CN113482089B - Flow regeneration valve group, hydraulic system and excavator - Google Patents

Abstract

The invention relates to a flow regeneration valve group, a hydraulic system and an excavator. The flow regeneration valve group includes: a main oil inlet; an oil return port; a first working oil port; a second working oil port; a back pressure valve; a first direction changing valve; and a second directional valve; the back pressure valve is configured to be closed when the pressure of the hydraulic oil introduced from the second working oil port by the first direction valve is smaller than a first opening pressure of the back pressure valve, and at this time, the second direction valve is configured to introduce the hydraulic oil of the second working oil port to the flow regeneration valve, so that the flow regeneration valve is opened to introduce the hydraulic oil of the second working oil port to the first working oil port. The first reversing valve, the second reversing valve, the backpressure valve and the flow regeneration valve are independent of each other, the backpressure valve can adjust backpressure to open the flow regeneration valve, the flow regeneration valve can directly achieve flow regeneration, the flow surface is large, flow regeneration efficiency is high, and the backpressure valve has an oil return backpressure independent continuous adjusting function.

Description

Flow regeneration valve group, hydraulic system and excavator

Technical Field

The invention relates to the field of engineering machinery, in particular to a flow regeneration valve group, a hydraulic system and an excavator.

Background

When a large excavator performs no-load single action and composite action, the bucket rod descends too fast due to the influence of self gravity to cause that the oil return speed of a rod cavity is higher than the oil supply speed of a rodless cavity, so that the rodless cavity generates an air suction phenomenon.

In some related technologies, aiming at the problem of high-pressure large-flow large-scale excavator bucket rod flow regeneration, a valve core internal flow regeneration mode is adopted, a one-way valve, a spring control assembly, a sealing plug and other structures are arranged in the valve core, the valve core moves axially in a valve body and is communicated with an oil duct connected with a rodless cavity of a bucket rod oil cylinder through small holes arranged on the valve core along the circumference, one end of the one-way valve arranged in the valve core is communicated with the oil duct connected with the rodless cavity of the bucket rod oil cylinder, and the pressure difference between the rodless cavity and the rodless cavity under the working condition of load in the bucket rod is utilized to open the one-way valve arranged in the valve core, so that redundant flow of the rodless cavity is supplemented to the rodless cavity through the one-way valve, and flow regeneration is realized.

The bucket rod linkage flow regeneration method in the related art has the following disadvantages:

1) The flow regeneration efficiency is low, most of the flow of the rod cavity is directly returned, and the flow is wasted;

2) The structural form of the valve core built-in regeneration check valve increases the complexity of the valve core, improves the processing difficulty and increases the manufacturing cost;

3) The hollow valve core needs torque when the built-in plug is installed, and the valve core is easy to expand and deform to cause valve clamping.

Disclosure of Invention

Some embodiments of the present invention provide a flow regeneration valve set, a hydraulic system, and an excavator, which are used to alleviate the problem of low flow regeneration efficiency.

In one aspect of the present invention, there is provided a flow regeneration valve block comprising:

a main oil inlet;

an oil return port;

a first working oil port;

a second working oil port;

a back pressure valve with adjustable opening pressure;

the flow regeneration valve is connected to the first working oil port;

the first reversing valve comprises a first station and is configured to guide the hydraulic oil of the main oil inlet to the first working oil port and guide the hydraulic oil of the second working oil port to the back pressure valve in the first station; and

the second reversing valve comprises a first station and is configured to guide the hydraulic oil of the main oil inlet to the first working oil port and guide the hydraulic oil of the second working oil port to the flow regeneration valve in the first station;

the back pressure valve is configured to be closed when the pressure of the hydraulic oil introduced from the second working oil port by the first direction valve is smaller than a first opening pressure of the back pressure valve, and at this time, the second direction valve is configured to introduce the hydraulic oil of the second working oil port to the flow regeneration valve, so that the flow regeneration valve is opened to introduce the hydraulic oil of the second working oil port to the first working oil port.

In some embodiments, the back pressure valve is configured to be fully opened to guide the hydraulic oil of the second working port to the oil return port when the pressure of the hydraulic oil introduced from the second working port by the first direction changing valve is greater than a second opening pressure of the back pressure valve, so that the flow regeneration valve is closed; wherein the second cracking pressure is greater than the first cracking pressure.

In some embodiments, the back pressure valve is configured to partially open when the pressure of the hydraulic oil introduced from the second working port by the first direction valve is greater than the first opening pressure and less than the second opening pressure to guide a part of the hydraulic oil of the second working port to the oil return port, and at this time, the second direction valve is configured to guide another part of the hydraulic oil of the second working port to the flow regeneration valve to open the flow regeneration valve to guide another part of the hydraulic oil of the second working port to the first working port.

In some embodiments, the flow regeneration valve comprises a check valve, an oil inlet of the check valve is connected to the second reversing valve, and an oil outlet of the check valve is connected to the first working oil port.

In some embodiments, the flow regeneration valve set further includes a throttle valve, the second directional valve includes a first oil port, a second oil port, a third oil port and a fourth oil port, the first oil port is connected to the main oil inlet, the second oil port is connected to the second working oil port, the throttle valve is disposed at the second oil port, the third oil port and the fourth oil port are connected to the first working oil port, the flow regeneration valve is disposed at the oil path between the fourth oil port and the first working oil port, when the second directional valve is at the first station, the first oil port is communicated with the third oil port, and the second oil port is communicated with the fourth oil port.

In some embodiments, the back pressure valve comprises a first port connected to the oil return port, a second port connected to the first directional valve, and a control port; the control end is configured to selectively control the first oil port to be communicated with or disconnected from the second oil port and control the communication area of the first oil port and the second oil port.

In some embodiments, the backpressure valve is a spool-type backpressure valve.

In some embodiments, the flow regeneration valve assembly further comprises:

the first one-way valve is arranged on an oil path between the main oil inlet and the first reversing valve, the oil inlet of the first one-way valve is connected to the main oil inlet, and the oil outlet of the first one-way valve is connected to the first reversing valve; and/or

And the second one-way valve is arranged on an oil path between the main oil inlet and the second reversing valve, the oil inlet of the second one-way valve is connected to the main oil inlet, and the oil outlet of the second one-way valve is connected to the second reversing valve.

In some embodiments of the present invention, the,

the first reversing valve comprises a first control end, the first control end of the first reversing valve is configured to control the first reversing valve to be in a first station, and the first control end of the first reversing valve is a pilot control end; and/or the presence of a gas in the gas,

the second reversing valve comprises a first control end, the first control end of the second reversing valve is configured to control the second reversing valve to be in a first working position, and the first control end of the second reversing valve is a pilot control end.

In some embodiments, the flow regeneration valve set includes a valve body, and the main oil inlet, the oil return port, the first working oil port, the second working oil port, the back pressure valve, the flow regeneration valve, the first direction valve, and the second direction valve are all disposed in the valve body.

In some embodiments, the first direction valve includes a first valve hole disposed in the valve body, and a first valve core disposed in the first valve hole, and the second direction valve includes a second valve hole disposed in the valve body, and a second valve core disposed in the second valve hole, and a central axis of the first valve hole and a central axis of the second valve hole are parallel to each other.

In some embodiments, the back pressure valve includes a third valve bore in the valve body, a third valve spool in the third valve bore, a central axis of the third valve bore parallel to and coplanar with a central axis of the first valve bore, and a central axis of the second valve bore parallel to a plane formed by the central axis of the first valve bore and the central axis of the third valve bore.

In some embodiments, the flow regeneration valve includes a fourth valve bore disposed within the valve body, a central axis of the fourth valve bore being perpendicular to a central axis of the second valve bore and coplanar with the central axis of the first valve bore and the central axis of the second valve bore.

In some embodiments, the flow regeneration valve assembly further comprises a throttle valve including a first orifice disposed in the second valve spool.

