Energy-saving coil loading and unloading trolley hydraulic system

Abstract

The utility model discloses an energy-saving hydraulic system of a coil loading and unloading trolley. The system comprises a hydraulic cylinder and a hydraulic control system. The hydraulic cylinder comprises a piston rod, a cylinder body and a plunger cover to form a first hydraulic cavity, a second hydraulic cavity and a third hydraulic cavity, and the effective area of the first hydraulic cavity is larger than that of the third hydraulic cavity. The hydraulic control system comprises a high-pressure pump source, a low-pressure pump source, a control valve set, a high-pressure energy accumulator and a low-pressure energy accumulator, and the high-pressure oil way and the low-pressure oil way switch oil supply or potential energy recovery through the control valve set. And the control valve group realizes on-off control of the hydraulic cavity and the oil path. The system monitors the state through a pressure sensor and a displacement sensor, a safety valve relieves pressure, and a high-low pressure pump is a servo motor driving gear pump. The using method comprises the five states of static, jacking recoiling, empty load rising, recoiling descending and empty load descending, oil ways are intelligently switched, and descending potential energy is recycled to the low-pressure energy accumulator. By optimizing the structure and the control logic, the energy consumption and the installed power are reduced, the energy recovery is realized, and the efficiency is improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of hydraulic control technology relates to a kind of energy-saving type unloading and loading coil trolley hydraulic system, suitable for the unloading and loading operation on the strip steel production line in metallurgical industry. BACKGROUND

[0002] In the metallurgical industry, various production lines of strip steel plant, such as pickling production line, rolling production line, finishing line, coating production line, etc., must be configured with unloading and loading coil trolley device. These devices are mainly used for the unloading and loading operation of strip steel coil and are an indispensable part of the production line. The unloading and loading coil trolley device is driven by a hydraulic system and can lift and lower the steel coil to complete the unloading and loading task. However, the traditional unloading and loading coil trolley hydraulic system has significant energy consumption problems in actual use, which limits its performance in energy saving and emission reduction.

[0003] The traditional unloading and loading coil trolley hydraulic system usually uses a double-acting hydraulic cylinder, and its working principle is relatively simple: when the steel coil needs to be lifted, the pressure oil is introduced into the piston cavity (plug cavity) of the hydraulic cylinder to push the piston rod out, thereby lifting the steel coil; at this time, the oil in the piston rod cavity (rod cavity) is discharged through the oil return pipeline. Conversely, when the steel coil needs to be lowered, the pressure oil is introduced into the piston rod cavity to push the piston rod to retract, and the oil in the piston cavity is discharged through the oil return pipeline. Although this design is intuitive and easy to implement in operation, it has obvious shortcomings in energy utilization efficiency. The weight of the steel coil is usually very large, especially under heavy load conditions, and a large amount of hydraulic energy is consumed to overcome the gravity of the steel coil during the lifting process. In the lowering process, the gravitational potential energy of the steel coil is not effectively recycled, but is wasted through the oil return to the oil tank. This one-way consumption of energy is particularly prominent in frequent lifting and lowering operations. For example, on a typical strip steel production line, the unloading and loading coil trolley may need to perform hundreds or even thousands of lifting and lowering actions every day, each operation accompanied by significant energy loss, and the long-term cumulative energy consumption cost is considerable.

[0004] In addition, the design of the traditional hydraulic system is usually based on meeting the maximum load demand, so it needs to be configured with high working pressure and flow. This not only leads to a large installed power of the hydraulic system, increasing the manufacturing and maintenance cost of the equipment, but also further exacerbates energy waste because the system still needs to maintain high pressure under no-load or light-load conditions. For example, when the system is under no-load lifting or light-load lowering, it still supplies high-pressure oil according to the standard of heavy-load lifting, but these energies are not fully used for effective work, resulting in unnecessary waste. More importantly, the gravitational potential energy released when the steel coil is lowered has great recycling potential, but the traditional system lacks corresponding energy recycling devices, so this part of energy cannot be reused.

[0005] In recent years, the industry has proposed several improvement solutions to address the high energy consumption of traditional hydraulic systems. For example, some studies have attempted to recover the potential energy of the steel coil during descent by introducing accumulators and release it during lifting to assist in the drive, thereby reducing external energy input. Other studies have adopted variable frequency drive (VFD) technology, adjusting the motor speed to match actual load requirements and reducing energy consumption during no-load operation. However, these methods still have certain limitations in practical applications. While VFD technology can optimize energy consumption to some extent, it still requires high power support during heavy-load lifting, resulting in less than ideal energy-saving effects. Furthermore, these improvement solutions often require significant modifications to existing equipment, making implementation difficult and hindering widespread adoption on existing production lines. Utility Model Content

[0006] In view of this, the purpose of this utility model is to overcome the shortcomings of the prior art and provide an energy-saving hydraulic system for loading and unloading coils.

