A hydraulic redundant servo control device

Abstract

This utility model discloses a hydraulic redundant servo control device, including an outer cylinder, an inner cylinder coaxially slidably connected inside the outer cylinder, and a piston component disposed in the inner cylinder. One end of the piston component is rigidly connected to the load connection end, and the other end is slidably connected inside the inner cylinder. This utility model, through a nested double cylinder design, reduces the space occupied compared to the traditional parallel cylinder scheme while ensuring redundancy and fault tolerance. The independent motion control of the outer and inner cylinders allows the other cylinder to still drive the load through the piston component when one cylinder is stuck, completely solving the problem of chain failure due to jamming of parallel cylinders. The guide and sealing components and the sealing ring achieve multi-stage dynamic sealing to ensure zero cross-flow of hydraulic oil between the two chambers. The A and B ports of the first and second electro-hydraulic servo valves are strictly connected to the rodless chamber and the rod chamber respectively, ensuring that the bidirectional motion capability is not lost after a single-channel failure. The independent hydraulic source design eliminates risks from the source.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic servo control technology, and in particular to a hydraulic redundant servo control device. Background Technology

[0002] Hydraulic servo systems are widely used due to their advantages such as high power density, fast response, and high control precision. However, traditional single-channel hydraulic servo systems have the risk of single-point failure. Once critical components such as cylinders, servo valves, or hydraulic power sources fail, the entire system will fail, potentially leading to serious consequences. To improve reliability, existing technologies mainly adopt the following redundancy methods:

[0003] Parallel cylinder redundancy: Two or more independent cylinders are connected in parallel to drive the same load. Disadvantages: Large space occupation, complex structure, load connection stiffness may be affected, and jamming of a single cylinder may lead to cascading failure.

[0004] Electronic / control redundancy: Uses multiple sensors, controllers, or servo valves, but ultimately acts on the same actuator cylinder; Disadvantage: Cannot solve problems such as cylinder jamming, internal leakage, or oil source failure.

[0005] Dual-valve-controlled single cylinder: Two servo valves are connected in parallel to control one cylinder. Disadvantage: It cannot solve cylinder body failures and oil source failures.

[0006] Therefore, it is necessary to design a hydraulic redundant servo control device. Utility Model Content

[0007] The purpose of this invention is to provide a hydraulic redundant servo control device to solve the problems of existing parallel cylinder redundancy, such as large space occupation, complex structure, possible impact on load connection stiffness, and the possibility of a single cylinder jamming hindering load movement. Electronic / control redundancy and dual-valve controlled single cylinder cannot solve the problems of cylinder body failure and oil source failure.

[0008] To solve the above-mentioned technical problems, this utility model provides the following technical solution: a hydraulic redundant servo control device, including an outer oil cylinder, an inner oil cylinder coaxially slidably connected inside the outer oil cylinder, and a piston component disposed in the inner oil cylinder. One end of the piston component is rigidly connected to the load connection end, and the other end is slidably connected inside the inner oil cylinder. By moving the piston component in the inner oil cylinder and moving the inner oil cylinder in the outer oil cylinder, the piston component can be dually controlled.

[0009] An outer oil cavity is formed between the outer oil cylinder and the inner oil cylinder, and an inner oil cavity is formed inside the inner oil cylinder. The inner oil cavity and the outer oil cavity are isolated from each other.

[0010] The outer oil chamber is connected to the first independent hydraulic servo unit through the first oil circuit. The first independent hydraulic servo unit includes a first hydraulic source and a first electro-hydraulic servo valve connected to the first hydraulic source. The A port and B port of the first electro-hydraulic servo valve are respectively connected to the rodless chamber and the rod chamber of the outer oil chamber through the first oil circuit. Oil is supplied to the outer oil chamber through the first electro-hydraulic servo valve to control the movement of the inner oil cylinder in the outer oil chamber.

[0011] The inner oil chamber is connected to the second independent hydraulic servo unit through the second oil circuit. The second independent hydraulic servo unit includes a second hydraulic source and a second electro-hydraulic servo valve connected to the second hydraulic source. The A port and B port of the second electro-hydraulic servo valve are respectively connected to the rodless chamber and the rod chamber of the inner oil chamber through the second oil circuit. Oil is supplied to the inner oil chamber through the second electro-hydraulic servo valve to control the piston to move in the inner oil chamber.

[0012] The second independent hydraulic servo unit controls the piston to move in the inner cylinder, and the first independent hydraulic servo unit controls the inner cylinder to move in the outer cylinder.

