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CN110259769B - Electro-hydraulic control system of 3000T liquid die forging hydraulic press and forming process - Google Patents

Electro-hydraulic control system of 3000T liquid die forging hydraulic press and forming process Download PDF

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Publication number
CN110259769B
CN110259769B CN201910446306.2A CN201910446306A CN110259769B CN 110259769 B CN110259769 B CN 110259769B CN 201910446306 A CN201910446306 A CN 201910446306A CN 110259769 B CN110259769 B CN 110259769B
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pressure
speed
liquid
proportional
sliding block
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CN110259769A (en
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曲永志
张晓艳
高晓勇
陈庚
崔金山
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Tianjin Tianduan Press Co Ltd
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Tianjin Tianduan Press Co Ltd
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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B21MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21JFORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
    • B21J9/00Forging presses
    • B21J9/10Drives for forging presses
    • B21J9/12Drives for forging presses operated by hydraulic or liquid pressure
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B21MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21JFORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
    • B21J9/00Forging presses
    • B21J9/10Drives for forging presses
    • B21J9/20Control devices specially adapted to forging presses not restricted to one of the preceding subgroups
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B21/00Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
    • F15B21/001Servomotor systems with fluidic control
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B21/00Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
    • F15B21/08Servomotor systems incorporating electrically operated control means

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • General Engineering & Computer Science (AREA)
  • Control Of Presses (AREA)
  • Forging (AREA)

Abstract

The invention discloses an electro-hydraulic control system and a forming process of a 3000T liquid die forging hydraulic press, which belong to the technical field of liquid metal forming and are characterized in that: the electro-hydraulic control system of the 3000T liquid die forging hydraulic press at least comprises: a displacement sensor for detecting the position information of the slide block; the pressure sensor is used for detecting the pressure information of the cavity of the main cylinder; and a PLC electrically connected with the displacement sensor and the pressure sensor. The invention relates to a method for realizing rapid forming of liquid aluminum liquid by adopting a PID algorithm by designing an electro-hydraulic control system of a liquid die forging hydraulic press and taking Siemens 1500 series PLC as a core element. Compared with a traditional Korea valve-controlled hydraulic forging press, the proportional cartridge valve using the atom can realize adjustable descending speed and stable speed transition, so that the production takt can be improved, and the production efficiency is also improved.

