WO2023160245A1

WO2023160245A1 - Throttling control-based pressure stabilization system for hydraulic excavator, and use method therefor

Info

Publication number: WO2023160245A1
Application number: PCT/CN2022/144421
Authority: WO
Inventors: 李县军; 石立京; 汪允显; 史继江; 丁兰英; 夏友斌; 唐晓鹏; 刘邓; 王正华
Original assignee: 徐州徐工矿业机械有限公司
Priority date: 2022-02-28
Filing date: 2022-12-31
Publication date: 2023-08-31
Also published as: CN114754030A

Abstract

A throttling control-based pressure stabilization system for a hydraulic excavator and a use method therefor. A primary pump (1) is connected to a pump-controlled proportional valve YI (15); a connecting end of a selector valve (11) is connected to each of a proportional valve YII (5) and a proportional valve YIII (6); an oil intake end of the selector valve (11) is connected to a one-way valve CPII (12), a one-way valve CPI (13) and an oil return control valve (14), and an oil output end of the selector valve (11) is connected to an oil intake control valve (9) and an oil cylinder (7); one end of the oil intake control valve (9) is connected to a proportional valve YIV (8); and a pilot pump (2) is connected to a pilot control valve (4) by means of a pilot filter (3). When a hydraulic excavator is started, hydraulic oil is preheated at a set temperature, and then main pressure oil flows through the oil intake control valve (9) for throttling buffer after passing through a valve core bypass for oil return, such that the hydraulic starting impact is reduced; and at the same time, a controller controls the oil return control valve (14) to be powered on, such that a throttling oil level of the oil return control valve is located at an operating oil level, oil return back pressure is increased, and thus the oil return impact is reduced.

Description

Hydraulic Excavator Voltage Stabilization System and Application Method Based on Throttle Control

technical field

The invention relates to the technical field of engineering machinery, in particular to a hydraulic excavator voltage stabilizing system based on throttling control and a usage method.

Background technique

Hydraulic system is the core technology of hydraulic excavator. With the rapid and efficient demand in the hydraulic excavator market, excavator hydraulic technology is developing towards high speed, high pressure and large flow. The pulsation and pressure shock of the hydraulic system have become one of the important factors hindering the progress of hydraulic technology, and will also seriously affect People's health and the service life of machinery and equipment.

Existing traditional hydraulic excavators reduce system impact by matching the opening of the spool and the flow rate of the main pump when starting, stopping and working under harsh conditions. Due to the characteristics of high speed, high pressure and large flow of the hydraulic system itself, it is always It cannot effectively eliminate the pressure pulsation and shock when the hydraulic excavator starts, stops and under severe working conditions.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the deficiencies of the above-mentioned prior art, and provide a hydraulic excavator voltage stabilizing system based on throttling control with simple operation and good effect and its use method.

The present invention is realized by the following technical scheme: a hydraulic excavator pressure stabilizing system based on throttling control, including a main pump, the main pump is connected with a pump control proportional valve Y Ⅰ, and the main pump is connected with an oil cylinder through a reversing valve , the connection ends of the reversing valve are respectively connected with proportional valve Y Ⅱ and proportional valve Y Ⅲ, and the oil inlet end of the reversing valve is connected with check valve CP Ⅱ, check valve CP Ⅰ and oil return control valve, so The one-way valve CP II and the one-way valve CP I are connected with the main pump, the oil outlet end of the reversing valve is connected with the oil inlet control valve and the oil cylinder, and one end of the oil inlet control valve is connected with the proportional valve YIV , also includes a pilot pump, the pilot pump is connected with a pilot control valve through a pilot filter.

It further includes: the pump control proportional valve Y Ⅰ, proportional valve Y Ⅱ, proportional valve Y Ⅲ, oil return control valve, oil inlet control valve, proportional valve Y Ⅳ and pilot control valve are connected with a controller.

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

The main pump is connected with the oil inlet control valve through the bypass passage of the reversing valve.

