CN103321975B - A kind of low-high pressure soft start hydraulic oil source system - Google Patents

Abstract

The invention belongs to the oil source design technology of a hydraulic system, and specifically discloses a low-high pressure soft-start hydraulic oil source system, which includes a system high pressure pipe and a system oil return pipe respectively connected to an oil tank, and the system high pressure pipe is sequentially connected to a high pressure filter device, one-way valve, high-pressure hose, main pump, low-pressure hose and butterfly valve, and the oil return port of the oil tank is connected to the system oil return pipe through the oil return filter and cooler in turn; There is a low-voltage soft-start module between them. It can reduce the pressure pulse caused by high-pressure oil to all pipelines and valves in the high-pressure circuit of the system, effectively reduce the peak value of the pulse, thereby reducing the impact on each component in the system, and greatly improving the reliability of use; The impact of the original design of the sealing structure is also greatly reduced, which effectively prevents impact noise and local leakage caused by the hydraulic oil source, and greatly increases the service life of the hydraulic oil source.

Description

A low-high pressure soft start hydraulic oil source system

technical field

The invention belongs to the hydraulic system oil source design technology, in particular to a hydraulic oil source.

Background technique

Hydraulic systems are widely used in aerospace, military industry, transportation, and ships due to their small size and mass, large power-to-weight ratio, easy to realize reciprocating motion, easy to realize large-scale continuously variable speed, stable transmission, long service life, and easy operation. , mining and other industrial fields.

As the power source of the hydraulic system, the hydraulic oil source provides sufficient high-pressure oil for actuators and other actuators, and controls the actuators to perform specified actions through control components such as servo valves. It is an important part of the hydraulic system. The performance of the hydraulic oil source directly determines whether the design function of the hydraulic system can be realized. An oil source with excellent performance and reasonable design will have a crucial impact on the performance, life, cost of use and maintenance intensity of the entire system. In the performance assessment of the oil source, the system pressure shock caused by the pump opening process is an important indicator of the performance of the oil source.

The hydraulic oil source mainly includes components such as pumps, motors, oil tanks, filters, overflow valves, hydraulic pipelines and various functional valves, among which the pumps are connected to the motors through couplings. When working, the motor drives the pump to run synchronously through the high-speed rotation of the shaft, and outputs high-pressure oil to the control and actuator through components such as pipelines, filters, valves, etc., and converts electrical energy into mechanical energy to realize the functions of the hydraulic system. When the motor is turned on, its speed rises rapidly in a short period of time, driving the oil pump to output a large amount of high-pressure oil to the hydraulic system instantaneously, forming a pressure peak, which can reach twice the pump output pressure. The components cause a huge impact, which seriously affects and damages the internal structure and seal of the components, resulting in the failure of the partial seal of the system and the wear of the components, causing impact noise and partial leakage of the hydraulic oil source, which greatly shortens the service life of the hydraulic oil source. If the shock is severe, it may cause the oil source function to fail and fail to work normally. When the actuator is severely impacted, it may cause malfunction, which may damage the connecting parts and even cause safety accidents. This phenomenon is especially obvious in high-pressure and large-flow hydraulic oil sources, which has great potential safety hazards.

Contents of the invention

The purpose of the present invention is to provide a low-high pressure soft-start hydraulic oil source system that can reduce the impact loss of components, increase their service life, and have high reliability.

