CN103451588A - Control method for edge baffle plate of galvanizing unit - Google Patents

Abstract

A control method for edge baffle plates of a galvanizing unit belongs to the control field. A transmission side and an operation side of strip steel are respectively provided with a set of non-contact edge baffle plate control assembly; an actual width value of the strip steel passing through an air knife framework is tested; a non-contact mode is employed to detect position discrepancy of strip steel edges; when a signal indicating the strip steel weld is 15 s away from the air knife is received, the air knife PLC controls the edge baffle plates to open from the middle to two sides to a specified position; when the signal indicating the strip steel weld is at the air knife is received, the air knife PLC carries out closing position control on the edge baffle plates; discrepancy of the actual position of the strip steel edges is controlled and calculated by a PID regulator and used as a set speed value of a servo motor for automatic correction of positions of the edge baffle plates. Therefore, the technological requirement of a prescribed gap from the ends of the sides of the baffle plates to the external rims of the strip steel is ensured; and automatic control mode on the edge baffle plates can be realized when the strip steel weld passes through the air knife. The method provided by the invention can be widely applied to the field of production control of air knife equipment of a zinc pan in cold rolling industry.

Description

A kind of control method of pot galvanize unit edge dam

Technical field

The invention belongs to control field, relate in particular to a kind of control method for cold rolling hot dip galvanizing unit zinc pot air knife edge dam.

Background technology

As the pot galvanize unit of cold rolling mill production high added value weight product, undertaking the production task that contains all cold rolling battle wagon plates.

In whole piece unit production technique, zinc pot equipment intact, to directly affect cold-rolling galvanization plate quality good or not, high-precision edge dam position control, can effectively eliminate the extension zinc of steel edge portion appearance or thicken defect problem (band steel zinc layer control accuracy is in+10%) simultaneously.

During normal production, operating band steel outward flange and baffle plate side end processing requirement 2-3mm, but traditional edge dam control techniques adopts the contact master mode, this master mode is owing to not equipping the equipment such as linear transducer, servomotor and EMG (strip edge edge detector), the control mode that it can only adopt edge dam to contact with the strip edge edge.

In actual application, when band steel weld seam, through air knife the time, the problem often occurred mainly contains:

When 1, band steel weld seam is crossed air knife, edge dam adopts the contact master mode, operating band steel outward flange and baffle plate side end 2-3mm processing requirement when this pattern can not meet normal production, thus the mass defects such as the extension zinc that differs in size or edge thickening appear in the steel edge portion after zinc-plated;

2, for guaranteeing that qualified product dispatch from the factory, the extension zinc that galvanized steel limit section is occurred or while thickening defect problem ，Xia road production process, adopt many excision steel edge portion width, consequently increase material loss, affected the production of units lumber recovery, caused the rising of the unit cost of production;

3, for overcoming the deficiency on prior art, the production operation personnel take manually closely adjust operation steel edge portion and baffle plate side play by rule of thumb usually temporarily, because the operating environment temperature is high, zinc pot zinc liquid temperature reaches 460 ° of C left and right, have certain potential safety hazard during operation, hand labor intensity is larger;

4, the air knife edge dam adopts contact to control function, main manifestations is for when band steel weld seam is crossed air knife, after edge dam is opened automatically, need the operative employee according to the on-the-spot practical situation edge dam that manually closes, greatly strengthen operative employee's labour intensity, also be unfavorable for the control of the coating quality of steel edge portion.

Summary of the invention

Technical problem to be solved by this invention is to provide a kind of control method of pot galvanize unit edge dam, it adopts strip edge edge detector, by the non-contact measurement pattern, measure steel edge portion position deviation value, the mass defects such as the extension zinc differed in size that the steel edge portion after zinc-plated occurs or edge thickening have effectively been controlled, improved to a certain extent the lumber recovery of unit, improved operative employee's operating environment, both reduce operative employee's labour intensity, be conducive to again the Coating quality control of steel edge portion.

Technical scheme of the present invention is: the control method that a kind of pot galvanize unit edge dam is provided, comprise that air knife PLC is controlled the opening and closing of edge dam, make edge dam open or close the position of appointment from middle past both sides according to the instruction of air knife PLC, it is characterized in that:

1) according to production technique with the product parameters of steel, preset the safety clearance set(ting)value that a weld seam is crossed air knife;

2) respectively install one for detection of the linear transducer with steel developed width value in air knife framework both sides, the band steel developed width value by the air knife framework is detected;

3) a strip edge edge detector is installed on each edge dam, is adopted non-contacting mode to detect steel edge portion position deviation value;

4) on each edge dam frame, servomotor and cross moving track are set, described servomotor, according to the air knife PLC control signal received, drives edge dam to do and the transverse shifting vertical with the steel direction along cross moving track;

5) after receiving the first band steel position signal with 15 seconds signals of steel welding seam distance air knife that machine set PLC sends, air knife PLC controls edge dam from the middle first location that is opened to appointment toward both sides;

6) after the second band steel position signal at air knife, edge dam is carried out to off-position control with the steel weld seam when what air knife PLC received that machine set PLC sends;

7) by being arranged on the strip edge edge detector on edge dam, detect the deviate of steel edge portion physical location;

8) deviate of steel edge portion physical location, after the PID setter is controlled calculating, as the speed preset value of servomotor, is revised the position of edge dam automatically, thereby guarantees the processing requirement of baffle plate side end distance with steel outward flange 2-3mm;

9) by strip edge edge detector to the detection of steel edge portion actual deviation position and automatic control that edge dam is opened, closed, when realization is crossed air knife with the steel weld seam to the automatic control mode of edge dam, assurance remains on the processing requirement in the range of set value of safety clearance with the spacing between steel outward flange and baffle plate side, effectively control steel edge portion and hang the defect of zinc and edge thickening, improve the coating quality of steel edge portion, reduce the steel edge portion excision amount of lower road production process, improve the lumber recovery of unit.

