Novel energy-saving servo hydraulic control system and hydraulic grab thereof

Abstract

This utility model discloses a novel energy-saving servo hydraulic control system for controlling the extension and retraction of at least one hydraulic cylinder. It includes a control valve, an oil pump driven by a servo motor, and an oil tank. The oil pump is connected to the oil tank. The control valve includes an oil outlet line, an overflow line, and a return line. The oil outlet line is connected to the oil pump and is connected to the rodless chamber of the hydraulic cylinder via a first line and to the rod chamber via a second line. A solenoid valve and a check valve are sequentially installed on both the first and second lines. The hydraulic sensor in this utility model converts pressure signals into electrical signals in real time and feeds them back to the controller. The controller performs program calculations and adjusts the servo motor speed in real time. When the pressure value reaches the program-set maximum value, the controller stops the servo motor. At this time, the hydraulic system consumes no energy, preventing overheating of the hydraulic system.

Description

Technical Field

[0001] This utility model relates to the technical field of grabs, and in particular to a novel energy-saving servo hydraulic control system and its hydraulic grab. Background Technology

[0002] In the field of modern industrial automation, mechanical grabs are key equipment widely used in material handling and loading / unloading. Their stability and reliability are crucial for improving production efficiency and reducing labor intensity. With the continuous advancement of servo control technology, servo hydraulic systems, due to their high precision and high response speed, have gradually become the mainstream choice for mechanical grab drive systems. However, in practical applications, especially when mechanical grabs perform complex grabbing tasks (such as grabbing materials of uneven weight or irregular shape, or operating under harsh conditions), servo hydraulic systems face a series of challenges. The most prominent problem is the servo motor's susceptibility to overload.

[0003] When a mechanical grab encounters a load exceeding its design capacity during operation, or when the grabbing resistance increases abnormally due to material characteristics (such as adhesion or poor flowability), the servo motor needs to output greater torque to maintain the grab's normal operation. This instantaneous high load demand often exceeds the servo motor's rated output capacity, leading to overload. Under overload conditions, the internal current of the servo motor increases sharply, causing the motor winding temperature to rise rapidly. This not only accelerates the aging of the motor's insulation materials and shortens the motor's lifespan, but may also trigger the motor's overheat protection mechanism, forcing the system to shut down and affecting production continuity. Furthermore, servo motor overload not only directly causes the motor itself to heat up, but also affects the thermal environment of the entire servo hydraulic system through heat conduction and radiation, exacerbating the temperature rise of the hydraulic oil, reducing its viscosity and lubrication performance, and further deteriorating the system's operating conditions, creating a vicious cycle. The high-temperature environment not only reduces the working efficiency of hydraulic components and increases energy consumption, but may also cause oxidation and deterioration of the hydraulic oil, producing corrosive substances that damage the system's internal structure. Utility Model Content

[0004] In view of the above-mentioned problems of existing servo hydraulic systems, this paper aims to provide a new type of energy-saving servo hydraulic control system and its hydraulic grab bucket.

[0005] The specific technical solution is as follows:

[0006] A novel energy-saving servo hydraulic control system for controlling the extension and retraction of at least one hydraulic cylinder includes: a control valve, an oil pump driven by a servo motor, and an oil tank. The oil pump is connected to the oil tank, and the control valve includes:

[0007] The oil outlet line is connected to the oil pump. The oil outlet line is connected to the rodless chamber of the hydraulic cylinder through a first line and to the rod chamber of the hydraulic cylinder through a second line. A solenoid valve and a check valve are sequentially installed on both the first line and the second line.

[0008] An overflow pipeline is provided, which is connected between the oil outlet pipeline and the oil tank, and an overflow valve is provided on the overflow pipeline.

[0009] The main return oil pipeline has one end connected to the oil tank, and the other end connected to the first pipeline via a first return oil branch pipeline and to the second pipeline via a second return oil branch pipeline. A balancing valve is provided on both the first main return oil pipeline and the second return oil branch pipeline.

[0010] As a further improvement and optimization of this solution, the first return oil branch line / second return oil branch line is located downstream of the one-way valve.

