CN102434502B - Frequency-conversion pump controlled steering hydraulic system for loader - Google Patents
Frequency-conversion pump controlled steering hydraulic system for loader Download PDFInfo
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- CN102434502B CN102434502B CN201110437880.5A CN201110437880A CN102434502B CN 102434502 B CN102434502 B CN 102434502B CN 201110437880 A CN201110437880 A CN 201110437880A CN 102434502 B CN102434502 B CN 102434502B
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Abstract
The invention relates to a frequency-conversion pump controlled steering hydraulic system for a loader, wherein an alternating-current motor driven constant delivery pump is used as a main oil supply source, an energy accumulator is used as an auxiliary oil supply source. At the initial steering stage of the loader, the energy accumulator supplies oil to a steering hydraulic cylinder independently; after an alternating-current motor is started, the alternating-current motor driven constant delivery pump supplies oil to the steering hydraulic cylinder independently; through the mode, the response speed of a steering system is increased, and the energy consumption is saved at the same time; and after the loader is started, if the pressure in the energy accumulator is lower, the alternating-current motor driven constant delivery pump is used for injecting high-pressure oil liquid to the energy accumulator. The hydraulic system disclosed by the invention has the main advantage of high efficiency.
Description
Technical field
Patent of the present invention relates to a kind of energy-saving loading machine steering hydraulic system, belongs to Construction Machinery Energy Saving field.
Background technique
At present, the system fuel system of loading machine steering hydraulic pressure system mainly contains two kinds: 1. adopt metering pump to steering hydraulic oil supply cylinder, 2. adopt variable displacement pump to steering hydraulic oil supply cylinder.The advantage of metering pump fuel system is that cost is low, and reliability is higher; Shortcoming is that efficiency is very low, probably between 10% ~ 30%.Inefficient reason is mainly: 1. domestic 50 loaders of take are example, for security consideration, when the operation of loader engine idle (750r/min left and right), metering pump should be able to provide enough fluid to hydraulic steering cylinder, and during loader normal operation the rotating speed of motor generally in 1700r/min left and right, the fluid of now metering pump output has surpassed the demand of hydraulic steering cylinder to hydraulic oil, and unnecessary fluid flows back to fuel tank through valve, produces more restriction loss; 2. when loader does not turn to, metering pump, still with lower Output pressure hydraulic oil, produces larger energy loss.The advantage of variable displacement pump fuel feeding is that efficiency is high; Deficiency is mainly: cost is high, safeguards more complicatedly, and domestic variable displacement pump reliability is not high, and therefore domestic low and middle-grade loaders still adopt metering pump in a large number.
Summary of the invention
The present invention proposes a kind of novel loader variable frequency pump control steering hydraulic system, to overcome the lower deficiency of existing loading machine steering system effectiveness.
Technological scheme one of the present invention: comprise hydraulic steering cylinder (11), accumulator (12), controller (9), steering wheel (8), AC motor (4), DC/AC transducer (3), storage battery (2), metering pump (6), fuel tank (1), Proportional valve (13), on-off valve (16), one-way valve (7), speed probe (5), pressure transducer (14), pressure transducer (15), relief valve (17), three position four-way directional control valve (10).Placement is: storage battery (2) drives AC motor (4), AC motor (4) drives metering pump (6), metering pump (6) outlet is connected with three position four-way directional control valve (10) through one-way valve (7), and three position four-way directional control valve (10) outlet is connected with hydraulic steering cylinder (11); Accumulator (12) outlet is connected with Proportional valve (13), and Proportional valve (13) outlet is connected with three position four-way directional control valve (10) import; Relief valve (17) one end is connected with metering pump (6) outlet, and one end passes into fuel tank (1); On-off valve (16) one end is connected with metering pump (6) outlet, and one end passes into fuel tank (1).Speed probe (5) is measured AC motor (4) rotating speed; Pressure transducer (14) is measured accumulator (12) outlet pressure, pressure transducer (15) is measured three-position four-way valve inlet pressure.Pressure transducer (14), pressure transducer (15) are with the output signal of speed probe (5) in controller (9), and controller (9) is controlled storage battery (2), Proportional valve (13), on-off valve (16), three position four-way directional control valve (10).Wherein AC motor (4) can be synchronous AC motor or asynchronous AC motor; Three position four-way directional control valve (10), Proportional valve (13), on-off valve (16) can adopt solenoid valve for small flow system, to Mass flow system, can adopt electro hydraulic valve.
