CN212868105U - Electro-hydraulic control walking system - Google Patents

Abstract

The utility model relates to an engineering vehicle technical field specifically discloses an electricity accuse traveling system, including first main oil way, first guide's oil circuit, the gear solenoid valve, gear guide's hydro-cylinder, shift valve and a plurality of gear clutch, gear guide's hydro-cylinder includes first pole chamber, first no pole chamber and first piston rod, the gear solenoid valve can communicate first guide's oil circuit and first one in having pole chamber and first no pole chamber, and lead to another in oil tank and first pole chamber and the first no pole chamber, first piston rod is connected with the first case of shift valve, first case removes and enables the shift valve and with first main oil way and a plurality of gear clutch alternative intercommunication, with the switching of realization gear.

Description

Electro-hydraulic control walking system

Technical Field

The utility model relates to an engineering vehicle technical field especially relates to an electricity accuse traveling system.

Background

The crawler dozer has a severe working environment and has higher and higher requirements on the working reliability, the operation comfort and the like of products. Meanwhile, the control system of the bulldozer gradually approaches the industries of excavators and automobiles; the design of the control handle is more in line with the principle of ergonomics, the control is completely controlled by hydraulic pilot control or electrohydraulic control, the control force and the stroke are reduced, and a more comfortable and safe operation environment is provided for a user.

Bulldozers are classified into mechanical transmission, hydraulic mechanical transmission and hydraulic transmission according to the transmission mode. In a rational view, the bulldozers with the three transmission modes have different advantages. In contrast, customers prefer two types of products, namely hydraulic transmission and hydraulic transmission, and the hydraulic transmission and hydraulic transmission have high working efficiency and operation comfort. The hydraulic bulldozer still mainly operates the speed change valve and the steering valve by a mechanical connecting rod structure, and has the disadvantages of complex installation and debugging, complex operation, large operation force and low intelligent degree. The hydraulic transmission bulldozer can realize the functions of stepless speed change and left-right steering of the bulldozer by controlling the left-right traveling pump and the left-right traveling motor through the electric control single handle, and the electric control pilot control can overcome the defects existing in mechanical connecting rod operation. However, the electric control speed change valve has high requirement on the cleanliness of oil liquid, and is difficult to realize a pressure curve required by the power gear shifting gearbox, so that the problems of high system cost, high use cost and the like exist.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a: the electro-hydraulic control traveling system is provided to solve the problems that a bulldozer in the related art is controlled by an electric control speed change valve, the requirement on the cleanliness of oil is high, and the system cost and the use cost are high.

The utility model provides an electricity accuse traveling system, this electricity accuse traveling system include first main oil circuit, first guide's oil circuit, gear solenoid valve, gear guide's hydro-cylinder, shift valve and a plurality of gear clutch, the shift valve includes the first case, gear guide's hydro-cylinder includes first pole chamber and first no pole chamber to and first piston rod, first piston rod with first case is connected;

the gear electromagnetic valve can communicate the first pilot oil path with one of the first rod cavity and the first non-rod cavity, and the gear electromagnetic valve can communicate an oil tank with the other of the first rod cavity and the first non-rod cavity;

the first piston rod can drive the first valve core to move by stretching and contracting, so that the gear shifting valve enables the first main oil path and the gear clutches to be alternatively communicated.

As a preferred technical scheme of the electro-hydraulic control traveling system, the electro-hydraulic control traveling system further comprises a direction solenoid valve, a direction pilot oil cylinder, a forward clutch, a reversing valve and a backward clutch, wherein the reversing valve comprises a second valve core, the direction pilot oil cylinder comprises a second rod cavity, a second rodless cavity and a second piston rod, and the second piston rod is connected with the second valve core;

the directional solenoid valve can communicate the first pilot oil path with one of the second rod-containing cavity and the second rodless cavity, and the directional solenoid valve can communicate the oil tank with the other of the second rod-containing cavity and the second rodless cavity, so that the second piston rod can extend and retract;

the second piston rod can drive the second valve spool to move by stretching and contracting, so that the reversing valve enables the first main oil path to be communicated with one of the forward clutch and the backward clutch, or the reversing valve enables the first main oil path to be disconnected from and communicated with both the forward clutch and the backward clutch.

As a preferred technical scheme of the electro-hydraulic control traveling system, the electro-hydraulic control traveling system further comprises a neutral position lock-up solenoid valve, the direction solenoid valve is communicated with the second rod cavity through a first oil path, the direction solenoid valve is communicated with the second rodless cavity through a second oil path, the neutral position lock-up solenoid valve can communicate or disconnect the first oil path and the second oil path, and when the neutral position lock-up solenoid valve communicates the first oil path with the second oil path, the reversing valve communicates the first main oil path with one of the forward clutch and the backward clutch; when the neutral position lock-up electromagnetic valve disconnects the first oil path and the second oil path, the reversing valve disconnects and communicates the first main oil path with both the forward clutch and the reverse clutch.

