KR20140032480A - Pinch roll device - Google Patents

Abstract

Pinch rolling device (1) for rolled metallurgy products,
A first pinch rolling mill and a second pinch rolling mill 2, 3, with a passage gap 5 being defined therebetween, the first and second rolling mills 2, 3 having a first and a second axis of rotation Y1. , A first pinch rolling mill 2 and a second pinch rolling mill 3, respectively rotatable with respect to Y2, to pull the metallurgical product 10 through the gap 5,
A hydraulic actuator (21, 41) comprising hydraulic actuators (21, 42, 43) connected to said first and rolling mill (2) and / or second rolling mills (2, 3), said first and second being Hydraulic actuators (21, 41), which approach or space the mills (2, 3) relative to one another to reduce or increase the width of the passage gap (5), respectively;
A pressure sensor 25 in the hydraulic circuit 20,
A position sensor 24 in the actuator 21,
In the hydraulic circuit 20, 41, which is connected to the actuators 21, 42, 43 to slidingly move the piston 22 connected to the first mill 2 and / or the second mill 3. And a reversible pump 9.

Description

Pinch roll device

The present invention relates to a pinch rolling apparatus for rolled metallurgy products.

In the line processing arts for semi-finished metallurgical products, for example wire rods, pinch rolling apparatus comprising a system for monitoring both the spacing between rolling mills and the pressure exerted by the rolling mill on rolling. It is known to use.

Among the devices of the type mentioned above, for example, it is known from the patent US 6,920,772, where the rolling mill is connected to two cranks, each connected to a single electrically proportional motor. The controlled rotation of the proportional motor controls the mutual access of the two rolling mills in one direction and the separation in the opposite direction by two cranks. When the machined product is between rolling mills, a proportional motor with two cranks allows to adjust the thrust of each rolling mill to the other rolling mill, thus controlling the pressure exerted on the rolling mill by the rolling mill. .

The device disclosed in US Pat. No. 6,920,772 addresses a series of disadvantages due to the inevitable repulsion and structural complexity on the transmission chain between the servo motor and the rolling mill, determined by the type and number of mechanical members selected to connect the servo motor to the rolling mill. Have Thus, such a device does not allow to effectively control the spacing between the rolling mills during both the waiting phase, ie during the working stage and when no product is rolled between the rolling mills. During the working phase, in the apparatus disclosed in US Pat. No. 6,920,772, the spacing between rolling mills is controlled only by a dynamic chain comprising electromechanical members, the dynamic stress caused by the contact between the product and the rolling mills being controlled by the juddering) and consequently determine the intermittent loss of contact between the rolling mill and the products being rolled. The inability to guarantee a constant pinching operation implies device instability even upstream of the rolling line to be delivered. Moreover, the judder of the pinch rolling apparatus causes surface defects of the products to be rolled, which degrades the quality and increases the product rejection rate.

Other pinch rolling devices are also disclosed in US 2003/034376 and EP 019298, which allow the spacing between rolling mills to be controlled by a hydraulic actuator comprising one or more hydraulic cylinders controlled by a servovalve. Here, the use of hydraulic circuits including servo valves determines a number of disadvantages, the main disadvantages of which are:

Low operating speed of the servovalve (order of 40-50 Hz), consequently low operability of the hydraulic circuit;

Open circuit operation, consequently the need to provide external hydraulic attachments;

High operating and maintenance costs due to the typical short life of servovalve.

In addition, the device disclosed in US 2003/034376 and EP 0192982 can be improved with regard to rolling positioning accuracy.

The object of the present invention allows to solve the above mentioned disadvantages of the prior art, thus allowing to precisely control both the mutual spacing between the pinch rolling mills and the pressure exerted on the product by the rolling mill during rolling, thereby rolling the rolling mill and rolling It is to provide a novel pinch rolling apparatus for rolled metallurgy products, which ensures a continuous and even contact between the resulting products.

Another object is to make available a new pinch rolling device for rolled metallurgical products which is fully automated and does not require any manual intervention of the operator, for example for compensation of rolling mill wear.

Yet another object is to allow high passing speeds of products of up to 150 m / s between rolling mills.

Another object of the present invention is to make available a pinch rolling device controlled by a hydraulic circuit having a scale much smaller than the prior art in terms of the length of the hydraulic line and the working fluid.

