A heavy pressure straightening machine for a billet continuous casting machine, a hydraulic control system for the straightening machine and a control method thereof

Abstract

The present invention relates to the field of metallurgical equipment, and in particular to a heavy-pressure straightening machine for a square billet continuous casting machine, a straightening machine hydraulic control system and a control method. A displacement sensor is arranged in each straightening machine servo hydraulic cylinder, and the hydraulic circuits of the servo hydraulic cylinder plug cavity and the rod cavity are respectively connected with pressure sensors. Two straightening machine servo hydraulic cylinders are used to control the lifting and pressing functions of the upper rollers of the heavy-pressure straightening machines. One heavy-pressure balancing cylinder is used to lift the upper rollers of the straightening machines. The heavy-pressure balancing cylinder adopts a rod cavity to connect the pressure after the pressure is reduced by a three-way pressure reducing valve. By setting the pressure of the three-way pressure reducing valve, it is ensured that the upper rollers of the heavy-pressure straightening machine are always in close contact with the piston rod ends of the two straightening machine servo hydraulic cylinders. The pressure sensor is used to compensate for the equipment gap and equipment deformation during the working process of the heavy-pressure straightening machine, so as to achieve the required equipment control accuracy.

Description

Technical Field

[0001] The invention relates to the field of metallurgical equipment, and in particular to a heavy-pressure straightening machine for a square billet continuous casting machine, a hydraulic control system for the straightening machine and a control method. Background Art

[0002] Square billet continuous casting machines generally have internal quality problems such as internal center segregation, center porosity and shrinkage, which cause certain quality defects of continuous casting billets. The light pressure reduction technology of continuous casting machines can effectively solve the problem of internal center segregation of continuous casting billets, but it has little effect on the problems of internal porosity and shrinkage of continuous casting billets. In order to solve the problems of internal porosity and shrinkage of continuous casting billets, a heavy pressure continuous casting production process with high continuous casting quality and high production efficiency is provided.

[0003] The straightening machine of the billet continuous casting machine usually uses one straightening machine hydraulic cylinder to control the heavy pressure down function. Since the heavy pressure down process requires the maximum pressing amount of a single roller to be about 20 mm, and the billet has been solidified at the heavy pressure down position, the straightening machine pressing force is very large, so the straightening machine hydraulic cylinder required by the equipment is also large, thereby increasing the size of the straightening machine equipment itself. At the same time, one straightening machine hydraulic cylinder is prone to cause the billet to deviate during the heavy pressure down process. The present invention provides a hydraulic control system comprising one balancing cylinder and two straightening machine servo hydraulic cylinders. Summary of the invention

[0004] The present invention overcomes the shortcomings of the prior art and provides a square billet continuous casting machine heavy pressure straightening machine, a straightening machine hydraulic control system and a control method, especially having the characteristics of realizing precise control of the roll gap during the heavy pressure of the straightening machine, preventing the billet from running off track, and preventing the servo hydraulic cylinder of the straightening machine from being subjected to lateral force, thereby ensuring the reliability and long service life of the servo hydraulic cylinder of the straightening machine.

[0005] The technical problem solved by the present invention can be achieved by adopting the following technical solutions:

[0006] A square billet continuous casting machine under heavy pressure straightening machine, at least comprises a straightening machine frame, the top of the inner side of the straightening machine frame is connected to the hydraulic control system of the square billet continuous casting machine under heavy pressure, two straightening machine lower roller bearing seats are connected to the bottom of the inner side of the straightening machine frame, a straightening machine lower roller is connected between the two straightening machine lower roller bearing seats, the top of the straightening machine lower roller is connected to the straightening machine upper roller through the casting, the straightening machine upper roller is connected to the middle position of the inner side of the straightening machine frame through two straightening machine upper roller bearing seats, the straightening machine upper roller is controlled by the hydraulic control system of the square billet continuous casting machine under heavy pressure, the tops of the two straightening machine upper roller bearing seats are also connected by a crossbeam, the two straightening machine upper roller bearing seats are fixed to the straightening machine frame by bolts, and one end of the straightening machine upper roller is also connected to the straightening machine transmission mechanism.

