CN1410682A - Hydraulic system composed of hydraulic bus and switch hydraulic source - Google Patents

Abstract

Several switchable hydraulic power sources, which are connected to own control valve and actuator, are installed between the oil supply way and the oil gallery of the hydraumatic bus. The switchable hydraulic power source includes the element for sensing the hydraulic pressure, high-speed switch valve, the one way valve, the element for the hydraulic volume. Based on different functions, the lifting pressure type or the pressure reduction and increasing flow type of the switchable hydraulic power source can be obtained through combining these hydraulic power source so as to provide the functions that the traditional hydraulic system can not supply. Each actuator can obtain suitable needed pressure and flux form the final output. The industrialization of the invention will promote the development of the energy saving hydraulic system.

Description

The hydraulic system that constitutes by hydraulic bus and switch hydraulic source

Technical field

The present invention relates to pressurized machine or hydrodynamic pressure transducer.

Background technique

One of advantage of hydraulic system maximum is its multi executors characteristic, promptly can drive the action of multichannel final controlling element simultaneously by single oil hydraulic pump fuel feeding.

The production line hydraulic system of enterprises such as present most of industrial and mineral, metallurgy, iron and steel all adopts the fuel system of hydraulic bus: export one road pressure oil pipe, one tunnel control oil, one tunnel oil return and one tunnel leakage oil by pumping plant, all hydraulic actuator control units all hang on this hydraulic bus.Because the charge oil pressure on the hydraulic bus is constant, thereby require the load of each final controlling element and charge oil pressure to adapt, perhaps need again final controlling element to be suspended on the hydraulic bus with this final controlling element load by a reduction valve (be reduced to adapt the charge oil pressure on the hydraulic bus).Owing to can't realize boosting and decompression and flow increasing, the physical dimension of ubiquity pumping plant delivery pressure height, each final controlling element is subjected to problems such as restriction loss is big on the restriction of final controlling element charge oil pressure, the reduction valve.

The hydraulic system of large-scale engineering machinery also adopts single oil pump feed to drive the mode of a plurality of final controlling element coordinations mostly.Though can realize that the delivery pressure of pump and highest load pressure adapt by modes such as load-sensitives, but same existence can't realize boosting and the problem of decompression and flow increasing, thereby for non-highest load pressure connection performer, restriction loss on control valve is still very big, and energy dissipation is serious.

Summary of the invention

The objective of the invention is to design a kind of hydraulic system that constitutes by hydraulic bus and switch hydraulic source, directly hang over the input end in switch source on the hydraulic bus, boosted or decompression and flow increasing pressure and flow that final output and each final controlling element demand adapt by the speed-sensitive switch mode.

The technical solution used in the present invention is as follows:

It comprises hydraulic bus, several control valves, and several final controlling element is characterized in that: between the fuel feeding road P1 of hydraulic bus and oil circuit T several switch hydraulic sources are housed, it is connected with separately control valve, final controlling element.

Working procedure: hydraulic power unit is fixed value (10MPa) to the pressure of hydraulic bus output, and power can be complementary with the needed total output of each performer.The input end of each switch hydraulic source directly hangs on the hydraulic bus, and by the adjusting of high-speed switch valve (one of key element in the switch hydraulic source) dutycycle being realized closed loop control to its delivery pressure, delivery pressure reduced or be elevated to the required force value of final controlling element, for final controlling element provide with its consumed power (be not flow! ) flow that adapts, reach optimum energy-saving effect.

Switch hydraulic source is the booster type switch hydraulic source, it comprises liquid inductance element, high-speed switch valve, one-way valve, element for the hydraulic volume, the input end of liquid inductance element and the output terminal of high-speed switch valve are connected across respectively between the fuel feeding road P1 and oil circuit T of hydraulic bus, the output terminal that is contained in the liquid inductance element on the fuel feeding road P1 of hydraulic bus connects the input end of high-speed switch valve and the input end of one-way valve respectively, the output terminal of one-way valve is connected on the output circuit P2, and the two ends of element for the hydraulic volume are connected across respectively between output circuit P2 and oil circuit T;

Switch hydraulic source is a decompression and flow increasing type switch hydraulic source, it comprises liquid inductance element, high-speed switch valve, one-way valve, element for the hydraulic volume, the input end of high-speed switch valve and one-way valve is connected across respectively between the fuel feeding road P1 and oil circuit T of hydraulic bus, the output terminal that is contained in the high-speed switch valve on the fuel feeding road P1 of hydraulic bus connects the input end of liquid inductance element and the output terminal of one-way valve respectively, and the output terminal of liquid inductance element is connected on output circuit P2 and connects.The two ends of element for the hydraulic volume are connected across respectively between output circuit P2 and oil circuit T.

