Multi-point roll bending hydraulic control system and control method for plate straightening machine

Abstract

The invention discloses a multi-point roll bending hydraulic control system and method for a plate straightening machine, the multi-point roll bending hydraulic control system for the plate straightening machine comprises a plurality of servo valve groups, a plurality of roll bending cylinders and a back pressure valve group, the plurality of servo valve groups respectively correspond to the plurality of roll bending cylinders, the servo valve groups are connected with rodless cavities of the roll bending cylinders, and the back pressure valve group is connected with the rodless cavities of the roll bending cylinders. The servo valve group is used for independently controlling the corresponding roller bending cylinders, the back pressure valve group is connected with rod cavities of the multiple roller bending cylinders, and the back pressure valve group is used for rapidly resetting the roller bending cylinders. The device can adjust the roll bending amount on line, is suitable for straightening various plate type defects, effectively reduces the blind area of the roll bending effect, and effectively ensures the safety of equipment and a control system at the same time.

Description

Technical Field

[0001] The invention belongs to the technical field of straightening machines, and in particular relates to a multi-point bending roller hydraulic control system and a control method for a plate straightening machine. Background Art

[0002] Competition in the medium and thick plate market is becoming increasingly fierce, and the focus of medium and thick plate development has shifted from pursuing output to pursuing quality. Plate straightening machines are an important part of plate quality assurance. In pursuit of higher quality, straightening machines with bending roller capabilities have become a must in medium and thick plate production lines. This type of straightening machine can produce straightening working rolls with a certain amount of curvature, which can eliminate the bounce of the frame. At the same time, due to the existence of the bending roller, the transverse plate shape of the plate can be effectively improved, and the flatness accuracy of the plate can be improved.

[0003] The main roll bending form in the prior art is single-cylinder roll bending, which consists of a movable beam consisting of two split beams on the left and right, with a hinge point in the middle. The roll bending cylinder can bend the upper roll system through the eccentric shaft and the hinge point. The single-cylinder roll bending control system is as follows: Figure 1 As shown, when using positive bending, it can only work on the middle position of the steel plate during the straightening process, and when using negative bending, it can only work on the positions on both sides of the steel plate, resulting in a large blind spot in the position where the bending roller acts, and the safety of the equipment cannot be guaranteed when overload occurs. Summary of the invention

[0004] In order to at least partially solve the technical problems existing in the above-mentioned prior art, the present invention provides a multi-point bending roller hydraulic control system and control method for a plate straightening machine.

[0005] The multi-point bending roll hydraulic control system of the plate straightening machine of the present invention comprises a plurality of servo valve groups, a plurality of bending roll cylinders and a back pressure valve group, wherein: the plurality of servo valve groups respectively correspond to the plurality of bending roll cylinders, the servo valve groups are connected to the rodless cavities of the bending roll cylinders, the servo valve groups are used to independently control the corresponding bending roll cylinders, the back pressure valve groups are respectively connected to the rod cavities of the plurality of bending roll cylinders, and the back pressure valve groups are used to quickly reset the bending roll cylinders.

[0006] Furthermore, in the above-mentioned multi-point bending roll hydraulic control system of the plate straightening machine, the servo valve group includes a servo valve, an electromagnetic ball valve, a first overflow valve and a pressure sensor, the servo valve is used to dynamically adjust and control the stroke position of the corresponding bending roll cylinder, the electromagnetic ball valve is arranged between the servo valve and the bending roll cylinder, the electromagnetic ball valve is used to control the hydraulic oil circuit to supply oil to the rodless chamber of the bending roll cylinder, the first overflow valve is arranged on the oil circuit between the electromagnetic ball valve and the bending roll cylinder, the first overflow valve is used to ensure that the electromagnetic ball valve outputs a safe oil pressure, the pressure sensor is arranged in parallel with the bending roll cylinder, and the pressure sensor is used to monitor the oil pressure obtained by the rodless chamber of the bending roll cylinder and control the operation of the electromagnetic ball valve.

[0007] Furthermore, in the above-mentioned multi-point bending roll hydraulic control system of the plate straightening machine, the back pressure valve group includes a hydraulic one-way valve, an electromagnetic reversing valve, a pressure reducing valve, a second overflow valve and a pressure relay. The electromagnetic reversing valve is arranged on the hydraulic one-way valve control oil circuit to control the hydraulic oil circuit to supply oil to the rod chamber of the bending roll cylinder. The pressure reducing valve is arranged at the hydraulic oil output end of the hydraulic one-way valve to control the hydraulic oil output pressure of the hydraulic one-way valve. The second overflow valve is arranged between the pressure reducing valve and the bending roll cylinder. The second overflow valve is used to ensure that the pressure reducing valve outputs a safe oil pressure. The pressure relay is arranged in parallel with the bending roll cylinder. The pressure relay is used to monitor the oil pressure obtained by the rod chamber of the bending roll cylinder.