[0007] The hydraulic control system of a heavy-pressure straightening machine of a square billet continuous casting machine comprises a proportional directional valve, a servo hydraulic cylinder of the straightening machine, a three-way pressure reducing valve, a balancing cylinder, a bladder-type accumulator and a PLC control unit. The tail of the servo hydraulic cylinder of the straightening machine is connected to the top of the inner side of the straightening machine frame through a flange. The piston rod end of the servo hydraulic cylinder of the straightening machine is a mushroom head type. The piston rod end of the servo hydraulic cylinder of the straightening machine contacts the top of the upper roller bearing seat of the straightening machine through the mushroom head. One end of the balancing cylinder is hinged to the top of the inner side of the straightening machine frame, and the other end of the balancing cylinder is hinged to the top of the inner side of the straightening machine frame. It is hinged at the middle part of the crossbeam between the tops of the upper roller bearing seats of the two straightening machines. One end of the proportional directional valve and the three-way pressure reducing valve are connected to the hydraulic system pressure oil supply port P and the hydraulic system return oil port T through oil pipelines. The other end of the proportional directional valve is connected to the servo hydraulic cylinder of the straightening machine through the oil pipeline. The other end of the three-way pressure reducing valve is connected to the balance cylinder and the bladder accumulator through the oil pipeline. One end of the three-way pressure reducing valve is also connected to the hydraulic system leakage oil port L through the oil pipeline. The PLC control unit is used to control the servo hydraulic cylinder of the straightening machine.

[0008] The proportional directional valve and the straightening machine servo hydraulic cylinder are both provided with two groups, the proportional directional valve includes a first proportional directional valve and a second proportional directional valve, the straightening machine servo hydraulic cylinder includes a first straightening machine servo hydraulic cylinder and a second straightening machine servo hydraulic cylinder, the tails of the first straightening machine servo hydraulic cylinder and the second straightening machine servo hydraulic cylinder are connected to the top of the inner side of the straightening machine frame through a flange, the piston rod ends of the first straightening machine servo hydraulic cylinder and the second straightening machine servo hydraulic cylinder are mushroom head type, the piston rod ends of the first straightening machine servo hydraulic cylinder and the second straightening machine servo hydraulic cylinder are in contact with the top of the two straightening machine upper roller bearing seats through the mushroom head, one end of the first proportional directional valve and the second proportional directional valve are connected to the hydraulic system pressure oil supply port P and the hydraulic system return oil port T through oil pipelines respectively, the other end of the first proportional directional valve is connected to the first straightening machine servo hydraulic cylinder through an oil pipeline, and the other end of the second proportional directional valve is connected to the second straightening machine servo hydraulic cylinder through an oil pipeline.

[0009] The oil pipeline connecting the first proportional directional valve and the first straightening machine servo hydraulic cylinder and the oil pipeline connecting the second proportional directional valve and the second straightening machine servo hydraulic cylinder are both connected with pressure sensors, and the straightening machine servo hydraulic cylinder and the second straightening machine servo hydraulic cylinder are both provided with displacement sensors.

[0010] The pressure sensor includes a first pressure sensor, a second pressure sensor, a third pressure sensor and a fourth pressure sensor. The first pressure sensor and the second pressure sensor are connected to the oil pipeline connecting the first proportional directional valve and the first straightening machine servo hydraulic cylinder, and the third pressure sensor and the fourth pressure sensor are connected to the oil pipeline connecting the second proportional directional valve and the second straightening machine servo hydraulic cylinder. The displacement sensor includes a first displacement sensor and a second displacement sensor. The first displacement sensor is connected to the first straightening machine servo hydraulic cylinder, and the second displacement sensor is connected to the second straightening machine servo hydraulic cylinder.

[0011] The transmission mechanism of the tension and straightening machine is composed of a motor and a reducer.

[0012] A method for hydraulic control of a heavy pressure pull-down straightening machine of a billet continuous casting machine comprises any one of the above-mentioned hydraulic control systems for a heavy pressure pull-down straightening machine of a billet continuous casting machine, comprising the following steps:

[0013] Step 1: The transmission device of the straightening machine drives the upper roller of the straightening machine to rotate between two upper roller bearing seats of the straightening machine. While the upper roller of the straightening machine rotates, the lower roller of the straightening machine is driven to rotate between two lower roller bearing seats of the straightening machine through the ingot;

[0014] Step 2: The upper roller of the straightening machine controls the first straightening machine servo hydraulic cylinder, the second straightening machine servo hydraulic cylinder and the balance cylinder through the heavy pressure of the billet continuous casting machine, and then controls the roller gap position composed of the upper roller of the straightening machine and the lower roller of the straightening machine;

[0015] Step 3: The pressure oil P1 reduced by the three-way pressure reducing valve is connected to the balancing cylinder rod chamber, and a bladder accumulator is arranged behind the three-way pressure reducing valve to stabilize the pressure reduction. By adjusting the P1 pressure, the upper roller bearing seat of the upper roller of the straightening machine is always in close contact with the piston rod mushroom head of the first straightening machine servo hydraulic cylinder and the second straightening machine servo hydraulic cylinder, so as to prevent the deflection of the upper roller of the straightening machine caused by the transmission mechanism of the straightening machine, and prevent the first straightening machine servo hydraulic cylinder and the second straightening machine servo hydraulic cylinder from bearing lateral force;