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] An energy-saving hydraulic system for loading and unloading coils includes:

[0009] A hydraulic cylinder includes a piston rod, a cylinder body, and a plunger cover. The piston rod is slidably disposed in the cylinder body, dividing the cylinder body into a first hydraulic chamber and a second hydraulic chamber. The plunger cover is fixedly disposed at the rodless end of the cylinder body, with one end of the plunger cover passing through the second hydraulic chamber and extending into the piston rod. The piston rod and the plunger cover are slidably fitted together, and a third hydraulic chamber is formed between the plunger cover and the piston rod. The first, second, and third hydraulic chambers are physically separated from each other, and the effective area of ​​the liquid acting on the piston rod in the first hydraulic chamber is larger than the effective area of ​​the liquid acting on the piston rod in the third hydraulic chamber.

[0010] A hydraulic control system includes a high-pressure pump source, a low-pressure pump source, a hydraulic cylinder, a control valve group, a high-pressure accumulator, and a low-pressure accumulator. The high-pressure pump source and the high-pressure accumulator are connected together to a high-pressure oil circuit via pipelines to provide high-pressure hydraulic oil. The low-pressure pump source and the low-pressure accumulator are connected together to a low-pressure oil circuit via pipelines to provide low-pressure hydraulic oil.

[0011] The hydraulic cylinder is simultaneously connected to the high-pressure oil circuit, the low-pressure oil circuit, and the return oil circuit through a control valve group. The control valve group controls the switching between the first hydraulic chamber, the second hydraulic chamber, and the third hydraulic chamber and the high-pressure oil circuit, the low-pressure oil circuit, and the return oil circuit, so as to supply oil to the hydraulic cylinder or recover the contraction and falling potential energy of the hydraulic cylinder.

[0012] Furthermore, the control valve assembly includes:

[0013] A hydraulically controlled check valve assembly, comprising a first hydraulically controlled check valve, a second hydraulically controlled check valve, a third hydraulically controlled check valve, a fourth hydraulically controlled check valve, a fifth hydraulically controlled check valve, and a sixth hydraulically controlled check valve;

[0014] The proportional directional valve has four ports: A, B, P, and T. Port A is connected to the second hydraulic chamber of the hydraulic cylinder via a fifth and a sixth hydraulically controlled check valve. Port B is directly connected to the first hydraulic chamber of the hydraulic cylinder. Port P is divided into two paths: one path connects to the high-pressure oil line via a third and a first hydraulically controlled check valve, and the other path connects to the low-pressure oil line via a fourth and a second hydraulically controlled check valve, and is also connected to the low-pressure pump source via the second check valve. Port T is also divided into two paths: one path connects to the return oil line via a third hydraulically controlled check valve, and the other path connects to the low-pressure oil line via a fourth hydraulically controlled check valve.

[0015] The electromagnetic directional valve assembly includes a first electromagnetic directional valve, a second electromagnetic directional valve, and a third electromagnetic directional valve. The control terminals of the first and second hydraulically controlled check valves are controlled by the first electromagnetic directional valve to open or close with the high-pressure oil circuit or the return oil circuit. The control terminals of the third and fourth hydraulically controlled check valves are controlled by the second electromagnetic directional valve to open or close with the low-pressure oil circuit or the return oil circuit. The control terminals of the fifth and sixth hydraulically controlled check valves are controlled by the third electromagnetic directional valve to open or close with the high-pressure oil circuit.

[0016] Furthermore, the output ends of the high-pressure pump source and the low-pressure pump source are respectively equipped with a first check valve and a second check valve to prevent hydraulic oil backflow.

[0017] Furthermore, pressure sensors are installed on the high-pressure oil circuit, the low-pressure oil circuit, and the second hydraulic chamber of the hydraulic cylinder, including a first pressure sensor, a second pressure sensor, and a third pressure sensor. The first pressure sensor is located on the high-pressure oil circuit to detect the high-pressure P1; the second pressure sensor is located on the low-pressure oil circuit to detect the low-pressure P2; and the third pressure sensor is located on the pipeline of the second hydraulic chamber of the hydraulic cylinder to detect the pressure P in the second hydraulic chamber. A The loading and unloading trolley is equipped with a displacement sensor to detect the position of the hydraulic cylinder.

[0018] Furthermore, the hydraulic control system also includes a safety valve, which is located on the pipeline of the low-pressure accumulator group and is used for pressure relief.

[0019] Furthermore, there are one or more hydraulic cylinders, each hydraulic cylinder is equipped with an independent control valve group, and multiple hydraulic cylinders share or independently configure a high-pressure pump source, a low-pressure pump source, a high-pressure accumulator and a low-pressure accumulator.

[0020] Furthermore, both the high-pressure pump source and the low-pressure pump source are gear pumps driven by servo motors.

