Model utility content
In view of this, the utility model proposes a kind of potential energy recovering hydraulic system and engineering machinery, with solve circularly enhancing identical load time, accumulator also can provide pressure oil problem.
On the one hand, the utility model provides a kind of potential energy recovering hydraulic system, comprise oil pump, oil cylinder, accumulator, the first control valve, the second control valve, fuel tank, the first control valve is connected in the oil circuit between oil cylinder rodless cavity and oil pump delivery outlet, also comprise the 3rd control valve and the 4th control valve, the 3rd control valve is connected to oil cylinder rodless cavity and is connected in oil circuit with cylinder rod chamber, the second control valve is connected between accumulator and oil cylinder rodless cavity in oil circuit, and the 4th control valve is connected to cylinder rod chamber and is connected in oil circuit with fuel tank.
Further, also comprise relief valve, the inlet opening of relief valve is connected with accumulator, and the delivery outlet of relief valve is connected with fuel tank.
Further, also comprise equilibrium valve, equilibrium valve is connected to oil cylinder rodless cavity and is connected in oil circuit with the first control valve.
Further, the first control valve, the second control valve, the 3rd control valve, the 4th control valve are solenoid directional control valve or hydraulic changeover valve or hand-operated direction valve.
Further, the second control valve, the 3rd control valve, the 4th control valve are cartridge valve or Pilot operated check valve.
Further, also comprise control system, the first control valve, the second control valve, the 3rd control valve, the 4th control valve are solenoid directional control valve, and described control system is electrically connected with the control end of the first control valve, the second control valve, the 3rd control valve, the 4th control valve.
Further, also comprise safety valve, in the oil circuit of safety valve between oil pump delivery outlet and fuel tank.
Further, also comprise the pressure detecting element being connected with control system, pressure detecting element is for detection of the rodless cavity of oil cylinder and the pressure of accumulator outlet.
A kind of engineering machinery is also provided in addition, has comprised above-mentioned potential energy recovering hydraulic system.
A kind of potential energy recovering hydraulic system that the utility model provides, in load potential energy callback course, oil cylinder rodless cavity and cylinder rod chamber are connected, the pressure that making to promote load needs is less than the pressure that load decline produces, because in potential energy callback course, oil cylinder rodless cavity and cylinder rod chamber are connected, load active area is the difference in areas between oil cylinder rodless cavity and cylinder rod chamber, and in lifting loading process, load active area is oil cylinder rodless cavity area, therefore the pressure that both will inevitably make lifting heavy need is less than the pressure that weight decline produces.So decline and promote in the operating mode of identical weight load in load, accumulator also can directly do work to oil cylinder, has increased the scope of the applying working condition of system.The engineering machinery of what the utility model provided have this potential energy recovering hydraulic system, has above-mentioned beneficial effect equally.
Embodiment
It should be noted that, in the situation that not conflicting, the feature in embodiment and embodiment in the utility model can combine mutually.Describe below with reference to the accompanying drawings and in conjunction with the embodiments the utility model in detail.
As shown in Figure 1, the preferred potential energy recovering hydraulic system of the utility model comprises oil pump 1, oil cylinder 6, accumulator 9, the first control valve 3, the second control valve 10, relief valve 11, fuel tank 12, the first control valve 3 is connected in the oil circuit between oil cylinder 6 rodless cavities and oil pump 1 delivery outlet, the second control valve 10 is connected between accumulator 9 and oil cylinder 6 rodless cavities in oil circuit, the inlet opening of relief valve 11 is connected with accumulator 9, and the delivery outlet of relief valve 11 is connected with fuel tank 12.
The first control valve 3 is solenoid directional control valve, is controlled by control system 4.Also can adopt pilot operated directional control valve or hand-operated direction valve.For the break-make of oil circuit between control oil pump 1 and oil cylinder 6 rodless cavities.The second control valve 10 is solenoid directional control valve, also can adopt pilot operated directional control valve or hand-operated direction valve or Pilot operated check valve or cartridge valve etc., for controlling the break-make of oil circuit between accumulator 9 and oil cylinder 6 rodless cavities.
In addition, also comprise that the 3rd control valve 8, the three control valves 8 are connected to oil cylinder 6 rodless cavities and are connected in oil circuit with oil cylinder 6 rod chambers, for controlling oil circuit break-make between oil cylinder 6 rodless cavities and oil cylinder 6 rod chambers.The 3rd control valve 8 is solenoid directional control valve, also can adopt pilot operated directional control valve or hand-operated direction valve or Pilot operated check valve or cartridge valve etc.
In addition, also comprise that the 4th control valve 7, the four control valves 7 are connected to oil cylinder 6 rod chambers and are connected in oil circuit with fuel tank 12.The 4th control valve 7 is solenoid directional control valve, also can adopt pilot operated directional control valve or hand-operated direction valve or Pilot operated check valve or cartridge valve etc., for controlling the break-make of oil circuit between fuel tank 12 and oil cylinder 6 rod chambers.
In addition, can also comprise equilibrium valve, equilibrium valve is connected to oil cylinder 6 rodless cavities and is connected in oil circuit with the first control valve 3.Be used for preventing that load downloading process from security incident occurring.Control by control system 4.
In addition, in oil pump 1 output circuit, be also provided with safety valve 2, in the time that oil pump 1 pressure reaches safety valve 2 set pressure, safety valve 2 is opened step-down.
