Hydraulic system of a working device

Abstract

The present invention relates to a hydraulic system of a working machine, and specifically to a hydraulic system of a working device, comprising: at least one hydraulic pump, which sprays working oil; an actuator, which works by supplying working oil from the at least one hydraulic pump; a regeneration oil circuit, which is used to send return oil as regeneration oil to a negative pressure cavity of the actuator, wherein the return oil is working oil leaked from the actuator, and a regeneration valve group is provided on the regeneration oil circuit, wherein the regeneration valve group controls the on-off and flow direction of the regeneration oil circuit; and a regeneration cut-off oil circuit, wherein the regeneration cut-off oil circuit sends the regeneration oil to other destinations, and a regeneration cut-off valve is provided on the regeneration cut-off oil circuit. The technical problems of complex regeneration and regeneration cut-off control structure, low adjustability, and slow responsiveness existing in the hydraulic system in the prior art are solved.

Description

Technical Field

[0001] The invention relates to a hydraulic system of an operating machine, and in particular to a hydraulic system of a working device. Background Art

[0002] Among the current construction machinery, the use of excavators has been greatly promoted and applied. Its fuel consumption, work efficiency and ease of operation are the main concerns of various host manufacturers, research and development institutions and customers. The working device of the excavator is composed of the boom, bucket, bucket and the hydraulic pipeline of the working device including the boom cylinder, bucket cylinder and bucket cylinder. The bucket is an important component of the working device of the excavator. The reasonable setting of its hydraulic system is of great significance to the working performance of the excavator.

[0003] In the prior art, the operation efficiency of the boom is generally improved by merging two hydraulic pumps to realize the movement of the boom. The two hydraulic pumps correspond to boom valves respectively, and a regeneration oil circuit is set in the boom valve core to realize the regeneration of the small boom cavity to the large cavity through the regeneration oil circuit. When the boom is received vertically to the ground, excavation is required at this time, and the regeneration is cut off by the plug-in regeneration cut-off valve or the integrated valve on the valve core. The regeneration is cut off by regeneration, and the load pressure on the return oil side is released to increase the excavation force. However, if a plug-in regeneration cut-off valve is used, the regeneration cut-off function cannot be adjusted; but if a regeneration and regeneration cut-off one-way valve integrated on the valve core is used, the structure is complicated, and because the regeneration and regeneration cut-off are integrated on the same valve core, there will be a control blind spot for regeneration and regeneration cut-off, and the responsiveness will be affected. Summary of the invention

[0004] In order to solve the technical problems of complex regeneration and regeneration cut-off control structure, low adjustability and slow responsiveness in the hydraulic system in the prior art, the present invention proposes a hydraulic system of a working device to solve the above technical problems. The technical solution of the present invention is as follows:

[0005] A hydraulic system of a working device comprises: at least one hydraulic pump, which sprays working oil; an actuator, which works by the supply of working oil from the at least one hydraulic pump; a regeneration oil circuit, which is used to send return oil as regeneration oil to a negative pressure cavity of the actuator, wherein the return oil is the working oil leaked from the actuator, and a regeneration valve group is provided on the regeneration oil circuit, and the regeneration valve group controls the on-off and flow direction of the regeneration oil circuit; a regeneration cut-off oil circuit, which sends the regeneration oil to other destinations, and a regeneration cut-off valve is provided on the regeneration cut-off oil circuit.

[0006] By setting up a regeneration oil circuit and a regeneration cut-off oil circuit, a regeneration valve is set on the regeneration oil circuit, and a regeneration cut-off valve is set on the regeneration cut-off oil circuit, the working oil leaked from cavity II flows to cavity I through the regeneration oil circuit to achieve regeneration, and the regeneration valve controls the working condition of the regeneration oil circuit; when cavity I does not need regeneration oil, the regeneration oil can be sent to other destinations through the regeneration cut-off oil circuit. Compared with the existing technology, the regeneration valve and the regeneration cut-off valve do not need to be integrated on the pumping control valve of the hydraulic pump, which simplifies the regeneration and regeneration cut-off control, has good adjustment performance, and fast responsiveness.

[0007] Furthermore, there are two hydraulic pumps, and the pump outlets of the two hydraulic pumps are respectively provided with control valves. Under the control of the control valves, the two hydraulic pumps can merge to supply oil to the two cavities of the actuator respectively. By merging to supply oil to cavity II or cavity I, the arm responds quickly.

