CN211231080U

CN211231080U - Double-balance valve and hydraulic control system

Info

Publication number: CN211231080U
Application number: CN201921571615.4U
Authority: CN
Inventors: 孔红梅; 陈智星; 孔晨菁
Original assignee: Shanghai Longline Mechanical And Electrical Equipment Co ltd
Current assignee: Shanghai Longline Mechanical And Electrical Equipment Co ltd
Priority date: 2019-09-20
Filing date: 2019-09-20
Publication date: 2020-08-11
Anticipated expiration: 2029-09-20

Abstract

A dual balanced valve and hydraulic control system, the dual balanced valve comprising: the oil duct comprises a first oil duct, a second oil duct and a connecting oil duct, the first oil duct is connected with a first control oil port and a second control oil port, the second oil duct is connected with a first auxiliary working oil port and a second auxiliary working oil port, the connecting oil duct is provided with a first end part and a second end part, the first end part is positioned on the first oil duct, the second end part is positioned on the second oil duct, and the first oil duct, the second oil duct and the connecting oil duct are communicated; the first damping piece is arranged on the second oil duct and is positioned between the second end part and the first auxiliary working oil port; the second damping piece is arranged on the second oil duct and is located between the second end portion and the second auxiliary working oil port. The utility model discloses help reducing the guide ratio of double balance valve to improve the steadiness of pneumatic cylinder control load, reduce the risk that the pneumatic cylinder takes place to shake.

Description

Double-balance valve and hydraulic control system

Technical Field

The utility model relates to a hydraulic control technical field especially relates to a double balance valve and hydraulic control system.

Background

In the field of engineering machinery, the transmission mode of most working mechanisms is hydraulic transmission, that is, an engine drives a hydraulic pump to provide hydraulic energy, and a hydraulic control valve provides flow and maximum pressure for supporting actions for a hydraulic cylinder or a hydraulic motor, so that actions of mechanical equipment are realized.

Under the condition of negative load (the load direction is the same as the movement direction and the force direction of the hydraulic actuator), because the oil returned by the actuator does not have enough back pressure, the phenomenon of 'stalling' is often generated, and the phenomenon is extremely dangerous for mechanical equipment. The current common solution is to install a balance valve on the actuator, and generally use the principle of a pressure valve to provide a back pressure slightly larger than the load to the actuator to counteract the load effect. When the actuating mechanism needs to act, small pressure can be provided for the pilot control oil port to open the balance valve, and energy loss caused by back pressure is reduced. Meanwhile, the balance valve can simultaneously realize the functions of pressure maintaining and positioning.

When the actuator is possible to act as a load in both directions, a double balanced valve is often used, so that the actuator can achieve the above function regardless of the direction in which the actuator moves.

However, the conventional double balance valve has a high pilot ratio, and is likely to cause a phenomenon in which the hydraulic cylinder shakes.

SUMMERY OF THE UTILITY MODEL

The utility model provides a problem provide a double balance valve and hydraulic control system helps reducing double balance valve's guide's ratio to improve the steadiness of pneumatic cylinder control load, reduce the risk that the pneumatic cylinder took place to shake.

In order to solve the above problem, the utility model provides a double balance valve, include: the first balance valve comprises a first pressure valve and a first check valve, the first pressure valve is provided with a first main working oil port, a first auxiliary working oil port and a first control oil port, one end of the first check valve is connected with the first main working oil port, and the other end of the first check valve is connected with the first auxiliary working oil port; the second balance valve comprises a second pressure valve and a second check valve, the second pressure valve is provided with a second main working oil port, a second auxiliary working oil port and a second control oil port, one end of the second check valve is connected with the second main working oil port, and the other end of the second check valve is connected with the second auxiliary working oil port; the oil duct comprises a first oil duct, a second oil duct and a connecting oil duct, the first oil duct is connected with the first control oil port and the second control oil port, the second oil duct is connected with the first auxiliary working oil port and the second auxiliary working oil port, the connecting oil duct is provided with a first end part and a second end part, the first end part is positioned on the first oil duct, the second end part is positioned on the second oil duct, and the first oil duct, the second oil duct and the connecting oil duct are communicated; the first damping piece is arranged on the second oil duct and is positioned between the second end part and the first auxiliary working oil port; and the second damping piece is arranged on the second oil duct, and is positioned between the second end part and the second auxiliary working oil port.

Optionally, the damping coefficient of the second damping member is greater than, equal to, or less than the damping coefficient of the first damping member.

Optionally, the first check valve communicates the first auxiliary working oil port to the oil path of the first main working oil port, and the second check valve communicates the second auxiliary working oil port to the oil path of the second main working oil port.

Optionally, the first pressure valve further has a first load oil port, and the second pressure valve further has a second load oil port; the oil passage further includes: the first load oil duct is connected with the first load oil port and the first main working oil port, and the second load oil duct is connected with the second load oil port and the second main working oil port.

Optionally, the first pressure valve has a first opening position and a first closing position, the first load port has a first valve core opening oil pressure, and when the oil pressure of the first load port reaches the first valve core opening oil pressure, the first pressure valve is switched from the first closing position to the first opening position; the second pressure valve is provided with a second opening position and a second closing position, the second load oil port is provided with a second valve core opening oil pressure, and when the oil pressure of the second load oil port reaches the second valve core opening oil pressure, the second pressure valve is switched to the second opening position from the second closing position.

Optionally, the first control port has a first pilot opening oil pressure, and when the oil pressure of the first control port reaches the first pilot opening oil pressure, the first pressure valve is switched from a first closed position to a first open position; the second pressure valve is provided with a second opening position and a second closing position, the second control oil port is provided with a second pilot opening oil pressure, and when the oil pressure of the second control oil port reaches the second pilot opening oil pressure, the second pressure valve is switched to the second opening position from the second closing position.