Description

Electro-hydraulic control system of 3000T liquid die forging hydraulic press and forming process
Technical Field
The invention belongs to the technical field of liquid metal forming, and particularly relates to an electro-hydraulic control system of a 3000T liquid die forging hydraulic press and a forming process.
Background
In recent years, with the rapid development of science and technology, both traditional automobiles and new energy automobiles are rapidly increased, and with the continuous improvement of the living standard of human beings, the demand of the market for automobiles is more and more large, so that the development of the automobile industry is imperative. With the gradual development of the automobile industry, the demand of the light wheel made of aluminum alloy is more and more, and therefore, the design of an electro-hydraulic control system of an effective 3000T liquid die forging hydraulic press for producing the aluminum wheel and a forming process are more and more important.
Disclosure of Invention
The invention provides an electro-hydraulic control system of a 3000T liquid die forging hydraulic press and a forming process aiming at the technical problems in the prior art, and the invention provides a method for realizing the rapid forming of liquid aluminum liquid by adopting a PID algorithm by designing the electro-hydraulic control system of the liquid die forging hydraulic press and taking Siemens 1500 series PLC as a core element. Compared with a traditional Korea valve-controlled hydraulic forging press, the proportional cartridge valve using the atom can realize adjustable descending speed and stable speed transition, so that the production takt can be improved, and the production efficiency is also improved.
The technical scheme adopted by the invention for solving the technical problems in the prior art is as follows:
the first invention of the invention provides an electrohydraulic control system of a 3000T liquid die forging hydraulic press, which at least comprises:
the displacement sensor is used for detecting the position information of the sliding block;
the pressure sensor is used for detecting the pressure information of the cavity of the main cylinder;
and the PLC is electrically connected with the PID controller, the displacement sensor and the pressure sensor.
The second invention aims to provide a forming process of an electro-hydraulic control system of a 3000T liquid die forging hydraulic press, which at least comprises the following steps:
step one, in a rapid descending stage of the sliding block, the self gravity of the sliding block is used as power, the oil discharge speed of a return cavity of the side cylinder is changed by controlling the size of an atom proportional valve opening on the side of the return cavity of the side cylinder through a PLC (programmable logic controller), and the larger the atom proportional valve opening is, the faster the oil discharge speed of the return cavity is and the faster the descending speed of the sliding block is;
step two, the slide block worker enters a descending stage, the upper die is close to the position of liquid aluminum liquid, the aluminum liquid is filled in the whole die cavity when the slide block worker descends, and the descending speed of the slide block is reduced to 6-9 mm/s; in the process, the descending speed of the sliding block is adjusted by changing the opening of the atom proportional valve, and meanwhile, the main pump group supplies oil to the main cylinder;
step three, in the descending stage of slide block pressing, the speed is required to be stable and within the range of 0-5 mm/s; closing the atom proportional valve, and forming back pressure in the return cavity by the back pressure valve at the return cavity side of the side cylinder to support the sliding block so that the sliding block does not slide downwards under the self gravity state; the speed of the slide block is only provided by the main pump group, and for speed control, the oil discharge amount of the proportional pump is changed through a speed closed-loop algorithm to achieve the purpose of stabilizing the speed;
step four, in a downlink pressurization stage, aiming at 6061 series materials, considering the internal strain reaction of an aluminum alloy material, when liquid aluminum liquid is pressed, slowly pressurizing before 1000T, and quickly pressurizing to 2500T after 1000T, and in the process of slowly pressurizing, on the premise of meeting the oil compression amount of a system and the maximum power of a proportional constant-power pump, reducing the oil discharge amount of the proportional pump, and relatively reducing the pressure rise rate to realize slow pressurization; in the rapid pressurization process, the oil discharge amount of the proportional constant-power pump is increased, the pressure increase rate of the system is improved, but the problem of the pressure variable point of the proportional constant-power pump needs to be considered at the moment, when the constant power of the proportional pump is achieved, the flow rate and the pressure are in an inverse proportional relation, and the flow rate is relatively reduced while the pressure is increased; when the pressure is close to the target pressure, the pressure is continuously increased by adopting the small flow rate of the cut single pump, so that the overshoot of the pressure is ensured to be within a reasonable range, and the pressure is maintained to be stable;
and step five, in the pressure maintaining stage, the pressure is continuously increased by using the small flow of a single proportional pump, and in order to ensure the stability of the pressure in the pressure maintaining process, the opening amount of a proportional overflow valve is required to be changed by a pressure closed-loop algorithm.
The invention has the advantages and positive effects that:
by adopting the technical scheme, the invention realizes the rapid forming of the liquid aluminum liquid by designing the electro-hydraulic control system of the liquid die forging hydraulic press and adopting a PID algorithm by taking Siemens 1500 series PLC as a core element. Compared with a traditional Korea valve-controlled hydraulic forging press, the proportional cartridge valve using the atom can realize adjustable descending speed and stable speed transition, so that the production takt can be improved, and the production efficiency can be improved; in the invention, the use of the atom proportional cartridge valve can realize quick descending and speed-adjustable lifting point with stable speed transition; compared with the traditional method for realizing rapid pressurization by adopting an energy accumulator in Korea, the control method in the fourth step can realize controllable pressurization rate, and compared with the control method, the method not only improves the performance of equipment, but also improves the production efficiency to a certain extent; many of the actions of other equipment in a liquid hub forging line may be in parallel with the hydraulic press, with no room for compression. For the korean traditional valve control system, the tact time of liquid forging can be increased by shortening the time for rapidly descending the slide block and the time for pressurizing, and at the same time, the down time of the equipment can be prolonged, the maintenance time of the equipment can be increased, and the service life of the equipment can be prolonged.
Description of the drawings:
FIG. 1 is a diagram of a process shaping control method of a third pressing stage of a hydraulic liquid die forging press;
fig. 2 is a diagram of a process forming control method of a fifth pressing stage of a hydraulic die forging press.
Detailed Description
In order to further understand the contents, features and effects of the present invention, the following embodiments are illustrated and described in detail with reference to the accompanying drawings:
referring to figures 1 and 2 of the drawings,
the invention discloses an electro-hydraulic control system of a 3000T liquid die forging hydraulic press, which comprises:
the displacement sensor is used for detecting the position information of the sliding block;
the pressure sensor is used for detecting the pressure information of the cavity of the main cylinder;
and the PLC is electrically connected with the PID controller, the displacement sensor and the pressure sensor.
A forming process of an electro-hydraulic control system of a 3000T liquid die forging hydraulic press comprises the following steps:
the first step is a rapid descending stage of the slide block. At this stage, the gravity of the sliding block is used as power, the oil discharge speed of the return cavity of the side cylinder can be changed by controlling the size of the opening of the atom proportional valve at the return cavity side of the side cylinder through the PLC (the larger the opening of the atom proportional valve is, the faster the oil discharge speed of the return cavity is, the faster the sliding block moves downwards), and the sliding block needs to move downwards quickly so that the upper die is close to the aluminum liquid quickly.
And step two is a slide block working progress descending stage. At this stage, the upper die is close to the position of liquid aluminum liquid, the aluminum liquid needs to be filled in the whole die cavity when the upper die moves downwards, the speed needs to be ensured not to be too high, the aluminum liquid is prevented from splashing, and the descending speed of the sliding block needs to be reduced to about 6-9 mm/s. In the process, the descending speed of the sliding block is still adjusted by changing the opening of the atom proportional valve, and meanwhile, the main pump group is required to supply oil to the main cylinder, so that the phenomenon of pause caused by insufficient oil supply in the process of converting the working process into the pressing descending process is prevented.
And step three, a slide block pressing descending stage. At this stage, the speed is required to be stable and adjustable within the range of 0-5 mm/s. This requires closing the atom proportional valve, and the back pressure valve on the return chamber side of the side cylinder will create back pressure in the return chamber to hold the slide against falling under its own weight. The purpose of this is to achieve that the speed of the slide is provided only by the main pumping group, so that the speed is accurately controlled. For speed control, because the speed is attenuated due to the compression of oil in the descending process of the sliding block, in order to reduce the speed attenuation in the descending process, the oil discharge amount of the proportional pump needs to be changed through a speed closed-loop algorithm to achieve the purpose of stable speed.
The fourth step is a descending pressurization stage. For 6061 series materials, considering the internal strain reaction of the aluminum alloy material, when liquid aluminum liquid is pressed, the pressure is slowly increased before 1000T, and the pressure is quickly increased to 2500T after 1000T, so that the organizational structure of the product is better. In view of the process requirements, in the process of slow pressurization, on the premise of meeting the oil compression amount of a system and the maximum power of a proportional constant-power pump, the oil discharge amount of the proportional pump is reduced, and the pressure rise rate is relatively reduced, so that the slow pressurization is realized. In the process of rapid pressurization, the oil discharge amount of the proportional constant-power pump is increased, and the increase rate of the system pressure is improved, but the problem of the pressure variable point of the proportional constant-power pump is considered at the moment, when the constant power of the proportional pump is achieved, the flow rate and the pressure are in an inverse proportional relation, and the flow rate is relatively reduced while the pressure is increased. When the pressure is close to the target pressure, the pressure is continuously increased by adopting the small flow rate of the cut single pump, the overshoot of the pressure is ensured to be in a reasonable range, and the pressure stability is maintained.
And step five is a pressure maintaining stage. At this stage, the pressure is continuously increased with the small flow rate of the single proportional pump, and in order to ensure the stability of the pressure in the pressure maintaining process, the opening amount of the proportional overflow valve is changed by a pressure closed-loop algorithm to achieve the purpose of speed stability.
The embodiments of the present invention have been described in detail, but the description is only for the preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made within the scope of the present invention shall fall within the scope of the present invention.