[0008] Furthermore, the two cavities of the actuator are cavity I and cavity II, cavity I is connected to the first working oil circuit, and cavity II is connected to the second working oil circuit. Each hydraulic pump is connected to the first working oil circuit and the second working oil circuit respectively under the control of the control valve.

[0009] Furthermore, two ends of the regeneration oil passage are respectively connected to the second working oil passage and the first working oil passage.

[0010] Furthermore, the two hydraulic pumps are respectively hydraulic pump IIP1 and hydraulic pump IIP2. The hydraulic pump IIP1 supplies oil to cavity I and cavity II respectively under the control of control valve I. The control valve I includes a pressure oil port p1, an oil return port t1, a regeneration cut-off oil port c and two working oil ports a1 and b1. The pressure oil port p1 is connected to the pump outlet of the hydraulic pump IIP1, the oil return port t1 is connected to the oil return tank T, the two working oil ports a1 and b1 are respectively connected to the first working oil circuit and the second working oil circuit, and the regeneration cut-off oil port c is connected to the regeneration cut-off oil circuit.

[0011] Furthermore, the hydraulic pump IIP2 is connected to the first working oil circuit and the second working oil circuit respectively under the control of the control valve II. The control valve II includes a pressure oil port p2, an oil return port t2 and two working oil ports a2 and b2. The pressure oil port p2 is connected to the pump outlet of the hydraulic pump IIP2, the oil return port t2 is connected to the oil return tank T, and the two working oil ports a2 and b2 are connected to the first working oil circuit and the second working oil circuit respectively.

[0012] Furthermore, the control valve I and the control valve II both have a middle position and two working positions. When the control valve I and the control valve II are both in the first working position, the two hydraulic pumps merge to supply oil to cavity I, and the working oil leaked from cavity II is regenerated to cavity I through the regeneration oil circuit and / or flows through control valve I to the regeneration cut-off oil circuit and then transported to other destinations; when the two control valves are both in the second working position, the two hydraulic pumps merge to supply oil to cavity II, and the hydraulic oil leaked from cavity I can return through the two control valves.

[0013] By setting control valve I, control valve II and two working oil circuits, the two hydraulic pumps can be combined to supply oil to cavity II or cavity I. The hydraulic oil leaked from cavity I can directly return to the oil return tank through the control valve, realizing back pressure-free oil return and reducing oil consumption and pressure loss.

[0014] Furthermore, the control valve I is replaced by a control valve III, which includes a pressure oil port p3, a return oil port t3 and two working oil ports a3, b3. The pressure oil port p3 is connected to the pump outlet of the hydraulic pump I P1, the return oil port t3 is connected to the return oil tank T, and the two working oil ports a3, b3 are connected to the first working oil circuit and the second working oil circuit, respectively.

[0015] Furthermore, the control valve III has a middle position and two working positions. When the control valve III and the control valve II are both in the first working position, the two hydraulic pumps merge to supply oil to cavity I, and the working oil leaked from cavity II is regenerated to cavity I through the regeneration oil circuit or transported to other destinations through the regeneration cut-off oil circuit; when the control valve III and the control valve II are both in the second working position, the two hydraulic pumps merge to supply oil to cavity II, and the hydraulic oil leaked from cavity I can return through the control valve III and the control valve II.

[0016] Furthermore, the regeneration cut-off oil circuit is communicated with the second working oil circuit.

[0017] Based on the above technical solution, the technical effects that can be achieved by the present invention are:

[0018] 1. The hydraulic system of the working device of the present invention is provided with a regeneration oil circuit and a regeneration cut-off oil circuit, a regeneration valve is provided on the regeneration oil circuit, and a regeneration cut-off valve is provided on the regeneration cut-off oil circuit. The working oil leaked from cavity II flows to cavity I through the regeneration oil circuit to achieve regeneration and utilization, and the regeneration valve controls the working condition of the regeneration oil circuit; when cavity I does not need regeneration oil, the regeneration oil can be delivered to other destinations through the regeneration cut-off oil circuit. Compared with the prior art, the regeneration valve and the regeneration cut-off valve are separately provided and control the corresponding oil circuits, and do not need to be integrated on the control valve of the hydraulic pump, which simplifies the regeneration and regeneration cut-off control and reduces the pressure; the regeneration cut-off valve adopts a sliding valve control, and adopts hydraulic control or electric control or other methods to drive the valve core movement to control the regeneration flow and the return oil flow, so as to achieve precise control of the regeneration amount and the return oil amount. Improve the responsiveness and controllability of regeneration. At the same time, the independent control of regeneration simplifies the regeneration oil circuit and reduces fuel consumption;