[0016] Step 4: Control the pressure through the first pressure sensor, the second pressure sensor, the third pressure sensor and the fourth pressure sensor respectively connected to the plug cavity and the rod cavity of the first straightening machine servo hydraulic cylinder and the second straightening machine servo hydraulic cylinder, and the first displacement sensor and the second displacement sensor in the first straightening machine servo hydraulic cylinder and the second straightening machine servo hydraulic cylinder are used to monitor the positions of the telescopic rods in the first straightening machine servo hydraulic cylinder and the second straightening machine servo hydraulic cylinder.

[0017] The beneficial effects of the present invention are:

[0018] Compared with the prior art, the present invention adopts two proportional directional valves to control two servo hydraulic cylinders of the straightening machine under heavy pressure and forms a position closed loop through displacement sensors, realizes displacement compensation of equipment gap and elastic deformation of equipment through pressure sensors, and finally realizes precise control of the roll gap position composed of the upper roller and the lower roller of the straightening machine, the balance cylinder rod chamber is connected to the pressure oil P1 reduced by the three-way pressure reducing valve, and a bladder accumulator is provided to stabilize the reduced pressure pressure, and by adjusting the appropriate P1 pressure, the bearing seat of the upper roller of the straightening machine is always in close contact with the mushroom head of the piston rod of the servo hydraulic cylinder of the straightening machine, which can prevent the deflection of the upper roller of the straightening machine caused by the deadweight of the transmission mechanism of the straightening machine, and can prevent the servo hydraulic cylinder of the straightening machine from being subjected to lateral force, thereby improving the reliability and service life of the hydraulic cylinder of the straightening machine, realizing displacement compensation of equipment gap and elastic deformation of equipment through pressure sensors, and finally realizing precise control of the roll gap position composed of the upper roller and the lower roller of the straightening machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0020] Figure 1 It is a structural schematic diagram of the tension and straightening machine of the present invention.

[0021] Figure 2 The present invention is a schematic diagram of the hydraulic principle structure of the hydraulic control system of the heavy pressure down-drawing straightener of the square billet continuous casting machine.

[0022] In the figure: 1.1-first proportional directional valve; 1.2-second proportional directional valve; 2.1-first straightening machine servo hydraulic cylinder; 2.2-second straightening machine servo hydraulic cylinder; 3.1-first displacement sensor; 3.2-second displacement sensor; 4.1-first pressure sensor; 4.2-second pressure sensor; 4.3-third pressure sensor; 4.4-fourth pressure sensor; 5.1-three-way pressure reducing valve; 6.1-balance cylinder; 7.1-bladder accumulator; 8.1-upper roller of straightening machine; 9.1-bearing seat of upper roller of straightening machine; 10.1-transmission equipment of straightening machine; 11.1-casting billet; 12.1-lower roller of straightening machine; 13.1-bearing seat of lower roller of straightening machine; P hydraulic system pressure oil supply port; T hydraulic system oil return port; L hydraulic system leakage port; P1 pressure after pressure reduction by three-way pressure reducing valve. DETAILED DESCRIPTION

[0023] Embodiment 1:

[0024] Reference Figure 1, is a structural schematic diagram of Example 1 of the present invention, a square billet continuous casting machine weight pressure drawing and straightening machine, at least comprising a drawing and straightening machine frame, the top of the inner side of the drawing and straightening machine frame is connected to the hydraulic control system of the square billet continuous casting machine weight pressure drawing and straightening machine, the bottom of the inner side of the drawing and straightening machine frame is connected to two drawing and straightening machine lower roller bearing seats 13.1, a drawing and straightening machine lower roller 12.1 is connected between the two drawing and straightening machine lower roller bearing seats 13.1, and the top of the drawing and straightening machine lower roller 12.1 is connected to the drawing and straightening machine through the billet 11.1. The upper roller 8.1 of the straightening machine is connected to the middle position of the inner side of the straightening machine frame through two upper roller bearing seats 9.1 of the straightening machine. The upper roller 8.1 of the straightening machine is controlled by the hydraulic control system of the straightening machine under the heavy pressure of the billet continuous casting machine. The tops of the two upper roller bearing seats 9.1 of the straightening machine are also connected by a crossbeam. The two upper roller bearing seats 9.1 of the straightening machine are fixed to the straightening machine frame by bolts. One end of the upper roller 8.1 of the straightening machine is also connected to the straightening machine transmission mechanism 10.1.