As a preferred technical scheme of the electro-hydraulic control traveling system, the gear electromagnetic valve is communicated with the first rod cavity through an oil path A, the gear electromagnetic valve is communicated with the first rodless cavity through an oil path B, and the electro-hydraulic control traveling system further comprises four one-way damping valves respectively arranged on the first oil path, the second oil path, the oil path A and the oil path B.

As a preferred technical solution of the electro-hydraulic control traveling system, the number of the gear clutches is three, the gear solenoid valve has a left position, a right position and a middle position, when the gear solenoid valve is located at the left position, the gear solenoid valve communicates the first pilot oil path with the first rod chamber, when the gear solenoid valve is located at the right position, the gear solenoid valve communicates the first pilot oil path with the first non-rod chamber, and when the gear solenoid valve is located at the middle position, the gear solenoid valve simultaneously communicates the first pilot oil path with the first rod chamber and the first non-rod chamber.

As a preferable technical scheme of the electro-hydraulic control traveling system, the electro-hydraulic control traveling system further comprises a variable speed pump and a first oil filter connected with the variable speed pump, and the first oil filter is respectively communicated with the first main oil path and the first pilot oil path.

As a preferred technical scheme of the electro-hydraulic control traveling system, the electro-hydraulic control traveling system further comprises a second main oil path, a left steering valve, a left brake valve, a left steering clutch and a left brake clutch, wherein the left steering valve can enable an oil inlet of the left steering clutch to be communicated with the second main oil path and the oil tank alternatively, and the left brake valve can enable an oil inlet of the left brake clutch to be communicated with the second main oil path and the oil tank alternatively;

the electro-hydraulic control traveling system further comprises a right steering valve, a right brake valve, a right steering clutch and a right brake clutch, wherein the right steering valve can enable an oil inlet of the right steering clutch to be communicated with the second main oil path and the oil tank alternatively, and the right brake valve can enable an oil inlet of the right brake clutch to be communicated with the second main oil path and the oil tank alternatively.

As a preferred technical scheme of the electro-hydraulic control traveling system, the electro-hydraulic control traveling system further includes an operating handle and a second pilot oil path, the second pilot oil path is simultaneously connected with the left steering valve and the left brake valve through a first branch, the second pilot oil path is simultaneously connected with the right steering valve and the right brake valve through a second branch, the operating handle is used for adjusting first pilot pressure of the first branch acting on the left steering valve and the left brake valve, and the operating handle is used for adjusting second pilot pressure of the second branch acting on the right steering valve and the right brake valve.

As a preferable technical scheme of the electro-hydraulic control traveling system, the electro-hydraulic control traveling system further comprises a steering pump and a second oil filter, the steering pump is connected with the second oil filter, and the second oil filter is respectively connected with the second main oil path and the second pilot oil path.

As a preferred technical scheme of the electro-hydraulic control travelling system, the electro-hydraulic control travelling system further comprises a steering overflow valve connected with the second oil filter, and an oil cooler and a steering safety overflow valve which are both connected with the steering overflow valve, wherein the oil cooler and the steering safety overflow valve are both connected with the oil tank.

The utility model has the advantages that:

the utility model provides an electricity liquid accuse running system, this electricity liquid accuse running system include first main oil circuit, first guide's oil circuit, gear solenoid valve, gear guide's hydro-cylinder, shift valve and a plurality of gear clutch. The gear pilot oil cylinder comprises a first rod cavity, a first rodless cavity and a first piston rod, the gear electromagnetic valve can be communicated with the first pilot oil way and one of the first rod cavity and the first rodless cavity, and the gear electromagnetic valve can be communicated with the oil tank and the other of the first rod cavity and the first rodless cavity. The gear shifting valve comprises a first valve core, a first piston rod is connected with the first valve core, so that the first valve core can be driven to move by the expansion and contraction of the first piston rod, and the first valve core can enable the gear shifting valve to select and communicate a first main oil way and a plurality of gear clutches through movement so as to realize gear switching. The electro-hydraulic control traveling system is matched with the gear pilot oil cylinder through the gear electromagnetic valve, is controlled by electro-hydraulic combination, and adopts a mechanical pressure regulating structure, so that the requirement on the cleanliness of oil can be effectively reduced, and the cost of engineering machinery is reduced.

Drawings

Fig. 1 is a part of a schematic structural diagram of an electro-hydraulic control walking system in an embodiment of the present invention;

fig. 2 is another part of the schematic structural diagram of the electric hydraulic control walking system in the embodiment of the present invention.

