阅读说明：本技术 一种防止定宽机打滑的方法 (Method for preventing width fixing machine from slipping ) 是由 幸利军 于 2020-07-01 设计创作，主要内容包括：一种防止定宽机打滑的方法,属热轧工艺领域。沿着板坯的前进方向,在定宽机的入口夹送辊和出口压紧辊后面,分别增加一个板坯实际位置检测设备,来获取板坯的实际运行位置；计算入口夹送辊的辊缝、入口压紧辊和出口压紧辊的一次辊缝以及入口压紧辊和出口压紧辊的二次辊缝；当板坯通过入口夹送辊时,根据入口夹送辊压力及板坯实际位置检测结果,将入口夹送辊由位置控制切换为压力控制；根据入口压紧辊和出口压紧辊压力和板坯实际位置检测结果,将入口压紧辊和出口压紧辊由位置控制切换为压力控制。可有效减少板坯在定宽机内打滑的问题,避免因减小入口夹送辊、入口压紧辊和出口压紧辊的辊缝而产生的冲击,和由此引起的辊面和机械设备的损伤。(A method for preventing a fixed width machine from slipping belongs to the field of hot rolling technology. Respectively adding a slab actual position detection device behind an inlet pinch roll and an outlet pinch roll of the width fixing machine along the advancing direction of the slab to obtain the actual running position of the slab; calculating a roll gap of an inlet pinch roll, a primary roll gap of an inlet pinch roll and an outlet pinch roll and a secondary roll gap of the inlet pinch roll and the outlet pinch roll; when the plate blank passes through the inlet pinch roll, switching the position control of the inlet pinch roll into pressure control according to the pressure of the inlet pinch roll and the actual position detection result of the plate blank; and switching the position control of the inlet compression roller and the outlet compression roller into pressure control according to the pressure of the inlet compression roller and the outlet compression roller and the actual position detection result of the plate blank. The problem that the plate blank slips in the width fixing machine can be effectively reduced, and the impact caused by reducing the roll gaps of the inlet pinch roll, the inlet compression roll and the outlet compression roll and the damage of the roll surface and mechanical equipment caused by the impact are avoided.)

1. A method for preventing a sizing machine from slipping is characterized in that:

1) along the advancing direction of the plate blank, arranging No. 1 detection equipment for the actual position of the plate blank behind an inlet pinch roll of the width fixing machine, wherein the detection equipment is used for detecting whether the plate blank passes through the inlet pinch roll;

2) along the advancing direction of the plate blank, behind the outlet pressing roller of the width fixing machine, detecting equipment No. 2 of the actual position of the plate blank is arranged and used for detecting whether the plate blank passes through the outlet pressing roller or not;

3) drawing steel by a heating furnace, and issuing the theoretical thickness H of the plate blank to a basic automation computer of a width setting machine by a process control computer;

4) respectively calculating a roll GAP PR GAP 1 of an inlet pinch roll and a primary roll GAP GR GAP 1 of an inlet compression roll and an outlet compression roll by a basic automatic computer of the width fixing machine according to the theoretical thickness H of the plate blank;

5) when the slab passes through the inlet pinch roll, if the pressure of the inlet pinch roll is equal to 50KN, a basic automation computer of the width fixing machine judges that the slab bites into the inlet pinch roll, and the position control of the inlet pinch roll is switched to pressure control;

6) if the pressure of the inlet pinch roll is always less than 50KN, but the slab is detected by No. 1 detection equipment at the actual position of the slab, and a basic automation computer of the width fixing machine judges that the slab passes through the inlet pinch roll, the position control of the inlet pinch roll is switched to the pressure control;

7) calculating the position of the plate blank by a basic automation computer of the width fixing machine, and calculating a secondary roll GAP GR GAP 2 of an inlet compression roller and an outlet compression roller by the basic automation computer of the width fixing machine after the plate blank passes through the outlet compression roller;

8) if the actual thickness h of the plate blank is larger than the roll gap between the inlet pressing roll and the outlet pressing roll, and when the pressure of the inlet pressing roll and the pressure of the outlet pressing roll are equal to 50KN, the basic automation computer of the width fixing machine judges that the plate blank passes through the outlet pressing roll, and the position control of the inlet pressing roll and the position control of the outlet pressing roll are switched to the pressure control;

9) if the pressure of the inlet compression roller and the pressure of the outlet compression roller are always less than 50KN, but the detection equipment of the actual position No. 2 of the slab detects the slab, and the basic automation computer of the width fixing machine judges that the slab passes through the outlet compression roller, the position control of the inlet compression roller and the position control of the outlet compression roller are switched to the pressure control;

10) and (6) ending.

