CN110541855A

CN110541855A - Hydraulic system of working device

Info

Publication number: CN110541855A
Application number: CN201910917221.8A
Authority: CN
Inventors: 汪立平; 哈良; 贾靖; 黄国和; 刘红光; 张国良; 韩俊翔; 翟莉
Original assignee: Jiangsu Hengli Hydraulic Technology Co Ltd
Current assignee: Jiangsu Hengli Hydraulic Technology Co Ltd
Priority date: 2019-09-26
Filing date: 2019-09-26
Publication date: 2019-12-06

Abstract

The invention relates to a hydraulic system of a working machine, in particular to a hydraulic system of a working device, which comprises: at least one hydraulic pump that discharges working oil; an actuator operated by a supply of working oil from the at least one hydraulic pump; the hydraulic control system further comprises a regeneration oil path, wherein the regeneration oil path is used for sending return oil serving as regeneration oil to a cavity of the actuator, wherein the cavity is in a negative pressure state, the return oil is working oil discharged from the actuator, a regeneration valve group is arranged on the regeneration oil path, and the regeneration valve group controls the on-off and flowing direction of the regeneration oil path; and a regeneration cutoff oil passage that sends the regeneration oil to another destination, the regeneration cutoff oil passage being provided with a regeneration cutoff valve. The hydraulic system solves the technical problems of complex regeneration and regeneration cut-off control structure, low adjustability and slow response existing in the hydraulic system in the prior art.

Description

hydraulic system of working device

Technical Field

The invention relates to a hydraulic system of a working machine, in particular to a hydraulic system of a working device.

Background

in the current engineering machinery, the excavator is greatly popularized and applied in use, and the oil consumption, the working efficiency and the operation convenience of the excavator are main attention objects of various host manufacturing companies, research and development mechanisms and customers. The excavator working device comprises a movable arm, an arm, a bucket and a working device hydraulic pipeline including a movable arm oil cylinder, an arm oil cylinder and a bucket oil cylinder, wherein the arm is used as an important component of the excavator working device, and the reasonable arrangement of a hydraulic system of the arm is of great significance to the working performance of the excavator.

In the prior art, the operation efficiency of the bucket rod is improved by converging two hydraulic pumps to realize the action of the bucket rod, the two hydraulic pumps are respectively provided with a bucket rod valve correspondingly, a regeneration oil way is arranged in a bucket rod valve core, and the regeneration of a small cavity of the bucket rod to a large cavity is realized through the regeneration oil way. When the inside of the bucket rod is perpendicular to the ground, the excavation operation is required, regeneration is cut off by a regeneration cut-off valve or an integrated valve on a valve core, and the excavation force is improved by releasing the load pressure on the oil return side. However, if a plug-in regeneration cut-off valve is adopted, the regeneration cut-off function cannot be adjusted; however, if the valve core is integrated with the regeneration and regeneration cut-off one-way valve, the structure is complex, and because the regeneration and regeneration cut-off are integrated on the same valve core, a control blind spot can occur when the regeneration and regeneration are cut off, and the responsiveness can be affected.

Disclosure of Invention

The invention provides a hydraulic system of a working device, which aims to solve the technical problems of complicated regeneration and regeneration cut-off control structure, low adjustability and slow response existing in the hydraulic system in the prior art. The technical scheme of the invention is as follows:

A hydraulic system of a work apparatus, comprising: at least one hydraulic pump that discharges working oil; an actuator operated by a supply of working oil from the at least one hydraulic pump; the hydraulic control system further comprises a regeneration oil path, wherein the regeneration oil path is used for sending return oil serving as regeneration oil to a cavity of the actuator, wherein the cavity is in a negative pressure state, the return oil is working oil discharged from the actuator, a regeneration valve group is arranged on the regeneration oil path, and the regeneration valve group controls the on-off and flowing direction of the regeneration oil path; and a regeneration cutoff oil passage that sends the regeneration oil to another destination, the regeneration cutoff oil passage being provided with a regeneration cutoff valve.

The regeneration oil way and the regeneration cut-off oil way are arranged, the regeneration valve is arranged on the regeneration oil way, the regeneration cut-off valve is arranged on the regeneration cut-off oil way, the working oil discharged from the cavity II flows to the cavity I through the regeneration oil way, so that the regeneration utilization is realized, and the working condition of the regeneration oil way is controlled by the regeneration valve; when cavity I need not the regeneration oil, the regeneration oil can cut off the oil circuit through the regeneration to other destinations. Compared with the prior art, the regeneration valve and the regeneration cut-off valve are not required to be integrated on the pumping control valve of the hydraulic pump, regeneration and regeneration cut-off control are simplified, the adjusting performance is good, and the responsiveness is fast.