Optionally, the first pressure valve further has a first spring cavity oil drain port, and the second pressure valve further has a second spring cavity oil drain port; the oil passage further includes: the first spring cavity oil drainage channel is connected with the first spring cavity oil drainage port and the first auxiliary working oil port, and the second spring cavity oil drainage channel is connected with the second spring cavity oil drainage port and the second auxiliary working oil port.

Correspondingly, the utility model discloses still provide a hydraulic control system including above the double balance valve.

Optionally, the hydraulic control system further includes: the hydraulic cylinder comprises a cylinder barrel and a piston rod, the piston rod is suitable for reciprocating, the piston rod is provided with a load end and a piston which are opposite, the load end is exposed out of the hydraulic cylinder, the piston divides an inner cavity of the cylinder barrel into a first cavity and a second cavity, and the second cavity is located between the piston and the load end.

Optionally, the hydraulic control system further includes: the oil duct still includes: the first oil return duct is connected with the first auxiliary working oil port and the oil tank, and the second oil return duct is connected with the second auxiliary working oil port and the oil tank.

Optionally, the double balanced valve comprises: the main valve block is provided with a cavity which penetrates through two ends; the first pressure valve includes: the first valve core assembly is positioned in the cavity, and the telescopic direction of the first valve core assembly is along the axial direction of the cavity; the first sleeve is positioned at one end of the main valve block, one end of the first sleeve extends into the cavity, and the other end of the first sleeve protrudes out of the cavity along the axis direction of the cavity; the first main spring assembly is located in the first sleeve and comprises a first spring seat end and a first spring, the first spring seat end is located between the first valve core assembly and the first spring, and the first spring seat end is abutted to the first valve core assembly under the action of elastic force of the first spring.

Optionally, the second pressure valve comprises: the second valve core assembly is positioned in the cavity, the telescopic direction of the second valve core assembly is along the axial direction of the cavity, and one end of the second valve core assembly is opposite to one end of the first valve core assembly; the second sleeve is positioned at the other end of the main valve block opposite to the first sleeve, one end of the second sleeve extends into the cavity, and the other end of the second sleeve protrudes out of the cavity along the axis direction of the cavity; the second main spring assembly is located in the second sleeve and comprises a second spring seat end and a third spring, the second spring seat end is located between the second valve spool assembly and the third spring, and under the action of elastic force of the third spring, the second spring seat end is abutted to the second valve spool assembly.

Optionally, when the first chamber is communicated with the second main working oil port, and the second chamber is communicated with the first main working oil port, the double-balanced valve further includes: the first limiting gasket is fixedly arranged on the first spring seat end, and is positioned between the first spring seat end and the first spring.

Optionally, when the first chamber is communicated with the first main working oil port, and the second chamber is communicated with the second main working oil port, the double-balanced valve further includes: and the second limiting gasket is fixedly arranged on the second spring seat end and is positioned between the second spring seat end and the third spring.

Compared with the prior art, the technical scheme of the utility model have following advantage:

the double balanced valve includes: the first balance valve, the second balance valve, the oil duct, the second damping member and the first damping member. Work as first vice working fluid port conduct the fuel feeding mouth of two balanced valves, the vice working fluid port of second is as during the oil return mouth of two balanced valves, utilize alone the oil pressure of first vice working fluid port department switches the second pressure valve, because part the fluid warp of first vice working fluid port department connect the oil duct carry extremely the second control hydraulic fluid port, the rest the fluid of first vice working fluid port department is followed always the second oil duct is carried to second vice working fluid port department and is returned oil, consequently the oil pressure of first vice working fluid port department is higher than the oil pressure of second control hydraulic fluid port department, in order to promote the guide's oil pressure of first vice working fluid port department, the guide's ratio of two balanced valves with the oil pressure of first vice working fluid port department is the inverse ratio of leading, thereby can reduce the guide's ratio of two balanced valves. The second damping piece can divide the oil pressure of the second control oil port in a shunting manner and maintain the oil pressure of the first auxiliary working oil port.

Correspondingly, work as the vice work hydraulic fluid port of second conduct the fuel feed port of two balanced valves, first vice work hydraulic fluid port conduct during the oil return port of two balanced valves, utilize alone the oil pressure of the vice work hydraulic fluid port department of second switches during the first pressure valve, because only part the fluid warp of the vice work hydraulic fluid port department of second connects the oil duct carry extremely first control hydraulic fluid port, consequently the oil pressure of the vice work hydraulic fluid port department of second is higher than the oil pressure of first control hydraulic fluid port department, in order to promote the guide's oil pressure of the vice work hydraulic fluid port department of second, the guide ratio of two balanced valves with the guide's oil pressure of the vice work hydraulic fluid port department of second is the inverse ratio, thereby can reduce the guide ratio of two balanced valves. The first damping piece can divide the oil pressure of the first control oil port in a shunting manner and can maintain the oil pressure of the second auxiliary working oil port.

In summary, no matter the first auxiliary working oil port is used as the oil supply port of the double-balance valve and the second auxiliary working oil port is used as the oil return port of the double-balance valve, or the second auxiliary working oil port is used as the oil supply port of the double-balance valve, the first auxiliary working oil port is used as the oil return port of the double-balance valve, and the oil duct, the second damping member and the first damping member can play a role in reducing the pilot ratio of the double-balance valve, so that the stability of the hydraulic cylinder for controlling the load is improved, and the risk of shaking of the hydraulic cylinder is reduced.