2. The method for preventing the sizing machine from slipping as set forth in claim 1, wherein the roll GAP PR GAP 1 of the entry pinch roll is calculated by the following formula:

PR GAP 1 ═ H-a1 formula 1

Wherein H is the theoretical thickness of the plate blank; a1 ═ 10 mm.

3. The method for preventing the sizing machine from slipping according to claim 1, wherein the primary GAP GR GAP 1 between the inlet pinch roller and the outlet pinch roller is calculated as follows:

GR GAP 1 ═ H + B1 equation 2

Wherein H is the theoretical thickness of the plate blank; b1 ═ 40 mm.

4. The method for preventing the sizing machine from slipping according to claim 1, wherein the secondary GAP GR GAP 2 between the inlet pinch roller and the outlet pinch roller is calculated as follows:

GR GAP 2-H-B2 equation 3

Wherein H is the theoretical thickness of the plate blank; b2 ═ 10 mm.

5. The method for preventing the sizing machine from slipping according to claim 1, wherein the slab actual position No. 1 detecting device and the slab actual position No. 2 detecting device are object position detecting switches.

6. The method for preventing the sizing machine from slipping according to claim 5, wherein the device for detecting the actual position of the slab No. 1 and the device for detecting the actual position of the slab No. 2 are mechanical or photoelectric position detecting switches.

7. The method for preventing the sizing machine from slipping according to claim 5, wherein the device for detecting the actual position of the slab No. 1 and the device for detecting the actual position of the slab No. 2 are hot metal detectors.

8. The method for preventing the slip of the sizing machine according to claim 1, wherein the method for preventing the slip of the sizing machine obtains the actual running position of the slab by adding a slab actual position detecting device to the sizing machine after the entrance pinch roll and the exit pinch roll, respectively.

Technical Field

The invention belongs to the field of hot rolling processes, and particularly relates to a method for preventing a hot rolling width fixing machine from slipping.

Background

Referring to fig. 1, a Sizing Press (Sizing Press for short) is an apparatus for reducing the width of a slab by knocking the side of the slab during the movement of a strip in a forward direction 3 or stopping the strip while moving forward for a certain distance by reciprocating a module 2 in the width direction of the slab 1. The width fixing machine can reduce the width specification of continuous casting, and can improve the width control precision and reduce the head and tail cutting loss by controlling the shape after side pressing.

The existing control mode of the width fixing machine is shown in figures 2, 3, 4 and 5:

(1) drawing steel by the heating furnace, and issuing the theoretical thickness H of the plate blank to a basic automation computer L1 of a given width machine by a process control computer L2;

(2) a basic automatic computer L1 of the width fixing machine respectively calculates a roll GAP PR GAP 1 of an inlet pinch roll 4, a primary roll GAP GR GAP 1 of an inlet pinch roll 5 and a primary roll GAP GR GAP 1 of an outlet pinch roll 6 according to the theoretical thickness H of the plate blank and a formula 1 and a formula 2;

PR GAP 1 ═ H-a1 formula 1

GR GAP 1 ═ H + B1 equation 2

(3) When the slab passes through the inlet pinch roll, if the actual thickness h of the slab is larger than the roll gap of the inlet pinch roll, the slab can generate certain impact on the inlet pinch roll, and the pressure of the inlet pinch roll can rise; when the pressure > is 50KN, the basic automation computer of the width fixing machine judges that the slab bites into the inlet pinch roll, and the position control of the inlet pinch roll is switched to the pressure control;

(4) the basic automation computer of the width fixing machine calculates the position of the plate blank, and after the plate blank passes through the outlet compression roller, the basic automation computer of the width fixing machine calculates the secondary roller GAP GR GAP 2 of the inlet compression roller and the outlet compression roller according to a formula 3:

GR GAP 2-H-B2 equation 3

(5) If the actual thickness h of the plate blank is larger than the roll gaps of the inlet pressing roll and the outlet pressing roll, the pressure of the inlet pressing roll and the pressure of the outlet pressing roll can rise; when the pressure > is 50KN, the basic automation computer of the width fixing machine judges that the plate blank passes through the outlet pinch roller, and the position control of the inlet pinch roller and the outlet pinch roller is switched to the pressure control;

wherein

H: theoretical thickness of the plate blank;

h: the actual thickness of the slab;

GR GAP 1: primary roll gap;

GR GAP 2: secondary roll gap

A1＝10mm；

B1＝40mm；

B2＝10mm。

The prior art has the following disadvantages:

since the thickness H of the slab is theoretically calculated, a case often occurs in which the theoretically calculated thickness H is greater than the actual thickness H of the slab. If the deviation exceeds a certain range, the slab slips in the width fixing machine.

