A test bench simulating the hydraulic synchronization of two cylinders in a rolling mill

Abstract

The present invention belongs to the technical field of rolling mill hydraulic system control test, and discloses a test bench for simulating the hydraulic synchronization of two cylinders of a rolling mill. By installing two groups of piston rod-opposite design push-down cylinders and loading cylinders on the test stand, and installing a built-in displacement sensor on the test stand to collect the displacement information of the piston rod of the push-down cylinder, and controlling the position closed-loop oil circuit in the push-down cylinder hydraulic system through an industrial computer to control it online, thereby ensuring the control accuracy of the positions of the two push-down cylinder pistons, and controlling the two loading cylinder hydraulic systems through pressure closed-loop control by an industrial computer to adjust the loading forces of the two loading cylinders online in real time, thus realizing the two-cylinder synchronization control experiment under different eccentric load conditions. The present invention uses the test bench to conduct relevant eccentric load offline tests, which not only helps to improve the control accuracy of the synchronization of the two cylinders of the rolling mill, but also provides a new idea for the hydraulic systems of other metallurgical equipment with multi-cylinder synchronous motion, which has guiding significance for actual production.

Description

Technical Field

[0001] The invention belongs to the technical field of rolling mill hydraulic system control test, and in particular relates to a test bench for simulating the hydraulic synchronization of two cylinders of a rolling mill. Background Art

[0002] The rolling mill is a large and complex electromechanical and hydraulic integrated equipment with the characteristics of variability, strong coupling, nonlinearity, time-varying, and multiple constraints. With the rapid development of rolling mills towards large-scale, high-speed, continuous, and intelligent operation, as well as the adoption of a large number of new technologies and processes, new challenges have been raised to the control accuracy of the two-cylinder synchronization of the rolling mill and the stability of the equipment.

[0003] Since the internal parameters and external loads of the hydraulic press-down systems on the operating side and the transmission side of the rolling mill are inconsistent, and there is a certain uncertainty in the load, this will cause the dynamic and static performance of the press-down systems on the operating side and the transmission side of the rolling mill to be different and the press-down systems to be asynchronous, thus affecting the thickness and quality of the rolled plates on both sides. During the synchronous operation and dynamic adjustment of the two cylinders of the rolling mill, the elastic roller bends under the strong rolling force, resulting in serious eccentric loads on the drive shaft and the operating side press-down system, affecting the control accuracy of the press-down oil cylinder.

[0004] Therefore, there is an urgent need to build relevant test equipment to conduct relevant offline tests on how to achieve two-cylinder synchronous control of the rolling mill under the action of eccentric load. Summary of the invention

[0005] In order to solve the influence of different dynamic and static performances of the pressing systems on both sides of the rolling mill and the asynchronism of the pressing systems on the thickness and quality of the rolled plates in the above background technology, further offline tests on how to achieve two-cylinder synchronous control on the operation side and the transmission side of the rolling mill under the action of eccentric load are carried out, so as to facilitate the study of the test function of the rolling mill to achieve two-cylinder synchronous movement under the action of eccentric load. To this end, the present invention specially designs and provides a rolling mill two-cylinder synchronization test device and hydraulic system.

[0006] In order to meet the test function of studying the synchronous movement of two cylinders in the relevant off-line test of the rolling mill under the action of the eccentric load, the present invention adopts the following technical scheme: a test bench simulating the hydraulic synchronization of two cylinders of the rolling mill, which includes an oil cylinder test device and a hydraulic control system matched therewith;

[0007] The oil cylinder test device comprises a test bracket, which adopts a main frame welded by steel plates, and two oil cylinder installation grooves are respectively arranged on the inner sides of the top beam and the bottom beam of the main frame, and the two oil cylinder installation grooves located on the top beam are respectively installed with pressing oil cylinders, and the two oil cylinder installation grooves located on the bottom beam are respectively installed with loading oil cylinders, and the two pressing oil cylinders and the two loading oil cylinders are respectively arranged opposite to each other, and the piston rods of the pressing oil cylinders located on the same side of the main frame are opposite to the piston rods of the loading oil cylinders;

[0008] The hydraulic control system includes two pressing cylinder hydraulic systems and a constant back pressure system matched with the two pressing cylinders, two loading cylinder hydraulic systems matched with the two loading cylinders, and a main pressure oil pipe and a main return oil pipe connected to each system, and both oil pipes are connected to the oil tank, and an oil pump connected to the output end of the industrial computer is arranged on the main pressure oil pipe as an oil pressure power source, and all control valves in each system are respectively connected to the output end of the industrial computer, and execute the instructions issued by the industrial computer to control the on and off of the oil circuit;

