Hydraulic excavator pressure stabilizing system based on throttle control and method of use

Abstract

Based on throttle control's hydraulic excavator steady voltage system and use method, main pump is connected with pump control proportional valve YI, and the connecting end of reversing valve is connected with proportional valve YII and proportional valve YIII respectively, and the oil inlet end of reversing valve is connected with check valve CPII, check valve CPI and oil return control valve, and the oil outlet end of reversing valve is connected with oil inlet control valve and oil cylinder, and one end of oil inlet control valve is connected with proportional valve YIV, and pilot pump is connected with pilot control valve through pilot filter.The hydraulic excavator steady voltage system based on throttle control and use method of the present application, through the hydraulic excavator starting, preheating the hydraulic oil to reach the set temperature, then making the main pressure oil bypassing the valve core oil return, flowing through the oil inlet control valve throttling buffer, thereby reducing the hydraulic starting impact, at the same time, the controller controls the oil return control valve to be electrified, makes the throttling oil level be at the working oil level, increases the back pressure of oil return, reduces the oil return impact.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of engineering machinery, in particular to a hydraulic excavator pressure stabilizing system based on throttle control and a use method thereof. BACKGROUND

[0002] The hydraulic system is the core technology of the hydraulic excavator. With the rapid and efficient demand of the hydraulic excavator market, the hydraulic technology of the excavator is developing towards high speed, high pressure and large flow, and the pulsation and pressure impact of the hydraulic system become one of the important factors hindering the progress of the hydraulic technology, which also seriously affects the health of people and the service life of mechanical equipment.

[0003] The existing traditional hydraulic excavator reduces the system impact by matching the valve core opening degree and the main pump flow when starting, stopping and working in harsh conditions. Due to the characteristics of high speed, high pressure and large flow of the hydraulic system, the pressure pulsation and impact of the hydraulic excavator during starting, stopping and harsh conditions cannot be effectively eliminated. SUMMARY

[0004] The technical problem to be solved by the present application is to overcome the shortcomings of the prior art and provide a hydraulic excavator pressure stabilizing system based on throttle control and a use method thereof, which is simple to operate and has good effect.

[0005] The present application is realized by the following technical scheme: a hydraulic excavator pressure stabilizing system based on throttle control, comprising a main pump, wherein the main pump is connected with a pump control proportional valve Y I, the main pump is connected with a cylinder through a reversing valve, the connecting end of the reversing valve is connected with a proportional valve Y II and a proportional valve Y III, respectively, the oil inlet end of the reversing valve is connected with a check valve CP II, a check valve CP I and a return oil control valve, the check valve CP II and the check valve CP I are connected together with the main pump, the oil outlet end of the reversing valve is connected with an oil inlet control valve and a cylinder, one end of the oil inlet control valve is connected with a proportional valve Y IV, and the system further comprises a pilot pump, wherein the pilot pump is connected with a pilot control valve through a pilot filter.

[0006] Further, the pump control proportional valve Y I, the proportional valve Y II, the proportional valve Y III, the return oil control valve, the oil inlet control valve, the proportional valve Y IV and the pilot control valve are connected with a controller.

[0007] The reversing valve is a three-position six-way pilot reversing valve.

[0008] The main pump is connected together with the oil inlet control valve through the bypass of the reversing valve.

[0009] The other end of the oil inlet control valve is connected with an oil tank.

[0010] The method for using the hydraulic excavator pressure stabilizing system based on throttle control comprises the following steps:

[0011] S1, the engine starts, the main pump is in working condition, the main pressure oil passes through the check valve CPI to the reversing valve,

[0012] and through the central bypass oil passage of the reversing valve to the oil inlet control valve to return to the oil tank;

[0013] S2, if the hydraulic oil temperature is lower than the set value at this time, the controller controls the oil inlet control valve to make its throttling position at the working oil level, when the hydraulic oil temperature reaches the set temperature, the controller controls the oil inlet control valve to make its passage enter the working oil level;

[0014] S3, the pilot oil provided by the pilot pump passes through the pilot filter to reach the pilot control valve, after the hydraulic oil temperature reaches the set temperature, the pilot control valve is powered on, the pilot oil passes through the pilot control valve working oil level to enter the oil inlet port of the proportional valve YII and the proportional valve YIII at both ends of the reversing valve;

