Steering valve, hydraulic system and walking equipment

Abstract

The utility model relates to the technical field of hydraulic steering, and provides a steering valve, a hydraulic system and walking equipment, aiming at bidirectional control of a steering oil cylinder, a first steering control module and a second steering control module which are mutually independent are arranged, and the first steering control module and the second steering control module are respectively connected with two ends of the steering oil cylinder; a first pilot valve element and a first main valve element which are in one-to-one correspondence, and a second pilot valve element and a second main valve element which are in one-to-one correspondence are utilized, and in the left / right oil inlet process of the steering oil cylinder, the first main valve element and the second main valve element can independently work and accurately control the flow of oil entering a left cavity and a right cavity of the steering oil cylinder correspondingly; a pilot valve core does not need to be switched and controlled during left-right reversing, so that the response speed and the control precision are effectively improved; meanwhile, the two independent steering control modules can flexibly change the flow direction, pressure and flow supply of oil according to requirements so as to meet the requirements of complex and changeable working conditions.

Description

TECHNICAL FIELD

[0001] The utility model relates to hydraulic steering technical field especially relates to a kind of steering valve, hydraulic system and walking equipment. BACKGROUND

[0002] Steering valve is widely used in various process flows, such as fluid delivery, pressure regulation, temperature control, etc. In the field of mechanical manufacturing, steering valve can be used to realize the reversing motion of machine tool workbench; in the field of chemical industry, steering valve can be used to control the flow direction of reactants; in the field of metallurgy, steering valve can be used to adjust the flow direction of metal liquid; in the field of papermaking, steering valve can be used to control the flow direction of pulp, etc.

[0003] Steering valve plays a role in controlling the direction of fluid in the hydraulic system of engineering machinery. When turning the steering wheel, the steering gear generates pilot oil pressure, which acts on the valve core to make the valve core act, thereby controlling the direction of oil flow and realizing the steering function of the vehicle.

[0004] In the prior art, the Chinese patent "Hydraulic steering control valve and hydraulic steering system" with application number 201410405438.8 discloses a linkage double-valve core design for the selection valve, which controls the reversing of the main valve core by using two pilot valve cores. However, in actual practice, due to the sequence of switching of the two pilot valve cores, there is a difference in the sequence of movement of the two pilot valve cores under different working conditions. When the oil is flowing in, the closing of the valve core on one side of the selection valve can cause delay, so the selection valve cannot respond to the user's reversing demand in a timely manner. UTILITY MODEL CONTENTS

[0005] The utility model provides a kind of steering valve, hydraulic system and walking equipment, solve the technical problem that the response speed of the existing steering valve is slow when reversing switching is carried out due to the sequence of switching of the two pilot valve cores, and the user experience is poor.

[0006] To solve the above technical problems, the utility model provides a kind of steering valve, comprising a first steering control module and a second steering control module connected with a steering gear, the first steering control module and the second steering control module are respectively connected with two ends of a steering oil cylinder.

[0007] The first steering control module comprises a first pilot valve core and a first main valve core; the oil inlet of the first main valve core is connected with the oil outlet of the first pilot valve core, and the oil outlet of the first main valve core is connected with one end of the steering oil cylinder.

[0008] The second steering control module comprises a second pilot valve core and a second main valve core; the oil inlet of the second main valve core is connected with the oil outlet of the second pilot valve core, and the oil outlet of the second main valve core is connected with the other end of the steering oil cylinder.

[0009] In a further embodiment, the first pilot spool comprises a two-position four-way directional valve, an inlet port P of which is connected to the steering gear, outlet ports A and B of which are connected to the first main spool, and an outlet port of the first main spool is connected to one end of the steering cylinder.

[0010] In a further embodiment, the first main spool comprises a two-position six-way directional valve, which is normally in the right position, so that the working inlet port is communicated with the right working oil port, and the left working oil port is communicated with the return oil port.