[0019] 2. The hydraulic system of the working device of the present invention reasonably arranges the oil circuit, which can realize the confluence of two hydraulic pumps to supply oil to cavity II and cavity I of the actuator, and the response is fast; when the two hydraulic pumps converge to supply oil to cavity I, under the action of potential energy, the working oil leaked from cavity II can be regenerated to cavity I as regenerated oil, thereby realizing the confluence of the two hydraulic pumps and the regenerated oil; when regeneration confluence is not required, the working oil leaked from cavity II can be directly transported to other destinations through the regeneration cut-off oil circuit or transported to other destinations through the regeneration cut-off oil circuit after passing through control valve I; when the two hydraulic pumps converge to supply oil to cavity II, the oil leakage from cavity I directly returns to the oil through the two control valves that control the two hydraulic pumps, thereby realizing back pressure-free oil return and reducing oil consumption and pressure loss. In addition, the regeneration cut-off valve can be set to a valve that can be adjusted to any opening degree. In this way, during the regeneration confluence process, part of the regeneration oil can be returned through the regeneration cut-off oil circuit by controlling the opening degree of the regeneration cut-off valve, thereby controlling the oil flux of the regeneration oil regenerated to the cavity I. The above adjustment process can control the oil flux of the regeneration oil regenerated to the cavity I only by adjusting the oil flux of the regeneration cut-off oil circuit, and the adjustment process is simple and controllable.

[0020] 3. The hydraulic system of the working device of the present invention can realize the functions of combined oil supply, regeneration, regeneration cut-off and main valve core oil return while using fewer hydraulic valves, and can realize independent and precise control of regeneration and regeneration cut-off. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic diagram of a hydraulic system according to a first embodiment of the present invention;

[0022] Figure 2 It is a diagram of the oil path when the hydraulic system of the first embodiment regenerates and merges to supply oil to the cavity I;

[0023] Figure 3 It is a diagram of the oil path when the hydraulic system of the first embodiment regenerates and cuts off the oil supply to the cavity I;

[0024] Figure 4 It is a diagram of the oil path when the hydraulic system of the first embodiment merges to supply oil to the cavity II;

[0025] Figure 5 is a schematic diagram of a hydraulic system according to a second embodiment of the present invention;

[0026] Figure 6 It is a diagram of the oil path when the hydraulic system of the second embodiment regenerates and merges to supply oil to the cavity I;

[0027] Figure 7 It is a diagram of the oil path when the hydraulic system of the second embodiment regenerates and cuts off the oil supply to the cavity I;

[0028] Figure 8 It is a diagram of the oil path when the hydraulic system of the second embodiment merges to supply oil to the cavity II;

[0029] In the figure: 1-regeneration oil circuit; 11-regeneration valve group; 111-opening and closing valve; 112-check valve; 2-regeneration cut-off oil circuit; 21-regeneration cut-off valve; 31-first pumping oil circuit; 32-second pumping oil circuit; 41-control valve I; 42-control valve II; 43-control valve III; 5-first working oil circuit; 6-second working oil circuit; 61-control valve IV; 7-actuator; 71-cavity I; 72-cavity II; the non-closed arrow indicates the direction of oil inlet; the closed arrow indicates the direction of oil leakage. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0032] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0033] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0034] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0035] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0036] Embodiment 1

[0037] like Figure 1-4 As shown, this embodiment provides a hydraulic system of a working device, including at least one hydraulic pump and an actuator 7, wherein the at least one hydraulic pump sprays working oil; the actuator works by the supply of working oil from the at least one hydraulic pump.