[0015] S4, the electric control handle is actuated, the controller controls the proportional valve YII or the proportional valve YIII to be powered on, the pilot control oil enters the left end or the right end of the reversing valve through the proportional valve YII or the proportional valve YIII, and pushes the reversing valve into the working oil level, at this time, the main pressure oil enters the oil cylinder through the main pump, the check valve CPII, the reversing valve oil passage, and the oil cylinder is extended or retracted;

[0016] S5, if the oil cylinder is extended at this time, the hydraulic oil in the small cavity of the oil cylinder returns to the tank through the reversing valve and the oil return control valve throttling oil passage, and the oil cylinder action is completed;

[0017] S6, at the moment of starting the hydraulic excavator, the controller controls the oil inlet control valve to make its throttling position at the working oil level, at this time, the main pressure oil provided by the main pump passes through the check valve CPI, the central bypass of the reversing valve, the oil inlet control valve throttling position and returns to the tank, so as to reduce the hydraulic starting impact caused by the main pressure oil; at the same time, the controller controls the oil return control valve to make its throttling position at the working oil level, increases the back pressure of the oil return, and reduces the oil return impact;

[0018] S7, after the start is completed, the controller controls the oil inlet control valve to make its intermediate cut-off position at the working oil level, and the controller controls the oil return control valve to make its passage at the working oil level, so that the main pressure oil provided by the main pump is completely supplied to the oil cylinder of the actuator.

[0019] When the hydraulic excavator works in harsh conditions, the controller controls the oil inlet control valve to make its throttling position at the working oil level, and the oil inlet bypass of the reversing valve returns to oil, so as to reduce the pressure fluctuation caused by the external load and the change of execution speed.

[0020] When the electric control handle returns to the neutral position and the hydraulic excavator stops working, the controller controls the pump control current of the pump control proportional valve YⅠ to the set value, reducing the output flow of the main pump. At the same time, it controls the throttling oil level of the inlet control valve to the working oil level, reducing the control current of the proportional valve YⅡ or proportional valve YⅢ to reduce the pilot control pressure output by the valve. The directional valve returns to the neutral position. The main pressure oil provided by the main pump is transferred to the central bypass oil circuit through the oil circuit of the directional valve, and then returns to the oil tank through the throttling oil level of the inlet control valve, thereby reducing the impact of the excavator stopping.

[0021] The present invention has the following advantages: The hydraulic excavator pressure stabilization system and its usage method based on throttling control of the present invention preheat the hydraulic oil to a set temperature when the hydraulic excavator is started. Then, the main pressure oil flows through the valve core bypass return oil and then through the inlet control valve for throttling and buffering, thereby reducing the hydraulic start-up impact. At the same time, the controller controls the return oil control valve to be energized, so that its throttling oil level is at the working oil level, increasing the return oil back pressure and reducing the return oil impact. Attached Figure Description

[0022] Fig. 1 This is a schematic diagram of the hydraulic system of the present invention;

[0023] Fig. 2 This is a flowchart of the present invention;

[0024] In the diagram: 1. Main pump, 2. Pilot pump, 3. Pilot filter, 4. Pilot control valve, 5. Proportional valve YⅡ, 6. Proportional valve YⅢ, 7. Hydraulic cylinder, 8. Proportional valve YⅣ, 9. Inlet control valve, 10. Oil tank, 11. Directional valve, 12. Check valve CPⅡ, 13. Check valve CPⅠ, 14. Return control valve, 15. Pump-controlled proportional valve YⅠ. Detailed Implementation

