Hydraulic circuit of roller edge heating device and control method of hydraulic circuit

Abstract

The invention discloses a hydraulic circuit of a roller edge heating device and a control method thereof, the hydraulic circuit comprises an oil cylinder connected with a heating head, the hydraulic circuit of the oil cylinder is provided with an electromagnetic directional valve used for controlling the oil cylinder to advance and retreat, and a P port pressure reducing valve is arranged on a P port of the hydraulic circuit of the oil cylinder. A port A pressure reducing valve is arranged on a port P of a hydraulic circuit of the oil cylinder. A pressure sensor A is arranged on the hydraulic loop of the oil cylinder and close to the pressure reducing valve A, and a pressure sensor B is arranged on the hydraulic loop of the oil cylinder and close to the oil cylinder. And a proportional throttle valve is arranged on a hydraulic loop of the oil cylinder close to the pressure sensor A. According to the structure and the method, the design thought is changed, the function of automatically calibrating the zero position of the gap between the electromagnetic heating head and the roller is achieved on a hydraulic loop, operation is more convenient, positioning is accurate, the roller does not need to be contacted every time after calibration, and the using process is safe and reliable.

Description

Technical Field

[0001] The present invention relates to the technical field of nonferrous metal processing, in particular to a hydraulic circuit of a roller edge heating device and a control method thereof. Background Art

[0002] The cold rolling mill roll edge heating device is one of the important equipment of the aluminum plate and strip cold rolling mill. With the improvement of the rolling requirements of the aluminum plate and strip cold rolling mill, during the aluminum plate and strip rolling process, it is required that the working rolls on both sides can be heated at the edge of the strip to change the convexity of the roll edge, so that the strip edge is not easy to form a tight edge and cause strip breakage, thereby improving product quality and unit efficiency.

[0003] To meet the above requirements, the traditional approach is to use hot oil spraying on the edge of the roll. The disadvantage of this approach is that it heats up slowly and cannot meet the needs of adjustment at any time. In addition, the investment cost is high, the oil temperature requirement is relatively high, and it is difficult to implement.

[0004] Electromagnetic heating is becoming increasingly popular. Its basic principle is to apply real-time heating by placing an electromagnetic heating head close to the desired area of ​​the roll. This approach offers rapid heating and precise positioning. However, two commonly used solutions have drawbacks: 1. The hydraulic cylinder plus position displacement sensor proportional advance approach: This approach fails to consider how to conveniently calibrate the zero contact position between the heating head and the mill roll surface. Consequently, each zero calibration requires workers to enter the mill and, in the extremely confined space, use a feeler gauge to slowly measure the gap between the electromagnetic heating head and the roll. This process is cumbersome and inaccurate, and can sometimes damage the equipment due to improper operation. 2. The pneumatic cylinder advance contact approach plus hydraulic cylinder retraction fixed distance approach: This approach requires the cylinder to gently advance the induction heating head into contact with the roll each time. Because hydraulic cylinder movement is less smooth than hydraulic movement, this approach often results in jamming or false alarms. Furthermore, because the hydraulic cylinder retraction distance is approximately 3 mm, the motion signal recognition may be inaccurate or false alarms may occur. Furthermore, the fixed gap between the heating head and the roll is not conducive to flexible adjustment and finding the optimal gap, resulting in drawbacks. To this end, we propose a hydraulic circuit for a roll edge heating device and a control method thereof. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the existing defects and provide a hydraulic circuit for a roller edge heating device and a control method thereof. Compared with the traditional hot oil heating solution, electromagnetic heating itself has the advantages of fast heating, accurate positioning and low energy consumption. At the same time, it optimizes the positioning mechanism of the electromagnetic heating head, solves the core pain points of the existing electromagnetic heating solution (difficult calibration, ineffective gap adjustment, and poor stability), so that the advantages of electromagnetic heating can be fully utilized, which can effectively solve the problems in the background technology.

[0006] To achieve the above object, the present application provides the following technical scheme: a hydraulic circuit of a roll edge heating device, comprising a cylinder connected with a heating head, an electromagnetic reversing valve for controlling the forward and backward movement of the cylinder is arranged on the hydraulic circuit of the cylinder, a P port pressure reducing valve is arranged on the P port of the hydraulic circuit of the cylinder, and an A port pressure reducing valve is arranged on the P port of the hydraulic circuit of the cylinder.

[0007] As a preferred technical scheme of the present application, a pressure sensor A is arranged on the hydraulic circuit of the cylinder close to the A port pressure reducing valve, and a pressure sensor B is arranged on the hydraulic circuit of the cylinder close to the cylinder.

