A six-degree-of-freedom hydraulic pressure balancing device

Abstract

The present invention discloses a six-degree-of-freedom hydraulic pressure balancing device, comprising a lower platform and an upper platform arranged above the lower platform, wherein six hydraulic cylinders for providing follow-up support for the movement of the upper platform are arranged between the lower platform and the upper platform, and the six hydraulic cylinders form a six-degree-of-freedom structure; the hydraulic cylinder is a double-acting oil cylinder including a rod chamber and a rodless chamber located below the rod chamber; the hydraulic cylinder is connected to an accumulator. The present invention adopts the closed hydraulic support principle, which can not only achieve zero loss of hydraulic oil, greatly reduce the energy consumption of the electric actuator for supporting the load mass and the mass of the motion frame, reduce the peak power demand of the actuator, and make full use of the rated performance of the user's actuator, realize the system energy saving and emission reduction, cost reduction and equipment service life improvement requirements, but also realize the hydraulic rigid locking of the motion platform.

Description

Technical Field

[0001] The present invention relates to the technical field of multi-degree-of-freedom motion platforms, and in particular to a six-degree-of-freedom hydraulic pressure balancing device applicable to a heavy-load motion platform. Background Art

[0002] In the field of multi-degree-of-freedom motion platforms, as the platform load demand becomes larger and larger, the weight and size of the motion structure frame required to support the load are also increasing. As a result, the load mass and motion frame mass often account for more than 60% of the total dynamic load of the platform. Therefore, the electric actuator used to drive the platform will consume most of the power to support the load mass and the motion frame mass, resulting in a large amount of ineffective energy consumption.

[0003] In the prior art, there are force balancing devices for motion platforms, and commonly used ones include single-cylinder gas spring type, double-cylinder gas spring type, triple-cylinder gas spring type and metal mechanical spring type. There is also a guided single hydraulic cylinder accumulator type. The principle is to use elastic components to support the motion platform and allow it to move unconstrainedly. Although it can offset the entire weight, the structure is complex and there is no safety locking capability. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a six-degree-of-freedom hydraulic pressure balancing device, which can reduce the power consumption of the electric actuator for supporting the load mass and the motion frame mass.

[0005] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows.

[0006] A six-degree-of-freedom hydraulic pressure balancing device comprises a lower platform and an upper platform arranged above the lower platform, wherein six hydraulic cylinders are arranged between the lower platform and the upper platform for providing follow-up support for the movement of the upper platform, and the six hydraulic cylinders form a six-degree-of-freedom structure; the hydraulic cylinder is a double-acting cylinder comprising a rod chamber and a rodless chamber located below the rod chamber; the hydraulic cylinder is connected to an accumulator.

[0007] Preferably, the piston rod at the upper portion of the hydraulic cylinder is connected to the lower surface of the upper platform via an upper hinge, and the lower end of the hydraulic cylinder is connected to the upper surface of the lower platform via a lower hinge.

[0008] Preferably, the rod chamber oil port of each hydraulic cylinder is connected to a rod chamber switch valve for controlling the free movement and rigid locking of the corresponding hydraulic cylinder through a rod chamber hydraulic hose; the rodless chamber oil port of each hydraulic cylinder is connected to a rodless chamber switch valve for controlling the free movement and rigid locking of the corresponding hydraulic cylinder through a rodless chamber hydraulic hose; the six rod chamber switch valves and the six rodless chamber switch valves are connected to the hydraulic end of the accumulator through an oil source hose.

[0009] Preferably, the rod-cavity switch valve and the rodless cavity switch valve are both solenoid valves, and the controlled ends of the rod-cavity switch valve and the rodless cavity switch valve are connected to electric actuators.

[0010] Preferably, the upper surface of the lower platform is provided with a hydraulic valve block for installing a rod chamber switch valve and a rodless chamber switch valve.

