CN109458370B - Hydraulic system based on negative flow control system - Google Patents
Hydraulic system based on negative flow control system Download PDFInfo
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- CN109458370B CN109458370B CN201811482507.XA CN201811482507A CN109458370B CN 109458370 B CN109458370 B CN 109458370B CN 201811482507 A CN201811482507 A CN 201811482507A CN 109458370 B CN109458370 B CN 109458370B
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- 239000003921 oil Substances 0.000 description 113
- 239000007788 liquid Substances 0.000 description 8
- 239000010720 hydraulic oil Substances 0.000 description 4
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B13/00—Details of servomotor systems ; Valves for servomotor systems
- F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
Abstract
The invention provides a hydraulic system based on a negative flow control system, which is additionally provided with a flow regulation and control pressure reducing valve (9), a second selection valve and a first selection valve on the basis of the existing negative flow control system, when a newly-added functional valve group is used, the original functional valve group is closed through the second selection valve and the first selection valve, a flow control valve (5) is communicated with the flow regulation and control pressure reducing valve, and the flow of the newly-added functional valve group is regulated and controlled by the flow regulation and control pressure reducing valve. The invention can realize that a newly added function valve group is arranged on the basis of the existing negative flow control system without adding a new pump, and the valve group is connected to the original flow control valve through the flow regulation and control pressure reducing valve to control the flow of the main pump, so that the newly added actuating mechanism obtains the required flow, the requirement of the action added by the newly added actuating mechanism on the flow diversity of the system can be realized, the operation is simple and convenient, the feasibility is strong, and the application range of the original negative flow control system is effectively expanded.
Description
Technical Field
The invention relates to the field of hydraulic systems of engineering machinery, in particular to a hydraulic system based on a negative flow control system.
Background
At present, the negative flow control system is widely applied to the field of engineering machinery, and is good in control due to stable service performance, and particularly on an excavator, most of the excavators of the brands adopt the negative flow control system. Because the excavator has large market demand and correspondingly large production batch, the hydraulic components for the excavator also have large production batch, and the quality and the production cost of batch production can be well controlled, so the hydraulic oil pump, the hydraulic valve and the negative flow control system for the excavator have high cost performance, and therefore, in a hydraulic system of other engineering machines, particularly piling machinery products, a plurality of cases of using the negative flow control system of the excavator exist.
The structure of a typical conventional negative flow control system is shown in fig. 1, the negative flow control system includes a feedback valve 1, a main pump 3, a pilot pump 4, a flow control valve 5, and a plurality of groups of function valves 16, each group of function valves includes a pilot-controlled directional valve 161 and a proportional pressure reducing valve 162 corresponding to the pilot-controlled directional valve, the pilot-controlled directional valves of the groups of function valves are connected in parallel and then communicated with an oil tank through the feedback valve 1, hydraulic oil from the main pump flows to an inlet of the feedback valve 1 through the groups of function valves, a pressure difference P is generated between the inlet of the feedback valve 1 and the oil tank, the pressure difference acts on the flow control valve 5, when each group of function valves is not actuated, the pressure difference is the largest, the pressure acting on the flow control valve 5 is the largest, at this time, the flow control valve 5 pushes a swash plate of the main pump to the smallest, the flow rate of the main pump is the smallest, when a group, corresponding pilot valve and liquid accuse switching-over valve all have the action), above-mentioned pressure differential can diminish, and main pump sloping cam plate angle can grow under the effect of the power of flow control valve 5's spring, and the main pump flow can grow thereupon, and when all valves all had the action, the flow of pump was the biggest.
Because the number of valve banks in the negative flow control system is generally fixed, if the negative flow control system used by the excavator has only 7 groups of functional valves, all groups of functional valves are integrally processed together, and no spare functional valves are reserved, if the number of actions of other engineering machinery or piling products exceeds the number provided by the negative flow control system of the excavator, one functional valve needs to be correspondingly added for each action. Because the original function valve and the main pump flow are mutually matched, each group of function valves controls one set of actuating mechanism, each set of actuating mechanism completes one action, and because the functions and actions to be realized by each actuating mechanism are different, the newly added function valve can not obtain the required flow only after the outlet of the main pump is connected with the newly added function valve.