Another object is to make available the method of operation for the pinch rolling apparatus described above.

According to the invention, the above technical problems are solved by a pinch rolling apparatus having the features described in claim 1 of the independent claim and a method having the features described in claim 8 of the independent claim.

In particular, in a first aspect the present invention relates to a pinch rolling apparatus for a rolled metallurgical product, the pinch rolling apparatus comprising:

A first pinch rolling mill and a second pinch rolling mill, wherein a passage gap for the rolled metallurgical product is defined therebetween, wherein the first and second rolling mills are rotatable about the first and second rotational axes, respectively, through the gaps; Frictional drawing of the metallurgical product, the first pinch rolling mill and the second pinch rolling mill,

Hydraulic circuits operating in said first and second rolling mills, said first and second rolling mills approaching or spaced apart from one another to reduce or increase the width of said passage gap, respectively, said hydraulic circuit being said A hydraulic circuit connected to a first rolling mill and / or said second rolling mill and including a hydraulic actuator for approaching or spaced apart said first and second rolling mills from each other,

The pinch rolling device is:

A pressure sensor in the hydraulic circuit, for determining the force transmitted by the actuator to the first rolling mill,

A position sensor in the actuator, for determining movement of the first rolling mill,

A reversible pump in the hydraulic circuit, the pump further connected to the actuator and slidingly moving the piston of the actuator, the piston further comprising a reversible pump connected to the first rolling mill and / or the second rolling mill. .

In this invention, due to the presence of pressure and position sensors, both the spacing between the rolling mills and the thrust on the rolling mills during rolling are controlled in an optimized manner, ensuring continuous and even contact between the rolling mill and the product being rolled. , Pinch rolling apparatus can be obtained.

In a second aspect, the present invention relates to a method of operating a pinch rolling apparatus for a rolled metallurgical product, the apparatus comprising:

A first pinch rolling mill and a second pinch rolling mill, wherein a passage gap for the rolled metallurgical product is defined therebetween, wherein the first and second rolling mills are rotatable about the first and second rotational axes, respectively, through the gaps; Frictional drawing of the metallurgical product, the first pinch rolling mill and the second pinch rolling mill,

A hydraulic actuator connected to the first rolling mill to approach or separate from the second rolling mill to reduce or increase the width of the passage gap, respectively,

A reversible pump in the hydraulic circuit, the pump being connected to the actuator and slidingly moving the piston of the actuator, the piston comprising a reversible pump connected to the first rolling mill and / or the second rolling mill,

The method comprises:

Identifying the presence or absence of the metallurgical product in the passage gap,

A step performed if the metallurgical product is identified as absent in the passage gap in the checking step, identifying the position of the first rolling mill,

A step performed when it is identified that the metallurgical product is present in the passage gap, the step of checking the pressure of the hydraulic actuator, the pressure checking step comprising a sub-step of regenerating a position reference value Steps.

Similar to the foregoing in the first aspect, the present invention comprises a positioning step that allows setting the gap between rolling mills prior to the passage of the product and a pressure checking step that allows adjusting the rolling thrust during rolling. It allows to obtain a method of operating the pinch rolling apparatus for metallurgical products in an optimized control method. The two steps are performed alternatively with respect to each other and have the advantage of increasing the passing speed of the product between the rolling mills, allowing to optimize the control cycles which can be carried out quickly.

Another advantage of the present invention is obtained by a pinch rolling apparatus according to the dependent claims, which is detailed below.

Including a first mill and a second mill interconnected to each other by mechanical and / or hydraulic connections allow access of the two mills in a symmetrical manner with respect to the cross-axis or spaced from one another. Finely and effectively control the size of the gap. In particular, the hydraulic actuator acting directly on only one of the two mills and the other controlled by the gear transmission between the two mills allows synchronization of movement due to the direct coupling of the first and second mills, which Mechanical linkage transmissions are a simpler method than known solutions, for example the solution of US 6,920,772, which connects the actuating member to two rolling mills.

Alternatively, the use of two hydraulic actuators, each acting on two rolling mills and connected to each other by means of a compensation circuit, allows to obtain the same accuracy and the same structural simplicity.

The use of a hydraulic control circuit allows to obtain the stability of the system by dampening the stress between the rolling mills and the rolled product operated by the hydraulic fluid. Moreover, the closed and pressurized hydraulic circuit allows to have a very small size for a typical hydraulic circuit comprising a hydraulic unit.

