阅读说明：本技术 一种二十辊轧机的张力标定装置及张力标定方法 (Tension calibration device and tension calibration method of twenty-high rolling mill ) 是由 张春杰 宋征 于 2020-03-04 设计创作，主要内容包括：本发明公开了一种二十辊轧机的张力标定装置,包括配重架、压轴和配重块；配重架一端与二十辊轧机入口处的连接轴转动连接；连接轴位于第一减速机输出轴与入口支撑辊之间；配重架上按预设间隔依次设有N个连接机构,以连接配重块；压轴的一端连接至配重架,另一端通过配重架的转动压在二十辊轧机上的带钢上表面；通过上述装置,能够在带钢建张之后通过压轴传递给带钢一个可量化的压应力,然后根据带钢在此压应力作用下形成的角度θ,综合确定当前带钢的实际张力T<Sub>act</Sub>,并建立起二十辊轧机设定张力T<Sub>set</Sub>和实际张力T<Sub>act</Sub>之间的映射关系；从而能够提高了二十辊轧机的张力控制精度,保证了板形质量。(The invention discloses a tension calibration device of a twenty-high rolling mill, which comprises a counterweight frame, a pressing shaft and a counterweight block; one end of the counterweight frame is rotationally connected with a connecting shaft at the inlet of the twenty-high rolling mill; the connecting shaft is positioned between the output shaft of the first speed reducer and the inlet supporting roller; n connecting mechanisms are sequentially arranged on the counterweight frame at preset intervals so as to be connected with the counterweight blocks; one end of the pressing shaft is connected to the counterweight frame, and the other end of the pressing shaft is pressed on the upper surface of the strip steel on the twenty-high rolling mill through the rotation of the counterweight frame; the device can transmit a quantifiable compressive stress to the strip steel through the pressing shaft after the strip steel is tensioned, and then comprehensively determine the actual tension T of the current strip steel according to the angle theta formed by the strip steel under the action of the compressive stress act And a set tension T of the twenty high rolling mill is established set And the actual tension T act The mapping relationship between the two; therefore, the tension control precision of the twenty-high roll mill can be improved, and the plate shape quality is ensured.)

1. A tension calibration device of a twenty-high rolling mill is characterized by comprising a counterweight frame, a pressing shaft and a counterweight block; one end of the counterweight frame is rotationally connected with the connecting shaft at the inlet of the twenty-high rolling mill; the connecting shaft is positioned between the output shaft of the first speed reducer and the inlet supporting roller; n connecting mechanisms are sequentially arranged on the counterweight frame at preset intervals to connect the counterweight blocks, wherein N is greater than or equal to 1 and is a positive integer; one end of the pressing shaft is connected to the counterweight frame, and the other end of the pressing shaft is pressed on the upper surface of the strip steel on the twenty-high rolling mill through the rotation of the counterweight frame;

the tension calibration device is used for calibrating the mass m of the counterweight frame₁Mass m of said weight member₂The connecting mechanism of the connecting counterweight block is far away from the distance L of the connecting shaft, an included angle α between the weight frame and the gravity direction, the included angle theta of the strip steel on two sides of the pressing shaft and the reaction of the strip steel on the stress direction of the pressing shaft and the included angle β between the weight frames are determined by the current actual tension T of the strip steel_actObtaining a set tension T of the twenty high rolling mill_setWith said actual tension T_actThe mapping relationship between them.

2. The tension calibration device as claimed in claim 1, further comprising a strip steel fixing frame fixedly connected with the platform of the twenty-high rolling mill, wherein one end of a strip steel on the twenty-high rolling mill is fixedly connected to the strip steel fixing frame, and the other end of the strip steel penetrates through the roll set of the twenty-high rolling mill and is wound to the output shaft of the second reducer.

3. A tension calibration method of a twenty-high rolling mill, characterized in that the tension calibration apparatus as claimed in claim 1 or 2 is used, the tension calibration method comprising:

obtaining the current set tension T of the twenty-high rolling mill_setAnd mass m of the weight holder₁；

Determining mass m of the counterweight₂And the connecting position of the counterweight block on the counterweight frame, wherein the distance between the connecting mechanism for connecting the counterweight block and the connecting shaft is L;

determining an included angle α between the weight frame and the gravity direction, an included angle theta of the strip steel on two sides of a pressure shaft, and an included angle β between the stress direction of the strip steel reacting on the pressure shaft and the weight frame;

according to said m₁，m₂L, theta, determining the current actual tension T of the strip_act；

Changing the set tension T of the twenty high rolling mill_setRepeating the steps to obtain a mapping relation between the set tension and the actual tension;

and controlling the strip steel production according to the mapping relation.

4. The tension calibration method as set forth in claim 3, wherein said m is a function of₁，m₂L, theta, determining the current actual tension T of the strip_actThe method specifically comprises the following steps:

according to said m₁，m₂L, calculating the stress F' of the strip steel reacting on the pressure shaft according to the moment balance;

determining the current actual tension T of the strip steel according to the stress F' and the stress theta and the force balance_act。

5. The method of claim 4, wherein calculating the stress F' on the strip steel reacting against the press axis based on the moment balance comprises:

the stress F ═ km₁g+Lm₂g) × sin α/sin β, wherein k is a constant greater than 0.

