CN110594210A - Hydraulic control system for press roll of withdrawal and straightening machine based on position and pressure double-control mode - Google Patents

Abstract

The invention discloses a hydraulic control system for the pressing roll of a tension leveler based on a position and pressure dual control mode, which realizes dual control of the position and pressure of the tension leveler in three working states through a set of servo valves, and pinches dummy ingots In working conditions and conventional hot casting slab production conditions, the pressure closed-loop circuit is adopted as the main mode and the position auxiliary control method is adopted. In the production condition of light reduction, the position closed-loop control is adopted as the main method, and the pressure auxiliary control method is adopted to control the servo valve to accurately control the pressing position of the pressing roller of the tension leveling machine. The hydraulic circuit is simple and reliable, and it is completely suitable for the hydraulic control of the pressure roll of the tension leveler of the continuous casting machine equipped with the light reduction function. When there is a component failure in the servo valve, pressure sensor or displacement sensor, it will not affect the production continuity of the continuous casting machine. The hydraulic control system of the double control mode can also be used for judging the end position of the slab solidification.

Description

The hydraulic control system of the pressing roll of the tension leveler based on the dual control mode of position and pressure

technical field

The invention belongs to the technical field of hydraulic control of continuous casting machines in the metallurgical industry, and relates to a hydraulic control system for pressing rollers of a tensioning and leveling machine based on a dual control mode of position and pressure, which is suitable for continuous casting machines equipped with a light pressing function.

Background technique

In the production process of the continuous casting machine equipped with soft reduction function, there are usually working conditions of pinch dummy, conventional hot casting slab production and light reduction production conditions. For pinching dummy rods and hot casting slabs, this hydraulic cylinder also provides light reduction control. In the working condition of pinching the dummy bar and the normal hot casting slab production condition, the hydraulic control system of the pressing roller of the tension leveling machine performs pressure control, and in the production condition of light reduction, the position closed-loop control of the pressing roller of the tensioning and straightening machine , Therefore, the hydraulic control system of the pressing roll of the tension leveler needs to be configured with two sets of pressure control loop and position closed loop control loop, and the configuration of hydraulic system components is complicated.

In practical application, it is found that during the working process of the pressure control circuit, the pressing position of the pressing roll of the tension leveling machine cannot be controlled. When the pressure regulating element has a pressure failure, it will easily lead to the interruption of the continuous casting machine production. When implementing the position closed-loop control loop, due to the influence of factors such as roll gap calibration, the mechanical gap of the lower roller of the tension leveler and the thermal deformation of the frame, the position detection cannot truly reflect the actual roll gap of the lower roller of the tension leveler. The position closed-loop control will cause deviation in the roll gap control; when the reduction of the lower roll of the tension leveling and pressing is too large and the actual roll gap is too small, the drawing resistance will increase, and the wear of the pressing roll of the tensioning and leveling machine will increase, and the tension will be affected. The damage to the machine equipment may even cause the slab to stagnate or cause cracks inside the slab. When the rolling pressure drop of the tension leveler is too small and the actual roll gap is too large, the metallurgical effect of the light reduction function cannot be realized. In severe cases, the driving roll of the tension leveler cannot output sufficient drawing force, and casting The phenomenon of billet slipping or sliding billet will affect the normal production of the continuous casting machine.

Contents of the invention

In order to overcome the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to provide a hydraulic control system for the pressing roll of the tensioning and leveling machine based on the dual control mode of position and pressure, which realizes the pinching and guiding only through a set of servo valves. Position and pressure control under the three working conditions of ingot rod working condition, conventional hot casting slab production working condition and light reduction production working condition, avoiding the complicated hydraulic pipeline with two sets of pressure control loop and position closed loop control loop configured at the same time It can also realize the position control of the reduction when the servo valve, pressure sensor or displacement sensor fails, and can realize the light reduction function even when the reduction of the reduction roller of the tension leveler is too small and the actual roll gap is too large. It is completely suitable for the hydraulic control of the pressure roll of the tension leveler of the continuous casting machine with the soft reduction function.

In order to solve the problems of the technologies described above, the present invention adopts the following technical solutions:

A hydraulic control system for the pressing roll of the tensioning and leveling machine based on the dual control mode of position and pressure, the hydraulic cylinder (15) of the tensioning and leveling machine is power-connected with the pressing roll (16) of the tensioning and leveling machine, and is characterized in that:

The hydraulic cylinder (15) is provided with a built-in position sensor (14) to detect the position of the hydraulic cylinder in real-time; The internal hydraulic pipeline is connected to form a position and pressure dual control mode circuit; when the dummy ingot is pinched and the conventional hot casting slab is produced, the pressure closed-loop circuit is used as the main mode and the position auxiliary control mode is adopted, and the servo valve is controlled according to different Stable dummy pressure Pd and hot billet pressure Ph are output under the working condition; in the production condition under light pressure, the position closed-loop control is adopted as the main mode, and the pressure auxiliary control method is adopted to control the servo valve to accurately control the pressure of the pressing roller of the tensioning and leveling machine. next position.