Further, the position signal output terminal of described linear transducer and strip edge edge detector is connected with the I/O port of air knife PLC, and the control signal input terminus of described stepper-motor is connected with the I/O port of air knife PLC; Described cross moving track is directive slide track, lead screw guide rails or gear-rack gear guide rail; Described linear transducer, strip edge edge detector, cross moving track and servomotor, form a set of contactless edge dam control unit.

Further, at back side and the fore side of pot galvanize unit band steel, a set of described contactless edge dam control unit is set respectively.

Concrete, when described edge dam execution is opened to control automatically, the strip width value that the linear transducer autoscan measures, carry out alignment processing by following relation:

For back side:

Width_DR(mm)=PBW987

In formula: Width_DR: be back side strip width value;

PBW987: be the analog input value of back side linear transducer;

For fore side:

Width_OP(mm)=PBW991

In formula: Width_OP: be fore side strip width value;

PBW991: be the analog input value of fore side linear transducer.

Concrete, when described edge dam is opened to the first location of appointment from middle past both sides, the open position set-point of described servomotor is calculated according to following relationship:

For back side:

$\mathrm{POS}\_\mathrm{REF}\_\mathrm{OPEN}\_\mathrm{DR}=\mathrm{Width}\_\mathrm{DR}+\frac{\mathrm{Width}\_\mathrm{trail}-\mathrm{Width}\_\mathrm{<figure-callout\; id="2"\; label="lead"\; filenames="HDA00001711773500021.png"\; state="\{\{state\}\}">lead</figure-callout>}}{2}+S\_\mathrm{gap}\_\mathrm{weld}$

In formula: POS_REF_OPEN_DR: be back side servomotor position set-point;

Width_DR: be back side strip width value;

Width_trail: for upper computer issues the width value of rear row band steel;

Width_lead: for upper computer issues in advance the width value with steel;

S_gap_weld: weld seam is crossed air knife safety clearance value;

For fore side:

$\mathrm{POS}\_\mathrm{REF}\_\mathrm{OPEN}\_\mathrm{OP}=\mathrm{Width}\_\mathrm{OP}+\frac{\mathrm{Width}\_\mathrm{trail}-\mathrm{Width}\_\mathrm{<figure-callout\; id="2"\; label="lead"\; filenames="HDA00001711773500021.png"\; state="\{\{state\}\}">lead</figure-callout>}}{2}+S\_\mathrm{gap}\_\mathrm{weld}$

In formula: POS_REF_OPEN_OP: be back side servomotor position set-point;

Width_OP: be fore side strip width value;

Width_trail: for upper computer issues the width value of rear row band steel;

Width_lead: for upper computer issues in advance the width value with steel;

S_gap_weld: weld seam is crossed air knife safety clearance value;

The calculating of its servomotor position actual value is pressed the row expression formula and is calculated:

For back side:

$\mathrm{POS}\_\mathrm{ACT}\_\mathrm{DR}=\frac{\mathrm{PZD}\_\mathrm{DR}\_\mathrm{IN}}{\mathrm{<figure-callout\; id="1"\; label="K"\; filenames="HDA00001711773500021.png"\; state="\{\{state\}\}">K</figure-callout>}1}$

In formula: POS_ACT_DR: be the actual value of back side servomotor;

PZD_DR_IN: be the input digital quantity of back side servomotor;

K1: transformation constant, this unit is 2.091*10 ⁵, unit is 1/mm;

For fore side:

$\mathrm{POS}\_\mathrm{ACT}\_\mathrm{OP}=\frac{\mathrm{PZD}\_\mathrm{OP}\_\mathrm{IN}}{\mathrm{<figure-callout\; id="1"\; label="K"\; filenames="HDA00001711773500021.png"\; state="\{\{state\}\}">K</figure-callout>}1}$

In formula: POS_ACT_OP: be the actual value of fore side servomotor;

PZD_OP_IN: be the input digital quantity of fore side servomotor;

K1: transformation constant, this unit is 2.091*10 ⁵, unit is 1/mm.

After described air knife PLC receives the first band steel position signal of 15 seconds signals of machine set PLC band steel welding seam distance air knife, control the driven by servomotor edge dam and move laterally, automatically be opened to the first location that calculates set-point by above-mentioned expression formula.

Further, after described air knife PLC receives the first band steel position signal of 15 seconds signals of machine set PLC band steel welding seam distance air knife, control the driven by servomotor edge dam and move laterally, automatic high speed is opened to first location.

The high speed speed setting value of its described control servomotor is 300RPM to the maximum.

Concrete, when described edge dam is carried out to off-position control, the off-position set-point of servomotor is calculated according to following relationship:

For back side:

$\mathrm{POS}\_\mathrm{REF}\_\mathrm{CLOSE}\_\mathrm{DR}=\mathrm{Width}\_\mathrm{DR}+\frac{\mathrm{Width}\_\mathrm{trail}-\mathrm{Width}\_\mathrm{<figure-callout\; id="2"\; label="lead"\; filenames="HDA00001711773500021.png"\; state="\{\{state\}\}">lead</figure-callout>}}{2}+\mathrm{OFFSET}\_\mathrm{CLOSE}$

In formula: POS_REF_CLOSE_DR: be back side servomotor position set-point;

Width_DR: be back side strip width value;

Width_trail: the rear row strip width value issued for upper computer;

Width_lead: the value of strip width in advance issued for upper computer;

OFFSET_CLOSE: be the given deviate of off-position;

For fore side:

$\mathrm{POS}\_\mathrm{REF}\_\mathrm{CLOSE}\_\mathrm{OP}=\mathrm{Width}\_\mathrm{OP}+\frac{\mathrm{Width}\_\mathrm{trail}-\mathrm{Width}\_\mathrm{<figure-callout\; id="2"\; label="lead"\; filenames="HDA00001711773500021.png"\; state="\{\{state\}\}">lead</figure-callout>}}{2}+\mathrm{OFFSET}\_\mathrm{CLOSE}$

In formula: POS_REF_CLOSE_OP: be fore side servomotor position set-point;

Width_OP: be back side strip width value;

Width_trail: the width value of the rear row band steel issued for upper computer;

Width_lead: for upper computer issue in advance with the width value of steel;

OFFSET_CLOSE: be the given deviate of off-position;

After air knife PLC receives the second band steel position signal of machine set PLC band steel weld seam at air knife, control the driven by servomotor edge dam and move laterally, make edge dam automatically be closed to the off-position that calculates set-point by above-mentioned expression formula.

Further, after described air knife PLC receives the second band steel position signal of machine set PLC band steel weld seam at air knife, control the driven by servomotor edge dam and move laterally, make the automatic low speed of edge dam be closed to off-position.

The low rotation speed set(ting)value minimum of its described control servomotor is 100RPM.

Concrete, when carrying out described automatic correction edge dam position, the band steel side-play amount that strip edge edge detector detects is carried out alignment processing by following relation:

For back side:

Y_EMG_DR=(PIW1086-OFFSET_DR)/100

In formula: Y_EMG_DR: for back side detects band steel side-play amount;

PIW1086: be strip edge edge detector analog input digital quantity;

OFFSET_DR: be strip edge edge detector zero offset set(ting)value after back side edge dam contact zones steel;

For fore side:

Y_EMG_OP=（PIW1084-OFFSET_OP）/100

In formula: Y_EMG_OP: for fore side detects band steel side-play amount;

PIW1084: be strip edge edge detector analog input digital quantity;

OFFSET_OP: be strip edge edge detector zero offset set(ting)value after fore side edge dam contact zones steel.

Concrete, when carrying out described automatic correction edge dam position, the speed of described servomotor operation set-point is calculated according to following relationship:

In formula: SPEED_SM_DR: be back side servomotor speed preset value;

SPEED_SM_OP: be fore side servomotor speed preset value;

SET_VAL: strip edge edge and edge dam gap set(ting)value;

Y_EMG_DR: for back side detects band steel side-play amount;

K _p: be the proportional gain value of setter;

K _d: be the differential gain value of setter;

K: be the control conversion factor of servomotor;

LMN_OFF: be servomotor deviation from the index value value;

Normally in service at unit, detect and obtain being with the steel side-play amount by strip edge edge detector, the servomotor speed preset value calculated according to above-mentioned expression formula, control servomotor and automatically adjust the position of edge dam, thereby guarantee that gap between strip edge edge and edge dam is within the processing requirement scope of setting.

The preferable range that its described weld seam is crossed air knife safety clearance value S_gap_weld is: 150-250mm.

The preferable range of the deviate OFFSET_CLOSE that its described off-position is given is: 5-15mm.

The proportional gain value K of its described setter _ppreferable range be: between 1-1.5; The differential gain value K of described setter _dpreferable range be: between 0.001-0.002.

Compared with the prior art, advantage of the present invention is:

1. adopt the non-contact measurement pattern to measure steel edge portion position deviation value, overcome in the past edge dam and adopted contact master mode strip edge edge and baffle plate side end control accuracy can not meet the drawback of processing requirement, thereby effectively controlled the mass defects such as the extension zinc differed in size of the steel edge portion appearance after zinc-plated or edge thickening;

2., after effectively having controlled the mass defects such as the extension zinc differed in size that the steel edge portion after zinc-plated occurs or edge thickening, the more steel edge portion of the unnecessary excision of next procedure, improved the lumber recovery of unit to a certain extent;

3. changed in the past the operative employee by rule of thumb at operating environment poor place adjust steel edge portion and the side-play drawback of baffle plate, automatic control has been realized in steel edge portion and baffle plate side play, has improved to a certain extent operative employee's operating environment;

4. avoided in the past the edge dam closing control to need manually-operated drawback, edge dam close the position control that also adopts servomotor, reduced operative employee's labour intensity, be conducive to again the Coating quality control of steel edge portion;

5. the technical program, except improving quality product and improve unit operation throughput, has certain pushing effect for eliminating the potential safety hazard existed in production operation, has application value preferably.

The accompanying drawing explanation

Fig. 1 is control method block diagram of the present invention;

Fig. 2 is the schematic diagram of structure between the contactless edge dam control unit of the present invention and baffle plate.

In figure, 1 is the high temperature zinc pot, and 2 is zinc pot liquid level, and 3 is the band steel, and 4 is baffle plate, and 5 is linear transducer, and 6 is cross moving track, and 7 is strip edge edge detector, and 8 is servomotor, and 9 is leading screw.

Embodiment

Below in conjunction with drawings and Examples, the present invention will be further described.

