阅读说明：本技术 一种中间罐车比例液压升降系统及其控制方法 (Proportional hydraulic lifting system of tundish car and control method thereof ) 是由 郭佳 丘铭军 艾春璇 王训安 陈国防 宁博 于 2021-07-15 设计创作，主要内容包括：本发明提出一种中间罐车比例液压升降系统,包括：液压主管路、液压主回路、液压支流回路、位移传感器和控制器；液压主管路连通液压源；液压主回路连通液压箱；每个液压支流回路分别连接在液压主管路和液压主回路之间,每个液压支流回路上分别设置有比例阀和液压缸,液压缸的两端分别与比例阀上的两个调压管口相连通；各个位移传感器分别设置在液压缸的伸出端,用于检测液压缸的伸出长度；控制器根据每两个液压缸上的位移传感器的伸出长度差值直接或间接控制对应的比例阀的开口度,以此调节各个液压缸的伸出长度。本发明还提出一种中间罐车比例液压升降控制方法,采用以上所述的中间罐车比例液压升降系统实施。(The invention provides a proportional hydraulic lifting system of a tundish car, which comprises: the hydraulic branch flow displacement sensor comprises a hydraulic main pipeline, a hydraulic main loop, a hydraulic branch loop, a displacement sensor and a controller; the hydraulic main pipeline is communicated with a hydraulic source; the hydraulic main loop is communicated with a hydraulic tank; each hydraulic branch loop is respectively connected between the hydraulic main pipeline and the hydraulic main loop, a proportional valve and a hydraulic cylinder are respectively arranged on each hydraulic branch loop, and two ends of each hydraulic cylinder are respectively communicated with two pressure regulating pipe orifices on the proportional valve; each displacement sensor is arranged at the extending end of the hydraulic cylinder and used for detecting the extending length of the hydraulic cylinder; the controller directly or indirectly controls the opening degree of the corresponding proportional valve according to the extension length difference of the displacement sensors on each two hydraulic cylinders, so as to adjust the extension length of each hydraulic cylinder. The invention also provides a control method for the proportional hydraulic lifting of the tundish car, which is implemented by adopting the proportional hydraulic lifting system of the tundish car.)

1. The utility model provides a tundish car proportion hydraulic lifting system which characterized in that includes:

the hydraulic main pipeline (1), the hydraulic main pipeline (1) is communicated with a hydraulic source;

the hydraulic main circuit (2), the hydraulic main circuit (2) is communicated with a hydraulic tank;

the hydraulic branch circuits (3) are respectively connected between the hydraulic main circuit (1) and the hydraulic main circuit (2), each hydraulic branch circuit (3) is respectively provided with a proportional valve (4) and a hydraulic cylinder (5), and a rodless cavity and a rod cavity of the hydraulic cylinder (5) are respectively communicated with two pressure regulating pipe orifices on the proportional valve (4) through pipelines;

the displacement sensors (6) are respectively arranged at the extending end of the hydraulic cylinder (5) and used for detecting the extending length of the hydraulic cylinder (5);

and the controller directly or indirectly controls the opening degree of the corresponding proportional valve (4) according to the extension length difference of the displacement sensors (6) on each two hydraulic cylinders (5), so as to adjust the extension length of each hydraulic cylinder (5).

2. The tundish car proportional hydraulic lifting system according to claim 1, wherein the rodless cavity of each hydraulic cylinder (5) is connected with a first controllable one-way valve (7) through a pipeline, and the inlet end of each proportional valve (4) is connected with a second controllable one-way valve (8) through a pipeline.

3. The tundish car proportional hydraulic lifting system according to claim 2, further comprising a hydraulic control pipeline (9), wherein the hydraulic control pipeline (9) is connected with a plurality of two-position four-way reversing valves (10) through pipelines, the first controllable one-way valve (7) and the second controllable one-way valve (8) are hydraulic control one-way valves, and each two-position four-way reversing valve (10) is communicated with the corresponding first controllable one-way valve (7) and the corresponding second controllable one-way valve (8) on the hydraulic branch circuit (3).

4. The tundish proportional hydraulic lifting system according to claim 2, characterized in that the rodless chamber of the hydraulic cylinder (5) on each hydraulic branch circuit (3) is also connected with a safety valve (11) by a pipeline.