In the hydraulic circuit, the use of a reversible pump controlled by an electric motor and then controlled by a control unit connected to a position and pressure sensor, the hydraulic power used to control the hydraulic components to approach or space the rolling mills from one another. It permits to achieve an electrical type control system and allows electrical components to effectively acquire position and pressure feedback control. This is desirable to allow integration with the features of the hydraulic system, in particular with the possibility of applying high pressure to the features of the electrical system, in particular with the control speed and reliability.

The use of a reversible pump controlled by an electric motor allows to omit servo valves commonly used in hydraulic circuits, further reducing the amount of fluid required for the hydraulic circuit and its entire length.

Other features and objects of the present invention will become more apparent in the following detailed description of the preferred embodiments, which is merely non-exclusive and referred to as non-limiting examples, and with reference to the accompanying drawings, in which: Is the same as
1 is a schematic view of a pinch rolling apparatus for a rolled metallurgical product according to the present invention,
2 is a front view of some components of the apparatus of FIG. 1,
3 is a side view of the component of FIG. 2,
4 is a schematic representation of another configuration of the apparatus of FIG. 1,
5 is a flow chart of a method for operating a pinch rolling apparatus for a rolled metallurgical product according to the invention.

1 to 3, the entirety of the pinch rolling apparatus for a rolled metallurgical product of round cross section is indicated by reference numeral 1. In general, the pinch rolling apparatus provided in accordance with the present invention may be suitably configured to hold any rolled metallurgical product, for example a rolled product of flat cross section.

The apparatus 1 comprises a first pinch rolling mill 2 and a second pinch rolling mill 3 which is identical to the first rolling mill 3, between which the substantially circular passage gap 5 for the wire rod 10 is located. ) Is specified. The gap 5 defines an intersecting axis X coaxial to the gap 5, which is aligned with the wire rod 10 during operation through the passage gap 5.

The first and second rolling mills 2 and 3 can rotate about the first and second rotational axes Y1 and Y2, respectively, so that the wire rod 10 is pulled through the passage gap 5 by friction. Lose. The axes of rotation Y1, Y2 are parallel to each other and evenly spaced from the intersecting axis X and aligned on opposite sides to each other. The shape and size of the gap 5 corresponds to that of the wire rod 10, with the gap 5 being two annular grooves 5a, 5b respectively provided on the circular circumferential surfaces of the pinch rolling mills 2, 3. The range is determined by The first and second rolling mills 2, 3 are respectively restrained on the first lever arm 7 and the second lever arm 8 so as to rotate about the rotation shafts Y1, Y2. The rotation of the pinch rolling mills 2, 3 about the rotation shafts Y1, Y2, which are integrated with the first and second arms 7, 8, respectively, is a pair of drive gear wheels coaxial to the shafts Y1, Y2. Acquired by a conventional and known actuator comprising a drive motor (not shown) connected to the rolling mills by a transmission comprising a pair of drive gear wheels 2b, 3b interlocked for counter-rotation with 2a, 3a). do. The drive gear wheels 2a and 3a mesh with the drive gear wheels 2b and 3b, respectively, and receive movement therefrom. The rotational motion is transmitted by the drive motor to the drive gear wheels 3b due to the motion output shaft 3c. Movement from the drive gear wheels 3b is transmitted to the other drive gear wheels 2b and the drive gear wheels 3a. Movement from the drive gear wheels 2b is transmitted to the other drive gear wheels 2a. Due to the coupling described, the drive gear wheels 2a and 3a and hence the respective mills 2 and 3 rotate counter-rotating.

The first and second arms 7, 8 are identical to each other, each of which is parallel to one another and is equally spaced from the intersecting axis X and aligned on the opposite side with respect to the third and fourth rotational axes ( A pair of respective hinges defining Z2) is rotatably supported relative to a fixed reference system integrated with the cross axis X.

The first and second arms 7, 8 can rotate about Z1 and Z2, respectively, so that the first and second rolling mills 2, 3 respectively reduce or increase the width of the passage gap 5. Approach or space each other away. The third and fourth axes of rotation Z1, Z2 are apart from and parallel to the first and second axes of rotation Y1, Y2 along the respective arms 7, 8, respectively. In fact, the four axes Y1, Y2, Z1 and Z2 form a parallel axis system at all operating conditions of the device 1.

