Hydraulic control valve bank, hydraulic control system and operation equipment

Abstract

The utility model relates to a hydraulic control system, and discloses a hydraulic control valve bank, a hydraulic control system and operation equipment. The hydraulic control valve group comprises first oil inlet pressure compensation valves (111) which are respectively arranged on an oil path part between an oil inlet (P) and a first working oil port (A), an oil path part between the first working oil port (A) and an oil return port (T), an oil path part between the oil inlet (P) and a second working oil port (B) and an oil path part between the second working oil port (B) and the oil return port (T); by the aid of the first oil inlet pressure compensation valve (112), the second oil inlet pressure compensation valve (113) and the second oil return pressure compensation valve (114), pressure compensation can be carried out on inlet oil and return oil of different working cavities of the hydraulic execution element under different load working conditions, so that self-adaptive control on positive and negative loads is realized. And particularly, the stable action under the large-inertia and negative-load working condition can be ensured without a complicated control algorithm, and the control difficulty is effectively reduced.

Description

Technical Field

[0001] The utility model relates to a hydraulic control system, in particular to a hydraulic control valve group. In addition, the utility model also relates to a hydraulic control system and an operating device comprising the hydraulic control valve group or the hydraulic control system. Background Art

[0002] In various types of operating equipment (such as construction machinery, agricultural machinery, etc.) with multiple hydraulic actuators, such as concrete pump trucks, the actions of extending and retracting the arm, lifting and lowering are usually driven and controlled by a hydraulic control system. Taking a concrete pump truck as an example, its boom hydraulic control system usually uses a proportional multi-way valve installed on the lower part of the vehicle to control the flow of hydraulic oil to each boom cylinder to provide hydraulic driving force and control the boom movement speed. In addition, in order to prevent the mechanism from becoming unstable under a large inertia negative load, a balancing valve can also be set near the boom cylinder in the hydraulic control circuit to control the boom lowering speed.

[0003] Chinese invention patent application CN105402180A provides a boom hydraulic control system for a concrete pump truck, in which the boom valve used in the pump truck is a proportional multi-way valve installed on the lower vehicle. The proportional multi-way valve uses a single valve core structure to control each boom cylinder, and limits the pressure difference before and after the oil inlet throttle port through the pre-pressure compensation valve to keep the oil inlet flow stable. Since the proportional multi-way valve is installed on the lower vehicle, the connecting pipeline between the proportional multi-way valve and the boom cylinder is long, and the boom hydraulic control system has problems such as delayed response of the boom cylinder and large pressure loss. In addition, when in a large inertia negative load condition, the use of the boom hydraulic control system is prone to mechanism movement stall and safety accidents. Even if back pressure can be provided by setting a balance valve near the boom cylinder and the return oil flow can be commanded and controlled within a certain range, there is still a risk of uncontrolled boom descent when the load pressure exceeds the balance valve threshold.

[0004] In view of the problems of delayed response of the boom cylinder and large pressure loss caused by the use of proportional multi-way valves in the boom hydraulic control system of concrete pump trucks, the prior art proposes a distributed structure of the pump truck boom valve to eliminate the adverse effects of the long connecting pipeline between the control end and the execution end, shorten the system response time, and reduce the system energy consumption. Chinese invention patent application CN114909346A provides a concrete pump truck boom load port independent control valve group based on a distributed structure, that is, a pair of rodless cavity control valve groups and a pair of rod cavity control valve groups are installed near the hydraulic cylinder between each boom, and each valve group includes two plug-in proportional flow valves for controlling the inlet and return oil flow. At the same time, pressure compensators are respectively arranged upstream of the oil inlet proportional flow valve to improve the linearity of the oil inlet flow control. However, under the condition of large inertia negative load, the boom hydraulic control system using the above-mentioned independent control valve group needs to ensure the load drops smoothly by controlling the opening of the return oil flow control valve, and the control difficulty is high. Utility Model Content

[0005] The purpose of the utility model is to overcome the problem in the prior art that it is difficult to achieve smooth load descent under large inertia negative load conditions, and to provide a hydraulic control valve group, a hydraulic control system and an operating equipment having the same. The hydraulic control valve group, the hydraulic control system and the operating equipment can achieve adaptive control of positive and negative loads, effectively improve the load movement stability, and reduce the control difficulty.

[0006] In order to achieve the above-mentioned object, the utility model provides a hydraulic control valve group on one hand, the hydraulic control valve group has an oil inlet, an oil return port, and a first working oil port and a second working oil port respectively connected to different working chambers of a hydraulic actuator, the hydraulic control valve group comprising:

[0007] a first oil inlet pressure compensation valve, the first oil inlet pressure compensation valve being arranged in the oil path portion between the oil inlet and the first working oil port;

[0008] a first return oil pressure compensation valve, the first return oil pressure compensation valve being arranged in the oil path portion between the first working oil port and the return oil port;

[0009] A second oil inlet pressure compensation valve, which is arranged in the oil path between the oil inlet and the second working oil port; and

[0010] A second oil return pressure compensation valve is provided in the oil path between the second working oil port and the oil return port.

[0011] Preferably, the hydraulic control valve group includes:

[0012] a first oil inlet flow control valve disposed in the oil circuit between the oil inlet and the first working oil port, wherein when oil is supplied to the hydraulic actuator through the first working oil port, the first oil inlet pressure compensation valve adjusts the valve opening according to the pressure difference before and after the hydraulic oil flows through the first oil inlet flow control valve, so as to keep the pressure difference before and after the first oil inlet flow control valve constant;

[0013] a first oil return flow control valve disposed in the oil circuit portion between the first working oil port and the oil return port, wherein when the hydraulic actuator returns oil through the first working oil port, the first oil return pressure compensation valve adjusts the valve opening according to the pressure difference before and after the hydraulic oil flows through the first oil return flow control valve, so as to keep the pressure difference before and after the first oil return flow control valve constant;

[0014] a second oil inlet flow control valve disposed in the oil circuit between the oil inlet and the second working oil port, wherein when oil is supplied to the hydraulic actuator through the second working oil port, the second oil inlet pressure compensation valve adjusts the valve opening according to the pressure difference before and after the hydraulic oil flows through the second oil inlet flow control valve, so as to keep the pressure difference before and after the second oil inlet flow control valve constant; and

[0015] A second return oil flow control valve is arranged in the oil circuit portion between the second working oil port and the return oil port. When the hydraulic actuator returns oil through the second working oil port, the second return oil pressure compensation valve adjusts the valve opening according to the pressure difference change before and after the hydraulic oil flows through the second return oil flow control valve to keep the pressure difference before and after the second return oil flow control valve constant.

[0016] Preferably, the hydraulic control valve group has a main valve body, and the oil inlet, oil return port, first working oil port and second working oil port are arranged on the main valve body; at least one group of the first oil inlet pressure compensation valve and the first oil inlet flow control valve, the first return oil pressure compensation valve and the first return oil flow control valve, the second oil inlet pressure compensation valve and the second oil inlet flow control valve, and the second return oil pressure compensation valve and the second return oil flow control valve has an integrated valve core assembly, which can be slidably installed in the main valve body so that it can be controlled to adjust the flow rate of the valve core assembly.