[0008] As a preferred technical scheme of the present application, a proportional throttle valve is arranged on the hydraulic circuit of the cylinder close to the pressure sensor A.

[0009] As a preferred technical scheme of the present application, a cylinder displacement sensor is arranged on the cylinder.

[0010] As a preferred technical scheme of the present application, the area ratio of the plug cavity and the rod cavity of the cylinder is 2:1.

[0011] The present application also provides a control method of the hydraulic circuit of the roll edge heating device, which adopts the above-mentioned hydraulic circuit of the roll edge heating device and comprises the following steps: Differential forward movement: when the heating head needs to move forward, the electromagnetic reversing valve b end electromagnet is electrified, at this time, the cylinder moves forward differentially, the area ratio of the plug cavity and the rod cavity of the cylinder is 2:1, so that the actual output of the cylinder is only equivalent to the pressure work of 1 MPa of the plug cavity; Roll contact: the cylinder displacement sensor is observed, when the reading of the cylinder displacement sensor no longer changes, it indicates that the heating head has contacted with the roll, at this time, the value of the cylinder displacement sensor indicates that the gap between the heating head and the roll is 0 mm, because only the action of 1 MPa of the plug cavity pressure of the cylinder, the heating head will not be damaged, and the difference of the two pressure reducing valves can be set according to the actual situation to ensure the safety of the heating head; Dynamic gap adjustment: the electromagnetic reversing valve a end electromagnet is electrified, at this time, the cylinder moves backward, the gap between the heating head and the roll is controlled within 3-5 mm according to the change of the cylinder displacement sensor, at this time, the zero and position adjustment work is completed; Heating head work: after the zero and position adjustment work is completed, the electromagnetic heating head approaches the part of the roll that needs to be heated, and starts to heat it in real time.

[0012] As a preferred technical scheme of the present application, the following step is further included: pressure monitoring: during the dynamic gap adjustment process, the pressure sensor A and the pressure sensor B detect the actual pressure of the pressure reducing valve, to ensure that the heating head will not be damaged after contacting the roll.

[0013] As a preferred technical scheme of the present application, the following steps are further included: emergency quick retraction: in order to control the speed of the cylinder action and make the adjustment more accurate, the opening of the proportional throttle valve is controlled to be small, when the rolling mill appears an emergency such as fire, the speed of the cylinder retraction needs to be fast, at this time, the opening of the proportional throttle valve is fully opened, so that the quick retraction of the heating head is realized.

[0014] As a preferred technical scheme of the present application, the pressure of the P port pressure reducing valve is adjusted to 8 MPa, and the pressure of the A port pressure reducing valve is adjusted to 5 MPa.

[0015] Compared with the prior art, the present application has the following beneficial effects: 1. The design idea is changed, the function of automatically calibrating the zero position of the gap between the electromagnetic heating head and the roll is realized from the hydraulic circuit, the operation is more convenient, the positioning is accurate, after calibration, there is no need to contact the roll every time, and the use process is safe and reliable.

[0016] 2. Through the differential forward mode (only 1 MPa low pressure) combined with real-time monitoring of the cylinder displacement sensor, the contact zero position (gap = 0 mm) of the heating head and the roll can be automatically and accurately identified. This process does not need manual intervention in the narrow space of the rolling mill for high-risk manual measurement (such as plug gauge operation), eliminates the manual calibration error, operation risk and equipment damage hidden danger, greatly improves the calibration efficiency and accuracy.

[0017] 3. After accurately obtaining the zero position reference, the heating head and the roll gap can be dynamically and continuously controlled in the best range (3-5 mm) by using the stable retraction of the hydraulic system and according to the feedback of the displacement sensor, which overcomes the gap rigidity problem caused by the traditional fixed retraction distance (3 mm), significantly improves the debugging flexibility and heating effect controllability, and more easily finds and maintains the best working gap. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a structure schematic view of the hydraulic circuit of the heating device of the present application; Figure 2 It is a flowchart of the control method of the present application.