6. Method according to claim 4, characterized in that the current actual tension T of the strip is determined on the basis of the force balance_actThe method specifically comprises the following steps:

according toCalculating the actual tension T_act。

7. The tension calibration method as claimed in claim 3, wherein the set tension T of the twenty-high rolling mill at the current time of obtaining is obtained_setAnd mass m of the weight holder₁Before, still include:

calculating the maximum bending stress of the output shaft of the first speed reducer under the maximum set tension;

determining that the maximum bending stress is within an allowable stress of the first reducer output shaft.

8. The tension calibration method as set forth in claim 3, wherein the strip steel is a stainless steel strip having a surface roughness within 0.8 μm.

Technical Field

The application relates to the technical field of cold rolling equipment, in particular to a tension calibration device and a tension calibration method of a twenty-high rolling mill.

Background

The output capacity of cold-rolled steel strip in steel rolling plays a role in examining the state industrial level. The rapid development of industrial technology requires the high-precision, wide and thin metal strips such as silicon steel, stainless steel, alloy steel and the like which are difficult to deform to have good quality and huge yield. The rolling production of metal foil strips, particularly the production of foil strips of stainless steel, copper and the like with high yield strength is limited by the minimum rollable thickness, and a multi-roll mill with small working roll diameter is adopted, and the twenty-roll mill is the most common.

At present, twenty-high rolling mills with long service time and low assembly precision often have the problems of poor stability, large deviation between actual tension and set tension and inaccuracy. In the strip rolling of the twenty-high rolling mill, the accuracy of actual tension control is necessary basic work for improving the quality of the strip shape and forming a strip shape control technology. In order to further improve the strip shape quality of the stainless steel strip, a solution capable of accurately calibrating the actual tension of the twenty-high rolling mill and improving the tension control precision of the rolling mill is needed.

Disclosure of Invention

The invention provides a tension calibration device and a tension calibration method of a twenty-high rolling mill, which aim to solve or partially solve the technical problems that the set tension and the actual tension of the twenty-high rolling mill have larger deviation after long-time service and the tension control precision is reduced.

In order to solve the technical problem, the invention provides a tension calibration device of a twenty-high rolling mill, which comprises a counterweight frame, a pressing shaft and a counterweight block; one end of the counterweight frame is rotationally connected with a connecting shaft at the inlet of the twenty-high rolling mill; the connecting shaft is positioned between the output shaft of the first speed reducer and the inlet supporting roller; n connecting mechanisms are sequentially arranged on the counterweight frame at preset intervals to connect the counterweight blocks, wherein N is greater than or equal to 1 and is a positive integer; one end of the pressing shaft is connected to the counterweight frame, and the other end of the pressing shaft is pressed on the upper surface of the strip steel on the twenty-high rolling mill through the rotation of the counterweight frame;

the tension calibration device is used for calibrating the mass m of the counterweight frame₁Mass m of the weight member₂The distance L between the connecting mechanism connected with the balancing weight and the connecting shaft, the included angle α between the weight frame and the gravity direction, the included angle theta of the strip steel at the two sides of the pressure shaft and the included angle β between the stress direction of the strip steel reacting on the pressure shaft and the weight frame determine the current actual tension T of the strip steel_actObtaining the set tension T of the twenty-high rolling mill_setAnd the actual tension T_actThe mapping relationship between them.

And the device further comprises a strip steel fixing frame fixedly connected with a platform of the twenty-high rolling mill, one end of the strip steel on the twenty-high rolling mill is fixedly connected to the strip steel fixing frame, and the other end of the strip steel penetrates through a roller set of the twenty-high rolling mill and is coiled to an output shaft of the second speed reducer.

Based on the same inventive concept of the above technical scheme, the invention also provides a tension calibration method of the twenty-high rolling mill, which uses the tension calibration device in the above technical scheme, and the tension calibration method comprises the following steps:

obtaining the set tension T of the current twenty-high rolling mill_setAnd mass m of the weight holder₁；

Determining mass m of a counterweight₂And the connecting position of the balancing weight on the counterweight frame, wherein the distance between the connecting mechanism for connecting the balancing weight and the connecting shaft is L;

determining an included angle α between the weight frame and the gravity direction, an included angle theta of the strip steel on two sides of the pressure shaft, and an included angle β between the stress direction of the strip steel reacting on the pressure shaft and the weight frame;

according to m₁，m₂L, theta, determining the current actual tension T of the strip_act；

Changing set tension T of twenty high rolling mill_setRepeating the steps to obtain a mapping relation between the set tension and the actual tension;

and controlling the production of the strip steel according to the mapping relation.

Optionally, according to m₁，m₂L, theta, determining the current actual tension T of the strip_actThe method specifically comprises the following steps:

according to m₁，m₂L, calculating the stress F' of the strip steel reacting on the pressure shaft according to the moment balance;

determining the current actual tension T of the strip steel according to the stress F' and the stress theta and the force balance_act。

Optionally, calculating a stress F' on the pressing shaft in the reaction of the strip steel according to the moment balance specifically includes:

stress F ═ km₁g+Lm₂g) × sin α/sin β, wherein k is a constant greater than 0.

