阅读说明：本技术 用于油缸控制的液压系统 (Hydraulic system for controlling oil cylinder ) 是由 张三喜 于 2020-04-30 设计创作，主要内容包括：本公开提供了一种用于油缸控制的液压系统,属于油缸技术领域。所述液压系统包括油箱、液压泵、油缸组件和控制组件,油缸组件包括第一三位四通换向阀、第一液控单向阀、第二液控单向阀和油缸,控制组件包括第一换向阀、第二换向阀、蓄能器和溢流阀,第一换向阀的第一油口与液压泵的出油口连通,第一换向阀的第二油口与蓄能器连通,溢流阀的进油口分别与液压泵的出油口、溢流阀的第一控制油口连通,溢流阀的出油口与油箱的回油口连通,溢流阀的第二控制油口与第二换向阀的第一油口连通,第二换向阀的第二油口与蓄能器连通。本公开提供的液压系统可以在应急情况下仍能保持油缸正常工作。(The utility model provides a hydraulic system for hydro-cylinder control belongs to hydro-cylinder technical field. The hydraulic system comprises an oil tank, a hydraulic pump, an oil cylinder assembly and a control assembly, wherein the oil cylinder assembly comprises a first three-position four-way reversing valve, a first hydraulic control one-way valve, a second hydraulic control one-way valve and an oil cylinder, the control assembly comprises a first reversing valve, a second reversing valve, an energy accumulator and an overflow valve, a first oil port of the first reversing valve is communicated with an oil outlet of the hydraulic pump, a second oil port of the first reversing valve is communicated with the energy accumulator, an oil inlet of the overflow valve is communicated with an oil outlet of the hydraulic pump and a first control oil port of the overflow valve respectively, an oil outlet of the overflow valve is communicated with an oil return port of the oil tank, a second control oil port of the overflow valve is communicated with a first oil port of the second reversing valve, and a second oil port. The hydraulic system provided by the disclosure can still keep the oil cylinder to normally work under the emergency condition.)

1. A hydraulic system for cylinder control, characterized in that the hydraulic system comprises an oil tank (1), a hydraulic pump (2), a cylinder assembly (3) and a control assembly (4);

an oil outlet of the oil tank (1) is communicated with an oil inlet of the hydraulic pump (2);

the oil cylinder assembly (3) comprises a first three-position four-way reversing valve (31), a first hydraulic control one-way valve (32), a second hydraulic control one-way valve (33) and an oil cylinder (34), an oil inlet of the first three-position four-way reversing valve (31) is communicated with an oil outlet of the hydraulic pump (2), an oil return port of the first three-position four-way reversing valve (31) is communicated with an oil return port of the oil tank (1), a first working oil port of the first three-position four-way reversing valve (31) is respectively communicated with an oil inlet of the first hydraulic control one-way valve (32) and a control oil port of the second hydraulic control one-way valve (33), a second working oil port of the first three-position four-way reversing valve (31) is respectively communicated with a control oil port of the first hydraulic control one-way valve (32) and an oil inlet of the second hydraulic control one-way valve (33), an oil outlet of the first hydraulic control one-way valve (32) is communicated with a rod cavity of, an oil outlet of the second hydraulic control one-way valve (33) is communicated with a rodless cavity of the oil cylinder (34);

the control assembly (4) comprises a first reversing valve (41), a second reversing valve (42), an energy accumulator (43) and an overflow valve (44), a first oil port of the first reversing valve (41) is communicated with an oil outlet of the hydraulic pump (2), a second oil port of the first reversing valve (41) is communicated with the energy accumulator (43), an oil inlet of the overflow valve (44) is communicated with an oil outlet of the hydraulic pump (2) and a first control oil port of the overflow valve (44), an oil outlet of the overflow valve (44) is communicated with an oil return port of the oil tank (1), a second control oil port of the overflow valve (44) is communicated with a first oil port of the second reversing valve (42), and a second oil port of the second reversing valve (42) is communicated with the energy accumulator (43).

2. The hydraulic system according to claim 1, characterized in that the hydraulic system further comprises a cylinder control assembly (5), the cylinder control assembly (5) comprises an electromagnetic directional valve (51), a third hydraulic control one-way valve (52) and a fourth hydraulic control one-way valve (53), a first oil port of the electromagnetic directional valve (51) is communicated with the energy accumulator (43), a second oil port of the electromagnetic directional valve (51) is communicated with a control oil port of the third hydraulic control one-way valve (52), an oil return port of the electromagnetic directional valve (51) is communicated with an oil return port of the oil tank (1), an oil outlet of the third hydraulic control one-way valve (52) is communicated with the energy accumulator (43), an oil inlet of the third hydraulic control one-way valve (52) is communicated with a rod cavity of the cylinder (34), an oil outlet of the fourth hydraulic control one-way valve (53) is communicated with a rodless cavity of the cylinder (34), an oil inlet of the fourth hydraulic control one-way valve (53) is communicated with an oil return port of the oil tank (1), and a control oil port of the fourth hydraulic control one-way valve (53) is communicated with an oil inlet of the third hydraulic control one-way valve (52).

