CN210949339U - Landing leg automatic leveling hydraulic system - Google Patents
Landing leg automatic leveling hydraulic system Download PDFInfo
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- CN210949339U CN210949339U CN201921900026.6U CN201921900026U CN210949339U CN 210949339 U CN210949339 U CN 210949339U CN 201921900026 U CN201921900026 U CN 201921900026U CN 210949339 U CN210949339 U CN 210949339U
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Abstract
The utility model provides a hydraulic system for automatically leveling supporting legs, which comprises an oil pump and a plurality of supporting leg oil cylinders connected in parallel at the oil outlet of the oil pump; an oil inlet of each support oil cylinder is provided with a three-position four-way electromagnetic directional valve; the two-position two-normally-off electromagnetic proportional valve and the three-way pressure compensator are also included; the two-position two-normally-off electromagnetic proportional valve is positioned between the oil outlet of the oil pump and the three-position four-way electromagnetic reversing valve. The three-way pressure compensator keeps the pressure difference of the oil inlet and the oil outlet of the two-position two-normally-off electromagnetic proportional valve constant, so that the flow of the two-position two-normally-off electromagnetic proportional valve is only related to the current of the valve head coil; by controlling the current of the valve head coil of the two-position two-normally-off electromagnetic proportional valve, the smooth and stable action of the support leg oil cylinder is ensured, namely, the automatic leveling function of the support leg is safe and reliable; the system pressure impact generated when the three-position four-way electromagnetic reversing valve alternately acts is buffered, namely the pressure impact is small in the automatic leveling process of the supporting leg.
Description
Technical Field
The utility model relates to an engineering machine tool hydraulic control equipment field especially relates to a landing leg automatic leveling hydraulic system.
Background
When equipment such as an aerial work vehicle, a crane vehicle and the like is used for aerial work, the vehicle body needs to be supported and leveled through the hydraulic support legs. In the supporting leg leveling process, when the inclination angle of the frame exceeds the allowed angle, the inclination angle sensor can detect the specific inclined position of the frame, and the controller gives corresponding instructions to the corresponding supporting leg oil cylinder to correspondingly extend or retract the supporting leg oil cylinder so as to keep the frame in the allowed inclination angle range.
The hydraulic oil pump in the supporting leg automatic leveling system is usually a fixed displacement pump, and when the rotating speed of the oil pump is fixed, the output flow of the oil pump is a fixed value.
The landing leg leveling valve in the existing landing leg automatic leveling system only comprises four three-position four-way electromagnetic directional valves and one overflow valve, and has the following defects:
a. and the automatic leveling reliability is low.
In the automatic leveling process of the supporting legs, in order to ensure the rapidity of leveling, the four three-position four-way electromagnetic directional valves are all opened before the four supporting legs are grounded, and the required output flow of an oil pump is large; when the four support legs are grounded, the four three-position four-way electromagnetic directional valves are correspondingly opened as required, and the output flow of the required oil pump is small; in the automatic leveling process after the four support legs touch the ground, the oil cylinders of the corresponding support legs act too fast due to large actual output flow of the oil pumps, the system does not respond in time, and the automatic leveling function of the support legs is often failed.
The problem can be solved by reducing the rotating speed of the oil pump, namely, before the four support legs touch the ground, the oil pump is at a high rotating speed, and the output flow of the oil pump is large; after the four support legs are grounded, the oil pump is at a low rotating speed, and the output flow of the oil pump is small. However, in some cases, the oil pump rotational speed is not adjustable; or even if the rotation speed is adjustable, problems such as insufficient engine power and flameout may occur.
b. The automatic leveling impact is large.
After the four support legs are grounded, the four three-position four-way electromagnetic reversing valves correspondingly and alternately act according to needs, and the system pressure is alternately high-pressure (overflow pressure of an overflow valve) and low-pressure (load pressure) in the alternate action process of the reversing valves, so that the impact of an oil pressure system can be caused.
SUMMERY OF THE UTILITY MODEL
In order to solve the problems, the utility model provides a hydraulic system for automatically leveling a supporting leg, which ensures that the action of a supporting leg oil cylinder is smooth and stable, namely the automatic leveling function of the supporting leg is safe and reliable; the system pressure impact generated when the three-position four-way electromagnetic reversing valve alternately acts is buffered, namely the pressure impact is small in the automatic leveling process of the supporting leg.