[0009] The structures and principles of the hydraulic systems of the two pressing oil cylinders are the same, and both include a servo valve with an oil port A connected to a high-pressure filter on the main pressure oil pipe, an oil port P connected to an oil port B of the high-pressure filter, an oil port A of the servo valve connected in two ways to an oil port A of the pressing oil cylinder and an oil port A of the first relief valve, an oil port T of the servo valve and an oil port T of the first relief valve connected to the main return oil pipe, and a first pressure sensor connected to the input end of an industrial computer is connected to the rodless chamber oil port A of each pressing oil cylinder through a tee, and the two first pressure sensors are used to collect oil pressure information of the rodless chambers of the two pressing oil cylinders respectively;

[0010] The structures and principles of the hydraulic systems of the two loading cylinders are the same, and both include a proportional pressure reducing valve connected to the main pressure oil pipe with an oil port P, a Y-type functional electromagnetic reversing valve connected to the oil port A of the proportional pressure reducing valve, the oil port A of the Y-type functional electromagnetic reversing valve connected to the oil port B of the loading cylinder, the oil port B of the Y-type functional electromagnetic reversing valve connected to the oil port A of the second hydraulically controlled one-way valve, the oil port B of the second hydraulically controlled one-way valve connected to the oil port A of the same loading cylinder, the oil port T of the Y-type functional electromagnetic reversing valve connected to the main return oil pipe, and a second pressure sensor connected to the input end of an industrial computer is connected to the rodless chamber oil port A of each loading cylinder through a tee, the two second pressure sensors are respectively used to collect the oil pressure information of the rodless chambers of the two loading cylinders, and the two proportional pressure reducing valves are respectively controlled by the industrial computer to adjust the working pressure of the oil in the rodless chambers of the two loading cylinders;

[0011] The constant back pressure system includes a first pressure reducing valve whose oil port A is connected to the main pressure oil pipe, the oil port B of the first pressure reducing valve is divided into two paths and respectively connected to the oil port P of the second two-position reversing valve and the oil port A of the third overflow valve, the oil port A of the second two-position reversing valve is divided into two paths and connected to the B ports of the two pressing cylinders, the oil port T of the second two-position reversing valve is connected to the oil port P of the second accumulator, the oil port T of the second accumulator is connected to the main return oil pipe, and a third pressure sensor connected to the input end of the industrial computer is connected in parallel to the rod chamber oil port B of the two pressing cylinders, and the third pressure sensor is used to collect the oil pressure information of the rod chambers of the two pressing cylinders.

[0012] As a further supplement to the above technical solution, each loading cylinder hydraulic system also includes an electromagnetic ball valve connected to the output end of the industrial computer, and the oil port A and oil port B of the electromagnetic ball valve are respectively connected to the oil port A and oil port B of the loading cylinder to form a differential circuit, which facilitates speeding up the return speed of the loading cylinder.

[0013] As a further supplement to the above technical solution, each loading cylinder hydraulic system also includes a second overflow valve whose oil port A is connected to the oil port A of the loading cylinder, and the oil port T of the second overflow valve is connected to the main oil return pipe. The second overflow valve is used to prevent the oil pressure in the rodless chamber of the loading cylinder from overloading and plays a role of automatic overflow protection.

[0014] As a further supplement to the above technical solution, the hydraulic control system also includes an oil drain pipe connected to the oil tank, and the external drain port of the second two-position reversing valve and the external drain port of the first pressure reducing valve are connected to the oil drain pipe.

[0015] As a further supplement to the above technical solution, the constant back pressure system also includes a second pressure reducing valve whose oil port A is connected to the oil port B of the first pressure reducing valve, the oil port B of the second pressure reducing valve is connected to the oil port A of the fourth overflow valve, the oil port A of the fourth overflow valve is connected to the oil port T of the second two-position reversing valve, the external drain port of the second pressure reducing valve is connected to the oil drain pipe, and the oil port T of the fourth overflow valve is connected to the main oil return pipe T, thereby forming a double protection against overload of the constant back pressure system.

[0016] As a further supplement to the above technical solution, each down-pressure cylinder hydraulic system also includes a first accumulator having an oil port P connected to an oil port A of a high-pressure filter, and an oil port T of the first accumulator is connected to a main oil return pipe T. The first accumulator is used to absorb the pressure pulsation shock during the synchronous operation of the two cylinders and to serve as an emergency power source for fluid replenishment.

[0017] As a further supplement to the above technical solution, each hydraulic system of the pressing cylinder also includes a first hydraulically controlled one-way valve and a first two-position reversing valve respectively connected to the output end of the industrial computer, the oil port P of the first two-position reversing valve is connected to the oil port A of the high-pressure filter, the oil port A of the first two-position reversing valve is connected to the oil port X of the first hydraulically controlled one-way valve, the oil port B of the first hydraulically controlled one-way valve is connected to the oil port A of the pressing cylinder, and the oil port A of the first hydraulically controlled one-way valve is connected to the main return oil pipe T. The first two-position reversing valve controls the on-off of the oil circuit of the first hydraulically controlled one-way valve to realize emergency unloading of each of the hydraulic systems of the pressing cylinder.