Element for the hydraulic volume just can be used as the element for the hydraulic volume in the switch hydraulic source as long as the pressure reduction at its two ends is similar to the described relation of following formula with flow by this element, represents with following formula: $Q_4=C\frac{d\left({\mathrm{\Δp}}_2\right)}{\mathrm{dt}}$

Wherein: Q ₄-flow by element for the hydraulic volume

C-liquid appearance value, dimension is [(L/min)/MPa] S

The variance ratio of-element for the hydraulic volume two ends pressure reduction

Having the element for the hydraulic volume that is similar to the described relation of following formula is accumulator, spring hydraulic cylinder.Liquid inductance element just can be used as the sensing element in the switch hydraulic source as long as be similar to the described relation of following formula by the flow of this element and the pressure reduction at its two ends, represents with following formula: $\mathrm{\Δp}=L\frac{{\mathrm{dQ}}_1}{\mathrm{dt}}$

In the formula: the pressure reduction at Δ p-liquid inductance element two ends

L-liquid inductance value, dimension is [MPa/ (L/min)] S;

-the variance ratio of flow by liquid inductance element

Has the liquid inductance element that is similar to the described relation of following formula for by the oil hydraulic motor of a high-speed hydraulic motor with a big inertia load of forming with the flywheel that hydraulic motor output shaft directly links to each other of driving.

The new principle hydraulic system that is made of hydraulic bus and switch hydraulic source has overcome that conventional hydraulic can't realize boosting and the problem of decompression and flow increasing, is a kind of energy-saving hydraulic system of brand-new principle.The industrialization of this hydraulic system can greatly promote the development of energy-saving hydraulic system.

Description of drawings

Fig. 1 is a structured flowchart of the present invention;

Fig. 2 is a booster type switch hydraulic source structure principle chart;

Fig. 3 is a decompression and flow increasing type switch hydraulic source structure principle chart;

Fig. 4 is the thermal accumulator of using as element for the hydraulic volume in switch hydraulic source;

Fig. 5 is the spring hydraulic cylinder of using as element for the hydraulic volume in switch hydraulic source;

Fig. 6 is the oil hydraulic motor of the big inertia load of driving used as liquid inductance element in switch hydraulic source.

Embodiment

As shown in Figure 1, between the fuel feeding road P1 of hydraulic bus and oil circuit T several switch hydraulic sources are housed, it is connected with separately control valve, final controlling element.

According to the difference of switch hydraulic source function, can be divided into two kinds of booster type switch hydraulic source and decompression and flow increasing type switch hydraulic sources: 1. booster type switch hydraulic source

Technological scheme: the booster type switch hydraulic source is made up of liquid inductance element, high-speed switch valve, one-way valve and element for the hydraulic volume, its structure as shown in Figure 2:

P among the figure ₁The charge oil pressure of expression hydraulic bus, T shows the return pressure of hydraulic bus;

p ₂The delivery pressure of expression switch hydraulic source, because it is again simultaneously the pressure that liquid holds two ends, thereby this pressure can not suddenly change;

Q ₁The flow of liquid inductance element is flow through in expression, and this flow can not suddenly change;

p ₃The pressure of expression liquid inductance output terminal, this pressure switches constantly between high output pressure and return pressure and switches along with the high speed of high-speed switch valve.

Q ₃The flow of high-speed switch valve is flow through in expression, and this flow is also along with the high speed of high-speed switch valve is switched constantly at Q ₁And switch between zero.

Q ₂And Q ₄Represent the output flow of switch hydraulic source respectively and flow through the flow that liquid holds, flow these two flows and equal to flow through liquid inductance when high-speed switch valve cuts off equals zero when high-speed switch valve is connected.