[0038] The actuator 7 may be a hydraulic cylinder having a cavity I71 and a cavity II72. At least one hydraulic pump supplies oil to the cavity I71 or the cavity II72 to drive the actuator 7 to work. Specifically, the cavity I71 of the actuator 7 is connected to the first working oil circuit 5, and the working oil pumped out by at least one hydraulic pump enters the cavity I71 of the actuator 7 through the first working oil circuit 5; the cavity II72 of the actuator 7 is connected to the second working oil circuit 6, and the working oil pumped out by at least one hydraulic pump enters the cavity II72 of the actuator 7 through the second working oil circuit 6. Preferably, a control valve IV61 is also provided on the second working oil circuit 6, and the control valve IV61 is used to control the working oil pumped out by the two hydraulic pumps to enter the cavity II72 or drain the oil from the cavity II72 to the regeneration oil circuit 1 and / or the regeneration cut-off oil circuit 2. Preferably, the control valve IV61 is a holding valve. By setting the control valve IV as a holding valve, when the two hydraulic pumps stop supplying oil to the actuator 7, the slide valve leakage can be avoided, the working device can be prevented from falling naturally, and the working device can be kept in place.

[0039] In this embodiment, there are two hydraulic pumps, namely hydraulic pump IIP1 and hydraulic pump IIP2. Hydraulic pump IIP1 supplies oil to cavity I71 and cavity II72 respectively under the control of control valve I41, and hydraulic pump IIP2 supplies oil to cavity I71 and cavity II72 respectively under the control of control valve II42. Hydraulic pump IIP1 and hydraulic pump IIP2 can merge to supply oil to cavity I71, or merge to supply oil to cavity II72.

[0040] Specifically, the pump outlet of the hydraulic pump I P1 is connected to the first pumping oil circuit 31, and the hydraulic pump I P1 is connected to the control valve I 41 through the first pumping oil circuit 31. The control valve I 41 is a three-position five-way valve, and has five oil ports on the control valve I 41, namely, the pressure oil port p1, the return oil port t1, the regeneration cut-off oil port c, the working oil port a1 and the working oil port b1. The pump outlet of the hydraulic pump I P1 is connected to the pressure oil port p1 through the first pumping oil circuit 31, the return oil port t1 is connected to the return oil tank T, the regeneration cut-off oil port c is connected to the regeneration cut-off oil circuit 2, the working oil port a1 is connected to the first working oil circuit 5, and the working oil port b1 is connected to the second working oil circuit 6.

[0041] The control valve I41 has a neutral position and two working positions. When the control valve I41 is in the neutral position, the five oil ports are not connected; when the control valve I41 is in the first working position (i.e. Figure 1When the control valve I41 is in the second working position (i.e. the right position), the pressure oil port p1 is connected to the working oil port a1, and the working oil port b1 is connected to the regeneration cut-off oil circuit 2; when the control valve I41 is in the second working position (i.e. Figure 1 When the control valve Ⅰ41 is in the first working position, the hydraulic pump IP1 can supply oil to the cavity Ⅰ71; when the control valve Ⅰ41 is in the middle position, the hydraulic pump IP1 does not supply oil to the cavity Ⅰ71 and the cavity Ⅱ72; when the control valve Ⅰ41 is in the second working position, the hydraulic pump IP1 can supply oil to the cavity Ⅱ72, and the hydraulic oil leaked 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 electric control, hydraulic control, electro-hydraulic control or other servo motors.

[0042] The pump outlet of the hydraulic pump IIP2 is connected to the second pumping oil circuit 32, and the hydraulic pump IIP2 is connected to the control valve II42 through the second pumping oil circuit 32. The control valve II42 is a three-position four-way valve, and has four oil ports on the control valve II42, namely, the pressure oil port p2, the return oil port t2, the working oil port a2 and the working oil port b2. The pump outlet of the hydraulic pump IIP2 is connected to the pressure oil port p2 through the second pumping oil circuit 32, the return oil port t2 is connected to the return oil tank T, the working oil port a2 is connected to the first working oil circuit 5, and the working oil port b2 is connected to the second working oil circuit 6.

[0043] The control valve II 42 has a neutral position and two working positions. When the control valve II 42 is in the neutral position, the four oil ports are not connected; when the control valve II 42 is in the first working position (i.e. Figure 1 When the control valve II42 is in the second working position (i.e. the left position in the middle), the pressure oil port p2 is connected to the working oil port a2, and the working oil port b2 is disconnected from the return oil port t2; when the control valve II42 is in the second working position (i.e. Figure 1 When the control valve Ⅱ42 is in the right position, the pressure oil port p2 is connected to the working oil port b2, and the working oil port a2 is connected to the return oil port t2. When the control valve Ⅱ42 is in the first working position, the hydraulic pump ⅡP2 can supply oil to the cavity Ⅰ71; when the control valve Ⅱ42 is in the middle position, the hydraulic pump ⅡP2 does not supply oil to the cavity Ⅱ72 and the cavity Ⅰ71; when the control valve Ⅱ42 is in the second working position, the hydraulic pump ⅡP2 can supply oil to the cavity Ⅱ72, and the hydraulic oil leaked from the cavity Ⅰ71 can return to the return oil tank T through the control valve Ⅱ42. The control valve Ⅱ42 can be a three-position four-way valve controlled by electric control, hydraulic control, electro-hydraulic control or other servo motors.