3. Hydraulic system according to claim 2, characterized in that the hydraulic system further comprises a drain assembly (6), the oil drainage component (6) comprises a fifth hydraulic control one-way valve (61) and a second three-position four-way reversing valve (62), an oil outlet of the fifth hydraulic control one-way valve (61) is communicated with an oil inlet of the third hydraulic control one-way valve (52), an oil inlet of the fifth hydraulic control one-way valve (61) is communicated with a second working oil port of the second three-position four-way reversing valve (62), a control oil port of the fifth hydraulic control one-way valve (61) is communicated with a first working oil port of the second three-position four-way reversing valve (62), an oil inlet of the second three-position four-way reversing valve (62) is communicated with a first oil port of the first reversing valve (41), and an oil return port of the second three-position four-way reversing valve (62) is communicated with an oil return port of the oil tank (1).

4. The hydraulic system as claimed in claim 3, wherein the oil drainage assembly (6) further comprises a first check valve (7), an oil inlet of the first check valve (7) is communicated with an oil inlet of the third hydraulic control check valve (52), and an oil outlet of the first check valve (7) is communicated with a rod cavity of the oil cylinder (34).

5. The hydraulic system according to any one of claims 1 to 4, characterized in that it comprises a second one-way valve (8), the oil inlet of said second one-way valve (8) being in communication with the oil outlet of said hydraulic pump (2), the oil outlet of said second one-way valve (8) being in communication with the oil inlet of said first three-position, four-way reversing valve (31).

6. The hydraulic system according to any one of claims 1-4, characterized in that the hydraulic system comprises a third check valve (9), an oil inlet of the third check valve (9) is communicated with an oil outlet of the hydraulic pump (2), and an oil outlet of the third check valve (9) is communicated with a first oil port of the first directional control valve (41).

7. The hydraulic system according to any one of claims 1 to 4, characterized in that it further comprises a filter (10), the oil inlet of said filter (10) being in communication with the oil outlet of said hydraulic pump (2), the oil outlet of said filter (10) being in communication with the oil inlet of said first three-position four-way reversing valve (31).

8. The hydraulic system according to any one of claims 1 to 4, characterized in that the hydraulic system further comprises a safety valve (11), an oil inlet of the safety valve (11) is communicated with an oil outlet of the hydraulic pump (2), an oil outlet of the safety valve (11) is communicated with an oil return port of the oil tank (1), and a control oil port of the safety valve (11) is communicated with an oil inlet of the safety valve (11).

9. The hydraulic system according to any one of claims 1 to 4, further comprising an exhaust valve (12), the exhaust valve (12) communicating between a return of the first three-position, four-way reversing valve (31) and a return of the tank (1).

10. The hydraulic system according to any one of claims 1 to 4, further comprising a pressure gauge (13), wherein the pressure gauge (13) is interposed between an oil outlet of the hydraulic pump (2) and an oil inlet of the first three-position four-way reversing valve (31).

Technical Field

The disclosure belongs to the technical field of oil cylinders, and particularly relates to a hydraulic system for controlling an oil cylinder.

Background

In a hydraulic system in the field of ships, control over various output-type devices, such as cylinders, motors, and the like, can be realized by hydraulic oil.

Disclosure of Invention

The embodiment of the disclosure provides a hydraulic system for controlling an oil cylinder, which can still keep the oil cylinder to normally work under an emergency condition. The technical scheme is as follows:

the embodiment of the disclosure provides a hydraulic system for controlling an oil cylinder, which comprises an oil tank, a hydraulic pump, an oil cylinder assembly and a control assembly;

an oil outlet of the oil tank is communicated with an oil inlet of the hydraulic pump;

the oil cylinder assembly comprises a first three-position four-way reversing valve, a first hydraulic control one-way valve, a second hydraulic control one-way valve and an oil cylinder, wherein an oil inlet of the first three-position four-way reversing valve is communicated with an oil outlet of the hydraulic pump, an oil return port of the first three-position four-way reversing valve is communicated with an oil return port of the oil tank, a first working oil port of the first three-position four-way reversing valve is respectively communicated with an oil inlet of the first hydraulic control one-way valve and a control oil port of the second hydraulic control one-way valve, a second working oil port of the first three-position four-way reversing valve is respectively communicated with a control oil port of the first hydraulic control one-way valve and an oil inlet of the second hydraulic control one-way valve, an oil outlet of the first hydraulic control one-way valve is communicated with a rod cavity of the oil cylinder, and;

