Hydraulic system, control method of hydraulic system and rolling mill

Abstract

The invention discloses a hydraulic system, a control method of the hydraulic system and a rolling mill, and relates to the technical field of hydraulic systems. One end of the first hydraulic pump set is connected with the oil tank, and the other end of the first hydraulic pump set is connected with one end of the second hydraulic pump set; one end of the high-pressure filter is connected with the other end of the second hydraulic pump set; one end of the double-connection one-way valve group is connected with the other end of the high-pressure filter; the thickness control hydraulic cylinder is connected with the other end of the double-connection one-way valve set and used for adjusting the roll gap of the rolling mill. The energy consumption of the hydraulic system is reduced, and meanwhile the operation efficiency of the hydraulic system is improved.

Description

Technical Field

[0001] The present application relates to the technical field of hydraulic systems, and in particular to a hydraulic system, a control method of a hydraulic system, and a rolling mill. Background Art

[0002] Hydraulic systems are widely used in industry. A large number of hydraulic systems are used in the hot rolling process of steel enterprises. Among them, the automatic thickness control hydraulic system is the core technology, which is used to control the roll gap of the rolling mill and is the most basic guarantee for the thickness control of strip steel products. However, the existing hydraulic system has technical problems such as high energy consumption. Summary of the invention

[0003] The embodiments of the present application provide a hydraulic system, a control method for the hydraulic system and a rolling mill, which are used to solve technical problems such as high energy consumption of the hydraulic system in the prior art.

[0004] In a first aspect of an embodiment of the present application, a hydraulic system is provided, the hydraulic system comprising:

[0005] Oil tank, used to store hydraulic oil;

[0006] a first hydraulic pump group and a second hydraulic pump group, one end of the first hydraulic pump group is connected to the oil tank, and the other end is connected to one end of the second hydraulic pump group;

[0007] A high-pressure filter, one end of which is connected to the other end of the second hydraulic pump unit;

[0008] A double-connected one-way valve group, one end of which is connected to the other end of the high-pressure filter;

[0009] The thickness control hydraulic cylinder is connected to the other end of the double-connected one-way valve group and is used to adjust the roll gap of the rolling mill.

[0010] The hydraulic system in this embodiment replaces the valve control system in the conventional hydraulic system with the first hydraulic pump group and the second hydraulic pump group, thereby simplifying the structure of the hydraulic system, thereby reducing the oil circulation volume of the hydraulic system, reducing the energy consumption of the hydraulic system, and improving the efficiency of the hydraulic system.

[0011] According to a second aspect of the present invention, a control method for a hydraulic system is provided, comprising:

[0012] The hydraulic oil in the oil tank is transmitted to the high-pressure filter through the first hydraulic pump group and the second hydraulic pump group;

[0013] Filter the hydraulic oil through a high-pressure filter to obtain filtered hydraulic oil;

[0014] After the thickness control hydraulic cylinder receives the filtered hydraulic oil, the roll gap of the rolling mill is adjusted through the thickness control hydraulic cylinder.

[0015] The control method of the hydraulic system in this embodiment replaces the valve control system in the conventional hydraulic system with the first hydraulic pump group and the second hydraulic pump group, thereby simplifying the structure of the hydraulic system, thereby reducing the oil circulation volume of the hydraulic system, reducing the energy consumption of the hydraulic system, and improving the efficiency of the hydraulic system.

[0016] According to a third aspect of the present invention, a rolling mill is proposed, comprising: a hydraulic system as defined in the first aspect above, and thus having all the beneficial technical effects of the hydraulic system defined in the second aspect above, which will not be elaborated herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0018] Figure 1 A structural diagram of a hydraulic system provided in an embodiment of the present application;

[0019] Figure 2 A flow chart of a control method for a hydraulic system provided in an embodiment of the present application;

[0020] in, Figure 1 The corresponding relationship between the reference numerals and the component names is as follows:

[0021] 100 hydraulic system, 101 oil tank, 102 first hydraulic pump group, 103 second hydraulic pump group, 104 high pressure filter, 105 double check valve group, 106 thickness control hydraulic cylinder, 107 pump suction port ball valve, 108 main oil inlet pipeline, 109 pump outlet check valve, 110 piston accumulator, 111 unloading electromagnetic reversing valve, 112 first pressure sensor, 113 first position sensor, 114 second pressure sensor, 115 nitrogen bottle, 116 stop valve block, 117 first ball valve, 118 hydraulic control check valve, 119 reversing valve, 120 electromagnetic overflow valve, 121 second ball valve, 122 second position sensor, 123 third pressure sensor, 124 proportional three-way pressure reducing valve, 125 accumulator, 126 stop valve block, 127 return oil main pipeline, 128 return oil check valve, 129 unloading oil pipeline. DETAILED DESCRIPTION

[0022] In order to better understand the technical solutions provided by the embodiments of this specification, the technical solutions of the embodiments of this specification are described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of this specification and the specific features in the embodiments are detailed descriptions of the technical solutions of the embodiments of this specification, rather than limitations on the technical solutions of this specification. In the absence of conflict, the embodiments of this specification and the technical features in the embodiments can be combined with each other.

[0023] In this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements limited by the statement "comprise one..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements. The term "more than two" includes two or more than two situations.

[0024] In some embodiments, Figure 1 As shown, in an embodiment of the present application, a hydraulic system 100 is provided, comprising:

[0025] An oil tank 101 is used to store hydraulic oil;

[0026] A first hydraulic pump group 102 and a second hydraulic pump group 103, wherein one end of the first hydraulic pump group 102 is connected to the oil tank 101, and the other end is connected to one end of the second hydraulic pump group 103;

[0027] A high pressure filter 104, one end of the high pressure filter 104 is connected to the other end of the second hydraulic pump unit 103;

[0028] A double-connected one-way valve assembly 105, one end of which is connected to the other end of the high-pressure filter 104;

[0029] The thickness control hydraulic cylinder 106 is connected to the other end of the double-connected one-way valve group 105 and is used to adjust the roll gap of the rolling mill.

[0030] In this embodiment, the hydraulic system 100 is used for controlling a rolling mill. The hydraulic system 100 includes a mailbox, and an oil tank 101 is a device for storing hydraulic oil.

[0031] Exemplarily, the oil tank 101 is used to store, purify, settle, cool, heat and filter oil. Its volume is determined according to the amount of oil and circulation frequency required by the hydraulic system 100. The oil tank 101 should include auxiliary systems and accessories such as a circulation pump unit and a return oil filter.

[0032] The hydraulic system 100 includes a first hydraulic pump group 102 and a second hydraulic pump group 103 . One end of the first hydraulic pump group 102 is connected to the oil tank 101 , and the other end of the first hydraulic pump group 102 is connected to one end of the second hydraulic pump group 103 .

[0033] Exemplarily, the first hydraulic pump group 102 is composed of a servo motor and a fixed displacement pump, and is used to replenish hydraulic oil to the hydraulic system 100 .

[0034] Exemplarily, the second hydraulic pump group 103 is composed of a servo motor and a bidirectional quantitative pump, and can switch between two closed-loop control modes, thereby controlling the action of the thickness control hydraulic cylinder 106 to achieve the adjustment of the roll gap.

[0035] The hydraulic system 100 includes a high-pressure filter 104 and a double-connected one-way valve group 105 . One end of the high-pressure filter 104 is connected to the other end of the second hydraulic pump group 103 . One end of the double-connected one-way valve group 105 is connected to the other end of the high-pressure filter 104 .

[0036] Exemplarily, the high-pressure filter 104 is used to filter the oil supplied from the second hydraulic pump group 103 to the thickness control hydraulic cylinder 106, and is used in conjunction with the double-connected one-way valve group 105. The oil passes through the high-pressure filter 104 only when the oil is supplied to the thickness control hydraulic cylinder 106. When the roll gap opens and the thickness control hydraulic cylinder 106 is lifted, the oil is supplied from the thickness control hydraulic cylinder 106 to the energy storage device through the second hydraulic pump group 103. The oil passes through the other one-way valve of the double-connected one-way valve group 105 and does not pass through the high-pressure filter 104.

[0037] Exemplarily, the double-connected one-way valve group 105 is used to realize one-way passage of oil through the high-pressure filter 104 .

[0038] The hydraulic system 100 includes a thickness control hydraulic cylinder 106 , which is connected to the other end of the double-connected one-way valve group 105 and is used to adjust the roll gap of the rolling mill.