5. A method for controlling proportional hydraulic lifting of a tundish car, which is implemented by using the proportional hydraulic lifting system of the tundish car according to any one of claims 1 to 4, is characterized by comprising the following steps:

s001: the controller reads the data values of the displacement sensors (6) on the hydraulic cylinders (5);

s002: the extending heights of the hydraulic cylinders (5) are compared pairwise, and if the maximum out-of-tolerance between any two hydraulic cylinders is judged to be larger than a preset abnormal numerical value, the system is powered off and a fault is reported;

s003: in the process that each hydraulic cylinder (5) extends out respectively, the extending heights of all the hydraulic cylinders (5) are compared in real time, when the maximum out-of-tolerance between any two hydraulic cylinders is larger than a first preset value and smaller than an abnormal value, the opening degree of a proportional valve (4) in a hydraulic branch loop (3) where the high-position hydraulic cylinder (5) is located is reduced, the opening degrees of proportional valves (4) in hydraulic branch loops (3) where other low-position hydraulic cylinders (5) are located are kept unchanged, and when the actual displacement difference between any two hydraulic cylinders (5) is smaller than a second preset value, the opening degrees of the proportional valves (4) in the hydraulic branch loops (3) where the high-position hydraulic cylinders (5) are located are restored until hydraulic rods of all the hydraulic cylinders (5) extend out to a target displacement;

s004: in the process that each hydraulic cylinder (5) retracts respectively, the extending heights of all the hydraulic cylinders (5) are compared in real time, when the maximum out-of-tolerance between any two hydraulic cylinders is larger than a first preset value, the opening degree of a proportional valve (4) in a hydraulic branch loop (3) where the low-position hydraulic cylinder (5) is located is reduced, the opening degrees of proportional valves (4) in hydraulic branch loops (3) where other high-position hydraulic cylinders (5) are located are kept unchanged, and when the actual displacement difference between any two hydraulic cylinders (5) is smaller than a second preset value, the opening degree of the proportional valve (4) in the hydraulic branch loop (3) where the high-position hydraulic cylinder (5) is located is restored until all the hydraulic cylinders (5) retract to a target displacement;

s005: in the process of automatically adjusting the slag line, the system presets the step height a, the step time b and the cycle time T of the lifting process of the hydraulic cylinder (5) and the upper limit and the lower limit of the intermediate tank slag line.

6. The tundish car proportional hydraulic lift control method of claim 5, wherein the predetermined abnormal value is 20mm in step S002.

7. The proportional hydraulic lift control method of a tundish car according to claim 5, wherein in steps S003 and S004, the first preset value is 10 mm.

8. The proportional hydraulic lift control method of a tundish car according to claim 5, wherein in steps S005 and S004, the second preset value is 4 mm.

Technical Field

The invention belongs to the technical field of fluid transmission control of metallurgical machinery, and particularly relates to a proportional hydraulic lifting system of a tundish car and a control method thereof.

Background

In order to solve the problem that the molten steel liquid level in the crystallizer is unstable due to the fact that a slag line corrodes and perforates an immersion type water gap, the automatic slag line adjusting technology is more applied to actual production, and the automatic lifting control precision of the middle tank car is also required to be higher; the traditional manual slag changing line easily causes liquid level fluctuation, the flow field is unstable, the defects of poor adjusting precision and poor safety exist, and a tundish car lifting and control system with higher precision and automation degree is needed under the environment that a continuous casting machine system tends to be high in precision and automation.

Disclosure of Invention

The present invention proposes a tundish car proportional hydraulic lifting system and a control method thereof to overcome the above problems or at least partially solve or alleviate them.

A tundish car proportional hydraulic lifting system comprising:

the hydraulic main pipeline is communicated with a hydraulic source;

the hydraulic main circuit is communicated with the hydraulic tank;

each hydraulic branch circuit is respectively connected between the hydraulic main pipeline and the hydraulic main circuit, a proportional valve and a hydraulic cylinder are respectively arranged on each hydraulic branch circuit, and a rodless cavity and a rod cavity of the hydraulic cylinder are respectively communicated with two pressure regulating pipe orifices on the proportional valve through pipelines;

the displacement sensors are respectively arranged at the extending end of the hydraulic cylinder and used for detecting the extending length of the hydraulic cylinder;

and the controller directly or indirectly controls the opening degree of the corresponding proportional valve according to the extension length difference of the displacement sensors on each two hydraulic cylinders so as to adjust the extension length of each hydraulic cylinder.