In an alternative, when the first chamber is communicated with the second main working oil port, and the second chamber is communicated with the first main working oil port, the double balance valve further includes: first spacing gasket, first spacing gasket set firmly in first spring holder is served, and first spacing gasket is located first spring holder end with between the first spring, first spacing gasket can restrict first case subassembly is followed first telescopic axis direction court the maximum distance that the chamber says and remove helps reducing the maximum value of the opening size of first pair hydraulic fluid port for the warp the nominal flow of first pair hydraulic fluid port oil return reduces, further reduces first pair hydraulic fluid port step-down speed leads to the pneumatic cylinder to take place the risk of shake at the excessive speed.

In an alternative, when the first chamber is communicated with the first main working oil port, and the second chamber is communicated with the second main working oil port, the double balance valve further includes: the spacing gasket of second, the spacing gasket of second set firmly in the second spring holder is served, and the spacing gasket of second is located second spring holder end with between the third spring, the spacing gasket of second can restrict second valve core subassembly is followed the telescopic axis direction of second court the maximum distance that the chamber says and remove helps reducing the maximum value of the opening size of the vice hydraulic fluid port of second for the warp the nominal flow of the vice hydraulic fluid port of second oil return reduces, further reduces the vice hydraulic fluid port of second pressure reduction rate leads to the pneumatic cylinder to take place the risk of shake at the excessive speed.

Drawings

FIG. 1 is a hydraulic schematic of a double balanced valve;

fig. 2 is a hydraulic schematic diagram of a double balanced valve in an embodiment of the invention;

fig. 3 is a hydraulic schematic diagram of a hydraulic control system in an embodiment of the present invention;

FIG. 4 is a hydraulic schematic of a hydraulic control system in another embodiment of the present invention;

FIG. 5 is a schematic diagram of the structure of the double balanced valve shown in FIG. 2;

fig. 6 is an enlarged partial view of the double balanced valve shown in fig. 5.

Detailed Description

As is known from the background art, the pilot ratio of the prior art double balanced valves is high.

Now analyzing in connection with a double balanced valve 10, with reference to fig. 1, the double balanced valve 10 comprises: the first balance valve 21, the first balance valve 21 including a first pressure valve 31 and a first check valve 41, the first pressure valve 31 having a first main working port C1, a first sub working port V1, a first control port a1 and a first load port B1, the first check valve 41 connecting the first main working port C1 and the first sub working port V1; the second balance valve 22, the second balance valve 22 includes a second pressure valve 32 and a second check valve 42, the second pressure valve 32 has a second main working port C2, a second auxiliary working port V2, a second control port a2 and a second load port B2, and the second check valve 42 is connected to the second main working port C2 and the second auxiliary working port V2; oil passages including a first pilot oil passage 51, a second pilot oil passage 52, a first load oil passage 61, and a second load oil passage 62; the first pilot oil passage 51 is connected to the first sub-working port V1 and the second control port a 2; the second pilot oil passage 52 connects the second sub-working port V2 and the first control port a 1; the first load oil passage 61 connects the first load port B1 and the first main working port C1; the second load oil passage 62 connects the second load port B2 and the second main working port C2.

The first sub-working port V1 serves as an oil supply port of the double balance valve 10, and the second sub-working port V2 serves as an oil return port of the double balance valve 10. The first main working oil port C1 is communicated with an upper chamber of the hydraulic cylinder, and the second main working oil port C2 is communicated with a lower chamber of the hydraulic cylinder.

When the valve element of the second pressure valve 32 is opened by using the oil pressure of the second load port B2 alone, the minimum oil pressure of the second load port B2 is the valve element opening oil pressure. When the valve element of the second pressure valve 32 is opened by the oil from the first sub-working port V1 being fed to the second control port a2 along the first pilot oil passage 51, the minimum oil pressure of the second control port a2 is the pilot opening oil pressure. The geometric pilot ratio of the double balanced valve 10 is the area ratio of the second control port a2 to the second load port B2, and the pilot ratio is the ratio of the spool opening oil pressure to the pilot opening oil pressure.

The two balanced valve 10's guide's relative altitude for under the load operating mode (load direction of motion is the same with the oil pressure direction), first vice hydraulic fluid port V1 oil pressure easily passes through first guide oil duct 51 makes second pressure valve 32 case open, causes second main hydraulic fluid port C2 fluid is quick to be crossed second pressure valve 32 flows extremely the vice hydraulic fluid port V2 of second, and warp the vice hydraulic fluid port V2 oil return of second leads to the load of pneumatic cylinder to descend along with the piston rod fast, and causes the phenomenon of quick step-down takes place easily for first vice hydraulic fluid port V1. When the first sub-port V1 drops below the pilot opening oil pressure, the spool of the second pressure valve 32 suddenly closes. When the oil pressure of the first sub-working port V1 rises to the pilot opening oil pressure along with the oil filling in the upper chamber of the hydraulic cylinder, the second pressure valve 32 suddenly opens the spool. As described above, the spool of the second pressure valve 32 is repeatedly and rapidly switched between opening and closing, so that the hydraulic cylinder is easily shaken, and the smoothness of the load controlled by the hydraulic cylinder is affected.

In order to make the aforementioned objects, features and advantages of the present invention more comprehensible, embodiments accompanied with figures are described in detail below.

Referring to fig. 2, a dual balanced valve 100 includes: the first balance valve 210, the second balance valve 220, the oil passage, the second damping member 520, and the first damping member 510.

The first counter balance valve 210 includes a first pressure valve 211 and a first check valve 212. The first pressure valve 211 has a first main working port c1, a first sub working port v1, and a first control port a1, and one end of the first check valve 212 is connected to the first main working port c1, and the other end is connected to the first sub working port v 1.

In this embodiment, the first pressure valve 211 further has a first load port b 1.

In this embodiment, the first pressure valve 211 further has a first spring chamber oil release port e 1.