In Fig. 1, the invention provides a kind of control method of pot galvanize unit edge dam, comprise that air knife PLC is controlled the opening and closing of edge dam, make edge dam open or close the position of appointment from middle past both sides according to the instruction of air knife PLC, it is characterized in that:

1) according to production technique with the product parameters of steel, preset the safety clearance set(ting)value that a weld seam is crossed air knife;

2) respectively install one for detection of the linear transducer with steel developed width value in air knife framework both sides, the band steel developed width value by the air knife framework is detected;

3) a strip edge edge detector is installed on each edge dam, is adopted non-contacting mode to detect steel edge portion position deviation value;

4) on each edge dam frame, servomotor and cross moving track are set, described servomotor, according to the air knife PLC control signal received, drives edge dam to do and the transverse shifting vertical with the steel direction along cross moving track;

5) after receiving the first band steel position signal with 15 seconds signals of steel welding seam distance air knife that machine set PLC sends, air knife PLC controls edge dam from the middle first location that is opened to appointment toward both sides;

6) after the second band steel position signal at air knife, edge dam is carried out to off-position control with the steel weld seam when what air knife PLC received that machine set PLC sends;

7) by being arranged on the strip edge edge detector on edge dam, detect the deviate of steel edge portion physical location;

8) deviate of steel edge portion physical location, after the PID setter is controlled calculating, as the speed preset value of servomotor, is revised the position of edge dam automatically, thereby guarantees the processing requirement of baffle plate side end distance with steel outward flange 2-3mm;

9) by strip edge edge detector to the detection of steel edge portion actual deviation position and automatic control that edge dam is opened, closed, when realization is crossed air knife with the steel weld seam to the automatic control mode of edge dam, assurance remains on the processing requirement in the range of set value of safety clearance with the spacing between steel outward flange and baffle plate side, effectively control steel edge portion and hang the defect of zinc and edge thickening, improve the coating quality of steel edge portion, reduce the steel edge portion excision amount of lower road production process, improve the lumber recovery of unit.

In Fig. 2, in technical scheme of the present invention, this edge dam non-contact control system comprises back side and fore side two cover Controlling System,

Every cover Controlling System is comprised of linear transducer, servomotor and strip edge edge detector (being designated hereinafter simply as EMG).

The position signal output terminal of described linear transducer and strip edge edge detector and air knife PLC(programmable logic controller, lower with) the I/O port connect.

The control signal input terminus of described stepper-motor is connected with the I/O port of air knife PLC.

Described cross moving track is directive slide track, lead screw guide rails or gear-rack gear guide rail.

In figure, 1 is the high temperature zinc pot, and 2 is zinc pot liquid level, and 3 is the band steel, and 4 is baffle plate, and 5 is linear transducer, and 6 is cross moving track, and 7 is strip edge edge detector, and 8 is servomotor, and 9 is leading screw.

Because machinery and the Controlling System of baffle plate is existing apparatus, its concrete structure and course of action are no longer narrated at this.

In technique scheme, servomotor, linear transducer and strip edge edge detector are commercially available prod, the standard application scheme that those skilled in the art all can provide according to its product description and manufacturer, learn its specific works principle and connection scheme, therefore also no longer narrate its annexation and course of action at this.

The present invention adopts the non-contact measurement pattern to measure steel edge portion position deviation value, having overcome edge dam in the past adopts contact master mode strip edge edge and baffle plate side end control accuracy can not meet the drawback of processing requirement, thereby the mass defects such as the extension zinc differed in size that the steel edge portion after zinc-plated occurs or edge thickening have effectively been controlled, improved to a certain extent the lumber recovery of unit, automatic control has been realized in steel edge portion and baffle plate side play, improved to a certain extent operative employee's operating environment, reduced operative employee's labour intensity, the Coating quality control that is conducive to again steel edge portion.

Embodiment:

The cold rolling 1730 pot galvanize units of certain Iron And Steel Company five are as a case study on implementation of patent of the present invention.

Its edge dam control techniques adopts the Untouched control pattern, and its concrete control program is referring to shown in Fig. 1, Fig. 2.

In the present embodiment: the width with steel is in advance: 1464mm, the width of rear row band steel is: 1574mm.

One, edge dam is opened the control section explanation automatically:

The calculating of the strip width value that 1, the autoscan of linear transducer measures:

DR (back side):

Width_DR(mm)=PBW987----------(1)

In formula: Width_DR: be back side strip width value, unit is mm.

PBW987: be the analog input value of the linear transducer of back side, its digital quantity that is 16 systems.

OP (fore side):

Width_OP(mm)=PBW991----------(2)

In formula: Width_OP: be fore side strip width value, unit is mm.

PBW991: be the analog input value of the linear transducer of fore side, the digital quantity that unit is 16 systems.

In the present embodiment, the strip width with steel is in advance: 1464mm is recorded by the linear transducer autoscan.

Back side strip width: Width_DR (mm)=PBW987=2DA (H)=730mm.

Fore side strip width: Width_OP (mm)=PBW991=2DE (H)=734mm.

2, the calculating of the open position set-point of servomotor:

$\mathrm{POS}\_\mathrm{REF}\_\mathrm{OPEN}\_\mathrm{DR}=\mathrm{Width}\_\mathrm{DR}+\frac{\mathrm{Width}\_\mathrm{trail}-\mathrm{Width}\_\mathrm{<figure-callout\; id="2"\; label="lead"\; filenames="HDA00001711773500021.png"\; state="\{\{state\}\}">lead</figure-callout>}}{2}+S\_\mathrm{gap}\_\mathrm{weld}----\left(3\right)$

In formula: POS_REF_OPEN_DR: be back side servomotor position set-point, unit is mm.

Width_DR: be back side strip width value, unit is mm.

Width_trail: for upper computer issues the width value of rear row band steel, unit is mm.

Width_lead: for upper computer issues in advance with the width value of steel, unit is mm.

S_gap_weld: it is mm that weld seam is crossed air knife safety clearance Zhi， unit.The preferential scope of this value is: 150-250mm.