Further, the servo valve group mainly includes a servo valve (7), a first hydraulic control check valve (801), a second hydraulic control check valve (802), and a two-position four-way electromagnetic reversing valve (5); The servo valve (7) has a safety position function, and the safety position is "y" type. The lifting and pressing position, lifting speed and pressing speed of the pressing roller (16) are controlled by the servo valve (7), as well as the hydraulic pressure. The pressure of the two chambers of the cylinder (15); the first hydraulically controlled check valve (801) and the second hydraulically controlled check valve (802) are used for the one-way flow of the hydraulic oil in the A pipeline and the B pipeline at the outlet of the servo valve (7). direction isolation; when the electromagnet a of the two-position four-way electromagnetic reversing valve (5) is energized, the first hydraulic control check valve (801) and the second hydraulic control check valve (802) are opened;

The accident pressure control circuit mainly includes a pressure reducing valve (3), a two-position two-way cut-off directional valve (4), and a third one-way valve (203); the oil port B of the pressure reducing valve (3) passes through the first ball valve (101) is connected to the pressure oil source PE of the accumulator, and the oil port A of the pressure reducing valve (3) is connected to the oil port P1 of the two-position two-way cut-off directional valve (4); the two-position two-way cut-off directional valve ( 4) The oil port T is connected to the oil port A of the third check valve (203) and connected to the outlet pipeline of the oil port B of the first hydraulic control check valve (801) through the third check valve (203); The third one-way valve (203) is used for one-way isolation of the emergency pressure control circuit and the oil port A outlet pipeline of the servo valve (7);

The pressure sensor group mainly includes a first pressure sensor (1201) and a second pressure sensor (1202), the first pressure sensor (1201) detects the pressure value of the rodless chamber pipeline of the hydraulic cylinder (15) in real time, and the second pressure sensor (1202) Real-time detection of the pressure value of the rod chamber pipeline of the hydraulic cylinder (15);

The high-pressure filter group filters the hydraulic oil entering and returning the servo valve (7) to protect the servo valve (7), and mainly includes a high-pressure filter (6), a first high-pressure one-way filter (1101) and the second high-pressure one-way filter (1102); the high-pressure filter (6) is set on the P port of the servo valve (7), and the first high-pressure one-way filter (1101) is set on the pipeline of the A port of the servo valve (7) , the second high-pressure one-way filter (1102) is set on the B-port pipeline of the servo valve (7);

The online flushing circuit mainly includes a two-position three-way ball valve (10) and a fifth ball valve (105) arranged on the hydraulic cylinder (15); the oil port A of the two-position three-way ball valve (10) is connected to the second high-pressure one-way The filter (1102) is connected, the oil port B of the two-position three-way ball valve (10) is connected to the oil port B of the second hydraulic control check valve (802), and the oil port C of the two-position three-way ball valve (10) It is connected with the oil return pipeline T to realize the online flushing of the A pipeline and the B pipeline at the outlet of the servo valve (7).

Furthermore, the P port of the servo valve (7) is connected to the pressure oil source P of the hydraulic system through the high pressure filter (6) and the second ball valve (102), and the T port of the servo valve (7) is connected to the second one-way valve (202 ) is connected to the oil port A of the second check valve (202) and the oil return line T; the A port of the servo valve (7) is connected to the oil port A of the first hydraulic control check valve (801), and the servo valve (7) Port B is connected to oil port A of the second hydraulic control check valve (802);

The oil port X of the first hydraulic control check valve (801) is connected to the oil port B of the two-position four-way electromagnetic reversing valve (5), and the oil port L of the first hydraulic control check valve (801) is connected to the first single Connect to the oil port A of the valve (201) and connect to the drain line L through the first one-way valve (201);

The oil port A of the second hydraulic control check valve (802) is connected to the oil port B of the servo valve (7), and the oil port X of the second hydraulic control check valve (802) is connected to the port X of the two-position four-way electromagnetic reversing valve. The oil port B is connected, and the oil port L of the second hydraulic control check valve (802) is connected with the oil port A of the first check valve (201) and connected with the drain line L through the first check valve (201);

The oil port P of the two-position four-way electromagnetic reversing valve (5) is connected to the pressure oil source P through the second ball valve (102), and the oil port T of the two-position four-way electromagnetic reversing valve (5) is connected to the first check valve The oil port A of (201) is connected with the oil drain line L through the first one-way valve (201).

The oil port A of the second check valve (202) is connected to the oil port T of the servo valve (7), the oil port B of the second check valve (202) is connected to the oil return line T, and the second check valve (202) is used It is used to isolate the return oil of the servo valve (7) and the oil return line T, and provide back pressure for the oil return to the servo valve (7); the oil port A of the fourth check valve (204) is connected to the oil return line T, and the oil return line T of the fourth check valve (204) The oil port B of the four check valves (204) is connected to the outlet pipeline of the oil port B of the second hydraulic control check valve (802); the fourth check valve (204) is used to supplement the rod cavity of the hydraulic cylinder (15). Oil control prevents hydraulic cylinder (15) from sucking air in the rod cavity, causing damage to the seal of the hydraulic cylinder.

Further, a relief valve (9) is also provided, the P port of the relief valve (9) is connected to the oil port B outlet pipeline of the first hydraulic control check valve (801), and the T port of the relief valve (9) Connect the oil return line T; the overflow valve (9) is used for the overpressure protection of the rodless chamber of the hydraulic cylinder (15) to prevent the pressure of the rodless chamber of the hydraulic cylinder (15) from being too large, causing the rodless chamber of the hydraulic cylinder (15) to seal damage, while preventing equipment damage due to external loads.

Further, the accident pressure control circuit is also provided with a pressure measuring joint M for pressure measurement of the circuit; in an accident state, the electromagnet a of the two-position two-way cut-off directional valve (4) is energized, and the accident pressure control circuit automatically work; the pressure oil source PE of the accumulator is decompressed to a suitable accident pressure through the pressure reducing valve (3), and enters the hydraulic cylinder (15 ) rodless cavity, the pressing roller (16) implements the pressing control on the cast slab with the accident pressure.