If the quality of the internal leakage of element for the hydraulic volume and liquid inductance element, friction and element for the hydraulic volume can be ignored, and suppose that high-speed switch valve and one-way valve are ideal element (restriction loss of opening-closing process is zero), be T the pulsewidth modulation period of wave of high-speed switch valve, dutycycle (current"on"time with cycle ratio) is D, then the delivery pressure p of switch hydraulic source ₂Be directly proportional with the incoming pressure of hydraulic bus, be inversely proportional to, the input flow rate Q of hydraulic bus with dutycycle ₁Be directly proportional with the output flow of system, be inversely proportional to dutycycle.That is: $p_2=\frac{p_1}{D}$ $Q_1=\frac{Q_2}{D}$

Thereby realize boosting of switch hydraulic source.Simultaneously, delivery pressure p ₂The fluctuation amplitude be directly proportional with output flow, the appearance value C that holds with liquid is inversely proportional to, and is directly proportional wave period with pulsewidth modulation, is directly proportional with the dutycycle of electromagnet power-off time.That is: $p_{2\max }-p_{2\min }=\frac{Q_2}{C}(1-D)T$

As long as high-speed switch valve and one-way valve dynamic performance approach desirable high-speed switch valve and one-way valve, the pressure conversion efficiency of switch hydraulic source can reach 100%, and promptly output power equals input power, and realization the harmless of hydraulic system boosted.

Working procedure: for high-speed switch valve provides the cycle is T, and dutycycle (current"on"time with cycle ratio) is the pulse width modulated wave of D.When high-speed switch valve cut off the power supply (oil circuit is logical), the output terminal of liquid inductance element led to oil return, and liquid inductance quickens under the effect of hydraulic bus charge oil pressure, stored energy; When high-speed switch valve was switched on (oil circuit is disconnected), to the final controlling element fuel feeding, because delivery pressure is higher than the charge oil pressure of hydraulic bus, liquid inductance slowed down under the effect of hydraulic bus backpressure difference the output terminal of liquid inductance element, discharges stored energy by one-way valve; Thereby realize boosting of switch hydraulic source.Element for the hydraulic volume is used for carrying out filtering, reduces the delivery pressure ripple that causes because of speed-sensitive switch.

Can export required force value by to the control of pulse width modulated wave dutycycle by above-mentioned oil circuit, and for final controlling element provide with its consumed power (be not flow! ) flow that adapts, reach optimum energy-saving effect.2. decompression and flow increasing type switch hydraulic source

Technological scheme: decompression and flow increasing type switch hydraulic source is made up of liquid inductance element, high-speed switch valve, one-way valve and element for the hydraulic volume, its structure as shown in Figure 3:

P among the figure ₁The charge oil pressure of expression hydraulic bus, T shows the return pressure of hydraulic bus;

p ₂The delivery pressure of expression switch hydraulic source, because it is again simultaneously the pressure that liquid holds two ends, thereby this pressure can not suddenly change;

Q ₁The flow of liquid inductance element is flow through in expression, and this flow can not suddenly change;

p ₃The pressure of expression liquid inductance input end, this pressure is along with the high speed switching of high-speed switch valve is constantly switched between hydraulic bus charge oil pressure and return pressure.

Q ₃The flow of high-speed switch valve is flow through in expression, and this flow is also along with the high speed of high-speed switch valve is switched constantly at Q ₁And switch between zero.

Q ₂And Q ₄Represent the output flow of switch hydraulic source respectively and flow through the flow that liquid holds, flow these two flows and that equal to flow through liquid inductance.

If the quality of the internal leakage of element for the hydraulic volume and liquid inductance element, friction and element for the hydraulic volume can be ignored, and suppose that high-speed switch valve and one-way valve are ideal element (restriction loss of opening-closing process is zero), be T the pulsewidth modulation period of wave of high-speed switch valve, dutycycle (current"on"time with cycle ratio) is D, then the delivery pressure p of switch hydraulic source ₂Be directly proportional with the incoming pressure of hydraulic bus, be directly proportional, the average input flow rate Q of hydraulic bus with the dutycycle of power-off time ₃Be directly proportional with the output flow of system, be directly proportional with the dutycycle of power-off time.That is:

p ₂＝(1-D)P ₁

Q ₃＝(1-D)Q ₂

Thereby realize the decompression and flow increasing of switch hydraulic source.Simultaneously, delivery pressure p ₂The fluctuation amplitude be directly proportional with the fluctuation of output flow, the appearance value C that holds with liquid is inversely proportional to, and is directly proportional wave period with pulsewidth modulation, is directly proportional with the dutycycle of electromagnet current"on"time, that is: $p_{2\max }-p_{2\min }\≈\frac{Q_1-Q_2}{C}\mathrm{DT}$

