Background technique
Current, hydraulic system is widely used in every field; But because hydraulic system is passed through the hydraulic oil transferring power, the return oil pressure that oil return circuit forms can reduce the execution movement speed of hydraulic actuator; Generally speaking, the return line of transmission hydraulic oil is long more, and return oil pressure is big more, and the speed that hydraulic actuator is carried out predetermined action is more little.
Current, in the engineering machinery technology, often need to utilize hydraulic system to drive hydraulic actuator far away again and carry out predetermined actions; The return line of transmission hydraulic oil is also just long, and in general, when return line surpassed 20 meters, return oil pressure can reduce the execution movement speed of hydraulic actuator very significantly, and then influences the operating characteristics of hydraulic system.
At present, known field solves the excessive problem of return oil pressure in order to following scheme usually.
A kind of scheme is the caliber that increases the oil return oil pipe; This scheme can make hydraulic oil flow moving more smooth and easy really, thereby reduces return oil pressure relatively, improves the execution movement speed of hydraulic actuator.But but have a lot of problems in practical work process: at first, the caliber that strengthens the oil return oil pipe then must increase the cost of hydraulic system.Secondly, strengthen the caliber of oil return oil pipe, can increase the weight of hydraulic pipe line, and then cause more problems, in movement process, strengthened the amplitude of fluctuation of machinery or vehicle, finally reduce the stability of complete machine such as weight increase meeting because weight is excessive; Weight increases the wearing and tearing that can aggravate hydraulic oil pipe, or the like.Once more, the caliber of hydraulic oil pipe increases, and also can cause the inconvenience of operation; When the oil return oil pipe need be wrapped on the suitable pulley, will inevitably need radial and axial larger-size pulley, take bigger space; The hydraulic oil pipe bend ratio of big caliber is difficulty, and then causes the difficulty of site operation.In a word, this scheme because the hydraulic oil pipe of hydraulic system is changed, has therefore increased the making maintenance cost of hydraulic system in the execution movement speed that improves hydraulic actuator, also increased the control difficulty of hydraulic system.
Another kind of scheme is the system pressure that increases hydraulic system.As everyone knows, under the constant situation of the caliber of hydraulic oil pipe, can realize the purpose of speedup, thereby, improve the execution movement speed of hydraulic actuator by increasing pressure reduction by boost pressure.For hydraulic system, pressure increases, and just need have higher requirement to the sealability of each parts, and this will greatly increase the cost of hydraulic system again; Simultaneously, higher system pressure can make the very fast rising of hydraulic fluid temperature, and then influences the performance of hydraulic oil, influences the stability of hydraulic system.Therefore, this technological scheme has increased the cost of hydraulic system in the execution movement speed that improves hydraulic actuator, reduced the stability of hydraulic system.
In a word, technique scheme attempts to solve by the mode of hydraulic system being carried out bigger transformation the problem of hydraulic system return oil pressure, though can reduce the return oil pressure of hydraulic pipe line, improve the execution movement speed of hydraulic actuator, but have the deficiency that cost is too high, reduce the stability of hydraulic system.
Summary of the invention
Be directed to this, first purpose of the present invention is that providing a kind of can reduce the hydraulic system of return oil pressure with less cost.
Second purpose of the present invention is, a kind of operating method of hydraulic system is provided, to reduce the return oil pressure of hydraulic system.
In order to realize first purpose of the present invention, the hydraulic system that provides comprises hydraulic actuator, the hydraulic pressure cavity of described hydraulic actuator links to each other with the oil supplying device of hydraulic system by the main oil pipe road, comprise also and inhale the element of draining the oil that the described suction suction of the element oil pocket of draining the oil of draining the oil communicates by auxiliary piping with the hydraulic pressure cavity of hydraulic actuator; The described suction element of draining the oil depends on a drive mechanism volume of inhaling the oil pocket of draining the oil is changed, with the hydraulic oil of at least a portion in the low-pressure cavity of sucking-off hydraulic actuator.
Preferably, the described suction element of draining the oil depends on described drive mechanism, and the drain the oil hydraulic oil of oil pocket of suction is entered in the hyperbaric chamber of hydraulic actuator.