[0017] Preferably, the valve core assembly comprises a main valve core that slides with the main valve body, a pressure compensation valve core that is slidably installed in the inner cavity of the main valve core, and a return spring that elastically abuts against one end of the pressure compensation valve core. The two ends of the pressure compensation valve core are provided with a first hydraulic control chamber and a second hydraulic control chamber, and the return spring is arranged in the second hydraulic control chamber. The part of the main valve core corresponding to the first hydraulic control chamber is formed with a valve core oil inlet and a valve core oil outlet to allow the hydraulic oil that enters the first hydraulic control chamber from the valve core oil inlet to be discharged through the valve core oil outlet; the second hydraulic control chamber is connected to the discharge end of the valve core oil outlet, so that the pressure compensation valve core can slide in the inner cavity of the main valve core and adjust the opening of the valve core oil inlet to the first hydraulic control chamber according to the pressure difference change before and after the hydraulic oil flows through the valve core oil outlet.

[0018] Preferably, a screw plug is connected to one end of the main valve core to define the second hydraulic control chamber between the screw plug and the pressure compensation valve core, and two ends of the return spring are respectively abutted against the screw plug and the pressure compensation valve core.

[0019] Preferably, a first hydraulic control chamber connecting oil port is formed in the portion of the pressure compensating valve core corresponding to the first hydraulic control chamber, and the first hydraulic control chamber is connected to the valve core oil inlet and the valve core oil outlet respectively through the first hydraulic control chamber connecting oil port; a pressure feedback connecting oil port is formed in the portion of the main valve core corresponding to the second hydraulic control chamber, and a second hydraulic control chamber connecting oil port is formed in the portion of the pressure compensating valve core corresponding to the second hydraulic control chamber, and the second hydraulic control chamber is connected to the discharge end of the valve core oil outlet through the second hydraulic control chamber connecting oil port and the pressure feedback connecting oil port in sequence.

[0020] Preferably, the first hydraulic control chamber connecting oil port includes an oil inlet connecting oil port and an oil outlet connecting oil port distributed along the sliding direction of the pressure compensating valve core, wherein, when the pressure compensating valve core slides to different positions in the inner cavity of the main valve core, the flow cross-section between the valve core oil inlet port and the oil inlet connecting oil port continuously changes between fully open and fully closed, and the flow cross-section between the valve core oil outlet port and the oil outlet connecting oil port always remains constant.

[0021] Preferably, the first oil inlet flow control valve, the first oil return flow control valve, the second oil inlet flow control valve and the second oil return flow control valve are respectively hydraulically controlled flow valves, and the hydraulic control valve group also includes an electrically-operated proportional pressure reducing valve respectively arranged in the oil circuit portion between the oil inlet and the respective hydraulic control cavities of the first oil inlet flow control valve, the first oil return flow control valve, the second oil inlet flow control valve and the second oil return flow control valve.

[0022] Preferably, the hydraulic control valve group includes:

[0023] a first overflow oil supply valve, which is arranged in parallel with the first return oil pressure compensation valve in the oil passage between the first working oil port and the return oil port, so as to be able to overflow the return oil from the first working oil port through the return oil port or supply oil to the first working oil port;

[0024] A second overflow oil-making valve is arranged in parallel with the second return oil pressure compensation valve in the oil path portion between the second working oil port and the return oil port so as to be able to overflow the return oil from the second working oil port through the return oil port or make up oil to the second working oil port.

[0025] A second aspect of the utility model provides a hydraulic control system, comprising a main oil inlet circuit, a main oil return circuit, a first working oil circuit and a second working oil circuit respectively connected to different working chambers of a hydraulic actuator, and a hydraulic control valve group that can be controlled so that the main oil inlet circuit and the main oil return circuit are selectively connected to the first working oil circuit or the second working oil circuit, respectively, and the hydraulic control valve group comprises:

[0026] a first oil inlet pressure compensating valve, which is arranged in the oil circuit portion between the main oil inlet oil circuit and the first working oil circuit, and is capable of adjusting the valve port opening by receiving pressure feedback when oil is fed from the first working oil circuit to the hydraulic actuator, so as to maintain the oil inlet flow rate;

[0027] a first return oil pressure compensating valve, which is disposed in an oil circuit portion between the first working oil circuit and the main return oil circuit and is capable of adjusting a valve port opening by receiving pressure feedback when the hydraulic actuator returns oil from the first working oil circuit, so as to maintain a return oil flow rate;

[0028] a second oil inlet pressure compensating valve, which is disposed in the oil circuit portion between the main oil inlet oil circuit and the second working oil circuit, and is capable of adjusting the valve opening by receiving pressure feedback when oil is fed from the second working oil circuit to the hydraulic actuator, so as to maintain the oil inlet flow rate; and

[0029] A second return oil pressure compensating valve is arranged in the oil circuit portion between the second working oil circuit and the main return oil circuit, and can adjust the valve opening by receiving pressure feedback when the hydraulic actuator returns oil from the second working oil circuit to maintain the return oil flow.

[0030] Preferably, the hydraulic control valve group is the hydraulic control valve group provided in the first aspect above.

[0031] Preferably, the hydraulic control system includes a variable displacement pump provided on the main oil inlet line and a plurality of hydraulic control valve groups respectively connected to the hydraulic actuators.

[0032] A third aspect of the utility model provides an operating device, which includes the above-mentioned hydraulic control valve group or hydraulic control system.

[0033] Preferably, the operating equipment is a concrete pump truck, and the plurality of hydraulic control valve groups are respectively connected to boom cylinders of the concrete pump truck.

[0034] Through the above technical scheme, the hydraulic control valve group and hydraulic control system of the utility model can perform pressure compensation for the inlet and return oil of different working chambers of the hydraulic actuator under different load conditions, so that the movement speed of the hydraulic actuator under positive load conditions is mainly determined by the inlet oil flow rate under pressure compensation of the first oil inlet pressure compensation valve or the second oil inlet pressure compensation valve, while the movement speed under negative load conditions is mainly determined by the return oil flow rate under pressure compensation of the first return oil pressure compensation valve or the second return oil pressure compensation valve, thereby realizing adaptive control of positive and negative loads, especially ensuring smooth movement under large inertia negative load conditions without the need for complex control algorithms, effectively reducing the control difficulty. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of a hydraulic control system according to a preferred embodiment of the utility model;

[0036] Figure 2 It is a principle diagram of a hydraulic control valve group according to a preferred embodiment of the utility model;

[0037] Figure 3 It is a partial cross-sectional view of a hydraulic control valve group according to a preferred embodiment of the utility model;

[0038] Figure 4 yes Figure 3 A cross-sectional view of the valve core assembly of the hydraulic control valve group;

[0039] Figure 5 is a schematic diagram of a hydraulic control valve group according to another preferred embodiment of the utility model;

[0040] Figure 6 It is a schematic diagram of a hydraulic control system of another preferred embodiment of the utility model.