[0011] The oil from the outlet port of the steering gear enters, and the oil pressure changes the spool position of the first pilot spool to perform directional change; when the oil enters the first main spool, the pressure acts on the control end to control the directional change of the first main spool to perform left-turn inlet oil.

[0012] In a further embodiment, the second pilot spool comprises a two-position four-way directional valve, an inlet port P of which is connected to the steering gear, outlet ports A and B of which are connected to the second main spool, and an outlet port of the second main spool is connected to the other end of the steering cylinder.

[0013] In a further embodiment, the second main spool comprises a two-position six-way directional valve, which is normally in the left position, so that the working inlet port is communicated with the left working oil port, and the right working oil port is communicated with the return oil port.

[0014] The oil from the outlet port of the steering gear enters, and the oil pressure changes the spool position of the second pilot spool to perform directional change; when the oil enters the second main spool, the pressure acts on the control end to control the directional change of the second main spool to perform right-turn inlet oil.

[0015] In a further embodiment, a priority valve and a one-way throttle valve connected to the priority valve are further included, an inlet port P of the priority valve is connected to the tank through a variable pump, a CF port is connected to the inlet port of the steering gear, an EF port is connected to the inlet port of a multi-way valve of a working system, an LS port is connected to the control port of the steering gear, and a T1 port is a return oil port of a safety valve.

[0016] In a further embodiment, a first protection module connected to the first steering control module is further included, the first protection module comprises a first one-way valve and a first oil supplement valve; an outlet port A of the first pilot spool is connected to the left working oil port of the first main spool through the first one-way valve; one end of the first oil supplement valve is connected to the left working oil port of the first main spool in a one-way manner, and the other end is connected to a return oil pipeline.

[0017] After the oil liquid flows out from the first main valve core, the oil liquid is output into the steering oil cylinder through the first one-way valve; meanwhile, the oil liquid pressure acts on the spring cavity end of the first main valve core through the first pilot valve core, so that the opening of the first main valve core is determined by the size of the flow at the oil outlet of the steering gear.

[0018] In a further embodiment, a second protection module connected with the second steering control module is further included, the second protection module comprising a second one-way valve and a second oil supplement valve; the oil outlet B of the second pilot valve core is in one-way communication with the right working oil port of the second main valve core through the second one-way valve; one end of the second oil supplement valve is in one-way communication with the left working oil port of the second main valve core, and the other end is connected with the oil return pipeline.

[0019] After the oil liquid flows out from the second main valve core, the oil liquid is output into the steering oil cylinder through the second one-way valve; meanwhile, the oil liquid pressure acts on the spring cavity end of the second main valve core through the second pilot valve core, so that the opening of the second main valve core is determined by the size of the flow at the oil outlet of the steering gear.

[0020] In a further embodiment, an overflow valve is further included, an oil inlet end of the overflow valve is in communication with the spring cavity of the priority valve, and an oil outlet is in communication with the oil tank through an oil return pipeline.

[0021] In a further embodiment, a first overload valve and a second overload valve are further included; one end of the first overload valve is connected with the right working oil port of the first main valve core, and the other end is connected with the oil return pipeline; one end of the second overload valve is connected with the left working oil port of the second main valve core, and the other end is connected with the oil return pipeline.

[0022] The utility model provides a kind of hydraulic system, including steering oil cylinder and steering gear, steering pump, oil tank connected in turn, and the steering valve as described above, the right working oil port of the first main valve core in the steering valve, the left working oil port of the second main valve core are respectively communicated with the large cavity / small cavity and small cavity / large cavity of steering oil cylinder, and the oil return port of the first main valve core, the second main valve core is communicated with oil tank.

[0023] The utility model further provides a kind of wheeled walking equipment, including the hydraulic system as described above, and the walking equipment includes but is not limited to loader, mining machinery, heavy truck, large forklift, agricultural machinery.