[0021] The beneficial effects of this utility model are as follows:

[0022] 1. Significantly reduce energy consumption

[0023] Traditional hydraulic systems for unloading steel coils continuously consume significant amounts of external energy during both lifting and lowering, especially during heavy-load lifting and lowering processes. This system, through innovative hydraulic cylinder design and intelligent control, enables flexible switching between high-pressure and low-pressure oil circuits under different operating conditions. Specifically:

[0024] During the lifting and rewinding process, the system automatically switches to the high-pressure oil circuit to ensure sufficient driving force;

[0025] During no-load rise and rewind descent, the system uses a low-pressure oil circuit to reduce unnecessary energy consumption.

[0026] This on-demand energy supply model effectively avoids the waste of high-pressure oil in traditional systems under light load or no-load conditions, thereby significantly reducing overall energy consumption.

[0027] 2. Reduce installed capacity and equipment costs

[0028] Traditional hydraulic systems, to meet maximum load requirements, typically require high design pressure and flow rates, resulting in high installed power and equipment costs. This invention reduces the system's design pressure and flow rate requirements by optimizing the hydraulic cylinder structure and control logic.

[0029] The special design of the hydraulic cylinder (adding a plunger cover to form three chambers) enables the system to complete some actions under low pressure, reducing the dependence on high-pressure oil sources;

[0030] The high-pressure oil circuit is only used when lifting and rewinding, while the low-pressure oil circuit is used under other operating conditions, which effectively reduces the specification requirements of the pump source and related hydraulic components.

[0031] Therefore, the total installed power of the system can be reduced, and the equipment manufacturing and maintenance costs are also reduced.

[0032] 3. Achieve energy recovery and reuse

[0033] In traditional systems, the gravitational potential energy released during the descent of the steel coil is often not effectively utilized, resulting in energy waste. This invention successfully achieves energy recovery and reuse through a low-voltage accumulator array:

[0034] During the rewinding and descent process, the oil discharged from the hydraulic cylinder is forced into the low-pressure accumulator group, converting the potential energy of the steel coil into hydraulic energy for storage.

[0035] The stored hydraulic energy can be reused in subsequent no-load rises or rewinds, reducing dependence on external energy input.

[0036] This energy recovery mechanism significantly improves the system's energy utilization efficiency, especially in production lines with frequent lifting operations, where the energy-saving effect is particularly noticeable.

[0037] 4. Reduce idle power consumption

[0038] Traditional hydraulic systems require the pump to continue running even in standby or no-load conditions, resulting in unnecessary energy consumption. This invention utilizes a gear pump driven by a servo motor, featuring adjustable speed and the ability to start and stop at any time.

[0039] When the system pressure reaches the set value, the pump source can automatically stop running, and the accumulator will provide the necessary oil supply.

[0040] The pump only starts to replenish pressure when the pressure is below the threshold, thus avoiding energy waste from long-term no-load operation.

[0041] This intelligent control strategy further improves the system's energy-saving performance, especially when multiple sets of loading and unloading trolleys share the same hydraulic oil source, the energy-saving effect is even more significant.

[0042] 5. Improve system flexibility and adaptability

[0043] Through real-time monitoring by pressure and displacement sensors, the system can automatically switch to the appropriate control mode based on the load status and position of the steel coil, ensuring efficient operation under different working conditions.

[0044] Automatically identifies heavy-load and no-load states, and flexibly switches between high-pressure and low-pressure oil circuits;

[0045] When the rewinding descent contacts the saddle, the system can switch to the no-load descent mode in a timely manner to avoid misoperation and energy waste.

[0046] This intelligent control method not only improves the system's operating efficiency, but also enhances the convenience and safety of operation.

[0047] Other advantages, objectives, and features of this invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination and study, or may be learned from practice of this invention. The objectives and other advantages of this invention can be realized and obtained through the following description. Attached Figure Description

[0048] To make the objectives, technical solutions, and advantages of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, wherein:

[0049] Fig. 1 This is a schematic diagram of the hydraulic system of the energy-saving loading and unloading trolley in this utility model.

[0050] Fig. 2 This is a schematic diagram of the structure of the hydraulic cylinder of this utility model.

[0051] Fig. 3 This is a schematic diagram of the installation of the hydraulic cylinder in this utility model.

[0052] Reference numerals: 1-Steel coil; 2-Lifting seat; 3-Traveling vehicle body; 1.1-High-pressure pump source; 2.1-Low-pressure pump source; 3.1-First check valve; 3.2-Second check valve; 3.3-Third check valve; 3.4-Fourth check valve; 4.1-First hydraulically controlled check valve; 4.2-Second hydraulically controlled check valve; 4.3-Third hydraulically controlled check valve; 4.4-Fourth hydraulically controlled check valve; 4.5-Fifth hydraulically controlled check valve; 4.6-Sixth hydraulically controlled check valve Valve; 5.1-First pressure sensor; 5.2-Second pressure sensor; 5.3-Third pressure sensor; 6.1-First solenoid directional valve; 6.2-Second solenoid directional valve; 6.3-Third solenoid directional valve; 7.1-Proportional directional valve; 8.1-High-pressure accumulator; 9.1-Low-pressure accumulator; 10.1-Safety valve; 11.1-Hydraulic cylinder; 11.11-Piston rod; 11.12-Cylinder body; 11.13-Plunger cover. Detailed Implementation