The invention also provides the following implementation modes of the proportional hydraulic lifting system of the tundish car.

Preferably, the rodless cavity of each hydraulic cylinder is connected with a first controllable one-way valve through a pipeline, and the inlet end of each proportional valve is connected with a second controllable one-way valve through a pipeline.

Preferably, the hydraulic branch circuit further comprises a hydraulic control pipeline, the hydraulic control pipeline is connected with a plurality of two-position four-way reversing valves through pipelines respectively, the first controllable one-way valve and the second controllable one-way valve are hydraulic control one-way valves, and each two-position four-way reversing valve is communicated with the corresponding first controllable one-way valve and the corresponding second controllable one-way valve on the hydraulic branch circuit respectively.

Preferably, the rodless chamber of the hydraulic cylinder on each hydraulic branch circuit is further connected with a relief valve through a pipeline.

A control method for proportional hydraulic lifting of a tundish car is implemented by adopting the proportional hydraulic lifting system of the tundish car, and comprises the following steps:

s001: the controller reads the data values of the displacement sensors on the hydraulic cylinders;

s002: comparing every two extending heights of each hydraulic cylinder, and if the maximum out-of-tolerance between any two extending heights is judged to be larger than a preset abnormal numerical value, powering off the system and reporting a fault;

s003: in the process that each hydraulic cylinder extends out respectively, the extending heights of all the hydraulic cylinders are compared in real time, when the maximum out-of-tolerance between any two hydraulic cylinders is larger than a first preset value and smaller than an abnormal value, the opening degree of a proportional valve in a hydraulic branch loop where the high-position hydraulic cylinder is located is reduced, the opening degrees of proportional valves in hydraulic branch loops where other low-position hydraulic cylinders are located are kept unchanged, and when the actual displacement difference between any two hydraulic cylinders is smaller than a second preset value, the opening degrees of the proportional valves in the hydraulic branch loops where the high-position hydraulic cylinders are located are restored until hydraulic rods of all the hydraulic cylinders extend out to a target displacement;

s004: in the process that all hydraulic cylinders retract respectively, the extension heights of all the hydraulic cylinders are compared in real time, when the maximum out-of-tolerance between any two hydraulic cylinders is larger than a first preset value, the opening degree of a proportional valve in a hydraulic branch loop where the low-position hydraulic cylinder is located is reduced, the opening degrees of proportional valves in hydraulic branch loops where other high-position hydraulic cylinders are located are kept unchanged, and when the actual displacement difference between any two hydraulic cylinders is smaller than a second preset value, the opening degrees of the proportional valves in the hydraulic branch loops where the high-position hydraulic cylinders are located are restored until all the hydraulic cylinders retract to the target displacement;

s005: in the process of automatically adjusting the slag line, the system presets the step height a, the step time b and the cycle time T of the hydraulic cylinder in the lifting process, and the upper limit and the lower limit of the intermediate tank slag line.

In step S002, the predetermined abnormality value is 20 mm.

In steps S003 and S004, the first preset value is 10 mm.

In steps S005 and S004, the second preset value is 4 mm.

The invention discloses a proportional hydraulic lifting system of a tundish car and a control method thereof.A proportional hydraulic system is added into a lifting device, namely, each hydraulic cylinder is controlled by a closed-loop control system consisting of an independent proportional valve and a displacement sensor to control the actual displacement output value of the cylinder, and then the actual output displacement of four hydraulic cylinders is controlled by an algorithm, so that the problem of unstable molten steel liquid level in a crystallizer caused by corrosion and perforation of a submerged nozzle by a slag line at present is solved.

Drawings

FIG. 1 is a schematic structural view of a proportional hydraulic lifting system of a tundish car of the invention;

FIG. 2 is a target control process diagram of a submerged nozzle slag regulating line of the proportional hydraulic lifting control method of the tundish car.