Furthermore, one end of the first pressure sensor (1201) is connected to the first high-pressure one-way filter (1101) through the third ball valve (103), and the other end is connected to the rodless chamber A of the hydraulic cylinder (15) through a hose (1301). connected to detect the pressure value of the rodless chamber pipeline in real time; one end of the second pressure sensor (1202) is connected to the second high-pressure one-way filter (1102) through the fourth ball valve (104), and the other end is connected to the second high-pressure one-way filter (1102) through another hose (1302 ) is connected with the rod chamber B of the hydraulic cylinder (15) to detect the pressure value of the rod chamber pipeline in real time.

Further, one end of the high-pressure filter (6) is connected to the pressure oil source P through the second ball valve (102), and the other end is connected to the oil port P of the servo valve (7), which is used to open and close the pressure oil source to enter the servo valve ( 7); One end of the first high-pressure one-way filter (1101) is connected to the B-port pipeline of the first hydraulically controlled one-way valve (801), and the other end is connected to the hydraulic pressure through the third ball valve (103) and a hose (1301). The rodless chamber A of the cylinder is connected; one end of the second high-pressure one-way filter (1102) is connected to the B-port pipeline of the second hydraulic control check valve (802), and the other end passes through the ball valve (104), another hose ( 1302) is connected with the rod cavity B of the hydraulic cylinder.

Further, when the two-position three-way ball valve (10) is in the working state, the oil port A is connected to the oil port B, and in the online flushing state, the oil port A is connected to the oil port C; the fifth ball valve (105) is in the hydraulic cylinder (15 ) is closed during operation and opened during line flushing.

Further, the built-in position sensor (14) has a protective cover and is protected by cooling air.

Further, in the working condition of pinching dummy ingot and conventional hot casting slab production working condition, the electromagnet a of the two-position four-way electromagnetic reversing valve (5) is energized to control the opening of the first hydraulic control check valve (801) and the second hydraulic control check valve (802). In this state, the servo valve (7) controls the lifting and pressing of the pressing roller (16). When the pressing roller (16) is pressing down, the hydraulic pressure The value of the pressure sensor in the cylinder (15) without the rod chamber and the rod chamber, automatically controls the opening of the servo valve (7) to realize the closed-loop control of the pressure in the two chambers of the hydraulic cylinder, and outputs stable dummy pressure Pd according to different working conditions and the hot billet pressure Ph; by detecting the value of the displacement sensor on the hydraulic cylinder, position auxiliary control is introduced. When the displacement value is within the position range given by the process, the pressure closed-loop control is effective. When the displacement value exceeds the position range given by the process , the pressure closed-loop control fails, and enters the position control protection mode;

Under light pressure production conditions, the electromagnet a of the two-position four-way electromagnetic reversing valve (5) is energized to control the opening of the first hydraulic control check valve (801) and the second hydraulic control check valve (802) , the servo valve (7) controls the lifting and pressing position of the pressing roller (16), the lifting speed and the pressing speed; by detecting the value of the displacement sensor on the hydraulic cylinder, the servo valve (7) is automatically controlled to realize the The closed-loop control of the position of the hydraulic cylinder (15) accurately controls the pressing amount of the pressing roller (16); on the basis of position control, by detecting the values of the pressure sensors in the rodless chamber and the rod chamber of the hydraulic cylinder (15), The pressure auxiliary control is introduced. When the pressure value is within the position range given by the process, the position closed-loop control is valid. When the pressure value exceeds the pressure range given by the process, the position closed-loop control is invalid and it is transferred to the pressure control protection mode.

Furthermore, when the servo valve (7), the pressure sensor or the displacement sensor has component failure, the electric automatic control servo valve (7) is placed in the safe position "Y" type, and the solenoid of the two-position four-way electromagnetic reversing valve (5) Iron a is de-energized; in this state, the electromagnet a of the two-position two-way cut-off directional valve (4) is energized, and the emergency depressing circuit automatically works; the emergency oil source PE passes through the pressure reducing valve (3), two-position two-way The cut-off directional valve (4) and the third check valve (203) enter the rodless cavity of the hydraulic cylinder (15), and the pressing roller (16) implements the pressing control of the billet with the accident pressure without affecting the continuous casting machine. production continuity.

Further, when the tension leveling frame, hydraulic hoses are replaced or secondary pollution is caused to the hydraulic pipeline due to maintenance work, the fifth ball valve (105) and the two-position three-way ball valve (10 ) oil port A is connected to oil port C; in this state, the electromagnet a of the two-position two-way cut-off directional valve (4) is energized, and the pressure oil passes through the pressure reducing valve (3), two-position two-way cut-off type Directional valve (4), the first high-pressure one-way filter (1101), the fifth ball valve (105), the second high-pressure one-way filter (1102), and the oil port C of the two-position three-way ball valve (10) are connected to the return The oil pipeline T forms an online flushing return oil. The in-line flushing circuit does not pass through the servo valve (7).

Working principle of the present invention:

During the working conditions of pinching dummy ingots and conventional hot casting slab production conditions, by detecting the values of the pressure sensors in the rodless cavity and the rod cavity of the hydraulic cylinder, the electric automatic control servo valve realizes the closed-loop pressure control in the hydraulic cylinder cavity, according to Output stable dummy pressure Pd and hot billet pressure Ph under different working conditions; furthermore, by detecting the value of the displacement sensor on the hydraulic cylinder, position auxiliary control is introduced. When the displacement value is within the position range given by the process, the pressure The closed-loop control is valid. When the displacement value exceeds the position range given by the process, the pressure closed-loop control will fail, and it will enter the position control protection mode.