[0008] Further, in the above-mentioned plate straightening machine multi-point bending roller hydraulic control system, the servo valve is a three-position four-way servo valve, the P port of the servo valve is connected to the system pressure oil, the T port is connected to the system return oil, the A port is connected to the electromagnetic ball valve, and the B port is blocked;

[0009] The P port of the electromagnetic ball valve is connected to the A port of the servo valve, the T port is connected to the system oil return, and the A port is connected to the rodless chamber of the bending roller cylinder.

[0010] Furthermore, in the above-mentioned plate straightening machine multi-point bending roller hydraulic control system, the P port of the electromagnetic reversing valve is connected to the system pressure oil, the T port is connected to the system return oil, the A port is connected to the control end of the hydraulic one-way valve, and the B port is blocked.

[0011] Furthermore, in the above-mentioned multi-point bending roller hydraulic control system of the plate straightening machine, a displacement sensor is arranged at the bottom of the bending roller cylinder.

[0012] On the other hand, the control method implemented by the multi-point bending roller hydraulic control system of the plate straightening machine is used for plate straightening. Two groups of bending roller cylinders are set at the inlet and outlet sides of the straightening machine. According to different plate width specifications, each group can be set with 4 or 6 bending roller cylinders. The method includes:

[0013] Each corresponding bending roller cylinder is individually controlled by an independent servo valve group. When in use, different bending pressures are set for each bending roller cylinder by adjusting the servo valves on each servo valve group according to the defects of the steel plate. At the same time, the bending roller amount is monitored in real time through the displacement sensor, and a closed-loop control is formed with the servo valve to dynamically compensate for the elastic deformation of the upper roller system of the straightening machine and adjust the curvature of the upper roller system, so as to achieve a constant roller gap during the straightening process and ensure the overall straightness of the steel plate;

[0014] When the pressure sensor detects that the working pressure of the roll bending cylinder exceeds the safety pressure set by the first relief valve, the pressure sensor controls the electromagnetic ball valve to close and unload. At the same time, the electromagnetic reversing valve opens to control the hydraulic control check valve to open. The hydraulic oil quickly enters the rod cavity of the roll bending cylinder after the oil pressure is controlled by the pressure reducing valve and the second relief valve, so that the rodless cavity of the roll bending cylinder is quickly unloaded. The back pressure valve group pushes the roll bending cylinder plunger back, and the balance cylinder quickly lifts the roll system to prevent damage to the equipment caused by steel jamming.

[0015] The plate straightening machine multi-point bending roller hydraulic control system and control method of the present invention have the following advantages and beneficial effects:

[0016] In the control system of the present invention, each bending roller cylinder is independently controlled by an independent servo valve group, which can realize online adjustment and respond quickly when the system is overloaded, effectively avoiding equipment damage. The control method implemented by the system effectively reduces the blind area of ​​the bending roller action, is suitable for straightening of various plate defects, dynamically compensates for the elastic deformation of the upper roller device of the straightening machine and adjusts the curvature of the upper roller device, effectively improving the straightening quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings in the following descriptions are only used to further understand the embodiments of the present invention and constitute a part of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0018] Figure 1 It is a structural schematic diagram of a bending roll hydraulic control system in the prior art;

[0019] Figure 2 It is a structural schematic diagram of a multi-point bending roller hydraulic control system of a plate straightening machine of the present invention;

[0020] Figure 3 It is a schematic diagram of the structure of the servo valve group of the multi-point bending roller hydraulic control system of the plate straightening machine of the present invention;

[0021] Figure 4 It is a schematic diagram of the structure of the back pressure valve group of the multi-point bending roller hydraulic control system of the plate straightening machine of the present invention;

[0022] Figure 5 This is a schematic diagram of the installation structure of the multi-point bending roller hydraulic control system of the plate straightening machine of the present invention when it is in use.

