CN1140859C - Composite speed regulating system and method with frequency conversion and electrohydraulic proportion technology - Google Patents

Composite speed regulating system and method with frequency conversion and electrohydraulic proportion technology Download PDF

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Publication number
CN1140859C
CN1140859C CNB011265264A CN01126526A CN1140859C CN 1140859 C CN1140859 C CN 1140859C CN B011265264 A CNB011265264 A CN B011265264A CN 01126526 A CN01126526 A CN 01126526A CN 1140859 C CN1140859 C CN 1140859C
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valve
unit
hydraulic
cylinder
signal
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CN1332397A (en
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翁振涛
凌俊杰
方曙光
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Ningbo Chap Machinery Manufacture Co., Ltd.
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Ningbo Hoyea Machinery Manufacture Co Ltd
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Abstract

The present invention relates to a composite speed regulating system and a method with a frequency conversion and electrohydraulic proportion technology. The present invention has a control principle that a position sensor (12) drives a relay return circuit, voltage signals which are converted are transmitted to a computer unit, and then, the computer unit sends out a current signal I1 transmitted to an electrohydraulic proportion overflow valve (5), causing the overflow valve to have a corresponding valve port opening. The computer unit sends out the other current signal I2 transmitted to a frequency converter (1), and the frequency converter (1) outputs the corresponding frequency to an electric motor (2) which drives a power pump (3). Simultaneously, the current signal I2 is transmitted to an electrohydraulic proportion throttle valve (4), causing the throttle valve (4) to have corresponding resistance; flow provided by the power pump (3) flows to a reversing valve (6) through the overflow of the overflow valve (5) and the resistance of the throttle valve (4), the flow enter a left chamber or a right chamber of an oil cylinder (7) from a reversing valve (6) to push a piston (14) to carry out a reciprocating rectilinear movement, and thereby, the production process is completed. The present invention not only saves energy consumption, but also make a system to have good control performance.

Description

Frequency conversion and electrohydraulic proportion technology composite speed regulating system and method
Technical field
The present invention is used in the hydraulic system, and by a kind of governing system and the method that electric-hydraulic proportion throttle grverning and frequency control combine, its realization makes hydraulic system reduce energy consumption most possibly, makes hydraulic system have good control ability simultaneously.
Background technology
At present, in many hydraulic systems, great majority are used in the electric-hydraulic proportion throttle grverning system and are adorned a ratio pressure---flow valve, during speed governing, unnecessary flow passing ratio pressure valve overflow.The advantage of this speed governing is that response speed is fast, adjusting is flexible, convenient, cost is low, but, owing to exist spill losses and difference pressuring loss, in speed governing and pressure regulation process, be accompanied by bigger energy loss (unexpectedly up to about 50%), cause the temperature rising of system, the serviceable life of reducing Hydraulic Elements and working fluid thus.
Shortcoming for better explanation the method now illustrates in conjunction with Fig. 7 and Fig. 8.Among Fig. 7, power pump 3 is driven by motor 2, and the oil of discharging some enters a left side or the right chamber of big cylinder 7 through proportional throttle valve 4 and reversal valve 6, promotes big cylinder 7 and moves to the left or to the right.What of fuel delivery the speed of big cylinder 7 depend on.Press working condition requirement, the motion of big cylinder 7 is by starting--quicken--maximal rate--decelerations---stop to form, in the different motion process of big cylinder 7, the pressure difference of cylinder 7 greatly, flow is also difference.Under this different requirement, the proportion electro-magnet 41 of control system control throttling valve 4, the resistance of adjusting throttling valve 4 makes it by working condition requirement corresponding resistance be arranged.The proportion electro-magnet 51 of the surplus valve 5 of control system control simultaneously, the opening degree of adjusting surplus valve 5 makes unnecessary oil flow back to fuel tank 8, regulates the operating rate of big cylinder 7 thus.In above-mentioned simple as can be seen electro-hydraulic proportional throttle valve speed regulation process, produce two kinds of energy losses, flow through the spill losses of surplus valve 5 dischargings and the difference pressuring loss that throttling valve 4 produces.