Furthermore, the number of the hydraulic pumps is two, pump outlets of the two hydraulic pumps are respectively provided with a control valve, and the two hydraulic pumps can be combined to respectively supply oil to the two cavities of the actuator under the control of the control valves. The oil is supplied to the cavity II or the cavity I through confluence, and the bucket rod is quick in response.

Further, two cavities of the actuator are respectively a cavity I and a cavity II, the cavity I is communicated with a first working oil path, the cavity II is communicated with a second working oil path, and each hydraulic pump is respectively communicated with the first working oil path and the second working oil path under the control of the control valve.

Further, both ends of the regeneration oil passage are respectively communicated with the second working oil passage and the first working oil passage.

further, two hydraulic pumps are hydraulic pump IP 1 and hydraulic pump IIP 2 respectively, hydraulic pump IP 1 is cavity I and II fuel supplies oil of cavity respectively under control of control valve I, control valve I includes pressure hydraulic fluid port P1, oil return port T1, regeneration cut off hydraulic fluid port c and two working fluid ports a1, b1, pressure hydraulic fluid port P1 with hydraulic pump IP 1's pump export intercommunication, oil return port T1 with oil return tank T intercommunication, two working fluid ports a1, b1 respectively with first working oil circuit and second working oil circuit intercommunication, regeneration cut off hydraulic fluid port c with regeneration cut off the oil circuit intercommunication.

Further, hydraulic pump IIP 2 switches on with first working oil circuit, second working oil circuit respectively under control valve II's control, control valve II includes pressure hydraulic fluid port P2, oil return port T2 and two working fluid ports a2, b2, pressure hydraulic fluid port P2 with hydraulic pump IIP 2's pump mouth intercommunication, oil return port T2 with oil return tank T intercommunication, two working fluid ports a2, b2 respectively with first working oil circuit and second working oil circuit intercommunication.

Furthermore, the control valve I and the control valve II are both provided with a middle position and two working positions, when the control valve I and the control valve II are both positioned at the first working position, the two hydraulic pumps are converged to supply oil to the cavity I, and the working oil discharged from the cavity II is regenerated to the cavity I through a regeneration oil path and/or is circulated to the regeneration cut-off oil path through the control valve I so as to be conveyed to other destinations; when the two control valves are located at the second working position, the two hydraulic pumps are converged into the cavity II to supply oil, and the hydraulic oil discharged from the cavity I can return oil through the two control valves.

through setting up control valve I, control valve II and two working oil circuit, can realize that two hydraulic pumps confluence are cavity II or I fuel feeding of cavity, and the hydraulic oil that cavity I was let out can directly get back to back oil tank through the control valve, realizes no back pressure oil return, fuel consumption and pressure loss are reduced.

further, the control valve i is replaced by a control valve iii, the control valve iii includes a pressure port P3, an oil return port T3 and two working ports a3 and b3, the pressure port P3 is communicated with a pump outlet of the hydraulic pump ip 1, the oil return port T3 is communicated with the oil return tank T, and the two working ports a3 and b3 are respectively communicated with the first working oil path and the second working oil path.

When the control valve III and the control valve II are both positioned at the first working position, the two hydraulic pumps are converged to supply oil to the cavity I, and the working oil discharged from the cavity II is regenerated to the cavity I through a regeneration oil way or is conveyed to other destinations through a regeneration cut-off oil way; when the control valve III and the control valve II are both located at the second working position, the two hydraulic pumps are converged to supply oil to the cavity II, and hydraulic oil discharged from the cavity I can return oil through the control valve III and the control valve II.

further, the regeneration shutoff oil passage communicates with the second hydraulic oil passage.

