Roll changing device and work roll changing method based on roll changing device

Abstract

A roll changing device is applicable to a multi-roll mill. Under a roll changing state, assembly parts of the work rolls and the bearing chocks have a lateral movement space with the internal width not less than the assembly width of the work rolls and the bearing chocks in a lateral direction of the assembly parts moving along a rolling strip in a mill house, and the movement space allows another work rolls to coexist with used work rolls in the mill house before the used work rolls are pulled out. The roll changing device is provided with at least two rows of clamping heads, one row of clamping heads corresponding to an inlet side are inlet clamping heads, another row of clamping heads close to an outlet side are outlet clamping heads, each row of clamping heads comprises a pair of upper and lower clamping heads arranged in parallel.

Claims

1. A work roll changing method adopting a roll changing device for a multi-roll mill, wherein the multi-roll mill includes a pair of work rolls, a plurality of first work roll brackets, and second work roll brackets, the first work roll brackets and the second work roll brackets are respectively disposed at an inlet side and an outlet side of the mill, and are opposite to each other in a lateral direction, each of the work rolls are not provided with bearing chocks, or the work rolls are provided with bearing chocks, assembly parts of the work rolls and the bearing chocks have a lateral movement space with an internal width no less than an assembly width of the work rolls and the bearing chocks in the lateral direction along a rolling strip in a mill house in a roll changing state, the lateral direction is perpendicular to an axial direction of the work rolls, and the roll changing device is adapted to enter the mill house of the multi-roll mill and replace the work rolls with new work rolls, the roll changing device comprising a main body and at least two rows of clamping heads disposed on a same surface of the main body and arranged in the lateral direction, one of the rows of clamping heads are configured as inlet clamping heads, another one of the rows of clamping heads are configured as outlet clamping heads, each row of clamping heads comprises a pair of upper and lower clamping heads which are arranged in parallel, each upper and lower clamping heads comprises a bottom bracket groove and a clamper arranged on an upper portion of the bottom bracket groove at an interval, the clamper is capable of applying an acting force to a direction of the bottom bracket groove, and the upper and lower clamping heads are adapted to independently clamp and drive a corresponding one of the work rolls to move along the axial direction, wherein the roll changing device changes a pair of used work rolls by entering and exiting the mill house of the multi-roll mill only once, and the work roll changing method comprising the following steps: (1) switching the multi-roll mill to the roll changing state, opening a roll gap, and holding up the pair of used work rolls by the first work roll brackets of the multi-roll mill, while laterally moving the pair of used work rolls towards the inlet side of the mill by the first work roll brackets; (2) loading a pair of new work rolls by the outlet clamping heads of the roll changing device, and enabling the inlet clamping heads to be empty; (3) enabling the roll changing device to enter the mill house along the axial direction of the work rolls, wherein the new work rolls loaded by the outlet clamping heads are adjacent to the second work roll brackets; (4) holding up the new work rolls by the second work roll brackets; (5) clamping the pair of used work rolls by the inlet clamping heads of the roll changing device; (6) enabling the first work roll brackets to retract to a rolling state, wherein the pair of used work rolls is fixed only by the inlet clamping heads of the roll changing device; (7) unclamping the pair of new work rolls by the outlet clamping heads of the roll changing device, and holding up the new work rolls only by the second work roll brackets; (8) enabling the roll changing device to exit from the mill house, wherein the pair of used work rolls is loaded by the inlet clamping heads of the roll changing device, and the outlet clamping heads are empty; and (9) switching the mill to the rolling state, closing the roll gap, and enabling the second work roll brackets to retract to the rolling state, and ending roll changing.

2. The work roll changing method according to claim 1, wherein each row of clamping heads can only clamp a single work roll.

3. The work roll changing method according to claim 1, wherein when the new work rolls enter the mill house to be in position and before the used work rolls are pulled out of the mill house, the new work rolls and the used work rolls coexist in the mill house, and the new work rolls are not in contact with the used work rolls.

4. The work roll changing method according to claim 1, wherein the roll changing device loads the new work rolls to be changed before entering the mill house for roll changing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a rolling state diagram of a multi-roll mill in the prior art;

(2) FIG. 2 is a work roll changing preparation state diagram of FIG. 1;

(3) FIG. 3 is a work roll changing state diagram (a roll changing device is outside a mill house) of FIG. 1;

(4) FIG. 4 is a work roll changing state diagram (a roll changing device is in a mill house) of FIG. 1;

(5) FIG. 5 is a roll changing device implemented according to the present invention;

(6) FIG. 6 is another stereoscopic diagram of FIG. 5;

(7) FIG. 7 is a diagram of a mill switched from a rolling state to a work roll changing preparation state according to an efficient work roll changing method of the present invention;

(8) FIG. 8 is a state diagram of changing of work rolls of a mill implemented according to an efficient work roll changing method of the present invention (a roll changing device is outside a mill house when new rolls are pushed in);

(9) FIG. 9 is a state diagram of changing of work rolls of a mill implemented according to an efficient work roll changing method of the present invention (a roll changing device is in a mill house);

(10) FIG. 10 is a partial schematic diagram (intermediate rolls are omitted) of a state diagram of changing of work rolls of a mill implemented according to an efficient work roll changing method of the present invention (a roll changing device is in a mill house); and

(11) FIG. 11 is a state diagram of changing of work rolls of a mill implemented according to an efficient work roll changing method of the present invention (intermediate rolls are omitted when used rolls are pulled out).