the control assembly comprises a first reversing valve, a second reversing valve, an energy accumulator and an overflow valve, a first oil port of the first reversing valve is communicated with an oil outlet of the hydraulic pump, a second oil port of the first reversing valve is communicated with the energy accumulator, an oil inlet of the overflow valve is communicated with the oil outlet of the hydraulic pump and a first control oil port of the overflow valve respectively, an oil outlet of the overflow valve is communicated with an oil return port of the oil tank, a second control oil port of the overflow valve is communicated with the first oil port of the second reversing valve, and a second oil port of the second reversing valve is communicated with the energy accumulator.

Optionally, the hydraulic system further includes an oil cylinder control assembly, the oil cylinder control assembly includes an electromagnetic directional valve, a third hydraulic control check valve and a fourth hydraulic control check valve, a first oil port of the electromagnetic directional valve is communicated with the energy accumulator, a second oil port of the electromagnetic directional valve is communicated with a control oil port of the third hydraulic control check valve, an oil return port of the electromagnetic directional valve is communicated with an oil return port of the oil tank, an oil outlet of the third hydraulic control check valve is communicated with the energy accumulator, an oil inlet of the third hydraulic control check valve is communicated with a rod cavity of the oil cylinder, an oil outlet of the fourth hydraulic control check valve is communicated with a rodless cavity of the oil cylinder, an oil inlet of the fourth hydraulic control check valve is communicated with an oil return port of the oil tank, and a control oil port of the fourth hydraulic control check valve is communicated with an oil inlet of the third hydraulic control check valve.

Optionally, the hydraulic system further includes an oil drainage assembly, the oil drainage assembly includes a fifth hydraulic control one-way valve and a second three-position four-way reversing valve, an oil outlet of the fifth hydraulic control one-way valve is communicated with an oil inlet of the third hydraulic control one-way valve, an oil inlet of the fifth hydraulic control one-way valve is communicated with a second working oil port of the second three-position four-way reversing valve, a control oil port of the fifth hydraulic control one-way valve is communicated with a first working oil port of the second three-position four-way reversing valve, an oil inlet of the second three-position four-way reversing valve is communicated with a first oil port of the first reversing valve, and an oil return port of the second three-position four-way reversing valve is communicated with an oil return port of the oil.

Optionally, the oil drainage assembly further comprises a first check valve, an oil inlet of the first check valve is communicated with an oil inlet of the third hydraulic control check valve, and an oil outlet of the first check valve is communicated with the rod cavity of the oil cylinder.

Optionally, the hydraulic system includes a second check valve, an oil inlet of the second check valve is communicated with an oil outlet of the hydraulic pump, and an oil outlet of the second check valve is communicated with an oil inlet of the first three-position four-way reversing valve.

Optionally, the hydraulic system includes a third check valve, an oil inlet of the third check valve is communicated with an oil outlet of the hydraulic pump, and an oil outlet of the third check valve is communicated with the first oil port of the first reversing valve.

Optionally, the hydraulic system further includes a filter, an oil inlet of the filter is communicated with an oil outlet of the hydraulic pump, and an oil outlet of the filter is communicated with an oil inlet of the first three-position four-way reversing valve.

Optionally, the hydraulic system further comprises a safety valve, an oil inlet of the safety valve is communicated with an oil outlet of the hydraulic pump, an oil outlet of the safety valve is communicated with an oil return port of the oil tank, and a control oil port of the safety valve is communicated with an oil inlet of the safety valve.

Optionally, the hydraulic system further includes an exhaust valve, and the exhaust valve is communicated between an oil return port of the first three-position four-way reversing valve and an oil return port of the oil tank.

Optionally, the hydraulic system further includes a pressure gauge interposed between an oil outlet of the hydraulic pump and an oil inlet of the first three-position four-way reversing valve.