Preferably, the described suction oil pocket of draining the oil comprises that first inhales the oil pocket and second of draining the oil and inhale the oil pocket of draining the oil, described hydraulic pressure cavity comprises first hydraulic pressure cavity and second hydraulic pressure cavity, described auxiliary piping comprises first auxiliary piping and second auxiliary piping, described first inhales the oil pocket of draining the oil communicates by described first auxiliary piping with first hydraulic pressure cavity, and described second inhales the oil pocket of draining the oil communicates by described second auxiliary piping with second hydraulic pressure cavity; Described second change direction and first of inhaling the oil pocket volume of draining the oil is inhaled changing in the opposite direction of the oil pocket volume of draining the oil.
Preferably, also be connected with series flow control valve in the described auxiliary piping, with the size of the passage section of regulating described auxiliary piping.
Preferably, described hydraulic system also comprises control gear, carries out predetermined actions so that inhale the element of draining the oil according to the action of hydraulic actuator.
Preferably, described control gear comprises the interlock contactor; The described suction element of draining the oil is driven by a hydraulic drive mechanism, and described hydraulic drive mechanism and hydraulic actuator are respectively by electromagnetic valve; Described solenoid valve is controlled by described interlock contactor, to realize the interlock of described hydraulic drive mechanism and hydraulic actuator.
Preferably, also be connected with solenoid valve in the described auxiliary piping, with the break-make of control auxiliary piping; This solenoid valve is controlled by described interlock contactor, sucks and when discharging hydraulic oil, keeps auxiliary piping for logical with the element of draining the oil in suction.
Alternatively, the described suction element of draining the oil is the suction of being made up of cylinder body and the piston oil cylinder of draining the oil, and the described suction oil cylinder of draining the oil has position transducer, the generation prearranged signal during to the precalculated position with the piston motion of the oil cylinder of draining the oil in described suction.
Preferably, described position transducer links to each other with the interlock contactor, so that described interlock contactor is according to the action of the SC sigmal control hydraulic drive mechanism of position transducer generation.
In order to realize second purpose of the present invention, the operating method of a kind of hydraulic system that also provides, described hydraulic system comprises hydraulic actuator, to carry out predetermined actions, when described hydraulic actuator is carried out first predetermined action, this method comprises the sucking-off step, with at least a portion hydraulic oil of the low-pressure cavity of the described hydraulic actuator of sucking-off.
Preferably, described first predetermined action and sucking-off step are carried out simultaneously.
Preferably, when described hydraulic actuator is carried out second predetermined action opposite with described first predetermined action, the hydraulic oil of sucking-off is entered in the hyperbaric chamber of hydraulic actuator.
Compared with prior art, hydraulic system provided by the invention also comprises inhales the element of draining the oil, and the described suction suction of the element oil pocket of draining the oil of draining the oil communicates by auxiliary piping with the hydraulic pressure cavity of hydraulic actuator; The described suction element of draining the oil depends on a drive mechanism volume of inhaling the oil pocket of draining the oil is changed, with when hydraulic actuator is carried out predetermined actions, hydraulic oil sucking-off with low-pressure cavity, and then reduce the return oil pressure of hydraulic actuator low-pressure cavity, improve the execution movement speed of hydraulic actuator.Unlike the prior art, technological scheme provided by the invention, the component parts to hydraulic system does not carry out bigger change, adopt the suction element of draining the oil that the mode of the hydraulic oil sucking-off of the low-pressure cavity of hydraulic actuator is reduced its return oil pressure, and then the execution movement speed of raising hydraulic actuator, therefore, the present invention provides a kind of technological scheme that hydraulic actuator is carried out movement speed that improves from a new technical standpoint; Simultaneously, owing to the component parts of hydraulic system is not carried out bigger change, therefore, can keep lower realization cost.
In further technological scheme, element is drained the oil in described suction can also be under described drive mechanism, and the drain the oil hydraulic oil of oil pocket of suction is entered in the hyperbaric chamber of hydraulic actuator; This technological scheme hydraulic oil that element sucks of suction can being drained the oil enters in the hyperbaric chamber of hydraulic actuator, thereby it is the suction hydraulic oil that element sucks of draining the oil is recycling, when reducing return oil pressure, can make full use of the energy of the hydraulic oil of suction, so promptly can reduce return oil pressure, can save energy again, improve the working efficiency of hydraulic system.