Optionally, determining the current state of the strip according to the force balanceActual tension T_actThe method specifically comprises the following steps:

according toCalculating the actual tension T_act。

According to the technical scheme, the set tension T of the current twenty-high rolling mill is obtained_setAnd mass m of the weight holder₁Before, still include:

calculating the maximum bending stress of the output shaft of the first speed reducer under the maximum set tension;

and determining that the maximum bending stress is within the allowable stress of the output shaft of the first speed reducer.

According to the technical scheme, the strip steel is a stainless steel strip with the surface roughness within 0.8 mu m.

Through one or more technical schemes of the invention, the invention has the following beneficial effects or advantages:

the invention provides a tension calibration device of a twenty-high rolling mill, which can transmit a quantifiable compressive stress to strip steel through a balance weight frame and a balance weight block and a pressing shaft after the strip steel is tensioned, and then comprehensively determine the actual tension T of the current strip steel according to an angle theta formed by the strip steel under the action of the compressive stress_actAnd a set tension T of the twenty high rolling mill is established_setAnd the actual tension T_actThe mapping relationship between the two; according to the mapping relation, the corresponding actual tension under different set tensions can be determined, so that the proper set tension can be accurately selected in production, the actual tension is controlled to the target tension, the tension control precision of the twenty-high rolling mill is improved, the plate shape quality is guaranteed, and meanwhile, the accuracy of analyzing tension data by technicians is improved.

The foregoing description is only an overview of the technical solutions of the present invention, and the embodiments of the present invention are described below in order to make the technical means of the present invention more clearly understood and to make the above and other objects, features, and advantages of the present invention more clearly understandable.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

FIG. 1 shows a block diagram of a tension calibration apparatus of a twenty-high rolling mill according to one embodiment of the invention;

FIG. 2 shows a schematic view of a tension calibration device mounted on a twenty-high mill connecting shaft according to one embodiment of the invention;

FIG. 3 shows a schematic view of a strip steel according to one embodiment of the invention forming an angle θ on both sides of the pressing axis;

FIG. 4 illustrates a flow diagram of a tension calibration method according to one embodiment of the present invention;

FIG. 5 illustrates a force state diagram of a reducer output shaft according to one embodiment of the invention;

FIG. 6 illustrates a graph of a mapping between set tension and actual tension according to one embodiment of the present invention;

description of reference numerals:

1. an inlet support roll; 2. a connecting shaft; 3. pressing the shaft; 4. a first reducer output shaft; 5. strip steel; 6. a counterweight frame; 7. a balancing weight; 8. a strip steel fixing frame; 9. a high-strength bolt; 10. and a connecting mechanism.

Detailed Description

In order to make the present application more clearly understood by those skilled in the art to which the present application pertains, the following detailed description of the present application is made with reference to the accompanying drawings by way of specific embodiments.

Based on the problem that the deviation between the set tension and the actual tension of the twenty-high rolling mill is increased after the twenty-high rolling mill is in service for a long time, and the plate strip rolling is influenced, through research, in an optional embodiment, as shown in fig. 1 to 2, the invention provides a tension calibration device of the twenty-high rolling mill, which comprises a counterweight frame 6, a pressing shaft 3 and a counterweight block 7; one end of the counterweight frame 6 is rotationally connected with the connecting shaft 2 at the inlet of the twenty-high rolling mill; the connecting shaft 2 is positioned between the first reducer output shaft 4 and the inlet supporting roller 1; n connecting mechanisms 10 are sequentially arranged on the counterweight frame 6 at preset intervals to connect the counterweight blocks 7, wherein N is greater than or equal to 1 and is a positive integer; one end of the pressing shaft 3 is connected to the counterweight bracket 6, and the other end of the pressing shaft is pressed on the upper surface of the strip steel 5 on the twenty-high rolling mill through the rotation of the counterweight bracket 6;

the tension calibration device is used for calibrating the mass m of the counterweight frame 6₁Mass m of weight member 7₂The distance L between the connecting mechanism 10 connected with the balancing weight 7 and the connecting shaft 2, the included angle α between the weight frame 6 and the gravity direction, the included angle theta of the strip steel 5 at the two sides of the pressure shaft 3 and the included angle β between the stress direction of the strip steel 5 reacting on the pressure shaft 3 and the weight frame 6 determine the current actual tension T of the strip steel 5_actObtaining the set tension T of the twenty-high rolling mill_setAnd the actual tension T_actThe mapping relationship between them.

Specifically, the tension calibration device provided in this embodiment is a device that, after tension is established in a twenty-high rolling mill, a quantifiable compressive stress is generated on a strip steel through a pressing shaft according to weights of a counterweight frame and a counterweight block, so that an included angle θ (shown in fig. 3) is formed between the strip steel with the established tension and two sides of the pressing shaft, and then the actual tension on the strip steel at that time can be calculated by combining values of the compressive stress.