In the light production condition, the servo valve (7) controls the lifting and pressing position, lifting speed and pressing speed of the pressing roller (16); by detecting the value of the displacement sensor on the hydraulic cylinder, the electrical The servo valve is automatically controlled to realize the closed-loop control of the position of the hydraulic cylinder, and accurately control the pressing position of the hydraulic cylinder of the tension leveling machine; further, by detecting the value of the pressure sensor in the rodless cavity and the rod cavity of the hydraulic cylinder, the pressure assist is introduced. Control, when the pressure value is within the position range given by the process, the position closed-loop control is valid, when the pressure value exceeds the pressure range given by the process, the position closed-loop control is invalid, and it turns into the pressure control protection mode.

When the servo valve, pressure sensor or displacement sensor has a component failure, the electric automatic control servo valve is placed in a safe position, the electromagnet a of the two-position two-way cut-off directional valve is energized, and the emergency depressing circuit automatically works. The accident oil source PE enters the rodless cavity of the hydraulic cylinder through the pressure reducing valve, the two-position two-way cut-off directional valve, and the one-way valve. production continuity.

Beneficial effect:

Through a set of servo valves, the present invention realizes dual control of the position and pressure of the hydraulic cylinder of the stretching and leveling machine in three working states, and controls the lifting and pressing positions, lifting speed and pressing speed of the pressing roller of the tensioning and straightening machine , It can also control the pressure in the hydraulic cylinder cavity of the tension leveler, so as to achieve the purpose of dual control of the pressing position of the pressing roller of the tension leveler and the pressure in the hydraulic cylinder cavity of the tension leveler. In pinching dummy conditions and conventional hot slab production conditions, the pressure closed-loop circuit is adopted as the main mode, and the position auxiliary control method is adopted to control the servo valve to output stable dummy pressure Pd and hot slab pressure Ph according to different working conditions. In the production condition of light reduction, the position closed-loop control is adopted as the main method, and the pressure auxiliary control method is adopted to control the servo valve to accurately control the pressing position of the pressing roller of the tension leveling machine.

The hydraulic circuit is simple and reliable, and has the advantages of high control precision and high degree of automation. It is completely suitable for the hydraulic control of the pressure roll of the tension leveler of the continuous casting machine equipped with light reduction function.

When the servo valve, pressure sensor or displacement sensor fails, the electrical automatic control of the servo valve will make the pressing roller of the tensioning and leveling machine carry out the pressing control of the billet with the accident pressure, without affecting the production continuity of the continuous casting machine.

In addition, the dual-control hydraulic control system can also be used to judge the position of the solidification end of the slab. On the premise of the position closed-loop auxiliary control, the high-precision pressure closed-loop control can reflect the stress state of the slab in real time. According to the force state Determine the position of the solid-liquid two-phase region, and provide accurate feedback data for the application of dynamic soft reduction technology.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings.

Fig. 1 is a schematic diagram of the hydraulic control system of the pressing roll of the tension leveler based on the dual control mode of position and pressure.

The reference signs in the figure are: ball valve (101/102/103/104/105), one-way valve (201/202/203/204), pressure reducing valve 3, two-position two-way cut-off directional valve 4, two-way 4-position electromagnetic reversing valve 5, high-pressure filter 6, servo valve 7, hydraulic control check valve (801/802), overflow valve 9, two-position three-way ball valve 10, high-pressure one-way filter (1101/1102 ), pressure sensor (1201/1202), hose (1301/1302), built-in displacement sensor 14, hydraulic cylinder 15, and pressing roller 16.

Detailed ways

The present invention will be further described in detail below in conjunction with accompanying drawing 1 and embodiments.

According to the present invention, the hydraulic control system of the press roll of the tensioning and leveling machine based on the dual control mode of position and pressure is as shown in Figure 1, which includes a servo valve group, an emergency pressure control circuit, a pressure sensor group, a high-pressure filter, and an online flushing circuit. And a hydraulic cylinder 15 with a built-in position sensor. A continuous casting machine with soft reduction function is usually equipped with multiple tension levelers, and the present invention only uses one tension leveler as an example for illustration.