For this energy loss is described, now illustrate with Fig. 8: Q is the fuel delivery of power pump 3, OA is the flow of big cylinder 7 when steadily quickening, flow when Q1 is big cylinder 7 maximal raties, shade among the figure is spill losses, S1 is the position that big cylinder 7 beginnings are steadily slowed down, and S2 is that big cylinder 7 stops to the site.When big cylinder 7 during from starting point O to steady acceleration, the proportion electro-magnet 41 of control system control throttling valve 4 slowly diminishes the resistance of throttling valve 4, and the oil that flows to big cylinder 7 is more.Regulate the proportion electro-magnet 51 of surplus valve 5 simultaneously, the opening degree that makes surplus valve 5 from large to small, i.e. spill losses is from large to small.When the motion of big cylinder 7 maximal raties, i.e. AB section, at this moment, it is less that the resistance of throttling valve 4 is transferred, and it is less that the opening degree of surplus valve 5 is also transferred, and energy loss is also minimum.When 7 beginnings of big cylinder steadily decelerate to when stopping to put in place, regulate the resistance of throttling valve 4, make resistance slowly become big again, the opening degree of surplus valve 5 changes from small to big simultaneously, and oil spilling is more, and flow loss is increasing.
Above-mentioned is energy loss on the big cylinder 7, and this method is used on the little cylinder 10, and the loss of energy is bigger, see Fig. 9, OA is that little cylinder 10 is quickened required oil masses fast, and Q1 is little cylinder 10 required flow at the uniform velocity the time, and BC is little cylinder 10 required energy when slowing down fast.In actual production, the fuel delivery of power pump 3 is supplied with by big cylinder 7 required flows, and the fuel delivery of power pump 3 is far longer than the required flow of little cylinder 10.When little cylinder 10 begins Fast starting, control system is regulated the proportion electro-magnet 41 of electro-hydraulic proportional throttle valve 4, the resistance that makes throttling valve 4 is by very big extremely smaller, control system is regulated the proportion electro-magnet 51 of electricity liquid ratio relief valve 5 simultaneously, the opening degree that makes spill valve 5 is also by very big extremely smaller, make a large amount of oil flow back to fuel tank 8, and flow to the flow of little cylinder 10 shown in OA by the reversal valve 9 of little cylinder by spill valve 5.When little cylinder uniform motion, control system is regulated the proportion electro-magnet 41 of electro-hydraulic proportional throttle valve 4 and the proportion electro-magnet 51 of surplus valve 5, makes the opening degree of the resistance of throttling valve 4 and surplus valve 5 constant, makes the flow that flows to little cylinder 10 shown in AB.When the quick stop of little cylinder 10, the opening degree of the resistance of throttling valve 4 and spill valve 5 again by smaller to very big, the oil that flows to little cylinder 10 is reduced suddenly, little cylinder 10 is stopped fast, to reach working condition requirement.This shows that simple electric-hydraulic proportion throttle grverning energy loss is very high.
At present, for energy efficient, another kind of speed regulating method is frequency control in hydraulic system, and it is a rotating speed of regulating motor by the line frequency that changes motor, the rotating speed of oil pump is changed, reach the purpose of regulating flow with the fuel delivery that changes oil pump.The advantage of this speed governing is almost not have energy loss, but its shortcoming is because the moment of inertia of motor is bigger, response speed is very slow, and acceleration and deceleration characteristic are relatively poor, and simple frequency Varying and speed changing method can't be suitable for those acceleration or the working condition requirement of deceleration characteristic fast fast.
For the shortcoming of this method is described, now see also Figure 10,1 is frequency converter among the figure, and 2 is motor, and 3 is power pump, the 8th, fuel tank, 6 are big-movement cylinder reversal valve, 7 is big cylinder.Computerized control system 11 is transformed into an electric signal by working condition requirement, the input end of input converter 1 after control system is handled, the output of the output terminal of frequency converter 1 different frequency control the rotating speed of motor 2, motor 2 drives power pumps 3, makes the fuel delivery of power pump 3 just equal the flow of working condition requirement, and this part flow enters a left side or the right chamber of big cylinder 7 by reversal valve 6, this shows, in the frequency conversion speed-adjusting system, both do not had spill losses, do not had the pressure loss yet.
Now consult Figure 11 and describe its process in detail, curve OA is that big cylinder 7 is started flow required when extremely steadily accelerating to maximal rate, curve A B is that big cylinder 7 is decelerated to flow required when stopping to put in place, when big cylinder 7 is started to maximal rate, the output frequency of frequency converter 1 increases gradually, accelerate the rotating speed of motor 2, make of the requirement of the fuel delivery of power pump 3, do not have energy loss this moment by curve OA.When big cylinder 7 beginning S1 steadily be decelerated to working condition requirement stop to site S2 the time, frequency converter 1 reduces output frequency gradually, change the rotating speed of motor 2, the fuel delivery of power pump 3 is reduced, but because motor 2 is systems of a big inertia, when requiring big cylinder 7 to stop to put in place, power pump 3 still has oil mass output because of the inertia of motor 2, make big cylinder 7 still have bigger movement velocity, just can stop to put in place during to the B point, flow is along the AB curvilinear motion, prolong the working time like this, reduced work efficiency, do not met the requirement that working condition requirement stops to put in place at the S2 point again, though, do not meet above-mentioned working condition requirement so simple frequency control utilization factor on energy is very high.