$\mathrm{POS}\_\mathrm{REF}\_\mathrm{OPEN}\_\mathrm{OP}=\mathrm{Width}\_\mathrm{OP}+\frac{\mathrm{Width}\_\mathrm{trail}-\mathrm{Width}\_\mathrm{<figure-callout\; id="2"\; label="lead"\; filenames="HDA00001711773500021.png"\; state="\{\{state\}\}">lead</figure-callout>}}{2}+S\_\mathrm{gap}\_\mathrm{weld}----\left(4\right)$

In formula: POS_REF_OPEN_OP: be back side servomotor position set-point, unit is mm.

Width_OP: be back side strip width value, unit is mm.

Width_trail: for upper computer issues the width value of rear row band steel, unit is mm.

Width_lead: for upper computer issues in advance with the width value of steel, unit is mm.

S_gap_weld: it is mm that weld seam is crossed air knife safety clearance Zhi， unit.The preferential scope of this value is: 150-250mm.

In the present embodiment, the strip width with steel is in advance: 1464mm, the width of rear row band steel is 1574mm.S_gap_weld: weld seam is crossed air knife safety clearance value and is preferably: 200mm.

As calculated: the position set-point of servomotor is:

$\mathrm{POS}\_\mathrm{REF}\_\mathrm{OPEN}\_\mathrm{DR}=\mathrm{Width}\_\mathrm{DR}+\frac{\mathrm{Width}\_\mathrm{trail}-\mathrm{Width}\_\mathrm{<figure-callout\; id="2"\; label="lead"\; filenames="HDA00001711773500021.png"\; state="\{\{state\}\}">lead</figure-callout>}}{2}+S\_\mathrm{gap}\_\mathrm{weld}$

$=730+(1574-1464)/2+200=985\mathrm{mm}.$

$\mathrm{POS}\_\mathrm{REF}\_\mathrm{OPEN}\_\mathrm{OP}=\mathrm{Width}\_\mathrm{OP}+\frac{\mathrm{Width}\_\mathrm{trail}-\mathrm{Width}\_\mathrm{<figure-callout\; id="2"\; label="lead"\; filenames="HDA00001711773500021.png"\; state="\{\{state\}\}">lead</figure-callout>}}{2}+S\_\mathrm{gap}\_\mathrm{weld}$

$=734+(1574-1464)/2+200=989\mathrm{mm}.$

3, the calculating of servomotor position actual value:

$\mathrm{POS}\_\mathrm{ACT}\_\mathrm{DR}=\frac{\mathrm{PZD}\_\mathrm{DR}\_\mathrm{IN}}{K1}---\left(5\right)$

In formula: POS_ACT_DR: be the actual value of back side servomotor, unit is mm.

PZD_DR_IN: be the input digital quantity of back side servomotor.

K1: transformation constant, this unit is 2.091*10 ⁵, unit is 1/mm.

$\mathrm{POS}\_\mathrm{ACT}\_\mathrm{OP}=\frac{\mathrm{PZD}\_\mathrm{OP}\_\mathrm{IN}}{K1}---\left(6\right)$

In formula: POS_ACT_OP: be the actual value of back side servomotor, unit is mm.

PZD_OP_IN: be the input digital quantity of back side servomotor.

K1: transformation constant, this unit is 2.091*10 ⁵, unit is 1/mm.

In the present embodiment, the strip width with steel is in advance: 1464mm, the width of rear row band steel be 1574mm as calculated: the position actual value of servomotor is:

$\mathrm{POS}\_\mathrm{ACT}\_\mathrm{DR}=\frac{\mathrm{PZD}\_\mathrm{DR}\_\mathrm{IN}}{\mathrm{<figure-callout\; id="1"\; label="K"\; filenames="HDA00001711773500021.png"\; state="\{\{state\}\}">K</figure-callout>}1}=\frac{205963500}{2.091*100000}=985\mathrm{mm}$

$\mathrm{POS}\_\mathrm{ACT}\_\mathrm{OP}=\frac{\mathrm{PZD}\_\mathrm{OP}\_\mathrm{IN}}{\mathrm{<figure-callout\; id="1"\; label="K"\; filenames="HDA00001711773500021.png"\; state="\{\{state\}\}">K</figure-callout>}1}=\frac{206799900}{2.091*100000}=989\mathrm{mm}$

After air knife PLC receives 15 seconds signals of machine set PLC band steel welding seam distance air knife, control servomotor make edge dam automatically fast (the utmost dispatch set(ting)value is 300RPM) be opened to the position set-point that formula (3) and (4) calculate.

Two, the automatic closing control of edge dam partly illustrates:

The calculating of the off-position set-point of servomotor:

$\mathrm{POS}\_\mathrm{REF}\_\mathrm{CLOSE}\_\mathrm{DR}=\mathrm{Width}\_\mathrm{DR}+\frac{\mathrm{Width}\_\mathrm{trail}-\mathrm{Width}\_\mathrm{<figure-callout\; id="2"\; label="lead"\; filenames="HDA00001711773500021.png"\; state="\{\{state\}\}">lead</figure-callout>}}{2}+\mathrm{OFFSET}\_\mathrm{CLOSE}$

$---\left(7\right)$

In formula: POS_REF_CLOSE_DR: be back side servomotor position set-point, unit is mm.

Width_DR: be back side strip width value, unit is mm.

Width_trail: be the rear row strip width value that upper computer issues, unit is mm.

Width_lead: be the value of strip width in advance that upper computer issues, unit is mm.

OFFSET_CLOSE: be the given deviate of off-position, unit is mm, and the preferential scope of this value is: 5-15mm

$\mathrm{POS}\_\mathrm{REF}\_\mathrm{CLOSE}\_\mathrm{OP}=\mathrm{Width}\_\mathrm{OP}+\frac{\mathrm{Width}\_\mathrm{trail}-\mathrm{Width}\_\mathrm{<figure-callout\; id="2"\; label="lead"\; filenames="HDA00001711773500021.png"\; state="\{\{state\}\}">lead</figure-callout>}}{2}+$

$\mathrm{OFFSET}\_\mathrm{CLOSE}---\left(8\right)$

In formula: POS_REF_CLOSE_OP: be back side servomotor position set-point, unit is mm.