[0018] As a further supplement to the above technical solution, each push-down cylinder hydraulic system also includes a manual unloading valve. The oil port A of the high-pressure filter is connected to the main return oil pipe T through the manual unloading valve. The manual unloading valve is used to realize manual unloading of the push-down cylinder hydraulic system.

[0019] A sensor mounting hole is provided on the top beam of the main frame, in which a built-in displacement sensor is arranged. Each built-in displacement sensor is connected to the input end of an industrial computer and is used to collect displacement information of the piston of the depression cylinder. The output end of the industrial computer is connected to a servo valve, thereby forming a position closed-loop control to accurately control the displacement of the piston rod of the depression cylinder.

[0020] As a further limitation and explanation of the above technical solution, the test bracket also includes a crossbeam installed in the middle of the main frame, and two guide holes are respectively opened on the crossbeam. The piston rod of the pressing cylinder located on the same side of the main frame passes through the guide hole and is opposite to the piston rod of the loading cylinder. A plurality of fixing screw holes are respectively opened on both sides of the bottom beam of the main frame, and the main frame is fixed to the ground by bolts through the screw holes.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The test bench designed by the present invention to simulate the hydraulic synchronization of two cylinders of a rolling mill is designed by installing two sets of piston rods on the test support. The pressing cylinder and loading cylinder are designed to be opposite to each other, so as to simulate the hydraulic pressing system on both sides of the operation side and the transmission side of the rolling mill. In addition, a built-in displacement sensor is installed on the test support to collect the displacement information of the piston rod of the pressing cylinder, and the position closed-loop oil circuit in the hydraulic system of the pressing cylinder is controlled online by an industrial computer to ensure the control accuracy of the piston positions of the two pressing cylinders. At the same time, the hydraulic systems of the two loading cylinders are controlled by an industrial computer to perform pressure closed-loop control, so that the loading force of the two loading cylinders can be adjusted online in real time, realizing the two-cylinder synchronization control experiment under different eccentric load conditions. Carrying out relevant eccentric load offline tests on this test bench is helpful to improve the control accuracy of the dual-cylinder synchronization of the rolling mill, and improve the flatness and yield rate of the plate.

[0023] 2. The present invention designs triple pressure overload protection in the hydraulic system of the two pressing oil cylinders, which are overload overflow protection of the first overflow valve, emergency unloading protection of the first two-position reversing valve and the first hydraulically controlled one-way valve, and manual unloading protection of the manual unloading valve, thereby improving the stability and reliability of the hydraulic system. At the same time, in the process of simulating the synchronous operation of the two cylinders of the rolling mill, it can effectively avoid the occurrence of sudden pressure changes or accidents in the pressing oil cylinder system.

[0024] 3. The present invention provides first accumulators in the hydraulic systems of the two pressing oil cylinders. The two accumulators can not only absorb the pressure pulsation impact during the synchronous operation of the two cylinders, but also serve as an emergency power source to replenish fluid.

[0025] 4. The constant back pressure system designed in the present invention provides a constant back pressure for the rod chamber of the pressing cylinder during the actual synchronous operation of the two cylinders of the simulating rolling mill. The constant back pressure system can prevent the piston and the connecting parts from falling by gravity during operation, and avoids the suction phenomenon during the pressing process and the unstable working phenomenon such as the stalling of the hydraulic cylinder. At the same time, it can serve as a power source for returning the hydraulic cylinder.

[0026] 5. The test bench designed by the present invention for simulating the hydraulic synchronization of two cylinders of a rolling mill can provide a new idea for the hydraulic system of other metallurgical equipment with multi-cylinder synchronous motion, and has guiding significance for actual production. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to make those skilled in the art more clearly understand the technical solution protected by the present invention, the following is a supplementary illustration and explanation of the specific structure of the hydraulic control system and the oil cylinder test device involved. The symbols marked in the figure are limited to the explanation of the technical solution.

[0028] Figure 1 It is a principle diagram of the hydraulic control system of the rolling mill two-cylinder synchronous test bench of the present invention;

[0029] Figure 2 It is a structural schematic diagram of a rolling mill two-cylinder synchronous test device of the present invention;

[0030] Figure 3 It is a structural schematic diagram of a test bracket in a rolling mill two-cylinder synchronous test device of the present invention.

[0031] In the figure: a cylinder test device 100, a pressing cylinder hydraulic system 200, a loading cylinder hydraulic system 300, and a constant back pressure system 400.

[0032] The oil cylinder test device includes a pressing oil cylinder 10.1, a loading oil cylinder 10.2, a built-in displacement sensor 10.3, and a test bracket 10.4;

[0033] The test bracket includes a main frame 10.41, a crossbeam 10.42, a guide hole 10.43, a cylinder mounting groove 10.44, a sensor mounting hole 10.45, and a fixing screw hole 10.46.