[0025] Furthermore, the transmission mechanism 10.1 of the tension and straightening machine is composed of a motor and a reducer.

[0026] In actual use: the lifting and pressing functions of the upper roller 8.1 of the heavy pressure straightening machine are controlled by the hydraulic control system of the heavy pressure straightening machine of the billet continuous casting machine. The motor and the reducer in the transmission mechanism 10.1 of the straightening machine are used to drive the upper roller 8.1 of the straightening machine to rotate between the two upper roller bearing seats 9.1 of the straightening machine. When the upper roller 8.1 of the straightening machine rotates, the lower roller 12.1 of the straightening machine is driven to rotate between the two lower roller bearing seats 13.1 of the straightening machine. During the working process of the heavy pressure straightening machine, the roll gap value is remotely given by the PLC control unit, and the precise roll gap control requirements are achieved through the control of the hydraulic control system of the heavy pressure straightening machine of the billet continuous casting machine.

[0027] Embodiment 2:

[0028] Reference Figure 2Compared with Example 1, the difference of this embodiment is that: a hydraulic control system of a heavy-pressure straightening machine of a square billet continuous casting machine comprises a proportional directional valve, a servo hydraulic cylinder of the straightening machine, a three-way pressure reducing valve 5.1, a balancing cylinder 6.1, a bladder accumulator 7.1 and a PLC control unit. The tail of the servo hydraulic cylinder of the straightening machine is connected to the top of the inner side of the straightening machine frame through a flange. The piston rod end of the servo hydraulic cylinder of the straightening machine is a mushroom head type. The piston rod end of the servo hydraulic cylinder of the straightening machine is in contact with the top of the upper roller bearing seat 9.1 of the straightening machine through the mushroom head. One end of the balancing cylinder 6.1 is hinged to the top of the inner side of the straightening machine frame. The other end of the balance cylinder 6.1 is hinged to the middle of the crossbeam between the tops of the two upper roller bearing seats 9.1 of the straightening machine. One end of the proportional directional valve and the three-way pressure reducing valve 5.1 are both connected to the hydraulic system pressure oil supply port P and the hydraulic system return oil port T of the hydraulic system through oil pipelines. The other end of the proportional directional valve is connected to the servo hydraulic cylinder of the straightening machine through the oil pipeline. The other end of the three-way pressure reducing valve 5.1 is connected to the balance cylinder 6.1 and the bladder accumulator 7.1 through the oil pipeline. One end of the three-way pressure reducing valve 5.1 is also connected to the hydraulic system leakage oil port L through the oil pipeline. The PLC control unit is used to control the servo hydraulic cylinder of the straightening machine.

[0029] Further, the proportional directional valve and the straightening machine servo hydraulic cylinder are both provided with two groups, the proportional directional valve includes a first proportional directional valve 1.1 and a second proportional directional valve 1.2, the straightening machine servo hydraulic cylinder includes a first straightening machine servo hydraulic cylinder 2.1 and a second straightening machine servo hydraulic cylinder 2.2, the tails of the first straightening machine servo hydraulic cylinder 2.1 and the second straightening machine servo hydraulic cylinder 2.2 are connected to the top of the inner side of the straightening machine frame through a flange, the piston rod ends of the first straightening machine servo hydraulic cylinder 2.1 and the second straightening machine servo hydraulic cylinder 2.2 are mushroom head type, and the first straightening machine servo hydraulic cylinder 2.1 and the second straightening machine servo hydraulic cylinder 2.2 are provided with a mushroom head type piston rod end ... The piston rod ends of the servo hydraulic cylinder 2.1 of the straightening machine and the servo hydraulic cylinder 2.2 of the second straightening machine are in contact with the top of the upper roller bearing seats 9.1 of the two straightening machines through mushroom heads, one end of the first proportional directional valve 1.1 and the second proportional directional valve 1.2 are connected to the hydraulic system pressure oil supply port P and the hydraulic system return oil port T of the hydraulic system through oil pipelines respectively, the other end of the first proportional directional valve 1.1 is connected to the first straightening machine servo hydraulic cylinder 2.1 through the oil pipeline, and the other end of the second proportional directional valve 1.2 is connected to the second straightening machine servo hydraulic cylinder 2.2 through the oil pipeline.