[0023] Description of reference numerals:

[0024] 1: servo valve group, 11: servo valve, 12: electromagnetic ball valve, 13: first overflow valve, 14: pressure sensor;

[0025] 2: Bending roller cylinder;

[0026] 3: back pressure valve group, 31: hydraulic check valve, 32: solenoid reversing valve, 33: pressure reducing valve, 34: second relief valve, 35: pressure relay;

[0027] 4: Displacement sensor. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0029] like Figures 2 to 4 As shown, the multi-point bending roller hydraulic control system of the plate straightening machine of the present invention includes multiple servo valve groups 1, multiple bending roller cylinders 2 and a back pressure valve group 3, wherein: the multiple servo valve groups 1 correspond to the multiple bending roller cylinders 2 respectively, the servo valve group 1 is connected to the rodless cavity of the bending roller cylinder 2, the servo valve group 1 is used to independently control the corresponding bending roller cylinder 2, the back pressure valve group 3 is connected to the rod cavity of the multiple bending roller cylinders 2 respectively, and the back pressure valve group 3 is used to quickly reset the bending roller cylinder 2.

[0030] Furthermore, in the above-mentioned plate straightening machine multi-point bending roller hydraulic control system, the servo valve group 1 includes a servo valve 11, an electromagnetic ball valve 12, a first overflow valve 13 and a pressure sensor 14. The servo valve 11 is used to dynamically adjust and control the stroke position of the corresponding bending roller cylinder 2. The electromagnetic ball valve 12 is arranged between the servo valve 11 and the bending roller cylinder 2. The electromagnetic ball valve 12 is used to control the hydraulic oil circuit to supply oil to the rodless chamber of the bending roller cylinder 2. The first overflow valve 13 is arranged on the oil circuit between the electromagnetic ball valve 12 and the bending roller cylinder 2. The first overflow valve 13 is used to ensure that the electromagnetic ball valve 12 outputs a safe oil pressure. The pressure sensor 14 is arranged in parallel with the bending roller cylinder 2. The pressure sensor 14 is used to monitor the oil pressure obtained by the rodless chamber of the bending roller cylinder and control the operation of the electromagnetic ball valve 12.

[0031] Specifically, after the system hydraulic oil enters the servo valve 11, the hydraulic oil after the pressure is adjusted by the servo valve 11 enters the electromagnetic ball valve 12, and the hydraulic oil is controlled by the electromagnetic ball valve 12 to start the bending roll cylinder 2, thereby effectively preventing misoperation and playing a safety protection role for the bending roll cylinder 2. When the hydraulic oil enters the rodless chamber of the bending roll cylinder 2, the first relief valve 13 is used to ensure that the hydraulic oil pressure is within the safety pressure range, and the pressure sensor 14 is used for real-time monitoring. When the hydraulic oil pressure exceeds the safety pressure, the first relief valve 13 is unloaded, and the pressure sensor 14 controls the electromagnetic ball valve 12 to close.

[0032] Furthermore, in the above-mentioned plate straightening machine multi-point bending roller hydraulic control system, the back pressure valve group 3 includes a hydraulic one-way valve 31, an electromagnetic reversing valve 32, a pressure reducing valve 33, a second overflow valve 34 and a pressure relay 35. The electromagnetic reversing valve 32 is arranged on the hydraulic one-way valve 31 control oil circuit to control the hydraulic oil circuit to supply oil to the rod chamber of the bending roller cylinder 2. The pressure reducing valve 33 is arranged at the hydraulic oil output end of the hydraulic one-way valve 31 to control the hydraulic oil output pressure of the hydraulic one-way valve 31. The second overflow valve 34 is arranged between the pressure reducing valve 33 and the bending roller 2 cylinder. The second overflow valve 34 is used to ensure that the pressure reducing valve 33 outputs a safe oil pressure. The pressure relay 35 is arranged in parallel with the bending roller cylinder 2. The pressure relay 35 is used to monitor the oil pressure obtained in the rod chamber of the bending roller cylinder 2.

[0033] Specifically, when the electromagnetic ball valve 12 loses power, the electromagnetic reversing valve 32 opens, controlling the hydraulic one-way valve 31 to open, and the hydraulic oil enters the second overflow valve 34 after the hydraulic oil pressure is controlled by the pressure reducing valve 33. The second overflow valve 34 ensures that the pressure of the hydraulic oil entering the rod chamber of the bending roller cylinder 2 is within a safe range, and real-time monitoring is performed through the pressure relay 35.

[0034] Further, in the above-mentioned plate straightening machine multi-point bending roller hydraulic control system, the servo valve 11 is a three-position four-way servo valve, the P port of the servo valve 11 is connected to the system pressure oil, the T port is connected to the system return oil, the A port is connected to the electromagnetic ball valve 12, and the B port is blocked;

[0035] The P port of the electromagnetic ball valve 12 is connected to the A port of the servo valve 11 , the T port is connected to the system oil return, and the A port is connected to the rodless chamber of the bending roller cylinder 2 .