[0041] Description of Reference Numerals

[0042] 1-main valve body; 2-valve core assembly; 21-main valve core; 22-pressure compensation valve core; 23-reset spring; 24-screw plug; 25-first hydraulic control chamber; 26-second hydraulic control chamber;

[0043] P1-valve body oil inlet; A1-valve body oil outlet; P21-valve core oil inlet; A21-valve core oil outlet; F21-pressure feedback oil port; P22-first hydraulic control chamber oil port; P221-inlet oil port; P222-outlet oil port; F22-second hydraulic control chamber oil port;

[0044] 100-hydraulic control valve group; 111-first oil inlet pressure compensation valve; 112-first oil return pressure compensation valve; 113-second oil inlet pressure compensation valve; 114-second oil return pressure compensation valve; 121-first oil inlet flow control valve; 122-first oil return flow control valve; 123-second oil inlet flow control valve; 124-second oil return flow control valve; 13-electric proportional pressure reducing valve; 141-first overflow oil replenishing valve; 142-second overflow oil replenishing valve; 15-fixed value pressure reducing valve;

[0045] 200-hydraulic actuator; 300-load;

[0046] P- oil inlet; T- oil return port; A- first working oil port; B- second working oil port; Y- pilot oil return port;

[0047] L P -Main oil inlet circuit; L T -Main oil return line; L A -First working oil circuit; L B - Second working oil circuit. DETAILED DESCRIPTION

[0048] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0049] In the present utility model, the terms "first", "second", etc. are only used to distinguish different technical features, and are not used to limit the importance of the technical features. If necessary, the effects that can be achieved by these technical features are basically the same.

[0050] According to the context, the hydraulic control valve group of the utility model can be used as a distributed boom valve for concrete pump trucks. Although integrating the individual valves in the hydraulic control valve group corresponding to each boom cylinder is beneficial for improving system integration and installation convenience, the hydraulic control valve group of the utility model is not limited to having a unique valve body or integrated block shared by each single valve. It can also connect the individual valves through pipelines to form a combination of valves. In addition, in order to facilitate a clear understanding of the technical solution, working principle and advantages of the utility model, the hydraulic control valve group and hydraulic control system of the utility model will be mainly illustrated below by taking the boom valve of a pump truck and the hydraulic control system of a pump truck boom as examples, but it can be understood that the hydraulic control valve group and the hydraulic control system can also be applied to other application scenarios where motion control may be performed under positive and negative load conditions, such as various types of operating equipment with one or more hydraulic actuators, such as engineering machinery, agricultural machinery, and operating robots.

[0051] Reference Figure 1 As shown, one aspect of the utility model provides a hydraulic control system, which includes a main oil inlet circuit L P , Main oil return line L T , respectively connected to the first working oil passages L of different working chambers of the hydraulic actuator 200 A And the second working oil circuit L B And can be controlled so that the main oil inlet oil path L P And the main oil return line L T Selectively connected to the first working oil passage L A Or the second working oil circuit L B The hydraulic control valve group 100. Among them, the main oil inlet oil circuit L P A hydraulic pump may be provided on the main oil return line L to pump the hydraulic oil in the hydraulic oil tank under pressure to the hydraulic actuator 200. T It can be connected to the hydraulic oil tank to collect the hydraulic oil discharged by the hydraulic actuator 200. Here, the hydraulic actuator 200 is shown as a cylinder, which can be connected to a load 300 such as a pump truck boom, so that it can be driven by the pump truck boom cylinder to achieve the arm extension and arm retraction movements. The hydraulic control valve group 100 can be controlled so that the oil inlet and return oil circuits in the hydraulic control system form different on-off states to change the telescopic movement direction of the boom cylinder. In the preferred embodiment shown in the figure, the first working oil circuit L A The rodless chamber connected to the hydraulic actuator 200 (i.e., the boom cylinder), the second working oil circuit L B The rod chamber of the boom cylinder is connected to the boom cylinder. Therefore, when the hydraulic control valve group 100 is controlled to make the main oil inlet oil path L P Connected to the first working oil passage L A , Main oil return line LT Connected to the second working oil passage L B When the main oil inlet line L P The pumped hydraulic oil will cause the piston rod of the boom cylinder to extend; when the hydraulic control valve group 100 is controlled to make the main oil inlet oil circuit L P Connected to the second working oil passage L B , Main oil return line L T Connected to the first working oil passage L A When the main oil inlet line L P The pumped hydraulic oil will cause the piston rod of the boom cylinder to retract. To this end, the valve used to control the on-off state in the hydraulic control valve group 100 can be set in various forms, such as a combination of multiple valves connected by pipelines, a multi-way reversing valve, a multi-way valve, etc.

[0052] In order to facilitate driving the load 300 in different movement directions and different load conditions of the hydraulic actuator 200 so as to make the load 300 move smoothly, the hydraulic control valve group 100 also includes a pressure compensation valve for reducing flow fluctuations in the inlet and return oil flow paths, so as to reduce or avoid the influence of load changes on the inlet oil flow supplied to the hydraulic actuator 200 and the return oil flow returned from the hydraulic actuator 200 to the hydraulic oil tank. Specifically, the hydraulic control valve group 100 includes a first inlet oil pressure compensation valve 111, a first return oil pressure compensation valve 112, a second inlet oil pressure compensation valve 113 and a second return oil pressure compensation valve 114, wherein the first inlet oil pressure compensation valve 111 is arranged in the main inlet oil path L P And the first working oil circuit L A The oil passage between the first working oil passage L A When oil is fed into the hydraulic actuator 200, the valve opening is adjusted by receiving pressure feedback to maintain the oil flow rate; the first return oil pressure compensation valve 112 is arranged in the first working oil circuit L A And the main oil return line L T The oil circuit portion between the hydraulic actuator 200 and the first working oil circuit L A When returning oil, the valve opening is adjusted by receiving pressure feedback to maintain the return oil flow rate; the second oil inlet pressure compensation valve 113 is set in the main oil inlet oil circuit L P And the second working oil circuit L B The oil passage between the two parts can be connected by the second working oil passage L B When oil is fed into the hydraulic actuator 200, the valve opening is adjusted by receiving pressure feedback to maintain the oil flow rate; the second return oil pressure compensation valve 114 is arranged in the second working oil circuit L B And the main oil return line L T The oil circuit portion between the hydraulic actuator 200 and the second working oil circuit L BWhen returning oil, the valve opening is adjusted by receiving pressure feedback to maintain the return oil flow.

[0053] Therefore, the hydraulic control system can perform pressure compensation on the inlet and return oil of different working chambers of the hydraulic actuator 200 under different load conditions, so that the movement speed of the hydraulic actuator under positive load conditions is mainly determined by the inlet oil flow rate under pressure compensation by the first oil inlet pressure compensation valve 111 or the second oil inlet pressure compensation valve 113, while the movement speed under negative load conditions is mainly determined by the return oil flow rate under pressure compensation by the first return oil pressure compensation valve 112 or the second return oil pressure compensation valve 114, thereby realizing adaptive control of positive and negative loads, especially ensuring smooth movement under large inertia negative load conditions without the need for complex control algorithms, effectively reducing the control difficulty.

[0054] For example, under positive load conditions, when the piston rod of the hydraulic actuator 200 (arm cylinder) extends, the main oil inlet circuit L P Connected to the first working oil passage L A , main oil return line L T Connected to the second working oil passage L B , the first working oil circuit L A The driving force generated is greater than or equal to the load force, and the boom cylinder overcomes the load force and moves. P Flows to the first working oil passage L A During the process, the first oil inlet pressure compensation valve 111 can receive the pressure feedback before and after the valve (such as the first oil inlet flow control valve 121 shown in the figure) used to control the on-off state in the aforementioned hydraulic control valve group 100, and adjust the valve opening accordingly, so that the pressure difference before and after the valve remains basically constant when the load changes, and the hydraulic oil flow (i.e., the oil inlet flow) passing through it is only determined by the opening of the valve itself. During this process, the control pressure difference of the second return oil pressure compensation valve 114 is less than the set pressure difference (the feedback pressure is smaller), and its valve port is fully open, thereby effectively reducing the pressure loss.