[0053] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this utility model. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0054] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the present invention. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0055] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this utility model. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0056] Please see Figs. 1-3 This is an energy-saving hydraulic system for loading and unloading coils, comprising:

[0057] Hydraulic cylinder 11.1 includes a piston rod 11.11, a cylinder body 11.12, and a plunger cover 11.13. The piston rod 11.11 is slidably disposed in the cylinder body 11.12, dividing the cylinder body 11.12 into a first hydraulic chamber and a second hydraulic chamber. The plunger cover 11.13 is fixedly disposed at the rodless end of the cylinder body 11.12, and one end of the plunger cover 11.13 passes through the second hydraulic chamber and extends into the piston rod 11.11. The piston rod 11.11 and the plunger cover 11.13 are slidably fitted together, and a third hydraulic chamber is formed between the plunger cover 11.13 and the piston rod 11.11. The first hydraulic chamber, the second hydraulic chamber, and the third hydraulic chamber are physically separated from each other, and the effective area of ​​the liquid in the first hydraulic chamber acting on the piston rod 11.11 is greater than the effective area of ​​the liquid in the third hydraulic chamber acting on the piston rod 11.11.

[0058] The hydraulic control system includes a high-pressure pump source 1.1, a low-pressure pump source 2.1, a hydraulic cylinder 11.1, a control valve group, a high-pressure accumulator 8.1, and a low-pressure accumulator 9.1. The high-pressure pump source 1.1 and the high-pressure accumulator 8.1 are connected together to the high-pressure oil circuit through pipelines to provide high-pressure hydraulic oil; the low-pressure pump source 2.1 and the low-pressure accumulator 9.1 are connected together to the low-pressure oil circuit through pipelines to provide low-pressure hydraulic oil.

[0059] The hydraulic cylinder 11.1 is simultaneously connected to the high-pressure oil circuit, the low-pressure oil circuit, and the return oil circuit through the control valve group. The control valve group controls the switching between the first hydraulic chamber, the second hydraulic chamber, the third hydraulic chamber and the high-pressure oil circuit, the low-pressure oil circuit, and the return oil circuit, so as to supply oil to the hydraulic cylinder 11.1 or recover the contraction and falling potential energy of the hydraulic cylinder 11.1.

[0060] The control valve assembly includes:

[0061] The hydraulically controlled check valve assembly includes a first hydraulically controlled check valve 4.1, a second hydraulically controlled check valve 4.2, a third hydraulically controlled check valve 4.3, a fourth hydraulically controlled check valve 4.4, a fifth hydraulically controlled check valve 4.5, and a sixth hydraulically controlled check valve 4.6.

[0062] The proportional directional valve 7.1 has four ports: A, B, P, and T. Port A of the proportional directional valve 7.1 is connected to the second hydraulic chamber of hydraulic cylinder 11.1 via the fifth hydraulic check valve 4.5 and the sixth hydraulic check valve 4.6. Port B of the proportional directional valve 7.1 is directly connected to the first hydraulic chamber of hydraulic cylinder 11.1. Port P of the proportional directional valve 7.1 is divided into two paths: one path is connected to the high-pressure oil line via the third check valve 3.3 and the first hydraulic check valve 4.1, and the other path is connected to the low-pressure oil line via the fourth check valve 3.4 and the second hydraulic check valve 4.2, and is also connected to the low-pressure pump source 2.1 via the second check valve 3.2. Port T of the proportional directional valve 7.1 is divided into two paths: one path is connected to the return oil line via the third hydraulic check valve 4.3, and the other path is connected to the low-pressure oil line via the fourth hydraulic check valve 4.4.

[0063] The electromagnetic directional valve assembly includes a first electromagnetic directional valve 6.1, a second electromagnetic directional valve 6.2, and a third electromagnetic directional valve 6.3. The control terminals of the first hydraulically controlled check valve 4.1 and the second hydraulically controlled check valve 4.2 are controlled by the first electromagnetic directional valve 6.1 to open or close the high-pressure oil circuit or the return oil circuit. The control terminals of the third hydraulically controlled check valve 4.3 and the fourth hydraulically controlled check valve 4.4 are controlled by the second electromagnetic directional valve 6.2 to open or close the low-pressure oil circuit or the return oil circuit. The control terminals of the fifth hydraulically controlled check valve 4.5 and the sixth hydraulically controlled check valve 4.6 are controlled by the third electromagnetic directional valve 6.3 to open or close the high-pressure oil circuit. The output terminals of the high-pressure pump source 1.1 and the low-pressure pump source 2.1 are respectively equipped with a first check valve 3.1 and a second check valve 3.2 to prevent hydraulic oil backflow.