As long as high-speed switch valve and one-way valve dynamic performance approach desirable high-speed switch valve and one-way valve, the pressure conversion efficiency of switch hydraulic source can reach 100%, and promptly output power equals input power, realizes the harmless step-down of hydraulic system.

Working procedure: for high-speed switch valve provides the cycle is T, and dutycycle (current"on"time with cycle ratio) is the pulse width modulated wave of D.When high-speed switch valve cuts off the power supply (oil circuit is logical), the charge oil pressure of the logical hydraulic bus of the input end of liquid inductance element, liquid inductance quickens under the effect of hydraulic bus charge oil pressure, stored energy; When high-speed switch valve was switched on (oil circuit is disconnected), the input end of liquid inductance element was by one-way valve oil suction from return line, because delivery pressure is higher than the charge oil pressure of hydraulic bus, liquid inductance slows down under the effect of backpressure difference, discharges stored energy; Thereby realize the step-down of switch hydraulic source.Element for the hydraulic volume is used for carrying out filtering, reduces the delivery pressure ripple that causes because of speed-sensitive switch.

Can export required force value by to the control of pulse width modulated wave dutycycle by above-mentioned oil circuit, and for final controlling element provide with its consumed power (be not flow! ) flow that adapts, reach optimum energy-saving effect.

No matter be the booster type switch hydraulic source, or decompression and flow increasing type switch hydraulic source, all be unable to do without liquid inductance and liquid and hold two critical elements.The hydraulic element that can be used as the use of liquid inductance and liquid appearance in switch hydraulic source need have following characteristics: 1. liquid holds

Technological scheme: for hydraulic element with pressure pulsation absorptivity, as long as the pressure reduction at its two ends is similar to the described relation of following formula with flow by this element, just can be used as the element for the hydraulic volume in the switch hydraulic source, its liquid appearance value represents with C, and dimension is [(L/min)/Mpa] s. $Q_4=C\frac{d\left({\mathrm{\Δp}}_2\right)}{\mathrm{dt}}$

Have the element for the hydraulic volume that is similar to the described relation of following formula accumulator, spring hydraulic cylinder or the like are arranged, they can directly be purchased from accumulator or stream cylinder pressure manufacturer.

1) accumulator

Accumulator structure commonly used is basic identical in the structure of the accumulator that can use as element for the hydraulic volume in switch hydraulic source and the present hydraulic system, is example with the bladder accumulator, and its structure as shown in Figure 4.

P among the figure ₀The preliminary filling pressure of expression accumulator, V ₀The original volume of representing this accumulator air bag;

p ₂In the expression pipeline during instantaneous pressure, and think that the two ends pressure reduction of accumulator is exactly p ₂

Q ₄For flowing through the flow of accumulator.

Because the change procedure of nitrogen pressure is an approximate adiabatic process in the air bag, so the pressure reduction at its two ends has following relation with flow by this accumulator: $Q_4=\frac{1}{1.4}{\left(\frac{p_0}{p_2}\right)}^{\frac{1}{1.4}}\frac{1}{p_2}\frac{{\mathrm{dp}}_2}{\mathrm{dt}}$ This accumulator can hold use as liquid in switch hydraulic source, its liquid appearance value is: $C=\frac{1}{1.4}{\left(\frac{p_0}{p_2}\right)}^{\frac{1}{1.4}}\frac{1}{p_2}$

2) spring hydraulic cylinder

The spring hydraulic cylinder that can use as element for the hydraulic volume in switch hydraulic source is made up of cylinder body, low friction-piston and spring, and its structure as shown in Figure 5.