The technical scheme provided by the embodiment of the disclosure has the following beneficial effects:

for the hydraulic system for controlling the oil cylinder provided by the embodiment of the disclosure, under a normal working condition, when the valve core of the first three-position four-way reversing valve is arranged at the right position, hydraulic oil sequentially passes through the hydraulic pump, the oil inlet of the first three-position four-way reversing valve, the first working oil port of the first three-position four-way reversing valve, the oil inlet of the first hydraulic control one-way valve, the oil outlet of the first hydraulic control one-way valve and the rod cavity of the oil cylinder, so that the piston rod of the oil cylinder retracts. Due to the retraction of the piston rod, hydraulic oil in the rodless cavity of the oil cylinder sequentially passes through the oil outlet of the second hydraulic control one-way valve, the oil inlet of the second hydraulic control one-way valve, the second working oil port of the first three-position four-way reversing valve and the oil return port of the first three-position four-way reversing valve, and finally returns to the oil tank.

When the valve core of the first three-position four-way reversing valve is arranged at the left position, hydraulic oil sequentially flows through the hydraulic pump, the oil inlet of the first three-position four-way reversing valve, the second working oil port of the first three-position four-way reversing valve, the oil inlet of the second hydraulic control one-way valve, the oil outlet of the second hydraulic control one-way valve and the rodless cavity of the oil cylinder, so that the piston rod of the oil cylinder extends out. Due to the fact that the piston rod extends out, hydraulic oil in a rod cavity of the oil cylinder sequentially passes through an oil outlet of the first hydraulic control one-way valve, an oil inlet of the first hydraulic control one-way valve, a first working oil port of the first three-position four-way reversing valve and an oil return port of the first three-position four-way reversing valve, and finally returns to the oil tank. And the rest is done in turn, thereby realizing the reciprocating work of the oil cylinder.

And under the normal operating mode, the valve cores of the first reversing valve and the second reversing valve are arranged at the right position, the first oil port of the first reversing valve is communicated with the second oil port of the first reversing valve, the first oil port of the second reversing valve is not communicated with the second oil port of the second reversing valve, and hydraulic oil can enter the energy accumulator through the first reversing valve so as to charge the energy accumulator. In addition, the overflow valve is communicated between an oil outlet of the hydraulic pump and an oil inlet of the oil tank, the opening pressure of the overflow valve is P1 (namely spring pressure), and the hydraulic pressure in the energy accumulator and the hydraulic system is normal pressure P1, so that the load and the load of the oil cylinder are P1 at the moment, and the oil cylinder works normally.

In an emergency situation, the load of the cylinder increases. And at this moment, the valve cores of the first reversing valve and the second reversing valve are arranged on the left, the first oil port of the first reversing valve is not communicated with the second oil port of the first reversing valve, the first oil port of the second reversing valve is communicated with the second oil port of the second reversing valve, hydraulic oil pressure (P1) in the energy accumulator can flow into the second control oil port of the overflow valve through the second reversing valve, on the basis of original spring pressure, the opening pressure of the overflow valve becomes 2P1, the hydraulic pressure in the hydraulic system is 2P1, namely emergency pressure, so that the output load of the oil cylinder is increased, the load of the oil cylinder is larger than that of the oil cylinder, and the oil cylinder can continuously keep working.

That is to say, the hydraulic system for cylinder control that this disclosure provided can increase the cracking pressure of overflow valve to increase the load of hydro-cylinder, so that the hydro-cylinder still can keep working under the emergency situation.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present disclosure, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a hydraulic system for controlling a cylinder according to an embodiment of the present disclosure.

The symbols in the drawings represent the following meanings:

1. an oil tank;

2. a hydraulic pump;

3. an oil cylinder assembly; 31. a first three-position four-way reversing valve; 32. a first hydraulic control check valve; 33. a second hydraulic control one-way valve; 34. an oil cylinder;

4. a control component; 41. a first direction changing valve; 42. a second directional control valve; 43. an accumulator; 44. an overflow valve;

5. a cylinder control assembly; 51. an electromagnetic directional valve; 52. a third hydraulic control check valve; 53. a fourth hydraulic control check valve;

6. an oil drainage assembly; 61. a fifth hydraulic control check valve; 62. a second three-position four-way reversing valve;

7. a first check valve; 8. a second one-way valve; 9. a third check valve; 10. a filter; 11. a safety valve; 12. an exhaust valve; 13. and a pressure gauge.

Detailed Description

To make the objects, technical solutions and advantages of the present disclosure more apparent, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of a hydraulic system for controlling a cylinder according to an embodiment of the present disclosure, and as shown in fig. 1, the hydraulic system includes an oil tank 1, a hydraulic pump 2, a cylinder assembly 3, and a control assembly 4.

An oil outlet of the oil tank 1 is communicated with an oil inlet of the hydraulic pump 2.