In the figure:

1. a first main oil passage; 2. a first pilot oil passage; 3. a gear electromagnetic valve; 4. a gear pilot oil cylinder; 5. a shift valve; 6. a gear clutch; 7. a controller; 8. an operating handle; 9. a direction solenoid valve; 10. a direction pilot oil cylinder; 11. a diverter valve; 12. a forward clutch; 13. a reverse clutch; 14. a forward gear pressure sensor; 15. a reverse gear pressure sensor; 16. a first oil passage; 17. a second oil passage; 18. an oil path A; 19. an oil passage B; 20. a neutral gear vehicle locking electromagnetic valve; 21. a one-way damping valve; 22. a variable speed pump; 23. a first oil filter; 24. an accumulator assembly; 25. a pressure regulating valve; 26. a quick return valve; 27. a second main oil passage; 28. a left steering valve; 29. a left brake valve; 30. a left steering clutch; 31. a left braking clutch; 32. a right steering valve; 33. a right brake valve; 34. a right steering clutch; 35. a right brake clutch; 36. a second pilot oil passage; 37. a steering pump; 38. a second oil filter; 39. a steering overflow valve; 40. an oil cooler; 41. a steering safety overflow valve; 42. a first branch; 43. a second branch circuit; 44. and an oil tank.

Detailed Description

The technical solution of the present invention will be described clearly and completely with reference to the accompanying drawings, and obviously, the described embodiments are some, but not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Where the terms "first position" and "second position" are two different positions, and where a first feature is "over", "above" and "on" a second feature, it is intended that the first feature is directly over and obliquely above the second feature, or simply means that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted", "connected" and "connected" are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrally connected; mechanical connection and electrical connection can be realized; they may be connected directly or indirectly through intervening media, allowing communication between the two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

As shown in fig. 1 and fig. 2, the embodiment provides an electro-hydraulic traveling system, which can be applied to a bulldozer, a forklift and other engineering machinery. The electro-hydraulic control traveling system comprises a first main oil path 1, a first pilot oil path 2, a gear electromagnetic valve 3, a gear pilot oil cylinder 4, a gear shifting valve 5 and a plurality of gear clutches 6. The gear pilot oil cylinder 4 comprises a first rod cavity, a first rodless cavity and a first piston rod. Specifically, the gear pilot oil cylinder 4 has a first piston cavity, a first piston rod is slidably located in the first piston cavity, and divides the first piston cavity into a first rod cavity and a first non-rod cavity which are not communicated with each other and have variable volumes, the gear electromagnetic valve 3 can communicate the first pilot oil path 2 with one of the first rod cavity and the first non-rod cavity, and the gear electromagnetic valve 3 can communicate the oil tank 44 with the other of the first rod cavity and the first non-rod cavity. When the gear solenoid valve 3 communicates the first pilot oil path 2 and the first rod chamber, the first rod chamber communicates with the oil tank 44, the first piston rod retracts, when the gear solenoid valve 3 communicates the first pilot oil path 2 and the first rod chamber, the first rod chamber communicates with the oil tank 44, and the first piston rod extends. The gear shifting valve 5 comprises a first valve core, a first piston rod is connected with the first valve core, so that the first valve core can be driven to move by the expansion and contraction of the first piston rod, and the first valve core can enable the gear shifting valve 5 to select and communicate the first main oil way 1 and the gear clutches 6 so as to realize the switching of gears. In the embodiment, the gear electromagnetic valve 3 is matched with the gear pilot oil cylinder 4, the electro-hydraulic combination is adopted for control, and a mechanical pressure regulating structure is adopted, so that the requirement on the cleanliness of oil can be effectively reduced, and the cost of engineering machinery is reduced.

In this embodiment, the number of the gear clutches 6 is three, and the three gear clutches 6 are a first gear clutch, a second gear clutch, and a third gear clutch, respectively. The gear solenoid valve 3 has a left position, a right position and a middle position, specifically, when the gear solenoid valve 3 is located at the left position, the gear solenoid valve 3 communicates the first pilot oil path 2 with the first rod chamber and communicates the first non-rod chamber and the oil tank 44, and the shift valve 5 communicates the first main oil path 1 and the first gear clutch; when the gear electromagnetic valve 3 is positioned at the right position, the gear electromagnetic valve 3 is communicated with the first pilot oil way 2 and the first non-rod cavity and is communicated with the first rod cavity and the oil tank 44, and the gear shifting valve 5 is communicated with the first main oil way 1 and the third gear clutch; when the gear solenoid valve 3 is located at the neutral position, the gear solenoid valve 3 makes the first pilot oil path 2 communicate with the first rod chamber and the first non-rod chamber simultaneously, the first rod chamber and the first non-rod chamber are disconnected from the oil tank 44 simultaneously, and the shift valve 5 communicates the first main oil path 1 and the second gear clutch. Therefore, the gear electromagnetic valve 3 is controlled to be switched among the left position, the right position and the middle position, and the switching among three gears can be realized. The range solenoid valve 3 is preferably a three-position, four-way valve solenoid valve having two solenoid controlled terminals. In other embodiments, the gear clutch 6 may be provided in two as needed, and the gear solenoid valve 3 may be a two-position four-way solenoid valve accordingly.

In this embodiment, the electro-hydraulic control walking system further includes a controller 7 and an operating handle 8, and the operating handle 8 is provided with an upshift/downshift button. The gear-up button and the gear-down button are both connected with the controller 7, the controller 7 is connected with two electromagnetic control ends of the gear electromagnetic valve 3, the gear-up button or the gear-down button is pressed each time, the controller 7 can switch the state of the gear electromagnetic valve 3 by controlling the two electromagnetic control ends of the gear electromagnetic valve 3 to be powered on or powered off, so that the gear electromagnetic valve 3 is switched among a left position, a right position and a middle position, and then the first piston rod drives the first valve core to move, so that the first main oil way 1 is switched with the gear clutch 6 communicated with the first main oil way, and the gear-shifting operation is realized.

