Control method for prolonging service life of mandrel of coiling machine

Abstract

The invention relates to a control method for prolonging the service life of a mandrel of a coiling machine, and belongs to the technical field of steel rolling equipment control methods. According to the technical scheme, the method comprises the steps that the number of pairs of wrapper roller pressure adjusting servo systems is adjusted, according to the strip steel tracking position, the wrapper roller short stroke function is developed by pre-judging and reducing the servo output quantity of the wrapper roller in the servo downward direction in advance, and wrapper roller control is carried out; when the steel coil just leaves the mandrel of the coiling machine, mandrel cooling water is opened, and a path of cooling water is added behind a No.1 wrapper roller; a dry oil lubrication model is optimized, and a dry oil pipeline is thoroughly broken through. The method has the beneficial effects that the impact of strip steel and the wrapper roller on the mandrel is reduced by optimizing a wrapper roller servo control strategy, increasing a wrapper roller head short stroke function and the like, the cooling effect of the mandrel is improved by innovating a mandrel cooling water process control mode, the mandrel lubrication in-place rate and the effective rate are improved by innovating a dry oil pumping control method, and the production cost is reduced. Therefore, the service life of the mandrel is prolonged.

Description

Technical Field

[0001] The invention relates to a control method for extending the service life of a coiler mandrel, and belongs to the technical field of steel rolling equipment control methods. Background Art

[0002] The coiler in the hot-rolled strip production line is a key quality equipment in the production line. It has a key impact on the successful establishment of tension and coil shape control of the coiler. It is expensive and takes a long time to replace. It is the key maintenance equipment of the hot-rolled production line. To reduce the cost and improve the quality of the production line, it is necessary to extend the life of the coiler mandrel and ensure its good condition. The main factors affecting the life of the mandrel are the wear of the mandrel caused by the impact of external force on the mandrel, the untimely and insufficient cooling of the mandrel, and the failure of lubrication. The external force impact is mainly the impact of the strip and the auxiliary roller on the mandrel from the start of stepping control when the strip enters the coiler auxiliary roller to the opening of the auxiliary roller after coiling. Due to the complex process of coiling the head of the strip on the mandrel, improper adjustment of the auxiliary roller servo will cause the mandrel to be subjected to a huge impact, sometimes up to 1300kN, which will cause great damage to the mandrel.

[0003] The problem of untimely cooling of the mandrel: The mandrel of the hot rolling production line is in contact with the high-temperature strip steel of more than 700 degrees for a long time during the coiling process, and the temperature rise of the body is very high. After the steel coil is unloaded, a short water spray cooling process will be carried out when the auxiliary rolls are closed. After the auxiliary rolls are cooled by the cooling water of the auxiliary rolls, they will flow to the mandrel to cool down until the next roll of steel enters the coiler. In the environment of efficient production of the production line, the cooling time is insufficient, resulting in the inability to fully cool the mandrel, and it has been in a high-temperature working state. The rigidity of the mandrel fan plate will change, the internal organizational structure will change, and the surface will easily produce pits or cracks, resulting in the end of the life of the mandrel. The long-term high temperature of the mandrel will also bring another very unfavorable problem, that is, the lubricating oil inside the mandrel will be denatured or even hardened at high temperature, causing the internal lubricating oil pipe to be blocked. Once the internal lubricating oil pipe is blocked, it will be very difficult to clear it, and it will also cause the mandrel to be taken off the machine for maintenance.

[0004] Lubrication failure problem: Since the mandrel always runs at high temperature, its internal dry oil lubrication mode does not meet the requirements of the environment. The general mode of the dry oil lubrication system is to pressurize and lubricate the two dry oil pipelines every 10 minutes. When the pressure of the first pipeline reaches 130bar, switch to the second pipeline for oiling. Similarly, when the pressure reaches 130bar, stop oiling and wait for 10 minutes before repeating the above cycle. Since only a small amount of dry oil can be pumped into the pipeline each time, the dry oil in the mandrel dry oil pipeline is updated for too long. Under the action of high temperature, the dry oil denatures and even hardens, causing the mandrel to be taken offline for maintenance.

