WO2023092667A1

WO2023092667A1 - Hydraulic system with electro-proportional control multi-working-position valve, and control method thereof

Info

Publication number: WO2023092667A1
Application number: PCT/CN2021/136610
Authority: WO
Inventors: 孙辉; 崔骁; 肖刚; 黄飞; 徐艳翠
Original assignee: 江苏汇智高端工程机械创新中心有限公司
Priority date: 2021-11-25
Filing date: 2021-12-09
Publication date: 2023-06-01
Also published as: CN113819105A; CN113819105B

Abstract

A hydraulic system with an electro-proportional control multi-working-position valve, and a control method thereof. The system comprises: a first main pump (2), a second main pump (3), a pilot hydraulic-control joystick group, an arm cylinder (32), a main controller (42), an inward-swing pilot electro-proportional valve (7), and a valve core internally provided with a plurality of working positions. A signal output end of the main controller (42) is in joint control with the inward-swing pilot electro-proportional valve (7), and pilot ports at two external ends of the valve core are respectively in joint control with the pilot hydraulic-control joystick group and the inward-swing pilot electro-proportional valve (7) to regulate and control the working positions of the valve core. The main controller (42) in the hydraulic control system can determine the operating condition of an actuator mechanism, and can thus choose to run and control the hydraulic system in different operating conditions at a heavy-load working position or a light-load working position; and secondly, the area proportion of an oil return flow of an arm rod cavity passing through an oil return one-way valve (13) and a regeneration one-way valve (14) is controlled and regulated by means of the inward-swing pilot electro-proportional valve (7), so as to adapt to different operating conditions, thereby realizing fine regulation of a back pressure proportion of the actuator mechanism, and finally realizing back pressure control of the actuator mechanism under different loads.

Description

A hydraulic system with electric proportional control multi-position valve and its control method

technical field

The invention belongs to the technical field of hydraulic pressure, and in particular relates to a hydraulic system and a control method of an electric proportional control multi-position valve.

Background technique

In construction machinery, when the thrust direction of the hydraulic cylinder is opposite to the direction of the load (in most cases), the load is called a resistance load; As a result, the load on the hydraulic cylinder is in the same direction as the thrust of the hydraulic cylinder, and the load is called a tensile load at this time. Under the condition of tension load, the cavity on the oil supply side of the oil cylinder is very easy to cause the hydraulic components to suck due to insufficient flow, so the oil return back pressure is usually set higher under the tension load At low engine speed, the minimum flow rate obtained by the hydraulic actuator is not taken as a standard), in order to avoid damage to the hydraulic actuator caused by long-term suction. Setting a higher oil return back pressure of the actuator will cause the oil return back pressure to be large when the actuator is single-acting or the engine speed is high, and there will be energy loss, especially under the resistance load condition of the actuator, the oil return back pressure will be large Cause the machine energy consumption loss is big, work efficiency is low. Therefore, how to avoid cavitation under tension load and avoid extra back pressure energy consumption under resistance load is an urgent problem to be solved in engineering technology.

Contents of the invention

Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a hydraulic system and its control method for electric proportional control multi-position valves; the hydraulic control system can judge the working condition of the actuator, and then can Choose to operate and control the hydraulic system under different working conditions of work or light load to realize the back pressure control of the actuator under different loads, especially under the condition of tension load, so that the return oil flow enters the actuator through the parallel regenerative check valve The cavity can regenerate the flow, increase the oil inlet flow of the system, prevent the actuator from sucking air and improve the working efficiency; under the resistance conditions such as excavation of the actuator, the control valve automatically adjusts to the heavy-duty working position according to the load pressure, increasing the return of the actuator. Larger oil area, lower oil return back pressure, and lower host energy consumption.

Technical solution: The present invention provides a hydraulic system for electric proportional control of multi-position valves. When the stick is retracted, it includes:

The main pump set includes: a first main pump, a second main pump and a pilot oil pump; the first main pump, the second main pump and the pilot oil pump are all connected to the power output end of the engine;

The output ports of the first main pump and the second main pump are respectively connected to the fuel tank through corresponding bypass pipes and main throttle valve groups in sequence;

The pilot oil pump is also connected with the inward pilot electric proportional valve and the pilot hydraulic control handle group; the pilot hydraulic control handle group includes the outward swing pilot hydraulic control handle and the inward pilot hydraulic control handle;

The stick cylinder is divided into a stick cavity and a stick cavity according to the change of the oil supply part when the stick cylinder is swinging out and retracting;

The main controller, the signal input end of the main controller is jointly controlled with the first pressure sensor used to detect the internal pressure of the rodless cavity of the stick, and the second pressure sensor used to detect the pressure at the output port of the retracted pilot hydraulic control handle , the signal output terminal of the main controller is jointly controlled with the adduction pilot electro-proportional valve;

The spool has a plurality of working positions inside the spool, and the two ends of the spool have pilot ports, and the pilot ports are jointly controlled with the pilot hydraulic control handle group and the adduction pilot electric proportional valve respectively;

Wherein, the spool includes a first spool and a second spool, and the first spool and the second spool are provided with oil inlets connected to the main pump group through pipelines and connected to the arm through multiple sets of pipelines. There is an oil return port connected to the rod cavity; the oil return port on the first spool is also provided with a pipeline from the first spool to the second spool oil inlet;

The oil inlet of the first spool is connected to the output port of the first main pump through a bypass pipeline and communicates with the rodless cavity of the arm through multiple sets of connected pipelines to form an oil supply pipeline 1. The oil inlet of the second spool After the port is connected to the output port of the second main pump through a bypass pipe, it is connected with the rodless cavity of the stick through multiple sets of connected pipes to form oil supply pipe 2;

The rod cavity of the stick is connected to the first valve core and the second valve core in sequence through multiple sets of connected pipelines to form an oil return pipeline; the rod cavity of the stick is connected to the second valve core and the fuel tank in sequence through multiple sets of connected pipelines to form Oil return line 2.