[0025] like Figs. 1-2The throttling control based hydraulic excavator pressure stabilizing system shown in the figure comprises a main pump 1, the main pump 1 is connected with a pump control proportional valve YI 15, the main pump 1 is connected with a cylinder 7 through a reversing valve 11, the connecting end of the reversing valve 11 is connected with a proportional valve YII 5 and a proportional valve YIII 6 respectively, the oil inlet end of the reversing valve 11 is connected with a check valve CPII 12, a check valve CPI 13 and a return oil control valve 14, the check valve CP II 12 and the check valve CPI 13 are connected together with the main pump 1, the oil outlet end of the reversing valve 11 is connected with an oil inlet control valve 9 and the cylinder 7, one end of the oil inlet control valve 9 is connected with a proportional valve YIV 8, and the throttling control based hydraulic excavator pressure stabilizing system further comprises a pilot pump 2, the pilot pump 2 is connected with a pilot control valve 4 through a pilot filter 3.The main pump 1 is connected together with the oil inlet control valve 9 through a bypass path of the reversing valve 11.The other end of the oil inlet control valve 9 is connected with an oil tank 10.The throttling control based hydraulic excavator pressure stabilizing system of the present application comprises a main pump, a reversing valve, a cylinder, an oil inlet control valve, an oil tank, a check valve CP II, a check valve CPI, a return oil control valve, a pilot pump, a pilot filter, a pilot control valve, a proportional valve YII, a proportional valve YIII, a proportional valve YIV, a pump control proportional valve YI, an electric control handle, a controller, an engine and the like, the system is provided with an oil inlet control valve, and the preheating of hydraulic oil can be realized through the throttling effect of the oil inlet control valve, so that the function of reducing the pressure pulsation of the system is achieved; when the hydraulic excavator is started, the reversing valve is provided with an oil inlet bypass return oil, and the starting pressure stabilization is realized through the bypass throttling effect; when the hydraulic excavator is started, the return oil control valve is provided, the stable return oil pressure effect is realized through the setting of the return oil back pressure; when the hydraulic excavator is stopped, the reversing valve is provided with an oil inlet bypass return oil, and the stopping pressure stabilization is realized through the bypass throttling effect; when the hydraulic excavator is executing the working process, the pressure fluctuation caused by the external load and the execution speed change can be reduced through the oil inlet bypass return oil.

[0026] As shown in the throttling control based hydraulic excavator pressure stabilizing system, Figs. 1-2 The pump control proportional valve YI 15, the proportional valve YII 5, the proportional valve YIII 6, the return oil control valve 14, the oil inlet control valve 9, the proportional valve YIV 8 and the pilot control valve 4 are connected with a controller. The throttling control based hydraulic excavator pressure stabilizing system of the present application can control various valve bodies through the controller according to different situations, so that the smooth operation of the hydraulic excavator during starting, stopping and working is realized.

[0027] As shown in the throttling control based hydraulic excavator pressure stabilizing system, Figs. 1-2 The reversing valve 11 is a three-position six-way pilot reversing valve. In the three working positions of the reversing valve of the present application, one path is communicated with the oil inlet control valve, the hydraulic oil enters the oil inlet control valve through the bypass oil path, different effects are realized according to the different working positions of the oil inlet control valve, and finally the smooth operation of the whole system is realized.

[0028] The method for using the hydraulic excavator pressure stabilization system based on throttle control comprises the following steps:

[0029] S1, the engine is started, the main pump 1 is in working condition, the main pressure oil reaches the reversing valve 11 through the check valve CPI 13, and reaches the oil tank 10 through the central bypass oil way of the reversing valve 11;

[0030] S2, if the hydraulic oil temperature is lower than the set value at this time, the controller controls the oil inlet control valve 9 to make the left throttle oil level in working oil level, until the hydraulic oil temperature reaches the set temperature, the controller controls the oil inlet control valve 9 to make the right passage enter the working oil level;

[0031] S3, the pilot oil provided by the pilot pump 2 reaches the pilot control valve 4 through the pilot filter 3, after the hydraulic oil temperature reaches the set temperature, the pilot control valve 4 is powered on, the pilot oil enters the inlet ports of the proportional valve YII 5 and the proportional valve YIII 6 at both ends of the reversing valve 11 through the working oil level of the pilot control valve 4;

[0032] S4, the electric control handle is actuated, the controller controls the proportional valve YII 5 or the proportional valve YIII 6 to be powered on, the pilot control oil enters the left end or the right end of the reversing valve 11 through the proportional valve YII 5 or the proportional valve YIII 6, and the reversing valve 11 is pushed into the working oil level, at this time, the main pressure oil enters the large cavity or the small cavity of the oil cylinder 7 through the main pump 1, the check valve CPI 12 and the left cd oil way of the reversing valve 11, and the oil cylinder is extended or retracted;

