WO2023103208A1

WO2023103208A1 - Synchronous control valve, hydraulic control system and work machine

Info

Publication number: WO2023103208A1
Application number: PCT/CN2022/081263
Authority: WO
Inventors: 刘玉湘; 赵汗青; 何勤求
Original assignee: 湖南三一华源机械有限公司
Priority date: 2021-12-09
Filing date: 2022-03-16
Publication date: 2023-06-15
Also published as: CN216666065U

Abstract

A synchronous control valve, comprising a shuttle valve (12) and two first load sensitive valve groups (11). Each first load sensitive valve group comprises a reversing valve (111) and a differential pressure valve (112); the differential pressure valve is connected in series to a conduction oil path of the reversing valve; a first end and a second end of the shuttle valve are connected to the two first load sensitive valve groups in a one-to-one correspondence, and a third end of the shuttle valve is separately connected to feedback ends of two differential pressure valves. Also disclosed are a hydraulic control system and a work machine. The synchronous control valve simplifies an oil path structure while synchronously driving two oil cylinders, thereby improving the reliability of the synchronous control of the two oil cylinders.

Description

Synchronous control valve, hydraulic control system and working machinery

This application claims the priority of the Chinese patent application with the application number 202123081005.6 and the title of the invention "Synchronous control valve, hydraulic control system and working machinery" filed on December 09, 2021, which is incorporated herein by reference in its entirety.

technical field

The application relates to the technical field of hydraulic control, and relates to a synchronous control valve, a hydraulic control system and an operating machine.

Background technique

Motor graders and other working machines use the left and right cylinders to drive the working mechanism. However, the rigidity of the working mechanism itself ensures that the left and right cylinders move synchronously, and the reliability of synchronous control is low.

Contents of the invention

The application provides a synchronous control valve, a hydraulic control system and a working machine, which are used to solve or improve the technical problem of low reliability of synchronous control.

The present application provides a synchronous control valve, including: a shuttle valve and two sets of first load sensing valve groups; each group of the first load sensing valve group includes a reversing valve and a differential pressure valve; the reversing valve includes an oil inlet port, the first working port, the second working port, the first middle port, the second middle port and the oil return port; The differential pressure valve is connected in series on the conducting oil path between the first intermediate port and the second intermediate port. In the first working condition, the second intermediate port and the return port One of the oil ports is connected to the first working port, and the other is connected to the second working port. In the second working condition, the second intermediate port, the first working port, and the The second working ports are all in communication with the oil return port; the first end and the second end of the shuttle valve are in communication with the second middle ports of the two groups of the first load sensing valve group in one-to-one correspondence, the The third end of the shuttle valve communicates with the feedback ends of the two differential pressure valves respectively.

Preferably, the synchronous control valve further includes: an overflow valve: the oil inlet ports of the two reversing valves are connected, and the oil return ports of the two reversing valves are connected; The pilot end communicates with the oil inlet respectively, the oil outlet end of the overflow valve communicates with the oil return port; the third end of the shuttle valve communicates with the feedback end of the overflow valve.

Preferably, the reversing valve includes: a first port, a second port, a third port, a fourth port, a fifth port, a sixth port and a seventh port; the first port is the oil inlet, The second port is the first working port, the third port is the second working port, the fourth port is the first intermediate port, and the second intermediate port includes the fifth port and the sixth port, the seventh port is the oil return port; the fourth port communicates with the oil inlet port and the pilot port of the differential pressure valve respectively, and the oil outlet port of the differential pressure valve It communicates with the fifth port; the fifth port communicates with the sixth port, and the sixth port communicates with the first end or the second end of the shuttle valve; the first working condition includes the second state and a third state, the second working condition includes the first state; when the reversing valve is in the first state, the first port is blocked from the fourth port, the second port, The third port, the fifth port, the sixth port and the seventh port are connected respectively; when the reversing valve is in the second state, the first port and the first port The four ports are connected, the fifth port communicates with the third port, and the second port communicates with the seventh port; when the reversing valve is in the third state, the first port It is connected to the fourth port, the fifth port is connected to the second port, and the third port is connected to the seventh port.

Preferably, in the first working condition, the first port communicates with the fourth port through a throttling passage; wherein, the opening degrees of the throttling passages in the two reversing valves are the same, and the two The initial opening pressures of the differential pressure valves are the same; or, the opening degrees of the throttling passages in the two reversing valves are the same, and the initial opening pressures of the two differential pressure valves are different; or, the two reversing valves have different initial opening pressures; The openings of the throttling passages in the reversing valves are different, and the initial opening pressures of the two differential pressure valves are the same.

Preferably, the synchronous control valve further includes: a linkage handle; the linkage handle is respectively connected to the valve stems of the two reversing valves to control the synchronous movement of the valve stems of the two reversing valves; or, it also includes: A control module; the control module is electrically connected to the two reversing valves respectively, so as to control the valve stems of the two reversing valves to move synchronously.