[0005] All of the above problems will have a relatively adverse impact on the service life of the mandrel, and innovative methods are urgently needed to solve them. Summary of the invention

[0006] The purpose of the present invention is to provide a control method for extending the life of the coiler mandrel, by optimizing the servo control strategy of the auxiliary winding roller, adding the short stroke function of the auxiliary winding roller head, etc., to reduce the impact of the strip steel and the auxiliary winding roller on the mandrel, by innovating the mandrel cooling water process control method to improve the cooling effect of the mandrel, by innovating the dry oil oiling control method, to improve the lubrication rate and efficiency of the mandrel, thereby increasing the life of the mandrel, and effectively solving the above-mentioned problems existing in the background technology.

[0007] The technical solution of the present invention is: a control method for extending the life of a coiling machine mandrel, comprising the following steps:

[0008] (1) Control of the auxiliary roll: adjust the logarithm of the servo system of the auxiliary roll pressure to solve the resonance problem of the auxiliary roll during the steel feeding process of the coiler; according to the tracking position of the strip, reduce the servo output of the auxiliary roll servo in the downward direction in advance through prediction to reduce the impact force of the auxiliary roll on the mandrel; develop the short stroke function of the auxiliary roll to determine the swing-in time of the auxiliary roll. Before the head of the strip arrives at the coiler, the auxiliary roll waits at the position of the set value + short stroke. When the head of the strip arrives, it swings to the set position to avoid collision with the auxiliary roll when waiting for the steel;

[0009] (2) Mandrel cooling water control: turn on the mandrel cooling water when the steel coil just leaves the coiler mandrel, and install an additional cooling water line after the No. 1 auxiliary coiling roller;

[0010] (3) Dry oil lubrication system control, optimize the dry oil lubrication model, and completely open up the dry oil pipeline.

[0011] In the step (1), the logarithm of the servo system is adjusted in the pressure of the winding roller, a delay link is added in the feedback calculation of the pressure of the winding roller, and the delay time parameter is adjusted, thereby changing the phase of the fluctuation cycle and avoiding the coupling between the winding roller body and the servo system cycle.

[0012] In the step (1), when it is determined that the strip head rotates downward according to the strip tracking position, the servo output of the auxiliary winding roller in the downward direction is reduced in advance to reduce the impact force of the auxiliary winding roller on the core shaft.

[0013] In the step (1), the calculation formula for the timing of the auxiliary winding roller swinging in is:

[0014] T=l / vt

[0015] Where, l: the distance between the cold metal detector CMD and the auxiliary roll;

[0016] V: speed of the strip passing through;

[0017] T: margin time.

[0018] In the step (2), a coil unloading trolley is provided under the coiler to unload the steel coil from the coiler by transverse movement; a displacement sensor is installed in the transverse movement hydraulic cylinder of the coil unloading trolley, and when it is calculated that the coil unloading trolley has left the coiler mandrel, the mandrel cooling water is turned on in advance and the mandrel is rotated for cooling.

[0019] In the step (3), the original single cycle of route A followed by route B, followed by a 5-minute wait, is changed to multiple cycles of route A followed by route B for 6 minutes, followed by an idle period of 4 minutes.

[0020] The coiler is composed of a core shaft and three auxiliary winding rollers surrounding the core shaft, and the opening and closing of the auxiliary winding rollers toward the core shaft is controlled by a hydraulic servo system.

[0021] The beneficial effects of the present invention are as follows: by optimizing the servo control strategy of the auxiliary winding roller, increasing the short-stroke function of the auxiliary winding roller head, etc., the impact of the strip steel and the auxiliary winding roller on the mandrel is reduced; by innovating the mandrel cooling water process control method to improve the cooling effect of the mandrel; by innovating the dry oil oiling control method, the mandrel lubrication rate and efficiency are improved, thereby increasing the life of the mandrel. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the system structure of the present invention. DETAILED DESCRIPTION

[0023] 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.

[0024] A control method for extending the life of a coiling machine mandrel comprises the following steps:

[0025] (1) Control of the auxiliary roll: adjust the logarithm of the servo system of the auxiliary roll pressure to solve the resonance problem of the auxiliary roll during the steel feeding process of the coiler; according to the tracking position of the strip, reduce the servo output of the auxiliary roll servo in the downward direction in advance through prediction to reduce the impact force of the auxiliary roll on the mandrel; develop the short stroke function of the auxiliary roll to determine the swing-in time of the auxiliary roll. Before the head of the strip arrives at the coiler, the auxiliary roll waits at the position of the set value + short stroke. When the head of the strip arrives, it swings to the set position to avoid collision with the auxiliary roll when waiting for the steel;

[0026] (2) Mandrel cooling water control: turn on the mandrel cooling water when the steel coil just leaves the coiler mandrel, and install an additional cooling water line after the No. 1 auxiliary coiling roller;

[0027] (3) Dry oil lubrication system control, optimize the dry oil lubrication model, and completely open up the dry oil pipeline.