[0030] Furthermore, the oil pipeline connecting the first proportional directional valve 1.1 and the first straightening machine servo hydraulic cylinder 2.1 and the oil pipeline connecting the second proportional directional valve 1.2 and the second straightening machine servo hydraulic cylinder 2.2 are both connected with pressure sensors, and the straightening machine servo hydraulic cylinder 2.1 and the second straightening machine servo hydraulic cylinder 2.2 are both provided with displacement sensors.

[0031] The pressure sensor further comprises a first pressure sensor 4.1, a second pressure sensor 4.2, a third pressure sensor 4.3 and a fourth pressure sensor 4.4. The first pressure sensor 4.1 and the second pressure sensor 4.2 are connected to the oil pipeline connecting the first proportional directional valve 1.1 and the first straightening machine servo hydraulic cylinder 2.1, the third pressure sensor 4.3 and the fourth pressure sensor 4.4 are connected to the oil pipeline connecting the second proportional directional valve 1.2 and the second straightening machine servo hydraulic cylinder 2.2. The displacement sensor comprises a first displacement sensor 3.1 and a second displacement sensor 3.2. The first displacement sensor 3.1 is connected to the first straightening machine servo hydraulic cylinder 2.1, and the second displacement sensor 3.2 is connected to the second straightening machine servo hydraulic cylinder 2.2.

[0032] Further, the first proportional directional valve 1.1 and the second proportional directional valve 1.2 both include an oil port P, an oil port T, an oil port A and an oil port B. The oil ports P of the first proportional directional valve 1.1 and the second proportional directional valve 1.2 are respectively connected to the hydraulic system pressure oil port P of the hydraulic system through an oil pipeline, and the oil ports T of the first proportional directional valve 1.1 and the second proportional directional valve 1.2 are respectively connected to the hydraulic system return oil port T of the hydraulic system through an oil pipeline. The oil port A of the first proportional directional valve 1.1 is connected to the first straightening machine through an oil pipeline. The oil inlet of the servo hydraulic cylinder 2.1 is connected, the oil port B of the first proportional directional valve 1.1 is connected to the oil outlet of the first straightening machine servo hydraulic cylinder 2.1, the oil port A of the second proportional directional valve 1.2 is connected to the oil inlet of the second straightening machine servo hydraulic cylinder 2.2 through an oil pipeline, the oil port B of the second proportional directional valve 1.2 is connected to the oil outlet of the second straightening machine servo hydraulic cylinder 2.2, the first pressure sensor 4.1 is connected between the oil port A of the first proportional directional valve 1.1 and the oil inlet of the first straightening machine servo hydraulic cylinder 2.1 The second pressure sensor 4.2 is connected to the oil pipeline connecting the oil port B of the first proportional directional valve 1.1 and the oil outlet of the first straightening machine servo hydraulic cylinder 2.1, the third pressure sensor 4.3 is connected to the oil pipeline connecting the oil port A of the second proportional directional valve 1.2 and the oil inlet of the second straightening machine servo hydraulic cylinder 2.2, the fourth pressure sensor 4.4 is connected to the oil pipeline connecting the oil port B of the second proportional directional valve 1.2 and the oil outlet of the second straightening machine servo hydraulic cylinder 2.2, the three-way pressure reducing The valve 5.1 includes an oil inlet P, an oil outlet, an oil return port T and a leakage oil port L. The oil inlet P of the three-way pressure reducing valve 5.1 is connected to the hydraulic system pressure oil supply port P of the hydraulic system through an oil pipeline, the oil return port T of the three-way pressure reducing valve 5.1 is connected to the hydraulic system oil return port T of the hydraulic system through an oil pipeline, the leakage oil port L of the three-way pressure reducing valve 5.1 is connected to the hydraulic system leakage oil port L of the hydraulic system through an oil pipeline, and the oil outlet of the three-way pressure reducing valve 5.1 is connected to the balance cylinder 6.1 and the bladder accumulator 7.1 through the oil pipeline.