[0039] For example, the hydraulic system 100 is used to adjust the roll gap of the rolling mill to realize the roll gap control function of the rolling mill.

[0040] The hydraulic system 100 in this embodiment replaces the valve control system in the conventional hydraulic system 100 by the first hydraulic pump group 102 and the second hydraulic pump group 103, thereby simplifying the structure of the hydraulic system 100, thereby reducing the oil circulation volume of the hydraulic system 100, reducing the energy consumption of the hydraulic system 100, and improving the efficiency of the hydraulic system 100.

[0041] In some embodiments, a hydraulic system 100 is provided in an embodiment of the present application, and the hydraulic system 100 further includes:

[0042] A pump oil suction port ball valve 107, used to isolate the oil tank 101 and the first hydraulic pump unit 102;

[0043] A main oil inlet pipeline 108, the main oil inlet pipeline 108 is connected to the oil tank 101;

[0044] A pump outlet check valve 109, used to isolate the hydraulic pump group and the main oil inlet pipeline 108;

[0045] The piston accumulator 110 is connected to the thickness control hydraulic cylinder 106 and is used to store and provide hydraulic oil inside the thickness control hydraulic cylinder 106;

[0046] The unloading electromagnetic reversing valve 111 is used to unload the oil in the piston accumulator 110 and the main oil inlet pipeline 108 back to the oil tank 101 .

[0047] In this embodiment, the hydraulic system 100 further includes a pump suction port ball valve 107 for isolating the oil tank 101 and the first hydraulic pump unit 102 .

[0048] The hydraulic system 100 further includes a main oil inlet pipeline 108 , which is connected to the oil tank 101 and is a pipeline for the circulation of pressurized oil.

[0049] The hydraulic system 100 further includes a pump outlet non-return valve 109 for isolating the hydraulic pump group from the main oil inlet pipeline 108 .

[0050] The hydraulic system 100 further includes a piston accumulator 110 connected to the thickness control hydraulic cylinder 106 for storing and providing hydraulic oil inside the thickness control hydraulic cylinder 106 .

[0051] Exemplarily, the piston accumulator 110 includes two chambers, one chamber is used to store and provide hydraulic oil for the two chambers in the thickness control hydraulic cylinder 106, and the other chamber is used to store nitrogen, and the pressure of the nitrogen is used to maintain a certain pressure in the main oil inlet pipeline 108 of the hydraulic system 100. The volume of the piston accumulator 110 is calculated and determined according to the oil change amount and the pressure change range.

[0052] The hydraulic system 100 further includes a load-releasing electromagnetic reversing valve 111 for releasing the oil in the piston accumulator 110 and the main oil inlet pipeline 108 back to the oil tank 101 , and is generally used when oil and pressure need to be released during maintenance.

[0053] In some embodiments, a hydraulic system 100 is provided in an embodiment of the present application, and the hydraulic system 100 further includes:

[0054] A first pressure sensor 112, used to detect the pressure of the main oil inlet pipeline 108;

[0055] A first position sensor 113, used to detect the position of the piston of the piston accumulator 110;

[0056] The second pressure sensor 114 is used to detect the pressure of the piston accumulator 110 .

[0057] In this embodiment, the hydraulic system 100 also includes a first pressure sensor 112, a first position sensor 113 and a second pressure sensor 114. The first pressure sensor 112 is used to detect the pressure of the main oil inlet pipeline 108, the first position sensor 113 is used to detect the position of the piston of the piston accumulator 110, and the second pressure sensor 114 is used to detect the pressure of the piston accumulator 110.

[0058] Exemplarily, the pressure sensor is used to detect the main oil inlet pipeline 108, and two pressure values ​​P5 / P6 are set. P5 controls the start of the first hydraulic pump group 102 to replenish the piston accumulator 110, and P6 controls the stop of the first hydraulic pump group 102. The values ​​of P5 and P6 are determined according to the actual debugging of the hydraulic system 100.

[0059] When the pressure of the first sensor is lower than P5 (the pressure set according to system debugging), the first hydraulic pump group 102 starts to replenish oil for the piston accumulator 110. When the pressure reaches the set value P6 (the pressure set according to system debugging), the first hydraulic pump group 102 stops.

[0060] Exemplarily, the second pressure sensor 114 is used to detect the pressure of a nitrogen chamber in the piston accumulator 110 and provide an alarm signal for nitrogen pressure replenishment.