In the embodiment, the counterweight housing 6 is a metal bracket with certain length and width designed according to the specification of the twenty-high rolling mill, and one end of the counterweight housing 6 is rotatably connected to the connecting shaft 2 on the twenty-high rolling mill; specifically, a speed reducer is respectively arranged at an inlet and an outlet of the twenty-high rolling mill, an inlet supporting roller 1 is arranged near a roller inlet where strip steel 5 enters the twenty-high rolling mill, and a counterweight frame 6 is rotatably connected to a connecting shaft 2 between an output shaft of the speed reducer and the inlet supporting roller 1 and can freely rotate around the connecting shaft 2 in the vertical direction. A plurality of connecting mechanisms 10 can be sequentially arranged on the counterweight frame 6 at certain intervals, and the connecting mechanisms 10 can be connecting holes or connecting beams for hanging the counterweight blocks 7, which is not particularly limited herein; the space between the connecting mechanisms 10 is configured according to specific requirements, and the connecting mechanisms are used for installing or hanging the balancing weight 7; the weight 7 may be a conventional counterweight. The pressing shaft 3 is a structure similar to a pressing roller and arranged on the weight frame 6, the position of the pressing shaft is close to one end, connected with the twenty-high rolling mill connecting shaft 2, of the weight frame 6, the pressing shaft 3 is pressed on the surface of the strip steel 5 through the rotation of the weight frame 6 around the connecting shaft 2 in the vertical direction, and at the moment, the weight frame 6 and the balancing weight 7 apply pressing stress to the strip steel 5 under the action of gravity. The pressing shaft 3 is connected with the balance weight frame 6 through a bearing, and the strip steel 5 can drive the pressing shaft 3 to synchronously rotate around the axis of the pressing shaft 3 when in operation, so that the strip steel 5 is prevented from being scratched in the process of calibrating the tension.

When the tension calibration is carried out, different set tensions T are arranged on the twenty-high rolling mill_setNext, the pressure stress of the pressing shaft 3 acting on the strip steel 5 is calculated and adjusted by adjusting the mass or the installation position of the counterweight block 7 and combining the weight of the counterweight frame 6, so that the strip steel 5 forms different included angles theta at two sides of the pressing shaft 3, and different set tension T can be determined according to the current theta_setActual tension T to which the lower strip 5 is subjected_actThereby establishing the set tension T of the complete twenty-high rolling mill_setAnd the actual tension T_actThe mapping relationship between them.

The embodiment provides a tension calibration device of a twenty-high rolling mill, which can transmit a quantifiable compressive stress to strip steel through a balance weight frame and a balance weight block through a pressing shaft after the strip steel is tensioned, and then comprehensively determine the actual tension T of the current strip steel according to an angle theta formed by the strip steel under the action of the compressive stress_actAnd a set tension T of the twenty high rolling mill is established_setAnd the actual tension T_actThe mapping relationship between the two; according to the mapping relation, the corresponding actual tension under different set tensions can be determined, so that the proper set tension can be accurately selected in production, the actual tension is controlled to the target tension, the tension control precision of the twenty-high rolling mill is improved, the plate shape quality is guaranteed, and meanwhile, the accuracy of analyzing tension data by technicians is improved.

Optionally, when calibrating the tension, the strip steel at the head of the twenty-rolling mill can be fixed by using a strip steel fixing frame, so that the stability of the strip steel in the tension calibration process is improved, and the accuracy of the tension calibration is improved. Therefore, based on the same inventive concept of the above embodiment, as shown in fig. 2, the tension calibration device further includes a strip steel fixing frame fixedly connected to the platform of the twenty-high rolling mill, one end of the strip steel 5 on the twenty-high rolling mill is fixedly connected to the strip steel fixing frame 8, and the other end of the strip steel passes through the roll set of the twenty-high rolling mill and is wound to the output shaft of the second reducer.

Specifically, the strip steel fixing frame 8 is a welding structure designed according to the angle between the twenty-high rolling mill platform and the strip steel 5. And chamfering R5 is carried out on two sharp corners of the strip steel 5 in contact with the strip steel, and the top end of the strip steel forms an angle of 15 degrees with the platform. The strip steel fixing frame 8 is fully welded with the twenty-high rolling mill platform to ensure that the strip steel 5 bears the maximum tension. Then the strip steel 5 is pressed by a cover plate and fixed on a strip steel fixing frame 8 by 6M 12 high-strength bolts 9. Therefore, the stability of the strip steel 5 in the tension calibration process can be ensured.

In the above group of embodiments, a tension calibration device for calibrating tension of a twenty-high rolling mill is provided, and in the following embodiments, based on the same inventive concept of the above embodiments, as shown in fig. 4, a method for calibrating tension of a twenty-high rolling mill by using the tension calibration device in the above embodiments is provided, which specifically includes:

s1: obtaining the set tension T of the current twenty-high rolling mill_setAnd mass m of the weight holder₁；

S2: determining mass m of a counterweight₂And the connecting position of the balancing weight on the counterweight frame, wherein the distance between the connecting mechanism for connecting the balancing weight and the connecting shaft is L;

s3, determining an included angle α between the weight frame and the gravity direction, an included angle theta of the strip steel on two sides of the pressure shaft and an included angle β between the stress direction of the strip steel reacting on the pressure shaft and the weight frame;

s4: according to m₁，m₂L, theta, determining the current actual tension T of the strip_act；

S5: changing set tension T of twenty high rolling mill_setRepeating the steps to obtain a mapping relation between the set tension and the actual tension;

s6: and controlling the production of the strip steel according to the mapping relation.