[0033] The heavy pressure straightening machine adopts two proportional directional valves, namely the first proportional directional valve 1.1 and the second proportional directional valve 1.2, to control two straightening machine servo hydraulic cylinders, namely the first straightening machine servo hydraulic cylinder 2.1 and the second straightening machine servo hydraulic cylinder 2.2, and forms a position closed loop through the first displacement sensor 3.1 and the second displacement sensor 3.2 in the first straightening machine servo hydraulic cylinder 2.1 and the second straightening machine servo hydraulic cylinder 2.2. The output force of the hydraulic cylinder is calculated through the first pressure sensor 4.1, the second pressure sensor 4.2, the third pressure sensor 4.3 and the fourth pressure sensor 4.4 and the specifications of the first straightening machine servo hydraulic cylinder 2.1 and the second straightening machine servo hydraulic cylinder 2.2, and the computer compensates for the equipment rigid deformation caused by the different output forces and eliminates the internal gap of the equipment. The gap is finally achieved by accurately controlling the position of the roll gap formed by the upper roller 8.1 and the lower roller 12.1 of the straightening machine, that is, the balance cylinder 6.1 under heavy pressure adopts a rod cavity to connect the pressure after the pressure is reduced by the three-way pressure reducing valve 5.1. By setting the pressure of the three-way pressure reducing valve 5.1, it is ensured that the upper roller 8.1 of the straightening machine under heavy pressure is always in close contact with the piston rod ends of the servo hydraulic cylinders of the two straightening machines. During the operation of the straightening machine under heavy pressure, the servo hydraulic cylinders of the two straightening machines remotely give the roll gap value through the PLC control unit. Two proportional directional valves and two displacement sensors form a position closed-loop control to lift and press the servo hydraulic cylinders of the straightening machine to achieve the precise roll gap control requirements. Four pressure sensors are used to compensate for the equipment gap and equipment deformation during the operation of the straightening machine under heavy pressure to achieve the required equipment control accuracy.

[0034] Embodiment 3:

[0035] A method for hydraulic control of a heavy pressure pull-down straightening machine of a billet continuous casting machine includes a hydraulic control system of a heavy pressure pull-down straightening machine of a billet continuous casting machine described in Example 2, comprising the following steps:

[0036] Step 1: The straightening machine transmission device 10.1 drives the straightening machine upper roller 8.1 to rotate between two straightening machine upper roller bearing seats 9.1. While the straightening machine upper roller 8.1 rotates, the straightening machine lower roller 12.1 is driven to rotate between two straightening machine lower roller bearing seats 13.1 through the casting 11.1;

[0037] Step 2: The upper roller 8.1 of the straightening machine controls the first straightening machine servo hydraulic cylinder 2.1, the second straightening machine servo hydraulic cylinder 2.2 and the balance cylinder 6.1 through the heavy pressure of the billet continuous casting machine, and then controls the roll gap position formed by the upper roller 8.1 of the straightening machine and the lower roller 12.1 of the straightening machine;

[0038] Step 3: The rod cavity of the balance cylinder 6.1 is connected to the pressure oil P1 reduced by the three-way pressure reducing valve 5.1, and a bladder accumulator 7.1 is arranged behind the three-way pressure reducing valve to stabilize the pressure reduction. By adjusting the P1 pressure, the upper roller bearing seat 9.1 of the upper roller 8.1 of the straightening machine is always in close contact with the piston rod mushroom head of the first straightening machine servo hydraulic cylinder 2.1 and the second straightening machine servo hydraulic cylinder 2.2, so as to prevent the deflection of the upper roller 8.1 of the straightening machine caused by the straightening machine transmission mechanism 10.1, and prevent the first straightening machine servo hydraulic cylinder 2.1 and the second straightening machine servo hydraulic cylinder 2.2 from bearing lateral force;

[0039] Step 4: The pressure is controlled by the first pressure sensor 4.1, the second pressure sensor 4.2, the third pressure sensor 4.3 and the fourth pressure sensor 4.4 respectively connected to the plug cavity and the rod cavity of the first straightening machine servo hydraulic cylinder 2.1 and the second straightening machine servo hydraulic cylinder 2.2. The first displacement sensor 3.1 and the second displacement sensor 3.2 in the first straightening machine servo hydraulic cylinder 2.1 and the second straightening machine servo hydraulic cylinder 2.2 are used to monitor the positions of the telescopic rods in the first straightening machine servo hydraulic cylinder 2.1 and the second straightening machine servo hydraulic cylinder 2.2.

[0040] Through the above method, the heavy pressure straightening machine adopts two proportional directional valves to control two straightening machine servo hydraulic cylinders and forms a position closed loop through displacement sensors. The displacement compensation of equipment gap and equipment elastic deformation is realized through pressure sensors, and finally the precise control of the roll gap position composed of the upper roller and the lower roller of the straightening machine is realized. The rod cavity of the balance cylinder 6.1 is connected to the pressure oil P1 reduced by the three-way pressure reducing valve 5.1, and a bladder accumulator 7.1 is provided to stabilize the reduced pressure pressure. By adjusting the appropriate P1 pressure, the bearing seat of the upper roller of the straightening machine is always in close contact with the mushroom head of the piston rod of the servo hydraulic cylinder of the straightening machine, which can prevent the deflection of the upper roller of the straightening machine caused by the deadweight of the transmission mechanism of the straightening machine, and can prevent the servo hydraulic cylinder of the straightening machine from being subjected to lateral force, thereby improving the reliability and service life of the hydraulic cylinder of the straightening machine.