Preferably, the shuttle valve includes a first shuttle valve and a second shuttle valve, the first end of the first shuttle valve is used to connect with the hydraulic actuator, the second end of the first shuttle valve is connected to the two One of the reversing valves is connected, the third end of the first shuttle valve is connected to the first end of the second shuttle valve, and the second end of the second shuttle valve is connected to the two reversing valves. The other of the valves is connected, and the third end of the second shuttle valve is connected with the feedback end of the differential pressure valve.

The present application also provides a hydraulic control system, including: a pressure oil source, two oil cylinders, and the aforementioned synchronous control valve; the pressure oil source communicates with the main oil inlet of the synchronous control valve, and the main oil inlet It is connected with the oil inlet ports of two reversing valves, and the two reversing valves correspond to the two oil cylinders one by one, and one of the first working port and the second working port of each of the reversing valves is connected with the The rod chamber of the oil cylinder is connected, and the other is connected with the rodless chamber of the oil cylinder, so as to control the synchronous action of the piston rods of the two oil cylinders.

Preferably, the hydraulic control system further includes: a priority valve and a filling valve; the pressure oil source communicates with the oil inlet end of the priority valve and the oil inlet end of the filling valve respectively; the first The oil outlet is connected to the steering oil circuit, the second oil outlet of the priority valve is connected to the main oil inlet of the synchronous control valve, the first oil outlet of the filling valve is connected to the brake oil circuit, The second oil outlet of the filling valve is connected to the hydraulic actuator through the second load sensing valve group; or, the first oil outlet of the priority valve is connected to the steering oil circuit, and the second outlet of the priority valve The oil end is connected to the hydraulic actuator through the second load sensing valve group, the first oil outlet of the filling valve is connected to the brake oil circuit, and the second oil outlet of the filling valve is connected to the synchronous control valve. or, the first oil outlet of the priority valve communicates with the steering oil circuit, the first oil outlet of the filling valve communicates with the brake oil circuit, and the second oil outlet of the priority valve communicates with the steering oil circuit. The oil outlet and the second oil outlet of the filling valve are respectively communicated with the main oil inlet of the synchronous control valve; wherein, the priority valve is used to preferentially supply oil to the steering oil circuit, and the filling valve Used to preferentially fill the brake oil circuit.

Preferably, a third shuttle valve is also included, the first end of the third shuttle valve is connected to the reversing valve of the second load sensing valve group, and the second end of the third shuttle valve is used for connecting with the The hydraulic actuator is connected, and the third end of the third shuttle valve is respectively connected with the differential pressure valve and the overflow valve of the second load sensing valve group.

Preferably, the pressure oil source includes a rotary drive mechanism, a first oil pump and a second oil pump; the rotary drive mechanism is respectively connected to the first oil pump and the second oil pump to drive the first oil pump and the second oil pump. The second oil pump operates synchronously; the first oil pump is connected to the priority valve, and the second oil pump is connected to the filling valve.

Preferably, it also includes: a balance valve; the reversing valve corresponding to the synchronous control valve is connected to the oil cylinder through the balance valve; and/or, it also includes: a filter; the synchronous control valve passes through the filter Connect with fuel tank.

The present application also provides an operating machine, including: a frame, an operating mechanism, and the above-mentioned hydraulic control system; the frame is respectively connected to one end of the two oil cylinders, and the other ends of the two oil cylinders are respectively Operating mechanism connection.

Preferably, the two oil cylinders of the hydraulic control system are arranged symmetrically on both sides of the frame, one ends of the two oil cylinders are respectively hinged to the frame, and the other ends of the two oil cylinders are respectively connected to the working Mechanism hinged.

A synchronous control valve, a hydraulic control system and an operating machine provided by the present application can control the two sets of first load-sensing valve groups corresponding to the reversing valves during use by setting two groups of first load-sensing valve groups and shuttle valves. The valve stem moves synchronously, based on the fact that the two reversing valves can divide the flow and control the telescopic action of the two oil cylinders synchronously; when the loads of the two oil cylinders are unbalanced, based on the comparison of the oil pressure after the two differential pressure valves are turned on by the shuttle valve and The feedback of the pressure difference valve, on the basis of ensuring the same relief pressure of the two pressure difference valves, meets the oil supply demand for the oil cylinder with a large eccentric load, while realizing synchronous driving of the two oil cylinders, simplifying the oil The circuit structure improves the reliability of the synchronous control of the two oil cylinders.