The servo valve group consists of servo valve 7, hydraulic control check valve (801/802), two-position four-way electromagnetic reversing valve 5, ball valve 102, check valve (202/204), overflow valve 9 and pressure measuring Joint M composition. The P port of the servo valve 7 is connected to the pressure oil source P of the hydraulic system through the high pressure filter 6 and the ball valve 102, and the T port of the servo valve 7 is connected to the oil port A of the one-way valve 202 and connected to the oil return line T through the one-way valve 202 Connection; port A of servo valve 7 is connected to oil port A of hydraulic control check valve 801, and port B of servo valve 7 is connected to oil port A of hydraulic control check valve 802; through servo valve 7, the pressure of tension straightening machine is controlled. The lifting and pressing positions of the lower roller 16, the lifting speed and the pressing speed can also control the pressure of the two chambers of the hydraulic cylinder 15 of the tension leveler. The servo valve 7 has a safety position function, and the safety position is "y" type. The oil port A of the hydraulic control check valve 801 is connected to the oil port A of the servo valve 7, and the oil port X of the hydraulic control check valve 801 is connected to the oil port B of the two-position four-way electromagnetic reversing valve 5. The oil port L of the valve 801 is connected with the oil port A of the one-way valve 201 and connected with the oil drain line L through the one-way valve 201 . The oil port A of the hydraulic control check valve 802 is connected to the oil port B of the servo valve 7, the oil port X of the hydraulic control check valve 802 is connected to the oil port B of the two-position four-way electromagnetic reversing valve, and the hydraulic control check valve The oil port L of 802 is connected with the oil port A of the one-way valve 201 and connected with the oil drain line L through the one-way valve 201 . The two hydraulically controlled one-way valves 801 and 802 are used for one-way isolation of the hydraulic oil in the A pipeline and the B pipeline at the outlet of the servo valve 7 . The oil port P of the two-position four-way electromagnetic reversing valve 5 is connected to the pressure oil source P through the ball valve 102, and the oil port T of the two-position four-way electromagnetic reversing valve 5 is connected to the oil port A of the check valve 201 and passed through the check valve. 201 is connected with the drain pipeline L. When the electromagnet a of the two-position four-way electromagnetic reversing valve 5 is energized, the hydraulic control check valve (801/802) is opened. The ball valve 102 is connected with the pressure oil source P for opening and closing the pressure oil source entering the servo valve 7 . The oil port A of the check valve 202 is connected to the oil port T of the servo valve 7, the oil port B of the check valve 202 is connected to the oil return line T, and the check valve 202 is used for one-way isolation of the oil return line of the servo valve 7 and the oil return line T, and provide a certain oil return back pressure to the servo valve 7. The oil port A of the check valve 204 is connected to the oil return line T, and the oil port B of the check valve 204 is connected to the outlet line of the oil port B of the hydraulic control check valve 802; Oil replenishment control prevents the hydraulic cylinder 15 from being sucked out of the rod cavity, causing the seal of the hydraulic cylinder 15 to be damaged. The P port of the overflow valve 9 is connected to the oil port B outlet pipeline of the hydraulic control check valve 801, and the T port of the overflow valve 9 is connected to the oil return line T; the overflow valve 9 is used for overpressure protection of the rodless chamber of the hydraulic cylinder , to prevent excessive pressure in the rodless chamber of the hydraulic cylinder 15, causing damage to the seal of the rodless chamber of the hydraulic cylinder 15, and at the same time prevent equipment damage due to external loads. The pressure measuring connection M is used for the pressure measurement of the corresponding circuit.

The emergency pressure control loop is composed of a ball valve 101, a pressure reducing valve 3, a two-position two-way cut-off directional valve 4, a one-way valve 203 and a pressure measuring joint M. The oil port B of the pressure reducing valve 3 is connected to the accumulator pressure oil source PE through the ball valve 101, and the oil port A of the pressure reducing valve is connected to the oil port P1 of the two-position two-way cut-off directional valve 4; the two-position two-way cut-off type The oil port T of the directional valve 4 is connected with the oil port A of the check valve and connected with the oil port B outlet pipeline of the hydraulic control check valve 801 through the check valve 203 . The one-way valve 203 is used for one-way isolating the emergency pressure pipeline and the oil port A outlet pipeline of the servo valve 7 . In an accident state, the electromagnet a of the two-position two-way cut-off directional valve 4 is energized, and the emergency depressing circuit works automatically. The pressure oil source PE of the accumulator is decompressed by the pressure reducing valve 3 to a suitable accident pressure, and enters the rodless chamber of the hydraulic cylinder 15 through the two-position two-way cut-off directional valve 4 and the one-way valve 203, and the pulling and leveling machine presses down the roller 16. Carry out the reduction control on the slab with the accident pressure.

The pressure sensor group is composed of a pressure sensor 1201 and a pressure sensor 1202; one end of the pressure sensor 1201 is connected to the high-pressure one-way filter 1101 through the ball valve 103, and the other end is connected to the rodless chamber A of the hydraulic cylinder 15 through the hose 1301 to detect the rodless pressure in real time. The pressure value of the lumen line. One end of the pressure sensor 1202 is connected to the high-pressure one-way filter 1102 through the ball valve 104, and the other end is connected to the rod chamber B of the hydraulic cylinder 15 through the hose 1302 to detect the pressure value of the pipe in the rod chamber in real time.

The high-pressure filter group is composed of a high-pressure filter 6, a high-pressure one-way filter 1101 and a high-pressure one-way filter 1102; the high-pressure filter 6 is arranged at the P port of the servo valve, and one end is connected to the pressure oil source P through a ball valve 102, One end is connected to the oil port P of the servo valve 7; the high-pressure one-way filter 1101 is set on the A-port pipeline of the servo valve 7, one end is connected to the B-port pipeline of the hydraulic control check valve 801, and the other end passes through the ball valve 103, the hose 1301 is connected to the rodless chamber A of the hydraulic cylinder; the high-pressure one-way filter 1102 is set on the B-port pipeline of the servo valve 7, one end is connected to the B-port pipeline of the hydraulic control one-way valve 802, and the other end passes through the ball valve 104, the hose 1302 is connected with the rod chamber B of the hydraulic cylinder. Three high-pressure filters filter the hydraulic oil entering and returning to the servo valve 7 to protect the servo valve 7.

The online flushing circuit is composed of a two-position three-way ball valve 10 and a ball valve 105, which can realize online flushing of the outlet A pipeline and the outlet B pipeline of the servo valve 7. The oil port A of the two-position three-way ball valve 10 is connected to the high-pressure one-way filter 1102, the oil port B of the two-position three-way ball valve 10 is connected to the oil port B of the hydraulic control check valve 802, and the two-position three-way ball valve 10 The oil port C is connected to the oil return line T. When the two-position three-way ball valve 10 is in the working state, the oil port A is connected to the oil port B, and in the online flushing state, the oil port A is connected to the oil port C. The ball valve 105 is arranged on the hydraulic cylinder 15 of the stretching and straightening machine, which is closed during work and opened during online flushing.