Optionally, the electro-hydraulic control traveling system further comprises a direction solenoid valve 9, a direction pilot cylinder 10, a reversing valve 11, a forward clutch 12 and a backward clutch 13, wherein the direction pilot cylinder 10 comprises a second rod cavity, a second rodless cavity and a second piston rod; the directional solenoid valve 9 can communicate the first pilot oil path 2 with one of the second rod-containing chamber and the second rodless chamber, and the directional solenoid valve 9 can communicate the oil tank 44 with the other of the second rod-containing chamber and the second rodless chamber, so that the second piston rod can extend and retract; the reversing valve 11 comprises a second valve core, a second piston rod is connected with the second valve core, the second piston rod can drive the second valve core to move in a stretching mode, and then the first main oil path 1 can be communicated with the forward clutch 12 and the backward clutch 13 through the reversing valve 11, or the first main oil path 1 can be disconnected from the forward clutch 12 and the backward clutch 13 through the reversing valve 11. Therefore, reversing control of the electro-hydraulic control traveling system also adopts an electro-hydraulic combination mode, so that the requirement on the cleanliness of oil can be further reduced, and the cost of engineering machinery is reduced.

Specifically, in this embodiment, the directional solenoid valve 9 may be a three-position four-way solenoid valve. The directional solenoid valve 9 also has two electromagnetic control ends, the two electromagnetic control ends of the directional solenoid valve 9 are respectively connected with the controller 7, and the controller 7 can switch the state of the directional solenoid valve 9 by controlling the two electromagnetic control ends of the directional solenoid valve 9 to be powered on or powered off. The operating handle 8 can rotate in the front-back direction at the initial middle position, and when the operating handle 8 rotates forwards from the initial middle position to a first set position, the controller 7 controls the direction solenoid valve 9 to communicate the first pilot oil path 2 with the second rod chamber, and communicate the oil tank 44 with the second rodless chamber, so that the second piston rod moves to the left, and simultaneously the second piston rod drives the second valve core to move to the left, and the reversing valve 11 communicates the second oil path 17 with the forward clutch 12; similarly, when the operating handle 8 rotates backwards from the initial middle position to the second set position, the controller 7 controls the direction solenoid valve 9 to communicate the first pilot oil path 2 with the second rodless cavity, and communicate the oil tank 44 with the second rod cavity, so that the second piston rod moves rightwards, meanwhile, the second piston rod drives the second valve spool to move rightwards, and the reversing valve 11 communicates the second oil path 17 with the backward clutch 13, so that the switching of the vehicle running direction can be realized. When the operating handle 8 is located between the first set position and the second set position, the controller 7 controls the directional solenoid valve 9 to simultaneously connect the first pilot oil passage 2 to the second rodless chamber and the second rod chamber, simultaneously disconnect the oil tank 44 from the second rodless chamber and the second rod chamber, and maintain the second piston rod at the initial intermediate position, at which time the direction change valve 11 simultaneously disconnects the second oil passage 17 from the forward clutch 12 and the reverse clutch 13, and the transmission is in the neutral position. So that the forward direction of the vehicle can be switched by operating the handle 8.

Specifically, in this embodiment, the operating handle 8 is a hydraulic operating handle, the operating handle 8 is supplied with oil from an oil supply pump, the operating handle 8 has first pressure output ports in the front-rear direction, and the oil pressure of the first pressure output ports on the front side and the rear side can be adjusted by rotating the operating handle 8 in the front-rear direction. The first pressure output ports on the front side and the rear side are communicated with the oil tank 44, the first pressure output ports on the front side and the rear side are respectively provided with a forward gear pressure sensor 14 and a backward gear pressure sensor 15, the forward gear pressure sensor 14 and the backward gear pressure sensor 15 are connected with the controller 7, the controller 7 collects the pressures of the forward gear pressure sensor 14 and the backward gear pressure sensor 15 and calculates the pressure difference between the two, and when the pressure difference reaches the set pressure, the controller 7 controls the direction electromagnetic valve 9 to switch among three states and execute reversing. It is understood that when the control operating handle 8 is rotated to the first set position or the second set position, the absolute value of the pressure difference between the forward gear position pressure sensor 14 and the reverse gear position pressure sensor 15 each just reaches the set pressure. In this embodiment, the set pressure is set to 13bar, and in other embodiments, the pressure difference may be set as needed. Preferably, the electro-hydraulic control walking system further comprises two blocking structures, and when the operating handle 8 moves forwards from the initial middle position to the first set position, or when the operating handle 8 moves backwards from the initial middle position to the second set position, the two blocking structures can limit the operating handle 8 to move forwards or backwards respectively.