[0011] Preferably, the airbags of the accumulator are pre-filled with gas; the closed cavity formed by the hydraulic end of the accumulator, six hydraulic cylinders, six rodless cavity hydraulic hoses, six rod cavity hydraulic hoses, the oil source hose, the hydraulic valve block, the rod cavity switching valve and the rodless cavity switching valve is pre-filled with hydraulic oil; the difference between the total volume of the hydraulic oil in the closed cavity when the six hydraulic cylinders are in an extended state and the total volume of the hydraulic oil in the closed cavity when the six hydraulic cylinders are in a contracted state is less than the total compressible amount of the pre-filled gas in the airbags of the accumulator.

[0012] Preferably, an oil filling and discharging assembly for filling and discharging oil in the closed cavity is also provided on the upper surface of the lower platform.

[0013] Due to the adoption of the above technical scheme, the technical progress achieved by the present invention is as follows.

[0014] The present invention can not only offset the entire weight of the load and the motion frame, but also has a compact structure. It adopts the closed hydraulic support principle and utilizes the elastic compression characteristics of the pre-filled gas in the accumulator and the hydraulic oil as a pressurized closed hydraulic circulation oil source. The hydraulic system is in a completely closed state, and the hydraulic oil is lost nothing. When the equipment is working, the supporting hydraulic cylinder moves with the electric platform and realizes the function of follow-up support, thereby greatly reducing the energy consumption of the electric actuator, which is conducive to further pushing the motion platform to move in space through the actuator, reducing the peak power demand of the actuator, and making the maximum use of the working characteristics of the actuator under the rated capacity, so that the rated performance of the user's actuator is fully utilized, and the system energy saving and emission reduction, cost reduction and equipment service life improvement requirements are achieved. At the same time, the device has the ability to safely lock the motion equipment, and can realize the hydraulic rigid locking of the motion platform by cutting off the hydraulic switch valve, so as to avoid the motion platform entering an unstable and dangerous posture when the actuator stops or loses control, thereby increasing the system's working reliability and maintainability and reducing the cost of use.

[0015] In the application field of motion platforms with axial compression loads, the present invention combines a parallel six-degree-of-freedom hydraulic cylinder and a hydraulic energy storage fluid to optimize the dynamic performance of the vertical actuator, thereby solving the problem of imbalance of compression and extension axial forces when the vertical drive actuator is working under certain conditions, reducing the peak force output of the vertical actuator, improving the dynamic performance of the actuator force output, reducing working noise, extending the service life of the equipment, and improving the safety locking and protection capabilities of the motion platform, and greatly reducing the production, maintenance and use costs of the application equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the present invention;

[0017] Figure 2 It is a simplified schematic diagram of the structure of the present invention from top view;

[0018] Figure 3 It is a simplified structural schematic diagram of the side view of the present invention.

[0019] Among them: 101. Hydraulic cylinder, 201. Rod chamber switch valve, 301. Rodless chamber switch valve, 401. Accumulator, 501. Hydraulic valve block, 6. Oil charging and discharging assembly, 701. Upper hinge, 801. Lower hinge, 9. Lower platform, 10. Upper platform, 411. Rod chamber hydraulic hose, 421. Rodless chamber hydraulic hose, 431. Oil source hose. DETAILED DESCRIPTION

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] A six-degree-of-freedom hydraulic pressure balancing device, combined with Figures 1 to 3 As shown, it includes a lower platform 9, an upper platform 10, six hydraulic cylinders 101 and an accumulator 401, wherein the lower platform 9 is a fixed platform; the upper platform 10 is arranged above the lower platform 9 and is a moving platform for loads; the six hydraulic cylinders 101 are arranged between the lower platform 9 and the upper platform 10, and are used to generate follow-up support for the movement of the upper platform 10; the accumulator 401 can be arranged on the upper surface of the lower platform 9 or other places according to needs, and the accumulator 401 is connected to the six hydraulic cylinders 101, and is used to drive the telescopic movement of the piston rod of the hydraulic cylinder 101.