[0033] S5, if the oil cylinder 7 is extended at this time, the hydraulic oil in the small cavity of the oil cylinder 7 returns to the oil tank through the fe oil way of the reversing valve 11 and the throttle oil way of the oil return control valve 14, and the oil cylinder action is completed;

[0034] S6, at the moment when the hydraulic excavator is started to work, the controller controls the oil inlet control valve 9 to make the throttle oil level in working oil level, at this time, the main pressure oil provided by the main pump 1 returns to the oil tank through the check valve CPI 13, the central bypass ab or a1b1 of the reversing valve 11 and the throttle oil level of the oil inlet control valve 9, so as to reduce the hydraulic starting impact caused by the main pressure oil; at the same time, the controller controls the oil return control valve 14 to make the throttle oil level in working oil level, so as to increase the back pressure of the oil return and reduce the oil return impact;

[0035] S7, after the starting is completed, the controller controls the oil inlet control valve 9 to make the middle cut-off position in working oil level, and the controller controls the oil return control valve 14 to make the passage in working oil level, so that the main pressure oil provided by the main pump 1 is completely supplied to the oil cylinder 7.

[0036] When the hydraulic excavator works in harsh conditions, the controller controls the oil inlet control valve 9 to make the throttle oil level in working oil level, and the oil inlet bypass of the reversing valve 11 returns to oil, so as to reduce the pressure fluctuation caused by the external load and the change of execution speed.

[0037] When the electric control handle is returned to the neutral position, the hydraulic excavator will stop working, the controller controls the pump control current of the pump control proportional valve Y115 to the set value, reduces the output flow of the main pump 1, controls the throttle oil level of the oil inlet control valve 9 to the working oil level, reduces the control current of the proportional valve Y15 or the proportional valve Y16, and makes the output pilot control pressure reduce, and the reversing valve 11 returns to the neutral position; The main pressure oil provided by the main pump 1 passes through the ab or a1b1 oil way of the reversing valve 11 to the central bypass oil way, and returns to the tank through the throttle oil level of the oil inlet control valve 9, thereby reducing the impact of the excavator stopping.

[0038] When the hydraulic excavator starts, the hydraulic oil is preheated to reach the set temperature, and then the main pressure oil passes through the valve core bypass return to flow through the throttle buffer of the oil inlet control valve, thereby reducing the hydraulic starting impact, at the same time, the controller controls the return control valve to be energized, so that the throttle oil level is at the working oil level, the return back pressure is increased, and the return impact is reduced. When the hydraulic excavator works in harsh conditions, the pressure fluctuation caused by the change of external load and execution speed can be reduced by bypassing the oil inlet and returning the oil. When the hydraulic excavator needs to stop, the controller reduces the pump control proportional valve current to the set value, reduces the flow output of the main pump, and at the same time makes the main pressure oil provided by the main pump to return to the tank after bypassing the valve core, flow through the throttle position of the oil inlet control valve, realize bypass throttle pressure stabilization, thereby reduce the impact of the excavator stopping, and finally realize the smooth running of the hydraulic excavator during starting, stopping and working.