[0013] As a further technical solution of this utility model, it also includes a guiding and sealing assembly, which includes a guide ring disposed between the inner wall of the outer cylinder and the inner wall of the inner cylinder, and a sealing ring disposed on the inner cylinder and the piston. The guide ring and the sealing ring are used to ensure the movement stability of the inner cylinder and the piston and the hydraulic oil sealing performance.

[0014] As a further technical solution of this utility model, it also includes a sensor group, which includes a displacement sensor disposed on the outer oil cylinder and the inner oil cylinder, a pressure sensor disposed on the first oil circuit and the second oil circuit, and a valve core sensor for monitoring the valve core position of the first electro-hydraulic servo valve and the second electro-hydraulic servo valve. The displacement sensor is used to measure the displacement of the piston relative to the outer oil cylinder and the inner oil cylinder, the pressure sensor is used to monitor the pressure of each chamber, and the valve core sensor is used to provide feedback on the actual position of the valve core.

[0015] As a further technical solution of this utility model, it also includes a fault detection and switching module. The signal input terminal of the fault detection and switching module is connected to the sensor group, and the signal output terminal is connected to the control terminal of the first electro-hydraulic servo valve and the second electro-hydraulic servo valve. The fault detection and switching module is used to receive all sensor data in real time, and comprehensively judge whether the system is faulty by comparing the command position with the actual displacement, monitoring abnormal pressure, checking the deviation between valve command and valve feedback, and checking for no response after timeout. When a fault occurs, the system control is switched.

[0016] As a further technical solution of this utility model, the axial coverage length of the guide ring meets the stroke requirements of the inner cylinder and piston, ensuring the motion stability of the inner cylinder and piston.

[0017] As a further technical solution of this utility model, the first hydraulic source and the second hydraulic source are physically isolated independent hydraulic pump stations, or hydraulic branch circuits with independent accumulators and isolation valves drawn from the same power source.

[0018] As a further technical solution of this utility model, both the outer cylinder and the inner cylinder are provided with sealing rings between themselves and the piston to ensure the sealing of the hydraulic oil.

[0019] The hydraulic redundant servo control device provided by this utility model has the following advantages:

[0020] Through a nested dual-cylinder design, the outer cylinder encloses the inner cylinder, and the inner cylinder encloses the piston. Combined with physically isolated first and second independent hydraulic servo units, this design reduces space requirements compared to traditional parallel cylinder solutions while ensuring redundancy and fault tolerance. The independent motion control of the outer and inner cylinders allows the other cylinder to continue driving the load through the piston even if one cylinder jams, completely solving the problem of chain failure due to jamming in parallel cylinders. The guide and sealing components and sealing rings achieve multi-stage dynamic sealing, ensuring zero cross-contamination of hydraulic oil between the two chambers.

[0021] The A and B ports of the first and second electro-hydraulic servo valves are strictly connected to the rodless and rod-side chambers respectively, ensuring that bidirectional motion capability is not lost after a single-channel failure; the fault detection and switching module makes real-time decisions based on multi-source data of displacement, pressure and valve core position, achieving rapid and seamless switching; the independent hydraulic source design eliminates risks from the source, and the system can still maintain good output performance in the event of a single-point failure. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0024] In the diagram: 1. Outer cylinder; 2. Inner cylinder; 3. Piston; 4. Load connection end; 5. Outer oil chamber; 6. Inner oil chamber; 7. First hydraulic source; 8. First electro-hydraulic servo valve; 9. First oil circuit; 10. Second hydraulic source; 11. Second electro-hydraulic servo valve; 12. Second oil circuit; 13. Guide and sealing assembly; 131. Guide ring; 132. Sealing ring; 14. Fault detection and switching module; 15. Sensor group; 151. Displacement sensor; 152. Pressure sensor; 153. Valve core sensor; 16. Sealing ring. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0026] 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.

[0027] Please see the appendix Figure 1 The present invention provides an embodiment of a hydraulic redundant servo control device, comprising an outer cylinder 1, an inner cylinder 2 coaxially slidably connected inside the outer cylinder 1, and a piston 3 disposed in the inner cylinder 2. A sealing ring 16 is provided between the outer cylinder 1 and the inner cylinder 2 and the piston 3 to ensure the sealing of the hydraulic oil. One end of the piston 3 is rigidly connected to the load connection end 4, and the other end is slidably connected inside the inner cylinder 2. By moving the piston 3 in the inner cylinder 2 and moving the inner cylinder 2 in the outer cylinder 1, the piston 3 can be dually controlled.