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

The method for using a hydraulic excavator voltage stabilizing system based on throttling control includes the following steps:

S1. The engine starts and the main pump is in working condition. The main pressure oil reaches the reversing valve through the check valve CP Ⅰ, and then goes through the central bypass oil passage of the reversing valve to the oil inlet control valve and returns to the fuel tank;

S2. If the hydraulic oil temperature is lower than the set value at this time, the controller controls the oil inlet control valve so that the throttling oil level is at the working oil level. When the hydraulic oil temperature reaches the set temperature, the controller controls the oil inlet control valve. Make its passage into the working oil level;

S3. The pilot oil provided by the pilot pump reaches the pilot control valve through the pilot filter. After the hydraulic oil temperature reaches the set temperature, the pilot control valve is energized, and the pilot oil passes through the working oil level of the pilot control valve and enters the proportional valve at both ends of the reversing valve Y Ⅱ And the oil inlet port of proportional valve YⅢ;

S4. The electric control handle moves, the controller controls the proportional valve Y Ⅱ or proportional valve Y Ⅲ to be energized, the pilot control oil enters the left or right end of the reversing valve through the proportional valve Y Ⅱ or proportional valve Y Ⅲ, and pushes the reversing valve to enter the working oil level. At this time, the main pressure oil enters the oil cylinder through the main pump, the check valve CP II, and the reversing valve oil circuit, and the oil cylinder extends or retracts;

S5. If the oil cylinder is stretched out at this time, the hydraulic oil in the small chamber of the oil cylinder passes through the reversing valve and the oil return control valve to throttle the oil circuit and return to the oil tank to complete the action of the oil cylinder;

S6. At the moment when the hydraulic excavator is started, the controller controls the oil inlet control valve so that the throttling oil level is at the working oil level. The valve center bypasses the oil inlet control valve to throttle the oil level back to the oil tank to reduce the hydraulic start impact caused by the main pressure oil; at the same time, the controller controls the oil return control valve so that the throttle oil level is at the working oil level to increase the back pressure of the oil return , reduce oil return impact;

S7. After starting, the controller controls the oil inlet control valve so that the middle cut-off position is at the working oil level, and the controller controls the oil return control valve so that the passage is at the working oil level, so that the main pressure oil provided by the main pump is completely supplied to the actuator cylinder.

When the hydraulic excavator works under severe working conditions, the controller controls the oil inlet control valve so that the throttling oil level is at the working oil level, and the oil inlet of the reversing valve is bypassed to return the oil to reduce its external load and execute speed changes caused pressure fluctuations.

When the electric control handle returns to the neutral position and the hydraulic excavator will stop working, the controller controls the pump control current of the pump control proportional valve Y Ⅰ to the set value, reduces the output flow of the main pump, and controls the throttling of the oil inlet control valve at the same time When the oil level is at the working oil level, reduce the control current of proportional valve Y Ⅱ or proportional valve Y Ⅲ to reduce the output pilot control pressure, and the reversing valve returns to the neutral position; the main pressure oil provided by the main pump passes through the oil circuit of the reversing valve Bypass the oil circuit to the center, and throttle the oil level back to the oil tank through the oil inlet control valve, thereby reducing the shock of the excavator when it stops.

The present invention has the following advantages: the hydraulic excavator voltage stabilizing system based on throttling control and the use method of the present invention, when the hydraulic excavator is started, the hydraulic oil is preheated to reach the set temperature, and then the main pressure oil is passed through After the spool bypasses the oil return, it flows through the oil inlet control valve for throttling and buffering, thereby reducing the impact of hydraulic starting. Back pressure reduces oil return impact.

Description of drawings

Fig. 1 is a schematic diagram of a hydraulic system of the present invention;

Fig. 2 is a flow chart of the present invention;

In the figure: 1. Main pump, 2. Pilot pump, 3. Pilot filter, 4. Pilot control valve, 5. Proportional valve Y Ⅱ, 6. Proportional valve Y Ⅲ, 7. Oil cylinder, 8. Proportional valve Y Ⅳ, 9, Oil inlet control valve, 10, oil tank, 11, reversing valve, 12, one-way valve CP Ⅱ, 13, one-way valve CP Ⅰ, 14, oil return control valve, 15, pump control proportional valve Y Ⅰ.