In further technological scheme, the described suction oil pocket of draining the oil comprises that first inhales the oil pocket and second of draining the oil and inhale the oil pocket of draining the oil, described hydraulic pressure cavity comprises first hydraulic pressure cavity and second hydraulic pressure cavity, described auxiliary piping comprises first auxiliary piping and second auxiliary piping, described first inhales the oil pocket of draining the oil communicates by described first auxiliary piping with first hydraulic pressure cavity, and described second inhales the oil pocket of draining the oil communicates by described second auxiliary piping with second hydraulic pressure cavity; Described second inhales drain the oil oil pocket volume and first suction oil pocket volume of draining the oil changes synchronously, and changes in the opposite direction.This technological scheme can alleviate the return oil pressure of corresponding low-pressure cavity when hydraulic actuator is carried out the action of both direction; Can on two operative orientations of hydraulic actuator, improve the execution movement speed of hydraulic actuator on the one hand; On the other hand, change synchronously because second inhales drain the oil oil pocket volume and first suction oil pocket volume of draining the oil, and change in the opposite direction, can be in the hydraulic oil of sucking-off hydraulic actuator low-pressure cavity, replenish hydraulic oil to the hyperbaric chamber of hydraulic actuator, therefore, can also further accelerate the speed that hydraulic actuator is carried out action.
In further technological scheme, in auxiliary piping, also be connected with series flow control valve, with the passage section of control auxiliary piping.This technological scheme can be adjusted the size of auxiliary piping passage section by series flow control valve, the element action meets predetermined requirement so that hydraulic actuator and suction are drained the oil, make hydraulic actuator and inhale the element action of draining the oil to have synchronism or have other relevance, carry out the stability of action to keep hydraulic actuator.
In further technological scheme, also comprise control gear, carry out predetermined actions so that inhale the element of draining the oil according to the action of hydraulic actuator, thereby make the control of hydraulic system more simple.
In further technological scheme, described control gear comprises the interlock contactor; The described suction element of draining the oil is driven by a hydraulic drive mechanism, described hydraulic drive mechanism and hydraulic actuator can be respectively by electromagnetic valve, and described solenoid valve is controlled by described interlock contactor, can realize the interlock of described hydraulic drive mechanism and hydraulic actuator like this, and then the level of the electrohydraulic integration control of raising hydraulic system, not only make hydraulic system more convenient to operate, but also can satisfy the remotely-controlled requirement of hydraulic actuator.
In further technological scheme, inhale the element of draining the oil for inhaling the oil cylinder of draining the oil, this suction oil cylinder of draining the oil also has position transducer, and this position transducer can be drained the oil the piston motion of oil cylinder during to the precalculated position in suction, the generation prearranged signals; And then, utilize this technological scheme accurately to control to the drain the oil action of element of suction, to guarantee to inhale the oil cylinder oil suction in due course of draining the oil, replenish hydraulic oil to hyperbaric chamber in due course.
In further technological scheme, described position transducer links to each other with the interlock contactor, and described interlock contactor can produce the actions of the different control of signal hydraulic drive mechanism according to position transducer.This technological scheme can improve the automatic control performance of hydraulic system, guarantees the accurate reliability of control simultaneously.
In the operating method of hydraulic system provided by the invention, when described hydraulic actuator is carried out first predetermined action, by the sucking-off step, at least a portion hydraulic oil of the low-pressure cavity of the described hydraulic actuator of sucking-off.The operating method of this hydraulic system can produce the technique effect identical with above-mentioned hydraulic system.
In addition, in further technological scheme, described first predetermined action and sucking-off step are carried out simultaneously, can make first predetermined action in the overall process of carrying out, keep higher speed, and then guarantee the stability of first predetermined action.
The operating method of hydraulic system provided by the invention and hydraulic system is applicable to hydraulic pressure is carried out the higher hydraulic system of action request, carries out the accurate control of action to being specially adapted to the long hydraulic actuator of hydraulic circuit.
Embodiment
Describe the present invention below in conjunction with accompanying drawing, the description of this part only is exemplary and indicative, should any restriction not arranged to protection scope of the present invention.