[0034] The hydraulic system of the pressing cylinder includes a high-pressure filter 20.1, a servo valve 20.2, a first pressure sensor 20.3, a first overflow valve 20.4, a first hydraulically controlled one-way valve 20.5, a first two-position reversing valve 20.6, a manual unloading valve 20.7, and a first accumulator 20.8;

[0035] The loading cylinder hydraulic system includes a proportional pressure reducing valve 30.1, a Y-type functional electromagnetic reversing valve 30.2, a second hydraulically controlled one-way valve 30.3, a second overflow valve 30.4, an electromagnetic ball valve 30.5, and a second pressure sensor 30.6.

[0036] The constant back pressure system comprises a first pressure reducing valve 40.1, a second pressure reducing valve 40.2, a second two-position reversing valve 40.3, a third pressure sensor 40.4, a third overflow valve 40.5, a fourth overflow valve 40.6, and a second accumulator 40.7.

[0037] exist Figure 1 In the figure, P represents the main pressure oil pipe, T represents the main return oil pipe, and Y represents the drain oil pipe; YVH1, YVH2, YVH3, YVH4, YVH5, YVH6, YVH7, YVH8, and YVH9 represent the electromagnets of each solenoid control valve respectively, and YB1 and YB2 represent the driving reversing device force motors of the two servo valves respectively. DETAILED DESCRIPTION

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, Figures 1 to 3 Five embodiments will be fully introduced, among which the information processing of industrial computing as a sensor device and the information processing performed by each electromagnetic control valve belong to the prior art for those skilled in the art, so the present invention will not be described in detail. The drawings described below are only embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work, which are regarded as equivalent technical solutions of the present invention. Embodiment 1

[0039] As attached Figures 1 to 3 As shown, a test bench for simulating the hydraulic synchronization of two cylinders of a rolling mill comprises two parts: a cylinder test device 100 and a hydraulic control system matched therewith;

[0040] First, the oil cylinder test device 100 includes a test bracket 10.4, which is a main frame 10.41 welded with steel plates, and a plurality of fixing screw holes 10.46 are respectively opened on both sides of the bottom beam of the main frame 10.41, and the main frame 10.41 is fixedly installed on the ground by bolts, and two oil cylinder installation grooves 10.44 are respectively arranged on the inner sides of the top beam and the bottom beam of the main frame 10.41, and the two oil cylinder installation grooves 10.44 located on the top beam are respectively installed with a pressing oil cylinder 10.46. .1, loading cylinders 10.2 are respectively installed in the two cylinder installation grooves 10.44 located on the bottom beam, the two pressing cylinders 10.1 and the two loading cylinders 10.2 are arranged opposite to each other, a cross beam 10.42 is arranged in the middle of the main frame 10.41, and two guide holes 10.43 are respectively opened on the cross beam 10.42, and the piston rods of the pressing cylinders 10.1 located on the same side of the main frame 10.41 pass through the guide holes 10.43 and are opposite to the piston rods of the loading cylinders 10.2. At the same time, a sensor mounting hole 10.45 is opened on the top beam of the main frame 10.41, and a built-in displacement sensor 10.3 is arranged therein. Each built-in displacement sensor 10.3 is connected to the input end of the industrial computer and is used to collect the displacement information of the piston of the pressing cylinder 10.1. The output end of the industrial computer is connected to the servo valve 20.2, thereby forming a position closed-loop control to accurately control the displacement of the piston rod of the pressing cylinder 10.1.

[0041] Second, the hydraulic control system includes two pressing cylinder hydraulic systems 200 and a constant back pressure system 400 matched with the two pressing cylinders 10.1, two loading cylinder hydraulic systems 300 matched with the two loading cylinders 10.2, and a main pressure oil pipe and a main return oil pipe connected to each system, plus an oil drain pipe, and the three oil pipes are all connected to the oil tank. An oil pump connected to the output end of the industrial computer is provided on the main pressure oil pipe as a hydraulic power source. All control valves in each system are respectively connected to the output end of the industrial computer, and execute the instructions issued by the industrial computer to control the on and off of the oil circuit;

[0042] The following introduces the relevant hydraulic control system parts in the order of two pressing cylinders and two loading cylinders.