[0028] In the step (1), the logarithm of the servo system is adjusted in the pressure of the winding roller, a delay link is added in the feedback calculation of the pressure of the winding roller, and the delay time parameter is adjusted, thereby changing the phase of the fluctuation cycle and avoiding the coupling between the winding roller body and the servo system cycle.

[0029] In the step (1), when it is determined that the strip head rotates downward according to the strip tracking position, the servo output of the auxiliary winding roller in the downward direction is reduced in advance to reduce the impact force of the auxiliary winding roller on the core shaft.

[0030] In the step (1), the calculation formula for the timing of the auxiliary winding roller swinging in is:

[0031] T=l / vt

[0032] Where, l: the distance between the cold metal detector CMD and the auxiliary roll;

[0033] V: speed of the strip passing through;

[0034] T: margin time.

[0035] In the step (2), a coil unloading trolley is provided under the coiler to unload the steel coil from the coiler by transverse movement; a displacement sensor is installed in the transverse movement hydraulic cylinder of the coil unloading trolley, and when it is calculated that the coil unloading trolley has left the coiler mandrel, the mandrel cooling water is turned on in advance and the mandrel is rotated for cooling.

[0036] In the step (3), the original single cycle of route A followed by route B, followed by a 5-minute wait, is changed to multiple cycles of route A followed by route B for 6 minutes, followed by an idle period of 4 minutes.

[0037] The coiler is composed of a core shaft and three auxiliary winding rollers surrounding the core shaft, and the opening and closing of the auxiliary winding rollers toward the core shaft is controlled by a hydraulic servo system.

[0038] In practical applications, the factors that affect the life of the spindle are mainly external force impact, cooling and dry oil lubrication. By adjusting the servo system parameters and reducing external forces, a series of methods are used to improve the operating conditions of the spindle and extend the life of the spindle. The control methods mainly include:

[0039] Control method of auxiliary winding roller: By adding a delay link in the pressure feedback calculation of the auxiliary winding roller and adjusting the delay time parameters, the phase of the fluctuation cycle can be changed, the resonance problem in the step control process of the auxiliary winding roller when the coiler is feeding steel can be solved, and the coupling between the auxiliary winding roller body and the servo system cycle can be avoided. And according to the strip tracking position, when it is judged that the strip head rotates to the bottom, the servo output of the auxiliary winding roller servo in the downward direction is reduced in advance to reduce the impact force of the auxiliary winding roller on the mandrel; by developing the short stroke function of the auxiliary winding roller, the auxiliary winding roller waits at the position of the set value + short stroke before the strip head reaches the coiler, and when the strip head arrives, it swings to the set position, which can solve the problem of the core shaft colliding with the auxiliary winding roller when waiting for steel after the fan plate loosens in the middle and late stages of its life, accelerating the deterioration. Calculation formula for the timing of the auxiliary winding roller swinging in:

[0040] T=l / vt

[0041] Where, l: the distance between the cold metal detector CMD and the auxiliary roll,

[0042] V: Speed ​​of the strip passing through,

[0043] T: margin time.

[0044] Mandrel cooling water control: Install a displacement sensor in the hydraulic cylinder of the unloading trolley to calculate that the unloading trolley has left the mandrel of the coiler, open the mandrel cooling water in advance, and rotate the mandrel to cool it. At this time, the auxiliary winding roller is not closed, which can quickly cool the mandrel. And install a cooling water line after the No. 1 auxiliary winding roller to cool the mandrel after the mandrel is closed, avoid lubrication failure after the lubricating oil dries up, and restore its material strength to avoid breakage.

[0045] Dry oil lubrication system control: The dry oil lubrication model is optimized, from the original single cycle of route A then route B, and then waiting for 5 minutes, to multiple cycles of route A then route B for 6 minutes, and then idle for 4 minutes. This can completely open the dry oil pipeline at one time, and avoid the dry oil failing to open the dry oil pipeline in a single cycle after an interval of idle time, and the dry oil hardening due to long-term heat, which will eventually lead to the failure of spindle lubrication and the end of its service life.

