CN116220142A

CN116220142A - Loader hydraulic system and loader

Info

Publication number: CN116220142A
Application number: CN202310259957.7A
Authority: CN
Inventors: 马鹏鹏; 乔战战; 张安民; 范小童; 孙志远; 李建洋
Original assignee: Science and Technology Branch of XCMG
Current assignee: Science and Technology Branch of XCMG
Priority date: 2023-03-17
Filing date: 2023-03-17
Publication date: 2023-06-06

Abstract

The invention discloses a loader hydraulic system and a loader in the technical field of loaders, wherein a variable pump inputs hydraulic oil into a steering hydraulic cylinder through a priority valve and a steering gear to control the steering of the loader; the variable pump inputs hydraulic oil into the first executive component and the second executive component through the priority valve and the energy-saving multi-way valve, and is used for controlling the first executive component and the second executive component to complete single action or compound action; the LS2 port of the energy-saving multi-way valve is connected with the LS3 port of the priority valve and is used for controlling the steering hydraulic cylinder, the first executing element and the second executing element to complete single action or compound action; the combined action of the steering, the movable arm and the tipping bucket of the loader can be realized, the variable effect of the variable pump can be fully exerted, and the energy conservation can be realized.

Description

Loader hydraulic system and loader

Technical Field

The invention belongs to the technical field of loaders, and particularly relates to a loader hydraulic system and a loader.

Background

As a scraper, a loader is used as a construction machine for which efficiency is desired. The shoveling and loading of the loader are realized through a hydraulic system of the loader, which is realized by combining and combining the steering, the movable arm and the tipping bucket, and the hydraulic system of the loader is generally mainly composed of a working hydraulic system and a steering hydraulic system.

The quantitative hydraulic system can realize independent control of the working hydraulic system and the steering hydraulic system, but the hydraulic system has low efficiency, can not realize combined and combined actions of steering, tipping bucket and movable arm, and has larger bypass throttling loss. The fixed-variable hydraulic system realizes the combination of steering and tipping bucket (movable arm), but due to the adoption of the open-center multi-way valve, the combination of the three components or the combination of the movable arm and the tipping bucket cannot be realized, and meanwhile, when a working device acts, the variable pump is in a quantitative state, is output in full displacement, cannot play the regulating function of the variable pump according to the system requirement, and has poorer energy-saving effect.

Disclosure of Invention

In order to solve the defects in the prior art, the invention provides a hydraulic system of a loader and the loader, which can realize the combined and combined actions of steering, movable arms and tipping buckets of the loader, fully exert the variable effect of a variable pump and realize energy conservation.

In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:

in a first aspect, there is provided a loader hydraulic system comprising: the variable pump, the priority valve, the steering gear and the energy-saving multi-way valve; the variable pump inputs hydraulic oil into a steering hydraulic cylinder through a priority valve and a steering gear and is used for controlling the steering of the loader; the variable pump inputs hydraulic oil into the first executive component and the second executive component through the priority valve and the energy-saving multi-way valve, and is used for controlling the first executive component and the second executive component to complete single action or compound action; and an LS2 port of the energy-saving multi-way valve is connected with an LS3 port of the priority valve and is used for controlling the steering hydraulic cylinder, the first executing element and the second executing element to complete single action or compound action.

Further, the energy-saving multiway valve comprises: the first main valve core is used for controlling the communication or disconnection of the input oil ports P1 and P2 and the output oil ports A1 and B1; the second main valve core is used for controlling the communication or disconnection of the input oil ports P1 and P2 and the output oil ports A2 and B2; when the first main valve core and the second main valve core do not act, the input oil ports P1 and P2 are separated from the output oil ports A1 and B1 through the first main valve core (51); the input oil ports P1 and P2 are separated from the output oil ports A2 and B2 through a second main valve core; when the first main valve core acts, hydraulic oil input by the input oil ports P1 and P2 enters a first bypass through a sixth one-way valve; the first bypass is connected with the output oil ports A1 and B1 through a first main valve core, and is fed back to the LS oil port through a fifth one-way valve; when the second main valve core acts, hydraulic oil input by the input oil ports P1 and P2 enters a second bypass through a third one-way valve; the second bypass is connected with the output oil ports A2 and B2 through the second main valve core, and is fed back to the LS oil port through the fourth one-way valve.