Above-mentioned is the shortcoming of this method when being used for big cylinder 7, and it is less or when working quick, frequent little cylinder 10, if come speed governing with frequency converter merely, because the inertia of motor 2 is very big, response speed is slow, can't realize this working condition requirement at all to be used for energy.
Summary of the invention
Technical matters solved by the invention is: frequency Varying and speed changing method and electric-hydraulic proportion throttle grverning method are combined, and purpose is the control that the shortcoming that overcomes above-mentioned two kinds of methods realizes the required flow of hydraulic system.
The present invention solves the problems of the technologies described above the technical scheme that is adopted: the present invention adds frequency control in the system of existing electric-hydraulic proportion throttle grverning, it included by cylinder being used to of being connected with cylinder controls the dynamically working unit that the reversal valve of the direction of motion of cylinder piston is formed, comprise the combination valve unit of forming by electricity liquid ratio relief valve and electro-hydraulic proportional throttle valve, and the power cell that includes motor and power pump composition, their threes' connection is to be connected with the combination valve unit between dynamically working unit and the power cell, it is characterized in that: described composite speed regulating system includes the converter unit of controlling motor speed, described composite speed regulating system also includes the computer unit of controlling governing system, the converter unit of power controlling unit is controlled by computer unit, and the position sensor unit that the cylinder piston position signal is provided for computer.
The power input of the frequency converter in the described converter unit is connected to power frequency supply, and its output terminal is connected to the motor in the power cell.Motor is controlled by frequency converter, its output shaft links to each other with power pump, the oil inlet pipe of power pump links to each other with fuel tank, the oil-in of the electro-hydraulic proportional throttle valve in the flowline of power pump and the combination valve unit and the oil-in of electricity liquid ratio relief valve link to each other, the oil inlet pipe of the reversal valve in the flowline of electro-hydraulic proportional throttle valve and the dynamically working unit links to each other, and the flowline of reversal valve links to each other with the chamber, the left and right sides of cylinder.The feature of its control loop is: the position sensor unit that is controlled by the piston motion in the cylinder is sent position signalling, position signalling is transformed into electric signal by relay circuit, be passed to computer unit, behind the voltage signal that program controller in the described computer unit or special purpose computer obtain being transmitted by position transducer, immediately two data D that are stored in inner certain zone 1And D 2Access, calculate actual needed pressure and flow, calculate and carry out as follows by the percentage of system pressure and flow:
P=D 1
Q=Q max×D 2/100
Calculate the marking current value by pressure and flow value:
I 1=I 01+(I max-I 01)(P max-P)/(P max-P min)
I 2=I 02+(I max-I 02)Q/Q max
Wherein: P, P Max, P MinRepresent actual, the highest, minimum pressure in the hydraulic system respectively;
Q, Q MaxRepresent actual, maximum flow in the hydraulic system respectively;
I 01, I 02The initial current of representing surplus valve, throttling valve respectively;
I MaxBe the maximum current in the hydraulic system;
D 1, D 2Be the corresponding a pair of data of each operating mode, pressure and flow in the corresponding hydraulic system of difference, (having in the internal memory much to data) be current signal I wherein 1Cause the proportion electro-magnet coil of electricity liquid ratio relief valve, the proportion electro-magnet coil is subjected to have certain thrust behind this signal, the pressure set points that is system is certain, when the oil-out pressure of electro-hydraulic proportional throttle valve is higher than this setting value, pressure affacts the left end of the pilot stage in the surplus valve by the left end control oil channel of electricity liquid ratio relief valve, the oil-in pressure of electro-hydraulic proportional throttle valve affacts the right-hand member of the pilot stage in the surplus valve by the right-hand member control oil channel of electricity liquid ratio relief valve, after holding pressure reduction and electromagnet thrust relatively about pilot stage, the main valve plug of surplus valve is opened, made the oil at throttling valve inlet place flow back to fuel tank by surplus valve.Another current signal I that program controller or special purpose computer send 2Cause the proportion electro-magnet coil of electro-hydraulic proportional throttle valve, regulate the opening degree of the spool of electro-hydraulic proportional throttle valve, make it to produce corresponding flow resistance.Current signal I 2Cause the signal input part of the frequency converter in the converter unit simultaneously, frequency converter is according to current signal I 2, output control signal KI after the internal signal analysis 2, motor is at this signal KI 2Following drive power pump, the rotating speed that makes power pump is the value of calculating as follows:
n=(n max-n max)KI 2/(I max-I min)
Wherein: n Max, n MinRepresent real maximum, the minimum rotating speed of motor in the hydraulic system respectively;
I Max, I MinRepresent the maximum of system, minimum electric current respectively;
K is that the correction factor of frequency converter also changes the fuel delivery of power pump with signal, to satisfy the requirement of operating mode.The flow that power pump provides is through flowing to the reversal valve of cylinder behind the throttling valve, the magnet coil of reversal valve is controlled by program controller or special purpose computer, when the right-hand member magnet coil of reversal valve is subjected to signal, promotes spool, make ↑ ↓ spool works, and the piston that promotes in the cylinder moves right.When the left end magnet coil of reversal valve is subjected to signal, promote spool, make Spool works, and promotes the interior piston of cylinder to left movement.The linear reciprocating motion of piston, thus the processing of product finished.