As an alternative scheme, two sides of the operating handle 8 in the front-rear direction are respectively provided with a position sensor, the two position sensors are respectively connected with the controller 7, when the operating handle 8 moves to a first set position and a second set position, the corresponding position sensors can be triggered, and then the controller 7 controls the direction electromagnetic valve 9 to switch states and execute reversing.

Optionally, the electro-hydraulic control traveling system further includes a neutral lock solenoid valve 20, the direction solenoid valve 9 is communicated with the second rod chamber through the first oil path 16, the direction solenoid valve 9 is communicated with the second rodless chamber through the second oil path 17, the neutral lock solenoid valve 20 can communicate or disconnect the first oil path 16 and the second oil path 17, and when the neutral lock solenoid valve 20 communicates the first oil path 16 with the second oil path 17, the reversing valve 11 selectively communicates the first main oil path 1 with the forward clutch 12 and the reverse clutch 13; when the neutral lock solenoid valve 20 disconnects the first oil passage 16 and the second oil passage 17, the selector valve 11 disconnects the first main oil passage 1 from both the forward clutch 12 and the reverse clutch 13. Specifically, the neutral lock solenoid valve 20 is a two-position two-way solenoid valve, and is connected to the controller 7, in an initial state, an electromagnetic control end of the neutral lock solenoid valve 20 is in an energized state, the first oil path 16 is communicated with the second oil path 17, oil pressures in the second rod chamber and the second rod-free chamber are consistent at the time, the second piston rod is in an initial intermediate position, and the second valve core disconnects the second oil path 17 from the forward clutch 12 and the reverse clutch 13 at the same time, so that a neutral position is maintained, and neutral lock is achieved, so as to ensure driving safety. The controller 7 may control the solenoid control terminal of the neutral lock solenoid valve 20 to be energized to disconnect the first oil passage 16 and the second oil passage 17, at which time a shift operation may be performed. A neutral position vehicle locking key can be arranged and connected with the controller 7, and a driver can press the neutral position vehicle locking key to enable the controller 7 to control the neutral position vehicle locking electromagnetic valve 20 to lose power.

In this embodiment, when starting the vehicle, if the driver selects the forward direction, the controller 7 may control the initial position of the gear electromagnetic valve 3 to be located at the left position or the middle position, and accordingly, the forward gear when starting the vehicle may correspond to the forward 1 gear or the forward 2 gear; if the driver selects the reverse direction, the controller 7 may control the initial position of the gear electromagnetic valve 3 to be located at the left position or the middle position, and accordingly, the reverse gear during starting may correspond to the reverse 1-gear or the reverse 2-gear, so that three different starting states of F1/R1, F1/R2 and F2/R2 may be combined during starting, where F1 is the forward 1-gear, F2 is the forward 2-gear, R1 is the reverse first-gear, and R2 is the reverse second-gear. Preferably, the driver can set the three starting states autonomously according to actual working condition requirements. For example, three selection buttons may be provided on the operation panel, the three selection buttons are connected to the controller 7, and the three selection buttons correspond to the three different start states one by one.

Optionally, the gear solenoid valve 3 and the first rod chamber and the first non-rod chamber are respectively communicated through an oil path a18 and an oil path B19, and the electro-hydraulic control traveling system further includes four one-way damping valves 21 respectively disposed on the first oil path 16, the second oil path 17, the oil path a18 and the oil path B19. The check damper valve 21 includes a check valve and a damper valve connected in parallel, and the check valve is configured to allow only the oil to flow from the first pilot oil passage 2 to the direction pilot cylinder 10 or the range pilot cylinder 4. The one-way damping valve 21 is arranged to control the moving speed of a piston rod of the pilot oil cylinder, and hydraulic impact force on the first valve core and the second valve core in the power shifting/reversing process is optimized.

Optionally, the electro-hydraulic traveling system further includes a transmission pump 22 and a first oil filter 23 connected to the transmission pump 22, and the first oil filter 23 is communicated with the first main oil passage 1 and the first pilot oil passage 2, respectively. Preferably, the electro-hydraulic walking system further comprises an accumulator assembly 24, and the accumulator assembly 24 is arranged on the first pilot oil path 2. The oil pressure of the first pilot oil passage 2 can be ensured to be stable by providing the accumulator assembly 24. And when the neutral lock-up vehicle is in a flameout state, the energy accumulator assembly 24 can also ensure that the second rod cavity and the second rodless cavity in the direction guide oil cylinder 10 have enough oil pressure to keep the position of the second piston stable, thereby ensuring the neutral lock-up vehicle effect.

When the gear solenoid valve 3 is operated to shift gears, but the pressure of the first main oil path 1 is high, the piston of the gear clutch 6 acts fast, and the gear clutch 6 is also engaged rapidly, which may cause sudden start of the vehicle and severe vibration of the vehicle. In order to avoid the phenomenon, the first main oil path 1 is provided with a pressure regulating valve 25 and a quick return valve 26, an oil outlet of the pressure regulating valve 25 is connected with an oil inlet of the quick return valve 26, and an oil outlet of the quick return valve 26 is connected with the gear shifting valve 5.