Based on the technical scheme, the invention can realize the following technical effects:

1. According to the hydraulic system of the working device, the regeneration oil path and the regeneration cut-off oil path are arranged, the regeneration valve is arranged on the regeneration oil path, the regeneration cut-off valve is arranged on the regeneration cut-off oil path, the working oil discharged from the cavity II flows to the cavity I through the regeneration oil path, so that the regeneration is realized, and the working condition of the regeneration oil path is controlled by the regeneration valve; when cavity I need not the regeneration oil, the regeneration oil can cut off the oil circuit through the regeneration to other destinations. Compared with the prior art, the regeneration valve and the regeneration cut-off valve are separately arranged and control the corresponding oil way, and are not required to be integrated on a control valve of a hydraulic pump, so that the regeneration and regeneration cut-off control is simplified, and the pressure is reduced; the regeneration cut-off valve is controlled by a slide valve, and the valve core is driven to move by adopting hydraulic control, electric control or other modes to control the regeneration flow and the oil return flow, so that the accurate control of the regeneration amount and the oil return amount can be achieved. The responsiveness and controllability of regeneration are improved. Meanwhile, regeneration is independently controlled, so that a regeneration oil path is simplified, and oil consumption is reduced;

2. according to the hydraulic system of the working device, the oil way is reasonably arranged, two hydraulic pumps can be converged into a cavity II and a cavity I of the actuator to supply oil, and the response is fast; when the two hydraulic pumps are converged to supply oil to the cavity I, working oil discharged from the cavity II can be regenerated to the cavity I as regenerated oil under the action of potential energy, so that the confluence of the two hydraulic pumps and the regenerated oil is realized; when regeneration confluence is not needed, working oil discharged from the cavity II can be directly conveyed to other destinations through a regeneration cut-off oil way or conveyed to other destinations through the regeneration cut-off oil way after passing through the control valve I; when two hydraulic pumps are converged to supply oil to the cavity II, oil drainage of the cavity I directly returns oil through two control valves for controlling the two hydraulic pumps, so that back pressure-free oil return is realized, and oil consumption and pressure loss are reduced. In addition, the regeneration cut-off valve can be set to be a valve with any opening, so that in the regeneration confluence process, part of the regenerated oil can return through the regeneration cut-off oil way by controlling the opening of the regeneration cut-off valve, and further the oil flux of the regenerated oil to the cavity I is controlled, the oil flux of the regenerated oil to the cavity I can be controlled only by adjusting the oil flux of the regeneration cut-off oil way in the adjustment process, and the adjustment process is simple and controllable;

3. The hydraulic system of the working device can realize the functions of confluence oil supply, regeneration cut-off and main valve element oil return under the condition of using less hydraulic valves, and can realize independent accurate control of regeneration and regeneration cut-off.

Drawings

fig. 1 is a schematic diagram of a hydraulic system according to a first embodiment of the present invention;

FIG. 2 is a traveling diagram of an oil path when the regenerative confluence of the hydraulic system of the first embodiment is used for supplying oil to the cavity I;

FIG. 3 is a schematic diagram of the oil path when the hydraulic system of the first embodiment is cut off to supply oil to the cavity I in a regeneration mode;

FIG. 4 is a direction diagram of an oil path when the hydraulic system of the first embodiment merges into the cavity II for supplying oil;

FIG. 5 is a schematic illustration of a hydraulic system according to a second embodiment of the present invention;

FIG. 6 is a traveling diagram of an oil path when the regenerative confluence of the hydraulic system of the second embodiment is used for supplying oil to the cavity I;

FIG. 7 is a schematic diagram of the oil path during the regeneration and cut-off of the hydraulic system of the second embodiment to supply oil to the cavity I;

FIG. 8 is a direction diagram of the oil path when the hydraulic system of the second embodiment merges into the cavity II for supplying oil;

In the figure: 1-regeneration oil circuit; 11-a regeneration valve group; 111-opening and closing valves; 112-a one-way valve; 2-regenerating and cutting off an oil way; 21-a regeneration cut-off valve; 31-a first pumping circuit; 32-second pumping oil circuit; 41-control valve I; 42-control valve II; 43-control valve III; 5-a first working oil path; 6-a second working oil way; 61-control valve IV; 7-an actuator; 71-Cavity I; 72-Chamber II; the non-closed arrow indicates the oil inlet trend; the closed arrow indicates the drainage direction.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

in the description of the present invention, it is to be understood that the orientation or positional relationship indicated by the orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc. are usually based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and in the case of not making a reverse description, these orientation words do not indicate and imply that the device or element being referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore, should not be considered as limiting the scope of the present invention; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

It should be noted that the terms "first", "second", and the like are used to define the components, and are only used for convenience of distinguishing the corresponding components, and the terms have no special meanings unless otherwise stated, and therefore, the scope of the present invention should not be construed as being limited.

example one

As shown in fig. 1 to 4, the present embodiment provides a hydraulic system of a working device including at least one hydraulic pump that discharges working oil and an actuator 7; the actuator is operated by a supply of working oil from the at least one hydraulic pump.