The hydraulic cylinder with a built-in displacement sensor is composed of a built-in displacement sensor 14 , a hydraulic cylinder 15 and a pressing roller 16 . The built-in displacement sensor 14 detects the position of the hydraulic cylinder 15 in real time, and the built-in position sensor 14 is attached with a protective cover, and is protected by cooling air.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any form. Any simple modifications made to the above embodiment according to the technical essence of the present invention are equivalent to changes and modifications. All belong to the scope of the technical solution of the present invention.

Below in conjunction with three kinds of working states and each loop action principle situation, the working process of the present invention is illustrated:

(1) Pinch dummy spindle working condition

In the working condition of pinching the dummy, the electromagnet a of the two-position four-way electromagnetic reversing valve 5 is energized to control the opening of the hydraulic control check valves 801 and 802. In this state, the servo valve 7 controls the tension leveler to press down Lifting and pressing of roller 16. When the pressing roller 16 is pressed down, by detecting the value of the pressure sensor in the rodless cavity and the rod cavity of the hydraulic cylinder 15, the electric automatic control of the opening of the servo valve 7 realizes the closed-loop control of the pressure in the hydraulic cylinder cavity, and the output is stable. Dummy pressure Pd.

(2) Conventional hot casting slab production conditions

In the normal hot casting slab production condition, the electromagnet a of the two-position four-way electromagnetic reversing valve 5 is energized to control the opening of the hydraulic control check valves 801 and 802. In this state, the servo valve 7 controls the pressure Lifting and pressing of the lower roller 16. When the pressing roller 16 is pressed down, by detecting the value of the pressure sensor in the rodless cavity and the rod cavity of the hydraulic cylinder 15, the electric automatic control of the opening of the servo valve 7 realizes the closed-loop control of the pressure in the hydraulic cylinder 15 cavity, and the output is stable The dummy pressure Ph.

(3) Production conditions under light pressure

In the production condition under light pressure, the electromagnet a of the two-position four-way electromagnetic reversing valve 5 is energized, and controls the opening of the hydraulic control check valves 801 and 802. In this state, the servo valve 7 controls the tension leveler to press down The lifting and lowering positions and the lifting and lowering speeds of the rollers 16. By detecting the value of the displacement sensor on the hydraulic cylinder, the electric automatic control servo valve 7 realizes the closed-loop control of the position of the hydraulic cylinder 15, and accurately controls the depression amount of the hydraulic cylinder of the tension straightening machine. Furthermore, by detecting the values of the pressure sensors in the rodless cavity and the rod cavity of the hydraulic cylinder 15, the pressure auxiliary control is introduced. When the pressure value is within the position range given by the process, the position closed-loop control is effective. When the pressure value exceeds the process When the pressure range is given, the position closed-loop control fails, and it turns into the pressure control protection mode.

(4) Accident depressing circuit

When the servo valve 7, the pressure sensor or the displacement sensor has a component failure, the electric automatic control servo valve 7 is placed in the safe position "Y" type, and the electromagnet a of the two-position four-way electromagnetic reversing valve 5 is de-energized; in this state , the electromagnet a of the two-position two-way cut-off directional valve 4 is energized, and the emergency depressing circuit works automatically. The emergency oil source PE enters the rodless cavity of the hydraulic cylinder 15 through the pressure reducing valve 3, the two-position two-way stop-type directional valve 4, and the one-way valve 203, and the pressing roller 16 of the tensioning and leveling machine implements pressing control on the casting slab with the accident pressure , does not affect the production continuity of the continuous casting machine.

(5) Online flushing circuit

When replacing the stretching and straightening frame, hydraulic hose or causing secondary pollution to the hydraulic pipeline due to maintenance work, manually open the ball valve 105 and manually switch the oil port A and oil port C of the two-position three-way ball valve 10 when the machine is shut down for maintenance In this state, the electromagnet a of the two-position two-way cut-off directional valve 4 is energized, and the pressure oil passes through the pressure reducing valve 3, the two-position two-way cut-off directional valve 4, the one-way valve 203, and the high-pressure one-way filter Oil port C of device 1101, ball valve 105, high-pressure one-way filter 1102, and two-position three-way ball valve 10 is connected to oil return line T to form an online flushing oil return; the online flushing circuit does not pass through the servo valve 7.

Claims (10)

1. The utility model provides a withdrawal and straightening machine roll down hydraulic control system based on two accuse modes of position and pressure, withdrawal and straightening machine pneumatic cylinder (15) and withdrawal and straightening machine roll down (16) power connection, its characterized in that: the hydraulic cylinder (15) is provided with a built-in position sensor (14) for detecting the position of the hydraulic cylinder in real time; the hydraulic cylinder (15) is connected with a hydraulic pipeline comprising a servo valve group, an accident pressure control loop, a pressure sensor group, a high-pressure filter group and an online flushing loop to form a position and pressure double-control mode loop; when the dummy ingot is clamped and conveyed and the production condition of a conventional hot casting blank is adopted, a pressure closed loop is adopted as a main mode and a position auxiliary control mode is adopted, and a servo valve is controlled to output stable dummy ingot pressure Pd and hot blank pressure Ph according to different working conditions; when the production condition is lightly pressed, the position closed-loop control is adopted as a main mode, and a pressure auxiliary control mode is adopted, so that the servo valve is controlled to accurately control the pressing position of the press roll of the tension leveler.