Therefore, if other engineering machines or piling machines need to add new actions, in addition to adding corresponding function valves, a new pump needs to be added to provide the required flow for the newly added actuator, which results in increased cost, and the installation space is also limited to a certain extent. Therefore, there is a need in the art for a solution to this problem.
Disclosure of Invention
The invention aims to provide a hydraulic system based on a negative flow control system to solve the problems in the background art.
A hydraulic system based on a negative flow control system comprises a feedback valve 1, a main pump 3, a pilot pump 4, a flow control valve 5, a second selection valve 8, a flow control pressure reducing valve 9 and a plurality of groups of newly-added function valves 6, wherein each group of newly-added function valves is connected with an original function valve in parallel, and each group of newly-added function valves comprises a comparison valve 63, a newly-added hydraulic control reversing valve 61 and a newly-added proportional pressure reducing valve 62 for controlling the newly-added hydraulic control reversing valve.
The new proportion relief pressure valve is provided with a signal oil port A and a signal oil port B, the signal oil port A and the signal oil port B are respectively connected to two hydraulic control signal ports of the new hydraulic control reversing valve, the comparison valve 63 is further connected between the signal oil port A and the signal oil port B, two oil inlets of the comparison valve are respectively connected with the signal oil port A and the signal oil port B, the flow regulation and control relief pressure valve is provided with an outer control port K, an oil outlet of the comparison valve is connected with the outer control port K of the flow regulation and control relief pressure valve, and pressure oil flowing out of an oil outlet of the comparison valve is pressure oil of one signal oil port with large pressure in the signal oil port A and the.
An oil inlet J of the flow regulation and control pressure reducing valve 9 is connected to the outlet of the pilot pump, and the internal structure of the flow regulation and control pressure reducing valve is set as follows: the maximum oil pressure and/or the minimum oil pressure of the oil outlet C can be adjusted (the maximum oil pressure and the minimum oil pressure of the oil outlet C can be adjusted according to the flow required by a newly-added executing mechanism), the larger the oil inlet pressure of the external control port K is, the smaller the oil outlet pressure of the oil outlet C is, the oil outlet C of the flow regulation and control pressure reducing valve is connected to the second selector valve, the inlet of the feedback valve 1 is communicated with a second selection valve, the outlet of the second selection valve is connected to the flow control valve 5, the second selection valve is used for switching the flow control valve between two states of being communicated with the feedback valve or the flow regulating and reducing valve, thereby leading the main pump to carry out flow regulation and control by the original feedback valve 1 when driving the original actuating mechanism, and to carry out flow regulation and control by the flow regulation and control pressure reducing valve when driving the newly added actuating mechanism, the functions of the original function valve and the original actuating mechanism are not influenced, and meanwhile, the newly added actuating mechanism can obtain the required flow during working.
Furthermore, the hydraulic system based on the negative flow control system further comprises a switch valve 2, the switch valve 2 is connected to the tail end of the oil path of each original liquid control reversing valve after being connected in parallel and is located at the upstream of the feedback valve, the tail end of each group of original liquid control reversing valves after being connected in parallel is sequentially communicated with the oil tank through the switch valve and the feedback valve, hydraulic oil coming out of the main pump passes through each group of original function valves, then flows to the inlet of the feedback valve 1, and the switch valve 2 is used for closing the oil path between each original liquid control reversing valve and the feedback valve when the flow control pressure reducing valve is communicated with the flow control valve.
Furthermore, the hydraulic system based on the negative flow control system further comprises a first selection valve 7, an oil outlet of the comparison valve is divided into two paths, one path is connected with an external control port K of the flow regulation and control pressure reducing valve, the other path is connected with an oil inlet of the first selection valve, the first switching valve is a hydraulic control reversing valve, the oil outlet of the first selection valve is connected with a pilot control oil port of the first switching valve, and the first selection valve is used for enabling pilot oil of the first switching valve to be communicated to obtain reversing power when the first switching valve needs to close an oil path between each original hydraulic control reversing valve and the feedback valve.