Description of drawings

In order to more clearly illustrate the technical solutions in this application or the prior art, the accompanying drawings that need to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings in the following description are the present For some embodiments of the application, those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is the structural representation of synchronous control valve provided by the present application;

Fig. 2 is one of the structural representations of the hydraulic control system provided by the present application;

Fig. 3 is the second structural diagram of the hydraulic control system provided by the present application;

Fig. 4 is the third structural diagram of the hydraulic control system provided by the present application;

Fig. 5 is the fourth schematic structural view of the hydraulic control system provided by the present application;

Fig. 6 is a schematic structural view of the working machine provided by the present application;

Reference signs:

1: Synchronous control valve; 2: Pressure oil source; 3: Oil cylinder;

4: Priority valve; 5: Filling valve; 6: Second load sensing valve group;

7: Balance valve; 8: Filter; 11: The first load sensing valve group;

12: Shuttle valve; 13: Relief valve; 111: Reversing valve;

112: differential pressure valve; 100: frame; 200: operating mechanism;

300: linked boom.

Detailed ways

A synchronous control valve, a hydraulic control system and a working machine of the present application are described below with reference to FIGS. 1-6 .

As shown in Figure 1, the synchronous control valve 1 includes: a first load sensing valve group 11 and a shuttle valve 12; the first load sensing valve group 11 is provided with two groups; each group of the first load sensing valve group 11 includes a reversing valve 111 With the differential pressure valve 112, the reversing valve 111 includes an oil inlet, a first working port, a second working port, a first intermediate port, a second intermediate port and an oil return port; in each reversing valve 111, the oil inlet The port is selectively connected to and disconnected from the first intermediate port, and the differential pressure valve 112 is connected in series on the conducting oil circuit between the first intermediate port and the second intermediate port. When the reversing valve 111 is in the first working condition , one of the second intermediate port and the oil return port of the reversing valve 111 is connected to the first working port, and the other is connected to the second working port. When the reversing valve 111 is in the second working condition, The second intermediate port, the first working port and the second working port of the reversing valve 111 are all in communication with the oil return port.

The first end and the second end of the shuttle valve 12 communicate with the second middle ports of the two first load sensing valve groups 11 in one-to-one correspondence, so as to compare the oil pressure after the two differential pressure valves 112 are turned on. The third end of the valve 12 communicates with the feedback ends of the two differential pressure valves 112 respectively.

By setting two sets of first load-sensing valve groups 11 and shuttle valves 12, during use, the valve stems of the two sets of first load-sensing valve groups 11 corresponding to the reversing valve 111 can be controlled to move synchronously. Based on the two reversing valves 111, the Shunt synchronously controls the expansion and contraction of the two oil cylinders 3; when the loads of the two oil cylinders 3 are unbalanced, based on the comparison of the oil pressure after the shuttle valve 12 conducts the two pressure difference valves 112 and the feedback to the pressure difference valve 112, On the basis of ensuring that the relief pressures of the two differential pressure valves 112 are the same, the oil supply demand for the oil cylinder 3 with a large eccentric load is met, and while realizing synchronous driving of the two oil cylinders 3, the oil circuit structure is simplified and the oil circuit structure is improved. The reliability of the synchronous control of the two oil cylinders 3 is improved.

The synchronous control valve is suitable for synchronous control of two oil cylinders with the same specifications. In the first aspect, the oil inlet ports of the two reversing valves 111 are connected, and the oil return ports of the two reversing valves 111 are connected. In this way, the two The oil pressures of the oil inlets of the two reversing valves 111 are the same. Since the first end and the second end of the shuttle valve 12 are respectively used to detect the oil pressure after the conduction of the two differential pressure valves 112, when the oil pressure of one of the oil cylinders 3 is high due to a large eccentric load, based on the shuttle valve 12 Comparing the oil pressure at the first end and the second end, the shuttle valve 12 can feed back the oil with the higher oil pressure to the feedback ends of the two differential pressure valves 112 at the same time, so that the relief of the two differential pressure valves 112 The pressure is the same, the oil pressure of the first middle port of the two reversing valves 111 is the same, and meets the oil supply demand for the oil cylinder 3 with a relatively large eccentric load. Wherein, in the case that the structures of the two reversing valves 111 are completely the same, the same flow splitting of the two reversing valves 111 can be realized.

In the second aspect, a linkage handle can also be provided to connect the linkage handles to the valve stems of the two reversing valves 111 respectively. When the operator drives the linkage handle to move manually or mechanically, the two reversing valves 111 can be controlled. The valve stems move synchronously, and ensure that the openings of the two reversing valves 111 remain the same.

A control module can also be provided, and the control module is electrically connected with the two reversing valves 111 respectively, so as to control the valve stems of the two reversing valves 111 to move synchronously. The control module can be a PLC controller or a single-chip microcomputer, and the reversing valve 111 can be an electromagnetic reversing valve.

