Production method of high-speed wire rod pinch roll exceeding design limit large specification

Abstract

The invention relates to a production method of a high-speed wire rod pinch roll exceeding the design limit large specification, and belongs to the technical field of high-speed wire rod rolling methods. According to the technical scheme, pinch rolls are additionally arranged at the positions of No.13 rolling mills on a production line; an existing rolling mill is adopted as a newly-added pinch roll, the hole pattern of the pinch roll is designed on the roll according to the material pattern, and the roll gap of the pinch roll is adjusted through a rolling mill adjusting mechanism; in the production process of a product with an extremely large specification, the speed and the time sequence of the newly-added pinch roll and the original pinch roll before finish rolling of a production line are subjected to electrical interlocking control, and the double pinch rolls before reducing and sizing are formed. The device has the beneficial effects that the tension and the movement stability of a rolled piece in an idle interval from medium rolling to reducing and sizing rolling mill are ensured, the problems of loop rising and knotting are successfully solved, production accidents are eliminated, the equipment damage and the loss of manpower and material resources caused by the problems are completely eradicated, the bottleneck problem of large-specification production is solved, and a continuous and stable production order is formed.

Description

Technical Field

[0001] The invention relates to a method for producing a pinch roller for high-speed wire rods with large specifications exceeding the design limit, and belongs to the technical field of high-speed wire rod rolling methods. Background Art

[0002] As the market division of labor continues to refine, user products have higher requirements for the near-final shape of raw materials, leading the processing production line to continuously break through the limit specifications. In modern high-speed wire production, due to the advantages of long coil length and no joints, the demand for large-size coils in the machining industry is increasing, and the maximum size of the product has also changed from the original Widen to Recently, we have gradually developed ultra-limited specifications In the development and production of these extreme large specifications, due to the characteristics of the wire production line: the distance between the pre-finished product mill and the finished product sizing mill is as long as 154 meters (see Figure 1 High-speed wire production process layout diagram), the empty spacing is too long, the head power is insufficient during the transportation of the rolled piece, and the end has serious bending force problems in the empty part, resulting in frequent production accidents such as knotting and sleeve untying. In the original design, there was a pinch roll device in front of the finishing mill, but because the distance was too far, it could not make up for the power transmission problem in the empty part after the intermediate rolling, and normal continuous production could not be achieved. Summary of the invention

[0003] The purpose of the present invention is to provide a method for producing pinch rollers of large specifications of high-speed wire rods exceeding the design limit. By adding a new pinch roller device after the 2# flying shear of the intermediate rolling mill, a double pinch roller device is formed with the original pinch rollers before the finishing rolling mill, and corresponding interlocking control is added to ensure the tension and movement stability of the rolled piece in the empty section from the intermediate rolling mill to the sizing mill, successfully solve the problems of sheathing and knotting, eliminate production accidents, prevent equipment damage and loss of manpower and material resources caused by them, solve the bottleneck problem of producing large specifications, and form a continuous and stable production order; on this basis, super-limit specifications of wire rods are successfully developed, the group spacing of wire rod products is widened, and the production specification limit of the same type of equipment production line is broken through, which contributes to the development of the entire high-speed wire rod industry and effectively solves the above-mentioned problems existing in the background technology.

[0004] The technical solution of the present invention is: a method for producing a large-size pinch roller for high-speed wire that exceeds the design limit, comprising the following steps:

[0005] (1) Analysis of production problems of ultra-large specifications and selection of the location of additional pinch rolls. Pinch rolls were added to the NO.13 rolling mill on the production line.

[0006] (2) Adding pinch rolls, using the existing rolling mill as the new pinch rolls, designing the pinch roll hole type on the rolls according to the material type, and adjusting the pinch roll gap through the rolling mill adjustment mechanism;

[0007] (3) Electrical control of the speed and interlocking of double pinch rollers. During the production of extremely large-size products, the speed and timing of the newly added pinch rollers and the original pinch rollers before finishing rolling of the production line are electrically interlocked to form double pinch rollers before sizing.

[0008] In the step (1), the bending of the pressure rod is mechanically analyzed using the Euler formula in material mechanics, and the rolled piece located at the 2# flying shear is regarded as a section of the pressure rod. If the rolled piece is subjected to a large thrust and becomes bent, it will rush out of the guide groove after the shearing, causing a steel pile accident here, thereby determining the position of the newly added pinch rollers to be after the 2# flying shear, at the position of the NO. 13 rolling mill.