[0064] Pressure sensors are installed on the high-pressure oil circuit, the low-pressure oil circuit, and the second hydraulic chamber of the hydraulic cylinder 11.1, including a first pressure sensor 5.1, a second pressure sensor 5.2, and a third pressure sensor 5.3. The first pressure sensor 5.1 is installed on the high-pressure oil circuit to detect the high-pressure P1, the second pressure sensor 5.2 is installed on the low-pressure oil circuit to detect the low-pressure P2, and the third pressure sensor 5.3 is installed on the pipeline of the second hydraulic chamber of the hydraulic cylinder 11.1 to detect the pressure PA of the second hydraulic chamber. A displacement sensor is installed on the unloading trolley to detect the position of the hydraulic cylinder 11.1.

[0065] The hydraulic control system also includes a safety valve 10.1, which is located on the pipeline of the low-pressure accumulator 9.1 and is used for pressure relief.

[0066] There are one or more hydraulic cylinders 11.1, each hydraulic cylinder 11.1 is equipped with an independent control valve group, and multiple hydraulic cylinders 11.1 share or independently configure a high-pressure pump source 1.1, a low-pressure pump source 2.1, a high-pressure accumulator 8.1 and a low-pressure accumulator 9.1. Among them, the high-pressure pump source 1.1 and the low-pressure pump source 2.1 are both gear pumps driven by servo motors.

[0067] Example 1

[0068] This embodiment describes the hydraulic system for the loading and unloading trolleys of a 1450mm leveling unit. It is applied to three trolleys (two for loading and one for unloading) to handle steel coils with a maximum weight of 28 tons. The system composition and technical solution are as follows:

[0069] 1. System Composition

[0070] Hydraulic cylinder 11.1: Each trolley is equipped with a single hydraulic cylinder 11.1, including a piston rod 11.11, a cylinder body 11.12, and a plunger cover 11.13. The piston diameter D1 is φ200mm, the piston rod 11.11 diameter D2 is φ160mm, and the plunger cover 11.13 diameter D3 is φ110mm. The cylinder body 11.12 is divided into a first hydraulic chamber (area SA = 21900mm²). 2 ), second hydraulic chamber (area SB = 11300mm) 2 ) and the third hydraulic chamber (area SA' = 9500mm) 2 ).

[0071] Hydraulic control system: including high-pressure pump source 1.1 (P1 = 16MPa, servo motor driven gear pump, equipped with first check valve 3.1), low-pressure pump source 2.1 (P2 = 6.3MPa, servo motor driven gear pump, equipped with second check valve 3.2), high-pressure accumulator 8.1, low-pressure accumulator 9.1 (equipped with safety valve 10.1, P... S =10MPa), control valve group (including first hydraulic check valve 4.1 to sixth hydraulic check valve 4.6, proportional directional valve 7.1, first solenoid directional valve 6.1 to third solenoid directional valve 6.3, third check valve 3.3, fourth check valve 3.4), first pressure sensor 5.1 (detecting P1), second pressure sensor 5.2 (detecting P2), third pressure sensor 5.3 (detecting P... A ) and displacement sensor (installed on the vehicle body 3 to detect the position of hydraulic cylinder 11.1).

[0072] 2. Working principle and usage method

[0073] Static state: Initial state, the third solenoid directional valve 6.3 is energized, the fifth hydraulic check valve 4.5 and the sixth hydraulic check valve 4.6 are closed, and the second hydraulic chamber is sealed off (P). A(Monitored by the third pressure sensor 5.3); the proportional directional valve 7.1 remains in the neutral position, the first solenoid directional valve 6.1 is energized to close the first hydraulic control check valve 4.1 and open the second hydraulic control check valve 4.2, the second solenoid directional valve 6.2 is energized to close the third hydraulic control check valve 4.3 and open the fourth hydraulic control check valve 4.4, the first hydraulic chamber and the third hydraulic chamber are connected to the low-pressure oil circuit (P2 = 6.3 MPa), and the system consumes no energy in standby mode.

[0074] Lifting and rewinding status: During winding, steel coil 1 (28 tons) is placed on lifting seat 2, and the third pressure sensor 5.3 detects P. A The pressure is raised to 13MPa (>80% of P2, i.e., 5.04MPa), and the system recognizes a heavy load. The third solenoid directional valve 6.3 is de-energized, the first solenoid directional valve 6.1 is de-energized, causing the first hydraulic control check valve 4.1 to open and the second hydraulic control check valve 4.2 to close. The second solenoid directional valve 6.2 is de-energized, causing the third hydraulic control check valve 4.3 to open and the fourth hydraulic control check valve 4.4 to close. The second hydraulic chamber is connected to the high-pressure oil circuit (P1 = 16MPa, with auxiliary oil supply from the high-pressure accumulator 8.1), the first hydraulic chamber is connected to the return oil circuit, and the third hydraulic chamber is connected to the low-pressure oil circuit. The proportional directional valve 7.1 provides an upward signal, and the hydraulic cylinder 11.1 lifts at a speed of 0.1m / s, completing a 1m stroke in 5 seconds. The steel coil 1 is then sent to the production line.