[0061] Exemplarily, the first position sensor 113 is used to detect the position of the piston in the piston accumulator 110 and provide a start signal and an alarm signal for timely replenishment of oil and nitrogen.

[0062] In some embodiments, a hydraulic system 100 is provided in an embodiment of the present application, and the hydraulic system 100 further includes:

[0063] A nitrogen cylinder 115, used to store nitrogen to balance the pressure of the piston accumulator 110;

[0064] A stop valve block 116, connected to the nitrogen bottle 115 and the piston accumulator 110, for opening or closing the nitrogen bottle 115;

[0065] The first ball valve 117 is used to isolate the connection between the piston accumulator 110 and the main oil inlet pipeline 108 and the nitrogen cylinder 115 .

[0066] In this embodiment, the hydraulic system 100 further includes a nitrogen bottle 115 , a stop valve block 116 and a first ball valve 117 .

[0067] The nitrogen cylinder 115 is used to store nitrogen to balance the pressure of the two chambers of the piston accumulator 110. The number of nitrogen cylinders 115 is determined by calculation based on the volume of the piston accumulator 110 and the pressure variation range.

[0068] The stop valve block 116 is used to connect the nitrogen bottle 115 and the piston accumulator 110, and can close the nitrogen bottle 115 and relieve pressure and fill it with nitrogen.

[0069] The first ball valve 117 is used to isolate the connection between the piston accumulator 110 and the main oil inlet pipeline 108 and the nitrogen cylinder 115 .

[0070] In some embodiments, a hydraulic system 100 is provided in an embodiment of the present application, and the hydraulic system 100 further includes:

[0071] A hydraulically controlled one-way valve 118, used to isolate the second hydraulic pump group 103 and the thickness control hydraulic cylinder 106;

[0072] The reversing valve 119 is used to control the hydraulically controlled one-way valve 118;

[0073] The electromagnetic overflow valve 120 is connected to the thickness control hydraulic cylinder 106;

[0074] The second ball valve 121 is connected to the thickness control hydraulic cylinder 106 and is used to isolate the thickness control hydraulic cylinder 106 .

[0075] In this embodiment, the hydraulic system 100 further includes a hydraulically controlled one-way valve 118 , a reversing valve 119 , an electromagnetic relief valve 120 and a second ball valve 121 .

[0076] Among them, the hydraulically controlled one-way valve 118 is used to isolate the second hydraulic pump group 103 and the thickness control hydraulic cylinder 106, and the reversing valve 119 is used to control the hydraulically controlled one-way valve 118. When the electromagnet of the reversing valve 119 is energized, the hydraulically controlled one-way valve 118 opens in the reverse direction. At this time, the hydraulically controlled one-way valve 118 is equivalent to an oil channel. When the electromagnet of the reversing valve 119 loses power, the hydraulically controlled one-way valve 118 cannot open in the reverse direction. At this time, the hydraulically controlled one-way valve 118 allows oil to supply oil to the thickness control hydraulic cylinder 106, but does not allow the thickness control hydraulic cylinder 106 to return oil.

[0077] The electromagnetic overflow valve 120 is connected to the rod chamber of the thickness control hydraulic cylinder 106, and has two functions, one is the overflow valve, and the other is the unloading valve. When the thickness control hydraulic cylinder 106 is in the fast opening mode, the electromagnetic overflow valve 120 electromagnet b is energized, and it is the unloading valve function. The oil in the rodless chamber of the thickness control hydraulic cylinder 106 is quickly unloaded through the electromagnetic overflow valve 120, the thickness control hydraulic cylinder 106 is quickly retracted, and the roller gap is quickly opened. Which function is realized by which the electromagnetic overflow valve 120 is energized can be determined by selecting the model of the pilot valve. The set pressure of the overflow valve is P4, and P4 should be greater than the pressure of the hydraulic system 100 during normal operation to ensure that the overflow valve is in a normally closed state in the normal working mode.

[0078] The second ball valve 121 is connected to the thickness control hydraulic cylinder 106 and is used to isolate the connection between the two chambers in the thickness control hydraulic cylinder 106 and the hydraulic system 100 .