[0041] The above is a detailed description of the embodiments of the present invention in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Within the knowledge scope of ordinary technicians in the field, various changes can be made without departing from the purpose of the present invention, which are all within the protection scope of this technology.

[0042] It should be noted that all directional indications in the embodiments of the present invention, such as up, down, left, right, front, back, etc., are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0043] The technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that they can be implemented by ordinary technicians in the field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

Claims

1. A billet continuous casting machine under heavy pressure straightening machine, comprising at least a straightening machine frame, characterized in that: The top of the inner side of the straightening machine frame is connected to the hydraulic control system of the straightening machine under the heavy pressure of the billet continuous casting machine, the bottom of the inner side of the straightening machine frame is connected to two lower roller bearing seats (13.1) of the straightening machine, a lower roller (12.1) of the straightening machine is connected between the two lower roller bearing seats (13.1), the top of the lower roller (12.1) of the straightening machine is connected to the upper roller (8.1) of the straightening machine through the casting billet (11.1), the upper roller (8.1) of the straightening machine is connected to the middle position of the inner side of the straightening machine frame through two upper roller bearing seats (9.1), the upper roller (8.1) of the straightening machine is controlled by the hydraulic control system of the straightening machine under the heavy pressure of the billet continuous casting machine, the tops of the two upper roller bearing seats (9.1) of the straightening machine are also connected by a crossbeam, the two upper roller bearing seats (9.1) of the straightening machine are fixed to the straightening machine frame by bolts, and one end of the upper roller (8.1) of the straightening machine is also connected to the straightening machine transmission mechanism (10.1); The hydraulic control system of the heavy-pressure straightening machine of the square billet continuous casting machine comprises a proportional directional valve, a straightening machine servo hydraulic cylinder, a three-way pressure reducing valve (5.1), a balancing cylinder (6.1), a bladder-type accumulator (7.1) and a PLC control unit. The tail of the straightening machine servo hydraulic cylinder is connected to the top of the inner side of the straightening machine frame through a flange. The piston rod end of the straightening machine servo hydraulic cylinder is a mushroom head type. The piston rod end of the straightening machine servo hydraulic cylinder contacts the top of the upper roller bearing seat (9.1) of the straightening machine through the mushroom head. One end of the balancing cylinder (6.1) is hinged to the top of the inner side of the straightening machine frame, and the other end of the balancing cylinder (6.1) is hinged to the inner side of the straightening machine frame. The middle part of the crossbeam between the tops of the two upper roller bearing seats (9.1) of the straightening machines is hinged, one end of the proportional directional valve and the three-way pressure reducing valve (5.1) are connected to the hydraulic system pressure oil supply port P and the hydraulic system return oil port T of the hydraulic system through oil pipelines, the other end of the proportional directional valve is connected to the straightening machine servo hydraulic cylinder through the oil pipeline, the other end of the three-way pressure reducing valve (5.1) is connected to the balance cylinder (6.1) and the bladder accumulator (7.1) through the oil pipeline, one end of the three-way pressure reducing valve (5.1) is also connected to the hydraulic system leakage oil port L through the oil pipeline, and the PLC control unit is used to control the straightening machine servo hydraulic cylinder.

2. The heavy pressure straightening machine for a billet continuous casting machine according to claim 1, characterized in that: The proportional directional valve and the straightening machine servo hydraulic cylinder are both provided with two groups, the proportional directional valve comprises a first proportional directional valve (1.1) and a second proportional directional valve (1.2), the straightening machine servo hydraulic cylinder comprises a first straightening machine servo hydraulic cylinder (2.1) and a second straightening machine servo hydraulic cylinder (2.2), the tails of the first straightening machine servo hydraulic cylinder (2.1) and the second straightening machine servo hydraulic cylinder (2.2) are connected to the top of the inner side of the straightening machine frame through a flange, the piston rod ends of the first straightening machine servo hydraulic cylinder (2.1) and the second straightening machine servo hydraulic cylinder (2.2) are mushroom head type, and the first straightening machine servo hydraulic cylinder (2.1) and the second straightening machine servo hydraulic cylinder (2.2) are The piston rod ends of the hydraulic cylinder (2.1) and the second straightening machine servo hydraulic cylinder (2.2) are in contact with the tops of the two straightening machine upper roller bearing seats (9.1) through mushroom heads; one end of the first proportional directional valve (1.1) and the second proportional directional valve (1.2) are connected to the hydraulic system pressure oil supply port P and the hydraulic system return oil port T of the hydraulic system through oil pipelines, respectively; the other end of the first proportional directional valve (1.1) is connected to the first straightening machine servo hydraulic cylinder (2.1) through the oil pipeline; and the other end of the second proportional directional valve (1.2) is connected to the second straightening machine servo hydraulic cylinder (2.2) through the oil pipeline.