[0036] Furthermore, in the above-mentioned plate straightening machine multi-point bending roller hydraulic control system, the P port of the electromagnetic reversing valve 32 is connected to the system pressure oil, the T port is connected to the system return oil, the A port is connected to the control end of the hydraulic one-way valve 31, and the B port is blocked.

[0037] Furthermore, in the above-mentioned multi-point bending roller hydraulic control system of the plate straightening machine, a displacement sensor 4 is arranged at the bottom of the bending roller cylinder 2.

[0038] On the other hand, the control method implemented by the multi-point bending roller hydraulic control system of the plate straightening machine is used for plate straightening. Two groups of bending roller cylinders 2 are set at the inlet and outlet sides of the straightening machine. According to different plate width specifications, each group can be provided with 4 or 6 bending roller cylinders 2. The method includes:

[0039] Each corresponding bending roller cylinder 2 is individually controlled by an independent servo valve group 1. When in use, different bending pressures are set for each bending roller cylinder 2 by adjusting the servo valves 11 on each servo valve group 1 according to the defects of the steel plate. At the same time, the bending roller amount is monitored in real time by the displacement sensor 4, and a closed-loop control is formed with the servo valve 11 to dynamically compensate for the elastic deformation of the upper roller system device of the straightening machine and adjust the curvature of the upper roller system device, so as to achieve a constant roller gap during the straightening process and ensure the overall straightness of the steel plate;

[0040] Specifically, the steel plate has defects such as middle wave, side wave, 3 / 4 wave and compound wave. Each bending roller mode corresponds to the expansion and contraction amount of each bending roller cylinder 2, such as Figure 5 As shown, when a middle wave appears on the steel plate, the third and fourth bending roller cylinders on the inlet and outlet sides can be started; when a side wave appears, the first and sixth bending roller cylinders on the inlet and outlet sides can be started; when a 3 / 4 wave appears on the steel plate, the second or fifth bending roller cylinder on the inlet and outlet sides can be started, or the second and fifth bending roller cylinders can be started at the same time; when a compound wave appears on the steel plate, the bending roller cylinders at the corresponding positions can be started for bending operations according to the specific positions of each defect; different combinations of bending roller modes can be adjusted at any time to cope with different defects of the steel plate.

[0041] When the pressure sensor 14 detects that the working pressure of the bending roll cylinder 2 exceeds the safety pressure set by the first relief valve 13, the pressure sensor 14 controls the electromagnetic ball valve 12 to close and unload. At the same time, the electromagnetic reversing valve 32 opens to control the hydraulic control one-way valve to open. The hydraulic oil quickly enters the rod cavity of the bending roll cylinder 2 after the oil pressure is controlled by the pressure reducing valve 33 and the second relief valve 34, so that the rodless cavity of the bending roll cylinder 2 is quickly unloaded, the back pressure valve group 3 pushes back the plunger of the bending roll cylinder 2, and the balancing cylinder quickly lifts the roll system to prevent damage to the equipment caused by steel jamming.

[0042] In summary, compared with the prior art, the plate straightening machine multi-point bending roller hydraulic control system and control method of the present invention have the following advantages and beneficial effects:

[0043] In the control system of the present invention, each bending roller cylinder is independently controlled by an independent servo valve group, which can realize online adjustment and respond quickly when the system is overloaded, effectively avoiding equipment damage. The control method implemented by the system effectively reduces the blind area of ​​the bending roller action, is suitable for straightening of various plate defects, dynamically compensates for the elastic deformation of the upper roller device of the straightening machine and adjusts the curvature of the upper roller device, effectively improving the straightening quality.

[0044] It should be noted that, in this article, unless otherwise clearly specified and limited, the term "connection" or its synonyms should be understood in a broad sense. For example, "connection" can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. Moreover, expressions such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. At the same time, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such a process, method, article or device. In addition, "front", "back", "left", "right", "upper" and "lower" in this article are all referenced to the placement state shown in the accompanying drawings.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-point bending roller hydraulic control system for a plate straightening machine. It is characterized in that The multi-point bending roller hydraulic control system of the plate straightening machine includes multiple servo valve groups, multiple bending roller cylinders and a back pressure valve group, wherein: the multiple servo valve groups correspond to the multiple bending roller cylinders respectively, the servo valve groups are connected to the rodless cavity of the bending roller cylinder, the servo valve groups are used to independently control the corresponding bending roller cylinders, the back pressure valve groups are respectively connected to the rod cavity of the multiple bending roller cylinders, and the back pressure valve groups are used to quickly reset the bending roller cylinders.