[0055] Under negative load conditions, when the piston rod of the hydraulic actuator 200 (arm cylinder) extends, the second working oil circuit L B The resistance generated is less than or equal to the load force, and the load 300 drags the boom cylinder to move. At this time, the hydraulic oil discharged from the boom cylinder is discharged from the second working oil circuit L B Flows to the main oil return line L TDuring the process, the second return oil pressure compensation valve 114 can receive pressure feedback before and after the valve (such as the second return oil flow control valve 124 shown in the figure) in the aforementioned hydraulic control valve group 100 for controlling the on and off state, and adjust the valve opening accordingly to keep the pressure difference before and after the valve basically constant when the load changes, and the hydraulic oil flow (i.e., return oil flow) passing through it is only determined by the opening of the valve itself.

[0056] Therefore, the hydraulic control system of the utility model can perform pressure compensation for the inlet and return oil of different working chambers of the hydraulic actuator under different load conditions, and can automatically adapt to positive and negative load conditions, with small pressure loss and good load impact resistance, and can ensure smooth operation under large inertia negative load conditions without the need for complex control algorithms.

[0057] Reference Figures 2 to 4 As shown, another aspect of the present invention provides a hydraulic control valve group 100, which has an oil inlet P, an oil return port T, and a first working oil port A and a second working oil port B respectively used to be connected to different working chambers of a hydraulic actuator 200. In order to facilitate driving the hydraulic actuator 200 in different movement directions and under different load conditions so as to make the load 300 move smoothly, the hydraulic control valve group 100 of the present invention includes a pressure compensation valve for reducing flow fluctuations in the oil inlet and return flow paths, so as to reduce or avoid the influence of load changes on the oil inlet flow supplied to the hydraulic actuator 200 and the oil return flow returned from the hydraulic actuator 200 to the hydraulic oil tank. Specifically, the hydraulic control valve group 100 includes a first oil inlet pressure compensation valve 111, a first oil return pressure compensation valve 112, a second oil inlet pressure compensation valve 113 and a second oil return pressure compensation valve 114, wherein the first oil inlet pressure compensation valve 111 is arranged in the oil circuit portion between the oil inlet port P and the first working oil port A, and can adjust the valve port opening by receiving pressure feedback when oil is supplied to the hydraulic actuator 200 through the first working oil port A to maintain the oil inlet flow rate; the first oil return pressure compensation valve 112 is arranged in the oil circuit portion between the first working oil port A and the oil return port T, and can adjust the valve port opening by receiving pressure feedback when oil is supplied to the hydraulic actuator 200 through the first working oil port A to maintain the oil inlet flow rate; The second oil return pressure compensation valve 114 is provided in the oil circuit between the second working oil port B and the hydraulic actuator 200, and can adjust the valve port opening by receiving pressure feedback when the hydraulic actuator 200 returns oil through the second working oil port B, so as to maintain the oil return flow rate; the second oil return pressure compensation valve 114 is provided in the oil circuit between the second working oil port B and the oil return port T, and can adjust the valve port opening by receiving pressure feedback when the hydraulic actuator 200 returns oil through the second working oil port B, so as to maintain the oil return flow rate.

[0058] Therefore, similar to the above-mentioned hydraulic control system, the hydraulic control valve group 100 can perform pressure compensation on the inlet and return oil of different working chambers of the hydraulic actuator 200 under different load conditions, so that the movement speed of the hydraulic actuator under positive load conditions is mainly determined by the inlet oil flow rate under pressure compensation of the first oil inlet pressure compensation valve 111 or the second oil inlet pressure compensation valve 113, while the movement speed under negative load conditions is mainly determined by the return oil flow rate under pressure compensation of the first return oil pressure compensation valve 112 or the second return oil pressure compensation valve 114, thereby realizing adaptive control of positive and negative loads, especially ensuring smooth movement under large inertia negative load conditions without the need for complex control algorithms, effectively reducing the control difficulty.

[0059] Due to the same principle, the hydraulic control valve group 100 of various embodiments described above and below is applicable to the hydraulic control system provided by the utility model. Therefore, the hydraulic control valve group 100 of various preferred and optional embodiments described below can be regarded as an explanation of the corresponding embodiments of the hydraulic control system.

[0060] As mentioned above, the hydraulic control valve group 100 is used to control the main oil inlet oil circuit L P And the main oil return line L T (Oil inlet P and oil return port T) and the first working oil circuit L A And the second working oil circuit L B The valve for switching the on / off state between the first working oil port A and the second working oil port B can be set in various forms, such as a combination of multiple valves connected by pipelines, a multi-way reversing valve, a multi-way valve, etc., as long as it can switch the main oil inlet line L P And the main oil return line L T (Oil inlet P and oil return port T) and the first working oil circuit L A And the second working oil circuit L B The on / off state and valve opening degree between (the first working oil port A and the second working oil port B) are sufficient.

[0061] exist Figure 1 and Figure 2In the preferred embodiment shown, the hydraulic control valve group 100 includes a first oil inlet flow control valve 121, a first oil return flow control valve 122, a second oil inlet flow control valve 123 and a second oil return flow control valve 124, wherein the first oil inlet flow control valve 121 is arranged in series with the first oil inlet pressure compensation valve 111 in the oil circuit portion between the oil inlet port P and the first working oil port A. When the hydraulic actuator 200 is supplied with oil through the first working oil port A, the first oil inlet pressure compensation valve 111 adjusts the valve port opening according to the pressure difference before and after the hydraulic oil flows through the first oil inlet flow control valve 121 to keep the pressure difference before and after the first oil inlet flow control valve 121 constant; the first oil return flow control valve 122 is arranged in series with the first oil return pressure compensation valve 112 in the oil circuit portion between the first working oil port A and the oil return port T. When the hydraulic actuator 200 returns oil through the first working oil port A, the first oil return pressure compensation valve 112 adjusts the valve port opening according to the pressure difference before and after the hydraulic oil flows through the first oil return flow control valve 12 2 before and after the pressure difference changes to adjust the valve opening, so as to keep the pressure difference before and after the first return oil pressure compensation valve 112 constant; the second oil inlet flow control valve 123 is arranged in series with the second oil inlet pressure compensation valve 113 in the oil circuit portion between the oil inlet port P and the second working oil port B. When the hydraulic actuator 200 is supplied with oil through the second working oil port B, the second oil inlet pressure compensation valve 113 adjusts the valve opening according to the pressure difference before and after the hydraulic oil flows through the second oil inlet flow control valve 123, so as to keep The pressure difference before and after the second oil inlet pressure compensation valve 113 is constant; the second return oil flow control valve 124 is arranged in series with the second return oil pressure compensation valve 114 in the oil circuit portion between the second working oil port B and the return oil port T. When the hydraulic actuator 200 returns oil through the second working oil port B, the second return oil pressure compensation valve 114 adjusts the valve opening according to the change in the pressure difference before and after the hydraulic oil flows through the second return oil flow control valve 124 to keep the pressure difference before and after the second return oil pressure compensation valve 114 constant.