[0024] The utility model has the advantages that:

[0025] (1) For bidirectional control of the steering oil cylinder, a first steering control module and a second steering control module that are independent of each other are arranged, and a one-to-one first pilot valve core and a first main valve core, and a second pilot valve core and a second main valve core are used, so that, in the left / right oil inlet process of the steering oil cylinder, the first main valve core and the second main valve core can independently work and respectively accurately control the oil flow entering the left and right cavities of the steering oil cylinder, and it is not necessary to switch the control pilot valve core when the left and right directions are changed, so that the response speed and control accuracy are effectively improved; meanwhile, the two independent steering control modules can flexibly change the flow direction, pressure and flow supply size of the oil according to requirements, so as to adapt to complex and changeable working condition requirements.

[0026] (2) A one-way valve (first one-way valve and second one-way valve) is arranged between the oil outlet of the main valve core (first main valve core and second main valve core) and the pilot valve core (first pilot valve core and second pilot valve core), so as to limit the reverse flow of the oil, effectively prevent the high-pressure oil of the oil outlet from rebounding to the control cavity of the pilot valve core when the main valve core rapidly switches, avoid pressure impact, and enhance the system stability.

[0027] (3) An oil supplementing one-way valve (first oil supplementing valve and second oil supplementing valve) is connected to the oil outlet of the main valve core (first main valve core and second main valve core), and the oil connected to the return pipeline is timely supplemented to the oil outlet of the main valve core, so as to maintain pressure stability and flow balance, and avoid the influence of system fluctuation on response efficiency.

[0028] (4) An overload valve (first overload valve and second overload valve) is connected to the oil outlet of the main valve core (first main valve core and second main valve core), and a return port is added to the hydraulic cylinder, so that, when the load is overloaded, the overload valve is automatically opened, the hydraulic oil enters the steering oil cylinder, the descending speed of the load is slowed down, and the stable operation of the load is maintained.

[0029] (5) An overflow valve connected with the priority valve is arranged, on one hand, when the steering device works, the hydraulic oil based on the priority valve is preferentially supplied to the steering system, the flexibility and accuracy of steering are ensured, and on the other hand, the overflow valve can control the flow size by adjusting the valve core lift or the spring pre-tightening force, the flow stability is good, the pressure control is accurate, and different flow and pressure requirements of the hydraulic system can be met. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a principle diagram of a steering valve provided by an embodiment of the utility model;

[0031] Figure 2 is a partial principle diagram of a hydraulic system provided by an embodiment of the utility model;

[0032] Figure 3 is a principle diagram of a multi-way valve oil inlet of a working system in a hydraulic system provided by an embodiment of the utility model;

[0033] The components include: first pilot valve core 11, first main valve core 12, first check valve 13, first replenishing valve 14, and first overload valve 15; second pilot valve core 21, second main valve core 22, second check valve 23, second replenishing valve 24, and second overload valve 25; one-way throttle valve 3, overflow valve 4, and throttle orifice 5; steering cylinder 6, steering gear 7, steering pump 8, oil tank 9, and priority valve 10. Detailed Implementation

[0034] The embodiments of this utility model are described in detail below with reference to the accompanying drawings. The embodiments are given for illustrative purposes only and should not be construed as limiting the utility model. The accompanying drawings are for reference and illustration only and do not constitute a limitation on the scope of patent protection of this utility model, because many changes can be made to this utility model without departing from the spirit and scope of this utility model.

[0035] This utility model provides a steering valve, such as Figure 1 As shown, in this embodiment, a first steering control module and a second steering control module are connected to the steering gear 7. The first steering control module and the second steering control module are respectively connected to both ends of the steering cylinder 6.

[0036] The first steering control module includes a first pilot valve core 11 and a first main valve core 12; the oil inlet of the first main valve core 12 is connected to the oil outlet of the first pilot valve core 11, and the oil outlet of the first main valve core 12 is connected to one end S1 of the steering cylinder 6.

