阅读说明：本技术 一种基于极薄钢板辊压式淬火机的液压伺服系统 (Hydraulic servo system based on extremely thin steel sheet roll-in formula quenching machine ) 是由 韩毅 付天亮 王昭东 田勇 李勇 高俊国 于 2019-09-05 设计创作，主要内容包括：本发明公开了一种基于极薄钢板辊压式淬火机的液压伺服系统,属于钢板热处理区域的技术领域。由液压站本体,主供油管路,背压供油管路,主回油管路,控制油卸油管路五大部分组成。所述液压系统通过电磁伺服阀与多类阀的配合使用及背压供油管路与控制油回油管路的特别设计,满足了辊压式淬火机对执行液压缸定位精度高,运行快速稳定,响应时间快的要求,具备生产极薄淬火钢板时根据压力及位置反馈对液压缸行程进行快速平稳调节能力。本发明满足了辊压式淬火机的。(The invention discloses a hydraulic servo system based on an extremely thin steel plate rolling type quenching machine, and belongs to the technical field of steel plate heat treatment areas. The hydraulic station consists of five parts, namely a hydraulic station body, a main oil supply pipeline, a back pressure oil supply pipeline, a main oil return pipeline and a control oil discharge pipeline. The hydraulic system meets the requirements of a roll-press type quenching machine on high positioning precision, quick and stable operation and quick response time of an execution hydraulic cylinder through the matching use of the electromagnetic servo valve and the valves and the special design of the back pressure oil supply pipeline and the control oil return pipeline, and has the capability of quickly and stably adjusting the stroke of the hydraulic cylinder according to pressure and position feedback during the production of an extremely-thin quenching steel plate. The invention meets the requirements of a roll-type quenching machine.)

1. A hydraulic servo system based on an extremely thin steel plate roll-pressing type quenching machine is characterized by comprising a hydraulic station body, a main oil supply pipeline, a back pressure oil supply pipeline, a main oil return pipeline and a control oil discharge pipeline;

the hydraulic station body comprises an oil tank (1), a hydraulic variable pump (2), a circulating pump (3), an electromagnetic control overflow valve A (4), a high-pressure filter (5), a circulating filter (13) and a plate heat exchanger (14); the oil tank (1) is respectively connected with a hydraulic variable pump (2) and a circulating pump (3), the hydraulic variable pump (2) is sequentially connected with an electromagnetic control overflow valve A (4) and a high-pressure filter (5), and the circulating pump (3) is sequentially connected with a circulating filter (13) and a plate heat exchanger (14); the hydraulic variable pump (2) sucks hydraulic oil from the oil tank (1), and the high-pressure oil is conveyed to a main oil supply pipeline and a back pressure oil supply pipeline through an electromagnetic control overflow valve A (4) and a high-pressure filter (5) to drive a hydraulic actuating mechanism to act; the circulating pump (3) sucks hydraulic oil from the oil tank (1), the oil is cooled by the plate heat exchanger (14), and is filtered by the circulating filter (13) and then returns to the oil tank (1), so that the cleanliness of the oil in the oil tank (1) is ensured to meet the use requirement, and the temperature of the oil is between 35 ℃ and 45 ℃;

The main oil supply pipeline comprises a two-position four-way reversing valve A (9), a hydraulic control one-way valve A (10), an energy accumulator A (17), a servo oil cylinder (20) and an electromagnetic servo valve (25); the two-position four-way reversing valve A (9) is respectively connected with the high-pressure filter (5) and the hydraulic control one-way valve A (10), the hydraulic control one-way valve A (10) is connected with the electromagnetic servo valve (25), the electromagnetic servo valve (25) is respectively connected with the PLC and the servo oil cylinder (20), and the energy accumulator A (17) is connected with the pipeline in series; when the system needs a main oil supply pipeline to provide pressure oil, the two-position four-way reversing valve A (9) is electrified, the hydraulic control one-way valve A (10) is opened, the pressure oil flows to the electromagnetic servo valve (25) through the pipeline, and the position of the valve core of the servo valve is controlled through an electric signal given by the PLC, so that the action of the servo oil cylinder (20) is controlled; the energy accumulator A (17) is filled with nitrogen with certain pressure, so that the effect of ensuring the pressure and flow stability of the main oil supply pipeline is achieved;