The actuator 7 can be a hydraulic cylinder which is provided with a cavity I71 and a cavity II 72, and at least one hydraulic pump supplies oil to the cavity I71 or the cavity II 72 to drive the actuator 7 to work. Specifically, a first working oil path 5 is communicated with a cavity I71 of the actuator 7, and working oil pumped by at least one hydraulic pump enters the cavity I71 of the actuator 7 through the first working oil path 5; the cavity II 72 of the actuator 7 is communicated with the second working oil path 6, and the working oil pumped by at least one hydraulic pump enters the cavity II 72 of the actuator 7 through the second working oil path 6. Preferably, the second working fluid passage 6 is further provided with a control valve iv 61, and the control valve iv 61 is used for controlling the working fluid pumped by the two hydraulic pumps to enter the cavity ii 72 or drain the working fluid from the cavity ii 72 to the regeneration fluid passage 1 and/or the regeneration cut-off fluid passage 2. Preferably, the control valve iv 61 is a holding valve, and by setting the control valve iv to be the holding valve, when the two hydraulic pumps stop supplying oil to the actuator 7, leakage of the spool valve can be avoided, and the working device is prevented from naturally falling, so that the working device can be held in place.

In this embodiment, there are two hydraulic pumps, i.e. a hydraulic pump ip 1 and a hydraulic pump ii P2, the hydraulic pump ip 1 supplies oil to the cavity i 71 and the cavity ii 72 respectively under the control of the control valve i 41, and the hydraulic pump ii P2 supplies oil to the cavity i 71 and the cavity ii 72 respectively under the control of the control valve ii 42. The hydraulic pump IP 1 and the hydraulic pump IIP 2 can be combined to supply oil to the cavity I71 or II 72.

Specifically, the pump outlet of the hydraulic pump ip 1 is communicated with a first pumping oil path 31, and the hydraulic pump ip 1 is communicated with the control valve i 41 through the first pumping oil path 31. The control valve I41 is a three-position five-way valve, the control valve I41 is provided with 5 oil ports which are respectively a pressure oil port P1, an oil return port T1, a regeneration cut-off oil port c, a working oil port a1 and a working oil port b1, the pump outlet of the hydraulic pump I P1 is communicated with the pressure oil port P1 through a first pumping oil way 31, the oil return port T1 is communicated with an oil return box T, the regeneration cut-off oil port c is communicated with a regeneration cut-off oil way 2, the working oil port a1 is communicated with a first working oil way 5, and the working oil port b1 is communicated with a second working oil way 6.

The control valve I41 has a neutral position and two working positions. When the control valve I41 is positioned in the middle position, 5 oil ports are not communicated; when the control valve i 41 is located at the first working position (i.e., the right position in fig. 1), the pressure port p1 is communicated with the working port a1, and the working port b1 is communicated with the regeneration cutoff oil path 2; when the control valve i 41 is located at the second working position (i.e., the left position in fig. 1), the pressure port p1 is communicated with the working port b1, and the working port a1 is communicated with the oil return port t 1. When the control valve I41 is located at the first working position, the hydraulic pump IP 1 can supply oil to the cavity I71; when the control valve I41 is positioned at the middle position, the hydraulic pump I P1 does not supply oil to the cavity I71 and the cavity II 72; when the control valve I41 is located at the second working position, the hydraulic pump IP 1 can supply oil to the cavity II 72, and the hydraulic oil discharged from the cavity I71 can return to the oil return tank T through the control valve I41. The control valve I41 can be a three-position five-way valve controlled by an electric control, a hydraulic control, an electro-hydraulic control or other servo motors.

the pump outlet of the hydraulic pump IIP 2 is communicated with a second pumping oil path 32, and the hydraulic pump IIP 2 is communicated with a control valve II 42 through the second pumping oil path 32. The control valve II 42 is a three-position four-way valve, 4 oil ports are arranged on the control valve II 42 and respectively comprise a pressure oil port P2, an oil return port T2, a working oil port a2 and a working oil port b2, the pump outlet of the hydraulic pump II P2 is communicated with the pressure oil port P2 through a second pumping oil path 32, the oil return port T2 is communicated with an oil return tank T, the working oil port a2 is communicated with a first working oil path 5, and the working oil port b2 is communicated with a second working oil path 6.