In some embodiments, the first and second spools are both solid spools.

In one aspect of the invention, a hydraulic system is provided, which includes a hydraulic control system including an oil cylinder and the above flow regeneration valve group, a first working oil port of the flow regeneration valve group is connected to a rodless cavity of the oil cylinder, and a second working oil port of the flow regeneration valve group is connected to a rod cavity of the oil cylinder.

In some embodiments, the hydraulic system further comprises a controller configured to adjust an opening pressure of the backpressure valve.

In one aspect of the invention, an excavator is provided, which comprises an arm and the hydraulic control system, wherein a cylinder in the hydraulic control system is connected with the arm in a driving mode.

Based on the technical scheme, the invention at least has the following beneficial effects:

in some embodiments, the first reversing valve, the second reversing valve, the backpressure valve and the flow regeneration valve are mutually independent, the backpressure valve is controlled by a single oil way, is completely decoupled from other oil ways and is not influenced by other oil ways, the backpressure valve can adjust backpressure to open the flow regeneration valve, the flow regeneration valve can directly realize flow regeneration, the flow surface is large, the flow regeneration efficiency is high, the backpressure valve has the function of independently and continuously adjusting oil return backpressure, and the requirements of different oil return backpressure under different working conditions can be met.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:

fig. 1 is a schematic diagram of the hydraulic principle of a flow regeneration valve pack provided according to some embodiments of the present invention.

Fig. 2a is a schematic cross-sectional view of a valve body provided according to some embodiments of the present invention.

FIG. 2b is a schematic cross-sectional view E-E of FIG. 2 a.

FIG. 2c is a schematic cross-sectional view F-F of FIG. 2 a.

Fig. 3a is a schematic cross-sectional view of a flow regeneration valve block provided in accordance with some embodiments of the present invention.

FIG. 3b is a schematic sectional view G-G of FIG. 3 a.

Fig. 4a is a schematic diagram of a first valve spool provided in accordance with some embodiments of the present invention.

Fig. 4b is a schematic diagram of a second valve cartridge provided in accordance with some embodiments of the present invention.

Fig. 4c is a schematic view of a third valve cartridge provided according to some embodiments of the present invention.

Fig. 5 is a schematic control flow diagram of a flow regeneration valve set during an arm retraction operation according to some embodiments of the present invention.

The reference numbers in the figures are as follows:

1-a first reversing valve; 11-a first oil port; 12-a second oil port; 13-a third oil port; 14-a fourth oil port; 15-a fifth oil port; 16-a sixth oil port; 17-a seventh oil port; 18-a first control terminal; 19-a second control terminal; 101-a first valve bore; 102-a first spool; 103-a second restriction;

2-a second reversing valve; 21-a first oil port; 22-a second oil port; 23-a third oil port; 24-a fourth oil port; 25-a fifth oil port; 26-a sixth oil port; 27-a seventh oil port; 28-eighth oil port; 29-a first control terminal; 20-a second control end; 201-a second valve bore; 202-a second valve spool;

3-back pressure valve; 31-a first oil port; 32-a second oil port; 33-a control terminal; 301-third valve opening; 302-a third spool; 303-orifice; 304-a tunnel; 305-a third throttling port;

4-a flow regeneration valve; 401-fourth valve orifice;

5-a first throttle valve; 501-a first restriction;

6-a first one-way valve; 601-fifth valve opening;

7-a second one-way valve; 701-sixth valve opening;

8-a valve body;

9-oil cylinder;

p-a main oil inlet; p1-a first main oil inlet; p2-a second main oil inlet; t-oil return port; a-a first working oil port; b-a second working oil port; d1, a first pilot oil port; d2, a second pilot oil port; d3, a third pilot oil port; d4-a fourth pilot oil port; d5-a fifth pilot oil port.

It should be understood that the dimensions of the various parts shown in the drawings are not drawn to scale. Further, the same or similar reference numerals denote the same or similar components.

Detailed Description

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is in no way intended to limit the invention, its application, or uses. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. It should be noted that: the relative arrangement of parts and steps, the composition of materials, numerical expressions and numerical values set forth in these embodiments are to be construed as merely illustrative, and not as limitative, unless specifically stated otherwise.

The use of "first," "second," and the like, herein does not denote any order, quantity, or importance, but rather the terms "first," "second," and the like are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element preceding the word covers the element listed after the word, and does not exclude the possibility that other elements are also covered. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

In the present invention, when it is described that a specific device is located between a first device and a second device, there may or may not be an intervening device between the specific device and the first device or the second device. When a particular device is described as being coupled to another device, that particular device may be directly coupled to the other device without intervening devices or may be directly coupled to the other device with intervening devices.

All terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs unless specifically defined otherwise. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

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.

As shown in fig. 1, some embodiments provide a flow regeneration valve group, which includes a main oil inlet P, an oil return port T, a first working oil port a, a second working oil port B, a first directional valve 1, a second directional valve 2, a back pressure valve 3, and a flow regeneration valve 4.

Wherein the opening pressure of the back pressure valve 3 is adjustable. The back-pressure valve 3 is configured such that its opening pressure can be adjusted steplessly.

The flow regeneration valve 4 is connected to the first working port a.

The first directional control valve 1 comprises a first position. The first directional control valve 1 is configured to guide the hydraulic oil of the main oil inlet P to the first working oil port a and the hydraulic oil of the second working oil port B to the back pressure valve 3 at the first station.

The second directional control valve 2 includes a first station, and the second directional control valve 2 is configured to direct hydraulic oil from the main oil inlet P to the first working oil port a and direct hydraulic oil from the second working oil port B to the flow regeneration valve 4 in the first station.

Wherein the back pressure valve 3 is configured to be closed when the pressure of the hydraulic oil introduced from the second working port B by the first direction valve 1 is less than the first opening pressure of the back pressure valve 3, at this time, the second direction valve 2 is configured to introduce the hydraulic oil of the second working port B to the flow regeneration valve 4, at this time, the flow regeneration valve 4 is configured to be opened to introduce the hydraulic oil of the second working port B to the first working port a.

In the embodiment of the present disclosure, when the pressure of the hydraulic oil introduced from the second working oil port B by the first direction valve 1 is less than the first opening pressure of the back pressure valve 3, the back pressure valve 3 is closed to generate a back pressure, the hydraulic oil of the second working oil port B is introduced to the flow regeneration valve 4 through the second direction valve 2, the back pressure generated by closing the back pressure valve 3 is enough to open the flow regeneration valve 4, so that the flow regeneration valve 4 is opened, and the hydraulic oil of the second working oil port B is introduced to the first working oil port a through the flow regeneration valve 4, thereby realizing flow regeneration.

In the embodiment of the disclosure, the backpressure valve 3 can be independently adjusted, is controlled by a single oil way, is completely decoupled from other oil ways, and is not influenced by other oil ways, so as to adapt to the requirements of different oil return backpressure under different working conditions. The flow regeneration valve 4 is independent from the first reversing valve 1 and the second reversing valve 2, the flow area of flow regeneration is large, and the flow regeneration efficiency is high.

In some embodiments, the back pressure valve 3 is configured such that when the pressure of the hydraulic oil introduced from the second working port B by the first direction valve 1 is greater than the second opening pressure of the back pressure valve 3, the back pressure valve 3 is fully opened to introduce the hydraulic oil of the second working port B to the oil return port T, at which time the back pressure valve 3 does not generate back pressure, the flow regeneration valve 4 cannot be opened, and the flow regeneration valve 4 is closed; wherein the second cracking pressure is greater than the first cracking pressure.