Optionally, the electro-hydraulic control traveling system further comprises a second main oil path 27, a left steering valve 28, a left brake valve 29, a left steering clutch 30 and a left brake clutch 31, the left steering valve 28 enables an oil inlet of the left steering clutch 30 to be alternatively communicated with the second main oil path 27 and the oil tank 44, and the left brake valve 29 enables an oil inlet of the left brake clutch 31 to be alternatively communicated with the second main oil path 27 and the oil tank 44; during left steering operation, the left steering valve 28 firstly connects the second main oil path 27 with the oil inlet of the left steering clutch 30, so that large turning of the vehicle to the left can be realized, and then the left brake valve 29 connects the second main oil path 27 with the left brake clutch 31, so that small turning of the vehicle to the left can be realized.

The electro-hydraulic control traveling system further comprises a right steering valve 32, a right brake valve 33, a right steering clutch 34 and a right brake clutch 35, wherein the right steering valve 32 enables an oil inlet of the right steering clutch 34 to be communicated with one of the second main oil path 27 and the oil tank 44, and the right brake valve 33 enables an oil inlet of the right brake clutch 35 to be communicated with one of the second main oil path 27 and the oil tank 44. In the right steering operation, the right steering valve 32 firstly communicates the second main oil path 27 with an oil inlet of the right steering clutch 34, so that the vehicle can make a large turn right, and then the right brake valve 33 communicates the second main oil path 27 with the right brake clutch 35, so that the vehicle can make a small turn right.

Optionally, the electro-hydraulic traveling system further includes a second pilot oil path 36, the second pilot oil path 36 is simultaneously connected to the left steering valve 28 and the left brake valve 29 through a first branch 42, the second pilot oil path 36 is simultaneously connected to the right steering valve 32 and the right brake valve 33 through a second branch 43, the operating handle 8 is used for adjusting a first pilot pressure of the first branch 42 acting on the left steering valve 28 and the left brake valve 29, and the operating handle 8 is used for adjusting a second pilot pressure of the second branch 43 acting on the right steering valve 32 and the right brake valve 33. Specifically, the left steering valve 28, the left brake valve 29, the right steering valve 32 and the right brake valve 33 are all two-position three-way valves, the first branch 42 is connected with the pilot control ends of the left steering valve 28 and the left brake valve 29 respectively, and the second branch 43 is connected with the pilot control ends of the right steering valve 32 and the right brake valve 33 respectively. In the initial state, the left steering valve 28 communicates the left steering clutch 30 with the oil tank 44, the left brake valve 29 communicates the left brake clutch 31 with the oil tank 44, the right steering valve 32 communicates the right steering clutch 34 with the oil tank 44, and the right brake valve 33 communicates the right brake clutch 35 with the oil tank 44. When the first pilot pressure reaches a first set pressure, the left steering valve 28 is opened, the pilot oil enters the left steering clutch 30 at the moment, the vehicle performs a large leftward turning action, when the first pilot pressure reaches a second set pressure, the left brake valve 29 is opened, the pilot oil simultaneously enters the left brake clutch 31 at the moment, and the vehicle performs a small leftward turning action at the moment, wherein the second set pressure is greater than the first set pressure. When the second pilot pressure reaches a third set pressure, the right steering valve 32 is opened, the pilot oil enters the right steering clutch 34 at the moment, the vehicle performs a large right-turning action, when the second pilot pressure reaches a fourth set pressure, the right brake valve 33 is opened, the pilot oil simultaneously enters the right brake clutch 35 at the moment, and the vehicle performs a small right-turning action at the moment, wherein the fourth set pressure is greater than the third set pressure. In this embodiment, the operating handle 8 further rotates along the left-right direction, the operating handle 8 has a second pressure output oil port in the left-right direction, the second pilot oil path 36 is connected to the oil inlet of the operating handle 8, the left second pressure output oil port is connected to the first branch 42, the right second pressure output oil port is connected to the second branch 43, and the oil pressure of the left and right second pressure output ports can be adjusted by rotating the operating handle 8 along the left-right direction. Taking the example of turning the operation handle 8 to the left from the initial intermediate position, the oil pressure of the second pressure output port on the left gradually rises as the operation handle 8 turns, and when the oil pressure rises to the first set pressure, the left steering valve 28 opens, and when the oil pressure continues to rise to the second set pressure, the left brake valve 29 opens. In the present embodiment, the first set pressure is 14bar and the second set pressure is 18bar, but in other embodiments, the first set pressure and the second set pressure may be set as needed.

Optionally, the electro-hydraulic walking system further comprises a steering pump 37 and a second oil filter 38, the steering pump 37 is connected with the second oil filter 38, and the second oil filter 38 is respectively connected with the second main oil passage 27 and the second pilot oil passage 36. The steering pump 37 drives the oil into the second oil filter 38, and after being filtered by the second oil filter 38, the oil enters the second main oil passage 27 and the second pilot oil passage 36.