Technological scheme two of the present invention is with the difference of technological scheme one: add fuel cell (19) and DC/DC transducer (18); Fuel cell (19) output electric energy is stored in storage battery (2) through DC/DC transducer (18), and storage battery (2) is driving AC motor (4) through DC/AC transducer (3); Fuel cell (19) only drives the AC motor (4) of this steering system, and other portion of energy demands of loader are provided by the internal-combustion engine of loader, and this driving mode can reduce the requirement to fuel cell (19) power.
During loading machine steering first by accumulator (12) separately to hydraulic steering cylinder (11) fuel feeding, open on-off valve (16) so that No Load Start AC motor simultaneously, when AC motor (4) rotating speed reaches required value, switching to by AC motor (4) driving metering pump (6) separately to hydraulic steering cylinder (11) fuel feeding.Turn to after end, three position four-way directional control valve (10) is closed, when accumulator (12) internal pressure is lower, close on-off valve (16), open Proportional valve (13), AC motor (4) continues to drive metering pump (6) rotation, to accumulator (12), be filled with high-voltage oil liquid, during oil-filled to accumulator (12), if loader need to turn to, close Proportional valve (13), open three position four-way directional control valve (10), AC motor (4) drives metering pump (6) to hydraulic steering cylinder (11) fuel feeding; When accumulator (12) internal pressure is higher, open on-off valve (16), close Proportional valve (13), and stop to AC motor (4) power supply AC motor (4) braking.If steering wheel (8) movement range is little, before AC motor (4) rotating speed reaches required value, steering wheel (8) just stops action, after steering wheel (8) stops action, detects at once the pressure of accumulator (12); If the higher AC motor (4) that makes of accumulator (12) pressure is braked, if accumulator internal pressure is lower, continue to AC motor (4) power supply, AC motor (4) drives metering pump (6) accumulator (12) oil-filled.
The beneficial effect of patent of the present invention is: 1 efficiency is high, when loader does not turn to and when accumulator internal pressure is higher, AC motor is not worked, idling products Energy Intensity Reduction; When loading machine steering, according to the speed turning to, adjust AC motor rotating speed, realize the fuel feeding as required to hydraulic steering cylinder, reduce restriction loss.The startability of 2 pairs of AC motor requires low, due to turn to the starting stage by accumulator separately to oil hydraulic cylinder fuel feeding, AC motor starts under unloaded situation, does not therefore require that AC motor possesses very high starting performance.
Accompanying drawing explanation
Below in conjunction with drawings and embodiments, the present invention will be further described.
Fig. 1 is the system schematic of technical solution of the present invention one.
Fig. 2 is the system schematic of technical solution of the present invention two.
Fig. 3 is the main flowchart of technical solution of the present invention one.
In Fig. 1: 1. fuel tank, 2. storage battery, 3. DC/AC transducer, 4. AC motor, 5. speed probe, 6. metering pump, 7. one-way valve, 8. steering wheel, 9. controller, 10. three position four-way directional control valve, 11. hydraulic steering cylinders, 12. accumulators, 13. Proportional valves, 14. pressure transducers, 15. pressure transducers, 16. on-off valves, 17. relief valves; Fig. 1 mid point is scribed ss sensor signal.
In Fig. 2: 1. fuel tank, 2. storage battery, 3. DC/AC transducer, 4. AC motor, 5. speed probe, 6. metering pump, 7. one-way valve, 8. steering wheel, 9. controller, 10. three position four-way directional control valve, 11. hydraulic steering cylinders, 12. accumulators, 13. Proportional valves, 14. pressure transducers, 15. pressure transducers, 16. on-off valves, 17. relief valves, 18.DC/DC transducer, 19. fuel cells; Fig. 2 mid point is scribed ss sensor signal.
Embodiment
The embodiment of technical solution of the present invention one: when loader starts, pressure transducer (14) is transferred to the pressure signal of accumulator (12) on controller (9), controller (9) judges whether the pressure of accumulator (12) meets the requirements, when accumulator (12) internal pressure is lower, controller (9) is controlled AC motor (4) and is started, and control ratio valve (13) is opened, three position four-way directional control valve (10) and on-off valve (16) are closed, now, metering pump (6) is filled with high-voltage oil liquid to accumulator (12) under AC motor (4) drives, when accumulator (12) pressure is higher, loader can start normal operation.The interior maximum pressure of accumulator (12) is relief valve (17) oil pressure relief, the middle pressure of hydraulic steering cylinder when minimum pressure should be greater than loader normal direction of rotation (11), and during hydraulic steering cylinder (11) normal direction of rotation, middle pressure can be measured by experiment.