[0079] In some embodiments, a hydraulic system 100 is provided in an embodiment of the present application, and the hydraulic system 100 further includes:

[0080] A second position sensor 122 for measuring the piston position of the thickness control hydraulic cylinder 106;

[0081] The third pressure sensor 123 is used to measure the pressure data of the thickness control hydraulic cylinder 106 .

[0082] In this embodiment, the hydraulic system 100 further includes a second position sensor 122 and a third pressure sensor 123 .

[0083] The second position sensor 122 is used to measure the piston position of the thickness control hydraulic cylinder 106 and realize position closed-loop control with the second hydraulic pump group 103 .

[0084] The third pressure sensor 123 is used to measure the pressure data of the thickness control hydraulic cylinder 106. Specifically, it is used to measure the pressure of the rodless chamber and the rod chamber in the thickness control hydraulic cylinder 106. The rodless chamber pressure and the hydraulic pump group realize the pressure closed-loop control, and the rod chamber pressure provides a comparison basis for the set pressure of the proportional three-way pressure reducing valve 124. The pressure detection values ​​of the two chambers of the hydraulic cylinder are also the basis for calculating the pressing force.

[0085] In some embodiments, a hydraulic system 100 is provided in an embodiment of the present application, and the hydraulic system 100 further includes:

[0086] A proportional three-way pressure reducing valve 124 is connected to the thickness control hydraulic cylinder 106 and is used to supply oil to the thickness control hydraulic cylinder 106;

[0087] An accumulator 125 for adjusting the pressure of the thickness control hydraulic cylinder 106;

[0088] The stop valve block 116 is respectively connected to the thickness control hydraulic cylinder 106 and the accumulator 125 , and is used to open or close the accumulator 125 .

[0089] In this embodiment, the hydraulic system 100 further includes a proportional three-way pressure reducing valve 124 , an accumulator 125 and a shut-off valve block 116 .

[0090] The proportional three-way pressure reducing valve 124 is connected to the rod chamber of the thickness control hydraulic cylinder 106 and is used to supply oil to the rod chamber of the thickness control hydraulic cylinder 106. Specifically, it is used to supply oil to the rod chamber of the thickness control hydraulic cylinder 106. There are two set pressures P1 / P2. P1 is the working mode pressure, which is the hydraulic back pressure, and P2 is the roll changing mode pressure, which is greater than the P1 value. The pressure values ​​P1 and P2 are determined according to actual conditions.

[0091] The accumulator 125 is used to adjust the pressure stability of the thickness control hydraulic cylinder 106. Specifically, it is used to stabilize the rod chamber pressure of the thickness control hydraulic cylinder 106 and reduce pressure fluctuations. The nitrogen filling pressure is P3, which is generally set to 70-80% of the common hydraulic pressure.

[0092] The stop valve block 116 is respectively connected to the thickness control hydraulic cylinder 106 and the accumulator 125 , and is used to open or close the accumulator 125 .

[0093] In some embodiments, a hydraulic system 100 is provided in an embodiment of the present application, and the hydraulic system 100 further includes:

[0094] An oil return main line 127, the oil return main line 127 is connected to the oil tank 101;

[0095] The oil return check valve 128 is used to control the oil return main line 127 .

[0096] In this embodiment, the hydraulic system 100 further includes an oil return main line 127 and an oil return check valve 128 .

[0097] The main oil return line 127 is connected to the oil tank 101 and is a pipeline for the return oil to flow.

[0098] The oil return check valve 128 is used to ensure that the oil return main line 127 is filled with oil, avoid the presence of air in the line, and reduce the vibration of the hydraulic system 100 line.

[0099] In some embodiments, a hydraulic system 100 is provided in an embodiment of the present application, and the hydraulic system 100 further includes:

[0100] The load relief oil pipeline 129 is connected to the oil tank 101 and is used for conveying the load relief oil.

[0101] In this embodiment, the hydraulic system 100 further includes a relief oil pipeline 129 , which is connected to the oil tank 101 and is a pipeline for the relief oil to flow.

[0102] Exemplarily, the rodless cavity pipeline of the transmission side thickness control hydraulic cylinder 106 is A1, the rodless cavity pipeline of the operating side thickness control hydraulic cylinder 106 is A2, and the rod cavity pipelines of the thickness control hydraulic cylinders 106 on both sides are B.