Further, the energy-saving multi-way valve further comprises control oil ports a1, a2, b1 and b2, wherein the control oil port a1 is communicated with the right cavity end of the first main valve core and is used for controlling the first main valve core to move leftwards to be at a right position; the control oil port b1 is communicated with the left cavity end of the first main valve core and is used for controlling the first main valve core to move rightwards to be at a left position; the control oil port a2 is communicated with the right cavity end of the second main valve core and is used for controlling the second main valve core to move leftwards to be at a right position; the control oil port b2 is communicated with the left cavity end of the second main valve core and is used for controlling the second main valve core to move rightwards to be in a left one position or a left two position; the control oil port a1 is communicated with an oil inlet of the reversing valve core through a first damping, meanwhile, the oil inlet of the reversing valve core is communicated with a right cavity end of the first main valve core, and an oil outlet of the reversing valve core is communicated with the T port through a second damping; the control oil port a2 is communicated with the right control end of the reversing valve core, and the left side of the reversing valve core is controlled by a spring and is communicated with the T port.

Further, the output oil port B1 is communicated with the output oil port B2 through a first one-way valve and a second one-way valve and is used for supplementing oil to rod cavities of the first executing element and the second executing element.

Further, the energy-saving multi-way valve further comprises a pilot oil source valve, an oil inlet of the pilot oil source valve is communicated with an Mp port of the energy-saving multi-way valve, an oil outlet of the pilot oil source valve is sequentially connected with a two-way ball valve and a pilot valve, and the pilot valve is used for controlling the first main valve core and the second main valve core through control oil ports a1, a2, b1 and b 2.

Further, the composite action includes: rotating the two-way ball valve to switch the two-way ball valve from a first working position to a second working position, and controlling control oil ports a1 and a2 of the energy-saving multipath valve through the pilot valve to enable the first main valve core and the second main valve core to move leftwards; realizing the displacement ratio of the first main valve core and the second main valve core according to the pressure of the control oil port a 2; when the pressure of the control oil port a2 is regulated to be larger than the pressure set by the spring, the reversing valve core is switched from a first working position to a second working position, and the pressure of the control oil port a1 passes through the first damping, the reversing valve core and the second damping to reduce pressure, so that the pressure of the right cavity end of the first main valve core is reduced, and the position change of the first main valve core is controlled; and regulating and controlling the pressure reaching the right control end of the first main valve core according to the pressure of the control oil port a2 to form displacement matching of the first main valve core and the second main valve core.

Further, the composite action further includes: the first main valve core and the second main valve core are both reversed to the right, and an oil inlet of the first main valve core is communicated with an output oil port A1 through a choke from a sixth one-way valve to the first main valve core; the fifth one-way valve is communicated with the LS2 port so as to feed back a load pressure signal of the first execution element to the LS2 port; an oil inlet of the second main valve core passes through a third one-way valve to a throttling port of the second main valve core to be discharged, and is communicated with an output oil port A2; the load pressure signal of the second execution element is fed back to the LS2 port through the fourth one-way valve, the higher pressure is transmitted to the LS2 port after the two load feedback pressures are compared, and the lower pressure is cut off due to the one-way valve; the variable pump can provide flow according to the opening requirements of the first main valve core and the second main valve core.

Further, the composite action further includes: the first main valve core moves left to a certain distance, at the moment, the output oil port A1 is communicated with the first bypass through the first main valve core, and the output oil port B1 is communicated with the T port through the first main valve core; the input oil port P1 enters a first bypass through a first main valve core and a sixth one-way valve; the first bypass is communicated with the LS2 port through a fifth one-way valve; the second main valve core moves leftwards to a certain distance, at the moment, an output oil port A2 is communicated with the second bypass through the second main valve core, and an output oil port B2 is communicated with the T port through the second main valve core; the input oil port P1 enters the second bypass through the second main valve core and the third one-way valve, the second bypass is communicated with the LS2 port through the fourth one-way valve, and compared with the second bypass and the fourth one-way valve, the second bypass is communicated with the LS2 port, and the second bypass is reversely cut off due to the one-way valve.

In a second aspect, a loader is provided, which is configured with the loader hydraulic system of the first aspect.