In order to control the rotation of the lever arms 7, 8 and thus to access or space the first and second rolling mills 2, 3 from each other, the device 1 is in its interior, for example oil-like. It comprises a hydraulic circuit 20 through which hydraulic fluid circulates and a mechanical gear transmission 11 to which the first and second rolling mills 2, 3 are interconnected.

The hydraulic circuit 20 is closed and pressurized so that no hydraulic control unit is required and includes a hydraulic actuator 21 connected to the first rolling mill 2 to approach or be spaced apart from the second rolling mill 3. do. The actuator 21 comprises a stem 31 which is hinged to the first lever arm 7 near its second rolling mill 2 at its free end 31a. The transmission of the stem 31 determines the corresponding rotation of the lever arm 7 about the third axis of rotation Z1. The same rotation is transmitted to the second arm 8 by the transmission 11.

The transmission 11, which allows the hydraulic actuator 21 to be connected to the second rolling mill 3 by the first rolling mill 2, has a lever arm 7, 8 and the first lever arm 7 and a second lever arm. 8 between gears 12. The gear 12 comprises a first gear sector 12a and a second gear sector 12b which are integral with and engaged with the first and second arms 7, 8, respectively, and thus correspond to the actuator 21. Each rotation transmitted to the first arm 7 is thereby transmitted to the second arm 8.

The first and second gear sectors 12a, b are provided at the ends of the third arm 32 and the fourth arm 33, respectively, and are integrated with the first and second arms 7, 8 and with each other. And is orthogonal to the intersecting axis (X). The arms 32, 33 are aligned opposite to the crossing axis X such that the first and second gear sectors 12a, b engage with each other at the same crossing axis X. The transmission ratio of the gears 12 is united so that each rotation of the first arm 7 corresponds to the same but opposite rotation of the second arm 8. The gear 12 allows to obtain synchronized and organized movement of the first and second arms 7, 8 and the rolling mills 2, 3 restrained thereto. Thus, the assembly consisting of the first arm 7 and the first rolling mill 2 restrained therewith is identical to the second arm 8 and the second rolling mill 3 restrained thereon with respect to the axis X in all operating conditions. And are synchronized.

According to another structural variant (not shown) of the present invention, the first and second rolling mills 2, 3 can be interconnected with one another by means of other types of mechanical connections, for example comprising a plurality of linkages and without gears. .

The hydraulic actuator 21 can be of a double-effect type, comprising a first chamber 21a and a second chamber 21b, which are connected to the stem 31 and the second stem 31b. The piston 22 slides in between, which is also located on the opposite side of the stem 31 and has the same diameter. In order to control the movement of the piston 22, the hydraulic circuit 20 is connected to the first and second chambers 21a of the actuator by each of the first branch 20a and the second branch 20b of the hydraulic circuit 20. and a reversible pump 9 connected to b). Rotation in one direction or the other of the reversible pump 9 permits the direct transfer of oil to either one or the other of the chambers 21a, b of the actuator 21, respectively, thus providing a piston 22 and The movement of the stem 31 in one direction or the other is determined.

The pump 9 which controls the movement of the piston 22 is operated by the electric motor 9a; Accordingly, the position of the piston 22 inside the cylinder depends on the angular position of the motor 9a of the pump 9, and the moving speed of the cylinder depends on the angular speed of the pump 9.

As the hydraulic circuit 20 is closed and pressurized, ie without the hydraulic control unit, the same amount of fluid always circulates inside it. The motor 9a of the pump 9 determines each fluid movement in the hydraulic circuit 20: thus, if the motor 9a does not operate the pump 9, at each point of the hydraulic circuit 20 There is virtually no fluid flow and the piston 22 does not move.

A connecting branch is provided between the first branch 20a and the second branch 20b of the hydraulic circuit 20, and is provided with a calibrated maximum pressure valve 29, which is applied to the first rolling mill 2 and the stem ( 31) to protect the hydraulic circuit from pressure overload caused by excessive and pulsating loads transmitted to the actuator 2. The first and second branches 20a, b are connected to a top-up source 27 upstream of the reversible pump 9, which further-fills any fluid leaks from the hydraulic circuit 20. Allow. The first check valve 28a and the second check valve 28b are directed in a direction that prevents flow from the pump 9 to the add-fill source 27 and allows flow in the opposite direction, It is provided between the refill source 27 and the reversible pump 9 on each of the second branches 20a, b.