Compared with prior art, the invention has the advantages that: the invention enables energy consumption to descend, and it is fast still to make hydraulic system have response speed, regulates flexibly, good control ability easily, also reduced the noise of machine, improved working environment.
Description of drawings
The present invention can be used for all dynamic properties and has certain requirements and make in the bigger electrohydraulic control system of the power of the energy of electric energy, as injection machine, oil press, die casting machine, machine tooling equipment dispatch control system, executive component is more in these systems, generally has 3~4 cylinder at least.Can be divided into two classes from their work characteristics and power consumption situation, a class is that power drain is bigger, the big cylinder that impulse stroke or time are long.Another kind of is to consume less or quick, the frequent little cylinder of working of energy.For advantage of the present invention is described better, now respectively select a representativeness and accompanying drawing to be illustrated.
Fig. 1. the embodiment of speed regulating method of the present invention (is example with little, big cylinder)
Fig. 2. be the synoptic diagram of control system of the present invention:
Fig. 3. the energy diagram of the present invention on big cylinder;
Fig. 4. the energy diagram of the present invention on little cylinder;
Fig. 5. the double pump embodiment of the present invention in the bigger hydraulic system of power
Fig. 6. the many pump embodiment of the present invention in the bigger hydraulic system of power
Fig. 7. merely with the embodiment (correlation technique) of electric-hydraulic proportion throttle grverning on big cylinder
Fig. 8. the energy diagram during merely with the electric-hydraulic proportion throttle grverning on big cylinder; (correlation technique)
Fig. 9. the energy diagram during merely with the electric-hydraulic proportion throttle grverning on little cylinder; (correlation technique)
Figure 10. merely with the embodiment of frequency control on big cylinder; (correlation technique)
Figure 11. the energy diagram during merely with frequency control on big cylinder; (correlation technique)
Embodiment
Embodiment describes in further detail the present invention below in conjunction with accompanying drawing.
Fig. 1 is speed governing embodiment of the present invention, between power frequency supply and motor 2, be connected with frequency converter 1, motor 2 output shafts link to each other with power pump 3, the oil inlet pipe of power pump 3 links to each other with fuel tank 8, the flowline of power pump 3 links to each other with the oil-in of electro-hydraulic proportional throttle valve 4 and the oil-in of electricity liquid ratio relief valve 5, the oil-out of surplus valve 5 links to each other with fuel tank 8, and the oil-out of electro-hydraulic proportional throttle valve 4 communicates with the reversal valve 6 of big or small cylinder 7 and 10 and 9 oil-in, the oil-out of the reversal valve 6 of big cylinder 7 joins with big cylinder 7, and the oil-out of the reversal valve 9 of little cylinder 10 links to each other with little cylinder 10.Its control principle (see figure 2) is: the piston position sensor 12 of cylinder sends position signalling, after this signal is transformed into voltage signal by relay circuit, be passed to a terminal of the input interface of the program controller of control system or special purpose computer 11, after program controller or special purpose computer 11 obtain this signal, immediately two data D that are stored in inner certain zone 1And D 2Access, calculate actual needed pressure and flow, calculate and carry out as follows by the percentage of system pressure and flow:
P=D 1
Q=Q max×D 2/100
Calculate the marking current value by pressure and flow value:
I 1=I 01+(I max-I 01)(P max-P)/(P max-P min)
I 2=I 02+(I max-I 02)Q/Q max
Wherein: P, P Max, P MinRepresent actual, the highest, minimum pressure in the hydraulic system respectively;
Q, Q MaxRepresent actual, maximum flow in the hydraulic system respectively;
I 01, I 02The initial current of representing surplus valve, throttling valve respectively;
I MaxBe the maximum current in the hydraulic system
D 1, D 2Be the corresponding a pair of data of each operating mode, pressure and flow in the corresponding hydraulic system of difference, (having in the internal memory much to data) is the appointment terminal output of two-way current signal by the output interface of program controller or special purpose computer 11, I 1Cause the magnet coil 51 of electricity liquid ratio relief valve 5, make the thrust of electromagnet of electricity liquid ratio relief valve 5 certain, the pressure set points that is system is certain, when the oil-out pressure of electro-hydraulic proportional throttle valve 4 is higher than this setting value, pressure affacts the left end of the pilot stage 52 in the surplus valve 5 by the left end control oil channel 13 of electricity liquid ratio