The control valve II 42 has a neutral position and two working positions. When the control valve II 42 is positioned at the middle position, the four oil ports are not communicated; when the control valve II 42 is located at the first working position (namely, the left position in FIG. 1), the pressure oil port p2 is communicated with the working oil port a2, and the working oil port b2 is disconnected from the oil return port t 2; when the control valve ii 42 is in the second working position (i.e., the right position in fig. 1), the pressure port p2 is communicated with the working port b2, and the working port a2 is communicated with the oil return port t 2. When the control valve II 42 is positioned at the first working position, the hydraulic pump II P2 can supply oil to the cavity I71; when the control valve II 42 is positioned at the middle position, the hydraulic pump II P2 does not supply oil to the cavity II 72 and the cavity I71; when the control valve II 42 is located at the second working position, the hydraulic pump IIP 2 can supply oil to the cavity II 72, and hydraulic oil leaked out from the cavity I71 can return to the oil return tank T through the control valve II 42. The control valve II 42 can be a three-position four-way valve controlled by an electric control, a hydraulic control, an electro-hydraulic control or other servo motors.

by controlling the control valve I41 and the control valve II 42 to be located at the first working position, the hydraulic pump I P1 and the hydraulic pump II P2 can be converged into the cavity I71 of the actuator 7 to supply oil; by controlling the control valve I41 and the control valve II 42 to be located at the second working position, the hydraulic pump IP 1 and the hydraulic pump II P2 can be converged into the cavity II 72 of the actuator 7 for oil supply, at the moment, hydraulic oil discharged from the cavity I71 can return to the oil return tank T through the control valve I41 and the control valve II 42, and back-pressure-free oil return of the cavity I71 is achieved.

Preferably, the first pumping oil path 31 is provided with a first check valve, and the pressure oil pumped by the hydraulic pump ip 1 can only flow to the pressure port P1 in one way through the first pumping oil path 31; the second pumping oil path 32 is provided with a second check valve, and the pressure oil pumped by the hydraulic pump iip 2 can only flow to the pressure port P2 in one direction through the second pumping oil path 32.

The hydraulic system of the present embodiment further includes a regenerative oil passage 1, and the regenerative oil passage 1 is for sending return oil, which is working oil that is drained from a chamber ii 72 of the actuator 7, to the chamber i 71 of the actuator 7 as regenerative oil. The regeneration oil path 1 is provided with a regeneration valve group 11, and the regeneration valve group 11 is used for controlling the circulation direction and the on-off of the regeneration oil on the regeneration oil path 1. Specifically, two ends of the regeneration oil path 1 are respectively communicated with the first working oil path 5 and the second working oil path 6, the regeneration valve group 11 includes an on-off valve 111 and a check valve 112, the on-off valve 111 can be a two-position two-way valve for controlling on-off of the regeneration oil path 1, the check valve 112 controls the direction of the regeneration oil path 1, hydraulic oil on the second working oil path 6 can flow to the first working oil path 5 through the check valve 112, but hydraulic oil on the first working oil path 5 cannot flow to the second working oil path 6 through the regeneration oil path 1. Preferably, the opening and closing valve 111 and the check valve 112 are provided in series, and the opening and closing valve 111 is located upstream of the check valve 112. The on-off valve 111 and the check valve 112 may be integrally provided, and the check valve 112 may be integrally provided on a valve body of the on-off valve 111.

The hydraulic system of the present embodiment further includes a regeneration-cut oil passage 2, and the regeneration-cut oil passage 2 sends the regenerated oil to other destinations. Specifically, the regeneration cutoff oil passage 2 communicates with a regeneration cutoff oil port c of the control valve i 41. When regeneration needs to be cut off or the amount of regenerated oil needs to be adjusted, at least part of regenerated oil discharged from the cavity II 72 can flow to the regeneration cut-off oil passage 2 through the control valve I41 and is sent to other destinations.

further, the regeneration cutoff oil passage 2 is provided with a regeneration cutoff valve 21, and the regeneration cutoff valve 21 can control the on/off of the regeneration cutoff oil passage 2. Preferably, the regeneration cut-off valve 21 is a two-position two-way valve. Further preferably, the regeneration cut valve 21 is a valve that can be adjusted to an arbitrary opening degree. When the regeneration is required to be cut off, the regeneration oil path 1 can be disconnected, the regeneration cutting oil path 2 is communicated, and the regenerated oil discharged from the cavity II 72 can flow to the regeneration cutting oil path 2 through the control valve I41 and is sent to other destinations; when the regeneration oil amount needs to be adjusted, the regeneration oil path 1 can be communicated, and the oil flux of the regeneration oil passing through the regeneration cut-off oil path 2 is adjusted by adjusting the opening degree of the regeneration cut-off valve 21 so as to adjust the oil flux of the regeneration oil path 1. Wherein other destinations may be selected but not limited to the return tank T.