[0022] The six hydraulic cylinders 101 are all double-acting oil cylinders, including a rod chamber and a rodless chamber, wherein the rodless chamber is located at the lower part of the rod chamber. The piston rod at the upper part of the hydraulic cylinder 101 is connected to the lower surface of the upper platform 10 through the upper hinge 701, and the lower end of the hydraulic cylinder 101 is connected to the upper surface of the lower platform 9 through the lower hinge 801, forming a six-degree-of-freedom structure.

[0023] The rod chamber oil port of each hydraulic cylinder 101 is connected to a rod chamber switch valve 201 through a rod chamber hydraulic hose 411; the rodless chamber oil port of each hydraulic cylinder 101 is connected to a rodless chamber switch valve 301 through a rodless chamber hydraulic hose 421. There are two accumulators 401, namely the first accumulator and the second accumulator. The six rod chamber switch valves 201 are connected to the hydraulic end of the first accumulator through an oil source hose 431, and the six rodless chamber switch valves 301 are connected to the hydraulic end of the second accumulator through an oil source hose 431. The six rod chamber switch valves 201 and the six rodless chamber switch valves 301 are all solenoid valves, and the controlled end is connected to an electric actuator, which controls the on-off of the oil circuit under the control of the electric actuator.

[0024] A hydraulic valve block 501 is disposed on the upper surface of the lower platform 9. The hydraulic valve block 501 has the characteristics of compact structure, convenient maintenance, installation, adjustment and replacement of hydraulic components, and can be provided in multiple numbers according to needs. In this embodiment, three hydraulic valve blocks 501 are selected, and the rod chamber switch valve 201 and the rodless chamber switch valve 301 on two adjacent hydraulic cylinders 101 are installed as a group on one hydraulic valve block 501.

[0025] The airbags of the accumulator 401 are all pre-filled with gas of a certain pressure. The closed cavity formed by the hydraulic end of the accumulator 401, the six hydraulic cylinders 101, the six rodless cavity hydraulic hoses 421, the six rod cavity hydraulic hoses 411, the oil source hose 431, the hydraulic valve block 501, the rod cavity switch valve 201 and the rodless cavity switch valve 301 is pre-filled with hydraulic oil, and the oil filling pressure can exceed the accumulator charging pressure, and the difference between the total volume of hydraulic oil in the closed cavity when the six hydraulic cylinders 101 are in the extended state and the total volume of hydraulic oil in the closed cavity when the six hydraulic cylinders 101 are in the contracted state is less than the total compressible amount of the pre-filled gas in the airbags of the accumulator 401. When the six hydraulic cylinders 101 are in the extended state, the oil filling pressure in the closed cavity is greater than the charging pressure of the accumulator 401.

[0026] When all the rod chamber switch valves 201 and the rodless chamber switch valves 301 are opened under the control of the electric actuator, the six hydraulic cylinders 101 enter the working state, and the gravity generated by the upper platform 10 and its load can be offset by the support of the hydraulic cylinders 101. The support force of the hydraulic cylinders 101 depends on the pre-charged gas pressure and pre-charged hydraulic oil pressure of the accumulator. When working, the switch valve is in the open state, and the six hydraulic cylinders 101 follow the upper platform 10 to move (the upper platform 10 is driven by the electric actuator), and at the same time realize the load gravity compensation function of the upper platform 10. The premise for the six hydraulic cylinders 101 to work reliably is that the effective volume of the accumulator is greater than the volume change of the hydraulic cavity generated by the extension and contraction of the six hydraulic cylinders 101. When the equipment is in a shutdown or safe state, all the rod chamber switch valves 201 and the rodless chamber switch valves 301 can be closed, so that the upper platform 10 is in a hydraulic rigid locking state.

[0027] The upper surface of the lower platform 9 is also provided with an oil filling and discharging assembly 6, which is used to fill and discharge oil in the closed cavity.