Claims (1)

1. A forming process of an electro-hydraulic control system of a 3000T liquid die forging hydraulic press is characterized in that:
the electro-hydraulic control system of the 3000T liquid die forging hydraulic press comprises:
the displacement sensor is used for detecting the position information of the sliding block;
the pressure sensor is used for detecting the pressure information of the cavity of the main cylinder;
and PLC electrically connected with the displacement sensor and the pressure sensor;
the forming process at least comprises the following steps:
step one, in a rapid descending stage of the sliding block, the self gravity of the sliding block is used as power, the oil discharge speed of a return cavity of the side cylinder is changed by controlling the size of an atom proportional valve opening on the side of the return cavity of the side cylinder through a PLC (programmable logic controller), and the larger the atom proportional valve opening is, the faster the oil discharge speed of the return cavity is and the faster the descending speed of the sliding block is;
step two, the slide block worker enters a descending stage, the upper die is close to the position of liquid aluminum liquid, the aluminum liquid is filled in the whole die cavity when the slide block worker descends, and the descending speed of the slide block is reduced to 6-9 mm/s; in the process, the descending speed of the sliding block is adjusted by changing the opening of the atom proportional valve, and meanwhile, the main pump group supplies oil to the main cylinder;
step three, in the descending stage of slide block pressing, the speed is required to be stable and within the range of 0-5 mm/s; closing the atom proportional valve, and forming back pressure in the return cavity by the back pressure valve at the return cavity side of the side cylinder to support the sliding block so that the sliding block does not slide downwards under the self gravity state; the speed of the sliding block is only provided by the main pump group, and for speed control, the oil discharge amount of the proportional constant-power pump is changed through a speed closed-loop algorithm to achieve the purpose of stabilizing the speed;
step four, in a downlink pressurization stage, aiming at 6061 series materials, considering the internal strain reaction of an aluminum alloy material, when liquid aluminum liquid is pressed, slowly pressurizing before 1000T, and quickly pressurizing to 2500T after 1000T, and in the process of slowly pressurizing, on the premise of meeting the oil compression amount of a system and the maximum power of a proportional constant power pump, reducing the oil discharge amount of the proportional constant power pump, and relatively reducing the pressure rise rate to realize slow pressurization; in the rapid pressurization process, the oil discharge amount of the proportional constant-power pump is increased, the pressure increase rate of the system is improved, but the problem of the pressure variable point of the proportional constant-power pump is considered at the moment, when the constant power of the proportional constant-power pump is achieved, the flow rate and the pressure are in an inverse proportional relation, and the flow rate is relatively reduced while the pressure is increased; when the pressure is close to the target pressure, the pressure is continuously increased by adopting the small flow rate of the cut single pump, so that the overshoot of the pressure is ensured to be within a reasonable range, and the pressure is maintained to be stable;
and step five, in the pressure maintaining stage, the pressure is continuously increased at a low flow rate of a single proportional constant-power pump, and in order to ensure the stability of the pressure in the pressure maintaining process, the opening amount of a proportional overflow valve is required to be changed through a pressure closed-loop algorithm.
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Publication number Priority date Publication date Assignee Title
CN111604451B (en) * 2020-05-20 2022-06-17 天津天锻航空科技有限公司 Control method and control system for hot forming process of high-precision forging hydraulic press
CN113351817A (en) * 2021-04-30 2021-09-07 天津市天锻压力机有限公司 Flexible control method of forging press
CN113953485B (en) * 2021-09-17 2023-03-14 天津市天锻压力机有限公司 Liquid die forging forming process method based on boost rate control
CN114769491B (en) * 2022-04-29 2024-06-04 中国重型机械研究院股份公司 Intelligent speed regulation control system and method for large die forging press

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