Preferably, the opening and closing valve 111 and the control valve iv 61 in the present embodiment may be electrically controlled, hydraulically controlled, electro-hydraulically controlled, or other servo motor controlled pilot operated valves.

Preferably, the actuator 7 in this embodiment is a hydraulic pump, the chamber i 71 is a rodless chamber, and the chamber ii 72 is a rod chamber. Besides, the actuator 7 can be reversely arranged, the cavity I71 is a rod cavity, the cavity II 72 is a rodless cavity, and only the functions of driving the working device to retract and swing outwards can be achieved.

In the hydraulic system of the working device according to the embodiment, the working device may be an arm of an excavator, and the hydraulic system according to the embodiment may be used to control the operation of the arm of the excavator. Based on the above structure, taking the arm work of driving the excavator as an example, the operating principle of the hydraulic system of the embodiment is as follows:

In the initial state, the control valve I41 and the control valve II 42 are both positioned in the middle position, and the two hydraulic pumps do not supply oil to the actuator 7;

As shown in fig. 2, in the early stage of retraction of the arm, when the excavator is not yet performing excavation work, the control valve i 41 and the control valve ii 42 are both located at the first working position, the hydraulic pump ip 1 and the hydraulic pump ii P2 merge and enter the cavity i 71 through the first working oil path 5, meanwhile, the regeneration oil discharged from the cavity ii 72 flows to the first working oil path 5 through the regeneration oil path 1, and the regeneration oil and the oil pumped by the two hydraulic pumps merge to supply oil to the cavity i 71. In the stage, the regeneration oil path 1 is communicated, the regeneration cut-off oil path 2 is disconnected, and the regeneration oil flows to the first working oil path 5 to be merged with the pumped oil to supply oil to the cavity I71; in the process, the oil flux of the regenerated oil regenerated to the cavity I71 can be controlled by adjusting the opening of the regeneration cut-off valve 21;

As shown in fig. 3, in the later stage of retraction of the arm, that is, when the arm is received in a position perpendicular to the ground, the control valve i 41 and the control valve ii 42 are both located at the first working position, and the hydraulic pump ip 1 and the hydraulic pump ii P2 merge to enter the cavity i through the first working oil path 5; meanwhile, the regeneration oil path 1 is disconnected, the regeneration cut-off oil path 2 is communicated, and the regeneration oil discharged from the cavity II 72 flows to the regeneration cut-off oil path 2 through the control valve I41 and is conveyed to other destinations. Regeneration and cutting are performed, and the digging pressure loss of the bucket rod is reduced.

As shown in fig. 4, in the outward swinging process of the bucket rod, the control valve i 41 and the control valve ii 42 are both located at the second working position, the hydraulic pump ip 1 and the hydraulic pump ii P2 jointly flow through the second working oil path 6 and enter the cavity ii 72, and the cavity ii 72 enters oil; meanwhile, hydraulic oil discharged from the cavity I71 returns to the oil return tank T through the control valve I41 and the control valve II 42.

example two

As shown in fig. 5 to 8, the present embodiment is substantially the same as the first embodiment except that in the present embodiment, the control valve i 41 is replaced with a control valve iii 43, and the position of the regeneration-cut oil passage 2 is different from the first embodiment.

Specifically, the control valve iii 43 is a three-position four-way valve, the control valve iii 43 has 4 oil ports, which are a pressure oil port P3, an oil return port T3, a working oil port a3 and a working oil port b3, respectively, the pump outlet of the hydraulic pump ip 1 is communicated with the pressure oil port P3 through a first pumping oil path 31, the oil return port T3 is communicated with an oil return tank T, the working oil port a3 is communicated with a first working oil path 5, and the working oil port b3 is communicated with a second working oil path 6.