When loader need to turn to, turning in the incipient time period, be that AC motor (4) rotating speed does not reach before setting rotating speed, by accumulator (12) to hydraulic steering cylinder (11) fuel feeding, when AC motor (4) rotating speed reaches, set after rotating speed, by AC motor (4), driving metering pump (6) to hydraulic steering cylinder (11) fuel feeding; The setting rotating speed of AC motor (4) is directly proportional to steering wheel (8) action speed; The major advantage of this fuel supply method is: 1. the fast response time of accumulator (12), in the loading machine steering starting stage by accumulator (12) separately to hydraulic steering cylinder (11) fuel feeding, the feature that meets loader requirement steering system fast response time, 2. in steering procedure, AC motor (4) rotating speed can be according to the adjustment of steering wheel (8) action speed, export as required fluid to hydraulic steering cylinder (11), save energy.Its detailed process is as follows: when controller (9) is received turn signal, open on-off valve (16), start AC motor (4), metering pump (6) output fluid flows back to fuel tank (1) through on-off valve (16), AC motor (4) is equivalent to start under zero load, and rise of rotational speed is very fast; Open Proportional valve (13), three position four-way directional control valve (10) simultaneously, by accumulator (12) separately to hydraulic steering cylinder (11) fuel feeding, the openings of sizes of Proportional valve (13) calculates according to three-position four-way valve (9) inlet pressure, accumulator (12) outlet pressure, guarantees that the fluid in accumulator (12) can not cause excessive shock to hydraulic steering cylinder (11) because Proportional valve (13) opening is excessive; After AC motor (4) has started, close Proportional valve (13) and on-off valve (16), transfer by metering pump (6) separately to steering hydraulic system fuel feeding.
Turn to while finishing, close three position four-way directional control valve (10), if accumulator (12) internal pressure is not less than minimum authorized pressure, open on-off valve (16), stop to AC motor (4) power supply, AC motor (4) rotating speed reduces gradually simultaneously, realizes AC motor (4) braking, if accumulator (12) internal pressure is less than minimum authorized pressure, on-off valve (16) is closed with three position four-way directional control valve (10), Proportional valve (13) is opened, storage battery (2) continues to power to AC motor (4), AC motor (4) drives metering pump (6) to be filled with high-voltage oil liquid to accumulator (12), during oil-filled to accumulator (12), if loader need to turn to, close Proportional valve (13), open three position four-way directional control valve (10), AC motor (4) drives metering pump (6) to hydraulic steering cylinder (11) fuel feeding, if loader does not need to turn to, when accumulator (12) pressure reaches Maximum allowable pressure, close Proportional valve (13), open on-off valve (16) simultaneously and stop powering to AC motor (4), AC motor (4) braking.
In actual job, may there is following situation: steering wheel (8) movement range is less, before AC motor (4) rotating speed reaches required value, steering wheel (8) just stops action, after steering wheel (8) stops action, closes three position four-way directional control valve (10) and detects the pressure of accumulator (12); If the higher AC motor (4) that makes of accumulator (12) pressure is braked, if accumulator internal pressure is lower, continue to power to AC motor (4), AC motor (4) drives metering pump (6) oil-filled to accumulator (12), and AC motor (4) braking process is with identical with the discussion of the preceding paragraph to accumulator (12) Oil feeding process.
When loader does not turn to, and accumulator (12) pressure is not little when allowing minimum pressure, and AC motor (4) is not worked.The main execution flow process of technological scheme one is expressed in Fig. 3.
The embodiment of technical solution of the present invention two: technological scheme two is power source part with the difference of technological scheme one; In technological scheme two, add fuel cell (19) and DC/DC transducer (18); Fuel cell (19) output electric energy is stored in storage battery (2) through DC/DC transducer (18), and storage battery (2) is driving AC motor (4) through DC/AC transducer (3); Fuel cell (19) only drives the AC motor (4) of this steering system, and other portion of energy demands of loader are provided by the internal-combustion engine of loader; Fuel cell system can further improve system effectiveness, and not high to fuel cell (19) power requirements.