Compared with the prior art, the invention has the beneficial effects that:

(1) The variable pump inputs hydraulic oil into the steering hydraulic cylinder through the priority valve and the steering gear, and is used for controlling the steering of the loader; the variable pump inputs hydraulic oil into the first executive component and the second executive component through the priority valve and the energy-saving multi-way valve, and is used for controlling the first executive component and the second executive component to complete single action or compound action; the LS2 port of the energy-saving multi-way valve is connected with the LS3 port of the priority valve and is used for controlling the steering hydraulic cylinder, the first executing element and the second executing element to complete single action or compound action; the combined action of the steering, the movable arm and the tipping bucket of the loader can be realized, the variable effect of the variable pump can be fully exerted, and the energy conservation can be realized;

(2) The invention adopts an inlet one-way valve structure to replace the original pressure compensator structure, and utilizes the pilot compensation valve core to realize different positions of valve core displacement, thereby realizing compound action;

(3) The variable pump disclosed by the invention is used for participating in variable adjustment in the whole process, so that the combined and combined actions of steering, movable arms and tipping buckets of the loader are realized, the variable effect of the variable pump is fully exerted, and the energy conservation is realized.

Drawings

FIG. 1 is a hydraulic schematic diagram of an energy-efficient multiway valve in an embodiment of the invention;

FIG. 2 is a schematic view of a first view angle structure of an energy-saving multi-way valve according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of the structure of a central section of an energy-saving multi-way valve according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of the structure of the energy-saving multi-way valve according to the embodiment of the invention, which is a bottom view of FIG. 2;

FIG. 5 is a schematic cross-sectional view of a first main spool of an energy-efficient multi-way valve according to an embodiment of the present invention;

FIG. 6 is a schematic cross-sectional view of a second main spool of an energy efficient multi-way valve according to an embodiment of the present invention;

FIG. 7 is a schematic cross-sectional view of a fourth check valve and a sixth check valve of the energy-saving multi-way valve according to the embodiment of the present invention;

FIG. 8 is a schematic cross-sectional view of a reversing valve core of an energy-efficient multiway valve in an embodiment of the invention;

FIG. 9 is a schematic diagram of a hydraulic system using an energy-saving multiway valve as an embodiment of the invention;

in the figure: 1. a variable displacement pump; 2. a diverter; 3. a steering hydraulic cylinder; 4. a priority valve; 5. a pilot oil source valve; 6. a first actuator; 7. a second actuator; 8. an energy-saving multi-way valve; 9. an oil return filter; 10. a heat sink; 11. a hydraulic oil tank; 12. a two-way ball valve; 13. a pilot valve; 51. a first main spool; 52. a second main spool; 53. a main safety valve; 54. LS overflow valve; 55. a constant flow valve; 56. a first overload valve; 57. a first one-way valve; 58. a second overload valve; 59. a second one-way valve; 60. a third one-way valve; 61. a fourth one-way valve; 62. a fifth check valve; 63. a sixth one-way valve; 64. a reversing valve core; 65. a spring; 66. a first damping; 67. a second damping; 68. and third damping.

Detailed Description

The invention is further described below with reference to the accompanying drawings. The following examples are only for more clearly illustrating the technical aspects of the present invention, and are not intended to limit the scope of the present invention.

Embodiment one:

as shown in fig. 1 to 9, a loader hydraulic system includes: a variable pump 1, a priority valve 4, a steering gear 2 and an energy-saving multi-way valve 8; the variable pump 1 inputs hydraulic oil into the steering hydraulic cylinder 3 through the priority valve 4 and the steering gear 2 for controlling the steering of the loader; the variable pump 1 inputs hydraulic oil into the first executive component 6 and the second executive component 7 through the priority valve 4 and the energy-saving multi-way valve 8, and is used for controlling the first executive component 6 and the second executive component 7 to complete single action or compound action; the LS2 port of the energy-saving multi-way valve 8 is connected with the LS3 port of the priority valve 4 and is used for controlling the steering hydraulic cylinder 3, the first executing element 6 and the second executing element 7 to complete single action or compound action.

As shown in fig. 1, the energy-saving multi-way valve 8 is composed of a P1 port, a P2 port, an MP port, an LS2 port, a T port, an A1 port, an A2 port, a B1 port, a B2 port, and A2', B2'.

The energy-saving multi-way valve 8 comprises a first main valve core 51 with three positions and a closed center, a second main valve core 52 with four positions and a closed center, a main safety valve 53, an LS overflow valve 54, a constant flow valve 55, a first overload valve 56, a first one-way valve 57, a second overload valve 58, a second one-way valve 59, a third one-way valve 60, a fourth one-way valve 61, a fifth one-way valve 62, a sixth one-way valve 63, a reversing valve core 64, a spring 65, a first damping 66, a second damping 67 and a third damping 68.