The amount of fluid required for the operation of the hydraulic circuit 20 is given by the sum of the circulating fluid and the fluid present in the add-fill source 27, preferably in the range of 0.5 to 2 liters, more preferably 0.7 to 1.4 liters. Do. As the hydraulic circuit 20 is closed, it is also possible to gauge its size: the total length of the fluid line through which the fluid circulates is preferably 0.5 to 1.5 meters, more preferably 0.7 to 1 meters.

The reversible pump 9 and thus the actuator 21 are operated in a controlled manner. A feedback control circuit 30 is included and includes an electric motor 9a connected to the pump 9 by a connector 9b. The control circuit 30 includes a pressure sensor 25 located between the actuator 21 and the maximum pressure valve 29 in the first branch 20a of the hydraulic circuit 20, and a position sensor in the actuator 21. It further includes (24). The pressure sensor 25 allows to measure the pressure in the circuit, in particular in the chamber 21a, thus applying the force F1 transmitted by the actuator 21 to the first mill 2 through the stem 31. Decide Force F1 is transmitted from the first rolling mill to the wire rod 10. The same counter force F2 transmitted from the second mill 3 to the wire rod 10 is such that the transmission of the device F1 is achieved by means of the transmission 11 to obtain the device balance obtained through the connection between the arms 7, 8. Corresponds to). The rolling force and pressure can be controlled by controlling the pressure in the hydraulic circuit 20. The position sensor 24 is allowed to measure the movement of the piston 22 and thus to determine the movement of the first rolling mill 2. The position of the first rolling mill 2 can be controlled by means of the transmission 11 by controlling the position of the piston 22, and the position of the second rolling mill 3 can also be controlled, so that the passage gap 5 can be controlled. The width of is adjusted. The control circuit 30 further includes a control unit 26, whereby the electric motor 9a is controlled. The control unit 26 is connected to the position sensor 24 and the pressure sensor 25 to obtain feedback control. The control unit 26 receives the pressure and position data measured by the sensors 25, 24 and processes them to determine the width value of the force F1 and the passage gap 5. The control unit 26 then compares these values to their respective reference values, thus controlling the electric motor 9a and modifying or maintaining the width of the force F1 and the passage gap 5 according to the method of operation 100. The important steps are described below.

With reference to FIG. 4, the entire pinch rolling apparatus for the wire rod is referred to by reference numeral 40, the structural modification of which is different from the apparatus 1 and includes a different hydraulic circuit 41, which will be described in detail below. . The other components of the device 40 are not described as being identical to each of the components described above in the device 1. The hydraulic circuit 41 is different from the hydraulic circuit 20 of the apparatus 1, which is connected to the first mill 2 and the second mill 3 respectively instead of the dual-utility hydraulic actuator 21. A pair of single-effect hydraulic actuators 42, 43 are included. Each hydraulic actuator 42, 43 includes a piston 22 that slides between each upper first chamber 42a, 43a and each lower chamber 42b, 43b. The upper chambers 42a, 43a of the hydraulic actuators 42, 43 are connected to the first and second branches 20a, b of the hydraulic circuit 41, respectively. The lower chambers 42b and 43b of the hydraulic actuators 42 and 43 are connected to each other by hydraulic connections constituting the compensating circuit 44, whereby the first and second rolling mills 2 and 3 are connected to each other, When the first rolling mill 2 moves from or towards the second rolling mill 3, the second rolling mill moves from or towards the first rolling mill 2. In the modification of FIG. 4, as in the modification of FIG. 3, the first rolling mill 2 and the second rolling mill 3 also space or approach symmetrically with respect to the cross axis X. FIG. When the reversible pump 9 sends oil directly to the upper chamber 42a of the actuator 42 by the first branch 20a, each piston 22 pushes oil through the compensating circuit 44 and At the same time, it moves to the lower chamber 43b of the actuator 43 toward the lower chamber 42b, and each of the pistons 22 moves toward the respective upper chamber 43a. Alternatively, when the reversible pump 9 sends oil directly to the upper chamber 43a of the actuator 43 by the second branch 20b, each piston 22 is supplied via the compensation circuit 44 to the oil. And simultaneously move toward the lower chamber 42b of the actuator 42 toward the lower chamber 43b so that each of the pistons 22 moves toward the respective upper chamber 42a.