The control valve iii 43 has a neutral position and two working positions. When the control valve III 43 is located at the middle position, the four oil ports are not communicated; when the control valve iii 43 is located at the first working position (i.e., the right position in fig. 5), the pressure port p1 is communicated with the working port a3, and the working port b3 is disconnected from the oil return port t 3; when the control valve iii 43 is located at the second operating position (i.e., the left position in fig. 5), the pressure port p1 communicates with the working port b3, and the working port a3 communicates with the oil return port t 3. When the control valve III 43 is located at the first working position, the hydraulic pump IP 1 can supply oil to the cavity I71; when the control valve III 43 is positioned at the middle position, the hydraulic pump IP 1 does not supply oil to the cavity II 72 and the cavity I71; when the control valve III 43 is located at the second working position, the hydraulic pump IP 1 can supply oil to the cavity II 72, and hydraulic oil discharged from the cavity I71 can return to the oil return tank T through the control valve III 43. Preferably, control valve iii 43 may be an electrically, hydraulically, electro-hydraulically or other servo-motor controlled three-position four-way valve.

by controlling the control valve III 43 and the control valve II 42 to be located at the first working position, the hydraulic pump I P1 and the hydraulic pump II P2 can be converged into the cavity I71 of the actuator 7 to supply oil; by controlling the control valve III 43 and the control valve II 42 to be located at the second working position, the hydraulic pump IP 1 and the hydraulic pump II P2 can be converged into the cavity II 72 of the actuator 7 for oil supply, at the moment, hydraulic oil discharged from the cavity I71 can return to the oil return tank T through the control valve III 43 and the control valve II 42, and back-pressure-free oil return of the cavity I71 is achieved.

The regeneration cutoff oil passage 2 communicates with the second hydraulic oil passage 6. The oil drainage of the cavity II 72 can be communicated to the regeneration cut-off oil passage 2 through the second working oil passage 6. In addition, when the two hydraulic pumps are merged to supply oil to the chamber ii 72, the oil flow rate for supplying oil to the chamber ii 72 can be controlled by the regenerative cutoff oil passage 2.

Based on above-mentioned structure, when the hydraulic system of this embodiment is used for the excavator dipper, its theory of operation is:

In the initial state, the control valve III 43 and the control valve II 42 are both positioned in the middle position, and the two hydraulic pumps do not supply oil to the actuator 7;

As shown in fig. 6, in the early stage of retraction of the arm, when the excavator is not yet performing excavation work, the control valve iii 43 and the control valve ii 42 are both located at the first working position, the hydraulic pump ip 1 and the hydraulic pump ii P2 merge and enter the cavity i 71 through the first working oil path 5, at the same time, the regeneration oil discharged from the cavity ii 72 flows to the first working oil path 5 through the regeneration oil path 1, and the regeneration oil and the oil pumped by the two hydraulic pumps merge and supply the oil to the cavity i 71. In the stage, the regeneration oil path 1 is communicated, the regeneration cut-off oil path 2 is disconnected, and the regeneration oil flows to the first working oil path 5 to be combined with the pumped oil to supply oil to the cavity I; in the process, the oil flux of the regenerated oil regenerated to the cavity I71 can be controlled by adjusting the opening of the regeneration cut-off valve 21;

As shown in fig. 7, in the later stage of retraction of the arm, that is, when the arm is received to be perpendicular to the ground, the control valve iii 43 and the control valve ii 42 are both located at the first working position, and the hydraulic pump ip 1 and the hydraulic pump ii P2 merge to enter the cavity i through the first working oil path 5; meanwhile, the regeneration oil path 1 is disconnected, the regeneration cut-off oil path 2 is communicated, and the regeneration oil discharged from the cavity II 72 flows to the regeneration cut-off oil path 2 through the second working oil path 6 and is conveyed to other destinations. Regeneration and cutting are performed, and the digging pressure loss of the bucket rod is reduced.

As shown in fig. 8, in the outward swinging process of the boom, the control valve i 41 and the control valve ii 42 are both located at the second working position, the hydraulic pump ip 1 and the hydraulic pump ii P2 jointly flow through the second working oil path 6 and enter the cavity ii 72, and the cavity ii 72 enters oil; meanwhile, hydraulic oil discharged from the cavity I71 returns to the oil return tank T through the control valve I41 and the control valve II 42.

The embodiments of the present invention have been described in detail with reference to the drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the gist of the present invention.