The three functional positions of the first main valve element 51 are left, middle and right, respectively, and the oil inlet passage is blocked at the middle position, and the pressure oil for driving the first actuator 6 cannot be output through the first main valve element 51. The first actuator 6, i.e. the skip cylinder of the loader. The small cavity B1 of the first executing element 6 is communicated with the oil outlet of the first one-way valve 57, the oil inlet of the first one-way valve 57 is communicated with the T-port, and the small cavity B1 is used for supplementing oil to the small cavity of the first executing element 6 and preventing suction. The small cavity B1 port of the first executive component 6 is communicated with the oil inlet of the first overload valve 56, the oil outlet of the first overload valve 56 is communicated with the T port, the overload protection is carried out on the small cavity B1 port of the first executive component 6, the large cavity A1 port of the first executive component 6 is communicated with the oil inlet of the second overload valve 58, the oil outlet of the second overload valve 58 is communicated with the T port, and the overload protection is carried out on the large cavity A1 port of the first executive component 6.

The four functional positions of the second main spool 52 are left, middle, and right, respectively, and the oil intake passage is blocked at the middle position, and the pressure oil for driving the second actuator 7 cannot be output through the second main spool 52. The left two positions communicate the oil outlet port A2 and the oil outlet port B2 of the second main valve core 52 with the oil return port T at the same time. The second actuator 7 is the boom cylinder of the loader. The port B2 of the small cavity of the second executing element 7 is communicated with the oil outlet of the second one-way valve 59, and the oil inlet of the second one-way valve 59 is communicated with the port T for supplementing oil to the small cavity of the second executing element 7, so that suction is prevented.

The port P1 is connected with the EF port of the second working oil port of the priority valve 4, the port LS2 is connected with the port LS3 of the priority valve 4, the port LS1 of the priority valve 4 is connected with the port LS2 of the steering gear 2, the port LS2 of the priority valve 4 is connected with the port X of the variable pump 1, and the pressure of the port LS2 of the priority valve 4 is fed back to the variable pump 1 after comparing the steering load signal with the working load signal, so that the variable pump 1 can provide pressure oil according to the load demand.

The control oil port a1 is communicated with 3 ports of the pilot valve 13, and is used for controlling the first main valve core 51 to move leftwards to be in a right position. The control oil port b1 is communicated with the 2 ports of the pilot valve 13, and is used for controlling the second main valve core 52 to move rightward to be in a left position.

The control oil port a2 is communicated with the 4 ports of the pilot valve 13, and is used for controlling the second main valve core 52 to move leftwards to be in a right position. The control oil port b2 is communicated with the 1 port of the pilot valve 13, and is used for controlling the second main valve core 52 to move rightwards to be in a left one position or a left two position.

The hydraulic oil in the port T flows into a hydraulic oil tank 11 through a radiator 10 and an oil return filter 9 for oil return of the hydraulic system.

The port A1 and the port B1 are connected with the large and small cavities of the skip bucket cylinder of the first executing element 6 and are used for outputting flow to the skip bucket cylinder of the first executing element 6.

The port A2 and the port B2 are connected with the large cavity and the small cavity of the movable arm cylinder of the second execution element 7 and are used for outputting flow to the movable arm cylinder of the second execution element 7.

The Mp port is communicated with the P1 port through an oil duct, the Mp port is connected with the P port of the pilot oil source valve 5, the A port of the pilot oil source valve 5 is communicated with the oil inlet of the two-way ball valve 12, and the oil outlet of the two-way ball valve 12 is communicated with the P port of the oil inlet of the pilot valve 13. The two-way ball valve 12 is used for cutting off the oil passage of the pilot valve 13 to prevent misoperation.

When the first main valve core 51 is in the middle position, the oil inlet of the first main valve core 51 is in a cut-off state, when the first main valve core 51 is changed in direction, the oil inlet of the first main valve core 51 passes through a left or right oil path of the first main valve core 51, passes through a sixth one-way valve 63, enters a throttle of the first main valve core 51, is output from an oil outlet A1 or a B1 port of the throttle, supplies oil to the first executing element 6, and the oil return of the first executing element 6 passes through the other oil outlet and returns oil through the first main valve core 51.