[0043] (1) The structures and principles of the two hydraulic systems 200 of the pressing cylinders are the same, and both include a servo valve 20.2 whose oil port A is connected to a high-pressure filter 20.1 on the main pressure oil pipe, an oil port P is connected to an oil port B of the high-pressure filter 20.1, and an oil port A of the servo valve 20.2 is connected to an oil port A of the pressing cylinder 10.1 and an oil port A of the first relief valve 20.4 in two ways, respectively. An oil port T of the servo valve 20.2 is connected to an oil port B of the first relief valve 20.4 and an oil port B of the first relief valve 20.4. and the oil port T of the first overflow valve 20.4 are respectively connected to the main return oil pipe, and the first pressure sensor 20.3 connected to the input end of the industrial computer is connected to the rodless chamber oil port A of each pressing cylinder 10.1 through a tee, and the two first pressure sensors 20.3 are respectively used to collect the oil pressure information of the rodless chambers of the two pressing cylinders 10.1; the constant back pressure system 400 includes a first pressure reducing valve 40.1 with an oil port A connected to the main pressure oil pipe, and the oil port B of the first pressure reducing valve 40.1 is divided into two ways and is respectively connected to the oil port P of the second two-position reversing valve 40.3 and the oil port A of the third overflow valve 40.5, and the second two The oil port A of the reversing valve 40.3 is connected to the B ports of the two pressing cylinders 10.1 in two ways, the oil port T of the second two-position reversing valve 40.3 is connected to the oil port P of the second accumulator 40.7, the oil port T of the second accumulator 40.7 is connected to the main return oil pipe, the external leakage port of the second two-position reversing valve 40.3 and the external leakage port of the first pressure reducing valve 40.1 are connected to the oil leakage pipe, and the third pressure sensor 40.4 connected to the input end of the industrial computer is connected in parallel to the rod cavity oil port B of the two pressing cylinders 10.1, and the third pressure sensor 40.4 is used to collect the oil pressure information of the rod cavities of the two pressing cylinders 10.1.

[0044] (2) The two loading cylinder hydraulic systems 300 have the same structure and principle, and both include a proportional pressure reducing valve 30.1 whose oil port P is connected to the main pressure oil pipe, a Y-type functional solenoid reversing valve 30.2 whose oil port P is connected to the oil port A of the proportional pressure reducing valve 30.1, an oil port A of the Y-type functional solenoid reversing valve 30.2 is connected to the oil port B of the loading cylinder 10.2, an oil port B of the Y-type functional solenoid reversing valve 30.2 is connected to the oil port A of the second hydraulically controlled one-way valve 30.3, and an oil port B of the second hydraulically controlled one-way valve 30.3 is connected to the same. The oil port A of the loading cylinder 10.2 and the oil port T of the Y-type function electromagnetic reversing valve 30.2 are connected to the main oil return pipe, and the rodless cavity oil port A of each loading cylinder 10.2 is connected to a second pressure sensor 30.6 connected to the input end of the industrial computer through a three-way connection. The two second pressure sensors 30.6 are respectively used to collect the oil pressure information of the two rodless cavities of the loading cylinders 10.2, and respectively control the two proportional pressure reducing valves 30.1 through the industrial computer to adjust the working pressure of the oil in the rodless cavities of the two loading cylinders 10.2; Embodiment 2

[0045] In order to improve the stability and safety of the loading cylinder hydraulic system in the double cylinder test. In the first embodiment, we add an electromagnetic ball valve 30.5 connected to the output end of the industrial computer in each of the loading cylinder hydraulic systems 300, and the specific connection method is that the oil port A and the oil port B of the electromagnetic ball valve 30.5 are respectively connected to the oil port A and the oil port B of the loading cylinder 10.2 to form a differential circuit, and the electromagnetic ball valve 30.5 is convenient for accelerating the return speed of the loading cylinder 10.2.

[0046] In addition to the above-mentioned improvements, each of the loading cylinder hydraulic systems 300 also includes a second overflow valve 30.4 whose oil port A is connected to the oil port A of the loading cylinder 10.2, and the oil port T of the second overflow valve 30.4 is connected to the main oil return pipe. The second overflow valve 30.4 is used to prevent the oil pressure in the rodless chamber of the loading cylinder 10.2 from overloading and plays a role of automatic overflow protection. Embodiment 3

[0047] In Example 1, in order to prevent sudden changes or accidents in the pressure of the constant back pressure system, we add the following countermeasures to the constant back pressure system 400: the oil port A is connected to the second pressure reducing valve 40.2 of the oil port B of the first pressure reducing valve 40.1, the oil port B of the second pressure reducing valve 40.2 is connected to the oil port A of the fourth overflow valve 40.6, the oil port A of the fourth overflow valve 40.6 is connected to the oil port T of the second two-position reversing valve 40.3, the external drain port of the second pressure reducing valve 40.2 is connected to the oil drain pipe, and the oil port T of the fourth overflow valve 40.6 is connected to the main return oil pipe T, thereby forming a double protection against overload of the constant back pressure system 400.

[0048] In this embodiment, a constant back pressure control valve group is formed by the coordinated control and cooperation of the first pressure reducing valve 40.1, the second pressure reducing valve 40.2, the third relief valve 40.5, the fourth relief valve 40.6 and the second accumulator 40.7. In the industrial computer, the opening pressure value of the third relief valve 40.5 is set to be greater than the B port pressure of the first pressure reducing valve 40.1 by 1-2 MPa, and the opening pressure value of the fourth relief valve 40.6 is set to be greater than the B port pressure of the second pressure reducing valve 40.2 by 1-2 MPa.