Width_OP: be back side strip width value, unit is mm.

Width_trail: the width value of the rear row band steel issued for upper computer, unit is mm.

Width_lead: for upper computer issue in advance with the width value of steel, unit is mm.

OFFSET_CLOSE: be the given deviate of off-position, unit is mm, and the preferential scope of this value is: 5-15mm.

In the present embodiment, the strip width with steel is in advance: 1464mm, the width of rear row band steel is 1574mm.OFFSET_CLOSE: be the given deviate of off-position, this unit is preferably :-10mm.

The off-position set-point of servomotor is as calculated:

$\mathrm{POS}\_\mathrm{REF}\_\mathrm{CLOSE}\_\mathrm{DR}=\mathrm{Width}\_\mathrm{DR}+\frac{\mathrm{Width}\_\mathrm{trail}-\mathrm{Width}\_\mathrm{<figure-callout\; id="2"\; label="lead"\; filenames="HDA00001711773500021.png"\; state="\{\{state\}\}">lead</figure-callout>}}{2}+\mathrm{OFFSET}\_\mathrm{CLOSE}$

$=730+(1574-1464)/2-10=775\mathrm{mm}.$

$\mathrm{POS}\_\mathrm{REF}\_\mathrm{CLOSE}\_\mathrm{OP}=\mathrm{Width}\_\mathrm{OP}+\frac{\mathrm{Width}\_\mathrm{trail}-\mathrm{Width}\_\mathrm{<figure-callout\; id="2"\; label="lead"\; filenames="HDA00001711773500021.png"\; state="\{\{state\}\}">lead</figure-callout>}}{2}+\mathrm{OFFSET}\_\mathrm{CLOSE}$

$=734+(1574-1464)/2-10=779\mathrm{mm}.$

When air knife PLC receives machine set PLC band steel weld seam after signal, control servomotor and make the automatic low speed of edge dam (the minimum speed set(ting)value is 100RPM) be closed to the position set-point that formula (7) and (8) calculate.

Three, EMG (strip edge edge detector) band steel skew control section explanation:

1, the calculating of EMG (strip edge edge detector) back side band steel side-play amount:

Y_EMG_DR=(PIW1086-OFFSET_DR)/100-------------(9)

In formula: Y_EMG_DR: for back side detects band steel side-play amount, unit is: mm.

PIW1086: be EMG (strip edge edge detector) analog input digital quantity.

OFFSET_DR: be EMG (strip edge edge detector) zero offset set(ting)value after back side edge dam contact zones steel.

Back side zero offset value OFFSET_DR=-32 during edge dam contact zones steel edge

EMG (strip edge edge detector) back side analog input digital quantity value=-240.

As calculated: back side band steel side-play amount

Y_EMG_DR=(PIW1086-OFFSET_DR)/100＝（－240＋32）/100＝2.08mm。

2, the calculating of EMG (strip edge edge detector) fore side band steel side-play amount:

Y_EMG_OP=（PIW1084-OFFSET_OP）/100----------(10)

In formula: Y_EMG_OP: for fore side detects band steel side-play amount, unit is: mm.

PIW1084: be EMG (strip edge edge detector) analog input digital quantity.

OFFSET_OP: be EMG (strip edge edge detector) zero offset set(ting)value after fore side edge dam contact zones steel.

Fore side zero offset value OFFSET_OP=-480 during edge dam contact zones steel edge

EMG (strip edge edge detector) fore side analog input digital quantity value=-672.

As calculated: fore side band steel side-play amount:

Y_EMG_OP=（PIW1084-OFFSET_OP）/100＝（－672＋480）/100＝1.92mm。

3, servomotor speed operation set-point is calculated:

In formula: SPEED_SM_DR: be back side servomotor speed preset value, unit is RPM.

SPEED_SM_OP: be fore side servomotor speed preset value, unit is RPM.

SET_VAL: strip edge edge and edge dam gap set(ting)value, unit is: mm.

Y_EMG_DR: for back side detects band steel side-play amount, unit is: mm.

K _p: be the proportional gain value of setter.The preferential scope of this value is: between 1-1.5.

K _d: be the differential gain value of setter, the preferential scope of this value is: between 0.001-0.002.

K: be the control conversion factor of servomotor.

LMN_OFF: be servomotor deviation from the index value value, this unit is made as: 0.

As calculated: K _p: be the proportional gain value of setter, this unit is preferably 1.2,

K _d: be the differential gain value of setter, being preferably of this value: 0.001.

K: for this unit of control conversion factor of servomotor is preferably: 1.

SET_VAL: be strip edge edge and edge dam gap set(ting)value, this example is set as :-2.0mm.

Have:

Normally in service at unit, detect and obtain being with the steel side-play amount by EMG (strip edge edge detector), the servomotor speed preset value calculated according to formula (11) and (12), control servomotor and automatically adjust the position of edge dam, thereby guarantee that gap between strip edge edge and edge dam is within the processing requirement scope of setting.

Because the present invention adopts strip edge edge detector, by the non-contact measurement pattern, measure steel edge portion position deviation value, change strip edge edge and the baffle plate side end control accuracy that edge dam adopted the contact master mode to cause in the past and can not meet the drawback of processing requirement, thereby effectively controlled the mass defects such as the extension zinc differed in size of the steel edge portion appearance after zinc-plated or edge thickening; Improved to a certain extent the lumber recovery of unit.