[0075] No-load rising state: No steel coil 1, P after uncoiling A When the pressure drops to 1.2 MPa (< 80% of P2), the upward movement is selected. The third solenoid directional valve 6.3 is de-energized, and the first solenoid directional valve 6.1 is energized, causing the first hydraulic check valve 4.1 to close and the second hydraulic check valve 4.2 to open. The second solenoid directional valve 6.2 is energized, causing the third hydraulic check valve 4.3 to close and the fourth hydraulic check valve 4.4 to open. All three chambers are connected to the low-pressure oil circuit (P2 = 6.3 MPa). The proportional directional valve 7.1 controls the speed at 0.15 m / s, and the valve rises 1 m to the initial position in 6.7 seconds, consuming only low-pressure energy.

[0076] Recoil Descending Status: During uncoiling, coil 1 (28 tons) descends, P A The pressure rises to 7.6 MPa (>120% of P2, i.e., 7.56 MPa). The third solenoid directional valve 6.3 is de-energized, and the first solenoid directional valve 6.1 is energized, causing the first hydraulic check valve 4.1 to close and the second hydraulic check valve 4.2 to open. The second solenoid directional valve 6.2 is energized, causing the third hydraulic check valve 4.3 to close and the fourth hydraulic check valve 4.4 to open. The three chambers are connected to the low-pressure oil circuit. The proportional directional valve 7.1 controls the descent speed to be 0.12 m / s. The oil pressure is pumped into the low-pressure accumulator 9.1, P2 rises to 9 MPa, the potential energy recovery rate is about 70%, and the descent is 1 m in 8.3 seconds.

[0077] No-load descent state: After coil 1 contacts the saddle, P AWhen the pressure drops to 1.5 MPa (< 120% of P2), the third solenoid directional valve 6.3 is de-energized, the first solenoid directional valve 6.1 is energized, causing the first hydraulic control check valve 4.1 to close and the second hydraulic control check valve 4.2 to open. The second solenoid directional valve 6.2 is de-energized, causing the third hydraulic control check valve 4.3 to open and the fourth hydraulic control check valve 4.4 to close. The second hydraulic chamber is connected to the return oil circuit, and the first and third hydraulic chambers are connected to the low-pressure oil circuit. The speed is 0.2 m / s, and the pressure drops back to its original position in 5 seconds.

[0078] 3. Energy Management

[0079] The low-pressure accumulator 9.1 recovers the rewinding potential energy. When the second pressure sensor 5.2 detects that P2 exceeds 10MPa, the safety valve 10.1 releases pressure. The high-pressure pump source 1.1 only replenishes pressure when the first pressure sensor 5.1 detects that P1 is below 16MPa, and the low-pressure pump source 2.1 replenishes pressure when P2 is below 6.3MPa. Both are maintained by the high-pressure accumulator 8.1 or the low-pressure accumulator 9.1 for daily oil supply, reducing pump source operating time.

[0080] Example 2

[0081] This embodiment describes the hydraulic system for the unloading trolley of a 2050mm steel rolling production line. A single trolley configuration can handle steel coils with a maximum weight of 35 tons. The system composition and technical solution are as follows:

[0082] 1. System Composition

[0083] Hydraulic cylinder 11.1: A single hydraulic cylinder 11.1, including piston rod 11.11, cylinder body 11.12, and plunger cover 11.13. The piston diameter D1 is φ220mm, the piston rod 11.11 diameter D2 is φ180mm, and the plunger cover 11.13 diameter D3 is φ120mm. The area of ​​the first hydraulic chamber SA = 25400mm². 2 The area of ​​the second hydraulic chamber is SB = 13600 mm². 2 The area of ​​the third hydraulic chamber is SA' = 11300 mm² 2 .

[0084] Hydraulic control system: including high-pressure pump source 1.1 (P1 = 18MPa, equipped with first check valve 3.1), low-pressure pump source 2.1 (P2 = 7MPa, equipped with second check valve 3.2), high-pressure accumulator 8.1, low-pressure accumulator 9.1 (safety valve 10.1 set P... S =11MPa), control valve group (including first hydraulic check valve 4.1 to sixth hydraulic check valve 4.6, proportional directional valve 7.1, first solenoid directional valve 6.1 to third solenoid directional valve 6.3, third check valve 3.3, fourth check valve 3.4), first pressure sensor 5.1 (detecting P1), second pressure sensor 5.2 (detecting P2), third pressure sensor 5.3 (detecting P... AThe pumps are equipped with a displacement sensor (mounted on the vehicle body 3) and a servo motor-driven gear pump.