In the above figures, 1 a hydraulic main line; 2 hydraulic main loop; 3 a hydraulic branch circuit; 4, a proportional valve; 5, a hydraulic cylinder; 6 a displacement sensor; 7 a first controllable one-way valve; 8 a second controllable one-way valve; 9 hydraulic control lines; 10 two-position four-way reversing valve; 11 safety valve.

Detailed Description

The invention is further illustrated by the following specific examples.

Example 1

Referring to fig. 1, the invention provides a proportional hydraulic lifting system of a tundish car, comprising: the hydraulic branch flow control system comprises a hydraulic main pipeline 1, a hydraulic main circuit 2, a plurality of hydraulic branch flow circuits 3, a plurality of displacement sensors 6 and a controller; the hydraulic main pipeline 1 is communicated with a hydraulic source; the hydraulic main loop 2 is communicated with a hydraulic tank; each hydraulic branch loop 3 is respectively connected between the hydraulic main pipeline 1 and the hydraulic main pipeline 2, a proportional valve 4 and a hydraulic cylinder 5 are respectively arranged on each hydraulic branch loop 3, and a rodless cavity and a rod cavity of the hydraulic cylinder 5 are respectively communicated with two pressure regulating pipe orifices on the proportional valve 4 through pipelines; each displacement sensor 6 is respectively arranged at the extending end of the hydraulic cylinder 5 and used for detecting the extending length of the hydraulic cylinder 5; the controller directly or indirectly controls the opening degree of the corresponding proportional valve 4 according to the extension length difference of the displacement sensor 6 on each two hydraulic cylinders 5, so as to adjust the extension length of each hydraulic cylinder 5.

Hydraulic pressure main line 1 is connected with oil tank and hydraulic pump, the hydraulic pump can be with the hydraulic oil pump in the oil tank in going into hydraulic pressure main line 1, hydraulic pressure main circuit 2 is linked together with the oil tank, it has four hydraulic pressure tributary return circuits 3 to connect between hydraulic pressure main line 1 and hydraulic pressure main circuit 2, be connected with proportional valve 4 and pneumatic cylinder 5 on every hydraulic pressure tributary return circuit 3 respectively, two mouths of pipe of proportional valve 4 are direct or indirect with the no pole chamber of pneumatic cylinder 5 with have the pole chamber to be connected, can control the no pole chamber of pneumatic cylinder 5 and the flow that has the pole chamber through proportional valve 4, thereby adjust the no pole chamber of pneumatic cylinder 5 and the flow that has the pole chamber, and then control pneumatic cylinder 5 stretches out or retracts. The four hydraulic cylinders 5 are respectively connected with a lifting device of the middle tank car, the four displacement sensors 6 respectively arranged on the extending sections of the four hydraulic cylinders 5 can feed the extending length of each hydraulic cylinder 5 back to the controller, and the controller can judge whether to change the PID parameter of the proportional valve 4 according to the maximum displacement difference of every two hydraulic cylinders 5 in each hydraulic cylinder 5, namely the opening degree of the proportional valve 4, so as to adjust and change the flow of the rodless cavity and the rodless cavity of the hydraulic cylinder 5, thereby ensuring that the extending length of each hydraulic cylinder 5 in the lifting system of the middle tank car is consistent when the middle tank car ascends or descends, and finally ensuring that the liquid level in the middle tank car is balanced and stable.

Example 2

Referring to fig. 1, on the basis of embodiment 1, a first controllable check valve 7 is connected to a rodless cavity of each hydraulic cylinder 5 through a pipeline, and a second controllable check valve 8 is connected to an inlet end of each proportional valve 4 through a pipeline.

The first controllable one-way valve 7 and the second controllable one-way valve 8 can ensure that when the system is powered off or a pipeline is broken, the hydraulic oil in each hydraulic branch loop 3 cannot flow back, so that the hydraulic cylinders 5 cannot suddenly retract and descend rapidly under the gravity of the tundish car to cause accidents.