Because the combination of AC motor (4) and metering pump (6) can be oily to the demand output hydraulic pressure of fluid according to hydraulic steering cylinder (11), so three position four-way directional control valve (10) only plays the role of changing, do not play adjust flux effect.One of ideal performance that loading machine steering hydraulic system need to reach is: work as loading machine steering, and during the change of hydraulic steering cylinder (11) internal pressure, enter the flow of hydraulic steering cylinder (11), be not subject to hydraulic steering cylinder (11) pressure surge impact, and only steering wheel (8) rotating speed is directly proportional, the flow that enters hydraulic steering cylinder (11) fluctuates and has stronger robustness steering load; In patent of the present invention, for what try one's best, reach this performance and can to AC motor (4), carry out speed governing by vector control method, to improve the robustness of steering hydraulic system.
Claims (5)
1. a frequency-conversion pump controlled steering hydraulic system for loader, comprises hydraulic steering cylinder, accumulator, controller, steering wheel, AC motor, storage battery, DC/AC transducer, DC/DC transducer, fuel cell, metering pump, fuel tank, Proportional valve, on-off valve, one-way valve, speed probe, pressure transducer, relief valve, three position four-way directional control valve; AC motor drives metering pump; Metering pump outlet is connected with three position four-way directional control valve through one-way valve; Three position four-way directional control valve outlet is connected with hydraulic steering cylinder; Accumulator outlet is connected with three position four-way directional control valve filler opening through Proportional valve; Relief valve one end is connected with metering pump, and one end is connected with fuel tank; On-off valve one end is connected with metering pump, and one end is connected with fuel tank; Speed probe is transmitted to controller by AC motor tach signal; Pressure transducer is transmitted to controller by accumulator outlet pressure and three position four-way directional control valve inlet pressure; Controller control ratio valve, three position four-way directional control valve, on-off valve; Described frequency-conversion pump controlled steering hydraulic system for loader, it is characterized in that: in the loading machine steering starting stage, be that AC motor rotating speed does not reach before setting rotating speed, by accumulator separately to steering hydraulic oil supply cylinder, AC motor reaches to set and switches to after rotating speed by AC motor separately to steering hydraulic oil supply cylinder, and AC motor is set rotating speed and set according to steering wheel movement speed speed by controller; After loading machine steering finishes, if energy storage pressure is lower than setting minimum pressure, it is oil-filled to accumulator that AC motor continues to drive metering pump, if energy storage pressure is not less than in setting pressure, AC motor brake, if loader turns to during oil-filled to accumulator, stop to accumulator oil-filledly, AC motor drives metering pump to steering hydraulic oil supply cylinder; If reach setting rotating speed front steering process in AC motor, just finish, after turning to end, judging whether at once need to be oil-filled to accumulator; Three position four-way directional control valve only plays the role of changing, and does not play adjust flux effect; Controller is set up the aperture of Proportional valve according to three position four-way directional control valve inlet pressure and accumulator outlet pressure; Power source part, for common loader, drives separately AC motor by storage battery, or forms hybrid power source driving AC motor by fuel cell and storage battery.
2. frequency-conversion pump controlled steering hydraulic system for loader according to claim 1, is characterized in that: controller is adjusted AC motor rotating speed according to steering wheel action speed, and AC motor is set rotating speed and is directly proportional to steering wheel movement speed.
3. frequency-conversion pump controlled steering hydraulic system for loader according to claim 1, it is characterized in that: at loading machine steering, just start AC motor the zero hour, at AC motor rotating speed, do not reach and set before rotating speed, open on-off valve, make AC motor No Load Start, open Proportional valve simultaneously, make accumulator separately to steering hydraulic oil supply cylinder; AC motor reaches to be set after rotating speed, closes on-off valve and Proportional valve, by AC motor separately to steering hydraulic oil supply cylinder; Turn to after end, close three position four-way directional control valve; If accumulator internal pressure is lower than setting minimum pressure, on-off valve is closed, Proportional valve is opened, AC motor drives metering pump to be filled with high-voltage oil liquid to accumulator, during oil-filled to accumulator, if loader need to turn to, close Proportional valve, on-off valve, open three position four-way directional control valve, AC motor drives metering pump to steering hydraulic oil supply cylinder; If accumulator internal pressure is not less than setting minimum pressure, stop to AC motor power supply, and open on-off valve, close three position four-way directional control valve and Proportional valve, AC motor brake; The setting maximum pressure of accumulator is relief valve oil pressure relief, the middle pressure of hydraulic steering cylinder when the minimum setting pressure of accumulator is greater than loader normal direction of rotation, and during loader normal direction of rotation, the middle pressure of hydraulic steering cylinder is measured by experiment.