Please refer to Fig. 1, this figure is the principle schematic of a kind of hydraulic system of providing of the embodiment of the invention one.The hydraulic system that embodiment one provides comprises main oil pipe road 100, auxiliary piping 200, solenoid directional control valve 1, operating cylinder 2, inhales drain the oil oil cylinder 4 and solenoid directional control valve 5.Solenoid directional control valve 1 is connected between main oil pipe road 100 and the operating cylinder 2, and with the action and the state of Control work oil cylinder 2, operating cylinder 2 can be carried out predetermined actions as the hydraulic actuator of hydraulic system.In this example, inhale the oil cylinder 4 of draining the oil as the suction element of draining the oil, driving oil cylinder 6 is inhaled oil cylinder 4 actions of draining the oil as drive mechanism, the drain the oil piston of oil cylinder 4 and the piston of driving oil cylinder 6 of suction is structure as a whole, like this, during the piston motion of driving oil cylinder 6, the piston of inhaling the oil cylinder 4 of draining the oil synchronously, motion simultaneously.The meaning of this structure is, can guarantee as driving mechanism action and the synchronism and the simultaneity of inhaling the element action of draining the oil.Solenoid directional control valve 5 is connected between main oil pipe road 100 and the driving oil cylinder 6, thereby can pass through the action and the state of solenoid directional control valve 5 controlling and driving oil cylinders 6, and then the action and the state of the oil cylinder 4 of draining the oil are inhaled in control.The drain the oil rodless cavity of oil cylinder 4 of described suction communicates by auxiliary piping 200 with the rodless cavity of operating cylinder 2, when changing with the rodless cavity volume at oil suction oil cylinder 4, enters an amount of hydraulic oil of hydraulic oil or sucking-off in the rodless cavity of operating cylinder 2.
Comprise oil feeding line 101 and oil return circuit 102 in the main oil pipe road 100, the P mouth of oil feeding line 101 (not shown) that links to each other with the oil supplying device of hydraulic system, the T mouth of oil return circuit 102 communicates with the hydraulic oil container (not shown) of hydraulic system.Oil feeding line 101 drives operating cylinder 2 and driving oil cylinder 6 and carries out suitable action for hydraulic system provides high pressure oil, and the low pressure oil of operating cylinder 2 and driving oil cylinder 6 is back in the fuel tank of hydraulic system by oil return circuit 102.For prevent when conversion action operating cylinder 2 out of control, guarantee to carry out the stability of action, between the oil feeding line 101 on main oil pipe road 100 and solenoid directional control valve 1, also be connected with sequence valve 11; The function of this sequence valve 11 is: when oil feeding line 101 pressure were lower than predetermined value, sequence valve 11 kept disconnecting, and the hydraulic oil in the operating cylinder 2 can not reflux by oil feeding line 101; During greater than predetermined value, sequence valve 11 remains closed at oil feeding line 101 pressure, and oil feeding line 101 can be supplied with high pressure oils to operating cylinder 2.
The hydraulic system that embodiment one provides comprises two kinds of working staties, and a kind of is that operating cylinder 2 is withdrawn under the hydraulic oil effect, and another kind is that operating cylinder 2 stretches out under the hydraulic oil effect; Under different working staties, inhale the oil cylinder 4 of draining the oil and carry out different actions.
When 2 withdrawals of needs operating cylinder, the Y1 in the solenoid directional control valve 1 gets electric, and the rod chamber of operating cylinder 2 is a hyperbaric chamber, communicates with oil feeding line 101 by sequence valve 11; Rodless cavity is a low-pressure cavity, communicates with oil return circuit 102; At this moment, because the piston-retraction of operating cylinder 2, the hydraulic oil of rodless cavity need pass through oil return circuit 102 drainings; But because there is return oil pressure in oil return circuit 102, the hydraulic oil in the rodless cavity is difficult to be back in the hydraulic oil container very soon.The Y1 of solenoid directional control valve 1 get electric in; Therefore, the Y4 of solenoid directional control valve 5 also electric, the rod chamber of driving oil cylinder 6 communicates with oil feeding line 101, rodless cavity communicates with oil return circuit 102, piston is moved to the left (be with Fig. 1 with reference to); And then make the piston of inhaling the oil cylinder 4 of draining the oil also to left movement, the drain the oil rodless cavity volume of oil cylinder 4 of suction increases sucking-off operating cylinder 2 rodless cavities, just the