Further, the synchronous control valve 1 also includes: an overflow valve 13; the overflow valve 13 is arranged between the oil inlet and the oil return port of the two reversing valves 111; the third end of the shuttle valve 12 and the overflow valve 13 The feedback terminal is connected.

As shown in Figure 1, the relief valve 13 is a pilot-operated relief valve, the oil inlet end and the pilot end of the relief valve 13 communicate with the oil inlet ports of the two reversing valves 111 respectively, and the oil outlet end of the relief valve 13 It communicates with the oil return ports of the two reversing valves 111. Based on the setting of the relief valve 13, after the shuttle valve 12 compares the oil pressures after the conduction of the two differential pressure valves 112, the shuttle valve 12 feeds back the oil with the highest oil pressure to the feedback end of the relief valve 13, While ensuring the oil pressure at the oil inlets of the two reversing valves 111 is the same, the oil pressure required by the two oil cylinders 3 under different loads is ensured, and when the eccentric load of one of the oil cylinders 3 is large, it can be based on the overflow The overflow control of the flow valve 13 ensures the action speed of the two oil cylinders 3 .

As shown in Figure 1, the reversing valve 111 includes: a first port, a second port, a third port, a fourth port, a fifth port, a sixth port and a seventh port; where the first port is an oil inlet, The seventh port is the oil return port, and the first port to the seventh port are marked as a, b, c, d, e, f, g in sequence.

The first port of the reversing valve 111 is the above-mentioned oil inlet, the second port is the above-mentioned first working port, the third port is the above-mentioned second working port, the fourth port is the above-mentioned first middle port, and the second middle port includes the first working port. The fifth port and the sixth port, the seventh port is the oil return port mentioned above.

As shown in Figure 1, the first port of the reversing valve 111 communicates with the fourth port; the fourth port communicates with the oil inlet port and the pilot port of the differential pressure valve 112 respectively, and the oil outlet port of the differential pressure valve 112 communicates with the fifth port Communication; the fifth port communicates with the sixth port, wherein the sixth port of one reversing valve 111 communicates with the first end of the shuttle valve 12, and the sixth port of the other reversing valve 111 communicates with the second end of the shuttle valve 12 .

The second port of the reversing valve 111 communicates with the rod chamber of the oil cylinder 3 , and the third port of the reversing valve 111 communicates with the rodless chamber of the oil cylinder 3 .

As shown in FIG. 1 and FIG. 2 , the reversing valve 111 has a first state, a second state and a third state, the first working condition includes the second state and the third state, and the second working condition includes the first state.

When the reversing valve 111 is in the first state, the valve stem of the reversing valve 111 is in the neutral position, and the first port and the fourth port of the reversing valve 111 are blocked; the second port and the third port of the reversing valve 111 , the fifth port, the sixth port and the seventh port communicate with the main oil return port T of the synchronous control valve 1 respectively.

When the reversing valve 111 is in the second state, the first port of the reversing valve 111 communicates with the fourth port, the fifth port communicates with the third port, and the second port communicates with the seventh port; the flow of hydraulic oil The sequence is as follows: the first port of the reversing valve 111, the fourth port of the reversing valve 111, the oil inlet port of the differential pressure valve 112, the oil outlet port of the differential pressure valve 112, the fifth port of the reversing valve 111, the reversing valve The third port of the reversing valve 111 and the rodless chamber of the oil cylinder 3; the hydraulic oil in the rod chamber of the oil cylinder 3 flows back to the synchronous control valve 1 through the second port of the reversing valve 111 and the seventh port of the reversing valve 111 in sequence The main oil return port T.

During this process, after the oil pressure at the sixth port of the two reversing valves 111 is compared by the shuttle valve 12, the shuttle valve 12 will feed back the large load oil pressure to the feedback port of the differential pressure valve 112 to provide the required load for driving the load. required oil pressure. The two reversing valves 111 realize the split flow control of the piston rods of the two oil cylinders 3 to extend out synchronously, which can solve the problem that the operating mechanism bears a large partial load due to the asynchronous actions of the left oil cylinder 3 and the right oil cylinder 3, and improves the operating mechanism. work reliability.

When the reversing valve 111 is in the third state, the first port of the reversing valve 111 communicates with the fourth port, the fifth port of the reversing valve 111 communicates with the second port, and the third port communicates with the seventh port. . At this time, the flow sequence of the hydraulic oil is as follows: the first port of the reversing valve 111, the fourth port of the reversing valve 111, the oil inlet end of the differential pressure valve 112, the oil outlet end of the differential pressure valve 112, the reversing valve 111 of the fifth port, the second port of the reversing valve 111 and the rod chamber of the oil cylinder 3; in addition, the hydraulic oil in the rodless chamber of the oil cylinder 3 passes through the third port of the reversing valve 111, the reversing valve 111 in turn. The seventh port returns to the main oil return port T of the synchronous control valve 1.