[0049] In the simulation of the actual synchronous operation of the two cylinders of the rolling mill, the constant back pressure system 400 provides a constant back pressure for the rod chamber of the pressing cylinder 10.2 to prevent the piston and the connecting parts from falling by gravity during operation, and to ensure the suction of air during the pressing process and avoid unstable working phenomena such as stalling of the hydraulic cylinder, and serve as a power source for retracting the hydraulic cylinder. Embodiment 4

[0050] In the process of simulating the synchronous operation of the two cylinders of the rolling mill, in order to prevent the first overflow valve from responding untimely and causing hydraulic overload, in addition to the solution of automatic overflow protection of the first overflow valve against oil pressure overload in Example 1, we add two pressure overload protection technical solutions to the hydraulic systems of the two down-pressing cylinders, thereby forming a triple protection of pressure overload for the hydraulic system of the down-pressing cylinders.

[0051] The first type: each hydraulic system 200 of the pressing cylinder also includes a first hydraulically controlled one-way valve 20.5 and a first two-position reversing valve 20.6 respectively connected to the output end of the industrial computer, the oil port P of the first two-position reversing valve 20.6 is connected to the oil port A of the high-pressure filter 20.1, the oil port A of the first two-position reversing valve 20.6 is connected to the oil port X of the first hydraulically controlled one-way valve 20.5, the oil port B of the first hydraulically controlled one-way valve 20.5 is connected to the oil port A of the pressing cylinder, and the oil port A of the first hydraulically controlled one-way valve 20.5 is connected to the main return oil pipe T. The first two-position reversing valve 20.6 controls the on-off of the oil circuit of the first hydraulically controlled one-way valve 20.5 to realize emergency unloading of each of the hydraulic systems 200 of the pressing cylinder.

[0052] The second type: each pressing cylinder hydraulic system 200 also includes a manual unloading valve 20.7, and the oil port A of the high-pressure filter 20.1 is connected to the main return oil pipe T through the manual unloading valve 20.7. The manual unloading valve 20.7 is used to realize manual unloading of the pressing cylinder hydraulic system 200. Embodiment 5

[0053] In implementation one and implementation four, in order to avoid the pressure pulsation shock during the synchronous operation of the two cylinders, each pressing cylinder hydraulic system 200 also includes a first accumulator 20.8 whose oil port P is connected to the oil port A of the high-pressure filter 20.1, and the oil port T of the first accumulator 20.8 is connected to the main return oil pipe T. The first accumulator 20.8 can not only absorb the pressure pulsation shock during the synchronous operation of the two cylinders, but also serve as an emergency power source to replenish fluid.

[0054] Its hydraulic system control method and working principle:

[0055] During specific operation, the industrial computer collects the position information of the piston rods of the two pressing cylinders 10.1 through two built-in displacement sensors 10.3, and forms a position closed loop with two servo valves 20.2 to accurately control the positions of the piston rods of the two pressing cylinders 10.1.

[0056] When simulating the synchronous operation of two cylinders, the force motor YB1 and the force motor YB2 are energized, and the hydraulic oil of the main pressure oil pipe P flows into the rodless chamber of the pressing oil cylinder 10.1 through the AB channel of the high-pressure filter 20.1 and the PA channel of the servo valve 20.2. Similarly, the hydraulic oil of the main pressure oil pipe P flows into the rodless chamber of the other pressing oil cylinder 10.1, thereby driving the piston rods of the two pressing oil cylinders 10.1 to move downward synchronously. At the same time, the electromagnet YVH8 in the constant back pressure system is energized, and the hydraulic oil of the main pressure oil pipe P flows into the rod chambers of the two pressing oil cylinders 10.1 through the AB channel of the first pressure reducing valve 40.1 and the PA channel of the second two-position reversing valve 40.3, respectively, to provide the system with a constant back pressure of 2-3MPa.

[0057] In the hydraulic system of the loading cylinder, the electromagnet YVH4 and the electromagnet YVH2 are energized at the same time, and the hydraulic oil in the main pressure oil pipe P flows into the rodless chamber of the loading cylinder 10.2 through the PA channel of the proportional pressure reducing valve 30.1, the PB channel of the Y-type functional electromagnetic reversing valve 30.2, and the AB channel of the second hydraulic control one-way valve 30.3; similarly, the hydraulic oil in the main pressure oil pipe P flows into the rodless chamber of the other loading cylinder 10.2. The loading force of the loading cylinder 10.2 is adjusted online in real time by forming a pressure closed loop through the proportional pressure reducing valve 30.1 and the second pressure sensor 30.6, thereby realizing the coordinated control of the two loading cylinders 10.2 to carry out the two-cylinder synchronous control experiment under different eccentric load conditions.

[0058] The above shows and describes the main features and advantages of the present invention. For those skilled in the art, it is obvious that the specific implementation of the present invention is not limited to the details of the above exemplary embodiments, and the creative ideas and design ideas of the present invention can be realized in other specific forms without departing from the spirit or basic features of the present invention, which should be equivalent to the protection scope disclosed in the technical solution of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the present invention.