In such scheme, the first control valve 3, the second control valve 10, the 3rd control valve 8, the 4th control valve 7 can be solenoid directional control valve, and control system 4 is electrically connected with the control end of the first control valve 3, the second control valve 10, the 3rd control valve 8, the 4th control valve 7.
In such scheme, the pressure detecting element being connected with control system 4 can be set, the pressure exporting for detection of rodless cavity and the accumulator 9 of oil cylinder 6, like this, pressure control the first control valve 3, the second control valve 10, the 3rd control valve 8, the 4th control valve 7 that can export according to the rodless cavity of oil cylinder 6 and accumulator 9, realize automation control.
Specific implementation process is as follows:
1) oil cylinder 6 promotes loading process:
If accumulator 9 internal pressures are less than or equal to oil pump 1 outlet pressure, the 4th control valve 7 must not electricity, the 3rd control valve 8 electric, the second control valve 10 all must not be electric, the first control valve 3 is in left position, the pressure oil that now oil pump 1 exports enters the rodless cavity of oil cylinder 6 through the left position of the first control valve 3, equilibrium valve 5, the rod chamber hydraulic oil of oil cylinder 6 flows back to fuel tank 12 through the 4th control valve 7, and accumulator 9 is in closed state, and oil cylinder 6 promotes load institute energy requirement and comes from oil pump 1 completely.
If accumulator 9 internal pressures are greater than oil pump 1 outlet pressure, the second control valve 10 obtains electric, the flow that simultaneously can control the pressure oil that accumulator 9 discharges mates oil pump 1 flow, the speed that makes oil cylinder 6 promote load meets the requirements, the 4th control valve 7 must not be electric simultaneously, the 3rd control valve 8 obtains electric, now there are two strands of hydraulic oil to flow into the rodless cavity of oil cylinder 6, one is the pressure oil that oil pump 1 is exported, another strand is the pressure oil of accumulator 9 interior storages flows into oil cylinder 6 together with converging with working connection rodless cavity through the second control valve 10, the rod chamber hydraulic oil of oil cylinder 6 flows back to fuel tank 12 through the 4th control valve 7.
2) load decline process:
The second control valve 10 must not be electric, and the 4th control valve 7 obtains electric, and the 3rd control valve 8 must not be electric, and the first control valve 3 is in meta, and equilibrium valve 5 is opened simultaneously, and now oil cylinder 6 is retracted under the effect of load deadweight.Now the rodless cavity of the rod chamber of oil cylinder 6 and oil cylinder 6 is communicated with, but disconnects with accumulator 9.
Contrast pressure and accumulator 9 internal pressures of oil cylinder 6 rodless cavities by detection.If the rodless cavity internal pressure of accumulator 9 internal pressures >=oil cylinder 6, can control the first control valve 3 by control system 4 and make it in right position, make the rodless cavity hydraulic oil oil sump tank of oil cylinder 6.
If the rodless cavity internal pressure of accumulator 9 internal pressure < oil cylinders 6 makes the second control valve 10 obtain electric, the 4th control valve 7 obtains electric, the 3rd control valve 8 must not be electric, equilibrium valve 5 is opened simultaneously, and the first control valve 3 is in meta, and now oil cylinder 6 is retracted under the effect of load deadweight.Now, because the 3rd control valve 8 must not be electric, the second control valve 10 obtains electric, so the rodless cavity of oil cylinder 6 is communicated with rod chamber, while and accumulator 9 are communicated with.In oil cylinder 6 retraction processes, oil cylinder 6 rodless cavity part pressure oils enter rod chamber, and another part pressure oil enters accumulator 9 and stores, and in the time that the pressure in accumulator 9 exceedes relief valve 11 pressure, relief valve 11 is opened release.
This kind of situation can make the pressure of the hydraulic oil of accumulator 9 interior storages will be when promoting identical load the required force value of rodless cavity.Computational process is as follows
Decline pressure process is calculated as follows:
P
1·A
1=F
S+P
2·A
2 (1)
P
1for rodless cavity pressure, P
2for rod chamber pressure, A
1for rodless cavity area, A
2for rod chamber area, F
sfor load gravity, because oil cylinder 6 rodless cavities are communicated with rod chamber, therefore, P
1=P
2, be also accumulator 9 pressure reservoir pressure P' simultaneously, can obtain according to above formula (1):
Lifting process calculation of pressure is as follows:
While promoting identical load, the required pressure of rodless cavity is:
Can be obtained by upper two formulas (2) (3), for self system, while promoting identical load, accumulator 9 also can provide pressure oil as auxiliary oil sources.
Therefore decline and promote under the operating mode of identical weight load, the pressure oil that accumulator 9 is collected in decline process also can have portion of energy utilized in lifting process, and this depends on the Area Ratio of rod chamber and rodless cavity.
The engineering machinery that the utility model provides, comprises above-mentioned potential energy recovering hydraulic system, can decline and promote in the operating mode of identical weight load in load, and accumulator 9 also can directly do work to oil cylinder 6, has increased the scope of the applying working condition of system.Can reduce Construction Machinery Energy Saving reduction of discharging and the preparation of engineering machinery power, reduce manufacture cost simultaneously.
The foregoing is only preferred embodiment of the present utility model; not in order to limit the utility model; all within spirit of the present utility model and principle, any modification of doing, be equal to replacement, improvement etc., within all should being included in protection domain of the present utility model.