The oil cylinder assembly 3 comprises a first three-position four-way reversing valve 31, a first hydraulic control one-way valve 32, a second hydraulic control one-way valve 33 and an oil cylinder 34, an oil inlet p of the first three-position four-way reversing valve 31 is communicated with an oil outlet of the hydraulic pump 2, an oil return port t of the first three-position four-way reversing valve 31 is communicated with an oil return port of the oil tank 1, a first working oil port a of the first three-position four-way reversing valve 31 is respectively communicated with an oil inlet b of the first hydraulic control one-way valve 32 and a control oil port c of the second hydraulic control one-way valve 33, a second working oil port b of the first three-position four-way reversing valve 31 is respectively communicated with the control oil port c of the first hydraulic control one-way valve 32 and an oil inlet b of the second hydraulic control one-way valve 33, an oil outlet a of the first hydraulic control one-way valve 32 is communicated with a rod cavity.

The control assembly 4 comprises a first reversing valve 41, a second reversing valve 42, an energy accumulator 43 and an overflow valve 44, a first oil port a of the first reversing valve 41 is communicated with an oil outlet of the hydraulic pump 2, a second oil port b of the first reversing valve 41 is communicated with the energy accumulator 43, an oil inlet a of the overflow valve 44 is respectively communicated with the oil outlet of the hydraulic pump 2 and a first control oil port b of the overflow valve 44, an oil outlet d of the overflow valve 44 is communicated with an oil return port of the oil tank 1, a second control oil port c of the overflow valve 44 is communicated with a first oil port a of the second reversing valve 42, and a second oil port b of the second reversing valve 42 is communicated with the energy accumulator 43.

For the hydraulic system for controlling the oil cylinder provided by the embodiment of the disclosure, under the normal working condition:

when the valve core of the first three-position four-way reversing valve 31 is arranged at the right position, hydraulic oil passes through the hydraulic pump 2, the oil inlet p of the first three-position four-way reversing valve 31, the first working oil port a of the first three-position four-way reversing valve 31, the oil inlet b of the first hydraulic control one-way valve 32, the oil outlet a of the first hydraulic control one-way valve 32 and the rod cavity of the oil cylinder 34 in sequence, so that the piston rod of the oil cylinder 34 retracts. Due to retraction of the piston rod, hydraulic oil in the rodless cavity of the oil cylinder 34 passes through the oil outlet a of the second hydraulic control one-way valve 33, the oil inlet b of the second hydraulic control one-way valve 33, the second working oil port b of the first three-position four-way reversing valve 31 and the oil return port t of the first three-position four-way reversing valve 31 in sequence, and finally returns to the oil tank 1.

When the valve core of the first three-position four-way reversing valve 31 is arranged at the left position, the hydraulic oil is sequentially fed into the hydraulic pump 2, the oil inlet p of the first three-position four-way reversing valve 31, the second working oil port b of the first three-position four-way reversing valve 31, the oil inlet b of the second hydraulic control one-way valve 33, the oil outlet a of the second hydraulic control one-way valve 33 and the rodless cavity of the oil cylinder 34, so that the piston rod of the oil cylinder 34 extends out. Due to the extension of the piston rod, the hydraulic oil in the rod cavity of the oil cylinder 34 passes through the oil outlet a of the first hydraulic control one-way valve 32, the oil inlet b of the first hydraulic control one-way valve 32, the first working oil port a of the first three-position four-way reversing valve 31 and the oil return port t of the first three-position four-way reversing valve 31 in sequence, and finally returns to the oil tank 1. And the like, thereby realizing the reciprocating work of the oil cylinder 34.

And under the normal working condition, the valve cores of the first directional valve 41 and the second directional valve 42 are both arranged at the right position, the first oil port a of the first directional valve 41 is communicated with the second oil port b thereof, the first oil port a of the second directional valve 42 is not communicated with the second oil port b thereof, and the hydraulic oil can pass through the first directional valve 41 and enter the energy accumulator 43, so that the energy accumulator 43 is pressurized. In addition, the overflow valve 44 is communicated between the oil outlet of the hydraulic pump 2 and the oil inlet of the oil tank 1, the opening pressure of the overflow valve 44 is P1 (namely, spring pressure), and at the moment, the hydraulic pressure inside the accumulator 43 and the hydraulic system is normal pressure P1, then the load and the load of the oil cylinder 34 are both P1, and the oil cylinder 34 works normally.

In an emergency situation, the load of the cylinder 34 increases. At this time, the valve cores of the first direction valve 41 and the second direction valve 42 are both arranged at the left position, the first oil port a of the first direction valve 41 is not communicated with the second oil port b of the first direction valve, the first oil port a of the second direction valve 42 is communicated with the second oil port b of the second direction valve, the hydraulic oil pressure (P1) in the energy accumulator 43 can flow into the second control oil port c of the overflow valve 44 through the second direction valve 42, on the basis of the original spring pressure, the opening pressure of the overflow valve 44 is changed into 2P1, the hydraulic pressure inside the hydraulic system is 2P1, namely, the emergency pressure, so that the output load of the oil cylinder 34 is increased, the load of the oil cylinder 34 is larger than the load of the oil cylinder 34, and the oil cylinder 34 can continuously keep working.