When the pressure of the hydraulic oil introduced from the second working oil port B by the first directional valve 1 is greater than the second opening pressure of the back pressure valve 3, the back pressure valve 3 is fully opened, the hydraulic oil of the second working oil port B returns through the back pressure valve 3, the back pressure valve 3 does not generate back pressure, the amount of the hydraulic oil introduced to the flow regeneration valve 4 through the second directional valve 2 is small, the pressure of the hydraulic oil is insufficient to open the flow regeneration valve 4, and the flow regeneration valve 4 is closed, so that the hydraulic oil regeneration system is suitable for the working condition without flow regeneration.

In some embodiments, the back pressure valve 3 is configured such that when the pressure of the hydraulic oil introduced from the second working port B by the first direction valve 1 is greater than the first opening pressure and less than the second opening pressure, the back pressure valve 3 is partially opened to introduce a part of the hydraulic oil of the second working port B to the oil return port T; at this time, the second directional valve 2 is configured to introduce the other part of the hydraulic oil of the second working oil port B to the flow regeneration valve 4, and at this time, the flow regeneration valve 4 is configured to open to introduce the other part of the hydraulic oil of the second working oil port B to the first working oil port a, thereby implementing the partial flow regeneration.

When the pressure of the hydraulic oil introduced from the second working oil port B by the first directional valve 1 is greater than the first opening pressure and less than the second opening pressure, the back pressure valve 3 is partially opened, a part of the hydraulic oil of the second working oil port B returns through the back pressure valve 3, the other part of the hydraulic oil is introduced to the flow regeneration valve 4 through the second directional valve 2, hydraulic pressure for opening the flow regeneration valve 4 can be generated, and the flow regeneration valve 4 is opened to introduce the other part of the hydraulic oil of the second working oil port B to the first working oil port a, so that partial flow regeneration is realized. The opening pressure of the back pressure valve 3 can realize stepless regulation, and has the functions of flow regeneration and independent and continuous regulation of oil return back pressure.

Therefore, by adjusting the opening pressure of the back pressure valve 3, the hydraulic oil of the second working oil port B can completely flow to the first working oil port a, and complete flow regeneration is realized; the hydraulic oil of the second working oil port B can partially flow to the first working oil port A, so that partial flow regeneration is realized; and hydraulic oil in the second working oil port B can be completely returned, and flow regeneration is not performed, so that the hydraulic oil recovery device is suitable for different working conditions.

In some embodiments, the flow regeneration valve 4 comprises a check valve, an oil inlet of the check valve is connected to the second directional valve 2, and an oil outlet of the check valve is connected to the first working oil port a.

In some embodiments, the flow regeneration valve block further comprises a throttle valve 5, and the second directional valve 2 comprises a first port 21, a second port 22, a third port 23, and a fourth port 24.

The first port 21 is connected to the main oil inlet P. The second oil port 22 is connected to the second working oil port B, and the throttle valve 5 is disposed in the second oil port 22. The third port 23 and the fourth port 24 are connected to the first working port a. The flow regeneration valve 4 is arranged on an oil path between the fourth oil port 24 and the first working oil port a. The flow regeneration valve 4 comprises a check valve, an oil inlet of the check valve is connected to the fourth oil port 24 of the second reversing valve 2, and an oil outlet of the check valve is connected to the first working oil port a and the third oil port 23 of the second reversing valve 2.

When the second reversing valve 2 is in the first station, the first oil port 21 is communicated with the third oil port 23, and the second oil port 22 is communicated with the fourth oil port 24.

In some embodiments, the back pressure valve 3 includes a first oil port 31, a second oil port 32, and a control port 33.

The first port 31 of the back pressure valve 3 is connected to the oil return port T, and the second port 32 of the back pressure valve 3 is connected to the first direction valve 1. Further, the second port 32 of the back pressure valve 3 is connected to the second port 12 of the first direction valve 1.

The control end 33 of the back pressure valve 3 is configured to selectively control the first port 31 to be communicated with or disconnected from the second port 32 and control the communication area of the first port 31 to the second port 32.

The control port 33 of the back pressure valve 3 may control the first port 31 and the second port 32 to be opened. The control port 33 of the back pressure valve 3 may control the communication between the first port 31 and the second port 32 of the back pressure valve 3 and may control the communication area between the first port 31 and the second port 32 of the back pressure valve 3. That is, the control port 33 of the back pressure valve 3 controls the first port 31 to partially communicate with the second port 32, and the control port 33 of the back pressure valve 3 controls the first port 31 to fully communicate with the second port 32.

The control end 33 of the back pressure valve 3 comprises a spring assembly, and the control end 33 of the back pressure valve 3 is further connected to the fifth pilot port D5.

In some embodiments, the backpressure valve 3 is a slide valve type backpressure valve and is an external pilot-controlled slide valve type backpressure valve, so that independent adjustment of any backpressure value can be realized, and the single-action linearity of the excavator bucket rod and the coordination of the composite action of the excavator bucket rod and other actuators are improved.

In some embodiments, the flow regeneration valve block further comprises a first one-way valve 6. The first one-way valve 6 is arranged on an oil path between the main oil inlet P and the first reversing valve 1, the oil inlet of the first one-way valve 6 is connected to the main oil inlet P, and the oil outlet of the first one-way valve 6 is connected to the first reversing valve 1.

Further, the main oil inlet P comprises a first main oil inlet P1 and a second main oil inlet P2. An oil inlet of the first check valve 6 is connected to the first main oil inlet P1, and an oil outlet of the first check valve 6 is connected to the third oil port 13 of the first reversing valve 1.

In some embodiments, the flow regeneration valve block further comprises a second one-way valve 7. The second one-way valve 7 is arranged on an oil path between the main oil inlet P and the second reversing valve 2, an oil inlet of the second one-way valve 7 is connected to the main oil inlet P, and an oil outlet of the second one-way valve 7 is connected to the second reversing valve 2.

Further, the main oil inlet P comprises a first main oil inlet P1 and a second main oil inlet P2. An oil inlet of the second check valve 7 is connected to the second main oil inlet P2, and an oil outlet of the second check valve 7 is connected to the first oil port 21 of the second directional control valve 2.

In some embodiments, the first direction valve 1 comprises a first control end, the first control end of the first direction valve 1 is configured to control the first direction valve 1 in the first position, and the first control end of the first direction valve 1 is a pilot control end.

In some embodiments, the second direction valve 2 comprises a first control end, the first control end of the second direction valve 2 is configured to control the second direction valve 2 in the first position, and the first control end of the second direction valve 2 is a pilot control end.

In some embodiments, the first direction valve 1, the second direction valve 2 and the back pressure valve 3 are all controlled by independent pilot hydraulic oil, and can be regulated in a proportional manner, so that the independent control among different valve cores can be realized, and good controllability can be obtained.

In some embodiments, the flow regeneration valve set includes a valve body 8, wherein the main oil inlet P, the oil return port T, the first working oil port a, the second working oil port B, the back pressure valve 3, the flow regeneration valve 4, the first direction valve 1, and the second direction valve 2 are all disposed on the valve body 8.

In the related art, the flow regeneration may be divided into an out-valve regeneration, an in-valve regeneration, and a spool regeneration, except for the arrangement position where the regeneration hydraulic oil flows through the passage. The flow regeneration valve 4 and the first reversing valve 1 are relatively independent, regenerated hydraulic oil is communicated with oil return and oil inlet in a one-way mode through an oil duct arranged in the valve body 8, redundant oil return hydraulic oil is supplemented to oil inlet hydraulic oil, and valve internal flow regeneration is achieved.

In some embodiments, the valve body 8 is provided with the independent flow regeneration valve 4 and the slide valve type backpressure valve 3, so that the flow can be regenerated in the valve, and meanwhile, the oil return backpressure can be independently adjusted to adapt to the requirements of different oil return backpressure under different working conditions.

As shown in fig. 2a, 2b, 2c, 3a, and 3b, in some embodiments, the first direction valve 1 includes a first valve bore 101 disposed within the valve body 8, and a first valve spool 102 disposed within the first valve bore 101. The second direction valve 2 includes a second valve hole 201 provided in the valve body 8, and a second valve spool 202 provided in the second valve hole 201. The central axis of the first valve hole 101 and the central axis of the second valve hole 201 are parallel to each other. The first spool 102 is disposed in the same plane as the second spool 202.