The back pressure oil supply pipeline comprises a pressure reducing valve A (6), a pressure reducing valve B (7), a three-position four-way reversing valve (8), an energy accumulator B (18) and an energy accumulator C (19); the high-pressure filter (5) is connected with an energy accumulator A (17), an energy accumulator B (18) and an energy accumulator C (19) through a pressure reducing valve A (6) and a pressure reducing valve B (7), and the pressure reducing valve B (7) is also connected with a three-position four-way reversing valve (8); when the hydraulic variable pump (2) outputs a certain pressure, the pressure is reduced through the pressure reducing valve A (6) and is used for providing back pressure when the servo oil cylinder (20) descends, so that the stability and the positioning accuracy of the servo oil cylinder (20) in the lifting process are improved, the impact is reduced, and the equipment is protected; when the hydraulic variable pump (2) outputs a certain pressure, the pressure is reduced through the pressure reducing valve A (6) and the pressure reducing valve B (7) in a double mode and is used as an oil supply pipeline when the servo oil cylinder (20) ascends, the frame lifting power is met, meanwhile, the stability and the positioning precision of the servo oil cylinder (20) in the lifting process are improved, the impact is reduced, and 2 different pressures provided by the back pressure oil supply pipeline are switched through the three-position four-way reversing valve (8) so as to meet different working states;

The control oil unloading pipeline comprises a regulating valve (29), an oil unloading branch pipe A (30) connected with 3 hydraulic control one-way valves, an oil unloading branch pipe B (31) and an oil unloading branch pipe C (32); when the hydraulic control one-way valve A (10), the hydraulic control one-way valve B (21) and the hydraulic control one-way valve C (27) stop working, the two-position four-way reversing valve A (9), the two-position four-way reversing valve B (22) and the two-position four-way reversing valve C (28) are switched to stop positions, and control oil enters each oil unloading branch pipe through each two-position four-way reversing valve and flows back to the oil tank (1) quickly; the regulating valve (29) has the function of sealing the pipeline when the pipeline is in fault, so that the maintenance is convenient;

The main oil return pipeline comprises an oil return filter (11), a one-way valve (33) and a regulating valve B (34) which are connected in sequence; the check valve (33) prevents part of oil from flowing back due to turbulence generated when the oil in the pipeline flows through the oil return filter (11), and the oil return rate is reduced; the oil return filter (11) plays a role in removing impurities such as scrap iron and the like in the returned oil and ensuring the cleanness of the oil; the returned oil in the whole hydraulic system quickly returns to the oil tank through the one-way valve (33) and the return oil filter (11).

2. The hydraulic servo system of the extremely thin steel plate rolling type quenching machine as claimed in claim 1, wherein an overflow valve (12) is arranged between the circulating pump (3) and the circulating filter (13).

3. The hydraulic servo system of the extremely thin steel plate rolling quenching machine as claimed in claim 1 or 2, wherein the electromagnetic control overflow valve B (26) is connected with a hydraulic control one-way valve C (27), when the pump is started, the electromagnetic control overflow valve B (26) is opened, oil completely overflows back to the oil tank, no-load starting of the pump is ensured, after 10 seconds, the electromagnetic control overflow valve B (26) is closed, and the system is used as a system safety valve to prevent overpressure of the system.

Technical Field

The invention relates to the technical field of steel plate heat treatment areas, in particular to the technical field of equipment of a hydraulic control system of a sheet quenching machine.

Background

In a steel plate heat treatment workshop, a finished steel plate is heated by a heating furnace and then needs to be quenched and cooled to improve the strength and the performance of the plate according to the requirements of the process flow, and a quenching machine is a core device for completing the quenching and cooling process.