[0037] The second steering control module includes a second pilot valve core 21 and a second main valve core 22; the oil inlet of the second main valve core 22 is connected to the oil outlet of the second pilot valve core 21, and the oil outlet of the second main valve core 22 is connected to the other end S2 of the steering cylinder 6.

[0038] In this embodiment, the first pilot valve core 11 includes a two-position four-way directional valve, with its inlet P connected to the steering gear 7, and its outlets A and B connected to the first main valve core 12. The outlet of the first main valve core 12 is connected to one end S1 of the steering cylinder 6.

[0039] In this embodiment, the first main valve core 12 includes a two-position six-way directional valve, which is normally in the right position, so the working oil inlet is connected to the right working oil port, and the left working oil port is connected to the return oil port.

[0040] In the embodiment, the first protection module connected with the first steering control module is further included, and the first protection module includes a first check valve 13 and a first oil supplement valve 14; an oil outlet A of the first pilot valve core 11 is in one-way communication with a left working oil port of the first main valve core 12 through the first check valve 13; one end of the first oil supplement valve 14 is in one-way communication with the left working oil port of the first main valve core 12, and the other end is connected with an oil return pipeline (such as a pipeline connected with an oil return port T in the second protection module). Figure 1

[0041] Specifically, the oil outlet Pa of the steering gear 7 inputs oil, the oil pressure changes the valve core position of the first pilot valve core 11 to perform steering; when the oil enters the first main valve core 12, the pressure acts on the control end to control the steering of the first main valve core 12; the oil flows out of the first main valve core 12 and is output into the steering oil cylinder 6 through the first check valve 13 to perform left turning oil input. At the same time, the oil pressure acts on the spring cavity end of the first main valve core 12 through the first pilot valve core 11, and then the opening of the steering of the first main valve core 12 depends on the size of the flow of the oil outlet Pa of the steering gear 7.

[0042] In the embodiment, the second pilot valve core 21 includes a two-position four-way steering valve, an oil inlet P of which is connected with the steering gear 7, and oil outlets A and B of which are connected with the second main valve core 22; an oil outlet of the second main valve core 22 is connected with the other end S2 of the steering oil cylinder 6.

[0043] In the embodiment, the second main valve core 22 includes a two-position six-way steering valve, which is in a left position in a normal state, so that a working oil inlet and a left working oil port are in communication, and a right working oil port and an oil return port are in communication.

[0044] In the embodiment, the second protection module connected with the second steering control module is further included, and the second protection module includes a second check valve 23 and a second oil supplement valve 24; an oil outlet B of the second pilot valve core 21 is in one-way communication with a right working oil port of the second main valve core 22 through the second check valve 23; one end of the second oil supplement valve 24 is in one-way communication with the left working oil port of the second main valve core 22, and the other end is connected with an oil return pipeline.

[0045] Specifically, the oil outlet Pb of the steering gear 7 inputs oil, the oil pressure changes the valve core position of the second pilot valve core 21 to perform steering; when the oil enters the second main valve core 22, the pressure acts on the control end to control the steering of the second main valve core 22; the oil flows out of the second main valve core 22 and is output into the steering oil cylinder 6 through the second check valve 23 to perform right turning oil input. At the same time, the oil pressure acts on the spring cavity end of the second main valve core 22 through the second pilot valve core 21, and then the opening of the steering of the second main valve core 22 depends on the size of the flow of the oil outlet Pb of the steering gear 7.​

[0046] In the embodiment, a first overload valve 15 and a second overload valve 25 are further included; one end of the first overload valve 15 is connected with the right working oil port of the first main valve core 12, and the other end is connected with an oil return pipeline; one end of the second overload valve 25 is connected with the left working oil port of the second main valve core 22, and the other end is connected with the oil return pipeline.

[0047] In the embodiment, a throttle hole 5 is arranged on each of the first pilot valve core 11 and the second pilot valve core 21.