The second balance valve 220 includes a second pressure valve 221 and a second check valve 222, the second pressure valve 221 includes a second main working port c2, a second sub working port v2 and a second control port a2, one end of the second check valve 222 is connected to the second main working port c2, and the other end is connected to the second sub working port v 2.

In this embodiment, the second pressure valve 221 further has a second load port b 2.

In this embodiment, the second pressure valve 221 further has a second spring chamber oil release port e 2.

The oil passages include a first oil passage 310, a second oil passage 320 and a connecting oil passage 410, the first oil passage 310 is connected to the first control oil port a1 and the second control oil port a2, the second oil passage 320 is connected to the first sub-working oil port v1 and the second sub-working oil port v2, the connecting oil passage 410 has a first end 411 and a second end 412 which are opposite, the first end 411 is located on the first oil passage 310, the second end 412 is located on the second oil passage 320, and the first oil passage 310, the second oil passage 320 and the connecting oil passage 410 are communicated.

In this embodiment, the oil passage further includes: the first load oil passage 331 is connected to the first load oil port b1 and the first main working oil port c1, and the second load oil passage 332 is connected to the second load oil port b2 and the second main working oil port c 2.

In this embodiment, the oil passage further includes: the first spring cavity oil drainage channel 341 is connected with the first spring cavity oil drainage port e1 and the first sub-working port v1, and the second spring cavity oil drainage channel 342 is connected with the second spring cavity oil drainage port e2 and the second sub-working port v 2.

The first damping member 510 is disposed on the second oil passage 320, and the first damping member 510 is located between the second end 412 and the first sub-hydraulic port v 1.

The second damping member 520 is disposed on the second oil passage 320, and the second damping member 520 is located between the second end 412 and the second sub-working port v 2.

Referring to fig. 3, in a hydraulic control system 700 including the double balanced valve 100, the hydraulic control system 700 further includes: the hydraulic cylinder 600 comprises a cylinder 610 and a piston rod 620, the piston rod 620 is suitable for reciprocating, the piston rod 620 is provided with a load end 621 and a piston 622 which are opposite, the load end 621 is exposed out of the hydraulic cylinder 600, the piston 622 divides an inner cavity of the cylinder 610 into a first chamber 631 and a second chamber 632, and the second chamber 632 is located between the piston 622 and the load end 621.

In this embodiment, the first sub-working port v1 is used as an oil supply port of the double balance valve 100, and the second sub-working port v2 is used as an oil return port of the double balance valve 100. The first chamber 631 communicates with the first main working port c1, and the second chamber 632 communicates with the second main working port c 2. The oil liquid passes through the first main working oil port c1 and the first chamber 631 to push the piston 622 and the oil liquid of the second chamber 632 to pass through the second main working oil port c2 in sequence from the first sub working oil port v1, and finally returns through the second sub working oil port v 2.

In this embodiment, the first check valve 212 communicates the oil passage from the first sub-hydraulic port v1 to the first main hydraulic port c 1. The oil at the first sub-working port v1 is delivered to the first main working port c1 through the first check valve 212.

In this embodiment, the second check valve 222 communicates the second sub-hydraulic port v2 with the oil passage of the second main hydraulic port c 2. Since the second check valve 222 is in one-way communication, the oil path from the second main working port c2 to the second sub working port v2 through the second check valve 222 is blocked.

In this embodiment, the second pressure valve 221 has a second open position and a second closed position, and the second pressure valve 221 is switched from the second closed position to the second open position, so that the oil path from the oil port c2 to the oil port v2 can be communicated. Two ways of switching the second pressure valve 221 from the second closed position to the second open position are described in detail below.

The first mode is as follows: the second load port b2 has a second spool opening oil pressure, and when the oil pressure of the second load port b2 reaches the second spool opening oil pressure, the second pressure valve 221 is switched from a second closed position to a second open position. Specifically, the oil at the second main working oil port c2 is delivered to the second load oil port b2 through the second load oil passage 332, when the oil delivered at the second main working oil port c2 makes the oil pressure of the second load oil port b2 reach the oil pressure at which the second valve core opens, the second pressure valve 221 is switched from the second closed position to the second open position, the second main working oil port c2 is communicated with the oil passage of the second sub working oil port v2, and the oil at the second main working oil port c2 is delivered to the second sub working oil port v2 through the second pressure valve 221.

The second mode is as follows: the second control port a2 has a second pilot opening oil pressure, and when the oil pressure of the second control port a2 reaches the second pilot opening oil pressure, the second pressure valve 221 is switched from a second closed position to a second open position. Specifically, the oil at the first sub-working oil port v1 is delivered to the second end 412 of the connecting oil passage 410 through the second oil passage 320, and then the oil is delivered to the first end 411 along the connecting oil passage 410 and is delivered to the second control oil port a2 from the first end 411 along the first oil passage 310. When the oil pressure of the second control oil port a2 reaches the second pilot opening oil pressure by the oil delivered from the first sub working oil port v1, the second pressure valve 221 is switched from the second closed position to the second open position, the second main working oil port c2 is communicated with the oil passage of the second sub working oil port v2, and the oil delivered from the second main working oil port c2 is delivered to the second sub working oil port v2 through the second pressure valve 221.

The second spool opening oil pressure is the minimum value of the oil pressure at the second load port b2 when the second pressure valve 221 is switched from the second closed position to the second open position by the first manner described above.

When the second mode is separately adopted to switch the second pressure valve 221 from the second closed position to the second open position, the minimum value of the oil pressure at the first sub-hydraulic port v1 is the first pilot oil pressure. When the oil pressure of the second control port a2 is the second pilot opening oil pressure, the oil pressure at the first sub-hydraulic port v1 is the first pilot oil pressure.