[0011] As a further improvement and optimization of this solution, hydraulic testing devices are provided on the first pipeline, the second pipeline, and the oil outlet pipeline.

[0012] As a further improvement and optimization of this solution, the hydraulic testing device is a hydraulic sensor.

[0013] As a further improvement and optimization of this solution, the oil pump and the oil tank are connected by an oil pipe.

[0014] A novel energy-saving hydraulic grab bucket includes any one of the above-mentioned servo hydraulic control systems, and further includes:

[0015] Frame;

[0016] A plurality of claw-like segments, one end of which is respectively hinged to the frame;

[0017] A plurality of hydraulic cylinders, one end of which is hinged to the frame and the other end of which is hinged to the outer side of the plurality of claws respectively, and the servo hydraulic control system is connected to the plurality of hydraulic cylinders for driving the plurality of hydraulic cylinders to synchronously extend and retract, so that the plurality of claws close or open.

[0018] As a further improvement and optimization of this solution, the rodless chambers of several hydraulic cylinders are respectively connected to the first pipeline through a first branch, and the rod chambers are respectively connected to the second pipeline through a second branch.

[0019] As a further improvement and optimization of this solution, a cylinder is formed on the frame, and the servo hydraulic control system is located inside the cylinder.

[0020] As a further improvement and optimization of this solution, one end of several claw petals is hinged to the bottom side of the frame, and several claw petals are arranged at equal intervals along the circumference of the frame.

[0021] As a further improvement and optimization of this solution, one end of each of the hydraulic cylinders is hinged to the top side of the frame.

[0022] The positive effects of the above technical solution compared with the existing technology are:

[0023] The maximum output pressure of this invention is determined by the control program in the controller. The hydraulic sensor converts the pressure signal into an electrical signal in real time and feeds it back to the controller. The controller performs program calculations and adjusts the servo motor speed in real time. When the pressure value reaches the maximum value set by the program, the controller will stop the servo motor from working. At this time, the hydraulic system consumes no energy and prevents the hydraulic system from overheating.

[0024] In this utility model hydraulic system, by setting up an overflow pipeline and an overflow valve, the maximum pressure of the hydraulic system is protected from exceeding the rated value in case of improper debugging or failure of other pressure valves. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the oil circuit of a novel energy-saving servo hydraulic control system according to this utility model;

[0026] Figure 2 This is a schematic diagram of the structure of a novel energy-saving hydraulic grab bucket according to this utility model;

[0027] In the attached diagram: 1. Hydraulic cylinder; 2. Oil tank; 3. Servo motor; 4. Oil pump; 5. Control valve; 6. Frame; 7. Claw valve; 21. Main return oil line; 22. Overflow line; 50. Second return oil branch line; 51. Solenoid valve; 52. Balance valve; 53. Check valve; 54. Overflow valve; 56. Oil outlet line; 57. First line; 58. Second line; 59. First return oil branch line. Detailed Implementation

[0028] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0029] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used 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, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0031] Figure 1 This is a schematic diagram of the oil circuit of a novel energy-saving servo hydraulic control system according to this utility model. Figure 2 This is a schematic diagram of the structure of a novel energy-saving hydraulic grab bucket according to this utility model. Figure 1-2 The diagram illustrates a novel energy-saving servo hydraulic control system according to a preferred embodiment, used to control the extension and retraction of at least one hydraulic cylinder 1. The system includes: a control valve 5, an oil pump 4 driven by a servo motor 3, and an oil tank 2. The oil pump 4 is connected to the oil tank 2. The control valve 5 includes: an oil outlet line 56, an overflow line 22, and a return line 21. The oil outlet line 56 is connected to the oil pump 4, and is connected to the rodless chamber of the hydraulic cylinder 4 via a first line 57 and to the rod chamber of the hydraulic cylinder 4 via a second line 58. The first pipeline 57 and the second pipeline 58 are each equipped with a solenoid valve 51 and a check valve 53 in sequence. The overflow pipeline 22 is connected between the oil outlet pipeline 56 and the oil tank 2, and an overflow valve 54 is installed on the overflow pipeline 22. One end of the return oil main pipeline 21 is connected to the oil tank 2, and the other end of the return oil main pipeline 21 is connected to the first pipeline 57 through the first return oil branch pipeline and to the second pipeline 58 through the second return oil branch pipeline. A balance valve 52 is installed on both the first return oil main pipeline 21 and the second return oil branch pipeline.