[0028] An outer oil chamber 5 is formed between the outer oil cylinder 1 and the inner oil cylinder 2, and an inner oil chamber 6 is formed inside the inner oil cylinder 2. The inner oil chamber 6 and the outer oil chamber 5 are isolated from each other.

[0029] The outer oil chamber 5 is connected to the first independent hydraulic servo unit through the first oil passage 9. The first independent hydraulic servo unit includes a first hydraulic source 7 and a first electro-hydraulic servo valve 8 connected to the first hydraulic source 7. The A port and B port of the first electro-hydraulic servo valve 8 are respectively connected to the rodless chamber and the rod chamber of the outer oil chamber 5 through the first oil passage 9. Oil is supplied to the outer oil chamber 5 through the first electro-hydraulic servo valve 8 to control the movement of the inner oil cylinder 2 in the outer oil chamber 5.

[0030] The inner oil chamber 6 is connected to the second independent hydraulic servo unit through the second oil circuit 12. The second independent hydraulic servo unit includes a second hydraulic source 10 and a second electro-hydraulic servo valve 11 connected to the second hydraulic source 10. The A port and B port of the second electro-hydraulic servo valve 11 are respectively connected to the rodless chamber and the rod chamber of the inner oil chamber 6 through the second oil circuit 12. Oil is supplied to the inner oil chamber 6 through the second electro-hydraulic servo valve 11 to control the piston 3 to move in the inner oil chamber 6. The first hydraulic source 7 and the second hydraulic source 10 are physically isolated independent hydraulic pump stations, or hydraulic branch circuits with independent accumulators and isolation valves drawn from the same power source.

[0031] The second independent hydraulic servo unit controls the piston 3 to move in the inner cylinder 2, and the first independent hydraulic servo unit controls the inner cylinder 2 to move in the outer cylinder 1.

[0032] It also includes a guide and sealing assembly 13, a fault detection and switching module 14, and a sensor group 15. The guide and sealing assembly 13 includes a guide ring 131 disposed between the inner wall of the outer cylinder 1 and the inner wall of the inner cylinder 2. The axial coverage length of the guide ring 131 meets the stroke requirements of the inner cylinder 2 and the piston 3, ensuring the motion stability of the inner cylinder 2 and the piston 3. It also includes a sealing ring 132 disposed on the inner cylinder 2 and the piston 3. The guide ring 131 and the sealing ring 132 are used to ensure the motion stability of the inner cylinder 2 and the piston 3 and the hydraulic oil sealing performance. The sensor group 15 includes a displacement sensor 151 disposed on the outer cylinder 1 and the inner cylinder 2, a pressure sensor 152 disposed on the first oil passage 9 and the second oil passage 12, and a sensor for monitoring the displacement of the outer cylinder 1 and the inner cylinder 2. The valve core sensor 153 for the valve core position of the first electro-hydraulic servo valve 8 and the second electro-hydraulic servo valve 11, the displacement sensor 151 for measuring the displacement of the piston 3 relative to the outer cylinder 1 and the inner cylinder 2, the pressure sensor 152 for monitoring the pressure in each chamber, and the valve core sensor 153 for providing feedback on the actual position of the valve core; the signal input terminal of the fault detection and switching module 14 is connected to the sensor group 15, and the signal output terminal is connected to the control terminal of the first electro-hydraulic servo valve 8 and the second electro-hydraulic servo valve 11. The fault detection and switching module 14 is used to receive all sensor data in real time, and comprehensively judge whether the system is faulty by comparing the command position with the actual displacement, monitoring abnormal pressure, checking the deviation between valve command and valve feedback, and checking for no response after timeout. When a fault occurs, the system control is switched.

[0033] Specifically, under normal operating conditions: the first electro-hydraulic servo valve 8 controls the pressure of the rodless chamber and rod chamber of the outer oil chamber 5 through the first oil circuit 9, driving the inner oil cylinder 2 to slide within the outer oil cylinder 1; the second electro-hydraulic servo valve 11 controls the pressure of the rodless chamber and rod chamber of the inner oil chamber 6 through the second oil circuit 12, driving the piston 3 to slide within the inner oil cylinder 2; the two channels work together to push the piston 3 to output load force.

[0034] Fault condition: If the outer cylinder 1 system fails, such as jamming, the fault detection and switching module 14 immediately cuts off the signal of the first electro-hydraulic servo valve 8 and switches the command to the second electro-hydraulic servo valve 11. At this time, the inner cylinder 2 moves relative to the jammed outer cylinder 1 under the guidance of the guide ring 131, and the piston 3 continues to be controlled by the inner oil chamber 6 to complete bidirectional drive; the reverse is the same when the inner cylinder 2 fails.