relief valve 5, the oil-in pressure of electro-hydraulic proportional throttle valve 4 affacts the right-hand member of the pilot stage 52 in the surplus valve 5 by the right-hand member control oil channel 15 of electricity liquid ratio relief valve 5, after holding pressure reduction and electromagnet thrust relatively about pilot stage, the main valve plug of surplus valve 5 is opened, made the oil of throttling valve 4 porch flow back to fuel tank 8 by surplus valve 5.And current signal 1 2Cause the magnet coil 41 of electro-hydraulic proportional throttle valve 4, when this signal changes, the thrust of the electromagnet of throttling valve 4 changes thereupon, by 41 effects of the pilot stage in the throttling valve 4, the valve core opening of throttling valve 4 is also changed thereupon, the flow that flows through throttling valve 4 is also different thereupon, to reach the requirement of operating mode.This current signal 1 2Cause simultaneously and hand over the signal input part of device 1 frequently, frequency converter is according to current signal I 2, output control signal KI after the internal signal analysis 2, motor is at this signal KI 2Following drive power pump, the rotating speed that makes power pump is the value of calculating as follows:
n=(n max-n min)KI 2/(I max-I min)
Wherein: n Max, n MinRepresent real maximum, the minimum rotating speed of motor in the hydraulic system respectively;
I Max, I MinRepresent the maximum of system, minimum electric current respectively;
K is that the correction factor motor 2 of frequency converter drives power pump 3, the fuel delivery of power pump 3 is also changed thereupon, to satisfy the requirement of operating mode.The flow that power pump 3 provides is through flowing to the reversal valve 6 of cylinder 7 behind the throttling valve 4, the magnet coil of reversal valve 6 is controlled by program controller or special purpose computer, when the right-hand member magnet coil 61 of reversal valve 6 is subjected to signal, promote spool, make ↑ ↓ spool works, and the pistons 14 that promote in the cylinder 7 move right.When the left end magnet coil 62 of reversal valve 6 is subjected to signal, promote spool, the ↘ spool is worked, the piston 14 in the promotion cylinder 7 is to left movement.The linear reciprocating motion of piston, thus the processing of product finished.
When big cylinder 7 was started to maximal rate by working condition requirement, position transducer was transformed into a voltage signal by operating mode, after program controller or special purpose computer 11 calculation process, and current signal I 2The input end of input converter 1, frequency converter 1 output terminal output correspondent frequency then, the rotating speed of control motor 2, motor 2 drives power pumps 3, makes the fuel delivery of power pump 3 equal the required oil mass of big cylinder 7, current signal I simultaneously 2Pass to the proportion electro-magnet coil 41 of throttling valve 4, make throttling valve 4 inoperative, promptly flow does not have resistance by throttling valve 4 time, directly enters a left side or the right chamber of big cylinder 7 by reversal valve 6.When the big cylinder 7 of working condition requirement is decelerated to when stopping to put in place, program controller or special purpose computer 11 control system are subjected to after the voltage signal that sensor sends, by the I that signals after the calculation process 2Give frequency converter 1 and electro-hydraulic proportional throttle valve 4, this moment, frequency converter 1 was subjected to behind the signal by internal analysis, reduce output frequency, reduce the rotating speed of motor 2, the power pump 3 corresponding fuel deliveries that reduced, meanwhile, throttling valve 4 increases resistances, and surplus valve 5 is subjected to the current signal I that program controller or special purpose computer 11 transmit 1Increase opening degree, strengthen spillway discharge, the flow that flows to reversal valve 6 is reduced suddenly, flow flows into big cylinder 7 by reversal valve 6, makes big cylinder 7 stop to put in place by working condition requirement.
When little cylinder 10 is pressed the working condition requirement motion, program controller or special purpose computer 11 control of conversion devices 1, making frequency converter 1 output frequency is a constant control motor 2, make the running speed of motor 2 constant, power pump 3 is worked as fixed displacement pump, the fuel delivery of power pump 3 is a bit larger tham the flow maximal value of working condition requirement, and in quick deceleration and quick accelerator, the proportion electro-magnet 41 of program controller or special purpose computer 11 control electro-hydraulic proportional throttle valves 4 and the proportion electro-magnet 51 of surplus valve 5, regulate the resistance of throttling valve 4 and the opening degree of surplus valve 5, make unnecessary flow flow back to fuel tank 8, with this requirement that reaches quick acceleration and slow down fast by surplus valve 5.