[0032] Furthermore, as a preferred embodiment, the first return oil branch line / second return oil branch line is located downstream of the one-way valve 53.

[0033] Furthermore, as a preferred embodiment, hydraulic testing devices are provided on the first pipeline 57, the second pipeline 58, and the oil outlet pipeline 56.

[0034] Furthermore, as a preferred embodiment, the hydraulic testing device is a hydraulic sensor.

[0035] Furthermore, as a preferred embodiment, the oil pump 4 is connected to the oil tank 2 via an oil pipe.

[0036] A novel energy-saving hydraulic grab includes any of the aforementioned servo hydraulic control systems, as well as a frame 6, several claw flaps 7, and several hydraulic cylinders 1. One end of each claw flap 7 is hinged to the frame 6, and one end of each hydraulic cylinder 1 is hinged to the frame 6 and the other end is hinged to the outer side of each claw flap 7. The servo hydraulic control system is connected to the hydraulic cylinders 1 to drive the hydraulic cylinders 1 to move synchronously to extend and retract, so that the claw flaps 7 close or open.

[0037] Furthermore, as a preferred embodiment, the rodless chambers of several hydraulic cylinders 1 are respectively connected to the first pipeline 57 via a first branch, and the rod chambers are respectively connected to the second pipeline 58 via a second branch.

[0038] Furthermore, as a preferred embodiment, a cylinder is formed on the frame 6, and the servo hydraulic control system is located inside the cylinder.

[0039] Furthermore, as a preferred embodiment, one end of several claw petals 7 is hinged to the bottom side of the frame 6, and the several claw petals 7 are evenly spaced along the circumference of the frame 6.

[0040] Furthermore, as a preferred embodiment, one end of several hydraulic cylinders 1 is respectively hinged to the top side of the frame 6.

[0041] The specific working principle of a hydraulic grab bucket is as follows:

[0042] When the power is turned on, the servo motor 3 rotates, and the oil pump 4 supplies oil to the control valve 5 through the oil outlet pipe 56. Since the two solenoid valves 51 are not energized and are closed, the controller does not receive the energization signal of the two solenoid valves 51 and executes the servo motor 3 stop movement program. There is no hydraulic oil flow in the system, so the hydraulic cylinder 1 is locked and does not move, so the grab is in a safe stop state. At this time, the grab is in the work preparation or safe stop state, and the hydraulic system has no energy consumption.

[0043] When the grab bucket is closed, the solenoid valve 51 on the first pipeline 57 is energized and opened, and the controller receives the energizing signal of the battery valve and executes the start of the servo motor 3 so that the hydraulic oil can pass through the first pipeline 57 to the rodless chamber of the hydraulic cylinder 4.

[0044] As the oil pump 4 continuously inputs hydraulic oil, the pressure in the oil outlet line 56 increases. After the rodless chamber of the hydraulic cylinder 1 receives oil, the piston rod extends outward. Since the solenoid valve 51 on the first line 57 controls the balance valve 52 on the second return line 50, when the pressure in the oil outlet line 56 increases, the balance valve 52 on the second return line 50 opens, allowing the hydraulic oil in the rod chamber of the hydraulic cylinder 1 to flow back to the oil tank 2 through the second line 58 and the second return line 50. Therefore, the extension of the piston rod of the hydraulic cylinder 1 drives the claw flap 7 to close.

[0045] When the grab bucket is opened, the solenoid valve 51 on the second pipeline 58 is energized and opened. The controller receives the energizing signal from the solenoid valve 51 on the second pipeline 58 and executes the motor start. After the rod chamber of the hydraulic cylinder 1 receives the hydraulic oil source, it retracts. The solenoid valve 51 on the second pipeline 58 controls the balance valve 52 on the first return oil branch 59. When the pressure in the oil outlet pipeline 56 increases, the balance valve 52 on the first return oil branch 59 opens, so that the hydraulic oil in the rodless chamber of the hydraulic cylinder 1 flows back to the oil tank 2 through the first pipeline 57 and the first return oil branch 59.