DESCRIPTION OF THE EMBODIMENTS

(12) A roll changing device according to the present invention shown in FIG. 5 and FIG. 6 is applicable to a multi-roll mill and is characterized in that the multi-roll mill is not provided with bearing chocks, or work rolls are provided with bearing chocks. In a roll changing state, assembly parts of the work rolls and the bearing chocks have a lateral movement space with an internal width no less than an assembly width of the work rolls and the bearing chocks in a lateral direction of the assembly parts moving along a rolled strip in a mill house, and the lateral movement space allows another group of work rolls to coexist with used work rolls in the mill house before the used work rolls are pulled out of the mill house. The roll changing device 1 shown in FIG. 5 and FIG. 6 is provided with two rows of clamping heads (inlet clamping heads 3 and outlet clamping heads 2) corresponding to an inlet and an outlet of the rolling strip, the inlet clamping heads 3 and the outlet clamping heads 2 each comprise a pair of upper and lower clamping heads, and the four clamping heads are arranged in parallel.

(13) Further, the inlet clamping heads 3 and the outlet clamping heads 2 comprise bottom bracket grooves, and clampers capable of applying an acting force to the bracket grooves for clamping the work rolls tightly are arranged on upper portions of the bracket grooves at intervals. The bracket grooves are not limited to the shape in which the bearing bush-shaped internal arc in the figures matches the work rolls, and also may be in shapes in which the work rolls can be clamped, such as a v shape.

(14) Further, the inlet clamping heads 3 and the outlet clamping heads 2 are connected to clamping driving ends of head ends.

(15) According an efficient work roll changing work roll method according to the present invention shown in FIGS. 7-11, an 18-roll mill is taken as an example for describing a typical efficient work roll changing implementation. A similar roll changing method may also be adopted for efficient roll changing by other mills such as a 20-roll mill and a 36-roll mill.

(16) The present invention utilizes the typical feature that the work rolls of such multi-roll mills are not provided with bearing chocks and have a certain lateral movement space in the mill house, and two working processes of “pushing new rolls in and pulling used rolls out” are provided. Through the lateral movement space of the work rolls moving along the rolled strip in the mill house, the used work rolls move laterally (along an inlet or outlet direction of the rolling strip) when the mill switches to a roll changing state, thus an appropriate space is reserved for the new work rolls entering the mill house at first, and the new work rolls and the used work rolls can be placed in the mill house side by side, and details are as follows.

(17) (1) A mill switches to a roll changing state (shown in FIG. 7), a roll gap is opened, work roll brackets at an inlet side hold up a pair of used work rolls 8 needing to be changed (or a single work roll, a pair of work rolls taken as an example herein), and meanwhile laterally move toward the inlet side of the mill.

(18) (2) As shown in FIG. 8, a roll changing device 1 enters a mill house of the mill, outlet clamping heads 2 of the roll changing device load a pair of new work rolls 8, and inlet clamping heads 3 are in an empty carriage state.

(19) (3) The roll changing device 1 enters the mill house, and the new work rolls 8 loaded by the outlet clamping heads 2 are in position exactly in an axial direction during the process.

(20) (4) Work roll brackets 5 at an outlet side hold up the new work rolls 8, as shown in FIG. 9 and FIG. 10.

(21) (5) The inlet clamping heads 3 of the roll changing device 1 clamp the pair of used work rolls 8 close to the inlet side, as shown in FIG. 9 and FIG. 10.

(22) (6) The work roll brackets 4 at the inlet side retract to a rolling state (the pair of used work rolls 8 at the inlet side are fixed only by the inlet clamping heads 3 of the roll changing device 1 at the moment), and meanwhile, the work roll brackets 5 at the outlet side hold up the pair of new work rolls 8 just pushed in from the outlet side and stay still.

(23) (7) The outlet clamping heads 2 unclamp the pair of new work rolls 8 located at the outlet side (the new work rolls 8 are held up only by the work roll brackets 5 at the outlet side at the moment).

(24) (8) As show in FIG. 11, the roll changing device 1 exits from the mill house, with the inlet clamping heads 3 loading the pair of used work rolls 8, and the outlet clamping heads 2 being in an empty carriage state.

(25) (9) The mill switches to the rolling state (referring to a rolling state of a general mill in FIG. 1), the roll gap is closed, the work roll brackets 5 at the outlet side retract to the rolling state, and roll changing is completed.

(26) Compared with traditional roll changing methods, the efficient work roll changing method of the present invention has the advantages that operation times of the roll changing device are reduced, the roll changing time can be shortened by 30-60%, especially for wide strip steel mills with the longer movement distance of the roll changing device entering and exiting from the mill house, the roll changing time is significantly shortened by using the method of the present invention, and the operability of the mill is improved.