The first pilot ratio of the double balanced valve 100 is a ratio of the second spool opening oil pressure to the first pilot oil pressure.

In this embodiment, a part of the oil at the first sub-working oil port v1 is sequentially delivered to the second control oil port a2 along the second oil passage 320, the first damper 510, the second end 412, the connecting oil passage 410, the first end 411, and the first oil passage 310. The rest part of the oil at the first sub-working oil port v1 is still continuously conveyed along the second oil passage 320 after being conveyed to the second end 412 through the first damping member 510, passes through the second damping member 520, and reaches the second sub-working oil port v2, and is returned through the second sub-working oil port v 2.

Since a part of the oil at the first sub-working port v1 is delivered to the second control port a2 through the connecting oil passage 410, the oil pressure at the first sub-working port v1 is higher than that at the second control port a 2. When the oil pressure of the second control port a2 is the second pilot-on oil pressure, the oil pressure at the first sub-working port v1 is higher than the second pilot-on oil pressure, that is, the first pilot oil pressure is greater than the second pilot-on oil pressure.

Therefore, the first oil passage 310 is connected with the first control oil port a1 and the second control oil port a2, the second oil passage 320 is connected with the first sub-working oil port v1 and the second sub-working oil port v2, the first end 411 of the connection oil passage 410 is located on the first oil passage 310, the second end 412 of the connection oil passage 410 is located on the second oil passage 320, and the first oil passage 310, the second oil passage 320 and the connection oil passage 410 are communicated, so that part of the oil at the first sub-working oil port v1 is conveyed to the second control oil port a2 through the connection oil passage 410, and the rest of the oil at the first sub-working oil port v1 is conveyed to the second sub-working oil port v2 along the second oil passage 320 to return oil, which is helpful for increasing the first pilot oil pressure, thereby reducing the first pilot ratio of the double balanced valve 100 to improve the smoothness of the load controlled by the hydraulic cylinder 600, reducing the risk of the hydraulic cylinder 600 rattling.

In this embodiment, the second damper 520 may be configured to split and reduce the oil pressure of the second end 412, that is, the oil pressure equal to the second control port a2, so that the oil pressure of the first sub-port v1 and the oil pressure of the second end 412 may be maintained at a certain ratio, that is, the ratio of the first pilot oil pressure to the second pilot opening oil pressure, and the ratio at this time satisfies:

first pilot oil pressure/second pilot opening oil pressure equal to α⁴/(α⁴+β⁴)；

Wherein α is a diameter of the first damping member 510; β is the diameter of the second damping member 520.

The damping coefficient of the second damping member 520 is greater than, equal to, or less than the damping coefficient of the first damping member 510.

When the damping coefficient of the second damping member 520 is equal to the damping coefficient of the first damping member 510, the amount of the oil delivered to the second control port a2 from the first sub-working port v1 is equal to the amount of the oil directly delivered to the second sub-working port v2 from the first sub-working port v1, and the first pilot oil pressure is twice the second pilot opening oil pressure.

When the damping coefficient of the second damping member 520 is smaller than that of the first damping member 510, the oil amount delivered to the second control oil port a2 by the first sub-working oil port v1 is smaller than the oil amount delivered to the second sub-working oil port v2 by the first sub-working oil port v1, and the first pilot oil pressure is greater than twice the second pilot opening oil pressure.

When the damping coefficient of the second damping member 520 is greater than that of the first damping member 510, the amount of the oil delivered to the second control oil port a2 from the first sub-working oil port v1 is greater than the amount of the oil delivered to the second sub-working oil port v2 from the first sub-working oil port v1, and the first pilot oil pressure is less than twice the second pilot opening oil pressure.

As can be seen from the above equation, by adjusting the damping coefficients of the second damping member 520 and the first damping member 510, the ratio of the first pilot oil pressure to the second pilot opening oil pressure can be adjusted, and the first pilot ratio of the double balanced valve 100 can be adjusted.

In other embodiments, the second sub-working oil port v2 may be used as an oil supply port of the double balance valve 100, and the first sub-working oil port v1 may be used as an oil return port of the double balance valve 100.

Referring to fig. 4, in another embodiment, the second sub-working oil port v2 serves as an oil supply port of the double balance valve 100, and the first sub-working oil port v1 serves as an oil return port of the double balance valve 100. The first chamber 631 communicates with the second main working port c2, and the second chamber 632 communicates with the first main working port c 1. The oil liquid passes through the second auxiliary working oil port v2 sequentially through the second main working oil port c2, the first chamber 631, the second chamber 632, the first main working oil port c1, and finally returns through the first auxiliary working oil port v 1.

The second check valve 222 communicates the second sub-working port v2 to the oil passage of the second main working port c 2.

The first check valve 212 connects the first sub-working port v1 to the oil passage of the first main working port c1, and the oil passage from the first main working port c1 to the first sub-working port v1 through the first check valve 212 is blocked because the first check valve 212 is in one-way communication.

The first pressure valve 211 has a first open position and a first closed position, and two methods for switching the first pressure valve 211 from the first closed position to the first open position are described in detail below.

The first method comprises the following steps: the first load port b1 has a first spool opening oil pressure, and when the oil pressure of the first load port b1 reaches the first spool opening oil pressure, the first pressure valve 211 is switched from a first closed position to a first open position.

The second method comprises the following steps: the first control port a1 has a first pilot opening oil pressure, and when the oil pressure of the first control port a1 reaches the first pilot opening oil pressure, the first pressure valve 211 is switched from a first closed position to a first open position. The oil in the second sub-working oil port v2 sequentially passes through the second oil passage 320, the second end 412, the connection oil passage 410, the first end 411 and the first oil passage 310 to the first control oil port a1, and when the oil delivered from the second sub-working oil port v2 makes the oil pressure of the first control oil port a1 reach the first pilot opening oil pressure, the first pressure valve 211 is switched from a first closed position to a first open position.