According to another structural modification of the present invention (not shown), the pinch rolling apparatus according to the present invention includes a hydraulic circuit similar to the circuit 41 without the transmission 11.

Referring to the flow chart of FIG. 5, the method 100 of operation of the apparatus 1, which can be performed in the control unit 26, comprises an initial stage 50, in which the rolling mill 2, 3 is operated. Check whether it is fixed or rotating about each of the rotation shafts Y1 and Y2. If the mills 2 and 3 are fixed, the method 100 terminates and proceeds to the next stop step 51. If the mills 2, 3 are rotating by a pair of gears 2a, 3a, the method 100 continues to the next step 52, where the control motor 9a of the pump 9 is Check if it is stopped or running. If the motor 9a is stopped, the method 100 terminates and proceeds to the stop step 51. If the motor 9a is running, the method 100 continues to the next step 53 of setting a reference value, where the type and feature of the machined product, for example the wire rod 10, is identified, The first reference value 61 of the position of the piston 22 and the second reference value 71 of the pressure of the circuit 20 are set according to the function of the identified product.

The method 100 continues to the next step 54 to identify the presence or absence of the machined metallurgical product, for example the wire rod 10, in the passage gap 5 between the rolling mills 2, 3. In order to carry out the confirmation step 54, the control unit 26 receives external data identifying the presence or absence of the metallurgical product to be machined, which is arranged upstream of the passage gap 5 for example and Obtained from one or more sensors (not shown), such as a photocell, connected to 26).

If the absence of the metallurgical product machined in the passage gap 5 is identified in the identification step 54, the method 100 identifies the position of the piston 22 and thus the location of the first rolling mill 2. Continue to 110. Alternatively, if the presence of the metallurgical product machined in the passage gap 5 is identified in the confirmation step 54, the method 100 continues to the pressure confirmation step 120 so that the pressure in the actuator 21 is confirmed. do.

At the end of either the positioning step 110 or the pressure checking step 120, the method 100 includes a step 80 of confirming the end of the machining, where for example a switch or The signal supplied to the control unit 26 by any other type of component that can be controlled by the operator is used to determine whether the machining process is continuing or has ended. If the rolling process is finished, the method 100 continues to the final step 81 where the first and second rolling mills 2, 3 take a maximum distance from each other. Alternatively, if the rolling process has not ended, the method 100 continues to repeat step 53 of setting a reference value.

The positioning step 110 is based on the current position of the piston 22, which may be related to the position of the first rolling mill 2 due to the connection by the stem 31 by means of the measurement supplied by the position sensor 24. A first sub-step 60 of determining the measurement. A second position comparison sub-step 62 follows the first sub-step, comparing the measured value of the position identified by the first sub-step 60 to the reference position value 61. The comparison is performed by subtracting the measured value from the reference value. The positioning step 110 continues to the third checking sub-step 64, so that the method checks whether the subtraction performed during the second sub-step 62 has a result of zero or a result different from zero. . If the result is zero, the positioning step 110 ends and the method 100 continues to the machining-finish checking step 80, and if the result is different from zero, the positioning step 110 is the fourth sub. Continuing with step 63 a movement is made by the motor 9a and the reversible pump 9 on the piston 22 and reaches a position corresponding to the reference value 61. The movement made in the piston 22 is proportional to the difference between the measured position value and the reference position value 61. At the end of the fourth sub-step 63, the positioning step 110 ends and the method 100 continues to the machining-finish checking step 80.