Claims

1. A hydraulic system of a work apparatus, comprising:

At least one hydraulic pump that discharges working oil;

An actuator (7) operated by a supply of working oil from the at least one hydraulic pump;

It is characterized in that the preparation method is characterized in that,

the hydraulic control system is characterized by further comprising a regeneration oil path (1), wherein the regeneration oil path (1) is used for sending return oil serving as regeneration oil to a cavity of the actuator (7) which is in a negative pressure state, the return oil is working oil leaked from the actuator (7), a regeneration valve group (11) is arranged on the regeneration oil path (1), and the regeneration valve group (11) controls the on-off and flowing direction of the regeneration oil path (1);

And a regeneration cutoff oil path (2), wherein the regeneration cutoff oil path (2) sends the regeneration oil to other destinations, and a regeneration cutoff valve (21) is arranged on the regeneration cutoff oil path (2).

2. the hydraulic system of a working device according to claim 1, wherein the hydraulic pumps are two, and the pump outlets of the two hydraulic pumps are respectively provided with a control valve, and the two hydraulic pumps can be combined to respectively supply oil to the two cavities of the actuator (7) under the control of the control valves.

3. the hydraulic system of a working device according to claim 2, wherein the two cavities of the actuator are a cavity I (71) and a cavity II (72), the cavity I (71) is communicated with the first working oil path (5), the cavity II (72) is communicated with the second working oil path (6), and each hydraulic pump is communicated with the first working oil path (5) and the second working oil path (6) under the control of a control valve.

4. The hydraulic system of a working device according to claim 3, wherein both ends of the regeneration oil passage (1) communicate with the second working oil passage (6) and the first working oil passage (5), respectively.

5. The hydraulic system of a working device according to claim 4, wherein the two hydraulic pumps are a hydraulic pump ip 1 and a hydraulic pump ii P2, the hydraulic pump ip 1 supplies oil to the cavity i (71) and the cavity ii (72) under the control of a control valve i (41), the control valve i (41) includes a pressure port P1, an oil return port T1, a regeneration cut-off port c and two working ports a1 and b1, the pressure port P1 is communicated with the pump outlet of the hydraulic pump ip 1, the oil return port T1 is communicated with the oil return tank T, the two working ports a1 and b1 are communicated with the first working oil passage (5) and the second working oil passage (6), and the regeneration cut-off port c is communicated with the regeneration cut-off oil passage (2).

6. The hydraulic system of a working device according to claim 5, wherein a hydraulic pump IIP 2 is respectively communicated with the first working oil path (5) and the second working oil path (6) under the control of a control valve II (42), the control valve II (42) comprises a pressure port P2, an oil return port T2 and two working oil ports a2 and b2, the pressure port P2 is communicated with a pump outlet of the hydraulic pump II P2, the oil return port T2 is communicated with the oil return tank T, and the two working oil ports a2 and b2 are respectively communicated with the first working oil path (5) and the second working oil path (6).

7. the hydraulic system of a working device according to claim 6, wherein the control valve I (41) and the control valve II (42) each have a neutral position and two working positions, and when the control valve I (41) and the control valve II (42) are both located at the first working position, the two hydraulic pumps are merged to supply oil to the chamber I (71), and the working oil discharged from the chamber II is regenerated to the chamber I (71) through the regeneration oil passage (1) and/or circulated to the regeneration cutoff oil passage (2) through the control valve I (71) and then delivered to other destinations; when the two control valves are both positioned at the second working position, the two hydraulic pumps are converged into the cavity II (72) for supplying oil, and the hydraulic oil discharged from the cavity I (71) can return oil through the two control valves.

8. The hydraulic system of a working device according to any one of claims 5 to 7, wherein the control valve I (41) is replaced by a control valve III (43), the control valve III (43) comprises a pressure port P3, a return port T3 and two working ports a3 and b3, the pressure port P3 is communicated with a pump outlet of the hydraulic pump IP 1, the return port T3 is communicated with the return tank T, and the two working ports a3 and b3 are respectively communicated with the first working oil path (5) and the second working oil path (6).

9. the hydraulic system of a working device according to claim 8, wherein the control valve iii (43) has a neutral position and two working positions, when the control valve iii (43) and the control valve ii (42) are both located at the first working position, the two hydraulic pumps are merged to supply oil to the chamber i (71), and the working oil discharged from the chamber ii (72) is regenerated to the chamber i (72) through the regeneration oil passage (1) or is delivered to other destinations through the regeneration cutoff oil passage (2); when the control valve III (43) and the control valve II (42) are both located at the second working position, the two hydraulic pumps are converged to supply oil to the cavity II (72), and hydraulic oil discharged from the cavity I (71) can return oil through the control valve III (43) and the control valve II (42).

10. The hydraulic system of a working device according to claim 8, wherein the regeneration-cut oil passage (2) communicates with the second working oil passage (6).