Preferably, the comparison valve is a shuttle valve, and the first selection valve and the second selection valve are both solenoid directional valves.
Further, the flow rate regulation pressure reducing valve 9 comprises a valve body 90, a valve core 92, a spring 93 and an adjusting screw 94, a valve cavity 91 is arranged in the valve body, an oil inlet J, an oil outlet C and an external control port K are communicated with the valve cavity, a throttling structure 97 is arranged between the inner wall of the valve cavity at the oil outlet C and the valve core, the valve core is arranged in the valve cavity, a screw hole 95 communicated with the valve cavity is arranged on the valve body, an oil drain port 96 communicated with an oil tank is also arranged on the valve body, the adjusting screw is screwed in the screw hole, the spring is abutted between the adjusting screw and the valve core, the elastic direction of the spring is arranged along the direction pointing to the external control port K, the oil inlet J and the oil outlet C are in a normally communicated state, when the pressure oil of the external control port K overcomes the elastic force of the spring 93 to move the valve core in the direction far away from the external control port K, the larger the oil pressure of the external control port K is, the smaller the pressure of the oil outlet C is, and the larger the flow of the main pump is. In order to meet the flow requirements of different newly-added mechanisms, a spring with specific elasticity can be arranged to limit the maximum flow of the main pump, and the minimum flow of the main pump can be adjusted by adjusting an adjusting screw.
The newly-added proportional pressure reducing valve is a manual proportional pressure reducing valve, the manual proportional pressure reducing valve is provided with an operating handle, when the amplitude of the operating handle is larger, the oil pressure of a corresponding signal oil port A or a signal oil port B is larger, the oil pressure of a corresponding comparison valve outlet is larger, the oil pressure obtained by an external control port K is larger, the oil pressure obtained by an oil outlet C and a flow control valve is smaller, the flow of a main pump is larger, and the flow obtained by an actuating mechanism corresponding to the manual proportional pressure reducing valve is larger.
Further, when the number of the newly added function valves is two, the outlets of the comparison valves included in the two groups of newly added function valves need to be connected to two inlets of the second comparison valve 64 for secondary comparison, and then flow into the external control port K through the outlets of the second comparison valve, if there are three groups, the comparison valve included in the third group of newly added function valves should be compared with the outlet pressure of the second comparison valve, and the subsequent group of newly added function valves is also analogized in sequence, so that the group of execution mechanisms with the largest flow demand can obtain the required flow when there are multiple groups of newly added execution mechanisms acting. The second-stage comparison valve and other comparison valves can adopt shuttle valves.
Further, an overflow valve 41 is connected to an outlet of the pilot pump, and a filter 42 is arranged on a pipeline at one end of an inlet of the overflow valve.
The invention has at least the following beneficial effects:
the invention provides a hydraulic system based on a negative flow control system, which is additionally provided with a flow regulation and control pressure reducing valve, a second selection valve and a first selection valve on the basis of the existing negative flow control system.
The invention can realize that a newly added function valve group is arranged on the basis of the existing negative flow control system without adding a new pump, and the valve group is connected to the original flow control valve through the flow regulation and control pressure reducing valve to control the flow of the main pump, so that a newly added actuating mechanism obtains the required flow, and the requirement of the action added by the newly added actuating mechanism on the flow diversity of the system can be realized. The maximum flow of the main pump can be limited by changing the parameters of the spring in the flow regulation and control pressure reducing valve, the minimum flow of the pump can be adjusted by the adjusting screw of the pressure reducing valve, the newly-added functional valve group can be selected from valve groups with the same structure as the original functional valve group of the system, the operation is simple and convenient, the feasibility is high, and the application range of the original negative flow control system is effectively expanded. Correspondingly, the excavator hydraulic system is applied to the piling machinery or other multifunctional engineering machinery after being subjected to function expansion, and the application is very easy to realize.