[0048] In the embodiment, a priority valve 10 and a one-way throttle valve 3 connected with the priority valve 10 are further included; the steering pump 8 oil inlet port P of the priority valve 10 is connected with the oil tank 9 through a variable pump, the CF port is connected with the steering gear 7 oil inlet port, the EF port is connected with the working system multi-way valve oil inlet port, the LS port is connected with the steering gear 7 control port, and the T1 port is a safety valve oil return port.

[0049] In the embodiment, an overflow valve 4 is further included; the oil inlet end of the overflow valve 4 is communicated with the spring cavity of the priority valve 10, and the oil outlet port is communicated with the oil tank 9 through an oil return pipeline.

[0050] In the embodiment, the steering cylinder 6 switching away is as follows:

[0051] Left turn oil inlet: the first main valve core 12 is controlled by the first pilot valve core 11; when Pa oil is input, the first pilot valve core 11 works at the left position, the first main valve core 12 works at the right position, the first main valve core 12 switching displacement is generated by the pressure difference of the flow through the differential pressure control valve port of the first main valve core 12, the pressure before the flow through the first main valve core 12 acts on the right end (i.e. the control end) of the first main valve core 12, the pressure after the flow through the differential pressure control valve port of the first main valve core 12 acts on the left end (i.e. the spring cavity end) of the first main valve core 12 through the first pilot valve core 11, and the flow enters the steering cylinder 6 through the first one-way valve 13.

[0052] Right turn oil inlet: similarly, the second main valve core 22 is controlled by the second pilot valve core 21; when Pb oil is input, the second pilot valve core 21 works at the right position, the second main valve core 22 works at the left position, the second main valve core 22 switching displacement is generated by the pressure difference of the flow through the differential pressure control valve port of the second main valve core 22, the pressure before the flow through the second main valve core 22 acts on the left end (i.e. the control end) of the second main valve core 22, the pressure after the flow through the differential pressure control valve port of the second main valve core 22 acts on the left end (i.e. the spring cavity end) of the second main valve core 22 through the second pilot valve core 21, and the flow enters the steering cylinder 6 through the second one-way valve 23.

[0053] The priority valve 10 core is used for realizing constant pressure difference compensation control, that is, one priority valve 10 core is used for realizing pressure compensation control of two reversing valve cores (the first main valve core 12 and the second main valve core 22).

[0054] The first main valve core 12 and the second main valve core 22 independently control the reversing of the steering oil cylinder 6, that is, when the first main valve core 12 is filled with oil, the left turning of the steering oil cylinder 6 is controlled, and when the second main valve core 22 is filled with oil, the right turning of the steering oil cylinder 6 is controlled.

[0055] The utility model embodiment further provides a kind of hydraulic system, referring to Figure 2 , including steering oil cylinder 6 and sequentially connected steering gear 7, steering pump 8, oil tank 9 and the steering valve described above, the right working oil port of the first main valve core 12 in the steering valve, the left working oil port of the second main valve core 22 are connected with the large cavity / small cavity and small cavity / large cavity of steering oil cylinder 6 respectively, and the oil return port of the first main valve core 12 and the second main valve core 22 is communicated with oil tank 9.

[0056] Taking the time-sharing control of the first steering control module executing left turning oil and the second steering control module executing right turning oil as an example, the connection mode of the steering gear 7 and the steering oil cylinder 6 is as shown in Figure 2 , in other embodiments, if left turning oil and right turning oil need to be controlled simultaneously, the connection mode of the steering gear 7 and the steering oil cylinder 6 can be designed according to requirements, and the embodiment is not limited. Referring to Figure 2 、 Figure 3 The EF port of the priority valve 10 is connected with the multi-way valve oil inlet of working system (such as the oil inlet P of distribution valve in Figure 3 ).

[0057] The utility model embodiment further provides a kind of wheeled walking equipment, including the hydraulic system described above, and the walking equipment includes but is not limited to loader, mine machinery, heavy truck, large forklift, agricultural machinery.