[0028] When the present invention is in use, in normal operation, the rod chambers of the six hydraulic cylinders 101 are connected to a rod chamber switch valve 201 to the first accumulator, and the rodless chambers of the six hydraulic cylinders 101 are respectively connected to a rodless chamber switch valve 301 to the second accumulator; when the rod chamber switch valve 201 and the rodless chamber switch valve 301 are opened, the oil circuit is unblocked, and the piston of the hydraulic cylinder 101 moves freely following the upper platform 10. At this time, the hydraulic oil pre-filled in the hydraulic circuit drives the piston rod of the hydraulic cylinder 101 to move upward under the push of the compressed gas in the accumulator airbag, thereby generating a follow-up support for the moving upper platform 10.

[0029] When the six hydraulic cylinders 101 stop working, the rod chamber switch valve 201 and the rodless chamber switch valve 301 are closed, the oil circuit is locked, and the hydraulic oil in the rod chamber and the rodless chamber of the hydraulic cylinder 101 cannot be compressed and flowed, thereby achieving rigid locking of the moving upper platform 10.

[0030] The present invention has been applied to a heavy-load multi-degree-of-freedom simulator with a load of three tons to simulate heavy truck driving training, and has produced beneficial effects.

Claims

1. A six-degree-of-freedom hydraulic pressure balancing device, comprising a lower platform (9) and an upper platform (10) arranged above the lower platform (9), characterized in that: Six hydraulic cylinders (101) are arranged between the lower platform (9) and the upper platform (10) to provide follow-up support for the movement of the upper platform (10), and the six hydraulic cylinders form a six-degree-of-freedom structure; the hydraulic cylinder (101) is a double-acting oil cylinder including a rod chamber and a rodless chamber located below the rod chamber; the hydraulic cylinder (101) is connected to an accumulator (401); The rod chamber oil port of each hydraulic cylinder (101) is connected to a rod chamber switch valve (201) for controlling the free movement and rigid locking of the corresponding hydraulic cylinder (101) through a rod chamber hydraulic hose (411); the rodless chamber oil port of each hydraulic cylinder (101) is connected to a rodless chamber switch valve (301) for controlling the free movement and rigid locking of the corresponding hydraulic cylinder (101) through a rodless chamber hydraulic hose (421); the six rod chamber switch valves (201) and the six rodless chamber switch valves (301) are connected to the hydraulic end of the accumulator (401) through an oil source hose (431); the upper surface of the lower platform (9) is provided with a hydraulic valve block (501) for installing the rod chamber switch valve (201) and the rodless chamber switch valve (301); The airbags of the accumulator (401) are all pre-filled with gas; the closed cavity formed by the hydraulic end of the accumulator (401), six hydraulic cylinders (101), six rodless cavity hydraulic hoses (421), six rod cavity hydraulic hoses (411), the oil source hose (431), the hydraulic valve block (501), the rod cavity switch valve (201) and the rodless cavity switch valve (301) is pre-filled with hydraulic oil; the difference between the total volume of hydraulic oil in the closed cavity when the six hydraulic cylinders (101) are in an extended state and the total volume of hydraulic oil in the closed cavity when the six hydraulic cylinders (101) are in a contracted state is less than the total compressible amount of the pre-filled gas in the airbags of the accumulator (401).

2. A six-degree-of-freedom hydraulic pressure balancing device according to claim 1, characterized in that: The piston rod at the upper part of the hydraulic cylinder (101) is connected to the lower surface of the upper platform (10) via an upper hinge (701), and the lower end of the hydraulic cylinder (101) is connected to the upper surface of the lower platform (9) via a lower hinge (801).

3. A six-degree-of-freedom hydraulic pressure balancing device according to claim 1, characterized in that: The rod chamber switch valve (201) and the rodless chamber switch valve (301) are both solenoid valves, and the controlled ends of the rod chamber switch valve (201) and the rodless chamber switch valve (301) are connected to electric actuators.

4. A six-degree-of-freedom hydraulic pressure balancing device according to claim 1, characterized in that: The upper surface of the lower platform (9) is also provided with an oil filling and discharging assembly (6) for filling and discharging oil in the closed cavity.

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