In a further embodiment, the working position of the first spool includes: a retracting working position, an idle working position, and a swinging working position;

The working position of the second spool includes: an idle working position, a swing-out working position, a light-load working position, and a heavy-load working position.

In a further embodiment, the light-load working position and the heavy-load working position of the spool are respectively provided with an oil return check valve and a regeneration check valve.

In a further embodiment, when the arm retracts in the resistance load condition, the first valve core is adjusted to the retracted working position, the second valve core is adjusted to the heavy-duty working position, and the rodless chamber and the The pressure of the oil supply pipeline is greater than the pressure of the oil return pipeline; the oil return check valve connects the first spool and the second spool to the oil tank communication pipeline through the pipeline, so that the oil return pipeline 1 and the oil return pipeline 2 are connected in parallel ; The regenerative check valve connects the oil return line 1 connected in parallel to the second spool with the oil supply line 2, but since the pressure in the oil return line 1 is lower than the pressure in the oil supply line 2, the heavy The regenerative one-way valve on the loading position is closed; finally, the oil in the oil return line 1 passes through the oil return check valve and then merges with the oil return line 2 and finally reaches the oil tank;

When the stick retracts in the tension load working condition, the first spool is adjusted to the retracted working position, and the second spool is adjusted to the light-load working position.

The pressure in the rodless cavity of the stick and the oil supply pipeline connected with it is less than or equal to the pressure of the oil return line, and the oil in the rod cavity of the stick reaches the second valve core through the return line 2 and is blocked and passes through the return line. The oil in the oil pipeline 1 reaches the second spool and gathers, and the gathered oil is connected in parallel with the oil return check valve and the regeneration check valve on the light-load working position at the same time; a part of the oil passes through the regeneration check valve, The oil supply pipeline supplies oil to the rodless cavity of the arm in order to reuse the flow in the arm; the other part of the oil returns to the oil tank through the oil return check valve;

The stick actuator does not operate, the first spool and the second spool are at the idle position, and the main pump unit does not supply oil to the stick cylinder through the spool oil return check valve and regeneration check valve;

When the stick is swinging out, there is no tension load and resistance load condition, and then the first spool and the second spool are adjusted on the swing-out working position, and there is no oil return check valve and regeneration check valve on the swing-out working position , and then the oil supply flow from the main pump group through the spool only supplies oil to the stick cylinder through the swing-out working position, and the oil return flow of the stick cylinder also returns oil to the fuel tank through the swing-out working position.

In a further embodiment, the main controller judges the working condition through the collected pressure data of the first pressure sensor and the second pressure sensor, and controls the retraction pilot electro-proportional valve to select and control the work of the second spool according to the working condition bit.

In a further embodiment, when the first pressure sensor detects that the load pressure is lower than a predetermined value, it is judged that the stick cylinder is in a tension load condition; when the first pressure sensor detects that the load pressure is higher than a predetermined value, it is judged that the bucket The rod cylinder is in resistance load condition.

In a further embodiment, the pilot port includes: a first pilot port that swings out at one end of the first spool, a first pilot port that retracts at the other end of the first spool, and a first pilot port that is set at the second spool The outward swing second pilot port at one end, and the inward second pilot port set at the other end of the second spool; the inward second pilot port is connected with the inward pilot electric proportional valve, and the inward first pilot port The port is connected to the inward pilot hydraulic control handle, and the outward swing first pilot port and the outward swing second pilot port are connected to the outward swing pilot hydraulic control handle at the same time; The state control retracts the pilot electro-proportional valve to realize the adjustment of the working positions of the first spool and the second spool, and then the main controller controls the retracted pilot electro-proportional valve to adjust the area of the oil return check valve and the regeneration check valve The ratio allows the first spool and the second spool to switch to different working positions to meet the application of different working conditions.

In a further embodiment, the signal input terminal of the main controller is also jointly controlled with the first pilot electric control handle and the second pilot electric control handle, and the first pilot electric control handle and the second pilot electric control handle pass through The signal output terminal of the main controller is respectively connected with the inward first pilot proportional valve connected to the inward first pilot port, the joint control of the outward swing first pilot proportional valve of the first pilot port, and the joint control of the outward swing second pilot port. The outward swing second pilot proportional valve of the pilot port, and the joint control of the inward second pilot proportional valve of the inward second pilot port are jointly controlled.

In a further embodiment, when the stick actuator is not in operation; the spool is in the idle position, the main pump unit does not supply oil to the stick cylinder through the spool, and the overflow idle flow flows into the corresponding main throttle valve respectively. into the fuel tank.