[0019] In the figure: 1 P port pressure reducing valve, 2 electromagnetic reversing valve, 3 A port pressure reducing valve, 4 pressure sensor A, 5 proportional throttle valve, 6 pressure sensor B, 7 cylinder, 8 cylinder displacement sensor. DETAILED DESCRIPTION

[0020] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0021] Please refer to Figure 1 The present application provides a technical solution: a hydraulic circuit of a roll edge heating device, comprising a cylinder 7 connected with a heating head, an electromagnetic reversing valve 2 for controlling the forward and backward movement of the cylinder 7 is arranged on the hydraulic circuit of the cylinder 7, the hydraulic control circuit adopts an R-type middle electromagnetic reversing valve 2 for forward and backward control, a P-port pressure reducing valve 1 is arranged on the P-port of the hydraulic circuit of the cylinder 7, and the pressure is adjusted to 8 MPa; an A-port pressure reducing valve 3 is arranged on the P-port of the hydraulic circuit of the cylinder 7, and the pressure is adjusted to 5 MPa. The arrangement of the P-port pressure reducing valve and the A-port pressure reducing valve accurately controls the system pressure, ensures the action requirement, and provides overload protection for the key components and the heating head.

[0022] The present application changes the design idea, realizes the function of automatically calibrating the gap between the electromagnetic heating head and the roll from the hydraulic circuit, is more convenient to operate, and is accurate in positioning. After calibration, the roll does not need to be contacted every time, and the use process is safe and reliable.

[0023] In the preferred technical solution, a pressure sensor A4 is arranged on the hydraulic circuit of the cylinder 7 close to the A-port pressure reducing valve 3, a pressure sensor B6 is arranged on the hydraulic circuit of the cylinder 7 close to the cylinder 7, the pressure sensor A4 and the pressure sensor B6 detect the actual pressure of the A-port pressure reducing valve 3 and the P-port pressure reducing valve 1 respectively, and ensure that the heating head will not be damaged after contacting the roll.

[0024] In the preferred technical solution, a proportional throttle valve 5 is arranged on the hydraulic circuit of the cylinder 7 close to the pressure sensor A4. In order to control the action speed of the cylinder 7, the adjustment accuracy is higher. At this time, the opening of the proportional throttle valve 5 is controlled to be very small. When the rolling mill appears an emergency such as fire, the speed of the cylinder 7 needs to be very fast. At this time, the opening of the proportional throttle valve 5 is fully opened, so that the heating head can be quickly retreated.

[0025] In the preferred technical solution, a cylinder displacement sensor 8 is arranged on the cylinder 7. The cylinder displacement sensor 8 is used to detect the gap between the heating head and the roll. The gap can be controlled by observing the value of the cylinder displacement sensor 8 or by an external controller such as a PLC controller to automatically control the opening and closing of the electromagnetic reversing valve 2 according to the value of the cylinder displacement sensor 8.

[0026] The pressure reducing valve, electromagnetic reversing valve, pressure sensor, proportional throttle valve and the like used in the present application are all electronic components commonly used in the prior art, and their specific structure, working principle, control mode and circuit connection are all known technology, which will not be described in detail here.

[0027] Please refer to Figure 2 The present application also provides a control method of the hydraulic circuit of the roll edge heating device, which adopts the hydraulic circuit of the roll edge heating device and comprises the following steps: Differential advance: when the heating head needs to advance, the electromagnet at the end of the electromagnetic reversing valve 2b is electrified, at this time the oil cylinder 7 differentially advances, and the area ratio of the plug cavity and the rod cavity of the oil cylinder 7 is 2:1, so that the actual output of the oil cylinder 7 is only equivalent to the pressure work of 1 MPa of the plug cavity; Roll contact: observe the oil cylinder displacement sensor 8, when the reading of the oil cylinder displacement sensor 8 no longer changes, it means that the heating head has contacted the roll, at this time the value of the oil cylinder displacement sensor 8 indicates that the gap between the heating head and the roll is 0 mm, because only the action of 1 MPa of the plug cavity pressure of the oil cylinder, the heating head will not be damaged, and the difference between the two pressure reducing valves can be set according to the actual situation to ensure the safety of the heating head; Dynamic gap adjustment: the electromagnet at the end of the electromagnetic reversing valve 2a is electrified, at this time the oil cylinder 7 retreats, and the gap between the heating head and the roll is controlled within 3-5 mm according to the change of the oil cylinder displacement sensor 8, at this time the zero and position adjustment work is completed; Heating head work: after the zero and position adjustment work is completed, the electromagnetic heating head approaches the part of the roll that needs to be heated, and starts to heat it in real time.

[0028] Pressure monitoring: during the dynamic gap adjustment process, the pressure sensor A4 and the pressure sensor B6 detect the actual pressure of the pressure reducing valve to ensure that the heating head will not be damaged after contacting the roll.

[0029] Emergency quick retreat: in order to control the action speed of the oil cylinder 7 and make the adjustment accuracy higher, the opening of the proportional throttle valve 5 is controlled to be very small at this time, when the rolling mill appears fire and other emergency situations, the retreat speed of the oil cylinder 7 needs to be very fast, at this time the opening of the proportional throttle valve 5 is fully opened, so that the quick retreat of the heating head can be realized.