Example 3

Referring to fig. 1, on the basis of embodiment 2, the hydraulic branch circuit further includes a hydraulic control pipeline 9, the hydraulic control pipeline 9 is connected with a plurality of two-position four-way reversing valves 10 through pipelines, the first controllable one-way valve 7 and the second controllable one-way valve 8 are hydraulic control one-way valves, and each two-position four-way reversing valve 10 is communicated with the corresponding first controllable one-way valve 7 and the second controllable one-way valve 8 on the hydraulic branch circuit 3.

The conduction direction of the first controllable one-way valve 7 faces to a rodless cavity of the hydraulic cylinder 5, the conduction direction of the second controllable one-way valve 8 is opposite to a pressure oil port of the proportional valve 4, and in the normal ascending or descending process of the system, each two-position four-way reversing valve 10 on the four hydraulic branch circuits 3 is always in an electrified state, so that the first controllable one-way valve 7 and the second controllable one-way valve 8 on each hydraulic branch circuit 3 can be kept in an open state, and the proportional hydraulic lifting system can normally run. When the two-position four-way reversing valve 10 is powered off, the first controllable one-way valve 7 and the second controllable one-way valve 8 are in a one-way conduction state, the hydraulic cylinder 5 can be prevented from acting, the oil supply of the pressure oil port of the proportional valve 4 can be cut off, and the proportional hydraulic lifting system is in a fault stop state.

Example 4

Referring to fig. 1, on the basis of embodiment 2, the rodless chamber of the hydraulic cylinder 5 on each of the hydraulic branch circuits 3 is also connected with a relief valve 11 through a pipe.

When the pressure in the rodless cavity of the hydraulic cylinder 5 reaches the limit value of the safety valve 11, the safety valve 11 is conducted, hydraulic oil is discharged, the pressure in the rodless cavity of the hydraulic cylinder 5 is reduced, and accidents can be prevented.

Example 5

Referring to fig. 1, the invention also provides a method for controlling proportional hydraulic lifting of a tundish car, which is implemented by adopting any one of the proportional hydraulic lifting systems of the tundish car, and comprises the following steps: s001: the controller reads the data value of the displacement sensor 6 on each hydraulic cylinder 5; s002: comparing every two extending heights of each hydraulic cylinder 5, and if the maximum out-of-tolerance between any two extending heights is judged to be larger than a preset abnormal numerical value, powering off the system and reporting a fault; s003: in the process that the hydraulic rods of all the hydraulic cylinders 5 extend out respectively, comparing the extending heights of all the hydraulic cylinders 5 in real time, and when the maximum out-of-tolerance between any two hydraulic cylinders 5 is larger than a first preset value and smaller than an abnormal value, reducing the opening degree of the proportional valve 4 in the hydraulic branch circuit 3 where the high-position hydraulic cylinder 5 is located, so that the opening degrees of the proportional valves 4 in the hydraulic branch circuits 3 where other low-position hydraulic cylinders 5 are located are kept unchanged, and when the actual displacement difference between any two hydraulic cylinders 5 is smaller than a second preset value, restoring the opening degree of the proportional valve 4 in the hydraulic branch circuit 3 where the high-position hydraulic cylinder 5 is located until the hydraulic rods of all the hydraulic cylinders 5 extend out to a target displacement; s004: in the process that the hydraulic rods of all the hydraulic cylinders 5 retract respectively, the extension heights of all the hydraulic cylinders 5 are compared in real time, when the maximum out-of-tolerance between any two hydraulic cylinders 5 is larger than a first preset value, the opening degree of the proportional valve 4 in the hydraulic branch circuit 3 where the low-position hydraulic cylinder 5 is located is reduced, the opening degrees of the proportional valves 4 in the hydraulic branch circuits 3 where other high-position hydraulic cylinders 5 are located are kept unchanged, and when the actual displacement difference between any two hydraulic cylinders 5 is smaller than a second preset value, the opening degrees of the proportional valves 4 in the hydraulic branch circuits 3 where the high-position hydraulic cylinders 5 are located are restored until the hydraulic rods of all the hydraulic cylinders 5 retract to a target displacement; s005: in the process of automatically adjusting the slag line, the system presets the step height a, the step time b and the cycle time T of the lifting process of the lifting hydraulic cylinder 5, the upper limit of the slag adjusting line of the tundish and the lower limit of the slag adjusting line of the tundish.