[0044] By controlling control valve Ⅰ41 and control valve Ⅱ42 to be located in the first working position, hydraulic pump ⅠP1 and hydraulic pump ⅡP2 can be combined to supply oil to cavity Ⅰ71 of actuator 7; by controlling control valve Ⅰ41 and control valve Ⅱ42 to be located in the second working position, hydraulic pump ⅠP1 and hydraulic pump ⅡP2 can be combined to supply oil to cavity Ⅱ72 of actuator 7. At this time, the hydraulic oil leaked from cavity Ⅰ71 can return to the return oil tank T through control valve Ⅰ41 and control valve Ⅱ42, thereby realizing back pressure-free oil return to cavity Ⅰ71.

[0045] Preferably, a first one-way valve is provided on the first pumping oil circuit 31, and the pressure oil pumped out by the hydraulic pump IIP1 can only flow unidirectionally to the pressure oil port p1 through the first pumping oil circuit 31; a second one-way valve is provided on the second pumping oil circuit 32, and the pressure oil pumped out by the hydraulic pump IIP2 can only flow unidirectionally to the pressure oil port p2 through the second pumping oil circuit 32.

[0046] The hydraulic system of this embodiment also includes a regeneration oil circuit 1, which is used to send the return oil as the regeneration oil to the cavity I71 of the actuator 7. The return oil is the working oil leaked from the cavity II72 of the actuator 7. A regeneration valve group 11 is provided on the regeneration oil circuit 1, and the regeneration valve group 11 is used to control the flow direction and on-off of the regeneration oil on the regeneration oil circuit 1. Specifically, the two ends of the regeneration oil circuit 1 are respectively connected with the first working oil circuit 5 and the second working oil circuit 6. The regeneration valve group 11 includes an on-off valve 111 and a one-way valve 112. The on-off valve 111 can be a two-position two-way valve, which is used to control the on-off of the regeneration oil circuit 1. The one-way valve 112 controls the direction of the regeneration oil circuit 1. The hydraulic oil on the second working oil circuit 6 can flow to the first working oil circuit 5 through the one-way valve 112, but the hydraulic oil on the first working oil circuit 5 cannot flow to the second working oil circuit 6 through the regeneration oil circuit 1. Preferably, the on-off valve 111 and the one-way valve 112 are arranged in series, and the on-off valve 111 is located upstream of the one-way valve 112. In addition, the on-off valve 111 and the one-way valve 112 can also be integrated, and the one-way valve 112 is integrated on the valve core of the on-off valve 111.

[0047] The hydraulic system of this embodiment further includes a regeneration cut-off oil circuit 2, which delivers the regeneration oil to other destinations. Specifically, the regeneration cut-off oil circuit 2 is connected to the regeneration cut-off oil port c of the control valve I 41. When it is necessary to cut off the regeneration or adjust the amount of the regeneration oil, at least part of the regeneration oil leaked from the cavity II 72 can flow to the regeneration cut-off oil circuit 2 through the control valve I 41 and be delivered to other destinations.

[0048] Furthermore, a regeneration cut-off valve 21 is provided on the regeneration cut-off oil circuit 2, and the regeneration cut-off valve 21 can control the on and off of the regeneration cut-off oil circuit 2. Preferably, the regeneration cut-off valve 21 is a two-position two-way valve. Further preferably, the regeneration cut-off valve 21 is a valve that can be adjusted to any opening. When it is necessary to cut off the regeneration, the regeneration oil circuit 1 can be disconnected, and the regeneration cut-off oil circuit 2 can be connected. The regeneration oil leaked from the cavity II 72 can flow to the regeneration cut-off oil circuit 2 through the control valve I 41 and be sent to other destinations; when it is necessary to adjust the amount of regeneration oil, the regeneration oil circuit 1 can be connected, and the oil flux of the regeneration oil circuit 1 can be adjusted by adjusting the opening of the regeneration cut-off valve 21 to adjust the oil flux of the regeneration oil through the regeneration cut-off oil circuit 2. Among them, other destinations can be selected but not limited to the return oil tank T.