Among the figure, K shows the elasticity coefficient of spring, and A and m represent the hyperbaric chamber area and the quality of low friction-piston respectively, and f represents the friction ractor between piston and the cylinder body;

p ₂Represent the pressure at spring cylinder two ends respectively with T;

Q ₄The flow of spring cylinder is flow through in expression, and x represents the displacement of spring cylinder piston;

C _ImThe internal leakage coefficient of expression cylinder.

If ignore spring cylinder piston mass m, f and internal leakage C rub _Im, and control spring is in the elastic range forever, then the pressure reduction at its two ends has following relation with flow by this spring cylinder: $Q_4=\frac{A^2}{k}\frac{{\mathrm{dp}}_2}{\mathrm{dt}}$ This spring cylinder can hold use as liquid in switch hydraulic source, its liquid appearance value is: $C=\frac{A^2}{k}$ Working procedure: the working procedure when using as element for the hydraulic volume in switch hydraulic source with accumulator and spring hydraulic cylinder is example:

1) accumulator

The gasbag pressure of accumulator is charged to about 1/2 of the highest average delivery pressure in advance, its entry end is directly received in the pressure piping that needs the absorption pressure pulsation, oil circuit does not connect.This accumulator just can be used as element for the hydraulic volume and use in switch hydraulic source.When the pressure in the pressure piping surpassed middle pressure, the air bag volume of accumulator reduced, and the absorption portion flow reduces the flow in the pressure piping, and pressure descends; When the pressure in the pressure piping was lower than middle pressure, the air bag volume of accumulator increased, and the release portion flow increases the flow in the pressure piping, and pressure raises.Thereby reduced the pressure ripple in the switch hydraulic source effectively.

2) spring hydraulic cylinder

The two ends of spring hydraulic cylinder are received respectively on the pressure piping and oil circuit that needs the absorption pressure pulsation.This spring hydraulic cylinder just can be used as element for the hydraulic volume and use in switch hydraulic source.When the pressure difference of pressure piping and oil circuit surpasses average differential pressure, move on the piston, absorption portion flow from pressure piping reduces the flow in the pressure piping, and pressure descends; When the pressure difference of pressure piping and oil circuit was lower than average differential pressure, piston moved down, and to pressure piping release portion flow, the flow in the pressure piping was increased, and pressure raises.Thereby reduced the pressure ripple in the switch hydraulic source effectively.2. liquid inductance technological scheme: for hydraulic element with inertia load, as long as be similar to the described relation of following formula by the flow of this element and the pressure reduction at its two ends, just can be used as the liquid inductance element in the switch hydraulic source, its liquid inductance value represents that with L dimension is [Mpa/ (Lmin)] s. $\mathrm{\Δp}=L\frac{{\mathrm{dQ}}_1}{\mathrm{dt}}$

Having one of liquid inductance element of being similar to the described relation of following formula is the oil hydraulic motor that drives big inertia load.The oil hydraulic motor of the big inertia load of driving that can use as liquid inductance element in switch hydraulic source is made up of with the flywheel that hydraulic motor output shaft directly links to each other with one a high-speed hydraulic motor, can directly purchase from oil hydraulic motor manufacturer.Its structure as shown in Figure 6.

Among the figure, J represents total rotary inertia of oil hydraulic motor rotating part and flywheel, and D represents the discharge capacity of oil hydraulic motor; B represents the angle friction ractor of oil hydraulic motor;

p ₁With p ₂The pressure of representing these hydraulic element two ends respectively;

Q ₁The flow of oil hydraulic motor is flow through in expression, and ω shows the angular velocity of oil hydraulic motor;

C _ImThe internal leakage coefficient of expression motor.If ignore the friction B of oil hydraulic motor and leak C _Im, then flowing through the flow of this motor and the pressure reduction at its two ends has following relation: $p_1-p_2=\frac{J}{D^2}\frac{{\mathrm{dQ}}_1}{\mathrm{dt}}$ This oil hydraulic motor can use as liquid inductance in switch hydraulic source, and its liquid inductance value is: $L=\frac{J}{D^2}$ Working procedure: the working procedure when still using as liquid inductance element in switch hydraulic source with the oil hydraulic motor that drives big inertia load is example:

Oil hydraulic motor is connected in series to need guarantees that flow can not suddenly change, and in the pressure piping that can store fast, release energy.This oil hydraulic motor just can be used as liquid inductance element and use in switch hydraulic source.When the pressure of inlet side surpassed outlet side, the big inertia body (flywheel) that oil hydraulic motor drove will quicken, and the flow by this oil hydraulic motor can not be suddenlyd change, and stores energy in the big inertia body (flywheel); When the pressure of inlet side was lower than outlet side, the big inertia body (flywheel) that oil hydraulic motor drove will slow down, and the flow by this oil hydraulic motor can not be suddenlyd change, and discharged the energy that is stored in the big inertia body (flywheel).Thereby guaranteed the continuity of switch hydraulic source output flow.