After the oil pressure at the sixth port of the two reversing valves 111 is compared by the shuttle valve 12, the shuttle valve 12 feeds back the large load oil pressure to the feedback port of the differential pressure valve 112 to provide the required oil pressure for driving the load. The two reversing valves 111 realize the diversion control of the synchronous retraction of the piston rods of the two oil cylinders 3, which can solve the problem that the operating mechanism 200 bears a large eccentric load due to the asynchronous actions of the left oil cylinder 3 and the right oil cylinder 3, and improve the operation efficiency. Agency 200 work reliability.

When the reversing valve 111 is in the first working condition, the first port of the reversing valve 111 communicates with the fourth port through the throttling passage, and when the reversing valve 111 is in the second working condition, the reversing valve 111 The throttling channel between the first port and the fourth port is blocked; in order to ensure that the synchronization accuracy of the extension and retraction of the two oil cylinders 3 is the same, the two reversing valves 111 can be set to be in the first working condition The opening degrees of the throttle passages are the same, and the initial opening pressures of the two differential pressure valves 112 are the same.

Due to the comparison based on the shuttle valve 12 and the feedback adjustment to the opening of the differential pressure valve 112, it is ensured that the fourth ports of the two reversing valves 111 maintain the same oil pressure; If the oil pressure is the same, the pressure difference between the first port and the fourth port of the two reversing valves 111 is the same. When the initial cracking pressure is the same, the divided flows of the two groups of first load sensing valve groups 11 are the same.

For two oil cylinders with the same specifications, two identical and synchronous reversing valves 111 are used, and the pressure difference between the first port and the fourth port of the two reversing valves 111 is controlled by the differential pressure valve 112 and the relief valve 13 to be the same , so that the two sets of first load-sensing valve groups 11 integrate reversing and same-flow splitting functions, realize synchronous driving of the two oil cylinders 3, simplify the structure, and improve the reliability of the system.

For two oil cylinders with different specifications, in order to realize the synchronous control of the two oil cylinders, when the pressure difference between the first port and the fourth port of the two reversing valves 111 is the same, the pressure in the two reversing valves 111 The openings of the throttling passages are different. For example, the openings of the throttling passages of the two reversing valves 111 are designed in proportion, so that when the initial opening pressures of the two differential pressure valves 112 are the same, the two oil cylinders 3 Different proportions of flow splitting are carried out.

In addition, when the reversing valve 111 is in the first working condition, under the condition that the opening degrees of the throttling passages in the two reversing valves 111 are kept the same, the initial opening pressures of the two differential pressure valves 112 are different, and the two The pressure difference between the first port and the fourth port of the reversing valve 111 is proportional to realize flow splitting of the two oil cylinders 3 in different proportions.

The initial cracking pressure of the differential pressure valve 112 is determined by the type of the spring provided at the feedback end of the differential pressure valve 112; The model is determined.

As shown in Figure 2, a hydraulic control system includes: a pressure oil source 2, two oil cylinders 3 and the aforementioned synchronous control valve 1; the pressure oil source 2 communicates with the main oil inlet P of the synchronous control valve 1, and the main inlet The oil port P is connected to the oil inlet ports of the two reversing valves, and the two reversing valves correspond to the two oil cylinders one by one. One of the first working port and the second working port of each reversing valve is connected with the cylinder The rod cavity is connected, and the other is connected with the rodless cavity of the oil cylinder to control the synchronous action of the piston rods of the two oil cylinders.

Since the hydraulic control system includes the synchronous control valve 1 , it has all the beneficial effects of the above synchronous control valve 1 .

Preferably, the hydraulic control system further includes: a balance valve 7 ; the reversing valve 111 corresponding to the synchronous control valve 1 is connected to the oil cylinder 3 through the balance valve 7 .

As shown in Figure 2, when the reversing valve 111 is in the first state, since the oil inlet port of the balance valve 7 communicates with the main oil return port T of the synchronous control valve 1 through the reversing valve 111, the balance valve 7 is in a closed state, Thus, the oil circuits of the two cylinders 3 are locked to ensure that the positions of the piston rods of the two cylinders 3 remain unchanged. Only when the load force on the cylinder 3 is greater than the overflow pressure of the balance valve 7, the balance valve 7 will perform overflow flow for overload protection.

When the reversing valve 111 is in the second state, the balance valve 7 can ensure that the hydraulic oil entering the main oil inlet P of the synchronous control valve 1 is directed to the rodless cavity of the oil cylinder 3 through the reversing valve 111, and The hydraulic oil in the rod cavity of the oil cylinder 3 returns to the main oil return port T of the synchronous control valve 1 through the reversing valve 111 directionally.