In some embodiments, the back pressure valve 3 includes a third orifice 301 disposed in the valve body 8, and a third spool 302 disposed within the third orifice 301. The central axis of the third valve orifice 301 is parallel to and coplanar with the central axis of the first valve orifice 101. The central axis of the second valve hole 201 is parallel to a plane formed by the central axis of the first valve hole 101 and the central axis of the third valve hole 301. A slide valve type backpressure valve is arranged in the third valve hole 301, and the backpressure can be adjusted randomly and continuously.

In some embodiments, the flow regeneration valve 4 includes a fourth valve bore 401 disposed within the valve body 8, a central axis of the fourth valve bore 401 being perpendicular to a central axis of the second valve bore 201, and the central axis of the fourth valve bore 401, the central axis of the first valve bore 101, and the central axis of the second valve bore 201 being coplanar.

In some embodiments, the flow regeneration valve set further comprises a throttle valve 5, and the throttle valve 5 comprises a first throttle 501 provided in the second spool 202, as shown in fig. 4 b.

In some embodiments, first spool 102 and second spool 202 are both solid spools.

The flow regeneration valve 4 is provided outside the first spool 102; through set up independent flow regeneration valve 4 in valve body 8, realize regeneration in the flow valve, and realize the solid construction of first case 102, reduce the processing degree of difficulty and the manufacturing cost of first case 102.

The valve body 8 has universality, and can replace a solid-structure valve core into a hollow-structure valve core in occasions with small regenerative quantity demand as required, and the valve body 8 has a valve core switching function and improves working condition adaptability.

Some embodiments further provide a hydraulic control system, which includes the oil cylinder 9 and the above flow regeneration valve set, a first working oil port a of the flow regeneration valve set is connected to the rodless cavity of the oil cylinder 9, and a second working oil port B of the flow regeneration valve set is connected to the rod cavity of the oil cylinder 9. The flow regeneration valve group has the functions of flow regeneration in the valve and independent and continuous adjustment of return oil backpressure.

In some embodiments, the hydraulic control system further comprises a controller configured to regulate the opening pressure of the back-pressure valve 3.

The flow regeneration valve group is flexible in control mode, the exchange of the hydraulic control end cover and the integrated electric control end cover can be realized, and the working condition adaptability is improved.

Some embodiments also provide an excavator, which comprises an arm and the hydraulic control system, wherein the oil cylinder 9 in the hydraulic control system is connected with the arm in a driving mode.

In some embodiments, the flow regeneration valve group comprises an independently adjustable backpressure valve 3, and the backpressure in the hopper rod can be adjusted proportionally, so that the regeneration rate of the flow in the hopper rod is improved. Through setting up independent adjustable back pressure valve 3, can make dipper oil feed and oil return decoupling zero, realize the great aperture of first case 102 under the great oil return backpressure operating mode, reduce oil feed pressure loss, energy saving and consumption reduction. By arranging the independent and adjustable back pressure valve 3, the adjustment of back pressure values under different flows is realized, and the suction under the working condition of composite action and insufficient flow of a large-flow ultra-large excavator is avoided. Through setting up independent adjustable back pressure valve 3, have great oil return area, quick oil return when realizing the excavation improves the digging force.

The control process of the hydraulic control system for controlling the bucket rod to retract is described below with reference to fig. 5. The small cavity in fig. 5 is a rod cavity of the oil cylinder, and the large cavity is a rodless cavity of the oil cylinder. The regeneration one-way valve is one of flow regeneration valves, and the backpressure valve core is also a third valve core.

As shown in fig. 5, the arm is retracted, the pilot oil supplied from the first pilot port D1 controls the movement of the first valve body 102, and the pilot oil supplied from the third pilot port D3 controls the movement of the second valve body 202.

And judging whether the pressure of the rod cavity of the oil cylinder 9 is greater than that of the rodless cavity.

If the pressure of the rod cavity of the oil cylinder 9 is larger than that of the rodless cavity, the flow regeneration valve is opened, and the flow of the rod cavity is regenerated to the rodless cavity.

The pressure of the rodless cavity rises, and then whether the pressure of the rod cavity of the oil cylinder 9 is larger than the pressure of the rodless cavity is judged again, and the cycle is performed in sequence.

If the pressure of the rod cavity of the oil cylinder 9 is smaller than that of the rodless cavity, the flow regeneration valve is closed, and the hydraulic oil in the rod cavity returns to the oil tank.

In the process, no matter the pressure of the rod cavity of the oil cylinder 9 is greater than the pressure of the rodless cavity or the pressure of the rod cavity of the oil cylinder 9 is less than the pressure of the rodless cavity, the pressure provided by the fifth pilot oil port D5 can be controlled, the movement of the third valve element is adjusted, the opening degree of the back pressure valve 3 is further adjusted, if the opening degree of the back pressure valve 3 is increased, the oil amount flowing back from the rod cavity to the oil tank is increased, and if the opening degree of the back pressure valve is reduced, the oil amount regenerated from the rod cavity to the rodless cavity is increased.

In the excavator, in the bucket rod adduction process, in order to realize the regeneration function, the oil return back pressure of the oil cylinder must be increased so as to obtain enough pressure difference to open the flow regeneration valve and realize the communication between the rod cavity and the rodless cavity of the oil cylinder. During the excavation process, the load is gradually increased, when the pressure of a rodless cavity of the oil cylinder is greater than that of a rod cavity, the flow regeneration valve cannot be opened, the rodless cavity and the rod cavity of the oil cylinder are disconnected and cannot be regenerated, and at the moment, in order to improve the excavation force, the back pressure needs to be reduced.

When the excavator acts on the flat ground, the back pressure is increased, so that the flow is reasonably distributed to the movable arm oil cylinder and the arm oil cylinder, the nodding phenomenon caused by insufficient flow of the movable arm oil cylinder due to excessive flow flowing to the arm oil cylinder is avoided, good flat ground performance and comfortable operability are obtained, and when the excavator acts in a combined manner with a bucket and a rotation mode, the back pressure of the arm needs to be properly increased, so that the flow is reasonably distributed.

According to the flow regeneration valve group provided by the embodiment of the disclosure, the flow regeneration valve is integrated on the valve body, the regeneration oil passage is arranged, the area of the regeneration oil passage is increased, and the flow regeneration capacity is effectively improved; simultaneously, the hollow valve core is changed into a solid valve core, so that the processing difficulty of the valve core is greatly reduced, the cost is reduced, and the valve clamping risk caused by the deformation of the valve core due to assembly is avoided. Through the arrangement of the independently adjustable slide valve type backpressure valve, the backpressure can be continuously adjusted through external control according to the working condition, the flow regeneration rate is improved while the excavating force is ensured, the flexibility of backpressure adjustment during compound action is improved, the purpose of reasonable flow distribution under multiple execution mechanisms is achieved, and the problem that the large excavator is easy to suck empty during compound action is solved.

Some specific embodiments of the flow regeneration valve assembly are described in detail below with reference to fig. 1-4.

As shown in fig. 1, the flow regeneration valve block includes: the hydraulic control system comprises a first reversing valve 1, a second reversing valve 2, a back pressure valve 3, a flow regeneration valve 4, a throttle valve 5, a first check valve 6, a second check valve 7, a main oil inlet P, an oil return port T, a first working oil port A, a second working oil port B and an oil duct for connecting the valves and the oil ports. The main oil inlet P comprises a first main oil inlet P1 and a second main oil inlet P2. The first working oil ports a are connected to the rodless cavity of the oil cylinder 9, and two first working oil ports a can be provided. The second working oil port B is connected to a rod cavity of the oil cylinder 9.