The pressure checking step 120 comprises a fifth quick access sub-step 59, wherein the mills 2 and 3 have access to the rolled product machined upstream of the reversible pump 9 and the hydraulic circuit ( Subsequent to the sixth sub-step 70 of determining the measurement of the pressure in the first branch 20a of 20, which is due to the proximity of the pressure sensor 25 of the actuator 21 to the first of the actuator 21. By measurement provided by a pressure sensor 25 which may be related to the pressure of the chamber 21a. The seventh pressure comparison sub-step 72 follows the sixth sub-step, and compares the measured pressure value identified in the sixth sub-step 70 with the reference position value 71. The comparison is performed by subtracting the measured value from the reference value. The pressure checking step 120 continues to the eighth checking sub-step 75, where the method checks whether the subtraction result performed in the seventh sub-step 72 is zero or different from zero. If the result is zero, the pressure checking step 120 proceeds to the ninth sub-step 74 of regenerating the reference position, where the first reference value 61 of the position of the piston 22 is returned to its current value. Is updated. At the end of the ninth sub-step 74, the pressure checking step 120 is performed and the method 100 continues to the machining-finish checking step 80. If the subtraction result calculated in the eighth verification sub-step 75 is not zero and is different from zero, the pressure verification step 120 proceeds to the tenth sub-step 73, where the motor on the piston 22 Movement is performed by 9a and the reversible pump 9 to reach a pressure corresponding to the reference value 71. The movement made by the piston 22 is proportional to the difference between the measured value and the reference pressure value 71. At the end of the tenth sub-step 73, the pressure check step 120 ends and the method 100 continues to the machining-end check step 80.

In the aforementioned method, the force checking step 110 and the positioning step 120 are performed alternatively to each other, which can be carried out very quickly, typically at a frequency of 3000 Hz. This creates the possibility that the machined product can reach the feed rate in the order of 150 m / s along the cross axis (X).

In addition, the method 100 described above may also be used in other pinch rolling apparatuses other than apparatus 1, such apparatus including:

A first pinch rolling mill and a second pinch rolling mill, between which a passage gap for the rolled metallurgical product is defined, rotatable along the first axis of rotation Y1 and the second axis of rotation Y2, respectively, through the passage gap; Frictional drawing of the metallurgical product, the first pinch rolling mill and the second pinch rolling mill,

A hydraulic actuator connected to the rolling mills to reduce or increase the width of the passage gap, respectively, by approaching or spacing them in a controlled manner,

A reversible pump connected to the hydraulic actuator for slidingly moving the piston connected to the first and / or second pinch rolling mill.

The aforementioned technical solutions allow for a sufficient solution of the problems and problems with reference to the aforementioned prior art, and thus have a number of additional advantages, including:

Use a high efficiency, closed hydraulic circuit containing only the minimum amount of fluid, ie the amount of fluid required to move the piston of the hydraulic actuator. This makes it possible to obtain hydraulic circuits characterized by high reactivity. It also encourages the use of hydraulic pumps controlled by electric motors (up to 200-300 Hz) that allow reaching operating speeds much higher than those that can be driven by servo valves (up to 200-300 Hz);

Obtaining a device which is not affected by the inevitable wear of the pinch rolling mill, which can be compensated by the rotation of the lever arm supporting the rolling mill;

To obtain a self-damping system, so that the damping function is performed by the fluid in the hydraulic control circuit and therefore no insertion of additional damping members is required;

Use of a hydraulic system without servo valves, thus allowing a very large reduction in operating and maintenance costs.

Claims (11)

