CN101392769B - High precision hydraulic power source for directly driving oil pump by speed governing generator - Google Patents
High precision hydraulic power source for directly driving oil pump by speed governing generator Download PDFInfo
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Abstract
The invention discloses a high-precision hydraulic power source which uses a speed regulating motor to drive an oil pump directly, and belongs to the technical field of hydraulic power installation. The high-precision hydraulic power source comprises an actuating mechanism, a reversing valve, an oil tank, servo drive units, a data acquisition and control system, and a feedback unit, wherein the reversing valve is connected with the actuating mechanism, the servo drive units are connected with the reversing valve, the data acquisition and control system is connected with the servo drive units, the feedback unit is connected with the data acquisition and control system, and the actuating mechanism is connected with the feedback unit; and the servo drive units have two groups which are parallelly connected with the reversing valve, one group of the servo drive units is in charge of controlling the oil feed for the actuating mechanism, while the other group is in charge of controlling the oil discharge for the actuating mechanism. The high-precision hydraulic power source has the advantages of energy conservation and high control precision.
Description
Technical field
The invention discloses and a kind ofly directly drive the high precision hydraulic power source of oil pump, belong to the hydraulic power control gear, can be widely used in the technical field that has High Accuracy Control to require to power, displacement, speed to various with speed-adjustable motor.
Background technique
As everyone knows, hydraulic power supply has been widely used in every field, mainly be to adopt common electric machine to drive the oil transportation in the clutch release slave cylinder of common metering pump, the delivery pressure and the movement speed of regulating power plant by modulating valve (Flow valve) or relief valve (pressure valve), advantage is to safeguard Dan Yi, so also have a large amount of hydraulic power supplies to adopt the method till now, shortcoming be oil pump flow is fuel-displaced causes the hydraulic oil temperature rise too high big all the time, thereby cause hydraulic system must adopt cooling equipment operation continuously.Variable displacement pump has appearred in the progress along with oil pump technology afterwards, on the basis of aforesaid hydraulic system, remove metering pump and modulating valve, adopt variable displacement pump, flow by the Moderator Variable pump reaches the movement speed of adjusting hydraulic pressure installation, but the method regulation range is subjected to the regulation range of variable displacement pump too little and the Flow-rate adjustment precision is not high, so only use under the less demanding situation of Flow-rate adjustment.In view of above situation, having occurred again with the variable displacement pump is that the basis adopts the flow closed loop control method to enlarge regulation range, but effect is little.Existing more advanced and accurate hydraulic power supply generally adopts the control system of valve combinations such as electro-hydraulic proportional valve or servovalve, adopts computer control, and its control effect and ratio of precision variable displacement pump want high.But, the machining accuracy of Proportional valve or servovalve etc. and to the requirement of hydraulic oil medium all than higher, hydraulic power system and control system heating value are big.
Above-mentioned the most essential a bit, no matter be in the hydraulic power unit of modulating valve control system, variable displacement pump control system, electro-hydraulic proportional valve, servovalve dispatch control system, no matter whether the powered actuation mechanism work of its control output, motor and hydraulic power unit are in running order all the time, and energy consumption is big.
For these reasons, the claimant has begun to propose the application for a patent for invention that application number is a kind of hydraulic power system with actuating motor control of 200710068074.9 in April, 2007, and this patent application is applied to fields such as injection machine, press machine, material testing machine, its more original hydraulic power supply, have advantages such as energy-conservation, low cost, obtained good economic benefit and social benefit.In October, 2007, the claimant was applied to this patent the development of 500kN, 0.03 grade of superposing type force standard machine, this machine is a kind of high-precision force measuring machine, dynamometry scope 20-500kN requires power value error≤0.03% in the dynamometry scope, power value fluctuation degree≤0.03%; Requirement to hydraulic power supply is: system pressure 20MPa, 0.8-20MPa scope internal force source fluctuation degree≤0.01% (≤0.00008MPa), find for the first time following situation (specifically being shown in Table 1) during test-run a machine:
1, to protect when carrying the fluctuation of power value bigger for low power value, and this moment, the actuating motor wave range was also bigger, and with the value of putting forth effort increase, fluctuation is dwindled;
2, power value overshoot: when being worth more energetically, load the certain power value of meeting overshoot when arriving the target force value, after the fluctuation of certain hour, be tending towards relatively stable.