The structure, the connection mode and the working principle of each valve in the flow regeneration valve group are as follows:

the first reversing valve 1 comprises a first oil port 11, a second oil port 12, a third oil port 13, a fourth oil port 14, a fifth oil port 15, a sixth oil port 16, a seventh oil port 17, a first control end 18, a second control end 19, a first station, a second station and a third station.

The first oil port 11 of the first reversing valve 1 is connected to the oil return port T, the second oil port 12 is connected to the second oil port 32 of the back pressure valve 3, the third oil port 13 is connected to the oil outlet of the first check valve 6, the oil inlet of the first check valve 6 is connected to the first main oil inlet P1, the fourth oil port 14 is connected to the first main oil inlet P1, the fifth oil port 15 is connected to the first working oil port a, the sixth oil port 16 is connected to the second working oil port B, and the seventh oil port 17 is connected to the oil return port T.

When the first reversing valve 1 is in the first station, the first oil port 11, the fourth oil port 14 and the seventh oil port 17 are closed, the second oil port 12 is communicated with the sixth oil port 16, and the third oil port 13 is communicated with the fifth oil port 15.

When the first reversing valve 1 is in the second station, the fourth oil port 14 and the seventh oil port 17 are closed, the first oil port 11 is communicated with the fifth oil port 15, and the second oil port 12 and the third oil port 13 are communicated with the sixth oil port 16.

When the first reversing valve 1 is in the third station, the first oil port 11, the second oil port 12, the third oil port 13, the fifth oil port 15 and the sixth oil port 16 are closed, and the fourth oil port 14 is communicated with the seventh oil port 17.

The first control end 18 of the first reversing valve 1 is used for controlling the first reversing valve 1 to be located at a first station, the first control end 18 of the first reversing valve 1 is connected with the first pilot oil port D1, and the first control end 18 of the first reversing valve 1 is a bucket rod inward-retracting control end. The second control end 19 of the first reversing valve 1 is used for controlling the first reversing valve 1 to be located at the second station, the second control end 19 of the first reversing valve 1 is connected with the second pilot oil port D2, and the second control end 19 of the first reversing valve 1 is a bucket rod outward swing control end.

The back pressure valve 3 includes a first port 31, a second port 32, and a control port 33. The first port 31 is connected to the oil return port T, and the second port 32 is connected to the second port 12 of the first direction valve 1.

The control port 33 of the back pressure valve 3 may selectively control the first port 31 to be communicated with or disconnected from the second port 32, and the control port 33 of the back pressure valve 3 may control the communication area of the first port 31 to the second port 32, so that the back pressure valve 3 is partially opened or fully opened.

The control end 33 of the back pressure valve 3 comprises a spring assembly and the control end 33 of the back pressure valve 3 is further connected to the fifth pilot port D5.

The second directional valve 2 includes a first oil port 21, a second oil port 22, a third oil port 23, a fourth oil port 24, a fifth oil port 25, a sixth oil port 26, a seventh oil port 27, an eighth oil port 28, a first control end 29, a second control end 20, a first station, a second station, and a third station.

The first oil port 21 of the second directional valve 2 is connected to the second main oil inlet P2. The second check valve 7 is arranged on an oil path between the first oil port 21 of the second reversing valve 2 and the second main oil inlet P2, the oil inlet of the second check valve 7 is connected to the second main oil inlet P2, and the oil outlet of the second check valve 7 is connected to the first oil port 21 of the second reversing valve 2. The second oil port 22 of the second reversing valve 2 is connected to the second working oil port B, and the throttle valve 5 is disposed at the second oil port 22. The third oil port 23 and the fourth oil port 24 of the second reversing valve 2 are both connected to the first working oil port a. The flow regeneration valve 4 is arranged on an oil path between the fourth oil port 24 and the first working oil port a. The fifth oil port 25 of the second reversing valve 2 is connected to the second main oil inlet P2. The sixth oil port 26 of the second direction valve 2 is connected to the oil return port T, and the seventh oil port 27 of the second direction valve 2 is blocked and is sealed by a structure. The eighth port 28 of the second direction valve 2 is connected to the oil return port T.

When the second reversing valve 2 is in the first station, the first oil port 21 is communicated with the third oil port 23, and the second oil port 22 is communicated with the fourth oil port 24. The fifth port 25, the sixth port 26, the seventh port 27, and the eighth port 28 are blocked.

When the second reversing valve 2 is in the second station, the first oil port 21 is communicated with the second oil port 22, the third oil port 23 is communicated with the sixth oil port 26, and the fourth oil port 24, the fifth oil port 25, the seventh oil port 27 and the eighth oil port 28 are closed.

When the second reversing valve 2 is in the third station, the fifth oil port 25 is communicated with the eighth oil port 28, and the first oil port 21, the second oil port 22, the third oil port 23, the fourth oil port 24, the sixth oil port 26 and the seventh oil port 27 are blocked.

The first control end 29 of the second reversing valve 2 is used for controlling the second reversing valve 2 to be located at the first station, the first control end 29 of the second reversing valve 2 is connected with the third pilot oil port D3, and the first control end 29 of the second reversing valve 2 is used for controlling the inward retraction of the bucket rod. The second control end 20 of the second reversing valve 2 is used for controlling the second reversing valve 2 to be located at the second station, the second control end 20 of the second reversing valve 2 is connected with the fourth pilot oil port D4, and the second control end 20 of the second reversing valve 2 is used for controlling outward swinging of the bucket rod.

The flow regeneration valve 4 comprises a one-way valve, an oil inlet of the flow regeneration valve 4 is connected to the fourth oil port 24 of the second reversing valve 2, and an oil outlet of the flow regeneration valve 4 is connected to the third oil port 23 and the first working oil port A of the second reversing valve 2.

In some embodiments, the working principle of the in-valve flow regeneration and back pressure independent regulation of the flow regeneration valve group is as follows:

when the bucket rod of the excavator is received, the pilot hydraulic oil enters the first control end 18 of the first reversing valve 1 through the first pilot oil port D1, so that the first reversing valve 1 works at the first station, and the pilot hydraulic oil enters the first control end 29 of the second reversing valve 2 through the third pilot oil port D3, so that the second reversing valve 2 works at the first station.

For the main working oil circuit: hydraulic oil enters a rodless cavity of the oil cylinder 9 through a first main oil inlet P1, the first check valve 6, a third oil port 13 and a fifth oil port 15 of the first reversing valve 1 and a first working oil port A. Hydraulic oil enters a rodless cavity of the oil cylinder 9 through a second main oil inlet P2, the second one-way valve 7, the first oil port 21 and the third oil port 23 of the second reversing valve 2 and the first working oil port A.

Hydraulic oil in a rod cavity of the oil cylinder 9 respectively reaches the sixth oil port 16 of the first directional control valve 1 and the second oil port 22 of the second directional control valve 2 through the second working oil port B.

The hydraulic oil reaching the sixth port 16 of the first directional valve 1 reaches the second port 32 of the back pressure valve 3 through the second port 12 of the first directional valve 1.

The hydraulic oil reaching the second oil port 22 of the second directional valve 2 reaches the oil inlet of the flow regeneration valve 4 through the throttle valve 5 arranged at the second oil port 22 of the second directional valve 2 and the fourth oil port 24 of the second directional valve 2.

In the above process, the hydraulic oil at the two first working oil ports a can be merged through two ways, namely, the oil passage in the valve and the pipeline outside the valve, and then enters the rodless cavity of the oil cylinder 9.