Technical scheme of the present invention is as follows:

A low-high pressure soft start hydraulic oil source system, which includes a system high pressure pipe and a system oil return pipe respectively connected to the oil tank, the low-high pressure soft start hydraulic oil source system also includes a main pump, the control of the main pump The oil port is connected to the oil inlet of the pressure regulating valve, and the oil outlet of the pressure regulating valve is connected to the fuel tank; the oil suction port of the main pump is connected to the oil suction port of the fuel tank through a low pressure hose and a butterfly valve, and the oil suction port of the main pump The high-pressure oil port is connected to the system high-pressure pipe through a high-pressure hose, a check valve and a high-pressure filter; the oil return port of the oil tank is connected to the system oil return pipe through an oil return filter and a cooler in turn; it is characterized in that: the A low-high pressure soft start module is provided between the oil return pipe of the system and the high pressure pipe of the system. The low-high pressure soft start module includes a hydraulic control pilot relief valve, an accumulator and a throttle valve. The oil port is connected to the high-pressure pipe of the system, the oil discharge port of the hydraulic control pilot relief valve is connected to the oil return pipe of the system, and the external control oil port of the hydraulic control pilot relief valve is connected to the high-pressure pipe of the system through an accumulator and a throttle valve.

In the aforementioned low-high pressure soft-start hydraulic oil source system, the oil tank is also provided with an oil drain valve, a liquid level gauge and an air filter.

In the aforementioned low-high pressure soft start hydraulic oil source system, a pressure sensor and an accumulator are arranged in parallel in bypass between the low-high pressure soft start module and the high pressure filter.

In the aforementioned low-high pressure soft-start hydraulic oil source system, the oil port of the accumulator is provided with a cut-off valve.

In the above-mentioned low-high pressure soft-start hydraulic oil source system, an electromagnetic reversing valve is provided between the control oil port of the main pump and the oil inlet of the pressure regulating valve, and the oil inlet of the electromagnetic reversing valve The port is connected with the control oil port of the main pump, the oil outlet is connected with the oil tank when the electromagnetic reversing valve is not powered, and the oil outlet is connected with the oil inlet of the pressure regulating valve when it is powered.

The notable effect of the present invention is that: the low-high pressure soft start module added on the basis of the prior art of the present invention can reduce the pressure pulse caused by the high pressure oil to all components such as pipelines and valves in the high pressure circuit of the system, effectively Reduce the peak value of the pulse, thereby reducing the impact on each component in the system, and greatly improving the reliability of use; at the same time, the impact on the original design of the system's sealing structure is also greatly reduced, effectively preventing impact noise and local leakage caused by the hydraulic oil source. The service life of the hydraulic oil source is greatly increased.

Further, after the control oil port of the main pump is connected with the pressure regulating valve through the electromagnetic reversing valve, the working loss of the main pump can be reduced and the service life of the main pump can be increased.

Further, a pressure sensor and an accumulator are installed in parallel between the low-high pressure soft start module and the high pressure filter, which can measure the pressure of the high pressure pipe of the system in real time and absorb the pressure pulsation generated by the main pump, thereby further stabilizing the output of the high pressure pipe oil pressure.

Description of drawings

Fig. 1 is a schematic diagram of a low-high pressure soft start hydraulic oil source system;

In the figure: 1. Oil tank; 2. Oil drain valve; 3. Liquid level gauge; 4. Air filter; 5. Butterfly valve; 6. Low pressure hose; 7. Main pump; 8. Motor; 9. High pressure hose ;10. One-way valve; 11. High pressure filter; 12. Electromagnetic reversing valve; 13. Pressure regulating valve; 14. Globe valve; 15. Pressure sensor; 16. Accumulator; 17. Throttle valve; 18. Accumulator; 19. Hydraulic control pilot relief valve; 20. Oil return filter; 21. Cooler; 22. System high pressure pipe; 23. System oil return pipe; 24. Low-high pressure soft start module.

detailed description

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 1, the low-high pressure soft-start hydraulic oil source system of the present invention includes the main pump 7 driven by the motor 8, the control oil port X of the main pump 7 is connected with the oil inlet port of the electromagnetic reversing valve 12, the described The electromagnetic reversing valve 12 is a two-position three-way valve, wherein the oil outlet is connected with the fuel tank 1 when it is not powered, and the oil outlet is connected with the oil inlet of the pressure regulating valve 13 when it is powered. The oil outlet of the pressure regulating valve is connected with the oil tank 1 .