[0030] The method uses a hydraulic system (oil cylinder) to drive throughout the process, and the action is stable and reliable, completely solving the problems of action blockage and signal false reporting that easily occur in the cylinder scheme, and the system runs more stably and has a low failure rate.

[0031] The undisclosed parts in the present application are all prior arts, and their specific structures, materials and working principles are not described in detail. Although the embodiments of the present application have been shown and described, it is understood to those ordinary skilled in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A hydraulic circuit for a roller edge heating device, comprising an oil cylinder (7) connected to a heating head, characterized in that: The hydraulic circuit of the oil cylinder (7) is provided with an electromagnetic reversing valve (2) for controlling the forward and backward movement of the oil cylinder (7), the P port of the hydraulic circuit of the oil cylinder (7) is provided with a P port pressure reducing valve (1), and the P port of the hydraulic circuit of the oil cylinder (7) is provided with an A port pressure reducing valve (3).

2. The hydraulic circuit of a roller edge heating device according to claim 1, characterized in that: A pressure sensor A (4) is provided on the hydraulic circuit of the oil cylinder (7) near the A-port pressure reducing valve (3), and a pressure sensor B (6) is provided on the hydraulic circuit of the oil cylinder (7) near the oil cylinder (7).

3. The hydraulic circuit of the roller edge heating device according to claim 2, characterized in that: A proportional throttle valve (5) is provided on the hydraulic circuit of the oil cylinder (7) near the pressure sensor A (4).

4. The hydraulic circuit of a roller edge heating device according to claim 1, characterized in that: The oil cylinder (7) is provided with an oil cylinder displacement sensor (8).

5. A hydraulic circuit for a roll edge heating device according to any one of claims 1 to 4, characterized in that: The area ratio of the plug cavity and the rod cavity of the oil cylinder (7) is 2:

1.

6. A method for controlling a hydraulic circuit of a roll edge heating device, using the aforementioned hydraulic circuit of a roll edge heating device, characterized in that: The following steps are involved: Differential advance: When the heating head needs to advance, the electromagnet at the end b of the electromagnetic reversing valve (2) is energized, and the oil cylinder (7) then advances differentially. The area ratio of the plug cavity and the rod cavity of the oil cylinder (7) is 2:1, so the actual output of the oil cylinder (7) is only equivalent to the pressure of 1MPa in the plug cavity; Heating head and roller contact: Observe the oil cylinder displacement sensor (8). When the reading of the oil cylinder displacement sensor (8) no longer changes, it means that the heating head has contacted the roller. At this time, the value of the oil cylinder displacement sensor (8) indicates that the gap between the heating head and the roller is 0mm. Because there is only 1MPa of oil cylinder plug pressure, the heating head will not be crushed. The difference between the two pressure reducing valves can also be set according to the actual situation on site to ensure the safety of the heating head. Dynamic gap adjustment: The electromagnet at end a of the electromagnetic reversing valve (2) is energized, and the oil cylinder (7) moves backward. The gap between the heating head and the roller is controlled within 3-5 mm according to the change of the oil cylinder displacement sensor (8). At this time, the zero and position adjustment work is completed; Heating head works: After the zeroing and position adjustment work is completed, the electromagnetic heating head is close to the part of the roller that needs to be heated and starts to heat it in real time.

7. A method for controlling a hydraulic circuit of a roller edge heating device according to claim 6, characterized in that: The following steps are also included: Pressure monitoring: During the dynamic gap adjustment process, pressure sensor A (4) and pressure sensor B (6) detect the actual pressure of the pressure reducing valve to ensure that the heating head will not be damaged after contacting the roller.

8. A method for controlling a hydraulic circuit of a roll edge heating device according to claim 6 or 7, characterized in that: The following steps are also included: Rapid retraction in emergency situations: In order to control the speed of the oil cylinder (7) and make the adjustment more precise, the opening of the proportional throttle valve (5) is controlled to be very small. When an emergency such as a fire occurs in the rolling mill, the speed of the oil cylinder (7) needs to be very fast. At this time, the opening of the proportional throttle valve (5) is fully opened to achieve rapid retraction of the heating head.

9. The method for controlling the hydraulic circuit of a roller edge heating device according to claim 8, characterized in that: The pressure of the P-port pressure reducing valve (1) is adjusted to 8 MPa, and the pressure of the A-port pressure reducing valve (3) is adjusted to 5 MPa.

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