When the slab passes through the inlet pinch roll, if the actual thickness h of the slab is smaller than the roll gap of the inlet pinch roll, the slab cannot impact the inlet pinch roll, and the pressure of the inlet pinch roll cannot rise. At the moment, a basic automatic computer of the width fixing machine cannot judge whether the plate blank bites into the inlet pinch roll or not, and the position control of the inlet pinch roll cannot be switched to the pressure control. Thus, the slab is liable to slip in the width setter and stop advancing due to lack of pressing force and conveying force of the inlet pinch rolls.

Similarly, when the slab passes through the inlet pinch roller and the outlet pinch roller, if the actual thickness h of the slab is smaller than the roll gaps of the inlet pinch roller and the outlet pinch roller, the basic automation computer of the fixed width machine cannot judge whether the slab bites into the inlet pinch roller and the outlet pinch roller, the inlet pinch roller and the outlet pinch roller cannot be switched to be under pressure control through position control, and the slab is easy to slip.

The technical communication and the data inquiry show that the problem of slab slipping in the fixed width machine is common in each hot rolling production line. Because most of the thicknesses of the plate blanks can only be obtained through theoretical calculation, the situation that the thickness H calculated by the plate blank theory is larger than the actual thickness H cannot be fundamentally avoided. Some lines avoid the slip problem by reducing the entrance pinch roll GAP PR GAP 1 and the pinch roll GAP GR GAP 2. The disadvantages of such a solution are as follows:

(1) after the roll GAP PR GAP 1 of the inlet pinch roll is reduced, the impact on the inlet pinch roll when a plate blank passes through the roll GAP PR GAP 1 is increased, and the quality of the roll surface and the service life of mechanical equipment are influenced;

(2) referring to fig. 6, if the slab slips and stops before passing through the inlet pinch roll, the roll GAPs of the inlet pinch roll and the outlet pinch roll are reduced to the secondary roll GAP GR GAP 2, one possibility is that the slab is blocked at the inlet pinch roll and cannot advance, and the other possibility is that impact on the roll is increased when the slab passes through, and the quality of the roll surface and the service life of mechanical equipment are also affected.

In conclusion, in the actual process production process, how to change the control mode of the inlet pinch roll, the inlet pinch roll and the outlet pinch roll of the width fixing machine, the slip fault of the plate blank in the width fixing machine is reduced, the damage to the roll surface and mechanical equipment when the plate blank enters steel is avoided, and the problem to be solved urgently in the actual production process is solved.

Disclosure of Invention

The invention aims to provide a method for preventing a width fixing machine from slipping. The invention aims to reduce the slip fault of the slab in the fixed width machine and the damage to the roll surface and mechanical equipment when the slab enters steel by adding detection equipment aiming at the actual position of the slab in the fixed width machine and changing the control mode of an inlet pinch roll, an inlet compression roll and an outlet compression roll of the fixed width machine.

The technical scheme of the invention is as follows: the method for preventing the width fixing machine from slipping is characterized by comprising the following steps:

1) along the advancing direction of the plate blank, arranging No. 1 detection equipment for the actual position of the plate blank behind an inlet pinch roll of the width fixing machine, wherein the detection equipment is used for detecting whether the plate blank passes through the inlet pinch roll;

2) along the advancing direction of the plate blank, behind the outlet pressing roller of the width fixing machine, detecting equipment No. 2 of the actual position of the plate blank is arranged and used for detecting whether the plate blank passes through the outlet pressing roller or not;

3) drawing steel by a heating furnace, and issuing the theoretical thickness H of the plate blank to a basic automation computer of a width setting machine by a process control computer;

4) respectively calculating a roll GAP PR GAP 1 of an inlet pinch roll and a primary roll GAP GR GAP 1 of an inlet compression roll and an outlet compression roll by a basic automatic computer of the width fixing machine according to the theoretical thickness H of the plate blank;

5) when the slab passes through the inlet pinch roll, if the pressure of the inlet pinch roll is equal to 50KN, a basic automation computer of the width fixing machine judges that the slab bites into the inlet pinch roll, and the position control of the inlet pinch roll is switched to pressure control;