When the second main valve core 52 is in the middle position, the oil inlet of the second main valve core 52 is in a cut-off state, when the second main valve core 52 is changed in direction, the oil inlet of the second main valve core 52 passes through a right or left one-position oil path of the second main valve core 52, passes through the third one-way valve 60, flows out to a throttle of the second main valve core 52, is output from an oil outlet A2 or a B2 of the throttle, supplies oil to the second executing element 7, and the oil return of the second executing element 7 passes through the other oil outlet and returns oil through the second main valve core 52. When the second main valve core 52 is reversed to the left position, the oil inlet of the second main valve core 52 returns to the second main valve core 52 again through the third one-way valve 60 to be communicated with the oil return port T, the port A2 and the port B2 are simultaneously communicated with the oil return port T through the left position of the second main valve core 52, and the second executing element 7 is in a floating state.

The feedback port of the first main valve core 51 is communicated with the feedback port of the second main valve core 52 through a fifth one-way valve 62 through a fourth one-way valve 61 to form an LS port or an LS2 port of the energy-saving multi-way valve 8, the LS port is communicated with the oil inlet of the constant-current valve 55 at the same time, and the oil outlet of the constant-current valve 55 is communicated with the T port.

The LS2 port is communicated with the LS port through a third damper 68, the LS port is communicated with an oil inlet of the LS overflow valve 54, and an oil outlet of the LS overflow valve 54 is communicated with the T port.

The P1 port and the P2 port are connected with an oil inlet of the main safety valve 53, and an oil outlet of the main safety valve 53 is communicated with the T port.

The control oil port a1 is communicated with 3 ports of the pilot valve 13, is communicated with the right cavity end of the first main valve core 51, and is used for controlling the first main valve core 51 to move leftwards to be in a right position. The control oil port b1 is communicated with the 2 ports of the pilot valve 13, is communicated with the left cavity end of the first main valve core 51, and is used for controlling the second main valve core 52 to move rightward to be in a left position.

The control oil port a2 is communicated with the 4 ports of the pilot valve 13, is communicated with the right cavity end of the second main valve core 52, and is used for controlling the second main valve core 52 to move leftwards to be in the right position. The control oil port b2 is communicated with the 1 port of the pilot valve 13, is communicated with the left cavity end of the second main valve core 52, and is used for controlling the second main valve core 52 to move rightwards to be in a left one position or a left two position.

The port a1 of the control oil port is communicated with an oil inlet of the reversing valve 64 through a first damping 66, meanwhile, the oil inlet of the reversing valve 64 is communicated with a right cavity end of the first main valve core 51, and an oil outlet of the reversing valve 64 is communicated with a T port of the energy-saving multi-way valve 8 through a second damping 67. The port a2 of the control oil port is communicated with the control end on the right side of the reversing valve 64, and the left side of the reversing valve is controlled by a spring to control the reversing valve 64 to move and is communicated with the port T.

When the control oil ports a1 and a2 simultaneously have pressure oil, and the pressure of the port a2 is larger than the pressure set by the spring 65, the reversing valve 64 is switched from the first working position to the second working position, and at this time, the pressure of the port a1 passes through the first damper 66, the reversing valve 64 and the second damper 67, so that the pressure of the right cavity end of the first main valve core 51 is reduced, and the position change of the first main valve core 51 is controlled. By adjusting the pressure of the port a2 and adjusting the pressure of the right control end of the first main valve core 51, the displacement matching of the first main valve core 51 and the second main valve core 52 is formed, and the compound action is realized.

The working principle of the hydraulic system in this embodiment is as follows:

1. no operation acts: first main spool 51 and second main spool 52 are both in neutral position. The LS2 feedback port is disconnected with the oil inlet and the oil outlet through the main valve core, the LS2 port oil way is communicated with the T port through the constant flow valve 55, and no load feedback pressure exists, so that the variable pump 1 operates at minimum displacement, and the standby pressure of the variable pump port is maintained.

The method comprises the following steps: the P1 oil duct and the P2 oil duct of the energy-saving multi-way valve 8 are isolated from the T port through the first main valve core 51 and the second main valve core 52, so that the core closing principle is realized. The oil passage A1B1' (first bypass, in fig. 1, after the sixth check valve 63, to between the first main spool 51 and the second main spool 52) is blocked from the oil ports A1, B1 by the first main spool 51; the A2B2' oil passage (the second bypass, in FIG. 1, between the third check valve 60 and the second main spool 52) is blocked from the oil ports A2, B2 by the second main spool 52; the LS2 oil port is separated from the oil ports A1, B1, A2 and B2, so that no load feedback pressure is fed back to the variable pump 1.