[0062] Furthermore, the first oil inlet flow control valve 121, the first oil return flow control valve 122, the second oil inlet flow control valve 123 and the second oil return flow control valve 124 can be electromagnetic valves or hydraulically controlled valves to control their respective valve cores by electromagnetic force or hydraulic force. In the preferred embodiment shown in the figure, each of the flow control valves is configured as a hydraulically controlled flow valve. P Or the oil inlet P obtains the appropriate hydraulic control pressure, the hydraulic control valve group 100 of the utility model can also include a main oil inlet oil circuit L P Or a pilot control oil circuit with a pressure reducing valve between the oil inlet P and the hydraulic control chamber of each of the above-mentioned flow control valves. Specifically, Figure 1 and Figure 2As shown, a fixed-value pressure reducing valve 15 and an electric proportional pressure reducing valve 13 corresponding to each flow control valve can be provided on the pilot control oil circuit, wherein the fixed-value pressure reducing valve 15 can convert the high-pressure oil at the oil inlet P into low-pressure oil with constant pressure, and then apply pressure to the hydraulic control chamber of the flow control valve through the electric proportional pressure reducing valve 13, and the excess oil can be discharged through the pilot oil return port Y. The electric proportional pressure reducing valve 13 includes a first electric proportional pressure reducing valve 131 arranged on the oil circuit portion between the oil inlet P and the hydraulic control chamber of the first oil inlet flow control valve 121, a second electric proportional pressure reducing valve 132 arranged on the oil circuit portion between the oil inlet P and the hydraulic control chamber of the first oil return flow control valve 122, a third electric proportional pressure reducing valve 133 arranged on the oil circuit portion between the oil inlet P and the hydraulic control chamber of the second oil inlet flow control valve 123, and a fourth electric proportional pressure reducing valve 134 arranged on the oil circuit portion between the oil inlet P and the hydraulic control chamber of the second oil return flow control valve 124. These electric proportional pressure reducing valves 13 convert the pressure output by the fixed value pressure reducing valve 15 (if any) into different levels of pressure based on the current control signal, and then act on the first oil inlet flow control valve 121, the first oil return flow control valve 122, the second oil inlet flow control valve 123 and the second oil return flow control valve 124 respectively, so as to realize the control of the main oil inlet oil circuit L P And the main oil return line L T (Oil inlet P and oil return port T) and the first working oil circuit L A And the second working oil circuit L B The on-off state between (the first working oil port A and the second working oil port B) and the control of the oil inlet and return flow rates. Thus, based on the hydraulic control pressure output by each electric proportional pressure reducing valve 13, the on-off state and opening degree of the first oil inlet flow control valve 121, the first oil return flow control valve 122, the second oil inlet flow control valve 123 and the second oil return flow control valve 124 can be adjusted, and in conjunction with the corresponding first oil inlet pressure compensation valve 111, the first oil return pressure compensation valve 112, the second oil inlet pressure compensation valve 113 and the second oil return pressure compensation valve 114, the oil inlet and return flow rates of the first working oil port A and the second working oil port B can be controlled, so that the hydraulic actuator 200 and the load 300 can move smoothly under different working conditions.

[0063] It can be understood that when the system working pressure is relatively low, the first oil inlet flow control valve 121, the first oil return flow control valve 122, the second oil inlet flow control valve 123 and the second oil return flow control valve 124 can be set as solenoid valves, thereby omitting the above-mentioned electric proportional pressure reducing valves 13.

[0064] In addition, the hydraulic control valve group 100 may further include a first overflow oil replenishing valve 141 and a second overflow oil replenishing valve 142, wherein the first overflow oil replenishing valve 141 is arranged in parallel with the first return oil pressure compensation valve 112 in the oil circuit portion between the first working oil port A and the return oil port T, so as to overflow the return oil from the first working oil port A through the return oil port T or replenish oil to the first working oil port A; the second overflow oil replenishing valve 142 is arranged in parallel with the second return oil pressure compensation valve 114 in the oil circuit portion between the second working oil port B and the return oil port T, so as to overflow the return oil from the second working oil port B through the return oil port T or replenish oil to the second working oil port B. Thus, the first overflow oil replenishing valve 141 and the second overflow oil replenishing valve 142 can respectively limit the maximum working pressure of the first working oil port A and the second working oil port B, and replenish hydraulic oil when the working pressure is too low, thereby playing a safety protection role. For example, when the boom cylinder as the hydraulic actuator 200 is extended and in a negative load condition, the first overflow oil replenishment valve 141 can be opened to replenish hydraulic oil to the rodless chamber. It should be understood that although it is generally referred to as a "overflow oil replenishment valve" here, it can be two relatively independent valves (a one-way valve and a relief valve).

[0065] exist Figures 1 to 4 In the preferred embodiment shown in the figure, the first oil inlet flow control valve 121, the first oil return flow control valve 122, the second oil inlet flow control valve 123 and the second oil return flow control valve 124 are respectively shown as two parts located before and after the corresponding pressure compensation valve in the hydraulic principle diagram. This is because it adopts Figure 3 and Figure 4 The corresponding relationship and specific working principle of the combined valve core (i.e., valve core assembly 2) of the embedded structure shown will be described in detail later. Among them, corresponding to the same hydraulic actuator 200, each of the above-mentioned flow control valves in the preferred embodiment has an independent valve core assembly 2, and each is integrated with a pressure compensation valve. Therefore, the hydraulic control valve group 100 can have a main valve body 1, and the oil inlet P, the oil return port T, and the first working oil port A and the second working oil port B can be arranged on the main valve body 1. The first oil inlet pressure compensation valve 111 and the first oil inlet flow control valve 121, the first oil return pressure compensation valve 112 and the first oil return flow control valve 122, the second oil inlet pressure compensation valve 113 and the second oil inlet flow control valve 123, and the second oil return pressure compensation valve 114 and the second oil return flow control valve 124 can respectively have an integrated valve core assembly 2, which can be slidably installed in the main valve body 1 so as to be controlled to adjust the flow rate of the valve core assembly 2, that is, to have different oil inlet and return flow rates between the oil inlet port P and / or the oil return port T and the first working oil port A and / or the second working oil port B. Therefore, the valve core of the pressure compensation valve is integrated into the flow control valve through the integrated design of the valve core assembly 2, which can effectively reduce the volume of the hydraulic control module and improve the system integration.

[0066] In an alternative embodiment, the first oil inlet flow control valve 121 and the first oil return flow control valve 122, the second oil inlet flow control valve 123 and the second oil return flow control valve 124 may respectively have a common valve core or valve cores fixedly connected to each other, thereby mechanically ensuring that when one of the oil inlet port P and the oil return port T is connected to the first working oil port A, the other is cut off from the first working oil port A; the same is true for the second working oil port B.

[0067] exist Figure 5 In another preferred embodiment shown, the first oil inlet flow control valve 121, the first oil return flow control valve 122, the second oil inlet flow control valve 123 and the second oil return flow control valve 124 are shown to be located only downstream (along the oil inlet and return directions) of the first oil inlet pressure compensation valve 111, the first oil return pressure compensation valve 112, the second oil inlet pressure compensation valve 113 and the second oil return pressure compensation valve 114, respectively. This can be achieved by using other valve core forms such as multi-way valves, and arranging pressure compensation valves with independent valve cores at corresponding valve ports or oil ports. The other parts of this preferred embodiment are combined with the above Figure 1 and Figure 2 The described implementation methods are the same and will not be repeated here.