The quenching machine commonly used in the industry at present is a roller type quenching machine, as shown in figure 1, the quenching machine mainly comprises an electric lifter, a hydraulic cylinder, a movable frame, an upper roller way, a nozzle and the like, the hot steel plate is quenched by controlling the water quantity and the water pressure of the nozzle, a roller gap is controlled by the electric lifter, and a plate type is controlled in an auxiliary manner, wherein the hydraulic cylinder of the upper frame only plays a role in controlling the lifting of the frame and buffering and damping, and when the quenching machine is used for producing quenching plates with the thickness of 4mm or less, the quality of finished products and the plate type cannot meet the process requirements easily.

in order to break the bottleneck of the production of the quenching steel plates in China, a rolling and continuous rolling automation national key laboratory at the northeast university develops a rolling quenching machine for producing ultrathin quenching plates, as shown in fig. 2, the rolling quenching machine mainly comprises a servo hydraulic cylinder, an upper frame, a roller way, a nozzle and the like, and compared with an old type rolling quenching machine, the rolling quenching machine has higher requirements on a hydraulic system and is mainly expressed in the following three aspects:

1. There is no electric lifting system, and the lifting function is completely realized by a hydraulic system.

2. The roll gap is controlled accurately, and the positioning error of the hydraulic cylinder is less than or equal to +/-0.1 mm

3. in the process of producing the quenching plate, the position of the oil cylinder is quickly adjusted according to the plate shape change, and the response time is less than or equal to 100ms

In order to meet the requirements, a high-precision quick-response hydraulic servo system of an ultrathin plate rolling type quenching machine is researched and developed in a rolling and continuous rolling automation national key laboratory of northeast university.

Patent CN101338357 discloses a high-precision synchronous control system for hydraulic multi-cylinder of a roller quenching machine, which reduces the workload of manual adjustment in the debugging process of a hydraulic system by adopting a hydraulic synchronous motor to cooperate with a control loop of a flow compensation valve for compensation, improves the control precision, and greatly improves the efficiency. The system is a hydraulic control system based on a transmission roller type quenching machine, does not adopt hydraulic servo control, does not achieve the effects of high precision and quick response, and is greatly different from the system.

Patent CN201210509964.X provides a quenching hydraulic system of a full hydraulic gear quenching machine, the system is based on the gear quenching machine, the gear quenching machine is mainly used in the machining industry, the quenching machine and the equipment applied by the invention, namely a roll-pressing type quenching machine belong to two industries, the system does not adopt hydraulic servo control, the effects of high precision and quick response are not achieved, and the invention is greatly different from the invention.

Disclosure of Invention

The invention aims to provide a novel hydraulic servo system for an ultrathin plate rolling type quenching machine, which is characterized by high positioning precision of an execution hydraulic cylinder, quick and stable operation and quick response time, and has the capability of quickly and stably adjusting the stroke of the hydraulic cylinder according to pressure and position feedback during production of an ultrathin quenching plate.

The technical scheme of the invention is as follows:

A hydraulic servo system based on an extremely thin steel plate roll-pressing type quenching machine comprises a hydraulic station body, a main oil supply pipeline, a back pressure oil supply pipeline, a main oil return pipeline and a control oil discharge pipeline;

the hydraulic station body comprises an oil tank 1, a hydraulic variable pump 2, a circulating pump 3, an electromagnetic control overflow valve A4, a high-pressure filter 5, a circulating filter 13 and a plate heat exchanger 14; the oil tank 1 is respectively connected with a hydraulic variable pump 2 and a circulating pump 3, the hydraulic variable pump 2 is sequentially connected with an electromagnetic control overflow valve A4 and a high-pressure filter 5, and the circulating pump 3 is sequentially connected with a circulating filter 13 and a plate heat exchanger 14; the hydraulic variable pump 2 sucks hydraulic oil from the oil tank 1, and high-pressure oil is conveyed to a main oil supply pipeline and a back pressure oil supply pipeline through an electromagnetic control overflow valve A4 and a high-pressure filter 5 to drive a hydraulic actuating mechanism to act; the circulating pump 3 absorbs hydraulic oil from the oil tank 1, the oil is cooled by the plate heat exchanger 14, and is filtered by the circulating filter 13 and then returns to the oil tank 1, so that the cleanness of the oil in the oil tank 1 is ensured to meet the use requirement, and the temperature of the oil is between 35 ℃ and 45 ℃.