Detailed ways

The hydraulic excavator voltage stabilizing system based on throttling control as shown in Figures 1 to 2 includes a main pump 1 connected to a pump control proportional valve Y I 15, and the main pump 1 passes through a reversing valve 11 Connected with the oil cylinder 7, the connecting ends of the reversing valve 11 are respectively connected with the proportional valve Y Ⅱ5 and the proportional valve Y Ⅲ6, and the oil inlet end of the reversing valve 11 is connected with the check valve CP Ⅱ12, the check valve CP Ⅰ13 and the The oil return control valve 14, the one-way valve CP II12 and the one-way valve CP I13 are connected with the main pump 1, the oil outlet end of the reversing valve 11 is connected with the oil inlet control valve 9 and the oil cylinder 7, the One end of the oil inlet control valve 9 is connected with a proportional valve YIV8 and also includes a pilot pump 2 connected with a pilot control valve 4 through a pilot filter 3 . The main pump 1 is connected with the oil inlet control valve 9 through the bypass passage of the reversing valve 11 . The other end of the oil inlet control valve 9 is connected with an oil tank 10 . The hydraulic excavator voltage stabilizing system based on throttling control of the present invention includes a main pump, a reversing valve, an oil cylinder, an oil inlet control valve, an oil tank, a one-way valve CP II, a one-way valve CP I, an oil return control valve, Pilot pump, pilot filter, pilot control valve, proportional valve Y Ⅱ, proportional valve Y Ⅲ, proportional valve Y Ⅳ, pump control proportional valve Y Ⅰ, electric control handle, controller, engine, etc. The system is equipped with an oil inlet control valve. Its throttling effect can realize the preheating of the hydraulic oil and reduce the pressure pulsation of the system; when the hydraulic excavator is started, the reversing valve is equipped with an oil inlet bypass to return the oil, and the starting pressure can be realized through the bypass throttling effect; the hydraulic pressure When the excavator is started, there is an oil return control valve, through which the oil return back pressure can be set to achieve stable oil return pressure; The throttling effect realizes the stop and stabilize the pressure; when the hydraulic excavator is in the process of performing work, the pressure fluctuation caused by the external load and the change of the execution speed can be reduced through the oil inlet bypass and oil return.

As shown in Figure 1 to Figure 2, the hydraulic excavator voltage stabilization system based on throttling control, the pump control proportional valve Y Ⅰ 15, proportional valve Y Ⅱ 5, proportional valve Y Ⅲ 6, oil return control valve 14, oil inlet control valve 9 , Proportional valve YⅣ8 and pilot control valve 4 are connected with a controller. The hydraulic excavator voltage stabilizing system based on throttling control of the present invention controls various valve bodies through the controller according to different situations, so as to realize the start and stop of the hydraulic excavator and the smooth operation during the working process.

As shown in Fig. 1 to Fig. 2, in the hydraulic excavator voltage stabilizing system based on throttling control, the reversing valve 11 is a three-position six-way pilot reversing valve. One of the three working positions of the reversing valve of the present invention communicates with the oil-inlet control valve, and the hydraulic oil enters the oil-inlet control valve through the bypass oil passage, and different effects are realized according to different working positions of the oil-inlet control valve. To achieve the smooth operation of the entire system.

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 CP Ⅰ13, and passes through the central bypass oil passage of the reversing valve 11 to the oil inlet control valve 9 and returns to the fuel tank 10;

S2. If the hydraulic oil temperature is lower than the set value at this time, the controller controls the oil inlet control valve 9 so that the left throttling oil level is at the working oil level, until the hydraulic oil temperature reaches the set temperature, the controller controls the oil inlet control Valve 9, so that its right channel 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 energized, and the pilot oil enters the reversing valve 11 through the working oil level of the pilot control valve 4. The oil inlet ports of proportional valve Y Ⅱ5 and proportional valve Y Ⅲ6 at both ends;