Table 1 single servo motor is controlled the mean value oil pump after 50 tests of single oil pump
| Force-detecting position (kN) | Power value wave range (kN) | Actuating motor speed range (r/min) | Power value overshoot (kN) | The power value is tending towards the relatively stable time (s) |
| 20 | 19.850-20.163 | -10.1—13.2 | 0.508 | 60 |
| 50 | 49.914-50.102 | -1.6—17.5 | 0.250 | 47 |
| 100 | 99.975-50.027 | 18.2—22.5 | 0.114 | 30 |
| 200 | 199.995-200.004 | 39.4—40.1 | 0.067 | 21 |
| 300 | 299.998-300.002 | 65.2—65.7 | 0.054 | 13 |
| 500 | 499.999-500.002 | 101.3—101.5 | 0.048 | 10 |
According to above-mentioned data analysis, we can find that when actuating motor rotating speed (pump speed) was very low, the fluctuation of power value was big, along with rotating speed improves, tends towards stability.Actuating motor can move in the high rotational speed scope when making the force-detecting position of low power value, we once adopted the gap that enlarges oil cylinder and piston, attempt when hanging down the power value, can improve the rotating speed of actuating motor by the way that increases Leckage, when low power value, obtained effect preferably during test, but power is worth when higher, Leckage increases severely, and causes can not reaching the target force value at actuating motor (pump speed) in maximum fashion.
Through test, analysis repeatedly, we find it mainly is that following factor causes control accuracy not enough:
1, actuator:
All there are seepage in various degree in oil cylinder in actual applications, oil hydraulic motor etc., and this seepage is uncertain, and the size of seepage is along with the height of system pressure, temperature produces very big variation, and are non-linear.
2, oil pump characteristic:
Any oil pump all has a working zone, be lower than the non-linear increasing of output quantity of this working area oil pump, and the pulsation of oil pump can become very big.This will cause the instability of hydraulic system.
3, actuating motor:
Also there is certain narrow limitation in the stationarity of the actuating motor of producing both at home and abroad when very the slow-speed of revolution moves at present.Then very steady when higher rotation speed.
Summary of the invention
Based on application number be 200710068074.9 in the existing above-mentioned defective of first to file, the objective of the invention is to by above-mentioned application is further improved, provide a kind of flexibility and control accuracy higher, and efficient height, cost low directly drive the hydraulic power supply of oil pump with speed-adjustable motor.
The technological scheme that the present invention takes for achieving the above object is as follows, a kind of high precision hydraulic power source that directly drives oil pump with speed-adjustable motor, comprise actuator, selector valve, fuel tank, servo drive unit, data acquistion and control system, feedback unit, selector valve links to each other with actuator, servo drive unit links to each other with selector valve, data acquistion and control system links to each other with servo drive unit, feedback unit links to each other with data acquistion and control system, actuator links to each other with feedback unit, it is characterized in that: servo drive unit is provided with two groups, parallel connection is on selector valve, one group of servo drive unit is responsible for the oil-feed of control executing mechanism, and another group servo drive unit is responsible for the fuel-displaced of control executing mechanism.
The present invention adopts two groups of servo drive units, one group of servo drive unit of being responsible for the control executing mechanism oil-feed is made up of oil pump, speed-adjustable motor, motor driver, the oil pump filler opening links to each other with fuel tank, the oil pump oil outlet links to each other with the filler opening of selector valve, speed-adjustable motor links to each other with oil pump, motor driver links to each other with speed-adjustable motor, and motor driver links to each other with data acquistion and control system; Being responsible for the fuel-displaced servo drive unit of control executing mechanism for one group is made up of oil pump, speed-adjustable motor, motor driver, the oil pump filler opening links to each other with the filler opening of selector valve, the oil outlet of oil pump links to each other with fuel tank, speed-adjustable motor links to each other with oil pump, motor driver links to each other with speed-adjustable motor, and motor driver links to each other with data acquistion and control system.
Of the present invention further be provided with as follows:
Actuator is preferably oil cylinder or oil hydraulic motor;
Speed-adjustable motor is the motor that actuating motor, variable-frequency motor, stepper motor etc. can be regulated rotating speed by motor driver.
Motor driver is the driver that motor servo driver, frequency variator, controllor for step-by-step motor etc. can be used for regulating motor speed.
Data acquistion and control system is preferably computer or single-chip microcomputer;
Feedback unit is selected from least a of displacement measuring device, force measuring device, be high precision displacement control with displacement measuring device separately, be high-precision force control with force measuring device separately, in the present embodiment, adopt displacement measuring device, force measuring device simultaneously, be high precision displacement, the compound control of power.
