and it is controlled by the AC frequency conversion motor to realize the active feeding when leading the material , and the back tension is generated during normal operation , so as to realize the tension uncoiling , avoiding the deviation of the sheet when it is running and the sheet when the sheet is opened. Mutual scratches on the surface ;
b ) Leveling machine : A 15- roller quadruple leveling machine is used to ensure the flatness of the plate leveling and eliminate the internal stress of the plate. By adjusting the different pressing amounts of the support rollers , the pressing amounts of the entrance and exit can be different , and different roll shapes can be obtained, which can effectively improve the leveling accuracy. In order to facilitate the cleaning of dust and scale on the surface of the board , a set of roller cleaning device is added to the leveling machine to facilitate cleaning of dirt ;

1. Length system : digital feeding control is adopted , and the feeding accuracy of length is up to 0.5mm /2m . Change the way of the traditional sizing wheel , The production efficiency has been increased by more than 1 times , and the sizing accuracy has been greatly improved at the same time . The overall technical level is advanced and the performance is reliable ;
2. In the way of sizing, the feeding length is directly input from the liquid crystal display on the operating table , and there is a digital display on the operating table . Quantitative and output of plates are automatically controlled by the counter ;
3. Automation control : the actions of each part of the production line , The whole machine is controlled by PLC , High degree of automation , Good reliability. The whole line adopts the method of fieldbus , which is convenient for connection and improves the control performance ;
4. Anti-scratch treatment : the production line abandons the traditional practice , All transitions are handled by rollers or rubber wheels , avoid sliding contact , There is no contact between the board surface and the plane during normal operation , Can avoid sheet scratches .

23 production line scope of application
The scope of application of wire products is listed in Table 2 .
Table 2 Scope of application of the production line

serial number	Scope of application and indicators	value
1	Machinable material	Hot rolled pickled plate
2	Machinable plate thickness / mm	1.5 ~ 6 (% <300MPa % <500MPa)
3	Machinable board width / mm	600 ~ 1800
4	Allowable steel coil inner diameter /mm	610 , 762
5	Permissible outer diameter of steel coil/ mm	C2 000
6	Allowable steel coil mass /t	<30

24 main technical parameters of the production line
The main technical parameters of the wire are listed in Table 3 .

Table 3 Main Technical Parameters of Wire Rod

serial number	index	value
1	Cutting accuracy of length /mm	Soil 0.5/2000 ( by length )
2	Leveling line speed /(m/min)	0 ~ 60
3	Diagonal error/ (mm/m)	<0.8
4	Cutting finished product speed/(sheet /min)	16 ~ 20
5	Cutting blanking length range /mm	500 ~ 6000

3 Process configuration of the production line
The wire rod production process is as follows: material storage platform - feeding trolley - hydraulic double-head uncoiler f feed guide plate device f feed plate centering device - pinch and 15 -roller quadruple straightening machine - intermediate bridge - side guide deviation correction device -Five -roll re-leveling machine - pinch and sizing device - high-speed transverse shearing machine - conveying platform - pneumatic discharge mechanism - collecting hydraulic lifting platform - collecting conveying seat . The equipment is controlled by hydraulic pneumatic system and electrical system .
in conclusion
The servo high-speed feeding and shearing line is adopted to solve the problems of low configuration, low precision and low speed of hot - rolled pickling plate uncoiling line . At present , the line of this configuration has been put on the market , and the use effect is very good .

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