[0009] In the step (2), according to the NO.12 rack material type Φ32.4mm circle, the pinch hole type adopts an open groove top arc with a radius R of 16.5mm, the hole side wall adopts 35°, and the hole corner radius adopts r as a transition of 2mm; the pinch roller gap is designed to be an adjustable structure, and the adjustment method of the rolling mill gap is used. Taking into account the bounce of the rolling mill and the deviation of the material, when the roll gap is set, the adjustment value is 0.5mm smaller than the rolled piece.

[0010] In the step (3), the control sequence and speed of the double pinch rollers are based on the NO.12 mill. 10 seconds after the head of the rolled piece exits the NO.12 mill, the newly added pinch roller performs a pinch closing action; 17 seconds after the head of the rolled piece exits the NO.12 mill, the pinch roller before finishing rolling performs a pinch closing action; after the head of the rolled piece bites into the sizing unit, the pinch roller before finishing rolling performs an opening action, and the newly added pinch roller ensures the pinching state; the set speed of the newly added pinch roller is 5-7% ahead of the NO.12 mill, and the speed of the pinch roller before finishing rolling is changed to 8-13% ahead of the new pinch roller, so that the rolled piece forms a micro-tension between the two pinch rollers to avoid steel piling accidents; the continuous rolling speed matching relationship between the double pinch rollers is adjusted by changing the lead coefficient.

[0011] The beneficial effects of the present invention are as follows: by adding a new set of pinch roller device after the 2# flying shear of the intermediate rolling mill, a double pinch roller device is formed with the original pinch roller before the finishing rolling mill, and corresponding interlocking control is added to ensure the tension and movement stability of the rolled piece in the empty passage section from the intermediate rolling mill to the sizing mill, successfully solve the problems of sheathing and knotting, eliminate production accidents, prevent equipment damage and loss of manpower and material resources caused by them, solve the bottleneck problem of producing large specifications, and form a continuous and stable production order; on this basis, the super-limit specifications of wire rods are successfully developed, the group spacing of wire rod products is widened, and the production specification limits of production lines with the same type of equipment are broken through, which contributes to the development of the entire high-speed wire rod industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1It is a process layout diagram of the wire rod double pinch roller of the present invention;

[0013] Figure 2 It is a hole structure diagram of the newly added pinch roller of the present invention;

[0014] Figure 3 It is a logic diagram of the electric control program of the double pinch rollers of the present invention;

[0015] In the figure: heating furnace 1, descaling machine 2, guide roller before roughing 3, roughing mill unit 4, 1# flying shear 5, intermediate rolling mill unit 6, 2# flying shear 7, pre-finishing mill unit 8, side looper 9, Morgan pre-finishing mill unit 10, 1# water-cooling section 11, pinch roller before finishing 12, switch 13, breaking shear 14, finishing mill unit 15, 2# water-cooling section 16, sizing unit 17, 3# water-cooling section 18, Stelmor cooling line 19, PF line 20, unloading coil station 21, baling machine 22, double core rod 23, collecting reel 24, laying head 25, pinch roller before finishing 26, diameter gauge 27, newly added pinch roller 28, groove top arc 281, hole fillet 282, hole side wall 283, roll gap 284. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solutions and advantages of the invention implementation cases clearer, the technical solutions in the implementation cases of the present invention will be clearly and completely described below in conjunction with the drawings in the implementation cases. Obviously, the implementation cases described are only a small part of the implementation cases of the present invention, rather than all the implementation cases. Based on the implementation cases in the present invention, all other implementation cases obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0017] A method for producing a pinch roller with large specifications exceeding the design limit for high-speed wire rods comprises the following steps:

[0018] (1) Analysis of production problems of ultra-large specifications and selection of the location of additional pinch rolls. Pinch rolls were added to the NO.13 rolling mill on the production line.

[0019] (2) Adding pinch rolls, using the existing rolling mill as the new pinch rolls, designing the pinch roll hole type on the rolls according to the material type, and adjusting the pinch roll gap through the rolling mill adjustment mechanism;

[0020] (3) Electrical control of the speed and interlocking of double pinch rollers. During the production of extremely large-size products, the speed and timing of the newly added pinch rollers and the original pinch rollers before finishing rolling of the production line are electrically interlocked to form double pinch rollers before sizing.

[0021] In the step (1), the bending of the pressure rod is mechanically analyzed using the Euler formula in material mechanics, and the rolled piece located at the 2# flying shear is regarded as a section of the pressure rod. If the rolled piece is subjected to a large thrust and becomes bent, it will rush out of the guide groove after the shearing, causing a steel pile accident here, thereby determining the position of the newly added pinch rollers to be after the 2# flying shear, at the position of the NO. 13 rolling mill.