[0068] The following combination Figures 2 to 4 The valve core assembly 2 of the embedded structure used in the preferred embodiment of the utility model is described as follows:

[0069] The valve core assembly 2 includes a hollow main valve core 21, a pressure compensation valve core 22 slidably installed in the inner cavity of the main valve core 21, and a return spring 23 elastically abutting against one end of the pressure compensation valve core 22, wherein the main valve core 21 can be installed to slide with the main valve body 1, and the two ends of the pressure compensation valve core 22 are provided with a first hydraulic control cavity 25 and a second hydraulic control cavity 26. The return spring 23 and the oil pressure in the second hydraulic control cavity 26 exert the same force on the pressure compensation valve core 22.

[0070] like Figure 3 and Figure 4 As shown, the portion of the main valve core 21 corresponding to the first hydraulic control chamber 25 is formed with a valve core oil inlet P21 and a valve core oil outlet A21, so as to allow the hydraulic oil introduced into the first hydraulic control chamber 25 through the valve core oil inlet P21 to be discharged through the valve core oil outlet A21. The second hydraulic control chamber 26 is connected to the discharge end of the valve core oil outlet A21, so that the pressure compensation valve core 22 can slide in the inner cavity of the main valve core 21 according to the pressure difference before and after the hydraulic oil flows through the valve core oil outlet A21, and adjust the opening of the valve core oil inlet P21 connected to the first hydraulic control chamber 25.

[0071] For ease of understanding, Figure 2The schematic diagram schematically marks the positions of the valve core oil inlet P21, valve core oil outlet A21, first hydraulic control chamber 25 and second hydraulic control chamber 26 in the oil circuit between the oil inlet P and the first working oil port A. According to the above arrangement, the valve core assembly 2 can be driven to slide relative to the main valve body 1 by electric or hydraulic control, so that the valve body oil inlet P1 on the main valve body 1 is connected or cut off with the valve core oil inlet P21, or has different flow cross-sectional areas; at the same time, the valve body oil outlet A1 on the main valve body 1 is connected or cut off with the valve core oil outlet A21, or has different flow cross-sectional areas. When the valve core assembly 2 is used in the oil circuit between the oil inlet P and the first working oil port A, the valve body oil inlet P1 is the oil inlet P of the hydraulic control valve group 100 or is connected to the oil inlet P, and the valve body oil outlet A1 is the first working oil port A of the hydraulic control valve group 100 or is connected to the first working oil port A. When the valve core assembly 2 is used for the oil circuit portion between the first working oil port A and the return oil port T, the valve body oil inlet P1 is the first working oil port A of the hydraulic control valve group 100 or is connected to the first working oil port A, and the valve body oil outlet A1 is the return oil port T of the hydraulic control valve group 100 or is connected to the return oil port T.

[0072] Since the pressure compensation valve core 22 can slide in the inner cavity of the main valve core 21 according to the pressure difference change before and after the hydraulic oil flows through the valve core oil outlet A21, and adjust the opening of the valve core oil inlet P21 connected to the first hydraulic control cavity 25, under different load conditions, the oil inlet circuit or oil return circuit provided with the valve core assembly 2 can perform pressure compensation for the inlet and return oil of the hydraulic actuator, thereby reducing or avoiding the influence of load changes on the inlet and return oil flow rates.

[0073] When the valve core assembly 2 is not oiled, that is, the corresponding oil inlet or oil return line is cut off, under the action of the return spring 23, the valve core oil inlet port P21 is connected to the first hydraulic control chamber 25. At the same time, the valve core oil outlet port A21 is connected to the first hydraulic control chamber 25, and the discharge end of the valve core oil outlet port A21 is connected to the second hydraulic control chamber 26. At this time, the hydraulic forces acting on the first hydraulic control chamber 25 and the second hydraulic control chamber 26 of the pressure compensation valve core 22 are P and P, respectively. p A and P a A, and have the following relationship:

[0074] (P p -P a )A≤kx0

[0075] Among them, P p and P a are the oil pressures in the first hydraulic control chamber 25 and the second hydraulic control chamber 26 respectively, A is the effective area at both ends of the pressure compensation valve core 22, k is the stiffness of the return spring, and x0 is the pre-compression amount of the return spring.

[0076] When the valve core assembly 2 is oiled, that is, the corresponding oil inlet or return oil circuit is connected, the hydraulic oil enters the first hydraulic control chamber 25 through the valve core oil inlet port P21, and the pressure compensation valve core 22 moves toward the second hydraulic control chamber 26 under the action of the oil pressure to overcome the action of the return spring 23, and the hydraulic oil is discharged through the valve core oil outlet port A21. Since the discharge end of the valve core oil outlet port A21 is connected to the second hydraulic control chamber 26, the oil pressure at the discharge end acts on the second hydraulic control chamber 26. At this time, the hydraulic forces acting on the first hydraulic control chamber 25 and the second hydraulic control chamber 26 of the pressure compensation valve core 22 have the following relationship:

[0077] (P p -P a )A=k(x0+x)

[0078] Where x is the displacement of the pressure compensation valve core.

[0079] Therefore, in order to ensure a good pressure compensation effect, the displacement of the pressure compensation valve core 22 in the inner cavity of the main valve core 21 can be set to be much smaller than the pre-compression of the return spring 23 in the initial installation state, that is, x<<x0. Therefore, according to the above formula, during the oil inlet and return process, P p -P a Approximately a constant value, the pressure difference between the inlet end and the discharge end of the valve core oil outlet A21 is basically constant, so that the flow through the valve core oil outlet A21 is only related to the sliding position of the valve core assembly 2 in the main valve body 1, and is not affected by load changes.

[0080] Continue to refer to Figures 2 to 4 As shown, a plug screw 24 may be connected to one end of the main valve core 21 to define a second hydraulic control chamber 26 between the plug screw 24 and the pressure compensation valve core 22. A return spring 23 may be installed in the second hydraulic control chamber 26 and abut against the plug screw 24 and the pressure compensation valve core 22 at both ends.

[0081] In addition, in order to facilitate the opening of the valve core oil inlet P21 connected to the first hydraulic control chamber 25 when the pressure compensation valve core 22 slides in the inner cavity of the main valve core 21, a concave structure can be formed at one end of the pressure compensation valve core 22 facing the first hydraulic control chamber 25. Accordingly, the first hydraulic control chamber connecting oil port P22 can be formed in the portion of the pressure compensation valve core 22 corresponding to the first hydraulic control chamber 25, and the first hydraulic control chamber 25 is connected to the valve core oil inlet P21 and the valve core oil outlet A21 through the first hydraulic control chamber connecting oil port P22. When the pressure compensation valve core 22 slides to different positions in the inner cavity of the main valve core 21, the flow cross-sectional area between the valve core oil inlet P21 and the first hydraulic control chamber connecting oil port P22 changes, thereby adjusting the opening of the valve core oil inlet P21 connected to the first hydraulic control chamber 25, so that pressure compensation can be performed according to the pressure difference change before and after the hydraulic oil flows through the valve core oil outlet A21.