[0046] Preferably, the balance valve, solenoid valve, and relief valve are all electric valves and are electrically connected to the controller, and the hydraulic sensor is also electrically connected to the controller.

[0047] Preferably, the controller can be a programmable logic controller (PLC) with closed-loop control function.

[0048] In this embodiment, the maximum output pressure is determined by the control program in the controller. The hydraulic sensor converts the pressure signal into an electrical signal in real time and feeds it back to the controller. The controller performs program calculations and adjusts the speed of the servo motor 3 in real time. When the pressure value reaches the maximum value set by the program, the controller will stop the servo motor 3 from working. At this time, the hydraulic system consumes no energy and prevents the hydraulic system from overheating.

[0049] In this embodiment, the hydraulic system is equipped with an overflow pipe 22 and an overflow valve 54 to protect the maximum pressure of the hydraulic system from exceeding the rated value in case of improper debugging or failure of other pressure valves.

[0050] The above description is only a preferred embodiment of the present utility model and does not limit the implementation method and protection scope of the present utility model. Those skilled in the art should realize that all solutions obtained by equivalent substitutions and obvious changes made based on the description and illustrations of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A novel energy-saving servo hydraulic control system for controlling the extension and retraction of at least one hydraulic cylinder, characterized in that, include: The control valve comprises a control valve, an oil pump driven by a servo motor, and an oil tank, wherein the oil pump is connected to the oil tank, and the control valve includes: The oil outlet line is connected to the oil pump. The oil outlet line is connected to the rodless chamber of the hydraulic oil pump through a first line and to the rod chamber of the hydraulic oil pump through a second line. A solenoid valve and a check valve are sequentially installed on both the first line and the second line. An overflow pipeline is provided, which is connected between the oil outlet pipeline and the oil tank, and an overflow valve is provided on the overflow pipeline. The main return oil pipeline has one end connected to the oil tank, and the other end connected to the first pipeline via a first return oil branch pipeline and to the second pipeline via a second return oil branch pipeline. A balancing valve is provided on both the first main return oil pipeline and the second return oil branch pipeline.

2. The novel energy-saving servo hydraulic control system according to claim 1, characterized in that, The first return oil branch line / second return oil branch line is located downstream of the one-way valve.

3. The novel energy-saving servo hydraulic control system according to claim 1, characterized in that, Hydraulic testing devices are installed on the first pipeline, the second pipeline, and the oil outlet pipeline.

4. The novel energy-saving servo hydraulic control system according to claim 3, characterized in that, The hydraulic testing device is a hydraulic sensor.

5. The novel energy-saving servo hydraulic control system according to claim 1, characterized in that, The oil pump is connected to the oil tank via an oil pipe.

6. A novel energy-saving hydraulic grab bucket, characterized in that, The servo hydraulic control system according to any one of claims 1-5 further includes: Frame; A plurality of claw-like segments, one end of which is respectively hinged to the frame; A plurality of hydraulic cylinders, one end of which is hinged to the frame and the other end of which is hinged to the outer side of the plurality of claws respectively, and the servo hydraulic control system is connected to the plurality of hydraulic cylinders for driving the plurality of hydraulic cylinders to synchronously extend and retract, so that the plurality of claws close or open.

7. The novel energy-saving hydraulic grab bucket according to claim 6, characterized in that, The rodless chambers of several hydraulic cylinders are respectively connected to the first pipeline via a first branch, and the rod chambers are respectively connected to the second pipeline via a second branch.

8. The novel energy-saving hydraulic grab bucket according to claim 6, characterized in that, A cylindrical body is formed on the frame, and the servo hydraulic control system is located inside the cylindrical body.

9. The novel energy-saving hydraulic grab bucket according to claim 6, characterized in that, One end of each of the claw petals is hinged to the bottom side of the frame, and the claw petals are evenly spaced along the circumference of the frame.

10. The novel energy-saving hydraulic grab bucket according to claim 9, characterized in that, One end of each of the hydraulic cylinders is hinged to the top side of the frame.

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