In the tension calibration method provided by the embodiment, the tension T is set at different settings of the twenty-high rolling mill_setBy adjusting mass m of the weight₂Or mounting location L, in combination with the weight m of the weight rack itself₁Calculating and adjusting the pressure stress of the press shaft on the strip steel, so that the strip steel forms different included angles theta at two sides of the press shaft, and determining different set tension T according to the current theta_setActual tension T suffered by lower strip steel_actThereby establishing the set tension T of the complete twenty-high rolling mill_setAnd the actual tension T_actThe mapping relationship between them. After the mapping relation between the set tension and the actual tension is obtained, the actual tension corresponding to the twenty-high rolling mill unit under different set tensions can be determined, so that the proper set tension can be accurately selected in production, the actual tension is controlled to the target tension, the tension control precision of the twenty-high rolling mill is improved, the plate shape quality is guaranteed, and meanwhile, the accuracy of analyzing tension data by technicians is improved.

Based on the same inventive concept of the previous embodiment, in yet another alternative embodiment, the S4: according to m₁，m₂L, theta, determining the current actual tension T of the strip_actThe method specifically comprises the following steps:

s41: according to m₁，m₂L, calculating the stress F' of the strip steel reacting on the pressure shaft according to the moment balance;

s42: determining the current actual tension T of the strip steel according to the stress F' and the stress theta and the force balance_act。

Further, as shown in fig. 2, in S41: according to the moment balance, the stress F' of the strip steel reacting on the press shaft is calculated, and the method specifically comprises the following steps:

stress F ═ km₁g+Lm₂g) × sin α/sin β, wherein k is a constant greater than 0.

The calculation formula of the strip steel reaction force is a calculation formula which is obtained by establishing an equation according to a moment balance principle and processing the equation according to the pressure stress applied to the strip steel by the balance weight frame and the balance weight through the pressure shaft and the reaction force applied to the pressure shaft by the strip steel under the tension action. The value of the constant k is comprehensively determined according to the gravity center position (related to the length and the shape of the weight frame) of the weight frame.

Further, as shown in fig. 3, S42: determining the current actual tension T of the strip steel according to the force balance_actThe method specifically comprises the following steps:

according toCalculating the actual tension T_act。

Through the relation between the moment balance and the acting force balance, the current actual tension of the strip steel can be accurately calculated, namely the twenty-high rolling mill is at the set tension T_setActual tension T actually output_act. Optionally, the strip steel for calibrating the tension can be a stainless steel strip with the thickness of 0.6-1.0 mm and the surface roughness Ra of less than 0.8 μm, such as a 304 stainless steel soft strip.

Before calibrating the tension, checking whether the maximum bending stress borne by the output shaft of the speed reducer exceeds a safety value or not, and ensuring the safety of the rolling mill set in the tension calibration process. Therefore, based on the same inventive concept as the previous embodiment, in other alternative embodiments, at S1: obtaining the set tension T of the current twenty-high rolling mill_setAnd mass m of the weight holder₁Before, still include:

calculating the maximum bending stress of the output shaft of the first speed reducer under the maximum set tension;

and determining that the maximum bending stress is within the allowable stress of the output shaft of the first speed reducer.

The bending stress comprises bending normal stress and bending shear stress, the bending normal stress and the bending shear stress are guaranteed not to exceed the allowable stress value of the output shaft of the speed reducer under the maximum set tension, and the material of the output shaft of the speed reducer is Q345. Specifically, fig. 5 shows the stress condition of the output shaft of the speed reducer under the tension of the strip steel, when the radius of the output shaft of the speed reducer is r, the width b of the strip steel, the thickness h of the strip steel, and the actual tension T of the twenty-high rolling mill is 600-3000N, as shown in fig. 5, the stress condition is obtained according to the balance equation in the coiling process of the cold-rolled strip

P·r＝σ₀h (1)

T＝σ₀hb (2)

Wherein σ₀The bending stress per unit length of the strip steel acting on the output shaft of the speed reducer.

From (1) and (2) can be obtained:

P＝T/br (3)

when T is the maximum value, the output shaft of the speed reducer is subjected to the maximum pressure stress Pmax. The output shaft of the speed reducer is equivalent to a cantilever beam, when the middle part of the speed reducer is subjected to uniform pressure P, the torque and the shearing force at the fixed end are the maximum, Mmax is calculated, the maximum bending moment and torsion resistant section coefficient Wz, the maximum bending normal stress [ sigma ] and the allowable shearing stress [ tau ] are obtained by looking up a table. Firstly, ensuring that the maximum bending normal stress sigma max is Mmax/Wz and is not more than sigma; secondly, the maximum pressure Fmax to which the fixed end of the cantilever beam is subjected is Pmax b ω r, wherein ω is a central angle corresponding to the contact area of the strip steel on the output shaft of the speed reducer, the section area A of the cantilever beam allows the shear stress [ tau ], and therefore the maximum bending shear stress tau max is not less than Fmax/A [ tau ] should be ensured.