In a further embodiment, the working steps in the retracted state of the stick include:

The main controller detects the pressure data of the first pressure sensor and the second pressure sensor in real time to judge the working condition;

When the user manipulates the pilot hydraulic control handle group, the main controller sends control instructions to the retracting pilot electric proportional valve according to the working condition data;

Under tension load conditions, adjust the first spool to the inward working position, and the second spool to the light-load working position; when the stick moves inward,

The oil supply flow in the first main pump and the second main pump respectively enters the rodless chamber of the stick through the first and second oil supply pipelines, and pushes the stick to move inwardly;

Part of the oil return flow from the rod chamber of the stick passes through the oil return check valve in the oil return line 1, enters the second valve core, and then supplies oil to the stickless cavity through the regeneration check valve; the other part of the flow passes through the oil return line 2 into the fuel tank;

Adjust the working position of the second spool to the heavy-duty position under resistance load conditions;

When the stick moves inward, the oil supply flow in the first main pump and the second main pump passes through the oil supply pipeline 1 and the oil supply pipeline 2 in turn, enters the rodless cavity of the stick, and pushes the stick to perform a retraction movement ;

Under this working condition, the internal oil pressure of the oil supply pipeline 2 at the connection point between the armless chamber and the regeneration check valve is greater than the oil pressure inside the oil return pipeline 1, so the regeneration check valve cannot receive the oil return pipeline 1 at this time. Oil return flow, oil return line 1 is connected to oil return line 2 in parallel and communicated with oil return line 2 through the oil return check valve, so that the oil return flow from the stick cavity through oil return line 1 can only be Through the oil return one-way valve to the second spool and the oil tank, the pipeline enters the oil tank, and finally the oil return flow of the oil return line 2 directly enters the oil tank through the second spool.

Beneficial effect: compared with the prior art, the present invention has the following advantages:

(1) In actual work, the main controller can judge the working condition of the actuator, and then can choose to operate and control the hydraulic system at the heavy-load working position or light-load working conditions. Under the condition of tension load, the oil return The flow regenerates the flow to the oil inlet chamber of the actuator through the parallel regenerative check valve, increasing the oil inlet flow of the system, preventing the actuator from sucking air and improving the working efficiency;

(2) Under resistance conditions, the control valve automatically adjusts to the heavy-duty working position according to the load pressure, increases the oil return area of the actuator, reduces the oil return back pressure, and reduces the energy consumption of the main engine;

(3) By retracting the pilot electro-proportional valve proportional control spool, and then adjusting the oil return flow of the rod cavity through the oil return check valve and the area ratio of the regeneration check valve to adapt to different working conditions and realize fine adjustment execution Mechanism back pressure ratio, and finally realize the actuator back pressure control under different loads.

Description of drawings

Fig. 1 is the working principle figure of multi-position spool of the present invention;

Fig. 2 is a structural diagram of the hydraulic system of the electric proportional control multi-position valve of the present invention under the idling state of the stick;

Fig. 3 is an implementation diagram of the hydraulic system of the electric proportional control multi-position valve of the present invention under the light-load working position under the state of the arm retracted;

Fig. 4 is an implementation diagram of the hydraulic system of the electric proportional control multi-position valve of the present invention under the heavy-duty working position under the retracted state of the stick;

Fig. 5 is an embodiment diagram of the pilot electric control handle used in the hydraulic system of the electric proportional control multi-position valve of the present invention;

Reference signs: 1. engine; 2. first main pump; 3. second main pump; 4. pilot oil pump; 5. outward swing pilot hydraulic control handle; 6. adduction pilot hydraulic control handle; 7. inward first Conductive proportional valve; 8. Second pressure sensor; 9. Inward second pilot port; 10. Outward swing second pilot port; 11. Second spool oil inlet; 12. Second spool and fuel tank communication pipe; 13. Oil return one-way valve; 14. Regeneration one-way valve; 15. Second spool bypass pipeline; 16. First spool oil return to second spool oil inlet pipeline; 17. Swing out first pilot port; 18, retracting the first pilot port; 19, the bypass pipe of the first spool; 20, the oil inlet of the first spool; 21, the connecting pipe between the first spool and the fuel tank; 22, the first spool and the bucket 23. The pipe connecting the second spool with the rod chamber of the stick; 24. The pipe connecting the first valve core with the rodless chamber of the stick; 25. The second valve core is connected with the rodless cavity of the stick Pipeline; 26, pipe with rodless chamber for stick; 27, pipe with rod chamber for stick; 28, main throttle valve one; 29, main throttle valve two; 30, fuel tank; 32, stick cylinder; 33, first Spool; 34. The first pressure sensor; 35. The first pilot proportional valve inward; 36. The first pilot proportional valve swinging out; 37. The second pilot proportional valve swinging out; 38. The second pilot proportional valve inward; 39. The first pilot electric control handle; 40. The second pilot electric control handle; 41. The second spool; 42. The main controller.

Detailed ways

In order to fully understand the technical content of the present invention, the technical solutions of the present invention will be further introduced and illustrated below in conjunction with specific examples, but not limited thereto.

In construction machinery, when the thrust direction of the hydraulic cylinder is opposite to the direction of the load (in most cases), the load is called a resistance load; As a result, the load on the hydraulic cylinder is in the same direction as the thrust of the hydraulic cylinder, and the load is called a tensile load at this time. Under the condition of tension load, the cavity on the oil supply side of the cylinder is very easy to cause the hydraulic components to suck due to insufficient flow. Therefore, under the condition of tension load, it is usually necessary to artificially set a high oil return back pressure to prevent the components Cavitation damage occurs. A high oil return back pressure will cause a large oil return back pressure of the hydraulic cylinder under common resistance load conditions, which will increase additional energy consumption and reduce work efficiency. At this time, back pressure loss is an unexpected consumption. How to avoid cavitation under tension load and avoid extra back pressure energy consumption under resistance load is an urgent problem to be solved in engineering technology.