An overflow valve 12 is arranged between the circulating pump 3 and the circulating filter 13.

The main oil supply pipeline comprises a two-position four-way reversing valve A9, a hydraulic control one-way valve A10, an energy accumulator A17, a servo oil cylinder 20 and an electromagnetic servo valve 25; the two-position four-way reversing valve A9 is respectively connected with the high-pressure filter 5 and the hydraulic control one-way valve A10, the hydraulic control one-way valve A10 is connected with the electromagnetic servo valve 25, the electromagnetic servo valve 25 is respectively connected with the PLC and the servo oil cylinder 20, and the energy accumulator A17 is connected with a pipeline in series; when the system needs the main oil supply pipeline to provide pressure oil, the two-position four-way reversing valve A9 is powered on, the hydraulic control one-way valve A10 is opened, the pressure oil flows to the electromagnetic servo valve 25 through the pipeline, and the position of the valve core of the servo valve is controlled through an electric signal given by the PLC, so that the action of the servo oil cylinder 20 is controlled; the energy accumulator A17 is filled with nitrogen with certain pressure, so that the effect of ensuring the pressure and flow stability of the main oil supply pipeline is achieved;

The back pressure oil supply pipeline comprises a pressure reducing valve A6, a pressure reducing valve B7, a three-position four-way reversing valve 8, an accumulator B18 and an accumulator C19; the high-pressure filter 5 is connected with an energy accumulator A17, an energy accumulator B18 and an energy accumulator C19 through a pressure reducing valve A6 and a pressure reducing valve B7, and the pressure reducing valve B7 is also connected with a three-position four-way reversing valve 8; when the hydraulic variable pump 2 outputs a certain pressure, the pressure is reduced through the pressure reducing valve A6, and the pressure is used for providing back pressure when the servo oil cylinder 20 descends, so that the stability and the positioning precision of the servo oil cylinder 20 in the lifting process are improved, the impact is reduced, and the equipment is protected; when the hydraulic variable pump 2 outputs a certain pressure, the pressure is reduced through the pressure reducing valve A6 and the pressure reducing valve B7 in a double mode and is used as an oil supply pipeline when the servo oil cylinder 20 ascends, the frame lifting power is met, meanwhile, the stability and the positioning precision in the lifting process of the servo oil cylinder 20 are improved, the impact is reduced, and 2 different pressures provided by a back pressure oil supply pipeline are switched through the three-position four-way reversing valve 8 so as to meet different working states;

The control oil unloading pipeline comprises a regulating valve 29, an oil unloading branch pipe A30 connected with 3 hydraulic control one-way valves, an oil unloading branch pipe B31 and an oil unloading branch pipe C32; when the hydraulic control one-way valve A10, the hydraulic control one-way valve B21 and the hydraulic control one-way valve C27 stop working, the two-position four-way reversing valve A9, the two-position four-way reversing valve B22 and the two-position four-way reversing valve C28 are switched to stop positions, and control oil enters each oil unloading branch pipe through each two-position four-way reversing valve and flows back to the oil tank 1 quickly; the regulating valve 29 can close the pipeline when the pipeline is in failure, and is convenient to maintain.

The main oil return pipeline comprises an oil return filter 11, a one-way valve 33 and a regulating valve B34 which are connected in sequence; the check valve 33 prevents part of the oil from flowing back due to turbulence generated when the oil in the pipeline flows through the oil return filter 11, and reduces the oil return rate. The oil return filter 11 plays a role in removing impurities such as scrap iron and the like in the returned oil and ensuring cleanness of the oil. The return oil in the whole hydraulic system quickly returns to the oil tank through the check valve 33 and the return oil filter 11.

The energy accumulator A17 is filled with nitrogen with 10Mpa pressure; the energy accumulator B18 and the energy accumulator C19 are respectively filled with nitrogen with 6Mpa and 3.5Mpa pressure, and play a role in ensuring the pressure and flow stability of a back pressure oil supply pipeline.