The oil cylinder 9 is connected to an arm of an excavator in a driving mode, when the arm descends due to the gravity of the arm and a bucket, the movement speed is too high, the flow of a rodless cavity of the oil cylinder 9 is insufficient, the pilot pressure of the control end 33 of the back pressure valve 3 is reduced, the back pressure valve 3 is in a small opening or zero opening state, the return oil back pressure is increased, the hydraulic oil of the rod cavity of the oil cylinder 9 almost completely reaches the second oil port 22 of the second reversing valve 2, meanwhile, the pressure of the hydraulic oil of the rod cavity of the oil cylinder 9 is increased, the pressure after throttling is carried out through the throttling valve 5 arranged at the second oil port 22 of the second reversing valve 2 is still larger than the pressure of the rodless cavity of the oil cylinder 9, the flow regeneration valve 4 is opened under the action of the pressure difference between the rod cavity and the rodless cavity of the oil cylinder 9, almost all regeneration of the hydraulic oil of the rod cavity of the oil cylinder 9 is achieved, the flow of the rodless cavity of the oil cylinder 9 is supplemented in time, and cavitation is prevented.

When the arm is retracted and in the excavating state, the pilot pressure of the control end 33 of the back pressure valve 3 is increased by adjusting, the pilot pressure overcomes the spring pressure of the control end 33 of the back pressure valve 3, so that the back pressure valve 3 is fully opened, the flow area is maximized, and at the moment, the hydraulic oil in the rod cavity of the oil cylinder 9 reaching the sixth oil port 16 of the first reversing valve 1 returns to the tank through the second oil port 12 of the first reversing valve 1, the second oil port 32 of the back pressure valve 3 and the first oil port 31.

The opening of the back pressure valve 3 reduces the back-return pressure, thereby increasing the excavation force. Meanwhile, the rod chamber hydraulic oil pressure reaching the second oil port 22 of the second directional valve 2 is also lower, while the rodless chamber pressure is higher under the working condition, the flow regeneration valve 4 is in a closed state, and the flow is not regenerated.

When the bucket rod and other actuating mechanisms perform composite action, the required flow of different actuating mechanisms is different, the action priority degree is different, the requirements on the back pressure of the bucket rod are also different, and the pilot pressure of the control end 33 of the back pressure valve 3 is independently adjusted, so that the back pressure in the bucket rod is independently controllable, and the ideal controllability of the composite action is realized.

As shown in fig. 2 to 4, a sectional view of a valve body structure of a flow regeneration valve set, an assembly view of the flow regeneration valve set, and a schematic view of a valve core provided in an embodiment of the present disclosure are shown.

Wherein, flow regeneration valves includes valve body 8. The main oil inlet P, the oil return port T, the first working oil port A, the second working oil port B, the back pressure valve 3, the flow regeneration valve 4, the first reversing valve 1, the second reversing valve 2, the first check valve 6 and the second check valve 7 are all arranged on the valve body 8.

The first direction valve 1 includes a first valve hole 101 provided in the valve body 8, and a first valve spool 102 provided in the first valve hole 101. The second direction valve 2 includes a second valve hole 201 provided in the valve body 8, and a second valve spool 202 provided in the second valve hole 201. The back pressure valve 3 includes a third orifice 301 provided in the valve body 8, and a third spool 302 provided in the third orifice 301. The flow regeneration valve 4 includes a fourth valve hole 401 provided in the valve body 8 and a spring assembly. The first check valve 6 includes a fifth valve hole 601 provided in the valve body 8 and a spring assembly. The second check valve 7 includes a sixth valve hole 701 provided in the valve body 8 and a spring assembly.

As shown in fig. 2a, fig. 2b and fig. 2c, a cross-sectional view of a valve body structure of a flow regeneration valve set provided in an embodiment of the present disclosure is shown.

As shown in fig. 2a and 2b, the flow regeneration valve block includes a valve body 8, and a first valve hole 101, a second valve hole 201, a third valve hole 301, a fourth valve hole 401, a fifth valve hole 601 and a sixth valve hole 701 are provided in the valve body 8. The valve body 8 is further provided with a first main oil inlet P1, a second main oil inlet P2, and two first working oil ports a which are respectively a first working oil port A1, a first working oil port A2, a second working oil port B and an oil return port T.

As shown in fig. 2a, in the valve body 8, along the axial direction of the first valve hole 101, a sink groove 1a, a sink groove 1b, a sink groove 1c, a sink groove 1d, a sink groove 1e, a sink groove 1f, a sink groove 1g, a sink groove 1h, a sink groove 1i, a sink groove 1j, a sink groove 1k, and a sink groove 1n are further provided in the first valve hole 101 in this order.

In the valve body 8, along the axial direction of the second valve hole 201, a sink groove 2a, a sink groove 2b, a sink groove 2c, a sink groove 2d, a sink groove 2e, a sink groove 2f, a sink groove 2g, a sink groove 2h, a sink groove 2i, a sink groove 2j, a sink groove 2k, and a sink groove 2n are further sequentially provided on the second valve hole 201.

As shown in fig. 2b, in the valve body 8, a sink groove 3a, a sink groove 3b, a sink groove 3c, and a sink groove 3d are further provided in the third valve hole 301 in this order along the axial direction of the third valve hole 301.

As shown in fig. 2a, a sink groove 4a is provided in the fourth valve hole 401 in the valve body 8.

As shown in fig. 2a, 2b, and 2c, an annular groove R1, an annular groove R2, an oil passage R3, an oil passage R4, an oil passage R5, an oil passage R6, an oil passage R7, an oil passage R8, and an oil passage R9 are further provided in the valve body 8.

As shown in fig. 2a, the annular groove R1 communicates the sink groove 1e and the sink groove 1i of the first valve hole 101.

The annular groove R2 communicates the sink groove 2e and the sink groove 2i of the second valve hole 201.

The annular groove R1 and the annular groove R2 in the valve body 8 are the same in structure and are symmetrically arranged.

The oil passage R3 communicates the fourth valve hole 401 and the sink groove 2c in the second valve hole 201.

The oil passage R4 communicates the second working oil port B, the sink groove 1d in the first valve hole 101, and the sink groove 2d in the second valve hole 201.

The oil passage R5 communicates the first working fluid port A1, the first working fluid port A2, the sink groove 1j in the first valve hole 101, and the sink groove 2j in the second valve hole 201.

As shown in fig. 2b, the oil passage R6 communicates the sink groove 3a of the third valve hole 301 with the sink groove 1a of the first valve hole 101.

The oil passage R7 communicates with the sink groove 3b of the third valve hole 301, the sink groove 1k of the first valve hole 101, and the oil return port T.

The oil passage R8 communicates the sink groove 3c in the third valve hole 301 with the sink groove 1c in the first valve hole 101.

As shown in fig. 2c, the oil passage R9 communicates the sink groove 4a of the fourth valve hole 401, the oil passage R5, and the first working port A2.

The regeneration through-flow capacity of the valve body is increased by arranging the flow regeneration valve 4 and the regeneration oil passage R9.

After the valve hole in the valve body is inserted into the valve core, the oil ports and the control ends of the valves shown in fig. 1 corresponding to the sinking grooves are as follows:

in the first direction valve 1:

the sink groove 1a corresponds to the first control end 18 of the first direction valve 1.

The sinking groove 1b corresponds to the first oil port 11 of the first reversing valve 1 at the first station.

The sink groove 1c corresponds to the second port 12 of the first direction valve 1.

The sink groove 1d corresponds to the sixth oil port 16 of the first directional valve 1.

The sinking groove 1e corresponds to the third oil port 13 of the first reversing valve 1 at the first station.

The sinking grooves 1f, 1g and 1h correspond to the communication of the fourth oil port 14 and the seventh oil port 17 of the first reversing valve 1 in the first station, the third station and the second station.

The sinking groove 1i corresponds to the third oil port 13 of the first reversing valve 1 at the second station.

The sink groove 1j corresponds to the fifth oil port 15 of the first direction valve 1.

The sinking groove 1k corresponds to the first oil port 11 of the first reversing valve 1 at the second station.

The sink groove 1n corresponds to the second control end 19 of the first direction valve 1.