Therefore, the technical solution of the present invention will be further described in conjunction with Fig. 1 to Fig. 4. A hydraulic system with electric proportional control multi-position valve includes: engine 1, first main pump 2, second main pump 3, pilot oil pump 4, external Pendulum pilot hydraulic control handle 5, adduction pilot hydraulic control handle 6, adduction pilot electric proportional valve 7, second pressure sensor 8, first spool 33, first pressure sensor 34, second spool 41, main throttle Valve one 28, main throttle valve two 29, fuel tank 30, stick oil cylinder 32, main controller 42.

Wherein, the first main pump 2 and the second main pump 3 are connected to the power output end of the engine 1; the power output by the engine 1 drives the first main pump 2 and the second main pump 3 to run; the first main pump 2, The output port of the second main pump 3 is connected with the main throttle group and the oil tank 30 through corresponding bypass pipelines in turn; main throttle valve two 29;

The pilot oil pump 4, the first main pump 2, and the second main pump 3 are driven by the engine 1; the pilot oil pump 4 is also connected with the inward pilot electric proportional valve 7 and the pilot hydraulic control handle set; the pilot hydraulic control handle set Including the swing-out pilot hydraulic control handle 5 and the retraction pilot hydraulic control handle 6;

The stick cylinder 32 is divided into a stick-rod cavity and a stick-free cavity according to the change of the oil supply position when the stick cylinder 32 is swung outward and retracted; when the stick cylinder 32 enters oil from the end without the piston rod, Oil is supplied to the rodless cavity of the stick, and the end with the piston rod is the end of the stick cavity, and the oil is returned to the cavity of the stick. The rod will protrude from the stick cylinder 32 to drive the stick to move; when the oil enters from the end with the piston rod, the oil enters the rod cavity, and the oil returns from the end without the piston rod, that is, the internal oil return in the rodless cavity , the pressure in the non-rod cavity of the stick is lower than the pressure inside the cavity of the stick, so that the piston rod retracts toward the non-rod cavity, and finally acts on the reverse movement of the stick.

The signal input end of the main controller 42 is jointly controlled with the first pressure sensor 34 used to detect the internal pressure of the rodless cavity of the stick, and the second pressure sensor 8 used to detect the pressure at the retracted pilot hydraulic control handle 6. The signal output terminal of the device 42 is jointly controlled with the adduction pilot electric proportional valve 7; furthermore, the pressure signal of the pilot hydraulic control handle and the load pressure signal of the stick cylinder 32 can be collected according to the first pressure sensor 34 and the second pressure sensor 8, and the stick pressure can be judged. The load condition of the oil cylinder 32 and the applicable operating position, and the calculated control command is output to the pilot retraction pilot electro-proportional valve 7 to perform proportional control on the valve core.

There are multiple working positions inside the spool, and there are pilot ports at both ends of the spool, and the pilot ports are jointly controlled with the pilot hydraulic control handle group and the adduction pilot electric proportional valve 7 respectively;

Wherein, the spool in the present invention in the retracted state of the stick includes a first spool 33 and a second spool 41, and the first spool 33 and the second spool 41 are provided with an oil inlet and a return port. Oil port; the oil return port is provided with a connecting pipe 21 with the first valve core and the fuel tank and a connecting pipe 12 between the second valve core and the fuel tank, and the rod cavity of the stick is connected to the first valve core 33, the second The second spool 41 forms the oil return pipeline 1;

The oil inlet port 20 of the first spool is connected to the output port of the first main pump 2 through a bypass pipe, and communicates with the rodless chamber of the arm through multiple sets of connected pipes to form an oil supply line 1. The second spool 41 After the oil inlet is connected to the output port of the second main pump 3 through a bypass pipeline, it communicates with the rodless chamber of the stick through multiple groups of connected pipelines to form oil supply pipeline 2; the bypass pipeline includes the first spool bypass pipeline 19 and The second spool bypasses the pipeline 15 .

The rod chamber of the stick is connected to the first valve core 33 and the second valve core 41 through pipelines to form an oil return pipeline; 30 forms oil return pipeline two.

In conjunction with accompanying drawings 1 to 4, the oil inlet and the oil return port include: the first spool oil inlet 20, the first spool oil return port, the second spool oil inlet 11, the second spool 41 oil return mouth;

Multiple sets of connected pipelines on the oil supply pipeline and oil return pipeline include: the oil return pipeline from the first spool to the oil inlet pipeline 16 of the second spool, the communication pipeline 21 between the first spool and the fuel tank, the first spool and the stick Rod chamber communication pipe 22, the second valve core and the stick rod chamber communication pipe 23, the first valve core and the stick rodless chamber communication pipe 24, the second valve core and the stick rodless chamber communication pipe 25, the second Two spool and fuel tank communication pipes 12, bucket rod-less cavity pipeline 26, and stick-rod cavity pipeline 27;