3. The heavy pressure straightening machine for a square billet continuous casting machine according to claim 2, characterized in that: Pressure sensors are connected to the oil pipeline connecting the first proportional directional valve (1.1) and the first straightening machine servo hydraulic cylinder (2.1) and the oil pipeline connecting the second proportional directional valve (1.2) and the second straightening machine servo hydraulic cylinder (2.2), and displacement sensors are provided in the straightening machine servo hydraulic cylinder (2.1) and the second straightening machine servo hydraulic cylinder (2.2).

4. The heavy pressure straightening machine for a square billet continuous casting machine according to claim 3, characterized in that: The pressure sensor comprises a first pressure sensor (4.1), a second pressure sensor (4.2), a third pressure sensor (4.3) and a fourth pressure sensor (4.4); the first pressure sensor (4.1) and the second pressure sensor (4.2) are connected to an oil pipeline connecting a first proportional directional valve (1.1) and a first straightening machine servo hydraulic cylinder (2.1); the third pressure sensor (4.3) and the fourth pressure sensor (4.4) are connected to an oil pipeline connecting a second proportional directional valve (1.2) and a second straightening machine servo hydraulic cylinder (2.2); the displacement sensor comprises a first displacement sensor (3.1) and a second displacement sensor (3.2); the first displacement sensor (3.1) is connected to the first straightening machine servo hydraulic cylinder (2.1); and the second displacement sensor (3.2) is connected to the second straightening machine servo hydraulic cylinder (2.2).

5. The heavy pressure straightening machine for a square billet continuous casting machine according to claim 1, characterized in that: The straightening machine transmission mechanism (10.1) is composed of a motor and a reducer.

6. A hydraulic control method for a heavy pressure straightening machine for a billet continuous casting machine comprises the heavy pressure straightening machine for a billet continuous casting machine as claimed in claim 4, characterized in that: The following steps are involved: Step 1: The straightening machine transmission mechanism (10.1) drives the straightening machine upper roller (8.1) to rotate between two straightening machine upper roller bearing seats (9.1), and while the straightening machine upper roller (8.1) rotates, the straightening machine lower roller (12.1) is driven to rotate between two straightening machine lower roller bearing seats (13.1) through the ingot (11.1); Step 2: The upper roller (8.1) of the straightening machine controls the first straightening machine servo hydraulic cylinder (2.1), the second straightening machine servo hydraulic cylinder (2.2) and the balance cylinder (6.1) through the heavy pressure of the billet continuous casting machine, thereby controlling the roller gap position formed by the upper roller (8.1) of the straightening machine and the lower roller (12.1) of the straightening machine; Step 3: The rod chamber of the balance cylinder (6.1) is connected to the pressure oil P1 reduced by the three-way pressure reducing valve (5.1), and a bladder accumulator (7.1) is arranged behind the three-way pressure reducing valve to stabilize the reduced pressure. By adjusting the P1 pressure, the upper roller bearing seat (9.1) of the upper roller (8.1) of the straightening machine is always in close contact with the piston rod mushroom head of the first straightening machine servo hydraulic cylinder (2.1) and the second straightening machine servo hydraulic cylinder (2.2), so as to prevent the upper roller (8.1) of the straightening machine from being deflected by the straightening machine transmission mechanism (10.1) and to prevent the first straightening machine servo hydraulic cylinder (2.1) and the second straightening machine servo hydraulic cylinder (2.2) from being subjected to lateral force; Step 4: The pressure is controlled by the first pressure sensor (4.1), the second pressure sensor (4.2), the third pressure sensor (4.3) and the fourth pressure sensor (4.4) respectively connected to the plug cavity and the rod cavity of the first straightening machine servo hydraulic cylinder (2.1) and the second straightening machine servo hydraulic cylinder (2.2), and the first displacement sensor (3.1) and the second displacement sensor (3.2) in the first straightening machine servo hydraulic cylinder (2.1) and the second straightening machine servo hydraulic cylinder (2.2) are used to monitor the position of the telescopic rod in the first straightening machine servo hydraulic cylinder (2.1) and the second straightening machine servo hydraulic cylinder (2.2).

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