6) if the pressure of the inlet pinch roll is always less than 50KN, but the slab is detected by No. 1 detection equipment at the actual position of the slab, and a basic automation computer of the width fixing machine judges that the slab passes through the inlet pinch roll, the position control of the inlet pinch roll is switched to the pressure control;

7) calculating the position of the plate blank by a basic automation computer of the width fixing machine, and calculating a secondary roll GAP GR GAP 2 of an inlet compression roller and an outlet compression roller by the basic automation computer of the width fixing machine after the plate blank passes through the outlet compression roller;

8) if the actual thickness h of the plate blank is larger than the roll gap between the inlet pressing roll and the outlet pressing roll, and when the pressure of the inlet pressing roll and the pressure of the outlet pressing roll are equal to 50KN, the basic automation computer of the width fixing machine judges that the plate blank passes through the outlet pressing roll, and the position control of the inlet pressing roll and the position control of the outlet pressing roll are switched to the pressure control;

9) if the pressure of the inlet compression roller and the pressure of the outlet compression roller are always less than 50KN, but the detection equipment of the actual position No. 2 of the slab detects the slab, and the basic automation computer of the width fixing machine judges that the slab passes through the outlet compression roller, the position control of the inlet compression roller and the position control of the outlet compression roller are switched to the pressure control;

10) and (6) ending.

Specifically, the calculation formula of the roll GAP PR GAP 1 of the inlet pinch roll is as follows:

PR GAP 1 ═ H-a1 formula 1

Wherein H is the theoretical thickness of the plate blank; a1 ═ 10 mm.

Specifically, the calculation formula of the primary roll GAP GR GAP 1 of the inlet pinch roll and the outlet pinch roll is as follows:

GR GAP 1 ═ H + B1 equation 2

Wherein H is the theoretical thickness of the plate blank; b1 ═ 40 mm.

Specifically, the calculation formula of the secondary roll GAP GR GAP 2 of the inlet pinch roll and the outlet pinch roll is as follows:

GR GAP 2-H-B2 equation 3

Wherein H is the theoretical thickness of the plate blank; b2 ═ 10 mm.

Specifically, the detection device for the actual position 1 of the slab and the detection device for the actual position 2 of the slab are object position detection switches.

Further, the detection device for the actual position 1 of the slab and the detection device for the actual position 2 of the slab are mechanical or photoelectric position detection switches.

Furthermore, the detection device for the actual position 1 of the slab and the detection device for the actual position 2 of the slab are hot metal detectors.

According to the method for preventing the fixed width machine from slipping, the actual running position of the plate blank is obtained by respectively adding a plate blank actual position detection device behind an inlet pinch roll and an outlet pinch roll of the fixed width machine.

Compared with the prior art, the invention has the advantages that:

1. by adopting the technical scheme of the invention, the problem that the slab slips in the fixed-width machine due to inaccurate theoretical thickness H of the slab can be effectively reduced, and abnormal remelting of the slab is reduced;

2. after the technical scheme of the invention is adopted, the impact generated by reducing the roll gaps of the inlet pinch roll, the inlet compression roll and the outlet compression roll and the damage of the roll surface and mechanical equipment caused by the impact can be effectively avoided.

Drawings

FIG. 1 is a schematic view of the working principle of a sizing machine;

FIG. 2 is a schematic representation of the condition of the slab before it enters the inlet pinch rolls;

FIG. 3 is a prior art control flow diagram;

FIG. 4 is a schematic view of a slab passing over the pinch rollers;

FIG. 5 is a schematic view of the inlet pinch roll, inlet pinch roll and outlet pinch roll switching to pressure control;

FIG. 6 is a schematic view of the inlet and outlet pinch rollers after a secondary nip reduction;

FIG. 7 is a schematic view of the added slab actual position detection apparatus of the present invention;

fig. 8 is a control flow block diagram of the control method of the present invention.

In the figure, 1 is a plate blank, 2 is a module, 3 is a forward direction, 4 is a pinch roll, 5 is an inlet compression roll, 6 is an outlet compression roll, 7 is detection equipment for the actual position of the plate blank, 1 is detection equipment for the actual position of the plate blank, and 8 is detection equipment for the actual position of the plate blank, 2 is detection equipment for the actual position of the plate blank.

Detailed Description

The invention is further illustrated with reference to the following figures and examples.

Since the accurate position of the slab cannot be obtained, the prior art uses the impact of the slab on the inlet pinch roll to obtain the position of the slab.