Further, the oil supply pipeline-oil supply flow is specifically that after the first main pump 2 inputs the oil supply flow to the first spool 33, the input oil enters the first spool and the bucket through the first spool oil inlet 20. After the rod-less cavity is connected to the pipeline 24, oil is supplied to the stick cylinder 32 through the stick-free cavity pipeline 26;

Further, the flow direction of the second oil supply flow of the oil supply pipeline is specifically that the output oil of the second main pump 3 enters the second valve core through the oil inlet 11 of the second valve core and enters the communication pipeline 25 between the second valve core and the armless cavity, and the armless cavity. Rod cavity pipeline 26 enters stick cylinder 32 to realize oil supply;

Further, the flow direction of the oil return line-the oil supply flow is specifically the part of the oil return flow inside the arm cylinder 32 from the arm rod chamber pipe 27 into the first valve core and the arm rod chamber communication pipe 22 to the first valve Spool 33, and then through the first spool oil return to the second spool oil inlet pipeline 16 into the second spool 41; through the second spool and the oil tank communication pipeline 12, finally flow to the oil tank 30 to return oil.

Further, the flow direction of the oil supply flow of the oil return line 2 is specifically that part of the oil return flow inside the stick cylinder 32 enters the second valve core and the stick rod cavity connecting pipe 23 from the stick rod chamber pipe 27 to the second valve. core 41 , this part of the oil return flow is communicated with the oil tank 30 through the second valve core and the oil tank communication pipe 12 , and finally flows to the oil tank 30 , thereby completing the oil return to the oil tank 30 .

The working positions of the first spool 33 include: inward working position, idling working position, and outward swing working position; the working position of the first spool 33 is adjusted by the pilot inward pilot electro-proportional valve 7 in the inward state of the stick. To the adduction work position.

The working positions of the second spool 41 include: an idle working position, a swing-out working position, a light-load working position, and a heavy-load working position.

The light-load working position and the heavy-duty working position of the second spool 41 are provided with an oil return check valve 13 and a regeneration check valve 14; The second spool 41 is adjusted to the heavy-duty working position for the inward working position. The pressure of the rodless chamber and the oil supply pipeline connected with it is greater than the pressure of the oil return pipeline; through the oil return check valve 13, the first The spool oil returns to the second spool oil inlet pipeline 16 and is connected to the second spool 41, so that the oil return line is connected in parallel to the oil inlet of the second spool 41 to realize the second communication with the oil return line, and the regeneration unit Directional valve 14 connects the oil return line 1 connected in parallel to the second spool with the oil supply line 2, but since the pressure in the oil return line 1 is lower than the pressure in the oil supply line 2, the heavy-duty working position The regeneration check valve 14 is closed; finally, the oil in the oil return line 1 passes through the oil return check valve 13 and then merges with the oil return line 2 and finally reaches the oil tank 30;

When the arm retracts in the tension load condition, the first spool 33 is adjusted to the inward working position, the second spool 41 is adjusted to the light-load working position, and the rodless cavity of the arm and the oil supply pipeline connected thereto The pressure is less than or equal to the pressure of the oil return line, and then the oil in the rod cavity of the stick reaches the second spool 41 through the oil return line 2 and is cut off, and the oil in the oil return line 1 reaches the second spool After 41, the converged oil is connected in parallel with the oil return check valve 13 and the regeneration check valve 14 on the light-load working position at the same time; then a part of the oil passes through the regeneration check valve 14, the oil supply pipeline The second spool communicates with the pipe 25 in the rodless chamber of the arm to supply oil to the arm cylinder 32 to realize reuse of the inward flow of the arm; another part of the oil is returned to the oil tank 30 through the oil return check valve 13 .

The stick actuator is not in operation, the first spool 33 and the second spool 41 are both at the idle position, and the main pump unit does not supply oil to the stick cylinder 32 through the spool oil return check valve 13 and regeneration check valve 14. Oil;

When the arm is swinging out, there is no tension load and resistance load condition, and then the first valve core 33 and the second valve core 41 are adjusted on the outward swing working position, and there is no oil return check valve 13 and regeneration valve on the outward swing working position. The one-way valve 14, and then the oil supply flow from the main pump group through the spool only supplies oil to the stick cylinder 32 through the swing-out working position, and the oil return flow of the stick cylinder 32 also only passes through the swing-out working position to the oil tank 30 times. Oil.

Further, when the arm swings outward, the flow direction of the oil supply pipeline 1 is that the flow through the first main pump 2 passes through the first valve core oil inlet 20, the connecting pipe 24 between the first valve core and the armless cavity, The rodless chamber pipe 26 realizes oil supply to the rod cylinder 32;

The flow direction of the oil supply pipeline 2 is the second main pump 3, the second valve core oil inlet 11, the second valve core and the armless chamber connecting pipe 25, the armless chamber pipe 26 to realize the supply of the arm cylinder 32 Oil;

The flow direction of the oil return line 1 is to enter the fuel tank 30 through the stick cylinder 32, the stick rod cavity pipe 27, the first valve core and the stick rod cavity connecting tube 22, and the first valve core and the fuel tank connecting tube 21 to realize the oil return line. road once oil;

The flow direction of the oil return line 2 is to enter the fuel tank 30 through the stick cylinder 32, the stick rod cavity pipe 27, the second valve core and the stick rod cavity connecting pipe 23, and the second valve core and the fuel tank connecting pipe 12 to realize the oil return pipe road secondary oil;

At the same time, the regenerative check valve 14 connects the oil return line 1 connected in parallel to the second spool 41 with the oil supply line 2, and then the oil return flow of the rod chamber of the stick passes through the first valve on the oil return line 1 The spool 33 and the second spool 41 return oil, and part of the oil return flow enters the second spool 41 through the raw check valve to realize the reuse of the inward flow of the stick.