By the speed reducer output shaft checking method, the bending normal stress and the bending shear stress borne by the speed reducer output shaft under the maximum set tension are controlled within a safety range, and the safety and the stability of the twenty-high rolling mill in the tension calibration process can be improved.

Based on the same inventive concept of the above embodiments, in the following embodiment, the application of the above method will be described in detail with reference to a specific twenty-high rolling mill train.

The twenty-high rolling mill used in a rolling center laboratory of a university is designed and manufactured in the fifty-six decades, and has the advantages of low assembly precision, poor stability and inaccurate actual tension. In order to calibrate the actual tension of the twenty-high rolling mill under different set tensions, the tension calibration device and the tension calibration method provided in the foregoing embodiments are used for calibrating the actual tension. Firstly, the specification of the counterweight frame is designed according to the matched size of a twenty-high rolling mill in a rolling center laboratory: see fig. 1, weight carrier 6 length960mm, 200mm in width; 6 connecting beams are arranged on the counterweight frame 6 and used for hanging counterweight weights; according to the distance from the connecting shaft 2, referring to fig. 2, the distance from each connecting beam to the connecting shaft 2 is a, b, c, d, e and f respectively according to the sequence from near to far; wherein the spacing between a and f is 160 mm; the weight of the weight frame 6 is m₁Two counter weights (weight m) were used as the counter weight 7 (12.5 Kg) and prepared₂₁＝20Kg，m₂₂＝40Kg。

The counterweight housing 6 is rotationally connected with the connecting shaft 2 near the inlet of the twenty-high rolling mill, when different counterweight weights or connecting beams at different positions on the counterweight housing 6 are selected, the compressive stress of the pressing shaft 3 acting on the strip steel 5 is different, and the angle theta of the strip steel 5 at the two sides of the pressing shaft 3 changes accordingly; the self gravity m of the counterweight frame 6₁g direction and counterweight weight gravity m₂₁g or m₂₂g direction and the balance weight 6 form an acute angle α, the strip steel 5 reacts against the supporting force F of the press shaft 3 and the balance weight 6 form an acute angle β, when calibrating the tension, a 304 stainless steel soft belt with the specification of 0.8mm × 100mm and the surface roughness Ra of less than 0.8 mu M can be selected, the strip steel fixing frame 8 is a welding structure designed according to the angle between the twenty-high rolling mill platform and the strip steel 5, the strip steel fixing frame 8 and the twenty-high rolling mill platform are fully welded, the maximum tension of the experimental strip steel 5 can be borne, chamfering R5 is conducted on two sharp angles where the strip steel 5 is in contact, the top end of the strip steel 5 forms an angle of 15 degrees with the platform, the head of the strip steel 5 is fixed on the strip steel fixing frame 8, after the strip steel 5 is pressed by a cover plate, 6M 12 high-strength bolts 9 are used for fixing on the strip steel fixing frame 8, optionally, after the preparation work is finished, the checking of the output shaft can be carried out, and the maximum bending stress and the bending.

The tension calibration step is then carried out, as shown in fig. 2, with the weight m of the weight frame 6 itself₁12.5Kg, center of gravity at point c, and counterweight m₂₁＝20Kg，m₂₂The included angle between the supporting stress F 'of the 40 Kg. steel strip 5 acting on the pressing shaft 3 and the counterweight frame 6 is α, the included angle between the gravity of the counterweight frame 6 and the counterweight 7 and the counterweight frame 6 is β, and when the counterweight weight is used, the supporting stress F' acts on the pressing shaft 3, and the included angle between the gravity of the counterweight frame 6 and the counterweight 7 and the counterweight frame 6m₂₁Or m₂₂When the balance weight frame 6 is at different positions, the press shaft 3 slightly changes the included angle theta formed by the strip steel 5 at the two sides of the balance weight frame 6, so that the supporting stress F' of the strip steel 5 acting on the press shaft 3 is determined according to the quantifiable gravity and the actual theta angle of the balance weight frame 6 and the balance weight 7, and the current actual tension T of the strip steel 5 is further calculated_act。

In this embodiment, when counterweight weights with different weights are selected and connected to different positions on the counterweight frame, a specific calculation method of the actual tension corresponding to the currently set tension of the twenty-high rolling mill is as follows:

(1) without counterweight, as shown in FIGS. 2-3, the steel belts on both sides of the pressing shaft form an included angle theta₁The included angle between the stress F' and the weight frame is β₁Gravity m of the balance weight rack₁g and the weight frame form an included angle of α₁The connecting shaft connected with the counterweight housing is used as a shaft point, and according to the moment balance principle, the weight balance device is obtained:

F₁'＝3m₁g×sinα₁/sinβ₁(4)

wherein, constant k is 3 according to current weight frame and counter weight specification and weight actual definite, then according to the force balance, obtains the actual tension of belted steel this moment:

(2) mounting mass m at point a₂₁The weight (i.e. the connecting beam with a distance L from the connecting shaft) is 20Kg, and the included angle formed by the steel belts at the two sides of the pressing shaft is theta_a21The included angle between the stress F' and the weight frame is β_a21Gravity m of the balance weight rack₁g. Counterweight weight gravity m₂g and the weight frame form an included angle of α_a21The connecting shaft connected with the counterweight housing is used as a shaft point, and according to the moment balance principle:

F_a21'＝(3m₁g+am₂₁g)×sinα_a21/sinβ_a21(6)

then, according to the force balance, obtaining the actual tension of the strip steel at the moment:

(3) mounting mass m at point b₂₁The weight (i.e. the connecting beam with the distance L b from the connecting shaft) is 20Kg, and the included angle formed by the steel belts at the two sides of the pressing shaft is theta_b21The included angle between the stress F' and the weight frame is β_b21Gravity m of the balance weight rack₁g. Counterweight weight gravity m₂g and the weight frame form an included angle of α_b21The connecting shaft connected with the counterweight housing is used as a shaft point, and according to the moment balance principle:

F_b21'＝(3m₁g+bm₂₁g)×sinα_b21/sinβ_b21(8)

then, according to the force balance, obtaining the actual tension of the strip steel at the moment:

(4) mounting mass m at point c₂₁The weight (namely the connecting beam with the distance L being c from the connecting shaft) is configured to be 20Kg, and the included angle formed by the steel belts at the two sides of the pressing shaft is theta_c21The included angle between the stress F' and the weight frame is β_c21Gravity m of the balance weight rack₁g. Counterweight weight gravity m₂g and the weight frame form an included angle of α_c21The connecting shaft connected with the counterweight housing is used as a shaft point, and according to the moment balance principle:

F_c21'＝(3m₁g+cm₂₁g)×sinα_c21/sinβ_c21(10)

then, according to the force balance, obtaining the actual tension of the strip steel at the moment:

(5) mounting mass m at point d₂₁20Kg of configuration weight (i.e. a connecting beam with a distance L d from the connecting shaft), and the included angle formed by the steel belts at the two sides of the pressing shaft is theta_d21The included angle between the stress F' and the weight frame is β_d21Gravity m of the balance weight rack₁g、Counterweight weight gravity m₂g and the weight frame form an included angle of α_d21The connecting shaft connected with the counterweight housing is used as a shaft point, and according to the moment balance principle:

F_d21'＝(3m₁g+dm₂₁g)×sinα_d21/sinβ_d21(12)

then, according to the force balance, obtaining the actual tension of the strip steel at the moment:

(6) mounting mass m at point e₂₁The weight (i.e. the connecting beam with the distance L equal to e from the connecting shaft) is 20Kg, and the included angle formed by the steel belts at the two sides of the pressing shaft is theta_e21The included angle between the stress F' and the weight frame is β_e21Gravity m of the balance weight rack₁g. Counterweight weight gravity m₂g and the weight frame form an included angle of α_e21The connecting shaft connected with the counterweight housing is used as a shaft point, and according to the moment balance principle:

F_e21'＝(3m₁g+em₂₁g)×sinα_e21/sinβ_e21(14)

then, according to the force balance, obtaining the actual tension of the strip steel at the moment:

(7) mounting mass m at point f₂₁20Kg of configuration weight (i.e. a connecting beam with a distance L f from the connecting shaft), and the included angle formed by the steel belts at the two sides of the pressing shaft is theta_f21The included angle between the stress F' and the weight frame is β_f21Gravity m of the balance weight rack₁g. Counterweight weight gravity m₂g and the weight frame form an included angle of α_f21The connecting shaft connected with the counterweight housing is used as a shaft point, and according to the moment balance principle:

F_f21'＝(3m₁g+fm₂₁g)×sinα_f21/sinβ_f21(16)

then, according to the force balance, obtaining the actual tension of the strip steel at the moment:

(8) mounting mass m at point a₂₂A weight (i.e. a connecting beam with a distance L from the connecting shaft) of 40Kg, and the included angle formed by the steel belts at the two sides of the pressing shaft is theta_a22The included angle between the stress F' and the weight frame is β_a22Gravity m of the balance weight rack₁g. Counterweight weight gravity m₂g and the weight frame form an included angle of α_a22The connecting shaft connected with the counterweight housing is used as a shaft point, and according to the moment balance principle:

F_a22'＝(3m₁g+am₂₂g)×sinα_a22/sinβ_a22(18)

then, according to the force balance, obtaining the actual tension of the strip steel at the moment:

(9) mounting mass m at point b₂₂A weight (i.e. a connecting beam with a distance L b from the connecting shaft) of 40Kg, wherein the included angle formed by the steel belts at two sides of the pressing shaft is theta_b22The included angle between the stress F' and the weight frame is β_b22Gravity m of the balance weight rack₁g. Counterweight weight gravity m₂g and the weight frame form an included angle of α_b22The connecting shaft connected with the counterweight housing is used as a shaft point, and according to the moment balance principle:

F_b22'＝(3m₁g+bm₂₂g)×sinα_b22/sinβ_b22(20)

then, according to the force balance, obtaining the actual tension of the strip steel at the moment:

(10) mounting mass m at point c₂₂40Kg of configuration weight (i.e. a connecting beam with a distance L ═ c from the connecting shaft), and the included angle formed by the steel belts at the two sides of the pressing shaft is theta_c22The included angle between the stress F' and the weight frame is β_c22Gravity m of the balance weight rack₁g. Counterweight weight gravity m₂g and the weight frame form an included angle of α_c22The connecting shaft connected with the counterweight housing is used as a shaft point, and according to the moment balance principle:

F_c22'＝(3m₁g+cm₂₂g)×sinα_c22/sinβ_c22(22)

then, according to the force balance, obtaining the actual tension of the strip steel at the moment:

(11) mounting mass m at point d₂₂The weight (i.e. the connecting beam with the distance L d from the connecting shaft) is arranged at 40Kg, and the included angle formed by the steel belts at the two sides of the pressing shaft is theta_d22The included angle between the stress F' and the weight frame is β_d22Gravity m of the balance weight rack₁g. Counterweight weight gravity m₂g and the weight frame form an included angle of α_d22The connecting shaft connected with the counterweight housing is used as a shaft point, and according to the moment balance principle:

F_d22'＝(3m₁g+dm₂₂g)×sinα_d22/sinβ_d22(24)

then, according to the force balance, obtaining the actual tension of the strip steel at the moment:

(12) mounting mass m at point e₂₂The weight (i.e. the connecting beam with the distance L equal to e from the connecting shaft) is arranged at 40Kg, and the included angle formed by the steel belts at the two sides of the pressing shaft is theta_e22The included angle between the stress F' and the weight frame is β_e22Gravity m of the balance weight rack₁g. Counterweight weight gravity m₂g and the weight frame form an included angle of α_e22The connecting shaft connected with the counterweight housing is used as a shaft point, and according to the moment balance principle:

F_e22'＝(3m₁g+em₂₂g)×sinα_e22/sinβ_e22(26)

then, according to the force balance, obtaining the actual tension of the strip steel at the moment:

(13) mounting mass m at point f₂₂40Kg of configuration weight (i.e. a connecting beam with a distance L f from the connecting shaft), and the included angle formed by the steel belts at the two sides of the pressing shaft is theta_f22The included angle between the stress F' and the weight frame is β_f22Gravity m of the balance weight rack₁g. Counterweight weight gravity m₂g and the weight frame form an included angle of α_f22The connecting shaft connected with the counterweight housing is used as a shaft point, and according to the moment balance principle:

F_f22'＝(3m₁g+fm₂₂g)×sinα_f22/sinβ_f22(28)

then, according to the force balance, obtaining the actual tension of the strip steel at the moment:

in conclusion, the strip steel tension T can be respectively calculated when the balancing weight is not placed or is placed at different positions₁，T_a21，T_b21，T_c21，T_d21，T_e21，T_f21，T_a22，T_b22，T_c22，T_d22，T_e23，T_f24. In the actual calibration, according to the requirement, part of the above schemes can be selectively implemented or all the above schemes can be implemented, the obtained tension data T is processed, for example, the mean value processing is carried out, and the set tension T of the current twenty-high rolling mill is comprehensively determined_setCorresponding T under value_act。

Further, in the measurement experiment, 5-8 layers of strip steel are coiled by an extension shaft of a speed reducer on the other side of the twenty-high rolling mill, and the rolling mill sets tension T_setCan be respectively 600N, 1000N, 1500N, 2000N, 2500N, 3000N, 3600N, 4200N, 4800N, 5400N, 6000N and 7200N; according to the steps, the actual tension T of the corresponding strip steel under each set tension is determined in sequence_actTo obtain the set tension T_setAnd the actual tension T_actMapping the mapping relation between the tension and the tension, and drawing and fitting the mapping relation in drawing software to obtain the set tension T_setAnd the actual tension T_actThe mapping curve between them is shown in fig. 6. According to the mapping curve, technicians can be guided to accurately control the target tension of the strip steel production; for example, when the current set tension is 3600N, looking up the curve can find that the corresponding actual tension is 4000N; when the target tension required by the technician is 4800N, it can be seen by looking up the curve that the target tension can be obtained by adjusting the set tension to 4600N. Therefore, the tension calibration method can improve the precision of strip steel production control, ensure the quality of plate shape, and guide technicians to obtain more accurate actual tension data during the analysis and rolling.

Through one or more embodiments of the present invention, the present invention has the following advantageous effects or advantages:

the invention provides a tension calibration device of a twenty-high rolling mill, which can transmit a quantifiable compressive stress to strip steel through a balance weight frame and a balance weight block and a pressing shaft after the strip steel is tensioned, and then comprehensively determine the actual tension T of the current strip steel according to an angle theta formed by the strip steel under the action of the compressive stress_actAnd a set tension T of the twenty high rolling mill is established_setAnd the actual tension T_actThe mapping relationship between the two; according to the mapping relation, the corresponding actual tension under different set tensions can be determined, so that the proper set tension can be accurately selected in production, the actual tension is controlled to the target tension, the tension control precision of the twenty-high rolling mill is improved, the plate shape quality is guaranteed, and meanwhile, the accuracy of analyzing tension data by technicians is improved.

While the preferred embodiments of the present application have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all alterations and modifications as fall within the scope of the application.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.