In addition to the objects, features and advantages described above, other objects, features and advantages of the present invention are also provided. The present invention will be described in further detail below with reference to the drawings.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:
FIG. 1 is a schematic diagram of a conventional negative flow control system;
FIG. 2 is a schematic diagram of a hydraulic system based on a negative flow control system according to a first preferred embodiment of the present invention;
FIG. 3 is an internal structure view of a flow regulating pressure reducing valve according to a first preferred embodiment of the present invention;
fig. 4 is a schematic structural diagram of a hydraulic system based on a negative flow control system according to a second preferred embodiment of the present invention.
In the figure: 1-a feedback valve, 2-a switch valve, 3-a main pump, 4-a pilot pump, 41-an overflow valve, 42-a filter, 5-a flow control valve, 16-a function valve (original function valve), 161-a hydraulic control reversing valve (original hydraulic control reversing valve), 162-a proportional reducing valve (original proportional reducing valve), 6-a newly-added function valve, 61-a newly-added hydraulic control reversing valve, 62-a newly-added proportional reducing valve, 63-a comparison valve, 64-a second comparison valve, 7-a first selection valve, 8-a second selection valve, 9-a flow regulation reducing valve, 90-a valve body, 91-a valve cavity, 92-a valve core, 93-a spring, 94-an adjusting screw, 95-a screw hole, 96-an oil drain port and 97-a throttling structure I.
Detailed Description
Embodiments of the invention will be described in detail below with reference to the drawings, but the invention can be implemented in many different ways, which are defined and covered by the claims.
Referring to fig. 2, a first embodiment of the hydraulic system based on the negative flow control system of the excavator includes a feedback valve 1, a main pump 3, a pilot pump 4, a flow control valve 5, a second selection valve 8, and a new function valve 6 of a flow control pressure reducing valve 9, each group of the new function valves includes a comparison valve 63, a new hydraulic control directional valve 61 and a new proportion pressure reducing valve 62 for controlling the new hydraulic control directional valve, an oil inlet of the new proportion pressure reducing valve included in each new function valve and an oil inlet of an original proportion pressure reducing valve included in an original function valve are connected in parallel to an outlet of the pilot pump, and an oil inlet of the new hydraulic control directional valve included in each new function valve and an oil inlet of the original hydraulic control directional valve included in the original function valve are connected in parallel to an outlet. The excavator negative flow control system generally comprises seven groups of original function valves, only three groups are shown in the application in fig. 2 and 3, and the other four groups are not shown.
The new proportion relief pressure valve is provided with a signal oil port A and a signal oil port B, the signal oil port A and the signal oil port B are respectively connected to two hydraulic control signal ports of the new hydraulic control reversing valve, the comparison valve 63 is further connected between the signal oil port A and the signal oil port B, two oil inlets of the comparison valve are respectively connected with the signal oil port A and the signal oil port B, the flow regulation and control relief pressure valve is provided with an outer control port K, an oil outlet of the comparison valve is connected with the outer control port K of the flow regulation and control relief pressure valve, and pressure oil flowing out of an oil outlet of the comparison valve is pressure oil of one signal oil port with large pressure in the signal oil port A and the.
An oil inlet J of the flow regulation and control pressure reducing valve 9 is connected to the outlet of the pilot pump, and the internal structure of the flow regulation and control pressure reducing valve is set as follows: the maximum oil pressure and the minimum oil pressure of the oil outlet C can be adjusted (the maximum oil pressure and the minimum oil pressure of the oil outlet C can be adjusted according to the flow required by a newly-added executing mechanism), the larger the oil inlet pressure of the external control port K is, the smaller the oil outlet pressure of the oil outlet C is, the oil outlet C of the flow regulation and control pressure reducing valve is connected to the second selector valve, the inlet of the feedback valve 1 is communicated with a second selection valve, the outlet of the second selection valve is connected to the flow control valve 5, the second selection valve is used for switching the flow control valve between two states of being communicated with the feedback valve or the flow regulating and reducing valve, thereby leading the main pump to carry out flow regulation and control by the original feedback valve 1 when driving the original actuating mechanism, and to carry out flow regulation and control by the flow regulation and control pressure reducing valve when driving the newly added actuating mechanism, the functions of the original function valve and the original actuating mechanism are not influenced, and meanwhile, the newly added actuating mechanism can obtain the required flow during working.