[0103] In some embodiments, Figure 2 As shown, in an embodiment of the present application, a control method for a hydraulic system is provided, comprising:

[0104] Step S201, transmitting the hydraulic oil in the oil tank to the high-pressure filter through the first hydraulic pump group and the second hydraulic pump group;

[0105] Step S202, filtering the hydraulic oil through a high-pressure filter to obtain filtered hydraulic oil;

[0106] Step S203, after the thickness control hydraulic cylinder receives the filtered hydraulic oil, the roll gap of the rolling mill is adjusted through the thickness control hydraulic cylinder.

[0107] In this embodiment, the hydraulic system is the hydraulic system in any of the above embodiments.

[0108] The hydraulic oil in the oil tank is transmitted to the high-pressure filter through the first hydraulic pump group and the second hydraulic pump group.

[0109] The hydraulic oil is filtered through a high-pressure filter to obtain the filtered hydraulic oil. After the thickness control hydraulic cylinder receives the filtered hydraulic oil, the roll gap of the rolling mill is adjusted through the thickness control hydraulic cylinder.

[0110] The control method of the hydraulic system in this embodiment replaces the valve control system in the conventional hydraulic system with the first hydraulic pump group and the second hydraulic pump group, thereby simplifying the structure of the hydraulic system, thereby reducing the oil circulation volume of the hydraulic system, reducing the energy consumption of the hydraulic system, and improving the efficiency of the hydraulic system.

[0111] In some embodiments, a control device for a hydraulic system is proposed, the control device for the hydraulic system includes a processor and a memory, the memory stores a computer program, and when the computer program is executed by the processor, the steps of the control method for the hydraulic system in any of the above embodiments are implemented. Therefore, the control device for the hydraulic system has all the beneficial effects of the control method for the hydraulic system in any of the above embodiments, which will not be described in detail here.

[0112] In some embodiments, a readable storage medium is provided on which a program is stored. When the program is executed by a processor, the steps of the hydraulic system control method in any of the above embodiments are implemented, thereby having all the beneficial technical effects of the hydraulic system control method in any of the above embodiments.

[0113] In some embodiments, a rolling mill is provided in an embodiment of the present application, including: a hydraulic system as in any of the above embodiments, and thus has all the beneficial technical effects of the hydraulic system in any of the above embodiments, which will not be elaborated herein.

[0114] Exemplarily, the hydraulic system includes four working modes: pressing mode, roller changing mode, quick opening mode and maintenance mode. The power-on timing in the four modes is shown in Table 1.

[0115] Table 1

[0116]

[0117] (1) Press-down mode;

[0118] The pressure mode is the normal working mode of the equipment. The reversing valve is energized, the hydraulic control check valve is reversely opened, and the hydraulic system has normal working conditions. The second hydraulic pump group and the position sensor realize position closed-loop control, and the second hydraulic pump group and the pressure sensor realize pressure closed-loop control. The two modes can be switched. The electromagnetic overflow valve is energized to maintain the overflow valve function. When the mill roll gap is closed, the second hydraulic pump group supplies the pressure oil stored in the piston accumulator to the rodless chamber of the thickness control hydraulic cylinder through the high-pressure filter and the hydraulic control check valve. The set pressure of the proportional three-way pressure reducing valve is P1, and the oil in the rod chamber of the thickness control hydraulic cylinder is discharged back to the oil tank through the proportional three-way pressure reducing valve. When the mill roll gap is opened, the pressure oil stored in the piston accumulator enters the rod chamber of the thickness control hydraulic cylinder through the proportional three-way pressure reducing valve. The set pressure of the proportional three-way pressure reducing valve is P1, and the oil in the rodless chamber of the thickness control hydraulic cylinder is discharged into the piston accumulator by the second hydraulic pump group.

[0119] (2) Roller changing mode;

[0120] When the rolling mill rolls are changed, the speed of closing the roll gap of the rolling mill needs to be increased, so the set pressure of the proportional three-way pressure reducing valve is changed to P2. Other equipment and working methods are the same as the working mode.

[0121] (3) Quick-open working mode;

[0122] When the scrap steel roll gap of the rolling mill needs to be opened quickly or the calibrated roll gap of the rolling mill needs to be opened quickly, the reversing valve loses power, the hydraulic control check valve closes, the electromagnetic overflow valve is powered and switched to the unloading valve function, and the oil in the rod chamber of the thickness control hydraulic cylinder is directly unloaded back to the oil tank through the electromagnetic overflow valve, so that the thickness control hydraulic cylinder retracts quickly and the roll gap opens quickly. The set pressure of the proportional three-way pressure reducing valve is, and the working method is the same as that in the working mode.