[0049] Preferably, the on-off valve 111 and the control valve IV61 in this embodiment can be electrically controlled, hydraulically controlled, electro-hydraulic controlled or other servo motor controlled hydraulically controlled valves.

[0050] Preferably, the actuator 7 in this embodiment is a hydraulic pump, the cavity I 71 is a rodless cavity, and the cavity II 72 is a rod cavity. In addition, the actuator 7 can be reversely set, with the cavity I 71 being a rod cavity and the cavity II 72 being a rodless cavity, which can only drive the working device to retract and swing outward.

[0051] The hydraulic system of the working device of this embodiment can be a dipper arm of an excavator. The hydraulic system of this embodiment can be used to control the operation of the dipper arm of the excavator. Based on the above structure, taking the operation of driving the dipper arm of the excavator as an example, the working principle of the hydraulic system of this embodiment is as follows:

[0052] In the initial state, the control valve I 41 and the control valve II 42 are both in the middle position, and the two hydraulic pumps do not supply oil to the actuator 7;

[0053] like Figure 2 As shown, in the early stage of the arm retraction, when the excavator has not yet performed the excavation work, the control valve I41 and the control valve II42 are both in the first working position, and the hydraulic pump IIP1 and the hydraulic pump IIIP2 merge into the cavity I71 through the first working oil circuit 5. At the same time, the regenerated oil leaked from the cavity II72 flows to the first working oil circuit 5 through the regeneration oil circuit 1, and the regenerated oil merges with the pumped oil of the two hydraulic pumps to supply oil to the cavity I71. In this stage, the regeneration oil circuit 1 is connected, the regeneration cut-off oil circuit 2 is disconnected, and the regeneration oil flows to the first working oil circuit 5 and merges with the pumped oil to supply oil to the cavity I71; in this process, the oil flux of the regenerated oil regenerated to the cavity I71 can also be controlled by adjusting the opening of the regeneration cut-off valve 21;

[0054] like Figure 3As shown, in the later stage of the arm retraction, that is, when the arm is retracted to be vertical to the ground, the control valve I41 and the control valve II42 are both in the first working position, and the hydraulic pump IIP1 and the hydraulic pump IIP2 merge into the cavity I through the first working oil circuit 5; at the same time, the regeneration oil circuit 1 is disconnected, and the regeneration cut-off oil circuit 2 is connected, and the regeneration oil leaked from the cavity II72 flows through the control valve I41 to the regeneration cut-off oil circuit 2 and is transported to other destinations. Regeneration cut-off reduces the digging pressure loss of the arm.

[0055] like Figure 4 As shown, during the outward swing of the boom, control valve Ⅰ41 and control valve Ⅱ42 are both in the second working position, and the hydraulic pump ⅠP1 and hydraulic pump ⅡP2 merge into cavity Ⅱ72 through the second working oil circuit 6, and cavity Ⅱ72 fills with oil; at the same time, the hydraulic oil leaked from cavity Ⅰ71 returns to the oil return tank T through control valve Ⅰ41 and control valve Ⅱ42.

[0056] Embodiment 2

[0057] like Figure 5-8 As shown, this embodiment is basically the same as the first embodiment, and the only difference is that, in this embodiment, the control valve I 41 is replaced by a control valve III 43, and the position of the regeneration cut-off oil circuit 2 is different from that in the first embodiment.

[0058] Specifically, the control valve III43 is a three-position four-way valve, and has four oil ports, namely the pressure oil port p3, the return oil port t3, the working oil port a3 and the working oil port b3. The pump outlet of the hydraulic pump IP1 is connected to the pressure oil port p3 through the first pumping oil circuit 31, the return oil port t3 is connected to the return oil tank T, the working oil port a3 is connected to the first working oil circuit 5, and the working oil port b3 is connected to the second working oil circuit 6.