In step S002, the predetermined abnormality value is 20 mm. In steps S003 and S004, the first preset value is 10mm, and the second preset value is 4 mm.

The controller detects the displacement of the extending end of each hydraulic cylinder 5 on the six hydraulic branch circuits 3 through each liquid level sensor 6, compares the displacement values of each hydraulic cylinder 5 pairwise, and when the maximum over-tolerance of the displacement of any two hydraulic cylinders 5 is larger than the preset abnormal value, namely 20mm, the system is powered off and reports faults. 20mm is the maximum allowable error of the middle tank car mechanical equipment assembly, the situation that the hydraulic cylinder 5 is possible to damage the equipment irreversibly when the assembly error exceeds the range is determined, at the moment, the controller enables the two-position four-way reversing valves 10 on the four hydraulic branch circuits 3 to be completely de-energized, the first controllable one-way valve 7 and the second controllable one-way valve 8 are in a one-way conduction state so as to cut off the oil supply of the pressure oil port of the proportional valve 4, meanwhile, the hydraulic cylinder 5 stops acting, at the moment, the system is in a fault stop state, and whether the related hydraulic branch circuits 3 or the electric components are normally connected or not needs to be checked. After the fault is eliminated, the single hydraulic branch circuit 3 is manually adjusted, namely the two-position four-way reversing valve 10 in the circuit is electrified, the opening degree of the proportional valve 4 in the circuit is adjusted to enable the hydraulic cylinders 5 to ascend or descend, the maximum out-of-tolerance of displacement between every two of the four hydraulic cylinders 5 is within a second preset numerical value, namely 4mm, and the system is automatically controlled by a delivery controller, wherein the controller can be a control box or a remote cloud-end controller.

In the normal ascending process of the system, the two-position four-way reversing valve 10 is in a constantly powered state, when the maximum over-tolerance of the elongation of any two hydraulic cylinders 5 is larger than a first preset value, namely 10mm, the controller reduces the PID parameter of the proportional valve 4 related to the hydraulic cylinder 5 at the high position, namely the opening degree of the proportional valve 4 is reduced, meanwhile, the opening degree of the proportional valve 4 related to the hydraulic cylinder 5 at the low position is kept unchanged, the displacement of the hydraulic cylinder 5 at the low position can catch up with the displacement of the hydraulic cylinder 5 at the high position, when the actual displacement difference between any two hydraulic cylinders 5 is smaller than a second preset value, namely 4mm, the controller recovers the opening degree of the proportional valve 4 related to the hydraulic cylinder 5 at the high position, and the opening degree of the proportional valve 4 is automatically adjusted in the whole process until the hydraulic cylinder 5 moves to a target displacement;

in the normal descending process of the system, the two-position four-way reversing valve 10 is in a constantly powered state, when the maximum over-tolerance of the elongation of any two hydraulic cylinders 5 is larger than a first preset value, namely 10mm, the controller reduces the PID parameters of the proportional valve related to the hydraulic cylinder 5 at the low position, namely the opening degree of the proportional valve 4, meanwhile, the opening degree of the proportional valve 4 related to the hydraulic cylinder 5 at the high position is kept unchanged, the displacement of the hydraulic cylinder 5 at the high position can be reduced to the displacement of the hydraulic cylinder 5 at the low position, and when the actual displacement difference between any two hydraulic cylinders 5 is smaller than a second preset value, namely 4mm, the controller restores the opening degree of the proportional valve 4 related to the hydraulic cylinder 5 at the low position until the opening degree of the proportional valve 4 is automatically adjusted in the whole process until the hydraulic cylinder 5 moves to the target displacement.

As shown in fig. 2, in the automatic slag line adjusting process, the system first performs step length conversion, the controller sets a step virtual axis, a virtual axis curve of the submerged nozzle, that is, a lifting curve of the hydraulic cylinder 5 is preset, a step height a, a step time b, a cycle time T, and an upper limit and a lower limit of the slag line adjusting of the tundish are set in the first-stage PLC, in the automatic slag line adjusting process of the submerged nozzle, the tundish lifting is performed at a slow speed, and the system has preset a PID parameter of the operating condition proportional valve 4, so that the speed of the hydraulic cylinder 5 is about 10 mm/s.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.