Optionally, the electro-hydraulic control traveling system further comprises a steering overflow valve 39 connected with the second oil filter 38, an oil cooler 40 and a steering safety overflow valve 41 which are both connected with the steering overflow valve 39, and the oil cooler 40 and the steering safety overflow valve 41 are both connected with an oil tank 44. Excess oil is overflowed through the diverting overflow valve 39 and the oil cooler 40 and cooled. When the oil cooler 40 is abnormal, the system safety can be ensured through the steering safety overflow valve 41.

The working principle of the electro-hydraulic control walking system is as follows:

taking the example that when the forward gear is engaged and the vehicle is started, the controller 7 controls the initial position of the gear electromagnetic valve 3 to be positioned at the left position, and the corresponding forward starting gear is the forward 1 gear, when the vehicle is started, the driver rotates the operating handle 8 forward, when the operating handle 8 is mainly rotated to be in contact with the clamping structure, the operating handle 8 moves to the first set position, the pressure difference between the forward gear pressure sensor 14 and the backward gear pressure sensor 15 reaches the set pressure, the controller 7 controls the electromagnetic control end at the left side of the gear electromagnetic valve 3 to be powered on, the electromagnetic control end at the right side is powered off, the gear electromagnetic valve 3 is positioned at the left position, the gear electromagnetic valve 3 is communicated with the first pilot oil way 2 and the first rod-containing cavity and is communicated with the oil tank 44 and the first rod-free cavity, under the driving of the pilot oil, the first piston rod retracts, the first valve core is positioned at the left side, the gear shifting valve 5 is communicated with the, and when the vehicle is in a first gear, the controller 7 controls the left electromagnetic control end of the directional solenoid valve 9 to be electrified and the right electromagnetic control end to be deenergized, the directional solenoid valve 9 is communicated with the first pilot oil way 2 and the second rod cavity and is communicated with the oil tank 44 and the second rodless cavity, the second piston rod retracts, the second valve spool is positioned on the left side, the reversing valve 11 is communicated with the first main oil way 1 and the forward clutch 12, and the vehicle is in a forward state and starts to operate when the vehicle is in a forward first gear. On the basis, a driver can press a shift-up button to enable the controller 7 to control the gear electromagnetic valve 3 to be positioned at the middle position, and correspondingly, the gear shifting valve 5 is communicated with the second gear clutch and the first main oil way 1 to enable the forward first gear to be shifted up to the forward second gear; on the basis, a driver can enable the controller 7 to control the gear electromagnetic valve 3 to be positioned at the right position by pressing the gear-up button, correspondingly, the gear-shifting valve 5 is communicated with the third gear clutch and the first main oil path 1, and the second forward gear is increased to the third forward gear; or the driver can press the gear-reducing button to enable the controller 7 to control the gear electromagnetic valve 3 to be positioned at the left position, and correspondingly, the gear shifting valve 5 is communicated with the first gear clutch and the first main oil path 1 to enable the forward second gear to be reduced to the forward first gear.

Taking left steering as an example in the process of vehicle traveling, a driver rotates the operating handle 8 to the left, the first pilot pressure is gradually increased, when the first pilot pressure reaches 14bar, the left steering valve 28 is opened, at the moment, the pilot oil enters the left steering clutch 30, and the vehicle performs a large left steering action; as the operating handle 8 continues to rotate to the left, when the first pilot pressure reaches 18bar, the left brake valve 29 opens, at which time pilot oil simultaneously enters the left brake clutch 31, at which time the vehicle executes a small left-turn maneuver.

When the driver selects the neutral lock function, the controller 7 controls the neutral lock solenoid valve 20 to be de-energized. The neutral lock-up solenoid valve 20 communicates the first oil passage 16 and the second oil passage 17, at this time, the second rodless chamber communicates with the second rod chamber, the second piston is located at the middle position, and accordingly, the second main oil passage 27 is simultaneously disconnected from the reverse clutch 13 and the forward clutch 12 by the selector valve 11, thereby achieving the neutral lock-up function.

It is obvious that the above embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims (10)

1. The electro-hydraulic control walking system is characterized by comprising a first main oil way (1), a first pilot oil way (2), a gear electromagnetic valve (3), a gear pilot oil cylinder (4), a gear shifting valve (5) and a plurality of gear clutches (6), wherein the gear shifting valve (5) comprises a first valve core, the gear pilot oil cylinder (4) comprises a first rod cavity, a first non-rod cavity and a first piston rod, and the first piston rod is connected with the first valve core;

the gear solenoid valve (3) can communicate the first pilot oil path (2) with one of the first rod chamber and the first non-rod chamber, and the gear solenoid valve (3) can communicate an oil tank (44) with the other of the first rod chamber and the first non-rod chamber;

the first piston rod can drive the first valve core to move by stretching and contracting, so that the gear shifting valve (5) enables the first main oil path (1) and the gear clutches (6) to be communicated alternatively.