The first spool opening oil pressure is the minimum value of the oil pressure at the first load port b1 when the first pressure valve 211 is switched from the first closed position to the first open position by the above first method alone.

When the second method is separately adopted so that the first pressure valve 211 is switched from the first closed position to the first open position, the minimum value of the oil pressure at the second sub-working port v2 is the second pilot oil pressure. When the oil pressure of the first control port a1 is the first pilot opening oil pressure, the oil pressure of the second sub-working port v2 is the second pilot oil pressure.

The second pilot ratio of the double balanced valve 100 is a ratio of the first spool opening oil pressure to the second pilot oil pressure.

The first oil passage 310, the second oil passage 320 and the communication mode of the connecting oil passage 410 enable part of oil at the second sub-working oil port v2 to be sequentially conveyed to the first control oil port a1 along the second damping member 520, the second oil passage 320, the second end 412, the connecting oil passage 410, the first end 411 and the first oil passage 310, and the rest of oil at the second sub-working oil port v2 is conveyed to the first sub-working oil port v1 along the second oil passage 320 through the first damping member 510 and is returned by the first sub-working oil port v1, so that the second pilot oil pressure is increased, the second pilot ratio of the double balance valve 100 is reduced, the stability of the load controlled by the hydraulic cylinder 600 is improved, and the risk of shaking of the hydraulic cylinder 600 is reduced.

In this embodiment, the first damping member 510 can perform the pressure-splitting and pressure-reducing operation on the oil pressure of the second end 412, that is, the oil pressure equivalent to the first control port a1, so that the oil pressure of the second sub-working port v2 and the oil pressure of the second end 412 can be maintained at a certain ratio, that is, the ratio of the first pilot oil pressure to the second pilot opening oil pressure, and the ratio satisfies:

first pilot oil pressure/second pilot opening oil pressure equal to β⁴/(α⁴+β⁴)；

The damping coefficient of the second damping member 520 is greater than, equal to, or less than the damping coefficient of the first damping member 510. By adjusting the damping coefficients of the second damping member 520 and the first damping member 510, the ratio of the second pilot oil pressure to the first pilot opening oil pressure can be adjusted, and the second pilot ratio of the double balanced valve 100 can be adjusted.

Fig. 5 is a schematic diagram of the structure of the double balanced valve 100 shown in fig. 2.

Referring to fig. 5, in the present embodiment, the double balanced valve 100 includes: a main valve block 641, the main valve block 641 having a channel extending through both ends.

The first pressure valve 211 includes: the first valve core assembly 650 is located in the cavity, and the telescopic direction of the first valve core assembly 650 is along the axial direction of the cavity; the first sleeve 642 is located at one end of the main valve block 641, one end of the first sleeve 642 extends into the cavity, and the other end of the first sleeve 642 protrudes out of the cavity along the axial direction of the cavity; the first main spring assembly 660 is located in the first sleeve 642, the first main spring assembly 660 includes a first spring seat end 661 and a first spring 662, the first spring seat end 661 is located between the first valve core assembly 650 and the first spring 662, and under the elastic force of the first spring 662, the first spring seat end 661 abuts against the first valve core assembly 650.

In this embodiment, the first valve core assembly 650 includes a first valve core and a second spring 654 sleeved on the first valve core. The first valve core is provided with a first valve core head portion 651 and a first valve core tail portion 652 which are opposite to each other, the first valve core is further provided with a first middle portion 653 located between the first valve core head portion 651 and the first valve core tail portion 652, and the second spring 654 is sleeved on the first middle portion 653. The first one-way valve 212 is located between the second spring 654 and the first cartridge head 651. The first spool head 651 abuts the first spring seat end 661.

In this embodiment, the first spring seat end 661 and the first valve spool head 651 are a split structure. In other embodiments, the first spring seat end is integrally formed with the first spool head.

The second pressure valve 221 includes: the second valve core assembly 670 is positioned in the cavity, the telescopic direction of the second valve core assembly 670 is along the axial direction of the cavity, and one end of the second valve core assembly 670 is arranged opposite to one end of the first valve core assembly 650; a second sleeve 643, wherein the second sleeve 643 is located at the other end of the main valve block 641 opposite to the first sleeve 643, one end of the second sleeve 643 extends into the cavity, and the other end of the second sleeve 643 protrudes out of the cavity along the axial direction of the cavity; a second main spring assembly 680, the second main spring assembly 680 being located within the second sleeve 643, the second main spring assembly 680 including a second spring seat end 681 and a third spring 682, the second spring seat end 681 being located between the second spool assembly 670 and the third spring 682, the second spring seat end 681 abutting against the second spool assembly 670 under the elastic force of the third spring 682.

In this embodiment, the second spool assembly 670 includes a second spool and a third spring 674 sleeved on the second spool. The second valve core is provided with a second valve core head portion 671 and a second valve core tail portion 672 which are opposite to each other, the second valve core is further provided with a second middle portion 673 which is positioned between the second valve core head portion 671 and the second valve core tail portion 672, and the fourth spring 674 is sleeved on the second middle portion 673. The second one-way valve 222 is located between the second spring 674 and the second spool head 671. The second spool head 671 abuts the second spring seat end 681, and the second spool tail 672 opposes the first spool tail 652.

In this embodiment, the second spring seat end 681 and the second valve core head 671 are of a split structure. In other embodiments, the second spring seat end is integrally formed with the second spool head.