The present invention has following beneficial effect:
1, the present invention is according to the actuating mechanism controls target call, the rotating speed of dynamic adjustments speed-adjustable motor, torque, and electricity wasting acc power not, energy-saving effect is remarkable;
2, because two oil pumps of employing come control executing mechanism, an oil-feed, an oil return can realize the power to actuator, the High Accuracy Control of displacement by the speed discrepancy of two oil pumps of dynamic accent;
3, the present invention is simple in structure, and cost of production is low, and is applied widely, is easy to realize the mass production manufacturing.
The invention will be further described below in conjunction with the drawings and specific embodiments.
Description of drawings
Fig. 1 structural representation of the present invention.
Embodiment
As shown in Figure 1, the high precision hydraulic power source that directly drives oil pump with speed-adjustable motor of the present invention, comprise actuator 1, actuator 1 can adopt oil cylinder or oil hydraulic motor as required, and the oil outlet of selector valve 2 links to each other with actuator 1, and the return opening of selector valve 2 links to each other with fuel tank 6, the filler opening of oil pump 3-1 links to each other with fuel tank 6, the oil outlet of oil pump 3-1 links to each other with the filler opening of selector valve 2, and speed-adjustable motor 4-1 links to each other with oil pump 3-1, and motor driver 5-1 links to each other with speed-adjustable motor 4-1; The filler opening of oil pump 3-2 links to each other with the filler opening of selector valve 2, the oil outlet of oil pump 3-2 links to each other with fuel tank 6, speed-adjustable motor 4-2 links to each other with oil pump 3-2, motor driver 5-2 links to each other with speed-adjustable motor 4-2, the servo drive unit that oil pump 3-1, speed-adjustable motor 4-1, motor driver 5-1, fuel tank 6 are formed is responsible for the oil-feed of control executing mechanism 1, and the servo drive unit that oil pump 3-2, speed-adjustable motor 4-2, motor driver 5-2, fuel tank 6 are formed is responsible for the fuel-displaced of control executing mechanism 1.Motor driver 5-1, motor driver 5-2 links to each other with data acquistion and control system 7 respectively, data acquistion and control system 7 can select to adopt computer or single-chip microcomputer, feedback unit 8 one ends link to each other with data acquistion and control system 7, the other end links to each other with actuator 1, feedback unit 8 can select to adopt displacement measuring device 8-1 as required, force measuring device 8-2, displacement measuring device 8-1, force measuring device 8-2 can adopt simultaneously or adopt separately, be high precision displacement control with displacement measuring device 8-1 separately, be high-precision force control with force measuring device 8-2 separately, in the present embodiment, adopt displacement measuring device 8-1 simultaneously, force measuring device 8-2 is high precision displacement, the compound control of power.
During work, data acquistion and control system 7 is according to the target of actuator 1 and the actual signal of displacement measuring device 8-1, force measuring device 8-2, by computing, to motor driver 5-1, motor driver 5-2 transmission speed, torque instruction, motor driver 5-1 is by rotating speed, the torque of speed-adjustable motor 4-1 control oil pump 3-1, by 2 pairs of actuator's 1 oil-feeds of selector valve, motor driver 5-2 is by rotating speed, the torque of speed-adjustable motor 4-2 control oil pump 3-2, by selector valve to actuator's 1 oil return; Advance and retreat, pressure, the speed of the speed discrepancy decision actuator 1 of oil pump 3-1 and oil pump 3-2.Actuator 1 sends signal to data acquistion and control system 7 in real time by displacement measuring device 8-1, the force measuring device 8-2 that connects thereon, data acquistion and control system 7 in real time by computing to motor driver 5-1 motor driver 5-2 transmission speed, torque instruction, so finish a closed loop control, carry out the needs of real work.
Control principle of the present invention is as follows:
Speed-adjustable motor directly drives oil pump under perfect condition, the rotating speed of speed-adjustable motor, torque, and pressure, the flow required with actuator meet following relation by derivation:
P＝p×Q (1)
Q＝n×q (2)
Can get by formula (1), (2)
P＝p×n×q (3)
Because:
Formula (3) substitution formula (4) is got
P-system power in the formula (W)
P-system pressure (Pa)
Q-flow (m
3/ s)
Tw-torque (Nm)
N-motor speed (r/s)
Q-oil pump capacity (m
3/ r)
According to
In a desirable cover system
Be constant, so the required pressure of the torque of speed-adjustable motor and system is directly proportional.According to Q=n * q, the rotating speed of speed-adjustable motor is directly proportional with the required flow of system as can be known.