[0022] In the step (2), according to the NO.12 rack material type Φ32.4mm circle, the pinch hole type adopts an open groove top arc with a radius R of 16.5mm, the hole side wall adopts 35°, and the hole corner radius adopts r as a transition of 2mm; the pinch roller gap is designed to be an adjustable structure, and the adjustment method of the rolling mill gap is used. Taking into account the bounce of the rolling mill and the deviation of the material, when the roll gap is set, the adjustment value is 0.5mm smaller than the rolled piece.

[0023] In the step (3), the control sequence and speed of the double pinch rollers are based on the NO.12 mill. 10 seconds after the head of the rolled piece exits the NO.12 mill, the newly added pinch roller performs a pinch closing action; 17 seconds after the head of the rolled piece exits the NO.12 mill, the pinch roller before finishing rolling performs a pinch closing action; after the head of the rolled piece bites into the sizing unit, the pinch roller before finishing rolling performs an opening action, and the newly added pinch roller ensures the pinching state; the set speed of the newly added pinch roller is 5-7% ahead of the NO.12 mill, and the speed of the pinch roller before finishing rolling is changed to 8-13% ahead of the new pinch roller, so that the rolled piece forms a micro-tension between the two pinch rollers to avoid steel piling accidents; the continuous rolling speed matching relationship between the double pinch rollers is adjusted by changing the lead coefficient.

[0024] like Figure 1 , because the wire rod production exceeds the limit specification (diameter greater than 26mm) and the size is large, there are many empty racks, and the rolled pieces from rack 12 (the last rack of the intermediate rolling) to rack 27 (the first rack of the sizing reduction) are all empty, the transportation distance is long (154m), the operation resistance is large, and steel pile accidents are very likely to occur. In order to ensure the smooth transportation of rolled pieces, the 13th rolling mill (the first rack of the pre-finishing rolling) is used as the pinch roller for intermediate pinching to ensure that the rolled pieces run normally before entering the sizing reduction mill. Universal rolling rollers are used, and the hole type of the processing rollers is designed to ensure the normal bite of the rolling mill; the 13th rolling mill is compiled as the pinch roller electrical control program, which is combined with the original electrical control of the pinch roller before finishing rolling to form a double pinch roller control process.

[0025] In order to solve the problem of large mill spacing in the production of large specifications, easy to push the steel, and scratches on the surface, 13 mills were selected as pinch rolls, the pass type of the pinch rolls was designed according to the material type, and the electronic control program of the mill as the pinch roll was written to form a process design of double pinch rolls before sizing to ensure that the rolled piece passes the rolling smoothly;

[0026] The technical solution of the present invention is:

[0027] On the production line, the NO.13 rolling mill position is selected to add pinch rollers, and the existing rolling mill is used as the newly added pinch rollers. The pinch roller hole type is designed on the roller according to the material type, and the pinch roller gap is adjusted through the rolling mill adjustment mechanism. In the production process of extreme large-size products, the corresponding control sequence is formulated, and the pinch roller electronic control program is written, so that the newly added pinch roller 28 and the original pre-finishing pinch roller 12 of the production line form a process design of double pinch rollers before sizing, so as to solve the problem of conveying products with large sizes exceeding the design limit in actual production, ensure the smooth passage of rolled pieces, reduce the accidents of steel piling, and improve the realization of continuous and stable production.

[0028] The design steps of the present invention are:

[0029] 1. Analysis of production problems of ultra-large specifications and selection of the location of the newly added pinch rollers;

[0030] 2. Added pinch roller system design, including: added pinch roller hole design and pinch roller gap setting;

[0031] 3. Speed ​​and interlocking electrical control of double pinch rollers.

[0032] This design is carried out in steps. First, the reasons for the formation of large-sized top steel are analyzed, and then the position and plan of the new pinch rollers are determined. Then the hole type of the new pinch rollers and the roller gap control are designed, and then the interlocking electrical control program of the new and original pinch rollers is edited. Finally, the double pinch roller production process of high-speed wire with ultra-limit large specifications is realized.

[0033] (1) Theoretical calculation and cause analysis of the formation of large-size top steel:

[0034] The bending of the pressure rod is mechanically analyzed using the Euler formula in material mechanics. The rolled piece at the 2# shear is regarded as a section of the pressure rod. If the rolled piece is subjected to a large thrust and becomes bent, it will rush out of the guide groove after the shear, causing a steel pile accident. The above phenomenon is analyzed using the Euler formula.