2. Single action: taking the operation arm linkage as an example, when the two-way ball valve 12 is manually rotated, the two-way ball valve 12 is switched from a first working position to a second working position, at the moment, the pilot valve 13 is moved, so that 2 ports in the pilot valve 13 have output pressure to the B1 end of the energy-saving multi-way valve 8, the second main valve core 52 is reversed to the left position, and an oil inlet of the second main valve core 52 is communicated with the port B2 through a throttling port from the third one-way valve 60 to the second main valve core 52; the load pressure signal of the second actuator 7 is fed back to the LS2 port through the fourth one-way valve 61 and fed back to the X port of the variable pump 1 through the LS3 port of the priority valve 4 to the LS2 port of the priority valve 4, so that the variable pump 1 can provide flow according to the opening requirement of the second main valve core 52. When the load pressure of the second actuator 7 is higher than the set pressure of the LS relief valve 54, the LS relief valve 54 is opened, and the LS2 oil flows back to the hydraulic oil tank 11 through the constant flow valve 55 and the LS relief valve 54 and through the T port of the energy-saving multi-way valve 8.

The method comprises the following steps: second main spool 52 moves to the right a distance, at which time oil passage B2 communicates with oil passage A2B2' through second main spool 52, and oil passage A2 communicates with oil passage T through second main spool 52. The P1 oil passage passes through the second main spool 52, through the third check valve 60, and into the oil passage A2B2'. The oil passage A2B2' communicates with the LS2 oil passage through the fourth check valve 61, thereby feeding back the load signal to the X port of the variable displacement pump 1.

The pilot valve 13 is pushed continuously, so that the output pressure of the 2 ports in the pilot valve 13 is increased continuously, when the maximum output pressure of the 2 ports in the pilot valve 13 is increased, the second main valve core 52 is switched to the left two positions, the port A2 and the port B2 of the second main valve core 62 are communicated with the oil return T through the left two positions of the second main valve core 52, and the second executing element 7 is in a floating state. At this time, the LS port has no pressure feedback, and the variable pump 1 is in the minimum displacement and standby pressure state.

The method comprises the following steps: the second main valve core 52 continues to move rightwards to the set value, at this time, the oil duct B2 is communicated with the oil duct A2B2' through the second main valve core 52, the oil duct B2 is communicated with the oil duct T through the second main valve core 52, and the oil duct A2 is communicated with the oil duct T through the second main valve core 52, so that oil ports A2, B2 and T are communicated, and a floating state is realized.

3. And (5) compound action. When the two-way ball valve 12 is manually rotated, the two-way ball valve 12 is switched from the first working position to the second working position, the pilot valve 13 is moved at this time, and meanwhile, 3 ports and 4 ports in the pilot valve 13 have output pressures to the a1 end and the a2 end of the energy-saving multi-way valve 8, so that the first main valve core 51 and the second main valve core 52 move leftwards. According to the pressure of the port a2, the displacement ratio of the first main valve core 51 and the second main valve core 52 is realized. When the pressure of the port a2 is adjusted to be larger than the pressure set by the spring 65, the reversing valve 64 is switched from the first working position to the second working position, and at the moment, the pressure of the port a1 is reduced through the first damping 66, the reversing valve 64 and the second damping 67, so that the pressure of the right cavity end of the first main valve core 51 is reduced, and the position change of the first main valve core 51 is controlled. According to the pressure of the port a2, the pressure reaching the right control end of the first main valve core 51 is regulated and controlled, so that the displacement matching of the first main valve core 51 and the second main valve core 52 is formed.

Because both the first main valve core 51 and the second main valve core 52 are reversed to the right, the oil inlet of the first main valve core 51 is communicated with the port A1 through the choke outlet of the sixth check valve 63 to the first main valve core 51; communicate with port LS2 via fifth check valve 62 to feed back the load pressure signal of first actuator 6 to port LS 2; the oil inlet of the second main valve core 52 passes through the third one-way valve 60 to the choke outlet of the second main valve core 52 and is communicated with the port A2; the load pressure signal of the second actuator 7 is fed back to the LS2 port through the fourth check valve 61, the higher pressure is transmitted to the LS2 port after the two load feedback pressures are compared, and the lower pressure is cut off due to the check valve. For example, the load pressure of the first actuator 6 is high, the load feedback pressure is transmitted to the LS2 port through the fifth check valve 62, and the load pressure of the second actuator 7 is blocked by the fourth check valve 61. The pressure of the LS2 port is fed back to the X port of the variable pump 1 through the LS3 port of the priority valve 4 to the LS2 port of the priority valve 4, so that the variable pump 1 can provide flow according to the opening requirements of the first main valve core 51 and the second main valve core 52.