[0123] (4) Maintenance mode;

[0124] The inspection mode is generally used during inspections, and the system needs to be drained and depressurized. Therefore, in the inspection mode, the unloading solenoid reversing valve is energized to discharge the pressure oil in the piston accumulator back to the oil tank, and the hydraulic pipeline is inspected. If the pneumatic pipeline is to be depressurized, the stop valve block needs to be used to depressurize the nitrogen.

[0125] (5) Oil replenishment operation;

[0126] Since the return oil and load relief oil of the hydraulic system return directly to the oil tank, the pressure oil stored in the piston accumulator is gradually reduced, and the piston accumulator needs to be replenished according to the inspection pressure of the pressure sensor and the detection position of the position sensor. When the detection value of the pressure sensor is lower than, the first hydraulic pump group automatically starts to replenish oil, and when the detection value of the first pressure sensor is higher than, the first hydraulic pump group automatically stops replenishing oil. When the detection position of the first position sensor is greater than the set value, the first hydraulic pump group automatically starts to replenish oil, and when the detection position of the first position sensor is less than the set value, the first hydraulic pump group automatically stops replenishing oil. There is a corresponding relationship between the pressure value of the first pressure sensor and the position value of the first position sensor. Replenishing oil according to the detection pressure value of the first pressure sensor is the main mode, and replenishing oil according to the detection position value of the first position sensor is the auxiliary mode. The main mode and the auxiliary mode can be switched for control.

[0127] (6) Nitrogen replenishment operation;

[0128] The nitrogen pressure in the nitrogen cylinder should be kept within a certain pressure range. When the detection pressure of the pressure sensor is lower than the set value P7, the system alarm prompts that nitrogen needs to be supplemented. When the detection position of the first position sensor is less than the set value, the system alarm prompts that nitrogen needs to be supplemented. Both alarms require nitrogen supplementation. To supplement nitrogen, a nitrogen charging trolley is used to supplement nitrogen to the system through the pressure measuring point of the stop valve block.

[0129] (7) Pressure setting;

[0130] Seven pressures need to be set in the thickness control hydraulic system. P1 is the set pressure of the proportional three-way pressure reducing valve in the working mode. P2 is the set pressure of the proportional three-way pressure reducing valve in the roll changing mode (P2>P1). P3 is the pressure of the nitrogen in the accumulator connected to the rod chamber of the thickness control hydraulic cylinder, which is generally set to 70-80% of the normal working pressure. P4 is the set pressure of the electromagnetic overflow valve. This pressure is generally higher than the working pressure of the rodless chamber of the thickness control hydraulic cylinder. The electromagnetic overflow valve remains normally closed in the working mode. P5 is the detection pressure of the first pressure sensor, which is used to interlock the start of the first hydraulic pump group. P6 is the detection pressure of the first pressure sensor, which is used to interlock the stop of the first hydraulic pump group. The pressure values ​​of P5 and P6 should be debugged according to the actual situation (P6>P5). P7 is the detection value of the third pressure sensor, which is used for the nitrogen filling alarm of the system.

[0131] It should be noted that in the above embodiments, the description of each embodiment has its own emphasis, and for parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0132] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-readable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-readable program code.

[0133] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded computer, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0134] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1A function specified in one or more boxes.

[0135] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0136] An embodiment of the present application further provides a computer program product, which includes computer software instructions. When the computer software instructions are executed on a processing device, the processing device executes a process of a control method for a hydraulic system.

[0137] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on the computer, the process or function according to the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website site, a computer, a server or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium can be any available medium that a computer can store or a data storage device such as a server or a data center that includes one or more available media integration. The available medium can be a magnetic medium, (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid state drive (SSD)), etc.

[0138] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0139] In the several embodiments provided in the present application, it should be understood that the disclosed devices, apparatuses and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0140] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0141] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0142] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), disk or optical disk and other media that can store program codes.

[0143] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

[0144] Although the preferred embodiments of this specification have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of this specification.