4. frequency-conversion pump controlled steering hydraulic system for loader according to claim 1, it is characterized in that: at loading machine steering, just start AC motor the zero hour, if reach setting rotating speed front steering process in AC motor, just finish, close three position four-way directional control valve; If accumulator internal pressure is lower than setting minimum pressure, on-off valve is closed, Proportional valve is opened, AC motor continues to drive metering pump oil-filled to accumulator, during oil-filled to accumulator, if loader need to turn to, close Proportional valve, on-off valve, open three position four-way directional control valve, AC motor drives metering pump to steering hydraulic oil supply cylinder; If accumulator internal pressure is not less than setting minimum pressure, stop to AC motor power supply, and open on-off valve, close three position four-way directional control valve and Proportional valve, AC motor brake.
5. frequency-conversion pump controlled steering hydraulic system for loader according to claim 1, is characterized in that: fuel cell output electric energy is stored in storage battery through DC/DC transducer, and storage battery drives AC motor through DC/AC transducer again; Fuel cell only drives the AC motor of this steering hydraulic system, and other portion of energy demands of loader are provided by the internal-combustion engine of loader.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201110437880.5A CN102434502B (en) | 2011-12-23 | 2011-12-23 | Frequency-conversion pump controlled steering hydraulic system for loader |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201110437880.5A CN102434502B (en) | 2011-12-23 | 2011-12-23 | Frequency-conversion pump controlled steering hydraulic system for loader |
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| CN102434502A CN102434502A (en) | 2012-05-02 |
| CN102434502B true CN102434502B (en) | 2014-08-13 |
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| CN201110437880.5A Expired - Fee Related CN102434502B (en) | 2011-12-23 | 2011-12-23 | Frequency-conversion pump controlled steering hydraulic system for loader |
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Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102635143B (en) * | 2012-05-04 | 2014-06-11 | 山东理工大学 | Energy-saving hydraulic control system of loading machine and control method |
| CN103062165B (en) * | 2013-01-10 | 2016-04-20 | 江苏奥新新能源汽车有限公司 | Hydraulic power system and the application in new-energy automobile thereof |
| CN103112804B (en) * | 2013-02-05 | 2015-10-28 | 浙江诺力机械股份有限公司 | A kind of control setup of industrial vehicle lifting mechanism and control method |
| DE102014213264A1 (en) * | 2013-08-19 | 2015-02-19 | Robert Bosch Gmbh | Hydraulic arrangement for supplying a consumer |
| CN104925129B (en) * | 2015-07-16 | 2017-11-10 | 潍柴动力股份有限公司 | Hydraulic steering system |
| CN105257605B (en) * | 2015-11-06 | 2017-05-10 | 杨贝贝 | Energy conversation method and energy conversation device for pressure control hydraulic systems |
| CN106801688A (en) * | 2015-11-26 | 2017-06-06 | 衡阳市利美电瓶车制造有限责任公司 | A kind of railless electric flatcar hydraulic power unit |
| CN105507362B (en) * | 2016-01-24 | 2017-11-14 | 吉林大学 | Without spill losses loader hydraulic system and its control method |
| CN107327426B (en) * | 2016-01-28 | 2018-10-19 | 佛山市佛锐达机电科技有限公司 | A kind of force control hydraulic pressure energy saving of system method and its energy saver |
| CN106762928B (en) * | 2017-01-17 | 2018-10-16 | 徐工集团工程机械有限公司 | Automobile hydraulic system and engineering truck with it |
| CN112594240B (en) * | 2020-12-24 | 2023-02-03 | 山推工程机械股份有限公司 | Hydraulic system of working device, control method and electric loader |
| CN113153854A (en) * | 2021-04-30 | 2021-07-23 | 湖南星邦智能装备股份有限公司 | Hybrid power hydraulic system and overhead working truck |
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| JP2885903B2 (en) * | 1990-08-03 | 1999-04-26 | 本田技研工業株式会社 | Fluid pressure supply device for vehicles |
| DE102008038520A1 (en) * | 2008-08-20 | 2010-02-25 | Robert Bosch Gmbh | Device for providing a pressure for a hydraulic consumer and method for providing a pressure |
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|---|---|---|---|---|
| CN1391146A (en) * | 2002-07-23 | 2003-01-15 | 浙江大学 | Electro-hydraulic control system and method based on frequency-conversion speed regulation |
| CN102278334A (en) * | 2011-07-22 | 2011-12-14 | 中国人民解放军装甲兵工程学院 | Hydraulic power system for robot |
Non-Patent Citations (1)
| Title |
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| JP平4-90951A 1992.03.24 |
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