Claims (5)

1. the hydraulic system that constitutes by hydraulic bus and switch hydraulic source, it comprises hydraulic bus, several control valves, several final controlling element, it is characterized in that: between the fuel feeding road P1 of hydraulic bus and oil circuit T several switch hydraulic sources are housed, it is connected with separately control valve, final controlling element.

2. the hydraulic system that constitutes by hydraulic bus and switch hydraulic source according to claim 1, it is characterized in that: switch hydraulic source is the booster type switch hydraulic source, it comprises liquid inductance element [1], high-speed switch valve [2], one-way valve [3], element for the hydraulic volume [4], the output terminal of the input end of liquid inductance element [1] and high-speed switch valve [2] is connected across respectively between the fuel feeding road P1 and oil circuit T of hydraulic bus, the output terminal that is contained in the liquid inductance element [1] on the fuel feeding road P1 of hydraulic bus connects the input end of high-speed switch valve [2] and the input end of one-way valve [3] respectively, the output terminal of one-way valve [3] is connected on the output circuit P2, and the two ends of element for the hydraulic volume [4] are connected across respectively between output circuit P2 and oil circuit T;

3. the hydraulic system that constitutes by hydraulic bus and switch hydraulic source according to claim 1, it is characterized in that: switch hydraulic source is a decompression and flow increasing type switch hydraulic source, it comprises liquid inductance element [1], high-speed switch valve [2], one-way valve [3], element for the hydraulic volume [4], the input end of high-speed switch valve [2] and one-way valve [3] is connected across respectively between the fuel feeding road P1 and oil circuit T of hydraulic bus, the output terminal that is contained in the high-speed switch valve [2] on the fuel feeding road P1 of hydraulic bus connects the input end of liquid inductance element [1] and the output terminal of one-way valve [3] respectively, and the output terminal of liquid inductance element [1] is connected on the output circuit P2.The two ends of element for the hydraulic volume [4] are connected across respectively between output circuit P2 and oil circuit T.

4. according to claim 2 or the 3 described hydraulic systems that constitute by hydraulic bus and switch hydraulic source, it is characterized in that: said element for the hydraulic volume [4] is as long as the pressure reduction at its two ends is similar to the described relation of following formula with flow by this element, just can be used as the element for the hydraulic volume in the switch hydraulic source, represent with following formula: $Q_4=C\frac{d\left({\mathrm{\Δp}}_2\right)}{\mathrm{dt}}$ Wherein: Q ₄-flow by element for the hydraulic volume

C-liquid appearance value, dimension is [(L/min)/MPa] S

The variance ratio of-element for the hydraulic volume two ends pressure reduction

Having the element for the hydraulic volume that is similar to the described relation of following formula is accumulator, spring hydraulic cylinder.

5. according to claim 2 or the 3 described hydraulic systems that constitute by hydraulic bus and switch hydraulic source, it is characterized in that: said liquid inductance element [1] is as long as be similar to the described relation of following formula by the flow of this element and the pressure reduction at its two ends, just can be used as the sensing element in the switch hydraulic source, represent with following formula: $\mathrm{\Δp}=L\frac{{\mathrm{dQ}}_1}{\mathrm{dt}}$

In the formula: the pressure reduction at Δ p-liquid inductance element two ends

L-liquid inductance value, dimension is [MPa/ (L/min)] S;

-the variance ratio of flow by liquid inductance element

Has the liquid inductance element that is similar to the described relation of following formula for by the oil hydraulic motor of a high-speed hydraulic motor with a big inertia load of forming with the flywheel that hydraulic motor output shaft directly links to each other of driving.

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