2. The electro-hydraulic control walking system according to claim 1, further comprising a direction solenoid valve (9), a direction pilot cylinder (10), a forward clutch (12), a reversing valve (11) and a reverse clutch (13), wherein the reversing valve (11) comprises a second spool, the direction pilot cylinder (10) comprises a second rod cavity and a second rodless cavity, and a second piston rod connected with the second spool;

the directional solenoid valve (9) can communicate the first pilot oil path (2) with one of the second rod chamber and the second rodless chamber, and the directional solenoid valve (9) can communicate the oil tank (44) with the other of the second rod chamber and the second rodless chamber to enable the second piston rod to extend and retract;

the second piston rod can drive the second valve spool to move in a telescopic mode, so that the reversing valve (11) enables the first main oil path (1) to be communicated with the forward clutch (12) or the reverse clutch (13) alternatively, or the reversing valve (11) enables the first main oil path (1) to be disconnected from the forward clutch (12) or the reverse clutch (13).

3. The electric hydraulic control running system according to claim 2, further comprising a neutral lock-up solenoid valve (20), wherein the direction solenoid valve (9) is communicated with the second rod chamber through a first oil path (16), the direction solenoid valve (9) is communicated with the second rodless chamber through a second oil path (17), the neutral lock-up solenoid valve (20) can communicate or disconnect the first oil path (16) and the second oil path (17), and when the neutral lock-up solenoid valve (20) communicates the first oil path (16) and the second oil path (17), the change-over valve (11) communicates the first main oil path (1) with one of the forward clutch (12) and the reverse clutch (13); when the neutral lock-up electromagnetic valve (20) disconnects the first oil path (16) and the second oil path (17), the reversing valve (11) disconnects the first main oil path (1) from both the forward clutch (12) and the reverse clutch (13).

4. The electro-hydraulic control walking system according to claim 3, wherein the gear electromagnetic valve (3) is communicated with the first rod cavity through an oil path A (18), the gear electromagnetic valve (3) is communicated with the first non-rod cavity through an oil path B (19), and the electro-hydraulic control walking system further comprises four one-way damping valves (21) which are respectively arranged on the first oil path (16), the second oil path (17), the oil path A (18) and the oil path B (19).

5. The electro-hydraulic control walking system of claim 1, wherein the number of the gear clutches (6) is three, the gear solenoid valve (3) has a left position, a right position and a middle position, when the gear solenoid valve (3) is located at the left position, the gear solenoid valve (3) communicates the first pilot oil path (2) with the first rod chamber, when the gear solenoid valve (3) is located at the right position, the gear solenoid valve (3) communicates the first pilot oil path (2) with the first non-rod chamber, and when the gear solenoid valve (3) is located at the middle position, the gear solenoid valve (3) communicates the first pilot oil path (2) with the first rod chamber and the first non-rod chamber simultaneously.

6. The electric hydraulic traveling system according to claim 1, further comprising a transmission pump (22) and a first oil filter (23) connected to the transmission pump (22), the first oil filter (23) being in communication with the first main oil passage (1) and the first pilot oil passage (2), respectively.

7. The electric hydraulic control traveling system according to any one of claims 1 to 6, further comprising a second main oil passage (27), a left steering valve (28), a left brake valve (29), a left steering clutch (30), and a left brake clutch (31), wherein the left steering valve (28) enables an oil inlet of the left steering clutch (30) to communicate with either the second main oil passage (27) or the oil tank (44), and the left brake valve (29) enables an oil inlet of the left brake clutch (31) to communicate with either the second main oil passage (27) or the oil tank (44);

the electro-hydraulic control walking system further comprises a right steering valve (32), a right brake valve (33), a right steering clutch (34) and a right brake clutch (35), wherein the right steering valve (32) can enable an oil inlet of the right steering clutch (34) to be communicated with the second main oil way (27) and the oil tank (44) alternatively, and the right brake valve (33) can enable an oil inlet of the right brake clutch (35) to be communicated with the second main oil way (27) and the oil tank (44) alternatively.

8. The electric hydraulic traveling system according to claim 7, further comprising an operating handle (8) and a second pilot oil passage (36), the second pilot oil passage (36) connecting the left steering valve (28) and the left brake valve (29) through a first branch (42), the second pilot oil passage (36) connecting the right steering valve (32) and the right brake valve (33) through a second branch (43), the operating handle (8) being configured to adjust a first pilot pressure applied to the left steering valve (28) and the left brake valve (29) by the first branch (42), and the operating handle (8) being configured to adjust a second pilot pressure applied to the right steering valve (32) and the right brake valve (33) by the second branch (43).

9. The electric hydraulic traveling system according to claim 8, further comprising a steering pump (37) and a second oil filter (38), the steering pump (37) being connected to the second oil filter (38), the second oil filter (38) being connected to the second main oil passage (27) and the second pilot oil passage (36), respectively.

10. The electric hydraulic walking system according to claim 9, further comprising a steering relief valve (39) connected to the second oil filter (38), and an oil cooler (40) and a steering relief valve (41) both connected to the steering relief valve (39), wherein the oil cooler (40) and the steering relief valve (41) both are connected to the oil tank (44).

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