The electromagnetic control overflow valve B26 is connected with a hydraulic control check valve C27, when the pump is started, the electromagnetic control overflow valve B26 is opened, oil completely overflows back to the oil tank, and the no-load starting of the pump is ensured. After 10 seconds of delay, the electromagnetic control overflow valve B26 is closed and used as a system safety valve to prevent the overpressure of the system.

The invention has the beneficial effects that:

(1) After the device is put into use, the functional precision and the reliability completely meet the process requirements of producing a quenching plate with the thickness of 4mm by using a novel roll-pressing type quenching machine, and no hydraulic system fault occurs in the production after debugging.

(2) Because the self weight of the upper frame of the roll-type quenching machine is large, the descending speed of the oil cylinder is difficult to control stably, and a back pressure oil supply pipeline is specially designed to ensure the stable operation of the oil cylinder in the ascending and descending process. When the hydraulic cylinder is required to be lifted, different pressure differences are obtained on two sides of the piston of the oil cylinder by controlling the electromagnetic servo valve and the electromagnetic directional valve on the backpressure oil supply pipeline, so that the lifting and descending processes of the oil cylinder are stable, the positioning is accurate, the impact is small, and the damage to equipment is minimized.

(3) because the roll-pressing type quenching machine has extremely high requirement on the response speed of the hydraulic system, a control oil return pipeline is specially designed to ensure that the control oil is quickly discharged, a hydraulic control one-way valve is quickly closed, and the response time of the system is shortened. During normal production, the actual working position of the oil cylinder is detected in real time through the pressure and position sensor, the collected electric signals are fed back to the PLC, the electric signals are given out after program operation, the hydraulic control one-way valve is controlled to be opened quickly, oil liquid flows, meanwhile, the servo valve adjusts the position and the pressure of the oil cylinder in real time, after adjustment is finished, control oil is discharged quickly through the control oil return pipeline, the hydraulic control one-way valve is closed, and the oil cylinder stops at a required position.

Drawings

FIG. 1 is a schematic diagram of a roller quenching machine.

Fig. 2 is a schematic structural view of a roll quenching machine.

Fig. 3 is a schematic diagram of the principle of a single set of valve stations.

Fig. 4 is a schematic diagram of the principle of the hydraulic station.

in the figure: 1, an oil tank; 2 a hydraulic variable pump; 3, a circulating pump; 4, electromagnetically controlling the overflow valve A; 5, a high-pressure filter; 6, a pressure reducing valve A; 7, a pressure reducing valve B; 8, a three-position four-way reversing valve; 9, a two-position four-way reversing valve A; 10 hydraulic control one-way valve A; 11 return oil filter; 12 an overflow valve; 13 circulating filter; 14 a plate heat exchanger; 15 servo hydraulic cylinders; 16 an upper frame; 17 an accumulator a; 18 an accumulator B; 19 an accumulator C; 20 servo oil cylinders; 21, a hydraulic control one-way valve B; 22 a two-position four-way reversing valve B; 23 roller bed; 24, a nozzle A; 25 an electromagnetic servo valve; 26 an electromagnetic control overflow valve B; 27 hydraulic control one-way valve C; 28, a two-position four-way reversing valve C; 29 regulating valve A; 30 oil discharge branch pipes A; 31 an oil discharge branch pipe B; 32 oil discharge branch pipes C; 33 a one-way valve; 34 regulating valve B; 35 an electric elevator; 36 hydraulic cylinders; 37 moving the frame; 38, feeding the mixture to a roller way; 39, nozzle B.