[0059] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A test bench simulating the hydraulic synchronization of two cylinders of a rolling mill, characterized by: It includes an oil cylinder test device (100) and a hydraulic control system matched therewith; The oil cylinder test device (100) comprises a test bracket (10.4), which adopts a main frame (10.41) welded with steel plates, and two oil cylinder installation grooves (10.44) are respectively arranged on the inner sides of the top beam and the bottom beam of the main frame (10.41), and a pressing oil cylinder (10.1) is respectively installed in the two oil cylinder installation grooves (10.44) located on the top beam, and a loading oil cylinder (10.2) is respectively installed in the two oil cylinder installation grooves (10.44) located on the bottom beam, and the two pressing oil cylinders (10.1) and the two loading oil cylinders (10.2) are respectively arranged in opposition, and the piston rods of the pressing oil cylinders (10.1) and the piston rods of the loading oil cylinders (10.2) located on the same side of the main frame (10.41) are opposite to each other; The hydraulic control system comprises two pressing cylinder hydraulic systems (200) and a constant back pressure system (400) matched with the two pressing cylinders (10.1), two loading cylinder hydraulic systems (300) matched with the two loading cylinders (10.2), and a main pressure oil pipe and a main return oil pipe connected to each system, and both oil pipes are connected to the oil tank, and an oil pump connected to the output end of the industrial computer is arranged on the main pressure oil pipe as an oil pressure power source, and all control valves in each system are respectively connected to the output end of the industrial computer, and execute instructions issued by the industrial computer to control the on and off of the oil circuit; The two hydraulic systems (200) of the pressing oil cylinders have the same structure and principle, and both include an oil port A connected to a high-pressure filter (20.1) on a main pressure oil pipe, an oil port P connected to a servo valve (20.2) of an oil port B of the high-pressure filter (20.1), an oil port A of the servo valve (20.2) connected in two ways to an oil port A of the pressing oil cylinder (10.1) and an oil port A of a first overflow valve (20.4), an oil port T of the servo valve (20.2) and an oil port T of the first overflow valve (20.4) connected to a main return oil pipe, and a first pressure sensor (20.3) connected to an input end of an industrial computer is connected to an oil port A of the rodless chamber of each pressing oil cylinder (10.1) via a tee, and the two first pressure sensors (20.3) are used to collect oil pressure information of the rodless chambers of the two pressing oil cylinders (10.1); The two loading cylinder hydraulic systems (300) have the same structure and principle, and both include a proportional pressure reducing valve (30.1) with an oil port P connected to the main pressure oil pipe, a Y-type functional electromagnetic reversing valve (30.2) with an oil port P connected to an oil port A of the proportional pressure reducing valve (30.1), an oil port A of the Y-type functional electromagnetic reversing valve (30.2) connected to an oil port B of the loading cylinder (10.2), an oil port B of the Y-type functional electromagnetic reversing valve (30.2) connected to an oil port A of a second hydraulically controlled one-way valve (30.3), and an oil port B of the second hydraulically controlled one-way valve (30.3) connected to the same. The oil port A of the loading oil cylinder (10.2) and the oil port T of the Y-type functional electromagnetic reversing valve (30.2) are connected to the main oil return pipe, and a second pressure sensor (30.6) connected to the input end of the industrial computer is connected to the rodless chamber oil port A of each loading oil cylinder (10.2) through a three-way connection. The two second pressure sensors (30.6) are respectively used to collect the oil pressure information of the rodless chambers of the two loading oil cylinders (10.2), and respectively control the two proportional pressure reducing valves (30.1) through the industrial computer to adjust the working pressure of the oil in the rodless chambers of the two loading oil cylinders (10.2); The constant back pressure system (400) comprises a first pressure reducing valve (40.1) whose oil port A is connected to the main pressure oil pipe, the oil port B of the first pressure reducing valve (40.1) is divided into two paths and respectively connected to the oil port P of the second two-position reversing valve (40.3) and the oil port A of the third overflow valve (40.5), the oil port A of the second two-position reversing valve (40.3) is divided into two paths and connected to the B ports of the two pressing oil cylinders (10.1), the oil port T of the second two-position reversing valve (40.3) is connected to the oil port P of the second accumulator (40.7), the oil port T of the second accumulator (40.7) is connected to the main return oil pipe, and the third pressure sensor (40.4) connected to the input end of the industrial computer is connected in parallel to the rod chamber oil port B of the two pressing oil cylinders (10.1), and the third pressure sensor (40.4) is used to collect the oil pressure information of the rod chambers of the two pressing oil cylinders (10.1).

2. A test bench for simulating the hydraulic synchronization of two cylinders of a rolling mill according to claim 1, characterized in that: Each loading cylinder hydraulic system (300) further comprises an electromagnetic ball valve (30.5) connected to the output end of the industrial computer, and the oil port A and the oil port B of the electromagnetic ball valve (30.5) are respectively connected to the oil port A and the oil port B of the loading cylinder (10.2), forming a differential circuit, which facilitates accelerating the return speed of the loading cylinder (10.2).