The hydraulic system based on the negative flow control system in the first embodiment of the invention comprises a switch valve 2, wherein the switch valve 2 is connected to the tail ends of oil paths of all the original liquid control reversing valves which are connected in parallel and is positioned at the upstream of a feedback valve, the tail ends of all the groups of original liquid control reversing valves which are connected in parallel are sequentially communicated with an oil tank through the switch valve and the feedback valve, hydraulic oil from a main pump passes through all the groups of original function valves, then passes through the switch valve 2 and then flows to the inlet of the feedback valve 1, and the switch valve 2 is used for closing the oil paths between all the original liquid control reversing valves and the feedback valve when a flow control pressure reducing valve and a flow control valve are communicated.
The hydraulic system based on the negative flow control system comprises a first selection valve 7, an oil outlet of a comparison valve is divided into two paths, one path is connected with an external control port K of the flow regulation and reduction valve, the other path is connected with an oil inlet of the first selection valve, the switch valve is a two-position two-way hydraulic control reversing valve, the oil outlet of the first selection valve is connected with a pilot control oil port of the switch valve, and the first selection valve is used for enabling pilot oil of the switch valve to be communicated to obtain reversing power when the switch valve needs to close an oil path between each original hydraulic control reversing valve and a feedback valve.
In the first embodiment of the invention, the comparison valve is a shuttle valve, and the first selection valve and the second selection valve are two-position four-way electromagnetic reversing valves.
In the first embodiment of the present invention, the outlet of the pilot pump is connected to an overflow valve 41, a filter 42 is disposed on a pipeline at one end of the inlet of the overflow valve, and the outlet of the overflow valve is connected to a connection pipeline between the main pump and the oil tank, so as to simplify the pipeline and save the installation space.
Referring to fig. 3, in the first embodiment of the present invention, the flow rate regulation and reduction valve 9 includes a valve body 90, a valve core 92, a spring 93 and an adjusting screw 94, a valve cavity 91 is disposed in the valve body, an oil inlet J, an oil outlet C and an external control port K are all communicated with the valve cavity, a throttle structure 97 is disposed between an inner wall of the valve cavity at the oil outlet C and the valve core, the valve core is disposed in the valve cavity, the valve body is provided with a screw hole 95 leading into the valve cavity, the valve body is further provided with an oil drain port 96 leading into the screw hole and used for communicating with an oil tank, the adjusting screw is screwed in the screw hole, the spring is abutted between the adjusting screw and the valve core, an elastic force direction of the spring is disposed along a direction pointing to the external control port K, the oil inlet J and the oil outlet C are in a normally open state, when pressure oil at the external control port K overcomes, the pressure of the oil outlet C becomes smaller, the larger the oil pressure of the external control port K is, the smaller the pressure of the oil outlet C is.
In the first embodiment of the invention, the newly-added proportional pressure reducing valve is a manual proportional pressure reducing valve, the manual proportional pressure reducing valve is provided with an operating handle, when the amplitude of the operating handle is larger, the oil pressure of the corresponding signal oil port a or signal oil port B is larger, the oil pressure of the corresponding outlet of the comparison valve is larger, the oil pressure obtained by the external control port K is larger, the oil pressure obtained by the oil port C and the flow control valve is smaller, the flow of a main pump is larger, and the flow obtained by the actuating mechanism corresponding to the manual proportional pressure reducing valve is larger.
Referring to the second embodiment of fig. 4, in the second embodiment, the number of the newly added function valves is two, outlets of the comparison valves included in the two groups of newly added function valves are respectively connected to two inlets of the second-stage comparison valve 64 for secondary comparison, and then flow into the external control port K through an outlet of the second-stage comparison valve, so that the pressure obtained by the external control port K is the pressure value of a certain signal port a or a signal port B with the largest pressure value, thereby ensuring that the action of the corresponding actuator requiring the largest flow rate is completed. And the two-stage comparison valve and the comparison valve of the second group of newly added function valves are shuttle valves. The other structure of the second embodiment is the same as that of the first embodiment.