Detailed Description

The following further describes a specific embodiment of a high-precision quick-response hydraulic servo system based on an extremely-thin steel plate roll-type quenching machine with reference to the accompanying drawings. The working principle of the hydraulic servo system is as follows:

When the electric control program gives a descending instruction of the servo oil cylinder 20, the electromagnet C above the electromagnetic servo valve 25 in the figure 4 is electrified, the port P is communicated with the port A, the hydraulic control one-way valve A10 in the figure 3 is opened, and hydraulic oil in the main oil supply pipeline enters the cavity B of the servo oil cylinder 20 in the figure 4. Meanwhile, an electromagnet C on the left side of the three-position four-way reversing valve 8 of the backpressure oil supply pipeline in the graph 3 is electrified, a port P is communicated with a port A, a hydraulic control one-way valve B21 in the graph 4 is opened, and 10Mpa oil of the backpressure oil supply pipeline is reduced to 6Mpa through a reducing valve A6 in the graph 3 and enters a cavity B of the servo oil cylinder 20. Because the pressure of the main oil supply pipeline is 10Mpa higher than that of the back pressure oil supply pipeline is 6Mpa, the oil cylinder piston stably descends to a specified position by the upper frame 16, the roller way 23, the nozzle A24 and other mechanisms in the graph 2 under the action of pressure difference. Then the PLC sends out a signal that the oil cylinder stops descending, meanwhile, the electromagnetic servo valve 25 in the figure 4 returns to the middle position, the main oil supply pipeline is not communicated with the oil cylinder, meanwhile, the back pressure oil supply pipeline three-position four-way reversing valve 8 in the figure 3 returns to the middle position, the pilot-controlled check valve B21 in the figure 4 controls oil to be quickly discharged to the pilot-controlled oil return pipeline through the oil discharge branch pipe B31, the pilot-controlled check valve A10 in the figure 3 controls oil to be quickly discharged to the pilot-controlled oil return pipeline through the oil discharge branch pipe A30, the pilot-controlled check valve A10 and the pilot-controlled check valve B21 are closed, the back pressure oil supply pipeline is not communicated with the servo oil cylinder 20.

When an electric control program gives a cylinder lifting instruction, an electromagnet D of the electromagnetic servo valve 25 in the figure 4 is electrified, a port T is communicated with a port A, a hydraulic control one-way valve C27 is opened, and a cavity B of the servo cylinder 20 is communicated with a main oil return pipeline. Meanwhile, an electromagnet D of the three-position four-way reversing valve 8 of the backpressure oil supply pipeline in the graph 3 is electrified, an opening A is communicated with an opening T, 10Mpa oil in the backpressure oil supply pipeline passes through a pressure reducing valve A6 in the graph 3, a pressure reducing valve B7 is reduced to 3.5Mpa, a hydraulic control one-way valve B21 in the graph 4 is opened, and the oil enters an oil cylinder A cavity. The pressure of a main oil return pipeline is 0, the pressure of an A cavity of the oil cylinder is 0, the pressure of a B cavity of the oil cylinder is 3.5Mpa, and an oil cylinder piston drives the upper frame 16, the roller way 23, the nozzle 24 and other mechanisms in the diagram 2 to stably rise to the designated positions under the pressure difference of 3.5 Mpa. Then the PLC sends out a signal that the oil cylinder stops rising, the electromagnetic servo valve 25 returns to the middle position in the graph 4, the main oil return pipeline is not communicated with the oil cylinder, meanwhile, the back pressure oil supply pipeline three-position four-way reversing valve 8 returns to the middle position in the graph 3, the hydraulic control one-way valve B21 and the hydraulic control one-way valve C27 in the graph 4 control oil to be quickly discharged through the hydraulic control oil discharge branch pipe B31 and the oil discharge branch pipe C32, the hydraulic control one-way valve B21 and the hydraulic control one-way valve C27 are closed, the back pressure oil supply pipeline and the main oil return pipeline are not communicated with the oil cylinder, and.

When a steel plate is produced, the internal organization of the hot steel plate is changed rapidly under the action of cooling water, the steel plate is deformed elastically and plastically by internal stress, the stress generated by the deformation of the steel plate acts on an upper roller way of a roller type quenching machine, the stroke and the pressure of a hydraulic cylinder are changed, a displacement sensor and a pressure sensor of a servo hydraulic cylinder feed back detected signals to a PLC (programmable logic controller), the PLC gives instructions according to a set program, and the oil pressure and the oil cylinder position are adjusted to specified values required by the process through a servo valve.