part hydraulic oil in the low-pressure cavity, return oil pressure in operating cylinder 2 rodless cavities is reduced, improve the retraction speed of operating cylinder 2.In order to guarantee the steady of whole operating cylinder 2 withdrawal actions, also on auxiliary piping 200, be connected with electromagnetic switch and adjust valve 3, this electromagnetic switch series flow control valve has two functions: the one, and when oil cylinder 4 actions were drained the oil in suction, electromagnetic switch series flow control valve Y5 got electric, and auxiliary piping 200 is communicated with; The 2nd,, adjust the size of the passage section of auxiliary piping, make and inhale the drain the oil piston of oil cylinder 4 and the piston synchronization motion of operating cylinder 2, and guarantee that the two has identical actuation time, make the oil-absorbing process of inhaling the oil cylinder 4 of draining the oil process, with the stationarity of the withdrawal action that guarantees operating cylinder 2 through the whole withdrawal action of operating cylinder 2.When preposition was arrived in the piston motion of operating cylinder 2, solenoid directional control valve 1 and solenoid directional control valve 5 cut off the power supply simultaneously, and operating cylinder 2 keeps lockup states; Driving oil cylinder 6 keeps static, and oil suction oil cylinder 4 stops oil suction.Electromagnetic switch series flow control valve 3 also can cut off the power supply simultaneously, and auxiliary piping 200 is disconnected; At this moment, the meaning that auxiliary piping 200 is disconnected is: the system pressure that can prevent hydraulic system is because the variation of load when suddenling change, and the hydraulic oil in the operating cylinder 2 flow into to be inhaled in the oil cylinder 4 of draining the oil, with the stability of assurance operating cylinder 2.
When needs operating cylinder 2 stretched out, the Y2 of solenoid directional control valve 1 got electric, and the rodless cavity and the rod chamber of operating cylinder 2 are all hyperbaric chamber, and communicated with oil feeding line 101 simultaneously; At this moment, because operating cylinder 2 rod chamber pressure are lower; When hydraulic system was given operating cylinder 2 fuel feeding, the P mouth pressure of oil feeding line 101 was lower, and sequence valve 11 is not opened.The Y2 of solenoid directional control valve 1 get electric in, the Y3 of the Y5 of electromagnetic switch series flow control valve 3 and solenoid directional control valve 5 gets, under the driving of driving oil cylinder 6, the drain the oil piston of oil cylinder 4 of suction moves right, the hydraulic oil of its suction is entered in the rodless cavity of operating cylinder 2, make operating cylinder 2 protruding under the differential pressure effect.When suction is drained the oil the piston of oil cylinder 4 when moving to the precalculated position, the pressure of the hydraulic oil in the oil feeding line 101 is raised to predetermined value, sequence valve 11 is opened, oil feeding line 101 passes through solenoid directional control valve 1 to operating cylinder 2 fuel feeding, it is protruding that operating cylinder 2 is continued under the effect of the hydraulic oil that oil feeding line 101 is supplied with, and carries out predetermined actions; Simultaneously, solenoid directional control valve 5 and 3 outages of electromagnetic switch series flow control valve are inhaled the oil cylinder 4 of draining the oil and are stopped oil extraction; Auxiliary piping 200 disconnects; The oil cylinder 4 original hydraulic oil that suck of so just suction being drained the oil have utilized.The meaning of this process is: not only can accelerate the motion speed of operating cylinder 2 pistons, can also save energy, improve the working efficiency of hydraulic system.It will be appreciated by those skilled in the art that, for when the P of oil feeding line 101 mouth pressure is low, driving oil cylinder 6 can drive inhales oil cylinder 4 actions of draining the oil, the oil cylinder sectional area of the sectional area of driving oil cylinder 6 and suction can being drained the oil is made as suitable dimensions, such as: what the cross section of driving oil cylinder 6 can be provided with is bigger, thereby at hydraulic fluid pressure hour, produces bigger active force, drive the suction motion that oil cylinder 4 is scheduled to of draining the oil.Auxiliary piping 200 disconnects the stability that can guarantee operating cylinder 2 equally.
In order to make the movement speed of inhaling oil cylinder 4 both directions of draining the oil consistent, and realize the smooth transition of action transfer process, can also on the oil circuit between solenoid directional control valve 5 and the driving oil cylinder 6, establish suitable throttle valve 7, with the passage section of adjustment oil circuit.