In this embodiment, the first main working port c1 is communicated with the cavity, one end of the first main working port c1 is aligned with the first middle portion 653 between the first spool tail 652 and the second spring 654, and the other end of the first main working port c1 penetrates through the side wall of the main valve block 641 in a direction perpendicular to the axial direction of the main valve block 641.

In this embodiment, the second main working port c2 is also communicated with the cavity, one end of the second main working port c2 is aligned with the second middle portion 673 between the second valve spool tail 672 and the fourth spring 674, and the other end of the second main working port c2 penetrates through the side wall of the main valve block 641 in a direction perpendicular to the axial direction of the main valve block 641.

In this embodiment, the first sub-working oil port v1 is located between the first valve core head 651 and the inner wall of the cavity, and the second sub-working oil port v2 is located between the second valve core head 671 and the inner wall of the cavity.

The present invention further provides a hydraulic control system 700, including the double balanced valve 100 as described above.

Referring to fig. 3, the hydraulic control system 700 further includes: the hydraulic cylinder 600 comprises a cylinder 610 and a piston rod 620, the piston rod 620 is suitable for reciprocating, the piston rod 620 is provided with a load end 621 and a piston 622 which are opposite, the load end 621 is exposed out of the hydraulic cylinder 600, the piston 622 divides an inner cavity of the cylinder 610 into a first chamber 631 and a second chamber 632, and the second chamber 632 is located between the piston 622 and the load end 621.

In this embodiment, the first sub-working port v1 is used as an oil supply port of the double balance valve 100, and the second sub-working port v2 is used as an oil return port of the double balance valve 100. The first chamber 631 communicates with the first main working port c1, and the second chamber 632 communicates with the second main working port c 2. The oil liquid passes through the first auxiliary working oil port v1 sequentially through the first main working oil port c1, the first chamber 631, the second chamber 632, the second main working oil port c2, and finally returns through the second auxiliary working oil port v 2.

Referring to fig. 5 in combination, in this embodiment, when the first chamber 631 communicates with the first main working port c1, and the second chamber 632 communicates with the second main working port c2, the double balanced valve 100 further includes: a second limiting shim fixedly disposed on the second spring seat end 681 and located between the second spring seat end 681 and the third spring 682, the second limiting shim adapted to limit a maximum distance that the second valve core tail 672 moves along the axial direction of the second sleeve 643 toward the outside of the cavity.

The second limiting gasket is fixedly arranged on the second spring seat end 681, and when the second limiting gasket moves to a second limiting step on the inner wall of the second sleeve 643, the second spring seat end 681 reaches the maximum distance moving towards the outside of the cavity along the axial direction of the second sleeve 643, and further the second valve spool assembly 670 also reaches the maximum distance moving towards the outside of the cavity along the axial direction of the sleeve 642, and at this time, the opening size of the second secondary working oil port v2 reaches the maximum value.

Compare in the piston 622 is located one side of first chamber 631, the piston 622 is located the effective oil pressure area of one side of second chamber 632 is little, works as the second chamber 632 with when second main hydraulic fluid port c2 is linked together, the spacing gasket of second sets firmly in on the second spring seat end 681, the spacing gasket of second helps reducing the maximum value of the opening size of the vice hydraulic fluid port v2 of second for the process the nominal flow of the vice hydraulic fluid port v2 oil return reduces, further reduces the too fast risk that leads to the pneumatic cylinder to take place the shake of vice hydraulic fluid port v2 step-down speed of second.

In this embodiment, the second limiting gasket and the second spring seat end 681 are fixed in a threaded connection, a clamping connection, or a welding connection.

In the embodiment shown in fig. 4, when the first chamber 631 communicates with the second main working port c2 and the second chamber 632 communicates with the first main working port c1, referring to fig. 6, the double balanced valve 100 further includes: a first limiting gasket 691, the first limiting gasket 691 is fixedly arranged on the first spring seat end 661, the first limiting gasket 691 is located between the first spring seat end 661 and the first spring 662, and the first limiting gasket 691 is suitable for limiting the maximum distance of the first spool tail 652 moving towards the outside of the cavity along the axial direction of the first sleeve 642.

The first limiting shim 691 is fixedly arranged on the first spring seat end 661, when the first limiting shim 691 moves to the first limiting step 690 on the inner wall of the first sleeve 642, the first spring seat end 661 reaches the maximum distance of moving towards the outside of the cavity along the axial direction of the first sleeve 642, and further the first valve core assembly 650 also reaches the maximum distance of moving towards the outside of the cavity along the axial direction of the first sleeve 642, at this time, the opening size of the first secondary working oil port v1 (refer to fig. 5) reaches the maximum value.

Compared with the piston 622 located at one side of the first chamber 631, the effective oil pressure area of the piston 622 located at one side of the second chamber 632 is small, when the second chamber 632 is communicated with the first main working oil port c1, the first limit gasket 691 is fixedly arranged on the first spring seat end 661, and the first limit gasket 691 is beneficial to reducing the maximum value of the opening size of the first sub working oil port v1, so that the nominal flow of oil returning through the first sub working oil port v1 is reduced, and the risk that the hydraulic cylinder shakes due to the fact that the pressure reduction speed of the first sub working oil port v1 is too high is further reduced.

Wherein, the first limit gasket 691 and the first spring seat end 661 are fixed by screw joint, clamping or welding.

The hydraulic control system 700 further includes: the oil duct still includes: the first oil return passage is connected with the first auxiliary working oil port v1 and the oil tank, and the second oil return passage is connected with the second auxiliary working oil port v2 and the oil tank.

Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one of ordinary skill in the pertinent art without departing from the scope or spirit of the present invention, and the scope of the present invention is defined by the appended claims.