[0046] The present invention solves the problem of the resonance of the auxiliary winding roller, avoids the coupling between the auxiliary winding roller body and the servo system cycle, and reduces pressure fluctuations; according to the strip tracking position, the servo output of the auxiliary winding roller servo in the downward direction is reduced in stages to reduce the impact force of the auxiliary winding roller on the mandrel; optimizes the material tracking system to ensure the accurate position of the auxiliary winding roller during step control; develops the short stroke function of the auxiliary winding roller to solve the problem of the mandrel colliding with the auxiliary winding roller after aging and accelerating deterioration; eliminates the integral cumulative error of the PI controller to make the servo setting more clearly purposeful. Increase the servo limit value in the opening direction of the auxiliary winding roller, enhance the movement speed of the auxiliary winding roller, and increase the set arrival rate. Optimize the cooling water timing of the mandrel and the auxiliary winding roller, and make the mandrel rotate to cool and cool quickly to avoid lubrication failure after the lubricating oil dries up, and restore its material strength to avoid breakage. Develop variable mandrel expansion force technology to enhance the mandrel expansion capacity.

[0047] The above description is only a preferred implementation example of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A control method for extending the life of a coiling machine mandrel, characterized in that The following steps are involved: (1) Control of the auxiliary roll: adjust the logarithm of the servo system in the auxiliary roll pressure to solve the resonance problem of the auxiliary roll during the steel feeding process of the coiler; according to the strip tracking position, reduce the servo output of the auxiliary roll servo in the downward direction in advance through prediction to reduce the impact force of the auxiliary roll on the mandrel; Develop the short-stroke function of the auxiliary winding roller to determine the swing-in timing of the auxiliary winding roller. Before the head of the strip reaches the coiler, the auxiliary winding roller waits at the position of the set value + short stroke. When the head of the strip arrives, it swings to the set position to avoid collision with the auxiliary winding roller when waiting for steel. (2) Mandrel cooling water control: turn on the mandrel cooling water when the steel coil just leaves the coiler mandrel, and install an additional cooling water line after the No. 1 auxiliary coiling roller; (3) Control the dry oil lubrication system, optimize the dry oil lubrication model, and completely open up the dry oil pipeline.

2. A control method for extending the life of a coiling machine mandrel according to claim 1, characterized in that: In the step (1), the logarithm of the servo system is adjusted in the pressure of the winding roller, a delay link is added in the feedback calculation of the pressure of the winding roller, and the delay time parameter is adjusted, thereby changing the phase of the fluctuation cycle and avoiding the coupling between the winding roller body and the servo system cycle.

3. A control method for extending the life of a coiling machine mandrel according to claim 1, characterized in that: In the step (1), when it is determined that the strip head rotates downward according to the strip tracking position, the servo output of the auxiliary winding roller in the downward direction is reduced in advance to reduce the impact force of the auxiliary winding roller on the core shaft.

4. A control method for extending the life of a coiling machine mandrel according to claim 1, characterized in that: In the step (1), the calculation formula for the timing of the auxiliary winding roller swinging in is: ； Where, l: the distance between the cold metal detector CMD and the auxiliary roll; V: speed of the strip passing through; T: margin time.

5. A control method for extending the life of a coiling machine mandrel according to claim 1, characterized in that: In the step (2), a coil unloading trolley is provided below the coiler to unload the steel coil from the coiler by means of transverse movement; a displacement sensor is installed in the transverse movement hydraulic cylinder of the coil unloading trolley, and when it is calculated that the coil unloading trolley has left the coiler mandrel, the mandrel cooling water is turned on in advance and the mandrel is rotated for cooling.

6. A control method for extending the life of a coiler mandrel according to claim 1, characterized in that: In the step (3), the original single cycle of route A followed by route B, followed by a 5-minute wait, is changed to multiple cycles of route A followed by route B for 6 minutes, followed by an idle period of 4 minutes.

7. A control method for extending the life of a coiling machine mandrel according to claim 1, characterized in that: The coiler is composed of a core shaft and three auxiliary winding rollers surrounding the core shaft, and the opening and closing of the auxiliary winding rollers toward the core shaft is controlled by a hydraulic servo system.

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