For flow situation of the present invention is described better.Now consult Fig. 4, this is the energy diagram of the present invention on big cylinder, curve OA is big cylinder 7 required oil mass of big cylinder 7 when starting to maximal rate, curve A DB is the fuel delivery that big cylinder 7 is decelerated to power pump 3 when stopping to put in place, broken line ACDE is the big cylinder 7 actual required flow when stopping to put in place that slows down, and S2 is stopping to the site of big cylinder 7.When big cylinder 7 is started to maximal rate, behind frequency converter 1 suspension control signal, output frequency increases the rotating speed of accelerating motor 2 gradually, and motor 2 drives power pump 3, make the fuel delivery of power pump 3 equal the flow OA of big cylinder 7 required usefulness, this moment, electro-hydraulic proportional throttle valve 4 was inoperative.When big cylinder 7 moves to the A point, when reducing speed now by operating mode, program controller or special purpose computer 11 are subjected to output current signal I behind the position sensor signal 2The proportion electro-magnet coil 41 of control system control of conversion device 1 and electro-hydraulic proportional throttle valve 4, make the fuel feeding of power pump 3 begin to reduce, simultaneously, ratio throttle grverning method is devoted oneself to work, unnecessary oil is flowed back to fuel tank 8 by surplus valve 5, the flow that flows to reversal valve 6 is changed by broken line ACDE, guarantee that big cylinder 7 can stop at the S2 point.Shade among the figure is the spill losses of flowing through surplus valve 5.This shows that speed regulating method of the present invention has improved the high shortcoming of throttle grverning energy consumption significantly, can increase economic benefit greatly, satisfied the control characteristic requirement of operating mode again.
See also Fig. 5, this is that the present invention is used in the energy diagram on the little cylinder, and OA is that little cylinder 10 is quickened required oil masses, and AB is little cylinder 10 required flow at the uniform velocity the time, and BC is little cylinder 10 required energy when slowing down.Program controller or special purpose computer 11 control of conversion devices 1, making frequency converter 1 output frequency is a constant control motor 2, make the running speed of motor 2 constant, power pump 3 is worked as fixed displacement pump, the fuel delivery Q of power pump 3 is a bit larger tham the flow maximal value Q1 of working condition requirement, and in quick deceleration and quick accelerator, the proportion electro-magnet 41 of program controller or special purpose computer 11 control electro-hydraulic proportional throttle valves 4 and the proportion electro-magnet 51 of surplus valve 5, regulate the resistance of throttling valve 4 and the opening degree of surplus valve 5, make unnecessary flow flow back to fuel tank 8, reach good control performance and energy-saving effect with this by surplus valve 5.
Below be the present invention at the embodiment that is used for the bigger hydraulic system of power: one. double pump system, as Fig. 6.
The required flow of operating mode between 300 liters/minute~400 liters/minute, in the hydraulic system with two power pumps.The present invention is compound, and speed regulating method is: two power pump discharge capacities are identical, and one with common electric machine 16, and another is with variable-frequency motor 2.
When the big cylinder 7 of working condition requirement is worked, the power supply power supply of common electric machine 16 usefulness 50HZ, it drives power pump 3, makes the fuel delivery of power pump 3 all enter a left side or the right chamber of big cylinder 7 by retaining valve 18, reversal valve 6.And the fuel delivery of the variation that requires flow in the operating mode by program controller or special purpose computer control system 11 and frequency converter 1, variable-frequency motor 2, power pump 3 through the coordination of electro-hydraulic proportional throttle valve 4, electricity liquid ratio relief valve 5 in conjunction with realizing.
When the little cylinder 11 of working condition requirement is worked, the required flow of little cylinder is less, this moment, control system was controlled surplus valve 17 and retaining valve 18, retaining valve 18 is closed, surplus valve 17 is opened, the oil that flexible driven by motor power pump is provided is all by surplus valve 17 overflows, and this pump is kept attitude, is in unloading condition.And the flow that the required flow of low-power pump provides by the frequency conversion unit is realized through the coordinative role of electro-hydraulic proportional throttle valve 4, electricity liquid ratio relief valve 5.
Hence one can see that, and the range of adjustment by this semi-fluid amount covers whole system operation, both can be energy-conservation, reach good control performance again.Two. multiple pump
The required fuel delivery of operating mode is more than 400 liters/minute, and hydraulic system is with three pumps or multiple pump, and existing is example with the three pump system, as Fig. 7.The throughput ratio of three pumps is 1: 1: 3, and wherein a little pump 3 is driven by frequency control motor 2, and range of adjustment is 1/4 of a total flow, is combined into three pump system with other two power pumps 3 and 21.
