The 20-high Sendzimir mill is a single stand reversible cold mill. Its main feature is that 20 rollers are embedded in a "zero-crown" integral cast steel frame in an annular overlapping way. Under the stress of the rolling mill frame, the rolling mill deforms uniformly in the width direction, with small contact arc length and small work roll diameter, which is not easy to deform, and can realize large reduction and high-speed continuous rolling of thin strip. The roll system of 20-high Sendzimir mill consists of 2 working rolls, 4 first intermediate rolls, 6 second intermediate rolls and 8 backup rolls. Both the screw-down mechanism and the adjusting mechanism adopt hydraulic cylinders or hydraulic motors, and the gear connected with the eccentric wheel is driven by a rack and pinion to realize parameter adjustment. In this way, the thrust of hydraulic cylinder or hydraulic motor only needs to overcome the friction between sliding surfaces caused by rolling component, which greatly reduces the volume of hydraulic equipment and rolling mill.
1 composition of roll system
The composition of the roll system is shown in figure 1.
In the figure, S, T- work roll: nominal roll diameter: 63.5mm；;
Minimum winding diameter: 58mm, maximum winding diameter: 73.5mm；;
O, P, Q, R—— First intermediate roller: nominal roller diameter:102 mm; ;
Minimum winding diameter: 96mm, maximum winding diameter:105 mm; ;
I, J, K, L, M, N—— Second intermediate roller: nominal roller diameter:173mm; ; Minimum winding diameter: 170mm, maximum winding diameter:173mm; ;
A, b, c, d, e, f, g, h- backup roller:
Nominal coil diameter: 300.02mm；;
Minimum winding diameter: 297mm, and maximum winding diameter: 300.02mm.
In this mill, only the second intermediate roller is a driving roller, and the other rollers are free rollers, which rotate by friction between rollers.
2 Down adjustment
The reduction adjustment of the rolling mill (see Figure 2) is realized by supporting rollers B and C. Two hydraulic cylinders installed on the shell of the mill drive two gears at the shaft end. The gear and the eccentric wheel are connected with the supporting shaft through a key. When the gear rotates, the inner center of the eccentric wheel rotates around the inner center of the eccentric ring to complete the pressing function and realize the adjustment of the roll gap. In Figure 2:
Coordinates 1: S 1 = 2.574, S2=2.9 12.
A(+400.05，2 15.9)，B(+ 149.225，400.05)
I(+ 17 1.833， 167.277)，J(0，225.238)
O(+52.879，98.3 12)，S(0，34.662)
T(0，-34.324)，R(+53.3 15，-97.6 1)
M(0，-234.353)，N(+ 17 1.8 18，- 167.347)
G(+ 149.225，-400.05)，H(+400.05，-2 15.9)
Coordinate 2: S 1 =-3.46 1, S2=-3. 15.
A(+400.05，2 15.9)，B(+ 149.225，400.05)
I(+ 173.544， 159.86)，J(0，2 16.8 1)
O(+54.722，90.668)，S(0.28.595)
T(0，-28.289)，R(+55. 153，-89.98)
M(0，-2 15.934)，N(+ 173.524，- 159.94 1)
G(+ 149.225，-400.05)，H(+400.05，-2 15.9)
In Figure 2, the coordinate 1 represents the relative position relationship of the roll system when the lateral eccentricity is 0, the rolling and reduction amount is the maximum opening, the As-u roll is in the middle position and the roll diameter is the nominal diameter; Coordinate 2 is the relative position relationship of the roll system when the side eccentricity is 0, the rolling line and reduction are the minimum openings, the As-u roll is in the middle position and the roll diameter is the nominal diameter.
As can be seen from Figure 2, the eccentricity of the eccentric wheel is 6.35mm, and when the roller diameter is the nominal diameter, the lower press gear rotates 74.3 140mm within the stroke range of the lower press rack, and the second one is in the middle.
The displacement of the center of the roller "J" in the downward direction is 8.425 mm, the displacement of the center of the first intermediate roller in the downward direction is 7.644 mm, and the displacement of the upper work roller is 6.607 mm. ..
Because the centers of roller A and roller D are unchanged under the condition of constant roll diameter, when pressing J, the centers of roller I, roller K, roller O and roller P will be displaced downward and in the rolling direction at the same time to ensure that the rollers are in contact with each other. However, because the contact point between the rollers is always on the connecting line between the centers of the two contact rollers, the reduction amount of the work roller can be determined under the conditions of certain roller diameter, lateral eccentricity and rack reduction stroke.