When the reversing valve 111 is in the third state, the balance valve 7 can ensure that the hydraulic oil entering the main oil inlet P of the synchronous control valve 1 is directed to the rod cavity of the oil cylinder 3 through the reversing valve 111, and The hydraulic oil in the rodless chamber of the oil cylinder 3 returns to the main oil return port T of the synchronous control valve 1 through the reversing valve 111 directionally.

The hydraulic control system also includes: a priority valve 4 and a filling valve 5; the pressure oil source 2 is respectively connected to the oil inlet end of the priority valve 4 and the oil inlet end of the filling valve 5; the priority valve 4 is used to preferentially supply oil to the steering oil circuit Oil, filling valve 5 is used to preferentially fill the brake oil circuit.

As shown in Figure 3, the first oil outlet CF of the priority valve 4 communicates with the steering oil passage, the second oil outlet EF of the priority valve 4 communicates with the main oil inlet P of the synchronous control valve, and the first outlet of the filling valve 5 One oil outlet B1 communicates with the brake oil circuit, and the second oil outlet N of the filling valve 5 is connected with the hydraulic actuator through the second load sensing valve group 6 .

When the pressure oil source 2 supplies oil to the main oil inlet P of the priority valve 4, the oil inlet port of the priority valve 4 is preferentially connected to the first oil outlet port CF, and the first oil outlet port CF of the priority valve 4 is used to The steering gear in the steering oil circuit supplies oil, and the steering gear feeds back the hydraulic oil to the LS port of the priority valve 4. When the feedback oil pressure reaches the preset value, the oil inlet port of the priority valve 4 is connected to the second oil outlet port EF, To supply oil to the main oil inlet P of synchronous control valve 1.

When the pressure oil source 2 supplies oil to the oil inlet end of the filling valve 5, the oil inlet end of the filling valve 5 is preferentially connected to the first oil outlet port B1, and the first oil outlet port B1 of the filling valve 5 is used for Supply oil to the accumulator in the brake oil circuit. When the oil pressure of the hydraulic oil stored in the accumulator reaches the preset value, the oil inlet port of the filling valve 5 is connected to the second oil outlet port N, so as to The second load-sensing valve group 6 supplies oil, and the second load-sensing valve group 6 controls hydraulic actuators such as oil cylinders or hydraulic motors to act.

In order to improve the reliability of the operation of the entire hydraulic control system, the shuttle valve 12 specifically includes a first shuttle valve and a second shuttle valve. The first end of the first shuttle valve is connected to the feedback end of the hydraulic actuator. For example, the hydraulic actuator can be Steering gear, hydraulic motor, etc. on the working machine, the second end of the first shuttle valve is connected to the sixth port of one of the above two reversing valves 111, and the third end of the first shuttle valve is connected to the second port of the second shuttle valve. The first end is connected, the second end of the second shuttle valve is connected with the sixth port of the other of the above-mentioned two reversing valves 111, and the third end of the second shuttle valve is connected with the feedback ports of the two differential pressure valves 112 respectively. And the feedback end of overflow valve 13 is connected. Wherein, the second end of the first shuttle valve is the first end of the shuttle valve 12, the second end of the second shuttle valve is the second end of the shuttle valve 12, and the third end of the second shuttle valve is the first end of the shuttle valve 12. Three ends.

Here, the above-mentioned second load-sensing valve group 6 is configured with a third shuttle valve, and the specific structure of the second load-sensing valve group 6 can refer to the first load-sensing valve group 11 . The oil inlet and oil return ports of the second load sensing valve group 6 are also provided with relief valves as shown in the above embodiments. The first end of the third shuttle valve is connected to the sixth port of the reversing valve 111 of the second load sensing valve group 6, the second end of the third shuttle valve is connected to the feedback end of the hydraulic actuator, and the first end of the third shuttle valve The three ends are connected with the feedback end of the differential pressure valve of the second load sensing valve group 6 and the feedback end of the relief valve of the second load sensing valve group 6 .

As shown in Figure 4, based on the scheme shown in Figure 3, the first oil outlet CF of the priority valve 4 is connected to the steering oil circuit, and the second oil outlet EF of the priority valve 4 is connected to the hydraulic pressure through the second load sensing valve group. The executive element is connected, the first oil outlet B1 of the filling valve 5 is connected with the brake oil circuit, and the second oil outlet N of the filling valve 5 is connected with the main oil inlet P of the synchronous control valve, so as to satisfy the brake pressure. In case of demand, oil is supplied from the charging valve 5 to the main oil inlet P of the synchronous control valve.

As shown in Figure 5, based on the scheme shown in Figure 3 and Figure 4, the first oil outlet CF of the priority valve 4 is connected to the steering oil circuit, and the first oil outlet B1 of the filling valve 5 is connected to the brake oil circuit The second oil outlet EF of the priority valve 4 and the second oil outlet N of the filling valve 5 are respectively connected with the main oil inlet P of the synchronous control valve, so that when the steering and/or braking requirements are met, , oil is supplied from the priority valve 4 and/or the filling valve 5 to the main oil inlet P of the synchronous control valve.