[0082] The first hydraulic control cavity communication port P22 may include an oil inlet communication port P221 and an oil outlet communication port P222 distributed along the sliding direction of the pressure compensation valve core 22, wherein when the pressure compensation valve core 22 slides to different positions in the inner cavity of the main valve core 21, the flow cross section between the valve core oil inlet port P21 and the oil inlet communication port P221 changes continuously between full opening and full closing, and the flow cross section between the valve core oil outlet port A21 and the oil outlet communication port P222 always remains constant. To this end, as shown in the figure, the oil outlet communication port P222 may be set to have a length in the sliding direction of the pressure compensation valve core 22 greater than the length of the oil inlet communication port P221, so as to facilitate the change of the flow cross section between the valve core oil inlet port P21 and the oil inlet communication port P221 during the sliding process of the pressure compensation valve core 22, and to keep the valve core oil outlet port A21 and the oil outlet communication port P222 in a fully connected state.

[0083] In order to facilitate the reset spring 23 to apply a stable force to the pressure compensation valve core 22, the end of the pressure compensation valve core 22 facing the second hydraulic control chamber 26 may also be formed with a concave structure. Accordingly, the portion of the main valve core 21 corresponding to the second hydraulic control chamber 26 may be formed with a pressure feedback connecting oil port F21, and the portion of the pressure compensation valve core 22 corresponding to the second hydraulic control chamber 26 may be formed with a second hydraulic control chamber connecting oil port F22, and the second hydraulic control chamber 26 is connected to the discharge end of the valve core oil outlet A21 through the second hydraulic control chamber connecting oil port F22 and the pressure feedback connecting oil port F21 in turn. As a result, the oil pressure at the discharge end of the valve core oil outlet A21 can act on the pressure compensation valve core 22 in the second hydraulic control chamber 26. Through the above arrangement, the length space of the valve core assembly 2 can be fully utilized, the compactness is further improved, and the volume of the hydraulic control module is reduced.

[0084] In order to clearly illustrate the technical solution and working principle of the utility model, the above only describes the hydraulic control system and hydraulic control valve group corresponding to the same hydraulic actuator in combination with the accompanying drawings. In a hydraulic control system of a preferred embodiment of the utility model, Figure 6 As shown, it may include a main oil inlet oil passage L P The variable pump 400 on the upper part and the plurality of hydraulic control valve groups 100 respectively connected to the hydraulic actuator 200, such as the first hydraulic control valve group 110 and the second hydraulic control valve group 120 shown in the figure, each hydraulic control valve group can be formed into a working connection and correspondingly installed on the hydraulic actuator 200 such as the boom oil cylinder, used as a distributed boom valve to control different boom actions respectively, and form an oil supply system similar to the bus power supply mode. Therefore, each hydraulic control valve group 100 is connected in parallel with each other, and its oil inlet P can be connected from the main oil inlet oil circuit L as needed. P To obtain the required hydraulic oil, the return oil port T and the pilot return oil port Y are connected through the main return oil line LT This design can greatly reduce the number of hydraulic control system pipelines, reduce system leakage points and reduce piping costs, and effectively improve the actuator response time. A Or the second working oil circuit L B A hydraulically controlled one-way valve 16 may be provided at a position adjacent to the first working oil port A and the second working oil port B on the upper or lower hydraulic control valve group 100 to realize a self-locking function when the hydraulic actuator 200 is not in operation. Figure 1 and Figure 2 The described implementation methods are the same and will not be repeated here.

[0085] The above-mentioned hydraulic control system and hydraulic control valve group are suitable for occasions where it is necessary to smoothly control the hydraulic actuator under different load conditions, such as the arm extension and retraction control of a concrete pump truck, the lifting and lowering control of a lifting platform, etc. Based on the above, the utility model also provides an operating equipment including the above-mentioned hydraulic control valve group or hydraulic control system, and the operating equipment can be various types of operating equipment with hydraulic actuators, such as engineering machinery, agricultural machinery, and operating robots. Typically, the operating equipment can be a concrete pump truck, which includes a plurality of the above-mentioned hydraulic control valve groups respectively connected (such as plate-type connection) to the boom cylinder.

[0086] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various specific technical features in any suitable manner. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations. However, these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A hydraulic control valve group (100), the hydraulic control valve group (100) comprising an oil inlet (P), an oil return port (T), and a first working oil port (A) and a second working oil port (B) respectively connected to different working chambers of a hydraulic actuator (200), characterized in that: The hydraulic control valve group (100) comprises: a first oil inlet pressure compensation valve (111), the first oil inlet pressure compensation valve (111) being arranged in the oil path portion between the oil inlet port (P) and the first working oil port (A); a first oil return pressure compensation valve (112), the first oil return pressure compensation valve (112) being arranged in an oil passage portion between the first working oil port (A) and the oil return port (T); a second oil inlet pressure compensation valve (113), the second oil inlet pressure compensation valve (113) being arranged in the oil passage portion between the oil inlet port (P) and the second working oil port (B); and A second oil return pressure compensation valve (114) is provided in the oil passage between the second working oil port (B) and the oil return port (T).

2. The hydraulic control valve assembly (100) according to claim 1, characterized in that: The hydraulic control valve group (100) comprises: a first oil inlet flow control valve (121) disposed in the oil circuit portion between the oil inlet port (P) and the first working oil port (A); when oil is supplied to the hydraulic actuator (200) through the first working oil port (A), the first oil inlet pressure compensation valve (111) adjusts the valve opening according to the pressure difference before and after the hydraulic oil flows through the first oil inlet flow control valve (121), so as to keep the pressure difference before and after the first oil inlet flow control valve (121) constant; a first oil return flow control valve (122) disposed in the oil circuit portion between the first working oil port (A) and the oil return port (T); when the hydraulic actuator (200) returns oil through the first working oil port (A), the first oil return pressure compensation valve (112) adjusts the valve opening according to the pressure difference before and after the hydraulic oil flows through the first oil return flow control valve (122), so as to keep the pressure difference before and after the first oil return flow control valve (122) constant; a second oil inlet flow control valve (123) disposed in the oil path between the oil inlet port (P) and the second working oil port (B); when oil is supplied to the hydraulic actuator (200) through the second working oil port (B), the second oil inlet pressure compensation valve (113) adjusts the valve opening according to the pressure difference before and after the hydraulic oil flows through the second oil inlet flow control valve (123), so as to keep the pressure difference before and after the second oil inlet flow control valve (123) constant; and A second return oil flow control valve (124) is arranged in the oil circuit portion between the second working oil port (B) and the return oil port (T). When the hydraulic actuator (200) returns oil through the second working oil port (B), the second return oil pressure compensation valve (114) adjusts the valve opening according to the pressure difference before and after the hydraulic oil flows through the second return oil flow control valve (124), so as to keep the pressure difference before and after the second return oil flow control valve (124) constant.

3. The hydraulic control valve assembly (100) according to claim 2, characterized in that: The hydraulic control valve group (100) has a main valve body (1), and the oil inlet (P), the oil return port (T) and the first working oil port (A) and the second working oil port (B) are arranged on the main valve body (1); at least one of the first oil inlet pressure compensation valve (111) and the first oil inlet flow control valve (121), the first return oil pressure compensation valve (112) and the first return oil flow control valve (122), the second oil inlet pressure compensation valve (113) and the second oil inlet flow control valve (123), and the second return oil pressure compensation valve (114) and the second return oil flow control valve (124) has an integrated valve core component (2), and the valve core component (2) can be slidably installed in the main valve body (1) so as to be controlled to adjust the flow rate of the valve core component (2).