2. The multi-point bending roller hydraulic control system for a plate straightening machine according to claim 1, It is characterized in that The servo valve group includes a servo valve, an electromagnetic ball valve, a first overflow valve and a pressure sensor. The servo valve is used to dynamically adjust and control the stroke position of the corresponding roll bending cylinder. The electromagnetic ball valve is arranged between the servo valve and the roll bending cylinder. The electromagnetic ball valve is used to control the hydraulic oil circuit to supply oil to the rodless chamber of the roll bending cylinder. The first overflow valve is arranged on the oil circuit between the electromagnetic ball valve and the roll bending cylinder. The first overflow valve is used to ensure that the electromagnetic ball valve outputs a safe oil pressure. The pressure sensor is arranged in parallel with the roll bending cylinder. The pressure sensor is used to monitor the oil pressure obtained by the rodless chamber of the roll bending cylinder and control the operation of the electromagnetic ball valve.

3. The multi-point bending roller hydraulic control system of the plate straightening machine according to claim 1, It is characterized in that The back-pressure valve group includes a hydraulic one-way valve, an electromagnetic reversing valve, a pressure reducing valve, a second overflow valve and a pressure relay. The electromagnetic reversing valve is arranged on the hydraulic one-way valve control oil circuit to control the hydraulic oil circuit to supply oil to the rod chamber of the bending roll cylinder. The pressure reducing valve is arranged on the hydraulic oil output end of the hydraulic one-way valve to control the hydraulic oil output pressure of the hydraulic one-way valve. The second overflow valve is arranged between the pressure reducing valve and the bending roll cylinder. The second overflow valve is used to ensure that the pressure reducing valve outputs a safe oil pressure. The pressure relay is arranged in parallel with the bending roll cylinder. The pressure relay is used to monitor the oil pressure obtained by the rod chamber of the bending roll cylinder.

4. The multi-point bending roller hydraulic control system for a plate straightening machine according to claim 2, It is characterized in that The servo valve is a three-position four-way servo valve, the P port of the servo valve is connected to the system pressure oil, the T port is connected to the system return oil, the A port is connected to the electromagnetic ball valve, and the B port is blocked; The P port of the electromagnetic ball valve is connected to the A port of the servo valve, the T port is connected to the system oil return, and the A port is connected to the rodless chamber of the bending roller cylinder.

5. The multi-point bending roller hydraulic control system for a plate straightening machine according to claim 3, It is characterized in that The P port of the electromagnetic reversing valve is connected to the system pressure oil, the T port is connected to the system return oil, the A port is connected to the control end of the hydraulic one-way valve, and the B port is blocked.

6. The multi-point bending roller hydraulic control system for a plate straightening machine according to claim 1, It is characterized in that A displacement sensor is arranged at the bottom of the roller bending cylinder.

7. A control method implemented by using a multi-point bending roller hydraulic control system for a plate straightening machine according to any one of claims 1 to 6, for plate straightening, It is characterized in that Two groups of bending roll cylinders are set at the inlet and outlet sides of the straightening machine. According to the different plate width specifications, each group can be set with 4 or 6 bending roll cylinders. The method includes: Each corresponding bending roller cylinder is individually controlled by an independent servo valve group. When in use, different bending pressures are set for each bending roller cylinder by adjusting the servo valves on each servo valve group according to the defects of the steel plate. At the same time, the bending roller amount is monitored in real time through the displacement sensor, and a closed-loop control is formed with the servo valve to dynamically compensate for the elastic deformation of the upper roller system of the straightening machine and adjust the curvature of the upper roller system, so as to achieve a constant roller gap during the straightening process and ensure the overall straightness of the steel plate; When the pressure sensor detects that the working pressure of the roll bending cylinder exceeds the safety pressure set by the first relief valve, the pressure sensor controls the electromagnetic ball valve to close and unload. At the same time, the electromagnetic reversing valve opens to control the hydraulic control check valve to open. The hydraulic oil quickly enters the rod cavity of the roll bending cylinder after the oil pressure is controlled by the pressure reducing valve and the second relief valve, so that the rodless cavity of the roll bending cylinder is quickly unloaded. The back pressure valve group pushes the roll bending cylinder plunger back, and the balance cylinder quickly lifts the roll system to prevent damage to the equipment caused by steel jamming.

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