The synchronous control valve 1 can be integrated by the two-way second load-sensing valve group 6 in the original hydraulic control system. In this application, the main oil return port T of the synchronous control valve 1 and/or the oil return port of the second load sensing valve group 6 are connected to the oil tank through a filter 8 to ensure the cleanliness of the hydraulic oil in the hydraulic control system.

The pressure oil source 2 includes a rotary drive mechanism, a first oil pump and a second oil pump; the rotary drive mechanism is respectively connected with the first oil pump and the second oil pump to drive the first oil pump and the second oil pump to run synchronously; the first oil pump and the priority valve 4 Connected, the second oil pump is connected with the filling valve 5.

Wherein, the pressure oil source 2 also includes an oil tank, the first oil pump is used to pump the hydraulic oil in the oil tank to the priority valve 4 , and the first oil pump is used to pump the hydraulic oil in the oil tank to the filling valve 5 . Meanwhile, the rotation driving mechanism may be an engine, and the first oil pump and the second oil pump may be gear pumps or plunger pumps respectively.

As shown in Figure 6, a kind of working machine comprises: frame 100, working mechanism 200 and hydraulic control system as above any one; The other end of each is connected with the operating mechanism 200 respectively. The application is applied to various working machines that have two oil cylinders and require synchronous control of the two oil cylinders, and the working machine may be a motor grader.

Specifically, two oil cylinders 3 are arranged symmetrically on opposite sides of the frame 100 , one ends of the two oil cylinders 3 are respectively hinged to the frame 100 , and the other ends of the two oil cylinders 3 are respectively hinged to the working mechanism 200 . In order to ensure the reliability of the action of the working mechanism 200 , the working machine is also provided with a linkage arm 300 , one end of the linkage arm 300 is hinged to the frame 100 , and the other end of the linkage arm 300 is hinged to the working mechanism 200 .

Wherein, the operating mechanism 200 may be a cutting knife or a loosening rake.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, rather than limiting them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still Modifications are made to the technical solutions described in the foregoing embodiments, or equivalent replacements are made to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present application.

Claims

A synchronous control valve comprising:

Shuttle valve and two sets of first load sensing valve groups;

Each group of the first load sensing valve group includes a reversing valve and a differential pressure valve;

The reversing valve includes an oil inlet, a first working port, a second working port, a first middle port, a second middle port and an oil return port;

In each of the reversing valves, the oil inlet is selectively connected to and disconnected from the first intermediate port, and the differential pressure valve is connected in series with the first intermediate port and the second intermediate port In the first working condition, one of the second intermediate port and the oil return port is connected to the first working port, and the other is connected to the second working port. In the second working condition, the second intermediate port, the first working port, and the second working port are all connected to the oil return port;

The first end and the second end of the shuttle valve communicate with the second intermediate ports of the two groups of the first load sensing valve groups in one-to-one correspondence, and the third end of the shuttle valve communicates with the two pressure differential ports respectively. The feedback port of the valve is connected.
The synchronous control valve according to claim 1, wherein,

Also includes: Relief Valve:

The oil inlets of the two reversing valves are connected, and the oil return ports of the two reversing valves are connected; the oil inlet and the pilot end of the relief valve are respectively connected with the oil inlet, so The oil outlet of the overflow valve is connected with the oil return port; the third end of the shuttle valve is connected with the feedback end of the overflow valve.
The synchronous control valve according to claim 1, wherein,

The reversing valve includes: a first port, a second port, a third port, a fourth port, a fifth port, a sixth port and a seventh port;

The first port is the oil inlet, the second port is the first working port, the third port is the second working port, and the fourth port is the first intermediate port , the second intermediate port includes the fifth port and the sixth port, the seventh port is the oil return port; the fourth port is connected to the oil inlet port and the pilot of the differential pressure valve respectively The oil outlet port of the differential pressure valve is connected with the fifth port; the fifth port is connected with the sixth port, and the sixth port is connected with the first port or the second port of the shuttle valve. end connected;

The first working condition includes a second state and a third state, and the second working condition includes the first state;

When the reversing valve is in the first state, the first port is blocked from the fourth port, the second port, the third port, the fifth port, and the sixth port and the seventh port are respectively turned on;

When the reversing valve is in the second state, the first port communicates with the fourth port, the fifth port communicates with the third port, and the second port communicates with the first port. Seven ports connected;

When the reversing valve is in the third state, the first port communicates with the fourth port, the fifth port communicates with the second port, and the third port communicates with the first port. Seven ports are connected.
The synchronous control valve according to claim 3, wherein,

In the first working condition, the first port communicates with the fourth port through a throttling passage;