Simultaneously, the technical program has realized automatic control to steel edge portion and baffle plate side play, eliminate edge dam closing control in the past and needed manually-operated drawback, edge dam close the position control that also adopts servomotor, improved to a certain extent operative employee's operating environment, reduce operative employee's labour intensity, be conducive to again the Coating quality control of steel edge portion.

The present invention can be widely used in the production control field of zinc pan gas cutter equipment in cold rolling industry.

Claims (15)

1. the control method of a pot galvanize unit edge dam, comprise that air knife PLC is controlled the opening and closing of edge dam, makes edge dam open or close the position of appointment from middle past both sides according to the instruction of air knife PLC, it is characterized in that:

1) according to production technique with the product parameters of steel, preset the safety clearance set(ting)value that a weld seam is crossed air knife;

2) respectively install one for detection of the linear transducer with steel developed width value in air knife framework both sides, the band steel developed width value by the air knife framework is detected;

3) a strip edge edge detector is installed on each edge dam, is adopted non-contacting mode to detect steel edge portion position deviation value;

4) on each edge dam frame, servomotor and cross moving track are set, described servomotor, according to the air knife PLC control signal received, drives edge dam to do and the transverse shifting vertical with the steel direction along cross moving track;

5) after receiving the first band steel position signal with 15 seconds signals of steel welding seam distance air knife that machine set PLC sends, air knife PLC controls edge dam from the middle first location that is opened to appointment toward both sides;

6) after the second band steel position signal at air knife, edge dam is carried out to off-position control with the steel weld seam when what air knife PLC received that machine set PLC sends;

7) by being arranged on the strip edge edge detector on edge dam, detect the deviate of steel edge portion physical location;

8) deviate of steel edge portion physical location, after the PID setter is controlled calculating, as the speed preset value of servomotor, is revised the position of edge dam automatically, thereby guarantees the processing requirement of baffle plate side end distance with steel outward flange 2-3mm;

9) by strip edge edge detector to the detection of steel edge portion actual deviation position and automatic control that edge dam is opened, closed, when realization is crossed air knife with the steel weld seam to the automatic control mode of edge dam, assurance remains on the processing requirement in the range of set value of safety clearance with the spacing between steel outward flange and baffle plate side, effectively control steel edge portion and hang the defect of zinc and edge thickening, improve the coating quality of steel edge portion, reduce the steel edge portion excision amount of lower road production process, improve the lumber recovery of unit.

2. according to the control method of pot galvanize unit edge dam claimed in claim 1, the position signal output terminal that it is characterized in that described linear transducer and strip edge edge detector is connected with the I/O port of air knife PLC, and the control signal input terminus of described stepper-motor is connected with the I/O port of air knife PLC; Described cross moving track is directive slide track, lead screw guide rails or gear-tooth bar drive rail; Described linear transducer, strip edge edge detector, cross moving track and servomotor, form a set of contactless edge dam control unit.

3. according to the control method of pot galvanize unit edge dam claimed in claim 2, it is characterized in that back side and fore side at pot galvanize unit band steel, a set of described contactless edge dam control unit is set respectively.

4. according to the control method of pot galvanize unit edge dam claimed in claim 1, it is characterized in that when described edge dam execution is opened to control automatically that the strip width value that the linear transducer autoscan measures is carried out alignment processing by following relation:

For back side:

Width_DR(mm)=PBW987

In formula: Width_DR: be back side strip width value;

PBW987: be the analog input value of back side linear transducer;

For fore side:

Width_OP(mm)=PBW991

In formula: Width_OP: be fore side strip width value;

PBW991: be the analog input value of fore side linear transducer.

5. according to the control method of pot galvanize unit edge dam claimed in claim 1, it is characterized in that the open position set-point of described servomotor is calculated according to following relationship when described edge dam is opened to the first location of appointment from middle past both sides:

For back side:

$\mathrm{POS}\_\mathrm{REF}\_\mathrm{OPEN}\_\mathrm{DR}=\mathrm{Width}\_\mathrm{DR}+\frac{\mathrm{Width}\_\mathrm{trail}-\mathrm{Width}\_\mathrm{lead}}{2}+S\_\mathrm{gap}\_\mathrm{weld}$

In formula: POS_REF_OPEN_DR: be back side servomotor position set-point;

Width_DR: be back side strip width value;

Width_trail: for upper computer issues the width value of rear row band steel;

Width_lead: for upper computer issues in advance the width value with steel;

S_gap_weld: weld seam is crossed air knife safety clearance value;

For fore side:

$\mathrm{POS}\_\mathrm{REF}\_\mathrm{OPEN}\_\mathrm{OP}=\mathrm{Width}\_\mathrm{OP}+\frac{\mathrm{Width}\_\mathrm{trail}-\mathrm{Width}\_\mathrm{lead}}{2}+S\_\mathrm{gap}\_\mathrm{weld}$

In formula: POS_REF_OPEN_OP: be back side servomotor position set-point;

Width_OP: be fore side strip width value;

Width_trail: for upper computer issues the width value of rear row band steel;

Width_lead: for upper computer issues in advance the width value with steel;

S_gap_weld: weld seam is crossed air knife safety clearance value;

The calculating of its servomotor position actual value is pressed the row expression formula and is calculated:

For back side:

$\mathrm{POS}\_\mathrm{ACT}\_\mathrm{DR}=\frac{\mathrm{PZD}\_\mathrm{DR}\_\mathrm{IN}}{K1}$

In formula: POS_ACT_DR: be the actual value of back side servomotor;

PZD_DR_IN: be the input digital quantity of back side servomotor;

K1: transformation constant, this unit is 2.091*10 ⁵, unit is 1/mm;

For fore side:

$\mathrm{POS}\_\mathrm{ACT}\_\mathrm{OP}=\frac{\mathrm{PZD}\_\mathrm{OP}\_\mathrm{IN}}{K1}$

In formula: POS_ACT_OP: be the actual value of fore side servomotor;

PZD_OP_IN: be the input digital quantity of fore side servomotor;

K1: transformation constant, this unit is 2.091*10 ⁵, unit is 1/mm;

After described air knife PLC receives the first band steel position signal of 15 seconds signals of machine set PLC band steel welding seam distance air knife, control the driven by servomotor edge dam and move laterally, automatically be opened to the first location that calculates set-point by above-mentioned expression formula.