In the second direction valve 2:

the sink groove 2a corresponds to the first control end 29 of the second direction valve 2.

The sinking groove 2b corresponds to the sixth oil port 26 of the second reversing valve 2 at the first station.

The sink groove 2c corresponds to the fourth port 24 of the second direction valve 2.

The sink groove 2d corresponds to the second port 22 of the second direction valve 2.

The sinking groove 2e corresponds to the first oil port 21 of the second reversing valve 2 at the first station.

The sinking grooves 2f, 2g and 2h correspond to the communication of the fifth oil port 25 and the eighth oil port 28 of the second reversing valve 2 in the first station, the third station and the second station.

The sinking groove 2i corresponds to the first oil port 21 of the second reversing valve 2 at the second station.

The sink groove 2j corresponds to the third oil port 23 of the second direction valve 2.

The sinking groove 2k corresponds to the sixth oil port 26 of the second reversing valve 2 at the second station.

The sink groove 2n corresponds to the second control end 20 of the second direction valve 2.

Back pressure valve 3:

the sink 3a corresponds to the control end 33 of the back-pressure valve 3.

The sink 3b corresponds to the first port 31 of the back pressure valve 3.

The sink 3c corresponds to the second port 32 of the back pressure valve 3.

The sink 3d corresponds to the control end 33 of the back pressure valve 3.

As shown in fig. 3a and 3b, the flow regeneration valve set is assembled.

The first valve core 102, the second valve core 202 and the third valve core 302 are respectively installed in a first valve hole 101, a second valve hole 201 and a third valve hole 301 of the valve body 8, a first main oil inlet P1 provides hydraulic oil for the first valve core 102, and a second main oil inlet P2 provides hydraulic oil for the second valve core 202; the flow rate and the flow direction of the hydraulic oil are controlled by the axial movement of the first spool 102, the second spool 202, and the third spool 302 in the valve body 8.

The second check valve 6 and the third check valve 7 are arranged in a check valve hole in the valve body 8, so that the one-way flow of the hydraulic oil is controlled, and the hydraulic oil is prevented from flowing backwards to the main oil inlet P during pressure fluctuation.

The pilot hydraulic oil acts on the end surfaces of the first valve core 102, the second valve core 202 and the third valve core 302 through the first pilot oil port D1, the second pilot oil port D2, the third pilot oil port D3, the fourth pilot oil port D4 and the fifth pilot oil port D5, so as to control the displacement of the valve core.

The regeneration flow valve 4 is installed in a regeneration one-way valve hole and used for controlling whether hydraulic oil is regenerated or not when the bucket rod acts.

When the arm of the excavator performs the retraction motion, the pilot hydraulic oil respectively acts on the left end surfaces of the first valve core 102, the second valve core 202 and the third valve core 302 through the first pilot oil port D1, the third pilot oil port D3 and the fifth pilot oil port D5, and is caused to generate corresponding rightward displacement.

The first main oil inlet P1 and the second main oil inlet P2 reach the oil passage R5 through the annular groove R1 and the annular groove R2, the first valve core 102 and the second valve core 202 respectively and are converged, and then reach the rodless cavity of the arm cylinder 9 through the two first working oil ports A1 and A2.

The hydraulic oil in the rod chamber of the oil cylinder 9 reaches the second working oil port B, and reaches the sink groove 1d of the first valve core 102 and the sink groove 2d of the second valve core 202 through the communication oil passage R4, respectively. The hydraulic oil in the sink groove 1d reaches the sink groove 1c through the second orifice 103, reaches the sink groove 3c at the third spool 302 through the oil passage R8, and reaches the oil return port T through the third orifice 305. The third orifice 305 and the second orifice 103 enable the oil return at the sink groove 1d of the first valve core 102 to reach a certain back pressure value, and the oil return back pressure value at the sink groove 1d of the first valve core 102 is equal to the back pressure value of the sink groove 2d of the second valve core 202. The hydraulic oil in the sink groove 2d of the second valve core 202 reaches the flow regeneration valve hole 401 through the first throttle opening 501 and the oil passage R3 and acts on the upper end face of the flow regeneration valve core, the hydraulic oil pressure in the oil passage R3 is smaller than the hydraulic oil pressure in the sink groove 2d of the second valve core 202, the hydraulic oil in the sink groove 4a of the flow regeneration valve hole 401 acts on the lower end face of the regeneration one-way valve core, when the hydraulic oil pressure in the oil passage R3 is larger than the hydraulic oil pressure in the sink groove 4a, the regeneration flow valve is opened under the action of pressure difference between two ends and spring force, the hydraulic oil joins with the oil passage R5 through the regeneration oil passage R9, and reaches the rodless cavity of the oil cylinder 9 through the first working oil port A2, so that flow regeneration is realized.

The third spool 302 moves axially in the valve body 8 under the pressure of the hydraulic oil supplied from the fifth pilot port D5, and is connected to the sink groove 3c of the third valve hole 301 and the oil return port T through the third orifice 305, and the magnitude of the pressure difference between the two sides of the third orifice 305 and the oil return port T is related to the opening degree of the third orifice 305 with respect to the valve body 8. The pilot pressure of the back pressure valve 3 is independently controlled from the outside, and the opening degree of the back pressure valve 3 can be independently and continuously adjusted through independent adjustment from the outside, so that the back pressure at the sinking groove 1c and the sinking groove 3c can be independently adjusted.

As shown in fig. 4a, the second orifice 103 is provided on the first valve core 102, that is, when the first direction valve 1 shown in fig. 1 is in the first position, a throttle valve is provided on the oil path where the sixth oil port 16 communicates with the second oil port 12, for adjusting the oil return back pressure.

As shown in fig. 4b, the second valve element 202 is provided with a first orifice 501 for adjusting the return flow area.

As shown in fig. 4c, a third throttling opening 305 is provided on the third spool 302 for adjusting the flow area to obtain different back pressure values, a throttling opening 303 is further provided on the third spool 302, and a duct 304 is further provided in the third spool 302, the duct 304 communicates with the closed cavity at the sink 3d of the third spool 301 and the oil return opening T, so as to ensure that the hydraulic oil in the closed cavity at the sink 3d flows in and out in time when the back pressure valve 3 is reversed.

The third orifice 305 corresponds to a throttle provided in an oil path through which the first port 31 and the second port 32 communicate with each other in the second station of the back pressure valve 3 shown in fig. 1.

The first reversing valve 1, the second reversing valve 2, the backpressure valve 3 and the flow regeneration valve 4 are mutually independent, and independent control of the return oil backpressure and the regeneration amount of the bucket rod is achieved. The second restriction 103 and the third restriction 305 together regulate the amount of back pressure and the first restriction 501 regulates the amount of regeneration.

Synthesize above-mentioned each embodiment, the flow regeneration valves that this disclosure provided improves dipper backpressure control flexibility and energy utilization through setting up first switching-over valve, second switching-over valve, backpressure valve, flow regeneration valve isotructure. The oil inlet and return control of a rodless cavity and a rod cavity of the bucket rod oil cylinder is carried out by arranging a first valve core and a second valve core; regeneration in the flow valve is realized through setting up the regeneration valve, improves regeneration through-flow capacity, simultaneously, realizes solid formula case structure, reduces case complexity and processing cost, reduces the case because of the card valve risk that the assembly warp the production. The independent control of the oil return in the bucket rod is carried out by arranging the slide valve type backpressure valve, the continuous adjustment of backpressure is realized, the action continuity under the working condition of the load of the bucket rod and the action coordination when the bucket rod is combined with other actuating mechanisms are improved, and the problems of insufficient flow and easiness in emptying of a large excavator are solved. By arranging the slide valve type backpressure valve, the decoupling of oil inlet and oil return of the first valve core and the second valve core can be realized, and a larger oil inlet area is still kept under the working condition of increasing the oil return backpressure, so that the oil inlet pressure loss is reduced, the energy is saved, and the consumption is reduced; through setting up the slide valve formula backpressure valve, can also adjust the backpressure size according to the load, with regeneration valve cooperation, improve the flow regeneration rate.