The main controller 42 judges the working condition through the collected pressure data of the first pressure sensor 34 and the second pressure sensor 8,

When the main controller 42 collects the load pressure signal value converted by the first pressure sensor 34 and is lower than the predetermined value, it is judged that the stick cylinder 32 is in the tension load condition; when the main controller 42 collects the load pressure signal converted by the first pressure sensor 34 When the value is higher than the predetermined value, it is judged that the arm cylinder 32 is in the resistance load condition.

The pilot ports include: the outward swing first pilot port 17 set at one end of the first spool 33 , the inward first pilot port 18 set at the other end of the first spool 33 , the outward swing set at one end of the second spool 41 The second pilot port 10, and the retracting second pilot port 9 arranged at the other end of the second valve core 41; the retracting second pilot port 9 is connected with the retracting and retracting pilot electric proportional valve 7, and the retracting The first pilot port 18 is connected to the inward pilot liquid control handle 6, and the outward swing first pilot port 17 and the outward swing second pilot port 10 are respectively connected to the outward swing pilot liquid control handle 5; At the same time, the main controller controls the adduction pilot electro-proportional valve 7 according to the working conditions to adjust the working positions of the first spool 33 and the second spool 41, and then the main controller 42 controls the adduction pilot electro-proportional valve 7 The area ratio of the oil return check valve 13 and the regeneration check valve 14 is adjusted so that the first spool 33 and the second spool 41 switch to different working positions to meet the application of different working conditions.

Further combined with the embodiment shown in Fig. 5, the present invention proposes to use the pilot electric control handle instead of the pilot hydraulic control handle, which specifically includes: retracting the first pilot proportional valve 35, swinging out the first pilot proportional valve 36, and swinging out the second pilot Proportional valve 37 , retracting second pilot proportional valve 38 , first pilot electric control handle 39 , second pilot electric control handle 40 .

Wherein, the signal input terminal of the main controller 42 is jointly controlled with the first pilot electric control handle 39 and the second pilot electric control handle 40, and the first pilot electric control handle 39 and the second pilot electric control handle 40 are controlled by the main controller. The signal output ends of the signals are respectively connected to the inward first pilot proportional valve 35 at the inward first pilot port 18, the outward swing first pilot proportional valve 36 of the joint control outward swing first pilot port 17, and the joint control outward swing first pilot proportional valve 36. The outward swing second pilot proportional valve 37 of the second pilot port 10, and the joint control of the inward second pilot proportional valve 38 of the inward second pilot port 9;

The user's hand operates the electric control handle, and the electric control handle sends the control signal to the main controller 42. At the same time, the first pressure sensor 34 collects the output pressure of the rodless cavity of the stick and enters the main controller 42. The signal and the load pressure of the arm are used to calculate the control signal. When the arm is retracted, the main controller sends the control signal to the first retracted pilot proportional valve 35 and the retracted second pilot proportional valve 38, and the retracted second pilot proportional valve 38. A pilot proportional valve 35 outputs the control pressure to the first spool 33 and retracts the first pilot port 18, controls the first spool 33 of the arm to work at the retracted position, and retracts the second pilot proportional valve 38 to output the control pressure to the bucket The second spool 41 of the rod retracts the second pilot port 9 to control the second spool 41 of the arm to work at the light-load working position or the heavy-load working position; when the arm is swinging outward, the main controller Send the control signal to the swing-out first pilot proportional valve 36 and the swing-out second pilot proportional valve 37, and the swing-out first pilot proportional valve 36 outputs the control pressure to the arm first spool 33 and swing-out first pilot port 17 , control the first spool 33 of the stick to work at the swing-out position, the second swing-out pilot proportional valve 37 outputs control pressure to the second pilot port 10 of the second swing-out spool 41 of the stick, and control the second valve of the stick Core 41 works in the swing-out working position.

The working principle in the retracted state of the stick:

The main controller 42 detects the pressure data of the first pressure sensor 34 and the second pressure sensor 8 in real time to judge the working condition; The valve sends control commands;

Under tension load conditions, adjust the first spool 33 to be in the inward working position, and the second spool 41 to be in the light-load working position; when the stick moves inward,

The oil supply flow in the first main pump 2 and the second main pump 3 enters the rodless chamber of the stick cylinder 32 through the oil supply pipeline 1 and the fuel supply pipeline 2 respectively, and pushes the stick to perform retraction movement ;

Stick oil cylinder 32 The oil return part of the stick cavity of the stick passes through the oil return check valve 13 in the oil return line 1, enters the second valve core 41, and then passes through the regeneration check valve 14 to the oil supply line 2 and finally to the bucket Oil is supplied to the rodless cavity; another part of the flow enters the oil tank 30 through the oil return line 2;

When the arm moves inwardly, the oil supply flow in the first main pump 2 and the second main pump 3 passes through the oil supply pipeline 1 and the oil supply pipeline 2 in sequence, and enters the armless cavity of the arm cylinder 32, pushing The stick moves inward;

Under this working condition, the internal oil pressure of oil supply line 2 at the point where the armless cavity is connected with regenerative check valve 14 is greater than the oil pressure inside oil return line 1, so regeneration check valve 14 cannot receive the return oil line at this time. For the oil return flow in the first, the oil return line 1 is connected to the oil return line 2 in parallel and communicates with the oil return line 2 through the oil return check valve 13, so that the oil return flow from the stick cavity through the oil return line 1 , can only enter the oil tank 30 through the oil return check valve 13 to the second spool and the oil tank communication pipe 12; the oil return flow of the oil return line 2 directly enters the oil tank 30 through the second spool 41 and the second spool and the oil tank communication pipe .