The method comprises the following steps: because the pressure at the a2 end acts on the left end of the reversing valve core 64, so that the reversing valve core 64 moves rightwards, the pressure at the a1 end is communicated with a spring 65 cavity through a first damping 66 to the reversing valve 64, and the spring 65 cavity is communicated with a T port through a second damping 67, so that the pressure of the a1 cavity is reduced. The displacement ratio of first main spool 51 and second main spool 52 is achieved.

That is, first main spool 51 moves to the left a certain distance, at this time, oil passage A1 communicates with oil passage A1B1' through first main spool 51, and oil passage B1 communicates with oil passage T through first main spool 51. The P1 oil passage passes through the first main spool 51, through the sixth check valve 63, and into the oil passage A1B1'. The oil passage A1B1' is communicated with the LS2 oil passage through a fifth one-way valve 62; second main spool 52 moves to the left a certain distance, at which time oil passage A2 communicates with oil passage A2B2' through second main spool 52, and oil passage B2 communicates with oil passage T through second main spool 52. The P1 oil passage passes through the second main spool 52, through the third check valve 60, and into the oil passage A2B2'. The oil passage A2B2' communicates with the LS2 oil passage through a fourth check valve 61. Compared with the two, the high-pressure oil channel LS2 is communicated, and the low-pressure check valve is reversely blocked.

Embodiment two:

based on the hydraulic system of the loader according to the first embodiment, the present embodiment provides a loader configured with the hydraulic system of the loader according to the first embodiment, wherein the oil inlet P of the energy-saving multi-way valve 8 may be connected to the second working port EF of the priority valve 4, or may be directly connected to the oil outlet of the variable pump 1. The LS port is connected to the LS3 port of the priority valve 4, or directly to the X port of the variable displacement pump 1. The port T and the port L are connected to the hydraulic tank 11.

The foregoing is merely a preferred embodiment of the present invention, and it should be noted that modifications and variations could be made by those skilled in the art without departing from the technical principles of the present invention, and such modifications and variations should also be regarded as being within the scope of the invention.

Claims

1. A loader hydraulic system, comprising: a variable pump (1), a priority valve (4), a steering gear (2) and an energy-saving multi-way valve (8); the variable pump (1) inputs hydraulic oil into the steering hydraulic cylinder (3) through the priority valve (4) and the steering gear (2) and is used for controlling the steering of the loader; the variable pump (1) inputs hydraulic oil into the first executive component (6) and the second executive component (7) through the priority valve (4) and the energy-saving multi-way valve (8) and is used for controlling the first executive component (6) and the second executive component (7) to complete single action or compound action; the LS2 port of the energy-saving multi-way valve (8) is connected with the LS3 port of the priority valve (4) and is used for controlling the steering hydraulic cylinder (3), the first executing element (6) and the second executing element (7) to complete single action or compound action.

2. The loader hydraulic system according to claim 1, characterized in that the energy-saving multi-way valve (8) comprises:

a first main valve core (51) for controlling the communication or disconnection of the input ports P1 and P2 and the output ports A1 and B1;

a second main valve core (52) for controlling the communication or disconnection of the input ports P1 and P2 and the output ports A2 and B2;

when the first main valve core (51) and the second main valve core (52) are not operated, the input oil ports P1 and P2 are separated from the output oil ports A1 and B1 through the first main valve core (51); the input oil ports P1 and P2 are separated from the output oil ports A2 and B2 through a second main valve core (52);

when the first main valve core (51) acts, hydraulic oil input by the input oil ports P1 and P2 enters a first bypass through a sixth one-way valve (63); the first bypass is connected with the output oil ports A1 and B1 through a first main valve core (51), and is fed back to the LS oil port through a fifth one-way valve (62);

when the second main valve core (52) acts, hydraulic oil input by the input oil ports P1 and P2 enters a second bypass through a third one-way valve (60); the second bypass is connected with the output oil ports A2 and B2 through the second main valve core (52), and is fed back to the LS oil port through the fourth one-way valve (61).