The letters "a", "B", "D", etc. indicating the oil ports in the present disclosure are only for clearly indicating the positions of the respective oil ports in the drawings, are used to distinguish the different oil ports, and have no special meaning and no limitation.

Based on the embodiments of the invention described above, the technical features of one of the embodiments can be advantageously combined with one or more other embodiments without explicit negatives.

Although some specific embodiments of the present invention have been described in detail by way of illustration, it should be understood by those skilled in the art that the above illustration is only for the purpose of illustration and is not intended to limit the scope of the invention. It will be understood by those skilled in the art that various changes may be made in the above embodiments or equivalents may be substituted for elements thereof without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims (17)

1. A flow regeneration valve block, comprising:

a main oil inlet (P);

an oil return port (T);

a first working oil port (A);

a second working oil port (B);

a back pressure valve (3) whose opening pressure is adjustable;

a flow regeneration valve (4) connected to the first working oil port (A);

the first reversing valve (1) comprises a first station, and the first reversing valve (1) is configured to guide hydraulic oil of the main oil inlet (P) to the first working oil port (A) and guide hydraulic oil of the second working oil port (B) to the back pressure valve (3) in the first station; and

a second directional control valve (2) comprising a first station, the second directional control valve (2) being configured to direct hydraulic oil of the main oil inlet (P) to the first working oil port (A) and to direct hydraulic oil of the second working oil port (B) to the flow regeneration valve (4) in the first station;

wherein the back pressure valve (3) is configured to be closed when the pressure of the hydraulic oil introduced from the second working oil port (B) by the first direction valve (1) is less than a first opening pressure of the back pressure valve (3), and at this time, the second direction valve (2) is configured to guide the hydraulic oil of the second working oil port (B) to the flow regeneration valve (4) and open the flow regeneration valve (4) to guide the hydraulic oil of the second working oil port (B) to the first working oil port (A);

the back pressure valve (3) is configured to be fully opened when the pressure of the hydraulic oil introduced from the second working oil port (B) by the first directional control valve (1) is greater than a second opening pressure of the back pressure valve (3), so as to guide the hydraulic oil of the second working oil port (B) to the oil return port (T), and further close the flow regeneration valve (4); wherein the second cracking pressure is greater than the first cracking pressure.

2. The set of flow regeneration valves according to claim 1, wherein the back pressure valve (3) is configured to partially open the back pressure valve (3) to direct a portion of the hydraulic oil of the second working port (B) to the oil return port (T) when the pressure of the hydraulic oil introduced from the second working port (B) by the first direction valve (1) is greater than the first opening pressure and less than the second opening pressure, and at this time, the second direction valve (2) is configured to direct another portion of the hydraulic oil of the second working port (B) to the flow regeneration valve (4) to open the flow regeneration valve (4) to direct another portion of the hydraulic oil of the second working port (B) to the first working port (a).

3. Flow regeneration valve group according to claim 1, characterised in that said flow regeneration valve (4) comprises a non-return valve, the oil inlet of which is connected to said second reversal valve (2) and the oil outlet of which is connected to said first working oil port (a).

4. The flow regeneration valve group according to claim 1, further comprising a throttle valve (5), wherein the second directional valve (2) comprises a first oil port (21), a second oil port (22), a third oil port (23) and a fourth oil port (24), the first oil port (21) is connected to the main oil inlet (P), the second oil port (22) is connected to the second working oil port (B), the throttle valve (5) is disposed at the second oil port (22), the third oil port (23) and the fourth oil port (24) are connected to the first working oil port (a), the flow regeneration valve (4) is disposed on an oil path between the fourth oil port (24) and the first working oil port (a), when the second directional valve (2) is in the first station, the first oil port (21) is communicated with the third oil port (23), and the second oil port (22) is communicated with the fourth oil port (24).

5. Valve group for flow regeneration according to claim 1, characterized in that the back pressure valve (3) comprises a first port (31), a second port (32) and a control end (33), the first port (31) being connected to the return port (T), the second port (32) being connected to the first reversing valve (1); the control end (33) is configured to selectively control the first oil port (31) to be communicated with or disconnected from the second oil port (32), and control the communication area of the first oil port (31) and the second oil port (32).

6. Valve group for regeneration of the flow according to claim 1, characterised in that the back-pressure valve (3) is a slide-valve type back-pressure valve.

7. The regenerative flow valve stack of claim 1, further comprising:

the first check valve (6) is arranged on an oil path between the main oil inlet (P) and the first reversing valve (1), the oil inlet of the first check valve (6) is connected to the main oil inlet (P), and the oil outlet of the first check valve (6) is connected to the first reversing valve (1); and/or

The second one-way valve (7) is arranged on an oil path between the main oil inlet (P) and the second reversing valve (2), the oil inlet of the second one-way valve (7) is connected to the main oil inlet (P), and the oil outlet of the second one-way valve (7) is connected to the second reversing valve (2).

8. The flow regeneration valve pack of claim 1,

the first reversing valve (1) comprises a first control end, the first control end of the first reversing valve (1) is configured to control the first reversing valve (1) to be in a first working position, and the first control end of the first reversing valve (1) is a pilot control end; and/or the presence of a gas in the atmosphere,

the second reversing valve (2) comprises a first control end, the first control end of the second reversing valve (2) is configured to control the second reversing valve (2) to be in a first working position, and the first control end of the second reversing valve (2) is a pilot control end.

9. The set of flow regeneration valves according to claim 1, comprising a valve body (8), wherein the main oil inlet (P), the oil return port (T), the first working oil port (a), the second working oil port (B), the back pressure valve (3), the flow regeneration valve (4), the first directional valve (1) and the second directional valve (2) are all disposed on the valve body (8).

10. The set of flow regeneration valves according to claim 9, characterized in that the first directional valve (1) comprises a first valve hole (101) provided in the valve body (8) and a first valve spool (102) provided in the first valve hole (101), and the second directional valve (2) comprises a second valve hole (201) provided in the valve body (8) and a second valve spool (202) provided in the second valve hole (201), and the central axis of the first valve hole (101) and the central axis of the second valve hole (201) are parallel to each other.

11. The set of regenerative flow valves according to claim 10, characterized in that the back pressure valve (3) comprises a third valve hole (301) provided in the valve body (8), and a third spool (302) provided in the third valve hole (301), the central axis of the third valve hole (301) being parallel and coplanar with the central axis of the first valve hole (101), the central axis of the second valve hole (201) being parallel to the plane formed by the central axis of the first valve hole (101) and the central axis of the third valve hole (301).

12. Valve group according to claim 10, characterised in that the valve (4) comprises a fourth valve hole (401) made in the valve body (8), the median axis of the fourth valve hole (401) being perpendicular to the median axis of the second valve hole (201) and coplanar with the median axis of the first valve hole (101) and with the median axis of the second valve hole (201).

13. The set of flow regeneration valves according to claim 10, further comprising a throttle valve (5), the throttle valve (5) comprising a first throttle orifice (501) provided in the second spool (202).

14. The regenerative flow valve stack of claim 10, wherein the first spool (102) and the second spool (202) are both solid spools.

15. A hydraulic control system, characterized by comprising an oil cylinder (9) and a flow regeneration valve group according to any one of claims 1 to 14, the first working port (a) of which is connected to the rodless cavity of the oil cylinder (9), and the second working port (B) of which is connected to the rodless cavity of the oil cylinder (9).

16. The hydraulic control system of claim 15, further comprising a controller configured to regulate the opening pressure of the back pressure valve (3).

17. Excavator, characterized in that it comprises an arm and a hydraulic control system according to claim 15 or 16, in which the cylinder (9) is drivingly connected to the arm.

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