The technical scheme is as follows: the utility model provides a hydraulic system for automatically leveling supporting legs, which comprises an oil pump and a plurality of supporting leg oil cylinders connected in parallel at the oil outlet of the oil pump; an oil inlet of each support oil cylinder is provided with a three-position four-way electromagnetic directional valve; the two-position two-normally-off electromagnetic proportional valve and the three-way pressure compensator are also included; the two-position two-normally-off electromagnetic proportional valve is positioned between the oil outlet of the oil pump and the three-position four-way electromagnetic reversing valve; the three-way pressure compensator is used for keeping the pressure difference of the oil inlet and the oil outlet of the two-position two-normally-off electromagnetic proportional valve constant.
Further, an oil inlet of the three-way pressure compensator is connected with oil inlets of two-position two normally-off electromagnetic proportional valves; an oil outlet of the three-way pressure compensator is connected with an oil return pipeline; and a pressure guide oil port of the three-way pressure compensator is connected with oil outlets of the two-position normally-off electromagnetic proportional valves.
Further, the device also comprises a two-way flow valve; the oil inlet of the two-way flow valve is connected with the oil outlet of the two-position two-normally-off electromagnetic proportional valve, and the oil outlet of the two-way flow valve is connected with the oil return pipeline.
Further, the device also comprises an overflow valve; the oil inlet of the overflow valve is connected with the oil outlet of the oil pump, and the oil outlet of the overflow valve is connected with the oil return pipeline.
Further, an oil inlet of the three-position four-way electromagnetic directional valve is connected with an oil outlet of the two-position two-normally-off electromagnetic proportional valve; and an oil return port of the three-position four-way electromagnetic reversing valve is connected with an oil return pipeline.
Further, the device also comprises an oil tank; the oil suction port of the oil pump is connected with the oil tank; the oil return pipeline is connected with an oil tank.
Has the advantages that: the utility model keeps the pressure difference of the oil inlet and the oil outlet of the two-position two-normally-off electromagnetic proportional valve constant through the three-way pressure compensator, so that the flow passing through the two-position two-normally-off electromagnetic proportional valve is only related to the valve head coil current of the two-position two-normally-off electromagnetic proportional valve; before the four support legs are grounded, the three-position four-way electromagnetic directional valve is completely opened, a valve head coil of the two-position two-way normally-off electromagnetic proportional valve is high in current, and the leveling rapidity is guaranteed due to the fact that the flow rate of the two-position two-way normally-off electromagnetic proportional valve is high; the large current of the valve head coil of the two-position normally-off electromagnetic proportional valve is kept unchanged, and the large current flowing to the four supporting leg oil cylinders is kept unchanged.
After the four supporting legs are grounded, part of the three-position four-way electromagnetic directional valve is closed, the valve head coil of the two-position two-way normally-off electromagnetic proportional valve is low in current, the flow through the two-position two-way normally-off electromagnetic proportional valve is small, the oil quantity flowing to the four supporting leg oil cylinders is reduced, and the supporting leg oil cylinders are guaranteed to act smoothly and stably. And keeping the small current of the valve head coil of the two-position normally-off electromagnetic proportional valve unchanged, and keeping the small flow flowing to the four supporting leg oil cylinders unchanged. The three-way pressure compensator ensures that the pressure difference of the oil inlet and the oil outlet of the two-position two-normally-off electromagnetic proportional valve is constant, and simultaneously, the redundant flow flows back to the oil tank.
In the leveling process after the four support legs are grounded, the four three-position four-way electromagnetic directional valves alternately act, and the three-way pressure compensator delays the switching time of the load pressure and the system overflow pressure and buffers the system pressure impact.
In conclusion, the utility model ensures the smooth and stable action of the supporting leg oil cylinder, namely the automatic leveling function of the supporting leg is safe and reliable; the system pressure impact generated when the three-position four-way electromagnetic reversing valve alternately acts is buffered, namely the pressure impact is small in the automatic leveling process of the supporting leg.