When the big cylinder 7 of working condition requirement was worked, the power supply power supply of common electric machine 19 and 20 usefulness 50HZ drove power pump 21 and 3 respectively, made the fuel delivery of power pump 21 and 3 all enter a left side or the right chamber of big cylinder 7 by retaining valve 18, reversal valve 6.And the fuel delivery of the variation that requires flow in the operating mode by program controller or special purpose computer 11 control system and frequency converter 1, variable-frequency motor 2, power pump 3 through the coordination of electric-hydraulic proportion pressure valve 4, electricity liquid ratio relief valve 5 in conjunction with realizing.
When the little cylinder 10 of working condition requirement is worked, the required flow of little cylinder is less, control system control this moment surplus valve 17, retaining valve 18, make closed check valve, surplus valve is opened, and oil pump 21 and 3 fuel feeding are all by surplus valve 17 overflows, and this two pump 21 and 3 is kept attitude, be in unloading condition, and the flow that the required flow of little oil pump provides by the frequency conversion unit is realized through the coordinative role of electro-hydraulic proportional throttle valve 4, electricity liquid ratio relief valve 5.As seen, the combination with 1/4 adjustable total flow and other two pumps can cover system-wide job requirement.
From the above, in hydraulic system, the governing system and the method that adopt electric-hydraulic proportion throttle grverning and frequency control to combine are not only regulated flexibly, and convenient, response speed is fast, and has reduced energy consumption most possibly, is a kind of far-reaching invention that has.

Claims (10)

1. frequency conversion and electric-hydraulic proportion composite speed regulating system, it included by cylinder (7) being used to of being connected with cylinder (7) controls the dynamically working unit that the reversal valve (6) of the direction of motion of cylinder (7) piston (14) is formed, comprise the combination valve unit of forming by electricity liquid ratio relief valve (5) and electro-hydraulic proportional throttle valve (4) and include the power cell that motor (2) and power pump (3) are formed, their threes' connection is to be connected with the combination valve unit between dynamically working unit and the power cell, it is characterized in that: described composite speed regulating system includes the converter unit of control motor (2) rotating speed, described composite speed regulating system also includes the computer unit of controlling governing system, the converter unit of power controlling unit is controlled by computer unit, and the position sensor unit that cylinder (7) piston (14) position signalling is provided for computer (11).
2. frequency conversion as claimed in claim 1 and electric-hydraulic proportion composite speed regulating system is characterized in that the power input of the frequency converter (1) in the described converter unit is connected to power frequency supply, and its output terminal is connected to the motor (2) in the power cell.
3. frequency conversion as claimed in claim 1 and electric-hydraulic proportion composite speed regulating system, it is characterized in that motor (2) in the described power cell is controlled by the frequency converter (1) in the frequency converter unit, its output shaft links to each other with power pump (3), the oil inlet pipe of the power pump in the described power cell (3) links to each other with fuel tank (8), and the flowline of power pump (3) links to each other with the combination valve unit.
4. frequency conversion as claimed in claim 1 and electric-hydraulic proportion composite speed regulating system, it is characterized in that the oil-in of the electro-hydraulic proportional throttle valve (4) in the described combination valve unit and the oil-in of electricity liquid ratio relief valve (5) link to each other with the flowline of power pump (3), one end of the right-hand member control oil pipe (15) in the described electricity liquid ratio relief valve (5) communicates with the oil inlet pipe of surplus valve (5), the other end communicates with the right-hand member of the pilot valve (52) of surplus valve (5), one end of the left end control oil pipe (13) of surplus valve (5) links to each other with the flowline of throttling valve (4), the other end communicates with the left end of the pilot valve (52) of surplus valve (5), and the flowline of described throttling valve (5) links to each other with the dynamically working unit.
5. frequency conversion as claimed in claim 1 and electric-hydraulic proportion composite speed regulating system, the flowline of the electro-hydraulic proportional throttle valve (4) in the oil inlet pipe that it is characterized in that the reversal valve (6) in the described dynamically working unit and the combination valve unit links to each other, and the flowline of reversal valve (6) links to each other with the chamber, the left and right sides of cylinder (7).