Derive thus as long as dynamically adjust torque, the rotating speed of speed-adjustable motor, the required pressure of actuator, flow just can be provided.The basic principle of this control system that Here it is.
The present invention uses and the contrast effect analysis in practice:
According to aforesaid analysis of experiments and theory, the present invention adopts two actuating motors to control the oil inlet and oil return that two oil pumps, two oil pumps are controlled oil cylinder respectively respectively in actual applications, the increase and decrease of the speed discrepancy decision oil cylinder working-pressure by two oil pumps.Adopt this scheme can solve following problem:
1, any oil pump all has a working zone, be lower than the non-linear increasing of output quantity of this working area oil pump, and the pulsation of oil pump can become very big.This will cause the instability of hydraulic system.This is that the structure of oil pump determines.
In aforesaid 500kN, 0.03 grade of superposing type force standard machine, what we adopted is crescent gear pump, and discharge capacity is 1ml/r, is 100 teeth in the gear pump, and under perfect condition, the minimum fuel-displaced scale division value of a gear pump is 1ml/100=0.01ml like this; According to table one data, at the 20kN force-detecting position, mean speed is 3.1r/min, just oil cylinder the fuel feeding of oil pump is required be: 1ml/r*3.1r/min=3.1ml/min and control rate that we adopt is 100HZ (adjusting each second 100 times), be 60*100=6000 time/min, this just requires the minimum calibration of flow to be: 3.1/6000=0.00052ml obviously, is difficult to satisfy this high-precision control requirement with an oil pump.
We adopt two actuating motors to control two oil pumps respectively for this reason, two oil pumps are controlled the oil inlet and oil return of oil cylinder respectively, the discharge capacity that the speed discrepancy of two oil pumps multiply by oil pump equals the fuel delivery of oil pump to oil cylinder, we are decided to be 300r/min with the pump speed of oil return in control, rotating speed at 20kN force-detecting position oil-feed oil pump is 303.1r/min in theory like this, though at this moment two oil pumps are to the fuel delivery or the 3.1ml/min of oil cylinder, but the rotating speed of oil pump is 300r/min in this state, minimum calibration behind two oil pump flow superpositions is: 3.1/100/300=0.00001ml, so just can satisfy the requirement of the minimum calibration 0.00052ml of flow fully.
2, owing to two actuating motors move in 300r/min left and right sides speed, can be very steady.
3, owing to an oil pump is arranged in the control oil return, oil cylinder is after taking with the processing of methods such as seal ring, its seepage is far smaller than the speed of oil pump oil return, and this seepage can solve by the end that falls of oil pump oil return speed, so just has been equivalent to make an environment that seepage is constant relatively.
To sum up, adopting two actuating motors to control the oil inlet and oil return that two oil pumps, two oil pumps control oil cylinder respectively respectively can solve: (1) requires flow segmentation with hydraulic power supply according to control, improves resolution; (2) actuating motor, oil pump are moved in desirable working zone; (3) the uncertain seepage of oil cylinder is controlled to constant relatively seepage.
Again test after adopting this scheme, obtained above expected effect (seeing table 2 for details).
Table 2 is the mean value after 50 tests of the two oil pumps of two actuating motor controls
| Force-detecting position (kN) | Power value wave range (kN) | Oil-feed actuating motor rotating speed (r/min) | Oil return actuating motor rotating speed (r/min) | Two actuating motor speed discrepancies (r/min) | Power value overshoot (kN) | The force value stabilization time (s) |
| 20 | 19.999-20.000 | 301.5 | 299 | 3.5 | 0 | 7 |
| 50 | 49.999-50.000 | 304.2 | 295 | 9.2 | 0 | 6 |
| 100 | 99.999-100.000 | 310.1 | 290 | 20.1 | 0 | 6 |
| 200 | 199.999-200.004 | 321.4 | 280 | 41.4 | 0 | 6 |
| 300 | 299.998-300.000 | 335.3 | 270 | 65.3 | 0 | 5 |
| 500 | 499.998-500.000 | 358.2 | 250 | 108.2 | 0 | 5 |
Claims (9)
1. high precision hydraulic power source that directly drives oil pump with speed-adjustable motor, comprise actuator (1), selector valve (2), servo drive unit, fuel tank (6), data acquistion and control system (7), feedback unit (8), selector valve (2) links to each other with actuator (1), servo drive unit links to each other with selector valve (2), data acquistion and control system (7) links to each other with servo drive unit, feedback unit (8) links to each other with data acquistion and control system (7), actuator (1) links to each other with feedback unit (8), it is characterized in that: servo drive unit is provided with two groups, one group of servo drive unit is responsible for the oil-feed of control executing mechanism (1), another group servo drive unit is responsible for the fuel-displaced of control executing mechanism (1), wherein, one group of servo drive unit being responsible for control executing mechanism (1) oil-feed is by first oil pump (3-1), first speed-adjustable motor (4-1), first motor driver (5-1) is formed, the filler opening of first oil pump (3-1) links to each other with fuel tank (6), first speed-adjustable motor (4-1) links to each other with first oil pump (3-1), and first motor driver (5-1) links to each other with first speed-adjustable motor (4-1); Be responsible for one group of fuel-displaced servo drive unit of control executing mechanism (1) by second oil pump (3-2), second speed-adjustable motor (4-2), second motor driver (5-2) is formed, the oil outlet of second oil pump (3-2) links to each other with fuel tank (6), second speed-adjustable motor (4-2) links to each other with second oil pump (3-2), second motor driver (5-2) links to each other with second speed-adjustable motor (4-2), the oil outlet of first oil pump (3-1) be connected on the selector valve (2) first motor driver (5-1) after the filler opening of second oil pump (3-2) links to each other, second motor driver (5-2) links to each other with data acquistion and control system (7) respectively.