Drawings
FIG. 1 is a flow chart of the present invention;
fig. 2 is a schematic diagram of the use of the present invention to level the legs.
Detailed Description
As shown in fig. 1 and 2, a hydraulic system for automatically leveling a support leg comprises an oil pump 1 and four support leg oil cylinders 2 connected in parallel at an oil outlet of the oil pump 1; and an oil inlet of each support oil cylinder 2 is provided with a three-position four-way electromagnetic directional valve 3. An oil inlet of the three-position four-way electromagnetic directional valve 3 is connected with oil outlets of the two-position two-normally-off electromagnetic proportional valve 4; and an oil return port of the three-position four-way electromagnetic reversing valve 3 is connected with an oil return pipeline. The supporting leg oil cylinder comprises a large cavity and a small cavity, wherein the large cavity is communicated with a working oil port A of the three-position four-way electromagnetic reversing valve 3, and the small cavity is communicated with a working oil port B of the three-position four-way electromagnetic reversing valve 3.
The oil return pipeline is communicated to the oil tank 8; the oil suction port of the oil pump 1 is connected with an oil tank 8.
The utility model also comprises a two-position two-way normally-off electromagnetic proportional valve 4 and a three-way pressure compensator 5; the two-position two-normally-off electromagnetic proportional valve 4 is positioned between an oil outlet of the oil pump 1 and the three-position four-way electromagnetic directional valve 3. The valve port opening degree of the two-position two-normally-off electromagnetic proportional valve 4 is only related to the valve head coil current, and the flow of the two-position two-normally-off electromagnetic proportional valve 4 can be controlled by adjusting the valve head coil current of the two-position two-normally-off electromagnetic proportional valve 4.
An oil inlet of the three-way pressure compensator 5 is connected with oil inlets of the two-position two normally-off electromagnetic proportional valves 4; an oil outlet of the three-way pressure compensator 5 is connected with an oil return pipeline; and a pressure guide oil port of the three-way pressure compensator 5 is connected with oil outlets of the two-position normally-off electromagnetic proportional valves 4. The three-way pressure compensator 5 is used for keeping the pressure difference of the oil inlet and the oil outlet of the two-position two-normally-off electromagnetic proportional valve 4 constant, so that the flow passing through the two-position two-normally-off electromagnetic proportional valve 4 is only related to the valve head coil current of the two-position two-normally-off electromagnetic proportional valve 4.
In this embodiment, the input current of the valve head coil of the two-position two-normally-off electromagnetic proportional valve 4 is controlled in two stages, namely, high current and low current. When the leveling is automatically carried out, before the four support legs are grounded, the three-position four-way electromagnetic directional valve 3 is completely opened, the valve head coil input current of the two-position two-normally-off electromagnetic proportional valve 4 is large, the flow rate flowing to the four support leg oil cylinders 2 through the two-position two-normally-off electromagnetic proportional valve 4 is large, and the leveling rapidity is ensured; the large current of the valve head coil of the two-position normally-off electromagnetic proportional valve is kept unchanged, and the large current flowing to the four supporting leg oil cylinders 2 is kept unchanged.
After the four supporting legs are grounded, part of the three-position four-way electromagnetic directional valve 3 is closed, the valve head coil of the two-position two-open normally-closed electromagnetic proportional valve 4 is low in current, the flow through the two-position two-open normally-closed electromagnetic proportional valve 4 is small, the oil amount flowing to the four supporting leg oil cylinders 2 is reduced, and the supporting leg oil cylinders 2 are guaranteed to act smoothly and stably. And keeping the small current of the valve head coil of the two-position two-normally-off electromagnetic proportional valve 4 unchanged, and keeping the small flow flowing to the four supporting leg oil cylinders 2 unchanged. The three-way pressure compensator 5 ensures that the pressure difference of the oil inlet and the oil outlet of the two-position two-normally-off electromagnetic proportional valve 4 is constant, and simultaneously, the redundant flow flows back to the oil tank 8.
In the leveling process after the four support legs are grounded, the four three-position four-way electromagnetic directional valves 3 alternately act, the three-way pressure compensator 5 delays the switching time of the load pressure and the system overflow pressure, and the system pressure impact is buffered.