4. The hydraulic control valve assembly (100) according to claim 3, characterized in that: The valve core assembly (2) comprises a main valve core (21) which is slidably matched with the main valve body (1), a pressure compensation valve core (22) which is slidably installed in the inner cavity of the main valve core (21), and a return spring (23) which elastically abuts against one end of the pressure compensation valve core (22). The two ends of the pressure compensation valve core (22) are provided with a first hydraulic control cavity (25) and a second hydraulic control cavity (26). The return spring (23) is arranged in the second hydraulic control cavity (26). The portion of the main valve core (21) corresponding to the first hydraulic control cavity (25) is formed with a valve core oil inlet ( The main valve core (21) is provided with a main valve core (21) and a valve core oil outlet (A21) to allow the hydraulic oil introduced into the first hydraulic control chamber (25) through the valve core oil inlet (P21) to be discharged through the valve core oil outlet (A21); the second hydraulic control chamber (26) is connected to the discharge end of the valve core oil outlet (A21) to enable the pressure compensation valve core (22) to slide in the inner cavity of the main valve core (21) and adjust the opening of the valve core oil inlet (P21) to be connected to the first hydraulic control chamber (25) according to the pressure difference before and after the hydraulic oil flows through the valve core oil outlet (A21).

5. The hydraulic control valve assembly (100) according to claim 4, characterized in that: One end of the main valve core (21) is connected to a screw plug (24) to define the second hydraulic control chamber (26) between the screw plug (24) and the pressure compensation valve core (22), and both ends of the return spring (23) are respectively abutted against the screw plug (24) and the pressure compensation valve core (22).

6. The hydraulic control valve assembly (100) according to claim 4, characterized in that: The portion of the pressure compensation valve core (22) corresponding to the first hydraulic control chamber (25) is formed with a first hydraulic control chamber connecting oil port (P22), and the first hydraulic control chamber (25) is connected to the valve core oil inlet (P21) and the valve core oil outlet (A21) respectively through the first hydraulic control chamber connecting oil port (P22); the portion of the main valve core (21) corresponding to the second hydraulic control chamber (26) is formed with a pressure feedback connecting oil port (F21), and the portion of the pressure compensation valve core (22) corresponding to the second hydraulic control chamber (26) is formed with a second hydraulic control chamber connecting oil port (F22), and the second hydraulic control chamber (26) is connected to the discharge end of the valve core oil outlet (A21) through the second hydraulic control chamber connecting oil port (F22) and the pressure feedback connecting oil port (F21) in sequence.

7. The hydraulic control valve assembly (100) according to claim 6, characterized in that: The first hydraulic control chamber connecting oil port (P22) includes an oil inlet connecting oil port (P221) and an oil outlet connecting oil port (P222) distributed along the sliding direction of the pressure compensation valve core (22), wherein when the pressure compensation valve core (22) slides to different positions in the inner cavity of the main valve core (21), the flow cross section between the valve core oil inlet port (P21) and the oil inlet connecting oil port (P221) continuously changes between fully open and fully closed, and the flow cross section between the valve core oil outlet port (A21) and the oil outlet connecting oil port (P222) always remains constant.

8. The hydraulic control valve assembly (100) according to claim 2, characterized in that: The first oil inlet flow control valve (121), the first oil return flow control valve (122), the second oil inlet flow control valve (123) and the second oil return flow control valve (124) are respectively hydraulically controlled flow valves, and the hydraulic control valve group (100) further comprises an electrically proportional pressure reducing valve (13) which is respectively arranged on the oil circuit portion between the oil inlet port (P) and the respective hydraulic control cavities of the first oil inlet flow control valve (121), the first oil return flow control valve (122), the second oil inlet flow control valve (123) and the second oil return flow control valve (124).

9. The hydraulic control valve assembly (100) according to claim 1, characterized in that: The hydraulic control valve group (100) comprises: a first overflow oil replenishing valve (141), which is arranged in parallel with the first return oil pressure compensation valve (112) in the oil passage between the first working oil port (A) and the return oil port (T) so as to be able to overflow the return oil from the first working oil port (A) through the return oil port (T) or replenish oil to the first working oil port (A); A second overflow oil supply valve (142) is provided in parallel with the second return oil pressure compensation valve (114) in the oil passage between the second working oil port (B) and the return oil port (T) so as to be able to overflow the return oil from the second working oil port (B) through the return oil port (T) or supply oil to the second working oil port (B).

10. A hydraulic control system, comprising a main oil inlet circuit (L P )、Main oil return line (L T ), and first working oil passages (L ) connected to different working chambers of the hydraulic actuator (200) respectively. A ) and the second working oil circuit (L B ) and can be controlled so that the main oil inlet oil circuit (L P ) and the main oil return line (L T ) are selectively connected to the first working oil passage (L A ) or the second working oil circuit (L B ) of a hydraulic control valve group (100), characterized in that: The hydraulic control valve group (100) comprises: A first oil inlet pressure compensation valve (111), the first oil inlet pressure compensation valve (111) is arranged in the main oil inlet oil circuit (L P ) and the first working oil circuit (L A ) between the oil passages, and can be made by the first working oil passage (L A ) when oil is fed into the hydraulic actuator (200), the valve opening is adjusted by receiving pressure feedback to maintain the oil inlet flow rate; A first return oil pressure compensation valve (112) is provided in the first working oil circuit (L A ) and the main oil return line (L T ) between the oil circuit portion, and can be in the hydraulic actuator (200) by the first working oil circuit (L A ) When returning oil, the valve opening is adjusted by receiving pressure feedback to maintain the return oil flow; A second oil inlet pressure compensation valve (113) is provided in the main oil inlet oil circuit (L P ) and the second working oil circuit (L B ) between the oil passages, and can be made by the second working oil passage (L B ) when oil is fed into the hydraulic actuator (200), adjusting the valve opening by receiving pressure feedback to maintain the oil feed flow rate; and, A second return oil pressure compensation valve (114) is provided in the second working oil circuit (L B ) and the main oil return line (L T ) between the oil circuit portion, and can be in the hydraulic actuator (200) by the second working oil circuit (L B ) When returning oil, the valve opening is adjusted by receiving pressure feedback to maintain the return oil flow.

11. The hydraulic control system according to claim 10, characterized in that: The hydraulic control valve group (100) is a hydraulic control valve group (100) according to any one of claims 1 to 9.

12. The hydraulic control system according to claim 10, characterized in that: The hydraulic control system includes a main oil inlet circuit (L P ) and a plurality of hydraulic control valve groups (100) respectively connected to the hydraulic actuators (200).

13. An operating device, characterized in that: The working equipment comprises a hydraulic control valve assembly (100) according to any one of claims 1 to 9 or a hydraulic control system according to any one of claims 10 to 12.

14. The working equipment according to claim 13, characterized in that: The operating equipment is a concrete pump truck, and the plurality of hydraulic control valve groups (100) are respectively connected to the boom cylinders of the concrete pump truck.

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