[0085] 2. Working principle and usage method

[0086] In static state: Initial standby, the third solenoid directional valve 6.3 is energized, the fifth pilot-operated check valve 4.5 and the sixth pilot-operated check valve 4.6 are closed, and the second hydraulic chamber is sealed off; the proportional directional valve 7.1 is in the neutral position, the first solenoid directional valve 6.1 is energized to close the first pilot-operated check valve 4.1 and open the second pilot-operated check valve 4.2, the second solenoid directional valve 6.2 is energized to close the third pilot-operated check valve 4.3 and open the fourth pilot-operated check valve 4.4, the first hydraulic chamber and the third hydraulic chamber are connected to the low-pressure oil circuit (P2 = 7MPa), and the system consumes no energy.

[0087] Lifting and rewinding status: During winding, steel coil 1 (35 tons) is placed on lifting platform 2, P A The pressure is raised to 15MPa (>80% of P2, i.e., 5.6MPa). The third solenoid directional valve 6.3 is de-energized, and the first solenoid directional valve 6.1 is de-energized, causing the first hydraulic check valve 4.1 to open and the second hydraulic check valve 4.2 to close. The second solenoid directional valve 6.2 is de-energized, causing the third hydraulic check valve 4.3 to open and the fourth hydraulic check valve 4.4 to close. The second hydraulic chamber is connected to the high-pressure oil circuit (P1 = 18MPa, supplied by the high-pressure accumulator 8.1), the first hydraulic chamber is connected to the return oil circuit, and the third hydraulic chamber is connected to the low-pressure oil circuit. The proportional directional valve 7.1 controls the speed to 0.08m / s, raising the pressure by 0.5m to the production line height in 6.25 seconds.

[0088] No-load rising state: No steel coil 1, P after uncoiling A At 1.8 MPa (< 80% of P2), the upward movement is selected. The third solenoid directional valve 6.3 is de-energized, the first solenoid directional valve 6.1 is energized, causing the first hydraulic control check valve 4.1 to close and the second hydraulic control check valve 4.2 to open. The second solenoid directional valve 6.2 is energized, causing the third hydraulic control check valve 4.3 to close and the fourth hydraulic control check valve 4.4 to open. The three chambers are connected to the low-pressure oil circuit (P2 = 7 MPa), the speed is 0.2 m / s, and the rise is 0.5 m in 2.5 seconds, using only low-pressure oil.

[0089] Recoil descent state: During uncoiling, coil 1 (35 tons) descends, P AThe pressure reaches 8.5 MPa (>120% of P2, i.e., 8.4 MPa). The third solenoid directional valve 6.3 is de-energized, the first solenoid directional valve 6.1 is energized, causing the first hydraulic control check valve 4.1 to close and the second hydraulic control check valve 4.2 to open. The second solenoid directional valve 6.2 is energized, causing the third hydraulic control check valve 4.3 to close and the fourth hydraulic control check valve 4.4 to open. The three chambers are connected to the low-pressure oil circuit. The proportional directional valve 7.1 controls the speed to 0.1 m / s. The oil pressure is pumped into the low-pressure accumulator 9.1, P2 rises to 10.5 MPa, the potential energy recovery rate is about 65%, and it drops by 0.5 m in 5 seconds.

[0090] No-load descent state: Coil 1 contacts the saddle, P A When the pressure drops to 2 MPa (< 120% of P2), the third solenoid directional valve 6.3 is de-energized, the first solenoid directional valve 6.1 is energized, causing the first hydraulic control check valve 4.1 to close and the second hydraulic control check valve 4.2 to open. The second solenoid directional valve 6.2 is de-energized, causing the third hydraulic control check valve 4.3 to open and the fourth hydraulic control check valve 4.4 to close. The second hydraulic chamber is connected to the return oil circuit, and the first and third hydraulic chambers are connected to the low-pressure oil circuit. The speed is 0.15 m / s, and the pressure drops back to its original position in 3.3 seconds.

[0091] 3. Energy Management

[0092] The rewinding potential energy is stored in the low-pressure accumulator 9.1. When P2 exceeds 11MPa, the safety valve 10.1 releases pressure. The high-pressure pump source 1.1 replenishes pressure when P1 is below 18MPa, and the low-pressure pump source 2.1 replenishes pressure when P2 is below 7MPa. The accumulator maintains oil supply, reducing energy consumption.