In conclusion, the utility model ensures the smooth and stable action of the supporting leg oil cylinder 2, namely the automatic leveling function of the supporting leg is safe and reliable; the system pressure impact generated when the three-position four-way electromagnetic reversing valve 3 alternately acts is buffered, namely the pressure impact is small in the automatic leveling process of the supporting leg.
The utility model also comprises a two-way flow valve 6; the oil inlet of the two-way flow valve 6 is connected with the oil outlet of the two-position two-normally-off electromagnetic proportional valve 4, and the oil outlet of the two-way flow valve 6 is connected with the oil return pipeline. When the hydraulic system is not working, the two-way flow valve 6 is used for discharging the system pressure.
The utility model also comprises an overflow valve 7; an oil inlet of the overflow valve 7 is connected with an oil outlet of the oil pump 1, and an oil outlet of the overflow valve 7 is connected with the oil return pipeline. When the system pressure exceeds the overflow pressure of the overflow valve in an abnormal condition, the overflow valve overflows and unloads to protect the safety of each device.
Claims (6)
1. A hydraulic system for automatically leveling supporting legs comprises an oil pump (1) and a plurality of supporting leg oil cylinders (2) which are connected in parallel at an oil outlet of the oil pump (1); an oil inlet of each support oil cylinder (2) is provided with a three-position four-way electromagnetic directional valve (3); the method is characterized in that: the two-position two-normally-off electromagnetic proportional valve also comprises a two-position two-normally-off electromagnetic proportional valve (4) and a three-way pressure compensator (5); the two-position two-normally-off electromagnetic proportional valve (4) is positioned between the oil outlet of the oil pump (1) and the three-position four-way electromagnetic directional valve (3); the three-way pressure compensator (5) is used for keeping the pressure difference of the oil inlet and the oil outlet of the two-position normally-off electromagnetic proportional valve (4) constant.
2. The leg self-leveling hydraulic system as claimed in claim 1, wherein: an oil inlet of the three-way pressure compensator (5) is connected with oil inlets of two normally-off electromagnetic proportional valves (4); an oil outlet of the three-way pressure compensator (5) is connected with an oil return pipeline; and a pressure guide oil port of the three-way pressure compensator (5) is connected with an oil outlet of the two-position normally-off electromagnetic proportional valve (4).
3. The leg self-leveling hydraulic system as claimed in claim 2, wherein: the device also comprises a two-way flow valve (6); the oil inlet of the two-way flow valve (6) is connected with the oil outlet of the two-position normally-off electromagnetic proportional valve (4), and the oil outlet of the two-way flow valve (6) is connected with the oil return pipeline.
4. The leg self-leveling hydraulic system as claimed in claim 3, wherein: the device also comprises an overflow valve (7); an oil inlet of the overflow valve (7) is connected with an oil outlet of the oil pump (1), and an oil outlet of the overflow valve (7) is connected with the oil return pipeline.
5. The leg self-leveling hydraulic system as claimed in claim 4, wherein: an oil inlet of the three-position four-way electromagnetic directional valve (3) is connected with an oil outlet of the two-position two-normally-off electromagnetic proportional valve (4); and an oil return port of the three-position four-way electromagnetic reversing valve (3) is connected with an oil return pipeline.
6. The leg self-leveling hydraulic system as claimed in claim 5, wherein: the device also comprises an oil tank (8); an oil suction port of the oil pump (1) is connected with an oil tank (8); the oil return pipeline is connected with an oil tank (8).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921900026.6U CN210949339U (en) | 2019-11-06 | 2019-11-06 | Landing leg automatic leveling hydraulic system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921900026.6U CN210949339U (en) | 2019-11-06 | 2019-11-06 | Landing leg automatic leveling hydraulic system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN210949339U true CN210949339U (en) | 2020-07-07 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201921900026.6U Active CN210949339U (en) | 2019-11-06 | 2019-11-06 | Landing leg automatic leveling hydraulic system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN210949339U (en) |
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2019
- 2019-11-06 CN CN201921900026.6U patent/CN210949339U/en active Active
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