S4. The electric control handle moves, the controller controls the proportional valve YⅡ5 or the proportional valve YⅢ6 to energize, the pilot control oil enters the left end or the right end of the reversing valve 11 through the proportional valve YⅡ5 or the proportional valve YⅢ6, and pushes the reversing valve 11 to enter the working oil level At this time, the main pressure oil enters the large chamber or small chamber of the oil cylinder 7 through the main pump 1, the one-way valve CP Ⅱ 12, and the left position cd oil circuit of the reversing valve 11, and the oil cylinder extends or retracts;

S5. If the oil cylinder 7 is stretched out at this time, the hydraulic oil in the small chamber of the oil cylinder 7 passes through the reversing valve 11fe oil circuit, the oil return control valve 14 throttling the oil circuit and returns to the oil tank to complete the oil cylinder action;

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 at the working oil level. At this time, the main pressure oil provided by the main pump 1 passes through the check valve check valve CP Ⅰ13, The reversing valve 11 centrally bypasses ab or a1b1, and the oil inlet control valve 9 throttles the oil level back to the oil tank to reduce the hydraulic start impact caused by the main pressure oil; at the same time, the controller controls the oil return control valve 14 so that the throttle oil level is at Working oil level, increase oil return back pressure, reduce oil return impact;

S7. After the startup is completed, the controller controls the oil inlet control valve 9 so that the middle cut-off position is at the working oil level, and the controller controls the oil return control valve 14 so that the passage is at the working oil level, so that the main pressure oil provided by the main pump 1 is completely Supply to actuator cylinder 7.

When the hydraulic excavator is working under harsh conditions, the controller controls the oil inlet control valve 9 to make the throttling oil level at the working oil level, and the oil inlet of the reversing valve 11 bypasses the oil return to reduce its external load and perform Pressure fluctuations caused by speed changes.

When the electric control handle returns to the neutral position and the hydraulic excavator will stop working, the controller controls the pump control current of the pump control proportional valve Y Ⅰ15 to the set value, reduces the output flow of the main pump 1, and controls the oil inlet control valve 9 at the same time The throttling oil level is at the working oil level, reducing the control current of proportional valve YⅡ5 or proportional valve YⅢ6 to reduce the output pilot control pressure, and the reversing valve 11 returns to the neutral position; the main pressure oil provided by the main pump 1 passes through the reversing valve The ab or a1b1 oil circuit of 11 transitions to the central bypass oil circuit, and the oil level is throttled back to the oil tank through the oil inlet control valve 9, thereby reducing the impact of the excavator when it stops.

When the hydraulic excavator is started, the hydraulic oil is preheated to reach the set temperature, and then the main pressure oil is bypassed through the valve core to return the oil, and then flows through the oil inlet control valve for throttling and buffering, thereby reducing the impact of hydraulic starting. At the same time, the controller controls the energization of the oil return control valve so that the throttling oil level is at the working oil level, increasing the back pressure of the oil return and reducing the impact of the oil return. When the hydraulic excavator is working under harsh conditions, the pressure fluctuation caused by the external load and the change of the 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 current of the pump control proportional valve to the set value and reduces the flow output of the main pump. The throttling position of the oil control valve returns to the oil tank to achieve bypass throttling and voltage stabilization, thereby reducing the impact of the excavator when it stops, and finally realizing the smooth operation of the hydraulic excavator when it starts, stops, and works.

Claims

The voltage stabilizing system for hydraulic excavators based on throttling control is characterized in that it includes a main pump (1), the main pump (1) is connected with a pump control proportional valve YI (15), and the main pump (1) is replaced by The oil cylinder (7) is connected to the directional valve (11), and the connecting ends of the directional valve (11) are respectively connected with a proportional valve YII (5) and a proportional valve YIII (6), and the inlet of the directional valve (11) The oil end is connected with one-way valve CPII (12), one-way valve CPI (13) and oil return control valve (14), and the one-way valve CPII (12) and one-way valve CPI (13) are connected with the main pump (1 ) are connected together, the oil outlet end of the reversing valve (11) is connected with the oil inlet control valve (9) and the oil cylinder (7), and one end of the oil inlet control valve (9) is connected with the proportional valve YIV (8 ), also includes a pilot pump (2), and the pilot pump (2) is connected with a pilot control valve (4) through a pilot filter (3).
The hydraulic excavator voltage stabilizing system based on throttling control according to claim 1, characterized in that: the pump control proportional valve YI (15), proportional valve YII (5), proportional valve YIII (6), oil return The 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 pressure stabilizing system for hydraulic excavators based on throttling control according to claim 1, characterized in that: the reversing valve (11) is a three-position six-way pilot reversing valve.
The hydraulic excavator voltage stabilizing system based on throttling control according to claim 3, characterized in that: the main pump (1) is connected to the oil inlet control valve (9) through the bypass passage of the reversing valve (11) Together.
The pressure stabilizing system for a hydraulic excavator based on throttling control according to claim 1, characterized in that: the other end of the oil inlet control valve (9) is connected with an oil tank (10).
The method for using the hydraulic excavator voltage stabilizing system based on throttling control according to claim 1 is characterized in that: comprising the following steps:

S1. The engine starts, the main pump (1) is in working condition, the main pressure oil reaches the reversing valve (11) through the check valve CPⅠ (13), and then reaches the oil inlet through the central bypass oil passage of the reversing valve (11) The control valve (9) returns to the fuel tank (10);

S2. If the hydraulic oil temperature is lower than the set value at this time, the controller controls the oil inlet control valve (9) so that the throttling oil level is at the working oil level. When the hydraulic oil temperature reaches the set temperature, the controller controls the oil inlet Control the valve (9) so that its 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 energized, and the pilot oil passes through the pilot control valve ( 4) The working oil level enters the oil inlet port of proportional valve YⅡ(5) and proportional valve YⅢ(6) at both ends of reversing valve (11);

S4. The electric control handle moves, the controller controls the proportional valve YⅡ(5) or the proportional valve YⅢ(6) to be energized, and the pilot controls the oil to enter the reversing valve (11) through the proportional valve YⅡ(5) or the proportional valve YⅢ(6). Push the reversing valve (11) at the left end or the right end to enter the working oil level. At this time, the main pressure oil enters the oil cylinder (7) through the main pump (1), the check valve CPII (12), and the reversing valve (11). Cylinder extended or retracted;

S5. If the oil cylinder (7) is stretched out at this time, the hydraulic oil in the small cavity of the oil cylinder (7) passes through the reversing valve (11) and the oil return control valve (14) to throttle the oil circuit and return to the oil tank to complete the action of the oil cylinder;

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 at the working oil level. At this time, the main pressure oil provided by the main pump (1) passes through the one-way valve of the check valve. Valve CPⅠ (13), reversing valve (11), central bypass oil inlet control valve (9) throttling the oil level back to the oil 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 (14 ) make the throttling oil level at the working oil level, increase the back pressure of the oil return, and reduce the impact of the oil return;

S7. After the startup is completed, the controller controls the oil inlet control valve (9) so that the middle cut-off position is at the working oil level, and the controller controls the oil return control valve (14) so that the passage is at the working oil level, so that the main pump (1) The supplied main pressure oil is fully supplied to the actuator cylinder (7).
The method of using the hydraulic excavator voltage stabilizing system based on throttling control according to claim 6, characterized in that: when the hydraulic excavator is working under severe working conditions, the controller controls the oil inlet control valve (9) to make it The throttling oil level is at the working oil level, and the oil inlet of the reversing valve (11) bypasses the oil return to reduce the pressure fluctuation caused by its external load and execution speed change.
The method of using the hydraulic excavator voltage stabilizing system based on throttling control as claimed in claim 6, characterized in that: when the electric control handle returns to the neutral position and the hydraulic excavator stops working, the controller controls the pump control proportional valve YI The pump control current of (15) reaches the set value, reducing the output flow of the main pump (1), and at the same time controlling the throttling oil level of the oil inlet control valve (9) to be at the working oil level, reducing the proportional valve YII (5) or proportional The control current of valve YⅢ(6) reduces the output pilot control pressure, and the reversing valve (11) returns to the neutral position; the main pressure oil provided by the main pump (1) passes through the oil circuit of the reversing valve (11) to the central position. Bypass the oil circuit, and throttle the oil level back to the oil tank through the oil inlet control valve (9), thereby reducing the impact of the excavator when it stops.