2. The hydraulic control system for the tension leveler compression roller with position and pressure double control modes according to claim 1, characterized in that: the servo valve group mainly comprises a servo valve (7), a first hydraulic control one-way valve (801), a second hydraulic control one-way valve (802) and a two-position four-way electromagnetic directional valve (5); the servo valve (7) has a safety position function, the safety position is in a 'y' shape, and the servo valve (7) is used for controlling the lifting, pressing-down position, lifting speed and pressing-down speed of the press-down roller (16) and the pressure of two cavities of the hydraulic cylinder (15); the first hydraulic control one-way valve (801) and the second hydraulic control one-way valve (802) are used for one-way isolation of hydraulic oil at an outlet A pipeline and an outlet B pipeline of the servo valve (7); when an electromagnet a of the two-position four-way electromagnetic reversing valve (5) is electrified, a first hydraulic control one-way valve (801) and a second hydraulic control one-way valve (802) are opened;

the accident pressure control loop mainly comprises a pressure reducing valve (3), a two-position two-way stop type directional valve (4) and a third one-way valve (203); an oil port B of the pressure reducing valve (3) is connected with an energy accumulator pressure oil source PE through a first ball valve (101), and an oil port A of the pressure reducing valve (3) is connected with an oil port P1 of a two-position two-way stop-type directional valve (4); an oil port T of the two-position two-way stop type directional valve (4) is connected with an oil port A of the third one-way valve (203) and is connected with an outlet pipeline of an oil port B of the first hydraulic control one-way valve (801) through the third one-way valve (203); the third one-way valve (203) is used for one-way isolation of the accident pressure control loop and an outlet pipeline of an oil port A of the servo valve (7);

the pressure sensor group mainly comprises a first pressure sensor (1201) and a second pressure sensor (1202), the first pressure sensor (1201) detects the pressure value of a rodless cavity pipeline of the hydraulic cylinder (15) in real time, and the second pressure sensor (1202) detects the pressure value of a rod cavity pipeline of the hydraulic cylinder (15) in real time;

the high-pressure filter group filters hydraulic oil entering and returning to the servo valve (7), plays a role in protecting the servo valve (7), and mainly comprises a high-pressure filter (6), a first high-pressure one-way filter (1101) and a second high-pressure one-way filter (1102); the high-pressure filter (6) is arranged at a port P of the servo valve (7), the first high-pressure one-way filter (1101) is arranged on a port A pipeline of the servo valve (7), and the second high-pressure one-way filter (1102) is arranged on a port B pipeline of the servo valve (7);

the online flushing loop mainly comprises a two-position three-way ball valve (10) and a fifth ball valve (105) arranged on a hydraulic cylinder (15); an oil port A of the two-position three-way ball valve (10) is connected with the second high-pressure one-way filter (1102), an oil port B of the two-position three-way ball valve (10) is connected with an oil port B pipeline of the second hydraulic control one-way valve (802), an oil port C of the two-position three-way ball valve (10) is connected with an oil return pipeline T, and online flushing of an A pipeline and a B pipeline of an outlet of the servo valve (7) is achieved.

3. The hydraulic control system for the tension leveler compression roller with position and pressure double control modes according to claim 2, characterized in that: a port P of the servo valve (7) is connected with a pressure oil source P of the hydraulic system through the high-pressure filter (6) and the second ball valve (102), and a port T of the servo valve (7) is connected with an oil port A of the second one-way valve (202) and is connected with an oil return pipeline T through the second one-way valve (202); the port A of the servo valve (7) is connected with the oil port A of the first hydraulic control one-way valve (801), and the port B of the servo valve (7) is connected with the oil port A of the second hydraulic control one-way valve (802);

an oil port X of the first hydraulic control one-way valve (801) is connected with an oil port B of the two-position four-way electromagnetic directional valve (5), and an oil port L of the first hydraulic control one-way valve (801) is connected with an oil port A of the first one-way valve (201) and is connected with an oil drainage pipeline L through the first one-way valve (201);

an oil port A of the second hydraulic control one-way valve (802) is connected with an oil port B of the servo valve (7), an oil port X of the second hydraulic control one-way valve (802) is connected with an oil port B of the two-position four-way electromagnetic directional valve, and an oil port L of the second hydraulic control one-way valve (802) is connected with an oil port A of the first one-way valve (201) and is connected with an oil drainage pipeline L through the first one-way valve (201);

an oil port P of the two-position four-way electromagnetic reversing valve (5) is connected with a pressure oil source P through a second ball valve (102), and an oil port T of the two-position four-way electromagnetic reversing valve (5) is connected with an oil port A of a first one-way valve (201) and is connected with an oil drainage pipeline L through the first one-way valve (201);

an oil port A of the second one-way valve (202) is connected with an oil port T of the servo valve (7), an oil port B of the second one-way valve (202) is connected with an oil return pipeline T, and the second one-way valve (202) is used for isolating the oil return pipeline T and the oil return pipeline T of the servo valve (7) in a one-way mode and providing oil return back pressure for the servo valve (7); an oil port A of the fourth check valve (204) is connected with an oil return pipeline T, and an oil port B of the fourth check valve (204) is connected with an oil port B outlet pipeline of the second hydraulic control check valve (802); the fourth check valve (204) is used for oil supplement control of a rod cavity of the hydraulic cylinder (15) and prevents the hydraulic cylinder (15) from being damaged by air suction of the rod cavity.