Wherein, the openings of the throttling passages in the two reversing valves are the same, and the initial opening pressures of the two differential pressure valves are the same;

Or, the openings of the throttling passages in the two reversing valves are the same, and the initial opening pressures of the two differential pressure valves are different;

Or, the opening degrees of the throttling passages in the two reversing valves are different, and the initial opening pressures of the two differential pressure valves are the same.
The synchronous control valve according to any one of claims 1 to 4, wherein,

It also includes: a linkage handle; the linkage handle is respectively connected to the valve stems of the two reversing valves, so as to control the synchronous movement of the valve stems of the two reversing valves;

Alternatively, it further includes: a control module; the control module is electrically connected to the two reversing valves respectively, so as to control the valve rods of the two reversing valves to move synchronously.
The synchronous control valve according to any one of claims 1 to 4, wherein the shuttle valve comprises a first shuttle valve and a second shuttle valve, the first end of the first shuttle valve is used to connect with a hydraulic actuator, The second end of the first shuttle valve is connected to one of the two reversing valves, the third end of the first shuttle valve is connected to the first end of the second shuttle valve, and the first The second end of the second shuttle valve is connected to the other of the two reversing valves, and the third end of the second shuttle valve is connected to the feedback end of the differential pressure valve.
A hydraulic control system, comprising: a pressure oil source and two oil cylinders, which also includes: the synchronous control valve according to any one of claims 1 to 6; the pressure oil source and the main inlet of the synchronous control valve The oil port is connected, and the main oil inlet is connected with the oil inlets of two reversing valves, and the two reversing valves correspond to the two oil cylinders one by one, and the first work of each reversing valve One of the port and the second working port is connected with the rod chamber of the oil cylinder, and the other is connected with the rodless chamber of the oil cylinder, so as to control the synchronous action of the piston rods of the two oil cylinders.
The hydraulic control system according to claim 7, wherein,

Also includes: priority valve, filling valve, second load sensing valve group and hydraulic actuators;

The pressure oil source communicates with the oil inlet end of the priority valve and the oil inlet end of the filling valve respectively;

The first oil outlet of the priority valve communicates with the steering oil passage, the second oil outlet of the priority valve communicates with the main oil inlet of the synchronous control valve, and the first oil outlet of the filling valve communicated with the brake oil circuit, and the second oil outlet end of the charging valve is connected to the hydraulic actuator through the second load sensing valve group;

Alternatively, the first oil outlet of the priority valve communicates with the steering oil circuit, the second oil outlet of the priority valve is connected with the hydraulic actuator through the second load sensing valve group, and the first oil outlet of the filling valve The oil end communicates with the brake oil circuit, and the second oil outlet end of the filling valve communicates with the main oil inlet port of the synchronous control valve;

Or, the first oil outlet of the priority valve communicates with the steering oil circuit, the first oil outlet of the filling valve communicates with the brake oil circuit, the second oil outlet of the priority valve, the charging The second oil outlet of the liquid valve is respectively communicated with the main oil inlet of the synchronous control valve;

Wherein, the priority valve is used to preferentially supply oil to the steering oil circuit, and the filling valve is used to preferentially fill the brake oil circuit.
The hydraulic control system according to claim 8, further comprising a third shuttle valve, the first end of the third shuttle valve is connected to the reversing valve of the second load sensing valve group, and the third shuttle valve The second end of the valve is used to connect with the hydraulic actuator, and the third end of the third shuttle valve is respectively connected with the differential pressure valve and the overflow valve of the second load sensing valve group.
The hydraulic control system according to claim 8, wherein:

The pressure oil source includes a rotary drive mechanism, a first oil pump and a second oil pump;

The rotation driving mechanism is respectively connected with the first oil pump and the second oil pump to drive the first oil pump and the second oil pump to run synchronously; the first oil pump is connected with the priority valve, and the The second oil pump is connected with the filling valve.
The hydraulic control system according to claim 8, wherein:

It also includes: a balance valve; the first working port and the second working port of the reversing valve are connected to the oil cylinder through the balancing valve; and/or,

Also includes: filter;

The oil discharge port of the synchronous control valve is connected with the oil tank through the filter, and the oil discharge port is connected with the oil return ports of the two reversing valves.
An operating machine, comprising: a frame and an operating mechanism, and further comprising: the hydraulic control system according to any one of claims 7 to 11; the frame is respectively connected to one end of two oil cylinders of the hydraulic control system, The other ends of the two oil cylinders are respectively connected with the working mechanism.
The working machine according to claim 12, wherein the two oil cylinders of the hydraulic control system are arranged symmetrically on both sides of the frame, one ends of the two oil cylinders are respectively hinged to the frame, and the two cylinders are respectively hinged to the frame. The other end of the oil cylinder is respectively hinged with the working mechanism.