3 components -u-roll adjustment
As-u roller adjustment: Seven racks are driven by seven hydraulic cylinders, so that the eccentricity on the B and C axes of the roller rotates around the saddle center of the support roller, so that the support shaft is bent, and the relative height between the support bearings is changed to adjust the axial roller gap, thus ensuring the shape of the product. The specific values of coordinates 1, 2 and 3 in Figure 3 are as follows:
Coordinates 1: S0 = 0. 14.
C( 149.225，400.05)，D(400.05，2 15.9)
J(0，22 1.986)，K( 172.7 15， 163.3 18)
P(53.262，95.22 1)，S(0.3 1.89)
Coordinate 2: S0 = 0.09 1
C( 149.225，400.05)，D(400.05，2 15.9)
J(0，22 1.663)，K( 172.78， 163.039)
P(53.334，94.928)，S(0.3 1.659)
Coordinate 3: S0 = 0.343
C( 149.225，400.05)，D(400.05，2 15.9)
J(0，222.236)，K( 172.649， 163.602)
P(53.225，95.455)，S(0.32.093)
Coordinates 1, 2 and 3 in fig. 3 indicate that the bending amount of As-u roll is eccentrically adjusted at position 5, position 10 and position 0 (that is, the stand is in the middle position, high position and low position), and it is pressed at the middle position, the side eccentricity is at position 0 and the nominal roll diameter.
As can be seen from the coordinate values in Figure 3, when the rack moves for five pitches, the gear rotates 2× 16.36 = 32.72, and the roll bending at the working shaft is 0.434 mm The relative size relationship is similar to the screw-down adjustment, except that the As-u roll is adjusted as a single bearing instead of the whole support roll bearing, and the rotation center of the support roll bearing is different. When the As-u roll is adjusted, the eccentricity of the inner and outer centers is 1.0 16mm, which makes the center of the supporting bearing offset, thus achieving the purpose of bending the roll. According to the relative relationship between rollers in the figure, the relationship between roller bending and rack stroke can be calculated.
4-side eccentricity adjustment
The adjustment of side eccentricity is used to compensate the change of roll diameter. The adjustment is realized by the hydraulic motor driving the gear connected to the eccentric wheel with eccentricity of 3. 175mm on the same shaft, and the eccentric wheel, that is, the bearing, rotates around the center of the support.
As can be seen from fig. 2, the eccentric relative positions of rollers A, D, E and H .. When the gear on the supporting shaft rotates180, the lateral eccentricity adjustment reaches the maximum value of 3.175 mm. ..
5 Adjustment of rolling line height
The height adjustment of the rolling line is realized by the hydraulic cylinder driving the rack to move, and the rack pushes the gear connected with the eccentric wheel through the key. The principle and structure of adjustment are basically the same as that of side eccentricity adjustment, but the difference is that the gear on the support shaft is at the other end (operating side), and the eccentricity is different. As can be seen from Figure 2, when the eccentricity of the eccentric wheel is 6.35mm and the rack moves 140mm, the gear (eccentric wheel) rotates 74.3 1 and the rolling height is adjusted to 6.035 mm. ..
1450 main technical parameters of twenty-high mill:
Rolling mill specification: 20- high precision cold rolling mill
Roller system diameter (mm): working roller: 63.5mm
First intermediate roller: φ 102mm
Second intermediate roller: φ 173mm
Driving roller: φ 173mm
Support bearing: 300mm
Roll surface width (mm): work roll 1450mm.
Raw material specification (mm): 2.0-4.0 * 1270 (maximum) finished product specification (mm): 0.10-1.2 *1270 (maximum) maximum rolling force: 900KN.
Maximum rolling speed: 600 m/min.
Main motor power: 1000KW*2.
Winding motor power: 630KW*6
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Twenty-high mill
This paper mainly introduces the roll system structure of 20-high Sendzimir mill, and analyzes the distribution and adjustment of its working roll, intermediate roll and backup roll.
The 20-high Sendzimir mill is a single stand reversible cold mill. Its main feature is that 20 rollers are embedded in a "zero-crown" integral cast steel frame in an annular overlapping way. Under the stress of the rolling mill frame, the rolling mill deforms uniformly in the width direction, with small contact arc length and small work roll diameter, which is not easy to deform, and can realize large reduction and high-speed continuous rolling of thin strip. The roll system of 20-high Sendzimir mill consists of 2 working rolls, 4 first intermediate rolls, 6 second intermediate rolls and 8 backup rolls. Both the screw-down mechanism and the adjusting mechanism adopt hydraulic cylinders or hydraulic motors, and the gear connected with the eccentric wheel is driven by a rack and pinion to realize parameter adjustment. In this way, the thrust of hydraulic cylinder or hydraulic motor only needs to overcome the friction between sliding surfaces caused by rolling component, which greatly reduces the volume of hydraulic equipment and rolling mill.