In order to make solenoid directional control valve 1, solenoid directional control valve 5 and electromagnetic switch series flow control valve 3 synchronization motions, the three is controlled by a through transport contactor, like this, when disconnection or closed interlock contactor, suitable control end is powered on simultaneously, carry out predetermined actions; Suitable relay can also be set, make above-mentioned each valve in a predetermined manner or sequence power-on.Be appreciated that in this example, stretch out, when inhaling hydraulic oil that the oil cylinder 4 of draining the oil sucks and all discharging, just need make driving oil cylinder 6 stop to move at operating cylinder 2; Therefore, as shown in Figure 1, can on oil cylinder 4 is drained the oil in suction, suitable position transducer 40 be set, this position transducer 40 can be when be drained the oil in oil cylinder 4 piston arrives precalculated positions in suction, produce prearranged signal, operator can make solenoid directional control valve 5 outage according to prearranged signals, make driving oil cylinder 6 stop action, and then make and inhale the oil cylinder 4 of draining the oil and keep static; When having the interlock contactor, position transducer 40 is linked to each other with the interlock contactor, and make of state and the action of interlock contactor according to the signal deciding solenoid directional control valve 5 or other the valve of position transducer 40; Certainly, when the interlock contactor makes solenoid directional control valve 5 outages, can make solenoid directional control valve 3 outages simultaneously, so that auxiliary piping 200 is cut off.Be appreciated that under specific circumstances, the control gear with respective processor can also be set,, satisfy actual demand with the action control that realizes that by electronic technology hydraulic system is more accurate, more complicated.
According to above description, as can be seen, the hydraulic system that embodiment one provides increases on the basis of existing hydraulic system inhales the element of draining the oil, state in realization on the basis of purpose, the stable and reliable operation advantage that can also keep hydraulic system can not cause adverse effect to the motion speed of hydraulic system; And, in practical operation, just can realize with less cost, can keep the good operating characteristics of hydraulic system simultaneously.
Among the embodiment one, solenoid directional control valve 1 is the 3-position-3-way valve, when the piston of operating cylinder 2 stretches out, rod chamber and rodless cavity are hyperbaric chamber, piston moves under the action of pressure of the hydraulic oil generation of rod chamber and rodless cavity, and at this moment, operating cylinder 2 is by the oil return circuit draining, therefore, there is not return oil pressure yet.Be appreciated that when operating cylinder 2 stretches out piston also can only stretch out under the pressure effect of rodless cavity hydraulic oil, in this case, the hydraulic oil of rod chamber need pass through the oil return circuit oil return, also can produce certain return oil pressure.
Please refer to Fig. 2, this figure is the principle schematic of the hydraulic system that provides of the embodiment of the invention two, this example is with embodiment one difference: change solenoid directional control valve 1 into three-position four-way valve, at operating cylinder 2 when stretching out, its rod chamber is a low-pressure cavity, by solenoid directional control valve 1 to oil return circuit 102 drainings; In order to reduce the return oil pressure of rod chamber, also be provided with electromagnetic switch series flow control valve 31, inhale drain the oil oil cylinder 41 and solenoid directional control valve 51, inhale the oil cylinder 41 of draining the oil and drive by a driving oil cylinder; Electromagnetic switch series flow control valve 31, inhale drain the oil oil cylinder 41 and solenoid directional control valve 51 function respectively electromagnetic switch series flow control valve 3, to inhale the oil cylinder 4 of draining the oil identical with solenoid directional control valve 5, when operating cylinder 2 stretches out, the suction rod chamber that oil cylinder 41 can sucking-off operating cylinder 2 of draining the oil, promptly the part hydraulic oil of Ci Shi low-pressure cavity reduces return oil pressure; When operating cylinder 2 withdrawals, inhale the rod chamber that the oil cylinder 41 of draining the oil can enter the hydraulic oil that sucks operating cylinder 2, promptly in Ci Shi the hyperbaric chamber, accelerate the retraction speed of operating cylinder 2; Its concrete working principle is identical with embodiment one, gives unnecessary details in this difference.The hydraulic system that this embodiment provides not only can be when operating cylinder be withdrawn, reduce the return oil pressure of low-pressure cavity, can also when operating cylinder stretches out, reduce the return oil pressure of low-pressure cavity, thereby can improve the speed of the execution action on operating cylinder 1 both direction.
Can accelerate the speed of the execution action on the both direction of operating cylinder 1 though be appreciated that hydraulic system that embodiment two provides, exist the hydraulic system parts many, baroque problem.For simplifying the structure of hydraulic system, the embodiment of the invention three provides the hydraulic system of another kind of structure.