That is, the present disclosure provides a hydraulic system for cylinder control that can increase the opening pressure of the relief valve 44, thereby increasing the load of the cylinder 34, so that the cylinder 34 can still maintain operation in an emergency situation.

In the present embodiment, both the first direction valve 41 and the second direction valve 42 may be electromagnetic direction valves, thereby facilitating better control of the position of the spool.

With continued reference to fig. 1, the hydraulic system further includes a cylinder control assembly 5, the cylinder control assembly 5 includes an electromagnetic directional valve 51, a third pilot-controlled check valve 52 and a fourth pilot-controlled check valve 53, a first oil port a of the electromagnetic directional valve 51 is communicated with the energy accumulator 43, a second oil port b of the electromagnetic directional valve 51 is communicated with a control oil port c of the third pilot-controlled check valve 52, an oil return port c of the electromagnetic directional valve 51 is communicated with an oil return port of the oil tank 1, an oil outlet a of the third pilot-controlled check valve 52 is communicated with the energy accumulator 43, an oil inlet b of the third pilot-controlled check valve 52 is communicated with a rod cavity of the cylinder 34, an oil outlet a of the fourth pilot-controlled check valve 53 is communicated with a rodless cavity of the cylinder 34, an oil inlet b of the fourth pilot-controlled check valve 53 is communicated with an oil port of the oil tank 1, and a control oil port c of the fourth pilot-controlled check valve 53 is.

In the above embodiment, when the electromagnetic directional valve 51 is powered (the valve core is disposed at the upper position), the first oil port a of the electromagnetic directional valve 51 is communicated with the energy accumulator 43, and the second oil port b of the electromagnetic directional valve 51 is communicated with the control oil port c of the third pilot-controlled check valve 52, so that the hydraulic oil of the energy accumulator 43 can communicate the oil outlet a and the oil inlet b of the third pilot-controlled check valve 52, and the hydraulic oil in the energy accumulator 43 flows into the rod cavity of the oil cylinder 34 through the third pilot-controlled check valve 52, and the piston rod retracts. That is, the control process may function to retract the piston rod in the event of a failure of the first three-position, four-way reversing valve 31.

In addition, the control oil port c of the fourth pilot-controlled check valve 53 is communicated with the oil inlet b of the third pilot-controlled check valve 52, and the hydraulic oil flowing to the oil inlet b of the third pilot-controlled check valve 52 from the energy accumulator 43 can make the oil outlet a of the fourth pilot-controlled check valve 53 communicated with the oil inlet b, so that when the piston rod retracts, the hydraulic oil in the rodless cavity of the oil cylinder 34 flows back to the oil tank 1 through the fourth pilot-controlled check valve 53.

It should be noted that, when the electromagnetic directional valve 51 is de-energized (the spool is set to the lower position), the third pilot-operated check valve 52 and the fourth pilot-operated check valve 53 both maintain the open-circuit state, and the piston rod of the oil cylinder 34 is not retracted. In addition, the electromagnetic directional valve 51 can realize remote control, thereby realizing the remote control of the oil cylinder 34.

Optionally, the hydraulic system further includes an oil drainage assembly 6, the oil drainage assembly 6 includes a fifth hydraulic control one-way valve 61 and a second three-position four-way reversing valve 62, an oil outlet a of the fifth hydraulic control one-way valve 61 is communicated with an oil inlet b of the third hydraulic control one-way valve 52, an oil inlet b of the fifth hydraulic control one-way valve 61 is communicated with a second working oil port b of the second three-position four-way reversing valve 62, a control oil port c of the fifth hydraulic control one-way valve 61 is communicated with a first working oil port a of the second three-position four-way reversing valve 62, an oil inlet p of the second three-position four-way reversing valve 62 is communicated with a first oil port a of the first reversing valve 41, and an oil return port t of the second three-position four-way reversing valve 62 is.