The applicant discovers through a large amount of observation, analysis and tests that the purposes of reducing the slip fault of the slab in the width fixing machine and the damage to the roll surface and mechanical equipment when the slab enters steel can be achieved by only adding a slab actual position detection device behind an inlet pinch roll and an outlet pinch roll of the width fixing machine respectively and changing the control modes of the inlet pinch roll, the inlet pinch roll and the outlet pinch roll of the width fixing machine to ensure that the slab passes through the rolls and then is pressed down.

The technical scheme of the invention is as follows:

(1) newly adding equipment:

referring to fig. 7, a detection device 7 for detecting the actual position of the slab is added after the pinch roll 4 at the inlet of the width fixing machine, and a detection device 8 for detecting the actual position of the slab is added after the pinch roll 6 at the outlet of the width fixing machine.

The detection device No. 1 is used for detecting whether the plate blank passes through an inlet pinch roll or not; no. 2 check out test set is used for detecting whether the slab passes through export pinch roller.

(2) The control flow comprises the following steps:

referring to fig. 8, the control flow of the method for preventing the width fixing machine from slipping according to the present invention is as follows:

(1) starting;

(2) drawing steel by a heating furnace, and issuing the theoretical thickness H of the plate blank to a basic automation computer of a width setting machine by a process control computer;

(3) respectively calculating a roll GAP PR GAP 1 of an inlet pinch roll 4, a primary roll GAP GR GAP 1 of an inlet compression roll 5 and a primary roll GAP GR GAP 1 of an outlet compression roll 6 by a basic automatic computer of the width fixing machine according to the theoretical thickness H of the plate blank and a formula 1 and a formula 2;

PR GAP 1 ═ H-a1 formula 1

GR GAP 1 ═ H + B1 equation 2

(4) When the slab passes through the inlet pinch roll, if the actual thickness h of the slab is larger than the roll gap of the inlet pinch roll, the slab can generate certain impact on the inlet pinch roll, and the pressure of the inlet pinch roll can rise; when the pressure > is 50KN, the basic automation computer of the width fixing machine judges that the slab bites into the inlet pinch roll, and the position control of the inlet pinch roll is switched to the pressure control;

(5) if the pressure of the inlet pinch roll is less than 50KN all the time, but the No. 1 detection device detects the slab, and the basic automation computer of the width fixing machine judges that the slab passes through the inlet pinch roll, the position control of the inlet pinch roll is switched to the pressure control;

(6) calculating the position of the plate blank by a basic automation computer of the width fixing machine, and calculating a secondary roll GAP GR GAP 2 of an inlet pressing roll and an outlet pressing roll by the basic automation computer of the width fixing machine according to a formula 3 after the plate blank passes through the outlet pressing roll;

GR GAP 2-H-B2 equation 3

(7) If the actual thickness h of the plate blank is larger than the roll gaps of the inlet pressing roll and the outlet pressing roll, the pressure of the inlet pressing roll and the pressure of the outlet pressing roll can rise; when the pressure > is 50KN, the basic automation computer of the width fixing machine judges that the plate blank passes through the outlet pinch roller, and the position control of the inlet pinch roller and the outlet pinch roller is switched to the pressure control;

(8) if the pressure of the inlet compression roller and the outlet compression roller is always less than 50KN, but the No. 2 detection device detects the plate blank, and the basic automation computer of the width fixing machine judges that the plate blank passes through the outlet compression roller, the inlet compression roller and the outlet compression roller are switched from position control to pressure control;

(9) and (6) ending.

Wherein: h, theoretical thickness of a plate blank; h-the actual thickness of the slab; a1 ═ 10 mm; b1 ═ 40 mm; b2 ═ 10 mm.

The technical scheme of the invention is adopted on a production line of a fixed width machine of a production line of a certain hot rolling plant, and the No. 1 and No. 2 detection devices adopt a DELTA DC2030 HMD hot metal detector with the measurement range of 400 ℃ and 1500 ℃.

Through actual trial operation and test, the design purpose and the expected technical effect of the device are completely achieved.

According to the technical scheme, the invention aims to reduce the slip fault of the slab in the fixed width machine and the damage to the roll surface and mechanical equipment when the slab enters steel are achieved by adding the slab actual position detection equipment in the fixed width machine and changing the control modes of the inlet pinch roll, the inlet compression roll and the outlet compression roll of the fixed width machine.

The invention can be widely applied to the field of production process control of the hot rolling width fixing machine.