Claims

1. A dual balanced valve, comprising:

the first balance valve comprises a first pressure valve and a first check valve, the first pressure valve is provided with a first main working oil port, a first auxiliary working oil port and a first control oil port, one end of the first check valve is connected with the first main working oil port, and the other end of the first check valve is connected with the first auxiliary working oil port;

the second balance valve comprises a second pressure valve and a second check valve, the second pressure valve is provided with a second main working oil port, a second auxiliary working oil port and a second control oil port, one end of the second check valve is connected with the second main working oil port, and the other end of the second check valve is connected with the second auxiliary working oil port;

the oil duct comprises a first oil duct, a second oil duct and a connecting oil duct, the first oil duct is connected with the first control oil port and the second control oil port, the second oil duct is connected with the first auxiliary working oil port and the second auxiliary working oil port, the connecting oil duct is provided with a first end part and a second end part, the first end part is positioned on the first oil duct, the second end part is positioned on the second oil duct, and the first oil duct, the second oil duct and the connecting oil duct are communicated;

the first damping piece is arranged on the second oil duct and is positioned between the second end part and the first auxiliary working oil port;

and the second damping piece is arranged on the second oil duct, and is positioned between the second end part and the second auxiliary working oil port.

2. The double balanced valve of claim 1, wherein the damping coefficient of the second damping member is greater than, equal to, or less than the damping coefficient of the first damping member.

3. The double balance valve of claim 1 wherein the first check valve communicates the first secondary working port to the oil path of the first primary working port and the second check valve communicates the second secondary working port to the oil path of the second primary working port.

4. The dual balance valve of claim 1 wherein said first pressure valve further has a first load port and said second pressure valve further has a second load port; the oil passage further includes: the first load oil duct is connected with the first load oil port and the first main working oil port, and the second load oil duct is connected with the second load oil port and the second main working oil port.

5. The double balanced valve of claim 4, wherein the first pressure valve has a first open position and a first closed position, the first load port has a first spool opening oil pressure, and the first pressure valve switches from the first closed position to the first open position when the oil pressure of the first load port reaches the first spool opening oil pressure; the second pressure valve is provided with a second opening position and a second closing position, the second load oil port is provided with a second valve core opening oil pressure, and when the oil pressure of the second load oil port reaches the second valve core opening oil pressure, the second pressure valve is switched to the second opening position from the second closing position.

6. The double balance valve of claim 5 wherein said first control port has a first pilot opening oil pressure, said first pressure valve switching from a first closed position to a first open position when the oil pressure of said first control port reaches said first pilot opening oil pressure; the second pressure valve is provided with a second opening position and a second closing position, the second control oil port is provided with a second pilot opening oil pressure, and when the oil pressure of the second control oil port reaches the second pilot opening oil pressure, the second pressure valve is switched to the second opening position from the second closing position.

7. A double balanced valve as defined in claim 1 in which said first pressure valve also has a first spring chamber drain port and said second pressure valve also has a second spring chamber drain port; the oil passage further includes: the first spring cavity oil drainage channel is connected with the first spring cavity oil drainage port and the first auxiliary working oil port, and the second spring cavity oil drainage channel is connected with the second spring cavity oil drainage port and the second auxiliary working oil port.

8. A hydraulic control system comprising a double balanced valve as claimed in any one of claims 1 to 7.

9. The hydraulic control system of claim 8, further comprising: the hydraulic cylinder comprises a cylinder barrel and a piston rod, the piston rod is suitable for reciprocating, the piston rod is provided with a load end and a piston which are opposite, the load end is exposed out of the hydraulic cylinder, the piston divides an inner cavity of the cylinder barrel into a first cavity and a second cavity, and the second cavity is located between the piston and the load end.

10. The hydraulic control system of claim 9, further comprising: the oil duct still includes: the first oil return duct is connected with the first auxiliary working oil port and the oil tank, and the second oil return duct is connected with the second auxiliary working oil port and the oil tank.

11. The hydraulic control system of claim 9, wherein the double balancing valve comprises: the main valve block is provided with a cavity which penetrates through two ends;

the first pressure valve includes:

the first valve core assembly is positioned in the cavity, and the telescopic direction of the first valve core assembly is along the axial direction of the cavity;

the first sleeve is positioned at one end of the main valve block, one end of the first sleeve extends into the cavity, and the other end of the first sleeve protrudes out of the cavity along the axis direction of the cavity;

the first main spring assembly is located in the first sleeve and comprises a first spring seat end and a first spring, the first spring seat end is located between the first valve core assembly and the first spring, and the first spring seat end is abutted to the first valve core assembly under the action of elastic force of the first spring.

12. The hydraulic control system of claim 11, wherein the second pressure valve comprises: the second valve core assembly is positioned in the cavity, the telescopic direction of the second valve core assembly is along the axial direction of the cavity, and one end of the second valve core assembly is opposite to one end of the first valve core assembly;

the second sleeve is positioned at the other end of the main valve block opposite to the first sleeve, one end of the second sleeve extends into the cavity, and the other end of the second sleeve protrudes out of the cavity along the axis direction of the cavity;

the second main spring assembly is located in the second sleeve and comprises a second spring seat end and a third spring, the second spring seat end is located between the second valve spool assembly and the third spring, and under the action of elastic force of the third spring, the second spring seat end is abutted to the second valve spool assembly.

13. The hydraulic control system of claim 12, wherein when the first chamber is in communication with the second main working port and the second chamber is in communication with the first main working port, the double balancing valve further comprises: the first limiting gasket is fixedly arranged on the first spring seat end, and is positioned between the first spring seat end and the first spring.

14. The hydraulic control system of claim 12, wherein when the first chamber is in communication with the first main working port and the second chamber is in communication with the second main working port, the double balancing valve further comprises: and the second limiting gasket is fixedly arranged on the second spring seat end and is positioned between the second spring seat end and the third spring.