The control oil port X of the main pump 1 can also be directly connected to the oil inlet port of the pressure regulating valve 13 . However, after the electromagnetic reversing valve 12 is connected with the pressure regulating valve 13, the working loss of the main pump 7 can be reduced and its service life can be increased.

The oil suction port of the main pump 7 is connected to the oil suction port of the fuel tank 1 through the low-pressure hose 6 and the butterfly valve 5, and the oil drain valve 2, the liquid level gauge 3 and the air filter 4 are installed on the described fuel tank 1. The oil return port of the oil tank 1 is connected to the system oil return pipe 23 through the oil return filter 20 and the cooler 21 in sequence.

The high-pressure oil port of the main pump 7 is connected with the system high-pressure pipe 22 through a high-pressure hose 9 , a check valve 10 and a high-pressure filter 11 .

A low-high pressure soft-start module 24 is installed between the system oil return pipe 23 and the system high-pressure pipe 22. The low-high pressure soft-start module 24 includes a hydraulic control pilot relief valve 19, and its oil inlet is connected to the system high-pressure pipe 22. connected, the oil discharge port is connected to the system oil return pipe 23, and the hydraulic control pilot relief valve 19 is an externally controlled hydraulic control pilot relief valve 19, so on the external control oil port of the hydraulic control pilot relief valve 19 It is connected to the system high-pressure pipe 22 through the accumulator 18 and the throttle valve 17 .

The pressure sensor 15 and the accumulator 16 can also be installed in parallel between the low-high pressure soft start module 24 and the high pressure filter 11. In order to facilitate the maintenance of the accumulator 16, a cut-off valve can be installed at the oil port of the accumulator 16. valve 14. If this installation method is adopted, the pressure sensor 15 can measure the pressure of the system high-pressure pipe 22 in real time, and the accumulator 16 can absorb the pressure pulsation generated by the main pump 7, and can further stabilize the output oil pressure of the high-pressure pipe.

The working process is as follows:

Before working, the pressure regulating valve 13 will set a target pressure value and start the motor 8. At this time, the electromagnetic reversing valve 12 is not powered, and the oil in the control oil port X of the main pump 7 is discharged back to the oil tank 1 through the electromagnetic reversing valve 12. . At this time, the system high-pressure pipe 22 has no high-pressure oil output. Afterwards, the electromagnetic reversing valve 12 is energized, the main pump 7 starts to work under load, and the main pump 7 starts to output high-pressure oil. At this time, in the low-high pressure soft start module 24, due to the energy storage effect of the accumulator 18 and the damping effect of the throttle valve 17, the pressure of the oil in the pipeline where the accumulator 18 and the throttle valve 17 are located increases slowly, and the As the pressure of this pipeline rises gradually, the opening pressure of the spool of hydraulic control pilot relief valve 19 rises accordingly. The spool of the pilot overflow valve 19 is opened to unload the pressure of the high pressure pipe 22 of the system. Therefore, the pressure of the system high-pressure pipe 22 gradually rises slowly with the pressure of the pipeline where the accumulator 18 and the throttle valve 17 are located, until the pressure of the pipeline where the accumulator 18 and the throttle valve 17 are located rises to the above-mentioned regulation. The target pressure value set by the pressure valve 13, the spool of the hydraulic control pilot relief valve 19 is closed, the pressure unloading in the high pressure pipe 22 of the system is stopped, the entire soft start process is completed, and normal work begins.