[0058] The utility model has the following beneficial effects:

[0059] (1) For bidirectional control of the steering oil cylinder 6, a first steering control module and a second steering control module are provided independently of each other, and a one-to-one first pilot valve core 11 and a first main valve core 12 and a second pilot valve core 21 and a second main valve core 22 are used, in the left / right oil inlet process of the steering oil cylinder 6, the first main valve core 12 and the second main valve core 22 can work independently and respectively control the oil flow entering the left and right cavities of the steering oil cylinder 6, without switching the control pilot valve core when switching left and right, thereby effectively improving the response speed and control accuracy; at the same time, the two independent steering control modules can flexibly change the flow direction, pressure and flow supply size of the oil according to the needs, to adapt to the complex and variable working condition requirements.

[0060] (2) A one-way valve (first one-way valve 13, second one-way valve 23) is arranged between the oil outlet of the main valve core (first main valve core 12, second main valve core 22) and the pilot valve core (first pilot valve core 11, second pilot valve core 21), to limit the reverse flow of oil, effectively prevent the high-pressure oil at the oil outlet from being backflushed to the pilot valve core control cavity during the rapid switching action of the main valve core, avoid pressure impact, and enhance system stability.

[0061] (3) The oil outlet of the main valve core (first main valve core 12, second main valve core 22) is connected to an oil supplementing one-way valve (first oil supplementing valve 14, second oil supplementing valve 24), the oil in the return pipeline is supplemented to the oil outlet of the main valve core in time, so as to maintain pressure stability and flow balance, and avoid system fluctuation affecting response efficiency.

[0062] (4) An overload valve (first overload valve 15 and second overload valve 25) is connected to the oil outlet of the main valve core (first main valve core 12, second main valve core 22), and a return port is added to the hydraulic cylinder, when the load is overloaded, the overload valve will automatically open, so that the hydraulic oil enters the steering oil cylinder 6, thereby slowing down the descending speed of the load and keeping the load running smoothly.

[0063] (5) An overflow valve 4 connected with the priority valve 10 is arranged, on the one hand, when the steering gear 7 is working, the hydraulic oil based on the priority valve 10 will be preferentially supplied to the steering system, to ensure the flexibility and accuracy of steering; on the other hand, the overflow valve 4 can control the flow size by adjusting the valve core lift or spring pre-tightening force, the flow stability is good, the pressure control is accurate, and different flow and pressure requirements of the hydraulic system can be met.

[0064] The above embodiments are the preferred embodiments of the present application, but the embodiments of the present application are not limited by the above embodiments, any changes, modifications, substitutions, combinations and simplifications made without departing from the spirit and principles of the present application shall be equivalent replacement modes, and all are included in the protection scope of the present application.

Claims

1. A diverter valve characterized by: The first steering control module and the second steering control module are connected with the diverter, and the first steering control module and the second steering control module are respectively connected with two ends of the steering oil cylinder; The first steering control module comprises a first pilot valve core and a first main valve core; an oil inlet of the first main valve core is connected with an oil outlet of the first pilot valve core, and an oil outlet of the first main valve core is connected with one end of the steering oil cylinder; The second steering control module comprises a second pilot valve core and a second main valve core; an oil inlet of the second main valve core is connected with an oil outlet of the second pilot valve core, and an oil outlet of the second main valve core is connected with the other end of the steering oil cylinder.

2. A diverter valve as claimed in claim 1, characterised in that: The first pilot valve core comprises a two-position four-way directional valve, an oil inlet P of the two-position four-way directional valve is connected with the diverter, oil outlets A and B are connected with the first main valve core, and the oil outlet of the first main valve core is connected with one end of the steering oil cylinder.