[0093] The above embodiments demonstrate that this utility model, through innovative hydraulic cylinder 11.1 design and intelligent control, achieves high efficiency and energy saving under different loads and working conditions, and is applicable to various strip steel production lines.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of this technical solution, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. An energy-saving type of hydraulic system for an on-off coil car, characterized in that, The hydraulic cylinder comprises a piston rod, a cylinder body, and a plunger cover, the piston rod is slidably arranged in the cylinder body, and the cylinder body is divided into a first hydraulic cavity and a second hydraulic cavity; the plunger cover is fixedly arranged at a rodless cavity end of the cylinder body, one end of the plunger cover penetrates through the second hydraulic cavity and extends into the piston rod; the piston rod and the plunger cover are in sliding fit, and a third hydraulic cavity is formed between the plunger cover and the piston rod; the first hydraulic cavity, the second hydraulic cavity, and the third hydraulic cavity are physically separated from each other, and the effective area of the liquid in the first hydraulic cavity acting on the piston rod is greater than the effective area of the liquid in the third hydraulic cavity acting on the piston rod; The hydraulic control system comprises a high-pressure pump source, a low-pressure pump source, a hydraulic cylinder, a control valve group, a high-pressure accumulator, and a low-pressure accumulator; the high-pressure pump source and the high-pressure accumulator are connected to a high-pressure oil circuit through a pipeline, and are used for providing high-pressure hydraulic oil; the low-pressure pump source and the low-pressure accumulator are connected to a low-pressure oil circuit through a pipeline, and are used for providing low-pressure hydraulic oil; The hydraulic cylinder is connected to the high-pressure oil circuit, the low-pressure oil circuit, and an oil return circuit through the control valve group, and the switching between the first hydraulic cavity, the second hydraulic cavity, and the third hydraulic cavity and the high-pressure oil circuit, the low-pressure oil circuit, and the oil return circuit is controlled through the control valve group, so that the hydraulic cylinder is supplied with oil or the contraction potential energy of the hydraulic cylinder is recovered. The control valve group comprises:

2. The energy-saving hydraulic system for the on- and off-roll car according to claim 1, characterized in that, a hydraulic control check valve group, the hydraulic control check valve group comprises a first hydraulic control check valve, a second hydraulic control check valve, a third hydraulic control check valve, a fourth hydraulic control check valve, a fifth hydraulic control check valve, and a sixth hydraulic control check valve; a proportional directional valve, the proportional directional valve is provided with A, B, P, and T four interfaces, wherein the A interface of the proportional directional valve is connected to the second hydraulic cavity of the hydraulic cylinder through the fifth hydraulic control check valve and the sixth hydraulic control check valve in sequence; the B interface of the proportional directional valve is directly connected to the first hydraulic cavity of the hydraulic cylinder; the P interface of the proportional directional valve is divided into two paths, one path is connected to the high-pressure oil circuit through the third check valve and the first hydraulic control check valve in sequence, and the other path is connected to the low-pressure oil circuit through the fourth check valve and the second hydraulic control check valve in sequence, and is connected to the low-pressure pump source through the second check valve; the T interface of the proportional directional valve is divided into two paths, one path is connected to the oil return circuit through the third hydraulic control check valve, and the other path is connected to the low-pressure oil circuit through the fourth hydraulic control check valve; an electromagnetic directional valve group, the electromagnetic directional valve group comprises a first electromagnetic directional valve, a second electromagnetic directional valve, and a third electromagnetic directional valve, wherein the control ends of the first hydraulic control check valve and the second hydraulic control check valve are controlled to realize the switching between the high-pressure oil circuit or the oil return circuit through the first electromagnetic directional valve; the control ends of the third hydraulic control check valve and the fourth hydraulic control check valve are controlled to realize the switching between the low-pressure oil circuit or the oil return circuit through the second electromagnetic directional valve; the control ends of the fifth hydraulic control check valve and the sixth hydraulic control check valve are controlled to realize the switching between the high-pressure oil circuit through the third electromagnetic directional valve. The output ends of the high-pressure pump source and the low-pressure pump source are respectively provided with first and second check valves, which are used for preventing the backflow of hydraulic oil.

3. The energy-saving hydraulic system for the on- and off-roll car according to claim 1, characterized in that: The hydraulic control system further comprises a safety valve, which is arranged on the pipeline of the low-pressure accumulator group and is used for pressure relief.

4. The energy-saving hydraulic system for the on- and off-roll car according to claim 1, characterized in that: The high-pressure oil way, the low-pressure oil way and the second hydraulic cavity of the hydraulic cylinder are all provided with pressure sensors, including a first pressure sensor, a second pressure sensor and a third pressure sensor, wherein the first pressure sensor is arranged on the high-pressure oil way and is used for detecting high-pressure P1, the second pressure sensor is arranged on the low-pressure oil way and is used for detecting low-pressure P2, and the third pressure sensor is arranged on the pipeline of the second hydraulic cavity of the hydraulic cylinder and is used for detecting the second hydraulic cavity pressure P A A displacement sensor is arranged on the upper unloading cart and is used for detecting the position of the hydraulic cylinder.

5. The energy-saving hydraulic system for the on- and off-roll car according to claim 1, characterized in that: ​ 6. The energy-saving hydraulic system for the on- and off-roll car according to claim 1, characterized in that: The hydraulic cylinders are one or more, each of which is respectively provided with an independent control valve group, and the multiple hydraulic cylinders share or independently configure a high-pressure pump source, a low-pressure pump source, a high-pressure accumulator and a low-pressure accumulator.

7. The energy-saving hydraulic system for the on- and off-roll car according to claim 1, characterized in that: The high-pressure pump source and the low-pressure pump source are both gear pumps driven by servo motors.

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