[0035] In summary, through the nested dual-cylinder design, the outer cylinder 1 encloses the inner cylinder 2, and the inner cylinder 2 encloses the piston 3. Combined with the physically isolated first and second independent hydraulic servo units, this design reduces the space occupied compared to traditional parallel cylinder schemes while ensuring redundancy and fault tolerance. The independent motion control of the outer cylinder 1 and the inner cylinder 2 ensures that even if one cylinder jams, the other cylinder can still drive the load through the piston 3, completely solving the problem of jamming chain failure in parallel cylinders. The guide and sealing assembly 13 and the sealing ring 16 achieve multi-stage dynamic sealing, ensuring zero cross-contamination of hydraulic oil between the two chambers.

[0036] The A and B ports of the first electro-hydraulic servo valve 8 and the second electro-hydraulic servo valve 11 are strictly connected to the rodless chamber and the rod chamber respectively to ensure that the bidirectional motion capability is not lost after a single-channel failure; the fault detection and switching module 14 makes real-time decisions based on multi-source data of displacement, pressure and valve core position to achieve fast and seamless switching; the independent hydraulic source design eliminates risks from the source, and the system can still maintain good output performance when a single point of failure occurs.

[0037] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A hydraulic redundant servo control device comprising an outer cylinder (1), an inner cylinder (2) coaxially and slidingly connected inside the outer cylinder (1), and a piston member (3) provided in the inner cylinder (2), characterized in that: One end of the piston (3) is rigidly connected to the load connection end (4), and the other end is slidably connected to the inside of the inner cylinder (2); An outer oil cavity (5) is formed between the outer oil cylinder (1) and the inner oil cylinder (2), and an inner oil cavity (6) is formed inside the inner oil cylinder (2). The outer oil chamber (5) is connected to the first independent hydraulic servo unit through the first oil passage (9). The first independent hydraulic servo unit includes a first hydraulic source (7) and a first electro-hydraulic servo valve (8) connected to the first hydraulic source (7). The A port and B port of the first electro-hydraulic servo valve (8) are respectively connected to the rodless chamber and the rod chamber of the outer oil chamber (5) through the first oil passage (9). The inner oil chamber (6) is connected to the second independent hydraulic servo unit through the second oil passage (12). The second independent hydraulic servo unit includes a second hydraulic source (10) and a second electro-hydraulic servo valve (11) connected to the second hydraulic source (10). The A port and B port of the second electro-hydraulic servo valve (11) are respectively connected to the rodless chamber and the rod chamber of the inner oil chamber (6) through the second oil passage (12). The second independent hydraulic servo unit controls the piston (3) to move in the inner cylinder (2), and the first independent hydraulic servo unit controls the inner cylinder (2) to move in the outer cylinder (1).

2. A hydraulic redundant servo control device according to claim 1, characterized in that: It also includes a guide and sealing assembly (13), which includes a guide ring (131) disposed between the inner wall of the outer cylinder (1) and the inner wall of the inner cylinder (2), and a sealing ring (132) disposed on the inner cylinder (2) and the piston (3).

3. The hydraulic redundant servo control device of claim 1, wherein: It also includes a sensor group (15), which includes a displacement sensor (151) disposed on the outer cylinder (1) and the inner cylinder (2), a pressure sensor (152) disposed on the first oil circuit (9) and the second oil circuit (12), and a valve core sensor (153) for monitoring the valve core position of the first electro-hydraulic servo valve (8) and the second electro-hydraulic servo valve (11).

4. The hydraulic redundant servo control device according to claim 1 or 3, characterized by: It also includes a fault detection and switching module (14), the signal input terminal of which is connected to the sensor group (15), and the signal output terminal is connected to the control terminals of the first electro-hydraulic servo valve (8) and the second electro-hydraulic servo valve (11).

5. The hydraulic redundant servo control device of claim 2, wherein: The axial coverage length of the guide ring (131) meets the stroke requirements of the inner cylinder (2) and the piston (3).

6. The hydraulic redundant servo control device of claim 1, wherein: The first hydraulic source (7) and the second hydraulic source (10) are physically isolated independent hydraulic pump stations, or hydraulic branch circuits with independent accumulators and isolation valves drawn from the same power source.

7. The hydraulic redundant servo control device of claim 1, wherein: Both the outer cylinder (1) and the inner cylinder (2) are provided with sealing rings (16) between themselves and the piston (3).

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