Referring to fig. 2 to 4, the working process and principle of the first and second embodiments of the present invention are as follows:
when the original function valve group is used, the second selection valve is switched to the left position, the first selection valve is switched to the right position, all original liquid control reversing valves and feedback valves included in the original function valve are in a communicated state, the inlet of the feedback valve and the flow control valve are also in a communicated state, and the flow of the main pump is regulated by the feedback valve and the flow control valve together.
When a new function valve group is used, the second selection valve is switched to the right position, the first selection valve is switched to the left position, at the moment, each original hydraulic control reversing valve and each feedback valve which are included in the original function valve are in an off state, the inlet of each feedback valve and the flow control valve are also in an off state, the flow regulation and control pressure reducing valve and the flow control valve are in an on state, and a pressure signal can be provided for an outer control port K of the flow regulation and control pressure reducing valve just by operating a handle of the new proportion pressure reducing valve like operating the handle of the original proportion pressure reducing valve, so that the flow of the main pump is regulated and controlled.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A hydraulic system based on a negative flow control system is characterized by comprising a feedback valve (1), a main pump (3), a pilot pump (4), a flow control valve (5), a second selection valve (8), a flow regulation and control pressure reducing valve (9) and a plurality of groups of newly added function valves (6), wherein each newly added function valve is connected with an original function valve (16) in parallel, and each group of newly added function valves comprises a comparison valve (63), a newly added hydraulic control reversing valve (61) and a newly added proportional pressure reducing valve (62) for controlling the newly added hydraulic control reversing valve;
each group of the original function valves (16) comprises a hydraulic control reversing valve (161) and a proportional pressure reducing valve (162) corresponding to the hydraulic control reversing valve;
the newly-added proportional pressure reducing valve is provided with a signal oil port A and a signal oil port B, the signal oil port A and the signal oil port B are respectively connected to two hydraulic control signal ports of the newly-added hydraulic control reversing valve, the comparison valve (63) is further connected between the signal oil port A and the signal oil port B, the flow regulating pressure reducing valve is provided with an outer control port K, and the oil outlet of the comparison valve is connected with the outer control port K of the flow regulating pressure reducing valve;
an oil inlet J of the flow regulation and control pressure reducing valve (9) is connected to the outlet of the pilot pump, and the internal structure of the flow regulation and control pressure reducing valve is set as follows: the maximum oil pressure and/or the minimum oil pressure of the oil outlet C can be adjusted, the oil outlet C of the flow regulating and reducing valve is connected to the second selection valve, the inlet of the feedback valve (1) is communicated with the second selection valve, the outlet of the second selection valve is connected to the flow control valve (5), and the second selection valve is used for enabling the flow control valve to be switched between two states of being communicated with the feedback valve or being communicated with the flow regulating and reducing valve.
2. The hydraulic system based on the negative flow control system as claimed in claim 1, further comprising a switch valve (2), wherein the switch valve is connected to the end of the oil path of each raw hydraulic control directional control valve after being connected in parallel and is located at the upstream of the feedback valve, and the end of each group of raw hydraulic control directional control valves after being connected in parallel is sequentially communicated with the oil tank through the switch valve and the feedback valve.
3. The hydraulic system based on the negative flow control system as claimed in claim 2, further comprising a first selection valve (7), wherein an oil outlet of the comparison valve is divided into two paths, one path is connected to the external control port K of the flow regulation and control pressure reducing valve, the other path is connected to an oil inlet of the first selection valve, the switch valve is a hydraulic control reversing valve, and the oil outlet of the first selection valve is connected to a pilot control oil port of the switch valve.
4. The hydraulic system as recited in claim 3 wherein the comparison valve is a shuttle valve and the first and second selector valves are solenoid operated directional valves.