3. The hydraulic system of the loader according to claim 2, wherein the energy-saving multi-way valve (8) further comprises control ports a1, a2, b1, b2, the control port a1 being in communication with the right chamber end of the first main spool (51) for controlling the first main spool (51) to move left in the right position; the control oil port b1 is communicated with the left cavity end of the first main valve core (51) and is used for controlling the first main valve core (51) to move rightwards to be at a left position; the control oil port a2 is communicated with the right cavity end of the second main valve core (52) and is used for controlling the second main valve core (52) to move leftwards to be in a right position; the control oil port b2 is communicated with the left cavity end of the second main valve core (52) and is used for controlling the second main valve core (52) to move rightwards to be in a left one position or a left two position;

the control oil port a1 is communicated with an oil inlet of the reversing valve core (64) through a first damping (66), meanwhile, the oil inlet of the reversing valve core (64) is communicated with a right cavity end of the first main valve core (51), and an oil outlet of the reversing valve core (64) is communicated with a T port through a second damping (67); the control oil port a2 is communicated with the right control end of the reversing valve core (64), and the left side of the reversing valve core (64) is controlled by a spring (65) and is communicated with the T port.

4. A hydraulic loader system according to claim 3, characterized in that the outlet port B1 communicates with the outlet port B2 via a first check valve (57), a second check valve (59) for supplementing the rod-like cavities of the first and second actuators (6, 7).

5. The hydraulic system of the loader according to claim 4, further comprising a pilot oil source valve (5), wherein an oil inlet of the pilot oil source valve (5) is communicated with an Mp port of the energy-saving multi-way valve (8), an oil outlet of the pilot oil source valve (5) is sequentially connected with a two-way ball valve (12) and a pilot valve (13), and the pilot valve (13) is used for controlling the first main valve core (51) and the second main valve core (52) through control oil ports a1, a2, b1 and b 2.

6. The loader hydraulic system of claim 5, wherein the compound action comprises: the two-way ball valve (12) is rotated, so that the two-way ball valve (12) is switched from a first working position to a second working position, and control oil ports a1 and a2 of the energy-saving multi-way valve (8) are controlled by the pilot valve (13) to enable the first main valve core (51) and the second main valve core (52) to move leftwards; realizing the displacement ratio of the first main valve core (51) and the second main valve core (52) according to the pressure of the control oil port a 2; when the pressure of the control oil port a2 is regulated to be larger than the pressure set by the spring (65), the reversing valve core (64) is switched from the first working position to the second working position, at the moment, the pressure of the control oil port a1 passes through the first damping (66), the reversing valve core (64) and the second damping (67) are depressurized, so that the pressure of the right cavity end of the first main valve core (51) is reduced, and the position change of the first main valve core (51) is controlled; and according to the pressure of the control oil port a2, regulating and controlling the pressure reaching the right control end of the first main valve core (51) to form displacement matching of the first main valve core (51) and the second main valve core (52).

7. The loader hydraulic system of claim 5, wherein the compound action further comprises:

the first main valve core (51) and the second main valve core (52) are both reversed to the right, and an oil inlet of the first main valve core (51) is communicated with an output oil port A1 through a choke outlet of the sixth check valve (63) to the first main valve core (51); a fifth one-way valve (62) is communicated with the LS2 port so as to feed back a load pressure signal of the first actuator (6) to the LS2 port; an oil inlet of the second main valve core (52) is communicated with the output oil port A2 through a throttling port from the third one-way valve (60) to the second main valve core (52); the load pressure signal of the second execution element (7) is fed back to the LS2 port through the fourth one-way valve (61), the higher pressure is transmitted to the LS2 port after the two load feedback pressures are compared, and the lower pressure is cut off due to the one-way valve; the variable pump (1) is realized to provide flow according to the opening requirements of the first main valve core (51) and the second main valve core (52).

8. The loader hydraulic system of claim 5, wherein the compound action further comprises:

the first main valve core (51) moves leftwards to a certain distance, at the moment, the output oil port A1 is communicated with the first bypass through the first main valve core (51), and the output oil port B1 is communicated with the T port through the first main valve core (51); the input oil port P1 enters a first bypass through a first main valve core (51) and a sixth one-way valve (63); the first bypass is communicated with the LS2 port through a fifth one-way valve (62); the second main valve core (52) moves leftwards to a certain distance, at the moment, the output oil port A2 is communicated with the second bypass through the second main valve core (52), and the output oil port B2 is communicated with the T port through the second main valve core (52); the input oil port P1 enters a second bypass through a second main valve core (52) and a third one-way valve (60), the second bypass is communicated with the LS2 port through a fourth one-way valve (61), and compared with the second bypass and the first bypass, the high pressure is communicated with the LS2 port, and the low pressure is reversely cut off due to the one-way valve.

9. A loader, characterized in that the loader is provided with a loader hydraulic system according to any one of claims 1-8.