2. as claimed in claim 1ly a kind ofly directly drive the high precision hydraulic power source of oil pump with speed-adjustable motor, it is characterized in that: actuator (1) is oil cylinder or oil hydraulic motor.
3. as claimed in claim 1ly a kind ofly directly drive the high precision hydraulic power source of oil pump with speed-adjustable motor, it is characterized in that: first speed-adjustable motor (4-1) is selected from any one of actuating motor, variable-frequency motor, stepper motor.
4. as claimed in claim 1ly a kind ofly directly drive the high precision hydraulic power source of oil pump with speed-adjustable motor, it is characterized in that: second speed-adjustable motor (4-2) is selected from any one of actuating motor, variable-frequency motor, stepper motor.
5. as claimed in claim 1ly a kind ofly directly drive the high precision hydraulic power source of oil pump with speed-adjustable motor, it is characterized in that: first motor driver (5-1) is selected from any one of motor servo driver, frequency variator, controllor for step-by-step motor.
6. as claimed in claim 1ly a kind ofly directly drive the high precision hydraulic power source of oil pump with speed-adjustable motor, it is characterized in that: second motor driver (5-2) is selected from any one of motor servo driver, frequency variator, controllor for step-by-step motor.
7. as claimed in claim 1ly a kind ofly directly drive the high precision hydraulic power source of oil pump with speed-adjustable motor, it is characterized in that: data acquistion and control system (7) is computer or single-chip microcomputer.
8. as claimed in claim 1ly a kind ofly directly drive the high precision hydraulic power source of oil pump with speed-adjustable motor, it is characterized in that: feedback unit (8) is at least a for displacement measuring device (8-1), force measuring device (8-2).
9. as claimed in claim 8ly a kind ofly directly drive the high precision hydraulic power source of oil pump with speed-adjustable motor, it is characterized in that: feedback unit (8) adopts displacement measuring device (8-1), force measuring device (8-2) simultaneously.
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| CN2008101216915A CN101392769B (en) | 2008-10-17 | 2008-10-17 | High precision hydraulic power source for directly driving oil pump by speed governing generator |
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| CN2008101216915A CN101392769B (en) | 2008-10-17 | 2008-10-17 | High precision hydraulic power source for directly driving oil pump by speed governing generator |
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| CN101793275B (en) * | 2010-03-30 | 2015-01-07 | 宁波安信数控技术有限公司 | High-precision hydraulic servo control system |
| CN101968067A (en) * | 2010-10-24 | 2011-02-09 | 绍兴市肯特机械电子有限公司 | High precision pump control system |
| CN102562720B (en) * | 2011-12-30 | 2016-08-17 | 万国强 | A kind of intelligent hydraulic power source of the output power that entirely coincide with loads change |
| CN103075390A (en) * | 2013-02-05 | 2013-05-01 | 焦作市华科液压机械制造有限公司 | Digital hydraulic power pack |
| CN105422521B (en) * | 2015-12-16 | 2017-05-10 | 桂林星辰科技股份有限公司 | Hydraulic linear drive system based on control of servo pumps, and control method |
| CN106500992B (en) * | 2016-09-21 | 2018-10-09 | 北京精密机电控制设备研究所 | A kind of drainage engine kerosene servo mechanism ground experiment method |
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