5. The hydraulic system of claim 1, wherein the pressure oil flowing out of the oil outlet of the comparison valve is the pressure oil of one of the signal port a and the signal port B with a larger pressure, the newly added proportional pressure reducing valve is a manual proportional pressure reducing valve with an operating handle, and the manual proportional pressure reducing valve is configured to: when the amplitude of the operating handle is larger, the oil pressure of the corresponding signal oil port A or the signal oil port B is larger, the oil pressure of the outlet of the corresponding comparison valve is larger, the oil pressure obtained by the outer control port K is larger, the oil pressure obtained by the oil outlet C and the flow control valve is smaller, the flow of the main pump is larger, and the flow obtained by the actuating mechanism corresponding to the manual proportional pressure reducing valve is larger.
6. A hydraulic system based on a negative flow control system according to claim 1, characterized in that the number of said new functional valves is two, and the outlets of the comparison valves included in the two new functional valves are connected to the two inlets of the second comparison valve (64) for secondary comparison and then flow into the external control port K through the outlet of the second comparison valve.
7. The hydraulic system as recited in claim 6 wherein the secondary comparison valve is a shuttle valve.
8. The hydraulic system based on the negative flow control system according to claim 1, characterized in that a relief valve (41) is connected to the outlet of the pilot pump, and a filter (42) is arranged on a pipeline at one end of the inlet of the relief valve.
9. The hydraulic system based on the negative flow control system as claimed in any one of claims 1 to 8, wherein the flow control pressure reducing valve (9) comprises a valve body (90), a valve core (92), a spring (93) and an adjusting screw (94), a valve cavity (91) is arranged in the valve body, an oil inlet J, an oil outlet C and an external control port K are all communicated with the valve cavity, a throttling structure (97) is arranged between the inner wall of the valve cavity at the oil outlet C and the valve core, the valve core is arranged in the valve cavity, a screw hole (95) leading into the valve cavity is arranged on the valve body, the adjusting screw is screwed in the screw hole, the spring is abutted between the adjusting screw and the valve core, the elastic force direction of the spring is arranged along the direction pointing to the external control port K, and the oil inlet J and the oil outlet C are.
10. The hydraulic system based on the negative flow control system as claimed in claim 9, wherein the valve body is further provided with a drain port (96) which is communicated with the oil tank and leads into the screw hole.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010048359A (en) * | 2008-08-22 | 2010-03-04 | Sumitomo (Shi) Construction Machinery Co Ltd | Pump control circuit of construction machine |
| CN102410267A (en) * | 2011-11-03 | 2012-04-11 | 徐州雷曼机械科技有限公司 | Synchronous control device of revolving speed of hydraulic walking mechanism engine and discharge of main pump |
| CN106499681A (en) * | 2016-12-27 | 2017-03-15 | 恒天九五重工有限公司 | A kind of power control system of hydraulic excavator |
| CN107701532A (en) * | 2017-11-16 | 2018-02-16 | 恒天九五重工有限公司 | Minus flow banked direction control valves hydraulic control system and its control method |
| CN108286538A (en) * | 2017-01-10 | 2018-07-17 | 斗山英维高株式会社 | The hydraulic system of engineering machinery |
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2018
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010048359A (en) * | 2008-08-22 | 2010-03-04 | Sumitomo (Shi) Construction Machinery Co Ltd | Pump control circuit of construction machine |
| CN102410267A (en) * | 2011-11-03 | 2012-04-11 | 徐州雷曼机械科技有限公司 | Synchronous control device of revolving speed of hydraulic walking mechanism engine and discharge of main pump |
| CN106499681A (en) * | 2016-12-27 | 2017-03-15 | 恒天九五重工有限公司 | A kind of power control system of hydraulic excavator |
| CN108286538A (en) * | 2017-01-10 | 2018-07-17 | 斗山英维高株式会社 | The hydraulic system of engineering machinery |
| CN107701532A (en) * | 2017-11-16 | 2018-02-16 | 恒天九五重工有限公司 | Minus flow banked direction control valves hydraulic control system and its control method |
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| CN109458370A (en) | 2019-03-12 |
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