[0035] Critical force for the stability of the compression rod (Euler's formula)

[0036] Where: E——Young's modulus of the material;

[0037] i——moment of inertia (cross-sectional parameter);

[0038] μ——constraint coefficient;

[0039] L——rod length;

[0040] Analyzing the Euler formula, we can get:

[0041] ① The greater the Young's modulus E and moment of inertia i of the material, the greater the critical force and the more stable the compression rod;

[0042] ②The smaller the constraint coefficient μ, the shorter the length; the greater the critical force, the more stable the compression rod.

[0043] Since the rolled products coming out of the 12-stand rolling mill are Φ32.4mm round rolled products, the bending limit force of the φ32.4 steel bar in the 2# shear guide groove is calculated using the Euler formula as follows:

[0044] Table 1 Calculation table of bending limit force of rolled products

[0045]

[0046] If a steel bar is subjected to a force greater than the bending limit of the rolled piece, it will bend at this position. The closed part will be constrained by the outside, and the open part will rush out of the guide groove and become tangled, resulting in a steel pile accident.

[0047] (2) Analysis of the stress on the rolled piece after the No. 2 flying shear and determination of the position of the newly added pinch rollers

[0048] The 2# flying shear guide groove is located at the 2# flying shear behind the 12-stand rolling mill. The rolled piece comes out of the 12-stand rolling mill and is pushed by the rolling mill. It is sent to the sizing mill along the guide groove. In this process, the rolled piece is pushed by the rear of the rolling mill on the one hand, and is subjected to various resistances in the running channel on the other hand. (Of course, the rolled piece lies flat in the channel, and the constraint coefficient μ caused by the support force of the guide tube wall becomes smaller, making it difficult for the rolled piece to bend).

[0049] From the above, we can know that the thrust of the rolled piece from the 12th rolling mill to the sizing mill is the largest (because the combined force of friction resistance is the largest). Therefore, the pressure (thrust) of the rolled piece at this location is most likely to exceed the critical force F. cr That is, the rolled piece is most likely to bend and pile up at this point.

[0050] The resultant force ΣF on the rolled products at the exit of the 12 rolling mills at the 2# flying shear guide groove is:

[0051] ΣF=Fm+F j +Fa+Fc+Fy

[0052] Where: Fm - normal friction resistance of horizontal guide tube to rolled piece;

[0053] F j ——The resistance of cooling water, compressed air and other media to the rolled product;

[0054] Fa = ma - the acceleration force generated by the speed change of the rolled piece;

[0055] Fc——The axial force generated by the chamfer of the conduit inlet and the impact on the end of the rolled piece;

[0056] Fy - hard resistance caused by collision due to unexpected situations such as installation and processing of components in the channel.

[0057] After calculation, the empty position at the 2# flying shear behind the 12th rolling mill is the location with the greatest comprehensive resistance, which is also the accident point where steel piling frequently occurs. We look for equipment with the most suitable mechanical, power and electronic control conditions as the pinch roller. The 13th rolling mill is closest to this position and fully meets the requirements of all conditions. Therefore, the 13th rolling mill is determined as the new pinch roller.

[0058] 2. New pinch roller system design, including the hole design of the new pinch roller and the roller gap setting;

[0059] Using the original 13th roller as the new pinch roller, guide roller, etc. can save costs to the maximum extent; the hole design of the new pinch roller is as follows, according to the material shape of the 12th frame billet is a circle with a diameter of 32.4, in order to avoid scratches and indentations on the pinched rolled piece, the pinch hole adopts an open round bottom hole radius R of 16.5, the hole side wall adopts 35°, and the hole corner radius adopts r as a transition of 2 to avoid deformation and scratches of the rolled piece during work and damage to the surface.

[0060] The roll gap is designed to be adjustable, and the adjustment method of the roll gap of the rolling mill is used. Taking into account the bounce of the rolling mill and the deviation of the seasoning, when the roll gap is adjusted, the adjustment value is 0.5mm smaller than the rolled piece.

[0061] 3. Speed ​​and interlocking electrical control of double pinch rollers

[0062] Since the speed of the rolled piece is constantly changing during the actual production process, the speed of the newly added pinch roller must match the rolled piece, so the electrical control is designed to form an interlocking control with the speeds of the 12 frames in front of it; since the conventional design of high-speed wire rods originally has a design of pinch rollers before finishing rolling, the present invention relates to the electrical control problem of double pinch rollers.