[0059] The control valve III43 has a neutral position and two working positions. When the control valve III43 is in the neutral position, the four oil ports are not connected; when the control valve III43 is in the first working position (i.e. Figure 5 When the control valve III43 is in the second working position (i.e. the right position), the pressure oil port p1 is connected to the working oil port a3, and the working oil port b3 is disconnected from the return oil port t3; Figure 5 When the control valve III43 is in the left position, the pressure oil port p1 is connected to the working oil port b3, and the working oil port a3 is connected to the return oil port t3. When the control valve III43 is in the first working position, the hydraulic pump I P1 can supply oil to the cavity I 71; when the control valve III43 is in the middle position, the hydraulic pump I P1 does not supply oil to the cavity II 72 and the cavity I 71; when the control valve III43 is in the second working position, the hydraulic pump I P1 can supply oil to the cavity II 72, and the hydraulic oil leaked from the cavity I 71 can return to the return oil tank T through the control valve III43. Preferably, the control valve III43 can be a three-position four-way valve controlled by electric control, hydraulic control, electro-hydraulic control or other servo motors.

[0060] By controlling the control valve III43 and the control valve II42 to be both in the first working position, the hydraulic pump IIP1 and the hydraulic pump IIP2 can be combined to supply oil to the cavity I71 of the actuator 7; by controlling the control valve III43 and the control valve II42 to be both in the second working position, the hydraulic pump IIP1 and the hydraulic pump IIP2 can be combined to supply oil to the cavity II72 of the actuator 7. At this time, the hydraulic oil leaked from the cavity I71 can return to the return oil tank T through the control valve III43 and the control valve II42, thereby realizing the back pressure-free oil return of the cavity I71.

[0061] The regeneration cut-off oil circuit 2 is connected to the second working oil circuit 6. The leakage oil of the cavity II 72 can flow to the regeneration cut-off oil circuit 2 through the second working oil circuit 6. In addition, when the two hydraulic pumps merge to supply oil to the cavity II 72, the oil flux supplied to the cavity II 72 can also be controlled through the regeneration cut-off oil circuit 2.

[0062] Based on the above structure, when the hydraulic system of this embodiment is used for an excavator boom, its working principle is as follows:

[0063] In the initial state, the control valve III 43 and the control valve II 42 are both in the middle position, and the two hydraulic pumps do not supply oil to the actuator 7;

[0064] like Figure 6 As shown, in the early stage of the arm retraction, when the excavator has not yet performed the excavation work, the control valve III43 and the control valve II42 are both in the first working position, and the hydraulic pump IIP1 and the hydraulic pump IIP2 merge into the cavity I71 through the first working oil circuit 5. At the same time, the regenerated oil leaked from the cavity II72 flows to the first working oil circuit 5 through the regeneration oil circuit 1, and the regenerated oil merges with the pumped oil of the two hydraulic pumps to supply oil to the cavity I71. In this stage, the regeneration oil circuit 1 is connected, the regeneration cut-off oil circuit 2 is disconnected, and the regeneration oil flows to the first working oil circuit 5 and merges with the pumped oil to supply oil to the cavity I; in this process, the oil flux of the regeneration oil regenerated to the cavity I71 can also be controlled by adjusting the opening of the regeneration cut-off valve 21;

[0065] like Figure 7 As shown, in the later stage of the arm retraction, that is, when the arm is retracted to be vertical to the ground, the control valve III 43 and the control valve II 42 are both in the first working position, and the hydraulic pump IIP1 and the hydraulic pump IIP2 merge into the cavity I through the first working oil circuit 5; at the same time, the regeneration oil circuit 1 is disconnected, and the regeneration cut-off oil circuit 2 is connected, and the regeneration oil leaked from the cavity II 72 flows to the regeneration cut-off oil circuit 2 through the second working oil circuit 6 and is transported to other destinations. Regeneration cut-off reduces the digging pressure loss of the arm.

[0066] like Figure 8As shown, during the outward swing of the boom, control valve Ⅰ41 and control valve Ⅱ42 are both in the second working position, and the hydraulic pump ⅠP1 and hydraulic pump ⅡP2 merge into cavity Ⅱ72 through the second working oil circuit 6, and cavity Ⅱ72 fills with oil; at the same time, the hydraulic oil leaked from cavity Ⅰ71 returns to the oil return tank T through control valve Ⅰ41 and control valve Ⅱ42.