Claims

1. A method of using a hydraulic excavator pressure stabilization system based on throttle control, characterized by: The system comprises a main pump (1) connected with a pump control proportional valve YI (15), the main pump (1) is connected with a cylinder (7) through a reversing valve (11), the connecting end of the reversing valve (11) is connected with a proportional valve YII (5) and a proportional valve YIII (6) respectively, the oil inlet end of the reversing valve (11) is connected with a check valve CPII (12), a check valve CPI (13) and a return oil control valve (14), the check valve CPII (12) and the check valve CPI (13) are connected together with the main pump (1), the oil outlet end of the reversing valve (11) is connected with an oil inlet control valve (9) and the cylinder (7), one end of the oil inlet control valve (9) is connected with a proportional valve YIV (8), and the system further comprises a pilot pump (2), the pilot pump (2) is connected with a pilot control valve (4) through a pilot filter (3); The pump control proportional valve YI (15), the proportional valve YII (5), the proportional valve YIII (6), the return oil control valve (14), the oil inlet control valve (9), the proportional valve YIV (8) and the pilot control valve (4) are connected with a controller; The system comprises the following steps: S1, the engine is started, the main pump (1) is in a working state, the main pressure oil reaches the reversing valve (11) through the check valve CPI (13), and reaches the oil inlet control valve (9) through the central bypass oil way of the reversing valve (11) and returns to an oil tank (10); S2, if the hydraulic oil temperature is lower than a set value at this time, the controller controls the oil inlet control valve (9) so that the throttling oil level is in a working oil level, when the hydraulic oil temperature reaches the set temperature, the controller controls the oil inlet control valve (9) so that the passage enters the working oil level; S3, the pilot oil provided by the pilot pump (2) reaches the pilot control valve (4) through the pilot filter (3), after the hydraulic oil temperature reaches the set temperature, the pilot control valve (4) is powered on, the pilot oil enters the oil inlet ports of the proportional valve YII (5) and the proportional valve YIII (6) at the two ends of the reversing valve (11) through the working oil level of the pilot control valve (4); S4, the electric control handle is actuated, the controller controls the proportional valve YII (5) or the proportional valve YIII (6) to be powered on, the pilot control oil enters the left end or the right end of the reversing valve (11) through the proportional valve YII (5) or the proportional valve YIII (6), and the reversing valve (11) is pushed into the working oil level, at this time, the main pressure oil enters the cylinder (7) through the main pump (1), the check valve CPII (12) and the oil way of the reversing valve (11), and the cylinder is extended or retracted; S5, if the cylinder (7) is extended at this time, the hydraulic oil in the small cavity of the cylinder (7) returns to the oil tank through the reversing valve (11) and the throttling oil way of the return oil control valve (14), and the cylinder action is completed; S6, at the moment when the hydraulic excavator is started, the controller controls the oil inlet control valve (9) so that the throttling oil level is in the working oil level, at this time, the main pressure oil provided by the main pump (1) returns to the oil tank through the check valve CPI (13), the central bypass of the reversing valve (11), the throttling oil level of the oil inlet control valve (9) and the oil tank, so as to reduce the hydraulic starting impact caused by the main pressure oil; meanwhile, the controller controls the return oil control valve (14) so that the throttling oil level is in the working oil level, the return oil back pressure is increased, and the return oil impact is reduced. ​ S7, after the completion of the start, the controller controls the oil inlet control valve (9) to make the middle cut-off position at the working oil level, the controller controls the oil return control valve (14) to make its passage at the working oil level, so that the main pressure oil provided by the main pump (1) is fully supplied to the oil cylinder (7); When the electric control handle is returned to the middle position, the hydraulic excavator will stop working, the controller controls the pump control current of the pump control proportional valve YⅠ(15) to the set value, reduces the output flow of the main pump (1), controls the throttle oil level of the oil inlet control valve (9) to the working oil level, reduces the control current of the proportional valve YⅡ(5) or the proportional valve YⅢ(6) to reduce the output pilot control pressure, and the reversing valve (11) is returned to the middle position; The main pressure oil provided by the main pump (1) is transferred to the central bypass oil circuit through the oil circuit of the reversing valve (11), and is returned to the tank through the throttle oil level of the oil inlet control valve (9), thereby reducing the impact of the excavator when stopping.

2. The method of using a throttle control based hydraulic excavator pressure maintenance system of claim 1, wherein: The reversing valve (11) is a three-position six-way pilot reversing valve.

3. The method of using a throttle control based hydraulic excavator pressure maintenance system of claim 2, wherein: The main pump (1) is connected with the oil inlet control valve (9) through the bypass of the reversing valve (11).

4. The method of using a throttle control based hydraulic excavator pressure maintenance system of claim 1, wherein: The other end of the oil inlet control valve (9) is connected with the oil tank (10).

5. The method of using a throttle control based hydraulic excavator pressure maintenance system of claim 1, wherein: When the hydraulic excavator works in harsh conditions, the controller controls the throttle oil level of the oil inlet control valve (9) to the working oil level, and the oil inlet bypass of the reversing valve (11) returns to oil, so as to reduce the pressure fluctuation caused by the change of its external load and execution speed.

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