Pinch rolling apparatus 1, 40 for a rolled metallurgy product, the pinch rolling apparatus of which
A first pinch rolling mill 2 and a second pinch rolling mill 3, in which a passage gap 5 for the rolled metallurgical product 10 is defined, wherein the first and second rolling mills 2, 3 Is a first pinch rolling mill (2) and a second pinch rolling mill (2), which are rotatable about the first and second rotary shafts (Y1, Y2) to pull the metallurgical product (10) by friction through the gap (5). 3),
Hydraulic circuits 20, 41 operating in said first and second rolling mills 2, 3, said passages being approached or spaced apart from each other with respect to said first and second rolling mills 2, 3, respectively; To reduce or increase the width of the gap 5, the hydraulic circuit 20 is connected to the first rolling mill 2 and / or the second rolling mill 3, the first and second rolling mill 2, A hydraulic circuit 20, 41, comprising at least one hydraulic actuator 21, 42, 43 to approach or space 3) relative to one another;
The pinch rolling device,
A pressure sensor 25 in the hydraulic circuit 20, 41 for determining the force transmitted by the actuators 21, 42 to the first mill 2 and / or the second mill 3. ,
A position sensor 24 in the actuators 21, 42 for determining the movement of the first mill 2 and / or the second mill 3,
A reversible pump 9 in the hydraulic circuit 20, 41, which is connected to the actuators 21, 42, 43 to connect the pistons 22 of the actuators 21, 42, 43. Sliding movement, the piston is connected to the first mill 2 and / or the second mill 3, a reversible pump 9
Lt; RTI ID = 0.0 > 1, < / RTI &
Pinch rolling device (1, 40).
The method of claim 1,
The first and second rolling mills 2, 3 are interconnected with respect to each other by mechanical and / or hydraulic connections 11, 44,
Pinch rolling device 1.
3. The method of claim 2,
The hydraulic circuits 20, 41 comprise hydraulic actuators 21, 42 connected to the first rolling mill 2, the connecting parts 11, 44 being connected between the first and second rolling mills 2, 3. Connecting the hydraulic actuators 21, 42 to the second rolling mill 3 by means of the first rolling mill 2, including a gear transmission 11 of
Pinch rolling device 1.
The method according to claim 2 or 3,
The hydraulic circuit 41 includes a pair of hydraulic actuators 42 and 43 connected to the first and second rolling mills 2 and 3, respectively, to connect the second rolling mill 3 to the first rolling mill ( While moving from 2) and towards the first rolling mill, the first rolling mill 2 is moved out of the second rolling mill 3 and moved towards the second rolling mill, and the connecting portions 11 and 44 are Comprising a compensating circuit 44 between the first and second rolling mills 2, 3,
Pinch rolling device 1.
The method according to claim 3 or 4,
The transmission 11 comprises first and second lever arms 7, 8, the first and second rolling mills 2, 3 being restrained against them to rotate about the rotational axes Y1, Y2, respectively. The first and second arms 7, 8 are rotatable about a third and fourth rotational axis Z1, Z2 to bring the first and second rolling mills 2, 3 closer to each other. Or spaced apart, the gear 12 comprises at least a first gear sector 12a and a second gear sector 12b, each of which is integral with the first and second arms 7, 8. The first and second gear sectors 12a, 12b are engaged with each other to transfer rotation between the first and second levers 7, 8,
Pinch rolling device 1.
The method of claim 5, wherein
The first, second, third, and fourth rotational axes Y1, Y2, Z1, Z2 are parallel to each other,
Pinch rolling device 1.
The method of claim 1,
The pump 9 is controlled by an electric motor a with controlled means of a control unit 26 connected to the position sensor 24 and the pressure sensor 25,
Pinch rolling device 1.
A method 100 for operating a pinch rolling apparatus 1 for a rolled metallurgical product, the apparatus comprising:
A first pinch rolling mill 2 and a second pinch rolling mill 3, in which a passage gap 5 for the rolled metallurgical product 10 is defined, wherein the first and second rolling mills 2, 3 The first pinch rolling mill (2) and the second pinch rolling mill (3), which are rotatable about the first and second rotary shafts (Y1, Y2) to pull the metallurgical product (10) by friction through the gap, respectively.
At least one connected to the first and second rolling mills 2, 3 to close or space the mills 2, 3, respectively, to reduce or increase the width of the passage gap 5, respectively. Hydraulic actuators (21, 42, 43),
A reversible pump 9 in the hydraulic circuit 20, 41, which is connected to the actuators 21, 42, 43 to connect the pistons 22 of the actuators 21, 42, 43. Slidingly moving, the piston comprises a reversible pump 9, which is connected to the first rolling mill 2 and / or the second rolling mill 3,
The method 100,
Identifying 54 the presence or absence of the metallurgical product 10 in the passage gap 5,
A step performed when the identification step 54 identifies the absence of the metallurgical product 10 in the passage gap 5, the step 110 of identifying the position of the first rolling mill 2,
A step performed when it is identified that the metallurgical product 10 is present in the passage gap 5, the step of checking the pressure of the hydraulic actuator 21, the pressure checking step 120 Includes a pressure checking step 120, comprising a sub-step 74 of regenerating a position reference value,
How it works (100).
The method of claim 8,
The step 110 of identifying the position of the first mill 2 is a position comparison sub-step of comparing the measured position value, which may be related to the position of the first mill 2, to a reference position value ( Which includes 62),
How it works (100).
10. The method according to claim 8 or 9,
The step 120 of identifying the pressure of the hydraulic actuator 21 includes a pressure comparison sub-step 72 that compares the measured pressure value, which may be related to the hydraulic actuator 21, to a reference pressure value. doing,
How it works (100).
The method of claim 8,
The sub-step 74 of regenerating the position reference value is performed when the measured pressure value is identified as being equal to the pressure reference value in the pressure comparison sub-step 72,
How it works (100).

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