6. according to the control method of the described pot galvanize unit of claim 1 or 5 edge dam, it is characterized in that after described air knife PLC receives the first band steel position signal of 15 seconds signals of machine set PLC band steel welding seam distance air knife, control the driven by servomotor edge dam and move laterally, automatic high speed is opened to first location.

7. according to the control method of pot galvanize unit edge dam claimed in claim 6, it is characterized in that the high speed speed setting value of described control servomotor is 300RPM to the maximum.

8. according to the control method of pot galvanize unit edge dam claimed in claim 1, while it is characterized in that described edge dam is carried out to off-position control, the off-position set-point of servomotor is calculated according to following relationship:

For back side:

$\mathrm{POS}\_\mathrm{REF}\_\mathrm{CLOSE}\_\mathrm{DR}=\mathrm{Width}\_\mathrm{DR}+\frac{\mathrm{Width}\_\mathrm{trail}-\mathrm{Width}\_\mathrm{lead}}{2}+\mathrm{OFFSET}\_\mathrm{CLOSE}$

In formula: POS_REF_CLOSE_DR: be back side servomotor position set-point;

Width_DR: be back side strip width value;

Width_trail: the rear row strip width value issued for upper computer;

Width_lead: the value of strip width in advance issued for upper computer;

OFFSET_CLOSE: be the given deviate of off-position;

For fore side:

$\mathrm{POS}\_\mathrm{REF}\_\mathrm{CLOSE}\_\mathrm{OP}=\mathrm{Width}\_\mathrm{OP}+\frac{\mathrm{Width}\_\mathrm{trail}-\mathrm{Width}\_\mathrm{lead}}{2}+\mathrm{OFFSET}\_\mathrm{CLOSE}$

In formula: POS_REF_CLOSE_OP: be fore side servomotor position set-point;

Width_OP: be back side strip width value;

Width_trail: the width value of the rear row band steel issued for upper computer;

Width_lead: for upper computer issue in advance with the width value of steel;

OFFSET_CLOSE: be the given deviate of off-position;

After air knife PLC receives the second band steel position signal of machine set PLC band steel weld seam at air knife, control the driven by servomotor edge dam and move laterally, make edge dam automatically be closed to the off-position that calculates set-point by above-mentioned expression formula.

9. according to the control method of the described pot galvanize unit of claim 1 or 8 edge dam, it is characterized in that after described air knife PLC receives the second band steel position signal of machine set PLC band steel weld seam at air knife, control the driven by servomotor edge dam and move laterally, make the automatic low speed of edge dam be closed to off-position.

10. according to the control method of pot galvanize unit edge dam claimed in claim 9, it is characterized in that the minimum 100RPM of being of low rotation speed set(ting)value of described control servomotor.

11., according to the control method of pot galvanize unit edge dam claimed in claim 1, it is characterized in that the band steel side-play amount that strip edge edge detector detects is carried out alignment processing by following relation when carrying out described automatic correction edge dam position:

For back side:

Y_EMG_DR=(PIW1086-OFFSET_DR)/100

In formula: Y_EMG_DR: for back side detects band steel side-play amount;

PIW1086: be strip edge edge detector analog input digital quantity;

OFFSET_DR: be strip edge edge detector zero offset set(ting)value after back side edge dam contact zones steel;

For fore side:

Y_EMG_OP=（PIW1084-OFFSET_OP）/100

In formula: Y_EMG_OP: for fore side detects band steel side-play amount;

PIW1084: be strip edge edge detector analog input digital quantity;

OFFSET_OP: be strip edge edge detector zero offset set(ting)value after fore side edge dam contact zones steel.

12. according to the control method of pot galvanize unit edge dam claimed in claim 1, it is characterized in that when carrying out described automatic correction edge dam position, the speed of described servomotor operation set-point is calculated according to following relationship:

In formula: SPEED_SM_DR: be back side servomotor speed preset value;

SPEED_SM_OP: be fore side servomotor speed preset value;

SET_VAL: strip edge edge and edge dam gap set(ting)value;

Y_EMG_DR: for back side detects band steel side-play amount;

K _p: be the proportional gain value of setter;

K _d: be the differential gain value of setter;

K: be the control conversion factor of servomotor;

LMN_OFF: be servomotor deviation from the index value value;

Normally in service at unit, detect and obtain being with the steel side-play amount by strip edge edge detector, the servomotor speed preset value calculated according to above-mentioned expression formula, control servomotor and automatically adjust the position of edge dam, thereby guarantee that gap between strip edge edge and edge dam is within the processing requirement scope of setting.

13., according to the control method of pot galvanize unit edge dam claimed in claim 5, it is characterized in that described weld seam crosses the preferable range of air knife safety clearance value S_gap_weld and be: 150-250mm.

14., according to the control method of pot galvanize unit edge dam claimed in claim 8, it is characterized in that the preferable range of the deviate OFFSET_CLOSE that described off-position is given is: 5-15mm.

15., according to the control method of the described pot galvanize unit of claim 12 edge dam, it is characterized in that the proportional gain value K of described setter _ppreferable range be: between 1-1.5; The differential gain value K of described setter _dpreferable range be: between 0.001-0.002.

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