The main controller 42 of the present invention can judge a variety of different working conditions of the actuator when the stick is retracted, and then can choose to operate and control the hydraulic system in different working conditions of heavy-load work position or light-load work. Next, the oil return flow is regenerated to the oil inlet chamber of the actuator through the parallel regenerative check valve 14, increasing the oil inlet flow of the system, preventing the actuator from sucking air and improving the working efficiency at the same time;

Under the condition of resistance, the control valve automatically adjusts to the heavy-duty working position according to the load pressure, increases the oil return area of the actuator, reduces the back pressure of the oil return, and reduces the energy consumption of the main engine.

According to the instructions issued by the main controller 42 according to the working conditions, the proportion control valve core of the adduction pilot electro-proportional valve 7 is controlled, and then the area ratio of the oil return flow of the stick cavity through the oil return check valve 13 and the regeneration check valve 14 is adjusted. In order to adapt to different working conditions, finely adjust the back pressure ratio of the actuator, and finally realize the back pressure control of the actuator under different loads.

The present invention has been described above by way of illustration of the accompanying drawings. Those skilled in the art should understand that the present disclosure is not limited to the embodiments described above, and various changes and changes can be made without departing from the scope of the present invention. and replace.

Claims

A hydraulic system with electric proportional control multi-position valve, characterized in that, when the stick is retracted, it includes:

The main pump set includes: a first main pump, a second main pump and a pilot oil pump; the first main pump, the second main pump and the pilot oil pump are all connected to the power output end of the engine;

The output ports of the first main pump and the second main pump are respectively connected to the fuel tank through corresponding bypass pipes and main throttle valve groups; the pilot oil pump is also connected to the adduction pilot electric proportional valve and the pilot hydraulic control handle group ; The pilot hydraulic control handle group includes a swing-out pilot hydraulic control handle and an adduction pilot hydraulic control handle;

The stick cylinder is divided into the stick cavity and the stickless cavity according to the change of the oil supply part when the stick cylinder swings out and inward; the main controller, the signal input terminal of the main controller is used for detecting The first pressure sensor for the internal pressure of the rodless chamber of the stick is used for joint control with the second pressure sensor for detecting the pressure at the output port of the adduction pilot hydraulic control handle. The signal output end of the main controller is connected with the adduction pilot hydraulic proportional valve joint control;

The spool has a plurality of working positions inside the spool, and the two ends of the spool have pilot ports, and the pilot ports are jointly controlled with the pilot hydraulic control handle group and the adduction pilot electric proportional valve respectively;

Wherein, the spool includes a first spool and a second spool, and the first spool and the second spool are provided with oil inlets connected to the main pump group through pipelines and connected to the arm through multiple sets of pipelines. There is an oil return port connected to the rod cavity; the oil return port on the first spool is also provided with a pipeline from the first spool to the second spool oil inlet;

The oil inlet of the first spool is connected to the output port of the first main pump through a bypass pipeline and communicates with the rodless cavity of the arm through multiple sets of connected pipelines to form an oil supply pipeline 1. The oil inlet of the second spool After the port is connected to the output port of the second main pump through a bypass pipe, it is connected with the rodless cavity of the stick through multiple sets of connected pipes to form oil supply pipe 2;

The rod cavity of the stick is connected to the first valve core and the second valve core in sequence through multiple sets of connected pipelines to form an oil return pipeline; the rod cavity of the stick is connected to the second valve core and the fuel tank in sequence through multiple sets of connected pipelines to form Oil return line 2.
The hydraulic system of an electric proportional control multi-position valve according to claim 1, wherein the working positions of the first spool include: a retracting position, an idling position, and a swinging position;

The working position of the second spool includes: an idle working position, a swing-out working position, a light-load working position, and a heavy-load working position.
According to claim 1, the hydraulic system of electric proportional control multi-position valve is characterized in that, the light-load working position and the heavy-duty working position of the valve core are respectively provided with an oil return check valve and a regeneration check valve. to the valve.
According to claim 3, the electric proportional control hydraulic system of multi-position valve is characterized in that,

When the stick is in the resistance load condition, the first spool is adjusted to the inward working position, and the second spool is adjusted to the heavy-duty working position.

The pressure of the rodless cavity of the arm and the oil supply pipeline connected with it is greater than the pressure of the oil return pipeline; the oil return check valve connects the first valve core and the second valve core with the oil tank communication pipeline through pipelines, so that The oil return line 1 and the oil return line 2 are connected in parallel; the regeneration check valve connects the oil return line 1 connected in parallel to the second spool with the oil supply line 2, and finally the oil in the oil return line 1 passes through the oil return line After the check valve, it merges with the oil return line 2 and finally reaches the oil tank;

When the stick retracts in the tension load working condition, the first spool is adjusted to the retracted working position, and the second spool is adjusted to the light-load working position.