[0145] Obviously, those skilled in the art can make various changes and modifications to this specification without departing from the spirit and scope of this specification. Thus, if these modifications and variations of this specification fall within the scope of the claims of this specification and their equivalents, this specification is also intended to include these modifications and variations.

Claims

1. A hydraulic system, characterized in that: Applied to a rolling mill, the hydraulic system comprises: Oil tank, used to store hydraulic oil; a first hydraulic pump group and a second hydraulic pump group, wherein one end of the first hydraulic pump group is connected to the oil tank, and the other end of the first hydraulic pump group is connected to one end of the second hydraulic pump group; a high-pressure filter, one end of which is connected to the other end of the second hydraulic pump unit; A double-connected one-way valve group, one end of which is connected to the other end of the high-pressure filter; A thickness control hydraulic cylinder is connected to the other end of the double-connected one-way valve group and is used to adjust the roll gap of the rolling mill.

2. The hydraulic system according to claim 1, characterized in that: The hydraulic system further comprises: A pump suction port ball valve, used to isolate the oil tank and the first hydraulic pump unit; A main oil inlet pipeline, the main oil inlet pipeline is connected to the oil tank; A pump outlet non-return valve, used for isolating the hydraulic pump group and the main oil inlet pipeline; A piston accumulator connected to the thickness control hydraulic cylinder and used for storing and providing hydraulic oil inside the thickness control hydraulic cylinder; The unloading electromagnetic reversing valve is used to unload the oil in the piston accumulator and the main oil inlet pipeline back to the oil tank.

3. The hydraulic system according to claim 2, characterized in that: The hydraulic system further comprises: A first pressure sensor, used to detect the pressure of the main oil inlet pipeline; a first position sensor for detecting the position of a piston of a piston accumulator; The second pressure sensor is used to detect the pressure of the piston accumulator.

4. The hydraulic system according to claim 2, characterized in that: The hydraulic system further comprises: A nitrogen cylinder, used to store nitrogen to balance the pressure of the piston accumulator; A stop valve block, connecting the nitrogen cylinder and the piston accumulator, and used for opening or closing the nitrogen cylinder; The first ball valve is used to isolate the connection between the piston accumulator and the main oil inlet pipeline and the nitrogen cylinder.

5. The hydraulic system according to any one of claims 1 to 4, characterized in that: The hydraulic system further comprises: A hydraulically controlled one-way valve, used to isolate the second hydraulic pump group and the thickness control hydraulic cylinder; A reversing valve, used to control the hydraulically controlled one-way valve; An electromagnetic overflow valve connected to the thickness control hydraulic cylinder; A second ball valve is connected to the thickness control hydraulic cylinder and is used to isolate the thickness control hydraulic cylinder.

6. The hydraulic system according to any one of claims 1 to 4, characterized in that: The hydraulic system further comprises: a second position sensor, used to measure the piston position of the thickness control hydraulic cylinder; The third pressure sensor is used to measure the pressure data of the thickness control hydraulic cylinder.

7. The hydraulic system according to any one of claims 1 to 4, characterized in that: The hydraulic system further comprises: A proportional three-way pressure reducing valve connected to the thickness control hydraulic cylinder and used for supplying oil to the thickness control hydraulic cylinder; An accumulator for adjusting the pressure of the thickness control hydraulic cylinder; The stop valve block is respectively connected to the thickness control hydraulic cylinder and the accumulator, and is used to open or close the accumulator.

8. The hydraulic system according to any one of claims 1 to 4, characterized in that: The hydraulic system further comprises: An oil return main line, the oil return main line being connected to the oil tank; An oil return one-way valve, used to control the oil return main line; The load relief oil pipeline is connected to the oil tank and is used for conveying the load relief oil.

9. A method for controlling a hydraulic system, characterized in that: The hydraulic system is a hydraulic system according to any one of claims 1 to 8, and the method comprises: The hydraulic oil in the oil tank is transmitted to the high-pressure filter through the first hydraulic pump group and the second hydraulic pump group; Filtering the hydraulic oil through the high-pressure filter to obtain the filtered hydraulic oil; After the thickness control hydraulic cylinder receives the filtered hydraulic oil, the roll gap of the rolling mill is adjusted through the thickness control hydraulic cylinder.

10. A rolling mill, characterized in that: The rolling mill comprises: A hydraulic system as claimed in any one of claims 1 to 8.

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