4. The hydraulic control system for the tension leveler lower roll with position and pressure double control modes as claimed in claim 2 or 3, wherein: an overflow valve (9) is further arranged, a P port of the overflow valve (9) is connected with an outlet pipeline of an oil port B of the first hydraulic control one-way valve (801), and a T port of the overflow valve (9) is connected with an oil return pipeline T; the overflow valve (9) is used for overpressure protection of the rodless cavity of the hydraulic cylinder (15), so that the phenomenon that the pressure of the rodless cavity of the hydraulic cylinder (15) is too high to cause sealing damage of the rodless cavity of the hydraulic cylinder (15) is avoided, and equipment damage caused by external load is prevented.

5. The hydraulic control system for the tension leveler lower roll with position and pressure double control modes as claimed in claim 2 or 3, wherein: the accident pressure control loop is also provided with a pressure measuring joint M for measuring the pressure of the loop; in an accident state, an electromagnet a of the two-position two-way cut-off type directional valve (4) is electrified, and an accident pressure control loop automatically works; the pressure oil source PE of the energy accumulator is reduced into proper accident pressure through a pressure reducing valve (3), enters a rodless cavity of a hydraulic cylinder (15) through a two-position two-way stop type directional valve (4) and a third one-way valve (203), and a pressing roller (16) performs pressing control on a casting blank at the accident pressure.

6. The hydraulic control system for the tension leveler lower roll with position and pressure double control modes as claimed in claim 2 or 3, wherein: one end of a first pressure sensor (1201) is connected with a first high-pressure one-way filter (1101) through a third ball valve (103), the other end of the first pressure sensor is connected with a rodless cavity A of a hydraulic cylinder (15) through a hose (1301), and the pressure value of a rodless cavity pipeline is detected in real time; one end of a second pressure sensor (1202) is connected with a second high-pressure one-way filter (1102) through a fourth ball valve (104), the other end of the second pressure sensor is connected with a rod cavity B of the hydraulic cylinder (15) through another hose (1302), and the pressure value of a pipeline with the rod cavity is detected in real time.

7. The hydraulic control system for the tension leveler lower roll with position and pressure double control modes as claimed in claim 2 or 3, wherein: one end of the high-pressure filter (6) is connected with a pressure oil source P through a second ball valve (102), and the other end of the high-pressure filter is connected with an oil port P of the servo valve (7) and used for opening and closing the pressure oil source to enter the servo valve (7); one end of a first high-pressure one-way filter (1101) is connected with a pipeline of a port B of a first hydraulic control one-way valve (801), and the other end of the first high-pressure one-way filter is connected with a rodless cavity A of the hydraulic cylinder through a third ball valve (103) and a hose (1301); one end of the second high-pressure one-way filter (1102) is connected with a pipeline at the port B of the second hydraulic control one-way valve (802), and the other end of the second high-pressure one-way filter is connected with a rod cavity B of the hydraulic cylinder through a ball valve (104) and another hose (1302).

8. The hydraulic control system for the tension leveler lower roll with position and pressure double control modes as claimed in claim 2 or 3, wherein: when the two-position three-way ball valve (10) is in a working state, the oil port A is communicated with the oil port B, and when the two-position three-way ball valve is in an online flushing state, the oil port A is communicated with the oil port C; the fifth ball valve (105) is closed when the hydraulic cylinder (15) works and is opened when the on-line flushing is carried out.

9. The hydraulic control system for the tension leveler lower roll with position and pressure double control modes as claimed in claim 2 or 3, wherein: the built-in position sensor (14) is provided with a protective cover and protected by cooling air.

10. The hydraulic control system for the tension leveler lower roll with position and pressure double control modes as claimed in claim 2 or 3, wherein:

when a dummy ingot is clamped and conveyed and a conventional hot casting blank is produced, an electromagnet a of a two-position four-way electromagnetic directional valve (5) is electrified, a first hydraulic control one-way valve (801) and a second hydraulic control one-way valve (802) are controlled to be opened, a servo valve (7) controls the lifting and the pressing of a pressing roller (16) in the state, when the pressing roller (16) is pressed down, the opening degree of the servo valve (7) is automatically controlled to realize the closed-loop control of the pressure in two cavities of the hydraulic cylinder by detecting the values of pressure sensors of a rodless cavity and a rod cavity of the hydraulic cylinder (15), and stable dummy ingot pressure Pd and hot blank pressure Ph are output according to different working conditions; the method comprises the steps that position auxiliary control is introduced by detecting the numerical value of a displacement sensor on a hydraulic cylinder, when the numerical value of the displacement is within a position range given by a process, pressure closed-loop control is effective, and when the numerical value of the displacement exceeds the position range given by the process, the pressure closed-loop control fails, and a position control protection mode is switched to;

under the light-pressure production working condition, an electromagnet a of the two-position four-way electromagnetic directional valve (5) is electrified, the first hydraulic control one-way valve (801) and the second hydraulic control one-way valve (802) are controlled to be opened, and the servo valve (7) controls the lifting and pressing positions, the lifting speed and the pressing speed of the press roller (16); the position of the hydraulic cylinder (15) is controlled in a closed loop manner by automatically controlling the servo valve (7) through detecting the numerical value of a displacement sensor on the hydraulic cylinder, and the pressing amount of the press roller (16) is accurately controlled; on the basis of position control, pressure auxiliary control is introduced by detecting the numerical values of pressure sensors of a rodless cavity and a rod cavity of a hydraulic cylinder (15), when the pressure numerical value is within a position range given by the process, the position closed-loop control is effective, and when the pressure numerical value exceeds the pressure range given by the process, the position closed-loop control is invalid, and a pressure control protection mode is switched.