In the above embodiment, on the one hand, when the spool of the first reversing valve 41 is set to the right position, the electromagnetic reversing valve 51 is powered on, and the spool of the second three-position four-way reversing valve 62 is set to the right position, at this time, the first oil port a and the second oil port b of the first reversing valve 41 are communicated, so that the control oil port c of the fifth hydraulic control one-way valve 61 is communicated with the energy accumulator 43 through the first working oil port a of the second three-position four-way reversing valve 62 and the oil inlet p of the second three-position four-way reversing valve 62, and the pressure oil of the energy accumulator 43 can enable the oil outlet a and the oil inlet b of the fifth hydraulic control one-way valve 61 to be communicated. Then, the hydraulic oil of the energy accumulator 43 sequentially passes through the third hydraulic control one-way valve 52, the oil outlet a of the fifth hydraulic control one-way valve 61, the oil inlet b of the fifth hydraulic control one-way valve 61, the second working oil port b of the second three-position four-way reversing valve 62 and the oil return port t of the second three-position four-way reversing valve 62, and thus flows back into the oil tank 1, and the effect of discharging the flow of the energy accumulator 43 can be achieved.

On the other hand, when the spool of the first directional valve 41 is set to the right position, the electromagnetic directional valve 51 is de-energized, and the spool of the second three-position four-way directional valve 62 is set to the left position, the first oil port a and the second oil port b of the electromagnetic directional valve 51 are not communicated, so that the electromagnetic directional valve 51 is opened. At this time, the first oil port a of the first reversing valve 41 is communicated with the second oil port b, and the hydraulic oil of the energy accumulator 43 can sequentially pass through the first reversing valve 41, the oil inlet p of the second three-position four-way reversing valve 62, the second working oil port b of the second three-position four-way reversing valve 62, the oil inlet b of the fifth hydraulic control one-way valve 61, and the oil outlet a of the fifth hydraulic control one-way valve 61, so as to finally enter the rod cavity of the oil cylinder 34, so that the piston rod of the oil cylinder 34 can still be recovered through the fifth hydraulic control one-way valve 61 and the second three-position four-way reversing valve 62 and through manual control.

Optionally, the oil drainage assembly 6 further includes a first check valve 7, an oil inlet of the first check valve 7 is communicated with an oil inlet b of the third pilot-controlled check valve 52, and an oil outlet of the first check valve 7 is communicated with the rod cavity of the oil cylinder 34.

In the above embodiment, the first check valve 7 has a certain cracking pressure so that when the accumulator 43 is draining, the pressure oil in the accumulator 43 does not pass through the first check valve 7 but can only flow back to the tank 1 from the fifth pilot-operated check valve 61.

Illustratively, the ball valve right end of the first check valve 7 is provided with a spring, so that the first check valve 7 can be opened only under a certain pressure.

With continued reference to fig. 1, the hydraulic system includes a second check valve 8, an oil inlet of the second check valve 8 is communicated with an oil outlet of the hydraulic pump 2, and an oil outlet of the second check valve 8 is communicated with an oil inlet p of the first three-position four-way reversing valve 31.

In the above embodiment, the second check valve 8 can prevent the backflow of the pressure oil that enters the first three-position four-way selector valve 31.

Optionally, the hydraulic system includes a third check valve 9, an oil inlet of the third check valve 9 is communicated with an oil outlet of the hydraulic pump 2, and an oil outlet of the third check valve 9 is communicated with the first oil port a of the first directional valve 41.

In the above embodiment, the third check valve 9 can prevent the backflow of the pressure oil entering the first direction changing valve 41.

Optionally, the hydraulic system further includes a filter 10, an oil inlet of the filter 10 is communicated with an oil outlet of the hydraulic pump 2, and an oil outlet of the filter 10 is communicated with an oil inlet p of the first three-position four-way reversing valve 31.

In the above embodiment, the filter 10 functions to filter the hydraulic oil that enters the first three-position four-way selector valve 31, thereby preventing clogging of the first three-position four-way selector valve 31.

It should be noted that a blockage safety alarm (not shown) may be disposed between the oil inlet and the oil outlet of the filter 10, and the blockage safety alarm is used for detecting the on-off condition of the filter 10 and monitoring the filter 10.

Optionally, the hydraulic system further includes a safety valve 11, an oil inlet of the safety valve 11 is communicated with an oil outlet of the hydraulic pump 2, an oil outlet of the safety valve 11 is communicated with an oil return port of the oil tank 1, and a control oil port of the safety valve 11 is communicated with an oil inlet of the safety valve 11.

In the above embodiment, the safety valve 11 plays a role of pressure limiting protection for the hydraulic system, and prevents the danger caused by the over-high pressure of the oil outlet of the oil tank 1.

Optionally, the hydraulic system further comprises an exhaust valve 12, and the exhaust valve 12 is communicated between the oil return port t of the first three-position four-way reversing valve 31 and the oil return port of the oil tank 1.