For example, the target pressure of the pressure regulating valve 13 is set to 21 MPa, and when the hydraulic oil source is turned on, the motor 8 drives the main pump 7 to output 21 MPa high-pressure oil. At this time, there is no pressure at the external control oil port of the hydraulic control pilot relief valve 19, and the spool of the hydraulic control pilot relief valve 19 is opened, and the oil liquid all overflows, and the pressure of the system high pressure pipe 22 cannot increase. Simultaneously, the line pressure between the system high-pressure pipe 22 and the throttle valve 17 rises to 21 MPa instantaneously. Due to the damping effect of the throttle valve 17, a pressure difference is formed between the front and rear of the throttle valve 17, and the pressure in the pipeline between the throttle valve 17 and the accumulator 18 rises relatively slowly from 0 to less than 21 MPa, that is The pressure at the oil port of the accumulator 18 rises from 0 to less than 21 MPa, and the accumulator 18 begins to store high-pressure oil, thus causing the pipeline pressure between the accumulator 18 and the hydraulic control pilot relief valve 19 to rise slowly, and The pressure at the control oil port of the hydraulic control pilot relief valve 19 rises slowly. As the pressure here rises, the opening pressure of the hydraulic control pilot relief valve 19 begins to rise, the main spool closes, the system stops overflowing, and the system pressure rises to the level controlled by the hydraulic control pilot relief valve 19. The pressure at the port is consistent. When the accumulator 18 stops storing high-pressure oil, the pressure in the pipeline where the accumulator 18 and the throttle valve 17 are located gradually stops changing and is fixed at 21 MPa. At this moment, the opening pressure of the hydraulic control pilot relief valve 19 is 21MPa. At this point, the low-high pressure soft start is completed, the system starts to work normally, most of the pressure shocks when the oil source is started are eliminated, and the components in the system are basically free from shocks.

Claims (4)

1. A low-high pressure soft-start hydraulic oil source system, which includes a system high-pressure pipe (22) and a system oil return pipe (23) connected to the oil tank (1) respectively, and the low-high pressure soft-start hydraulic oil source system It also includes a main pump (7), the control oil port of the main pump (7) is connected with the oil inlet of the pressure regulating valve (13), and the oil outlet of the pressure regulating valve (13) is connected with the fuel tank (1); The oil suction port of the main pump (7) is connected with the oil suction port of the oil tank (1) through the low-pressure hose (6) and the butterfly valve (5), and the high-pressure oil port of the main pump (7) is connected with the high-pressure hose (9) ), check valve (10) and high-pressure filter (11) are connected with system high-pressure pipe (22); the oil return port of the oil tank (1) passes through oil return filter (20) and cooler (21) and The system oil return pipe (23) is connected; it is characterized in that: a low-high pressure soft start module (24) is provided between the system oil return pipe (23) and the system high pressure pipe (22), and the low-high pressure soft start The module (24) includes the hydraulic control pilot relief valve (19), the first accumulator (18) and the throttle valve (17), the oil inlet of the hydraulic control pilot relief valve (19) and the system high pressure pipe (22) connection, the oil discharge port of the hydraulic control pilot relief valve (19) is connected to the system oil return pipe (23), and the external control oil port of the hydraulic control pilot relief valve (19) passes through the first accumulator (18) and throttling The valve (17) is connected with the system high-pressure pipe (22). 2. A low-high pressure soft start hydraulic oil source system as claimed in claim 1, characterized in that: the oil tank (1) is also provided with an oil drain valve (2), a liquid level gauge (3) and an air filter cleaner (4). 3. A low-high-pressure soft-start hydraulic oil source system according to claim 1 or 2, characterized in that: the bypass between the low-high-pressure soft-start module (24) and the high-pressure filter (11) A pressure sensor (15) and a second accumulator (16) are arranged in parallel. 4. A low-high pressure soft-start hydraulic oil source system as claimed in claim 1 or 2, characterized in that: between the control oil port of the main pump (7) and the oil inlet port of the pressure regulating valve (13) An electromagnetic reversing valve (12) is arranged between them, and the oil inlet of the electromagnetic reversing valve (12) is connected with the control oil port of the main pump (7). The oil port is connected with the fuel tank (1), and the oil outlet is connected with the oil inlet of the pressure regulating valve (13) when energized.