The pressure in the rodless cavity of the stick and the oil supply pipeline connected with it is less than or equal to the pressure of the oil return line, and the oil in the rod cavity of the stick reaches the second valve core through the return line 2 and is blocked and passes through the return line. The oil in the oil pipeline 1 reaches the second spool and gathers, and the gathered oil is connected in parallel with the oil return check valve and the regeneration check valve on the light-load working position at the same time; a part of the oil passes through the regeneration check valve, The oil supply pipeline supplies oil to the rodless cavity of the arm in order to reuse the flow in the arm; the other part of the oil returns to the oil tank through the oil return check valve;

The stick actuator does not operate, the first spool and the second spool are at the idle position, and the main pump unit does not supply oil to the stick cylinder through the spool oil return check valve and regeneration check valve;

When the stick is swinging out, there is no tension load and resistance load condition, and then the first spool and the second spool are adjusted on the swing-out working position, and there is no oil return check valve and regeneration check valve on the swing-out working position , and then the oil supply flow from the main pump group through the spool only supplies oil to the stick cylinder through the swing-out working position, and the oil return flow of the stick cylinder also returns oil to the fuel tank through the swing-out working position.
A hydraulic system with electric proportional control multi-position valve according to claim 1, characterized in that the main controller judges the working condition through the collected pressure data of the first pressure sensor and the second pressure sensor, and according to The working condition control retracts the pilot electro-proportional valve to select and control the working position of the second spool.
The hydraulic system of electric proportional control multi-position valve according to claim 5, characterized in that, when the first pressure sensor detects that the load pressure is lower than a predetermined value, it is judged that the stick cylinder is in a tension load condition; When the first pressure sensor detects that the load pressure is higher than a predetermined value, it is determined that the stick cylinder is in a resistance load condition.
According to claim 1, a hydraulic system with electric proportional control multi-position valve, characterized in that, said pilot port comprises: a first pilot port that swings out at one end of the first spool, and is set at the first valve The inward first pilot port at the other end of the core, the outward swing second pilot port set at one end of the second spool, and the inward second pilot port set at the other end of the second spool; the inward second pilot port The port is connected to the inward pilot electro-proportional valve, the inward first pilot port is connected to the inward pilot hydraulic control handle, and the outward swing first pilot port and outward swing second pilot port are simultaneously connected to the outward swing pilot hydraulic control handle. connected; then by manipulating the two pilot hydraulic control handles while the main controller controls the adduction pilot electric proportional valve according to the working conditions to realize the adjustment of the working positions of the first spool and the second spool, and then the main controller controls the adduction The pilot electric proportional valve adjusts the area ratio of the oil return check valve and the regeneration check valve.
According to claim 1, a hydraulic system with electric proportional control multi-position valve, characterized in that the signal input end of the main controller is also jointly controlled with the first pilot electric control handle and the second pilot electric control handle , the first pilot electric control handle and the second pilot electric control handle are respectively connected to the inward first pilot proportional valve connected to the inward first pilot port through the signal output end of the main controller, and jointly control the outward swing first The first pilot proportional valve that swings out at the pilot port, the second pilot proportional valve that swings out at the second pilot port is jointly controlled, and the second pilot proportional valve that swings in at the second pilot port is jointly controlled.
According to any one of claims 1 to 8, a hydraulic system with electric proportional control multi-position valve, characterized in that, when the stick actuator is not in operation; the valve core is at the idle position, and the main pump group does not pass through The spool supplies oil to the arm cylinder, and the idle flow of the two pumps respectively flows into the oil tank through the corresponding main throttle valve.
A control method for a hydraulic system of an electric proportional control multi-position valve, characterized in that the working steps in the retracted state of the stick include:

The main controller detects the pressure data of the first pressure sensor and the second pressure sensor in real time to judge the working condition;

When the user manipulates the pilot hydraulic control handle group, the main controller sends control instructions to the retracting pilot electric proportional valve according to the working condition data;

Under tension load conditions, adjust the first spool to the inward working position, and the second spool to the light-load working position; when the stick moves inward,

The oil supply flow in the first main pump and the second main pump respectively enters the rodless chamber of the stick through the first and second oil supply pipelines, and pushes the stick to move inwardly;

Part of the oil return flow from the rod chamber of the stick passes through the oil return check valve in the oil return line 1, enters the second valve core, and then supplies oil to the stickless cavity through the regeneration check valve; the other part of the flow passes through the oil return line 2 into the fuel tank;

Adjust the working position of the second spool to the heavy-duty position under resistance load conditions;

When the stick moves inward, the oil supply flow in the first main pump and the second main pump passes through the oil supply pipeline 1 and the oil supply pipeline 2 in turn, enters the rodless cavity of the stick, and pushes the stick to perform a retraction movement ;

Under this working condition, the internal oil pressure of the oil supply pipeline 2 at the connection point between the armless chamber and the regeneration check valve is greater than the oil pressure inside the oil return pipeline 1, so the regeneration check valve cannot receive the oil return pipeline 1 at this time. Oil return flow, oil return line 1 is connected to oil return line 2 in parallel and communicated with oil return line 2 through the oil return check valve, so that the oil return flow from the stick cavity through oil return line 1 can only be Through the oil return one-way valve to the second spool and the oil tank, the pipeline enters the oil tank, and finally the oil return flow of the oil return line 2 directly enters the oil tank through the second spool.