In the above embodiment, the exhaust valve 12 plays a role of exhausting the hydraulic oil in the line of the hydraulic system, thereby preventing damage of the hydraulic pump 2 and the valves.

Optionally, the hydraulic system further includes a pressure gauge 13, and the pressure gauge 13 is inserted between an oil outlet of the hydraulic pump 2 and an oil inlet p of the first three-position four-way reversing valve 31.

In the above embodiment, the pressure gauge 13 may monitor the pressure of the hydraulic system in real time, and may timely cope with the situation when the pressure of the hydraulic system is too high.

Illustratively, when it is desired to monitor the pressure of the hydraulic system, this is done by directly reading the pressure gauge 13.

The working principle of the hydraulic system of the present disclosure is briefly explained as follows:

under a normal working condition, when the valve core of the first three-position four-way reversing valve 31 is arranged at the right position, hydraulic oil sequentially passes through the hydraulic pump 2, the oil inlet p of the first three-position four-way reversing valve 31, the first working oil port a of the first three-position four-way reversing valve 31, the oil inlet b of the first hydraulic control one-way valve 32, the oil outlet a of the first hydraulic control one-way valve 32 and the rod cavity of the oil cylinder 34, so that the piston rod of the oil cylinder 34 retracts. Due to retraction of the piston rod, hydraulic oil in the rodless cavity of the oil cylinder 34 passes through the oil outlet a of the second hydraulic control one-way valve 33, the oil inlet b of the second hydraulic control one-way valve 33, the second working oil port b of the first three-position four-way reversing valve 31 and the oil return port t of the first three-position four-way reversing valve 31 in sequence, and finally returns to the oil tank 1.

When the valve core of the first three-position four-way reversing valve 31 is arranged at the left position, the hydraulic oil is sequentially fed into the hydraulic pump 2, the oil inlet p of the first three-position four-way reversing valve 31, the second working oil port b of the first three-position four-way reversing valve 31, the oil inlet b of the second hydraulic control one-way valve 33, the oil outlet a of the second hydraulic control one-way valve 33 and the rodless cavity of the oil cylinder 34, so that the piston rod of the oil cylinder 34 extends out. Due to the extension of the piston rod, the hydraulic oil in the rod cavity of the oil cylinder 34 passes through the oil outlet a of the first hydraulic control one-way valve 32, the oil inlet b of the first hydraulic control one-way valve 32, the first working oil port a of the first three-position four-way reversing valve 31 and the oil return port t of the first three-position four-way reversing valve 31 in sequence, and finally returns to the oil tank 1. And the like, thereby realizing the reciprocating work of the oil cylinder 34.

And under the normal working condition, the valve cores of the first directional control valve 41 and the second directional control valve are both arranged at the right position, the first oil port a of the first directional control valve 41 is communicated with the second oil port b thereof, the first oil port a of the second directional control valve 42 is not communicated with the second oil port b thereof, and the hydraulic oil can pass through the first directional control valve 41 and enter the energy accumulator 43, so that the energy accumulator 43 is pressurized. In addition, the overflow valve 44 is communicated between the oil outlet of the hydraulic pump 2 and the oil inlet of the oil tank 1, the opening pressure of the overflow valve 44 is P1 (namely, spring pressure), and at the moment, the hydraulic pressure inside the accumulator 43 and the hydraulic system is normal pressure P1, then the load and the load of the oil cylinder 34 are both P1, and the oil cylinder 34 works normally.

In an emergency situation, the load of the cylinder 34 increases. At this time, the valve cores of the first direction valve 41 and the second direction valve 42 are both arranged at the left position, the first oil port a of the first direction valve 41 is not communicated with the second oil port b of the first direction valve, the first oil port a of the second direction valve 42 is communicated with the second oil port b of the second direction valve, the hydraulic oil pressure (P1) in the energy accumulator 43 can flow into the second control oil port c of the overflow valve 44 through the second direction valve 42, on the basis of the original spring pressure, the opening pressure of the overflow valve 44 is changed into 2P1, the hydraulic pressure inside the hydraulic system is 2P1, namely, the emergency pressure, so that the output load of the oil cylinder 34 is increased, the load of the oil cylinder 34 is larger than the load of the oil cylinder 34, and the oil cylinder 34 can continuously keep working.

That is, the present disclosure provides a hydraulic system for cylinder control that can increase the opening pressure of the relief valve 44, thereby increasing the load of the cylinder 34, so that the cylinder 34 can still maintain operation in an emergency situation.

The above description is intended to be exemplary only and not to limit the present disclosure, and any modification, equivalent replacement, or improvement made without departing from the spirit and scope of the present disclosure is to be considered as the same as the present disclosure.