[0067] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A hydraulic system of a working device, comprising: at least one hydraulic pump, the at least one hydraulic pump spraying working oil; an actuator (7), the actuator being operated by supply of working oil from the at least one hydraulic pump; It is characterized in that It also includes a regeneration oil circuit (1), the regeneration oil circuit (1) is used to send return oil as regeneration oil to the negative pressure cavity of the actuator (7), the return oil is the working oil leaked from the actuator (7), the regeneration oil circuit (1) is provided with a regeneration valve group (11), the regeneration valve group (11) controls the on-off and flow direction of the regeneration oil circuit (1); A regeneration cut-off oil circuit (2), wherein the regeneration cut-off oil circuit (2) delivers the regenerated oil to another destination, and a regeneration cut-off valve (21) is provided on the regeneration cut-off oil circuit (2); There are two hydraulic pumps, and the pump outlets of the two hydraulic pumps are respectively provided with control valves. Under the control of the control valves, the two hydraulic pumps can merge to supply oil to the two cavities of the actuator (7) respectively; The two cavities of the actuator are cavity I (71) and cavity II (72), respectively; cavity I (71) is connected to a first working oil circuit (5), and cavity II (72) is connected to a second working oil circuit (6); each of the hydraulic pumps is connected to the first working oil circuit (5) and the second working oil circuit (6) respectively under the control of a control valve; Both ends of the regeneration oil circuit (1) are respectively connected to the second working oil circuit (6) and the first working oil circuit (5); The two hydraulic pumps are hydraulic pump IIP1 and hydraulic pump IIP2. The hydraulic pump IIP1 supplies oil to chamber I (71) and chamber II (72) respectively under the control of control valve I (41). The control valve I (41) includes a pressure oil port p1, a return oil port t1, a regeneration cut-off oil port c and two working oil ports a1 and b1. The pressure oil port p1 is connected to the pump outlet of the hydraulic pump IIP1, the return oil port t1 is connected to the return oil tank T, the two working oil ports a1 and b1 are connected to the first working oil circuit (5) and the second working oil circuit (6), respectively, and the regeneration cut-off oil port c is connected to the regeneration cut-off oil circuit (2).

2. A hydraulic system for a working device according to claim 1, characterized in that: The hydraulic pump IIP2 is connected to the first working oil circuit (5) and the second working oil circuit (6) respectively under the control of the control valve II (42). The control valve II (42) includes a pressure oil port p2, a return oil port t2 and two working oil ports a2 and b2. The pressure oil port p2 is connected to the pump outlet of the hydraulic pump IIP2, the return oil port t2 is connected to the return oil tank T, and the two working oil ports a2 and b2 are connected to the first working oil circuit (5) and the second working oil circuit (6) respectively.

3. A hydraulic system for a working device according to claim 2, characterized in that: The control valve I (41) and the control valve II (42) both have a neutral position and two working positions. When the control valve I (41) and the control valve II (42) are both in the first working position, the two hydraulic pumps merge to supply oil to the cavity I (71), and the working oil leaked from the cavity II is regenerated to the cavity I (71) through the regeneration oil circuit (1) and / or flows through the control valve I (41) to the regeneration cut-off oil circuit (2) and then transported to other destinations; when the two control valves are both in the second working position, the two hydraulic pumps merge to supply oil to the cavity II (72), and the hydraulic oil leaked from the cavity I (71) can be returned through the two control valves.

4. A hydraulic system for a working device according to any one of claims 1 to 3, characterized in that: The control valve I (41) is replaced by a control valve III (43), and the control valve III (43) includes a pressure oil port p3, a return oil port t3 and two working oil ports a3, b3. The pressure oil port p3 is connected to the pump outlet of the hydraulic pump I P1, the return oil port t3 is connected to the return oil tank T, and the two working oil ports a3, b3 are connected to the first working oil circuit (5) and the second working oil circuit (6), respectively.

5. A hydraulic system for a working device according to claim 4, characterized in that: 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 in the first working position, the two hydraulic pumps merge to supply oil to the cavity I (71), and the working oil leaked from the cavity II (72) is regenerated to the cavity I (71) via the regeneration oil circuit (1) or is transported to other destinations via the regeneration cut-off oil circuit (2); when the control valve III (43) and the control valve II (42) are both located in the second working position, the two hydraulic pumps merge to supply oil to the cavity II (72), and the hydraulic oil leaked from the cavity I (71) can be returned via the control valve III (43) and the control valve II (42).

6. A hydraulic system for a working device according to claim 4, characterized in that: The regeneration cut-off oil circuit (2) is in communication with the second working oil circuit (6).

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