3. A diverter valve as claimed in claim 2, characterised in that: The first main valve core comprises a two-position six-way directional valve, and the two-position six-way directional valve is in a right position in a normal state, so that a working oil inlet is communicated with a right working oil outlet, and a left working oil outlet is communicated with an oil return port; Oil liquid is input from an oil outlet of the diverter, and a valve core position of the first pilot valve core is changed by oil liquid pressure to perform direction changing; when oil liquid enters the first main valve core, pressure acts on a control end of the first main valve core to control the first main valve core to change direction, so as to perform left-turn oil inlet.

4. A diverter valve as claimed in claim 1, characterised in that: The second pilot valve core comprises a two-position four-way directional valve, an oil inlet P of the two-position four-way directional valve is connected with the diverter, oil outlets A and B are connected with the second main valve core, and an oil outlet of the second main valve core is connected with the other end of the steering oil cylinder.

5. A diverter valve as claimed in claim 4, characterised in that: The second main valve core comprises a two-position six-way directional valve, and the two-position six-way directional valve is in a left position in a normal state, so that a working oil inlet is communicated with a left working oil outlet, and a right working oil outlet is communicated with an oil return port; Oil liquid is input from an oil outlet of the diverter, and a valve core position of the second pilot valve core is changed by oil liquid pressure to perform direction changing; when oil liquid enters the second main valve core, pressure acts on a control end of the second main valve core to control the second main valve core to change direction, so as to perform right-turn oil inlet.

6. A diverter valve as claimed in claim 1, characterised in that: The priority valve and a one-way throttling valve connected with the priority valve are further included, an oil inlet P of the priority valve is connected with an oil tank through a variable pump, a CF port is connected with an oil inlet of the diverter, an EF port is connected with an oil inlet of a multi-way valve of a working system, an LS port is connected with a control port of the diverter, and a T1 port is a safety valve oil return port.

7. A diverter valve as claimed in claim 3, characterised in that: The first protection module connected with the first steering control module is further included, the first protection module comprises a first one-way valve and a first oil supplement valve; an oil outlet A of the first pilot valve core is unidirectionally communicated with a left working oil outlet of the first main valve core through the first one-way valve; one end of the first oil supplement valve is unidirectionally communicated with the left working oil outlet of the first main valve core, and the other end is connected with an oil return pipeline; After oil liquid flows out from the first main valve core, the oil liquid is output into the steering oil cylinder through the first one-way valve; meanwhile, oil liquid pressure acts on a spring cavity end of the first main valve core through the first pilot valve core, so that the opening degree of the first main valve core to change direction depends on the size of the flow of the oil outlet of the diverter.

8. A diverter valve as claimed in claim 4, characterised in that: The second protection module is connected with the second steering control module, and includes a second one-way valve and a second oil supplement valve. After the oil flows out of the second main valve core, the oil is output into the steering oil cylinder through the second one-way valve. Meanwhile, the oil pressure acts on the spring cavity end of the second main valve core through the second pilot valve core, and the opening of the second main valve core is determined by the size of the flow rate of the steering oil cylinder.

9. A diverter valve as claimed in claim 6, characterised in that: The overflow valve is connected with the spring cavity of the priority valve, and the oil outlet is connected with the oil tank through the oil return pipeline.

10. A diverter valve as claimed in claim 1, characterised in that: The first overload valve and the second overload valve are further included. One end of the first overload valve is connected with the right working oil port of the first main valve core, and the other end is connected with the oil return pipeline. One end of the second overload valve is connected with the left working oil port of the second main valve core, and the other end is connected with the oil return pipeline.

11. A hydraulic system comprising a steering cylinder and a steering gear, a steering pump and a tank connected in series, characterized in that, The right working oil port of the first main valve core and the left working oil port of the second main valve core are respectively connected with the large cavity / small cavity and the small cavity / large cavity of the steering oil cylinder, and the oil return ports of the first main valve core and the second main valve core are connected with the oil tank.

12. A walking apparatus characterized by comprising: The hydraulic system includes the steering valve.

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