6. frequency conversion and the compound speed regulating method of electric-hydraulic proportion, it is characterized in that: the position sensor unit that is controlled by piston (14) motion in the cylinder (7) is sent position signalling, position signalling is transformed into electric signal by relay circuit, be passed to computer unit, after computer unit obtains this electric signal, through two signals of signal Processing output, wherein a signal is transferred to the electricity liquid ratio relief valve (5) in the combination valve unit of being made up of electricity liquid ratio relief valve (5) and electro-hydraulic proportional throttle valve (4), regulating system pressure; Another signal of computer unit output reaches the electro-hydraulic proportional throttle valve (4) in the combination valve unit, the flow of control system, this signal passes to converter unit simultaneously, after converter unit is handled by analysis, output signal to the power cell of forming by motor (2) and power pump (3), corresponding flow is provided after power cell is controlled, this flow flows into dynamically working unit through combination valve unit, and the reversal valve (6) of that described dynamically working unit is connected with cylinder (7) by cylinder (7), as to be used to control cylinder (7) piston (14) direction of motion is formed; The computer unit signal that also generates electricity is simultaneously given the right-hand member magnet coil (61) and the left end magnet coil (62) of the reversal valve (6) in the dynamically working unit, regulate the flow that flows into the dynamically working unit and enter the chamber, the left and right sides of the cylinder (7) of dynamically working unit, close the operating mode that symbol requires thereby finish cylinder (7).
7. frequency conversion as claimed in claim 6 and the compound speed regulating method of electric-hydraulic proportion, it is characterized in that voltage signal that the program controller of described computer unit or special purpose computer (11) must transmit by position transducer after, immediately two data D that are stored in inner certain zone 1And D 2Access, calculate actual needed pressure and flow, calculate and carry out as follows by the percentage of system pressure and flow:
P=D 1
Q=Q max×D 2/100
Calculate the marking current value by pressure and flow value:
I 1=I 01+(I max-I 01)(P max-P)/(P max-P min)
I 2=I 02+(I max-I 02)Q/Q max
Wherein: P, P Max, P MinRepresent actual, the highest, minimum pressure in the hydraulic system respectively;
Q, Q MaxRepresent actual, maximum flow in the hydraulic system respectively;
I 01, I 02The initial current of representing surplus valve, throttling valve respectively;
I MaxBe the maximum current in the hydraulic system;
D 1, D 2Be the corresponding a pair of data of each operating mode, respectively pressure and the flow in the corresponding hydraulic system.
8. frequency conversion as claimed in claim 7 and the compound speed regulating method of electric-hydraulic proportion is characterized in that described current signal I 1Cause the proportion electro-magnet coil (51) of electricity liquid ratio relief valve (5), proportion electro-magnet coil (51) is subjected to this signal I 1After have certain thrust, the flow pressure of system and this thrust are moved in the main valve plug of electricity liquid ratio relief valve (5) after relatively.
9. frequency conversion as claimed in claim 7 and the compound speed regulating method of electric-hydraulic proportion is characterized in that described current signal I 2Cause the proportion electro-magnet coil (41) of electro-hydraulic proportional throttle valve (4), regulate the opening degree of the spool of electro-hydraulic proportional throttle valve (4), make it to produce corresponding flow resistance.
10. frequency conversion as claimed in claim 7 and the compound speed regulating method of electric-hydraulic proportion is characterized in that described current signal I 2Cause the signal input part of the frequency converter (1) in the converter unit simultaneously, frequency converter (1) is according to current signal I 2, output control signal KI after the internal signal analysis 2, motor (2) is at this signal KI 2Following drive power pump (3) makes the rotating speed of power pump (3) reach the value that calculates as follows:
n=(n max-n min)KI 2/(I max-I min)
Wherein: n Max, n MinRepresent actual maximum, the minimum rotating speed of motor in the hydraulic system respectively;
I Max, I MinRepresent the maximum of system, minimum electric current respectively;
K is the correction factor of frequency converter.
CNB011265264A 2001-08-22 2001-08-22 Composite speed regulating system and method with frequency conversion and electrohydraulic proportion technology Expired - Fee Related CN1140859C (en)

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DE102004052602B4 (en) * 2004-10-29 2008-03-27 Sauer-Danfoss Aps valve assembly
CN102179912B (en) * 2011-04-15 2014-11-05 联塑(杭州)机械有限公司 Frequency-conversion energy-saving stable actuation improvement method and system of injection molding machine
JP5486633B2 (en) * 2012-04-17 2014-05-07 住友ゴム工業株式会社 Tire vulcanizer hydraulic system
CN102689427B (en) * 2012-06-15 2014-12-10 成都市团结模具制造厂 Energy-saving control system of injection molding machine and operating mode of energy-saving control system
CN103277306B (en) * 2013-05-09 2015-10-14 恒天九五重工有限公司 A kind of power frequency supply that uses is as the multifunctional drill of power
CN104775953B (en) * 2015-04-10 2017-03-08 河北工程大学 A kind of multichannel energy-saving fuel feed system
CN105508320B (en) * 2016-02-24 2017-06-16 益阳新华美机电科技有限公司 Two parallel pumps hydraulic pressure converter plant and rubber mixing machine drum driven system

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