Please refer to Fig. 3, the principle schematic of the hydraulic system that Fig. 3 provides for the embodiment of the invention three.Embodiment three improves to obtain on embodiment one basis; Equally, identical with embodiment two, change solenoid directional control valve 1 into three-position four-way valve, operating cylinder 2 is being stretched out, when its rod chamber is low-pressure cavity, by solenoid directional control valve 1 to oil return circuit 102 drainings; When operating cylinder 2 is stretched out, reduce the return oil pressure of rod chamber, the rod chamber of operating cylinder 2 is communicated with the rod chamber of inhaling the oil cylinder 4 of draining the oil,, also electromagnetic switch series flow control valve 3 is made as two-position four-way valve in order to control the connected relation of inhaling drain the oil oil cylinder 4 and operating cylinder 2.
The working principle of this hydraulic system is: when 2 withdrawals of needs operating cylinder, the Y1 in the solenoid directional control valve 1 gets electric, simultaneously, the Y4 of solenoid directional control valve 5 and the Y5 of electromagnetic switch series flow control valve 3 is got; The rod chamber of operating cylinder 2 is a hyperbaric chamber, communicates with oil feeding line 101; Rodless cavity is a low-pressure cavity, communicates with oil return circuit 102; At this moment, because the piston-retraction of operating cylinder 2, the hydraulic oil of rodless cavity need pass through the oil return circuit draining; Solenoid directional control valve 5 is moved to the left the piston of driving oil cylinder 6, and to left movement, the rodless cavity volume of inhaling the oil cylinder 4 of draining the oil increases the piston of inhaling the oil cylinder 4 of draining the oil under the driving of driving oil cylinder 6, and the rod chamber volume reduces; Electromagnetic switch series flow control valve 3 communicates rodless cavity and the rod chamber of inhaling the oil cylinder 4 of draining the oil respectively with the rodless cavity and the rod chamber of operating cylinder 2.Volume becomes drain the oil part hydraulic oil in the rodless cavity of rodless cavity sucking-off operating cylinder 2 of cylinder 4 of big suction, and simultaneously, the volume rod chamber of inhaling the cylinder 4 of draining the oil that diminishes enters an amount of hydraulic oil in the rod chamber of operating cylinder 2; At this moment, inhale the oil cylinder 4 of draining the oil and to reduce the return oil pressure of operating cylinder 2 rodless cavities by the part hydraulic oil of sucking-off low-pressure cavity on the one hand; On the other hand, when sucking the hydraulic oil of low-pressure cavity, a part of hydraulic oil is entered the rod chamber of operating cylinder 2, just in the hyperbaric chamber, can accelerate the retraction speed of operating cylinder 2, and then improve the working efficiency of hydraulic system hydraulic actuator.
When needs operating cylinder 2 stretched out, the Y2 in the solenoid directional control valve 1 got electric, simultaneously, the Y3 of solenoid directional control valve 5 and the Y5 of electromagnetic switch series flow control valve 3 was got; The rodless cavity of operating cylinder 2 is a hyperbaric chamber, communicates with oil feeding line 101; Rod chamber is a low-pressure cavity, communicates with oil return circuit 102; At this moment, because the piston-retraction of operating cylinder 2, the hydraulic oil of rodless cavity need pass through the oil return circuit draining; The drain the oil piston reverses direction of oil cylinder 4 of suction moves, and to left movement, the rod chamber volume of inhaling the oil cylinder 4 of draining the oil increases, and the rodless cavity volume reduces; Electromagnetic switch series flow control valve 3 communicates rodless cavity and the rod chamber of inhaling the oil cylinder 4 of draining the oil respectively with the rodless cavity and the rod chamber of operating cylinder 2.Volume becomes drain the oil part hydraulic oil in the rod chamber of rod chamber sucking-off operating cylinder 2 of cylinder 4 of big suction, and simultaneously, the volume rodless cavity of inhaling the cylinder 4 of draining the oil that diminishes enters an amount of hydraulic oil in the rodless cavity of operating cylinder 2; Can in the return oil pressure that reduces operating cylinder 2 rod chambers, further accelerate the speed of stretching out of operating cylinder 2 equally, and then improve the working efficiency of hydraulic system hydraulic actuator.