[0063] In the control system of high-speed wire rod, the original control of the pinch rollers before finishing rolling includes the pinch opening and closing time, lifting speed, cascade and timing problems with other rolling mills and detection components; now the new pinch rollers after the 2# flying shear are added, the cascade and timing problems of the new pinch rollers and other equipment and detection components are added, and the association and control problems of the original pinch rollers and the new pinch rollers are also brought. In the present invention, it is set that the control timing and speed of the double pinch rollers are based on the NO.12 rolling mill. 10 seconds after the head of the rolled piece leaves the NO.12 rolling mill, the new pinch roller 28 performs the closing pinch action. 17 seconds after the head of the rolled piece leaves the NO.12 rolling mill, the pinch roller 12 before finishing rolling performs the closing pinching action; after the head of the rolled piece bites into the sizing unit 17, the pinch roller 12 before finishing rolling performs the opening action, and the newly added pinch roller 28 ensures the pinching state; the set speed of the newly added pinch roller 28 is 5-7% ahead of the NO.12 rolling mill, and the speed change of the pinch roller 12 before finishing rolling is 8-13% ahead of the newly added pinch roller. In this way, the rolled piece can form a micro-tension between the two pinch rollers to avoid steel piling accidents; the continuous rolling speed matching relationship between the double pinch rollers can be adjusted by changing the advance coefficient.

[0064] The above embodiments are only used to illustrate rather than limit the technical solutions of the present invention. Although the present invention is described in detail with reference to the above embodiments, those skilled in the art should understand that the present invention can still be modified or replaced by equivalents. Any modification or partial replacement that does not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A method for producing a large-size pinch roller for high-speed wire rods exceeding the design limit, characterized in that The following steps are involved: Analysis of production problems of ultra-large specifications and selection of the location of additional pinch rolls. Pinch rolls were added to the NO.13 rolling mill on the production line. Add pinch rolls, use the existing rolling mill as the new pinch rolls, design the pinch roll hole type on the rolls according to the material type, and adjust the pinch roll gap through the rolling mill adjustment mechanism; The speed and interlocking electrical control of the double pinch rollers. During the production process of extremely large-size products, the speed and timing of the newly added pinch rollers and the original pinch rollers before finishing rolling of the production line are electrically interlocked to form double pinch rollers before sizing.

2. The method for producing a high-speed wire rod large-size pinch roller exceeding the design limit according to claim 1, characterized in that: In the step (1), the bending of the pressure rod is mechanically analyzed using the Euler formula in material mechanics. The rolled piece located at the 2# flying shear is regarded as a section of the pressure rod. If the rolled piece is subjected to a large thrust and becomes bent, it will rush out of the guide groove after the shearing, causing a steel pile accident here. The position of the newly added pinch roller is determined to be the position of the NO. 13 rolling mill after the 2# flying shear.

3. The method for producing a large-size pinch roller for high-speed wire rods exceeding the design limit according to claim 1, characterized in that: In the step (2), according to the NO.12 rack material type Φ32.4mm circle, the pinch hole type adopts an open groove top arc with a radius R of 16.5mm, the hole side wall adopts 35°, and the hole corner radius adopts r as a transition of 2mm; the pinch roller gap is designed as an adjustable structure, and the adjustment method of the rolling mill gap is used. Considering the bounce of the rolling mill and the deviation of the material, when the roll gap is set, the adjustment value is 0.5mm smaller than the rolled piece.

4. The method for producing a high-speed wire rod large-size pinch roller exceeding the design limit according to claim 1, characterized in that: In the step (3), the control sequence and speed of the double pinch rolls are based on the NO.12 mill. 10 seconds after the head of the rolled piece exits the NO.12 mill, the newly added pinch roll performs a pinch closing action; 17 seconds after the head of the rolled piece exits the NO.12 mill, the pinch roll before finishing rolling performs a pinch closing action; after the head of the rolled piece bites into the sizing mill, the pinch roll before finishing rolling performs an opening action, and the newly added pinch roll ensures the pinching state; the set speed of the newly added pinch roll is 5-7% ahead of the NO.12 mill, and the speed of the pinch roll before finishing rolling is changed to 8-13% ahead of the new pinch roll, so that the rolled piece forms a micro-tension between the two pinch rolls to avoid steel piling accidents; the continuous rolling speed matching relationship between the double pinch rolls is adjusted by changing the advance coefficient.

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