3. A test bench for simulating the hydraulic synchronization of two cylinders of a rolling mill according to claim 2, characterized in that: Each loading cylinder hydraulic system (300) further comprises a second overflow valve (30.4) whose oil port A is connected to the oil port A of the loading cylinder (10.2); an oil port T of the second overflow valve (30.4) is connected to the main oil return pipe; the second overflow valve (30.4) is used to prevent the oil pressure in the rodless chamber of the loading cylinder (10.2) from being overloaded and to play a role of automatic overflow protection.

4. A test bench for simulating the hydraulic synchronization of two cylinders of a rolling mill according to any one of claims 1 to 3, characterized in that: The hydraulic control system further comprises an oil drain pipe connected to the oil tank, and an external drain port of the second two-position reversing valve (40.3) and an external drain port of the first pressure reducing valve (40.1) are connected to the oil drain pipe.

5. A test bench for simulating the hydraulic synchronization of two cylinders of a rolling mill according to claim 4, characterized in that: The constant back pressure system (400) further comprises a second pressure reducing valve (40.2) whose oil port A is connected to the oil port B of the first pressure reducing valve (40.1), the oil port B of the second pressure reducing valve (40.2) is connected to the oil port A of the fourth overflow valve (40.6), the oil port A of the fourth overflow valve (40.6) is connected to the oil port T of the second two-position reversing valve (40.3), the external drain port of the second pressure reducing valve (40.2) is connected to the oil drain pipe, and the oil port T of the fourth overflow valve (40.6) is connected to the main oil return pipe T, thereby forming a double protection against overload of the constant back pressure system (400).

6. A test bench for simulating the hydraulic synchronization of two cylinders of a rolling mill according to claim 5, characterized in that: Each down-pressure cylinder hydraulic system (200) further comprises a first accumulator (20.8) having an oil port P connected to an oil port A of a high-pressure filter (20.1), an oil port T of the first accumulator (20.8) connected to a main oil return pipe T, and the first accumulator (20.8) is used to absorb the pressure pulsation shock during the synchronous operation of the two cylinders and to serve as an emergency power source for fluid replenishment.

7. A test bench for simulating the hydraulic synchronization of two cylinders of a rolling mill according to claim 6, characterized in that: Each hydraulic system (200) of the pressing oil cylinder further comprises a first hydraulically controlled one-way valve (20.5) and a first two-position reversing valve (20.6) respectively connected to the output end of the industrial computer; the oil port P of the first two-position reversing valve (20.6) is connected to the oil port A of the high-pressure filter (20.1); the oil port A of the first two-position reversing valve (20.6) is connected to the oil port X of the first hydraulically controlled one-way valve (20.5); the oil port B of the first hydraulically controlled one-way valve (20.5) is connected to the oil port A of the pressing oil cylinder; the oil port A of the first hydraulically controlled one-way valve (20.5) is connected to the main oil return pipe T; and the first two-position reversing valve (20.6) controls the on-off of the oil circuit of the first hydraulically controlled one-way valve (20.5) to realize emergency unloading of each hydraulic system (200) of the pressing oil cylinder.

8. A test bench for simulating the hydraulic synchronization of two cylinders of a rolling mill according to claim 7, characterized in that: Each press-down cylinder hydraulic system (200) further comprises a manual unloading valve (20.7); the oil port A of the high-pressure filter (20.1) is connected to the main oil return pipe T via the manual unloading valve (20.7); the manual unloading valve (20.7) is used to realize manual unloading of the press-down cylinder hydraulic system (200).

9. A test bench for simulating the hydraulic synchronization of two cylinders of a rolling mill according to any one of claims 1 to 3 or any one of claims 5 to 8, characterized in that: A sensor mounting hole (10.45) is provided on the top beam of the main frame (10.41), in which a built-in displacement sensor (10.3) is arranged. Each built-in displacement sensor (10.3) is connected to an input end of an industrial computer and is used to collect displacement information of the piston of the pressing cylinder (10.1). The output end of the industrial computer is connected to a servo valve (20.2), thereby forming a position closed-loop control to accurately control the displacement of the piston rod of the pressing cylinder (10.1).

10. A test bench for simulating the hydraulic synchronization of two cylinders of a rolling mill according to claim 9, characterized in that: The test bracket (10.4) further comprises a crossbeam (10.42) installed in the middle of the main frame (10.41), and two guide holes (10.43) are respectively provided on the crossbeam (10.42). The piston rod of the pressing cylinder (10.1) located on the same side of the main frame (10.41) passes through the guide hole (10.43) and is opposed to the piston rod of the loading cylinder (10.2). A plurality of fixing screw holes (10.46) are respectively provided on both sides of the bottom beam of the main frame (10.41), and the main frame (10.41) is fixedly installed on the ground by bolts.

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