According to foregoing description, as can be seen, in the technological scheme that embodiment three provides, inhale the element of draining the oil and when hydraulic actuator carries out different actions, to bring into play identical effect; Can on two operative orientations of hydraulic actuator, improve the execution movement speed of hydraulic actuator on the one hand; On the other hand, because inhaling two hydraulic pressure cavity volumes of the element of draining the oil changes synchronously, and change in the opposite direction, therefore can be simultaneously at the part hydraulic oil of the low-pressure cavity of sucking-off hydraulic actuator, replenish suitable high pressure oil to the hyperbaric chamber of hydraulic actuator, the effect of two aspects can make the speed of action of hydraulic actuator faster.As can be seen, the rodless cavity of the oil cylinder of also suction can being drained the oil and rod chamber communicate with the rodless cavity of the rod chamber of operating cylinder respectively, can achieve the above object equally.
Being appreciated that hydraulic actuator is not limited to operating cylinder 2, can also be that oil hydraulic pump or oil hydraulic motor or other can be carried out the hydraulic element of predetermined action; The suction element of draining the oil also is not limited to inhale the oil cylinder of draining the oil, and can also be hydraulic element such as accumulator, oil scavenge pump; Drain the oil element during for other hydraulic element in hydraulic actuator and suction, first hydraulic pressure cavity of suitable hydraulic actuator and second hydraulic pressure cavity can be inhaled the chamber and second of draining the oil and inhaled the chamber of draining the oil and communicate with suction first of the element of draining the oil respectively, can reach above-mentioned effect equally.Certainly, driving the driving mechanism of inhaling the element of draining the oil can also have multiple choices, such as: with can in driving oil cylinder 6, establishing suitable spring, when its piston is moved right, drive, when its piston is moved to the left, rely on spring force to drive with hydraulic oil; Can use the motor driving oil scavenge pump, can also drive accumulator or the suction oil cylinder of draining the oil by suitable mechanical mechanism with motor, or the like.
In addition, be appreciated that among the embodiment three, also there is return oil pressure in the low-pressure cavity of driving oil cylinder 6, for the return oil pressure of the low-pressure cavity that reduces driving oil cylinder 6, can the auxiliary hydraulic pressure drive system be set for driving oil cylinder 6 and the suction oil cylinder 4 of draining the oil, and make the oil return circuit of driving oil cylinder 6 shorter; Under situation with auxiliary hydraulic pressure drive system, can also conveniently inhale the layout of drain the oil oil cylinder 4 and operating cylinder 2, make auxiliary piping 200 also keep shorter, to reduce the pressure loss of hydraulic system.
Providing on the basis of above-mentioned hydraulic system, a kind of operating method of hydraulic system also is provided, described hydraulic system comprises hydraulic actuator, to carry out predetermined actions; Described hydraulic actuator is being carried out first predetermined action, and when implementing corresponding operation, an one hydraulic pressure cavity links to each other with the hydraulic oil fuel tank by oil return circuit, is low-pressure cavity.When described hydraulic actuator is carried out first predetermined action, this method comprises the sucking-off step, with at least a portion hydraulic oil of the low-pressure cavity of the described hydraulic actuator of sucking-off, and then reduce the return oil pressure of hydraulic actuator low-pressure cavity, improve the speed of the execution action of hydraulic actuator.The hydraulic oil of low-pressure cavity that is appreciated that sucking-off is many more, and the return oil pressure of hydraulic actuator low-pressure cavity is more little, and the hydraulic oil of sucking-off appropriate amount can guarantee the stability and the reliability of the work of hydraulic actuator.In order to make hydraulic actuator keep higher execution speed in the overall process of carrying out first predetermined action, described first predetermined action and sucking-off step are carried out simultaneously, promptly begin action simultaneously, and make the sucking-off step all the time through first predetermined action; Like this, in the first predetermined action implementation, can make the hydraulic actuator low-pressure cavity keep less return oil pressure.
For the working efficiency that improves the hydraulic system hydraulic actuator is provided, can also be when described hydraulic actuator be carried out second predetermined action opposite with described first predetermined action, the hydraulic oil of sucking-off is entered in the hyperbaric chamber of hydraulic actuator.Its principle is described in hydraulic system, does not repeat them here.
Be appreciated that the operating method of implementing above-mentioned hydraulic system can realize by above-mentioned hydraulic system, also can utilize other modes to realize.
The above only is a preferred implementation of the present invention; should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the principle of the invention; can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.