Hydraulic control system and control method for chassis of cleaning and screening all-in-one machine

Abstract

The invention provides a hydraulic control system and method for a chassis of a cleaning and screening all-in-one machine. The system comprises a crawler hydraulic control unit, a rail wheel hydraulic control unit, a rail wheel lifting oil cylinder, a rail wheel floating pilot valve, a rail wheel walking switching valve, a rail wheel unlocking valve and a shuttle valve. The rail wheel hydraulic control unit comprises a hydraulic motor, a hydraulic motor control valve and a wheel rail brake; oil ports of the rail wheel walking switching valve and the oil cylinder control valve are connected in series, and the rail wheel walking switching valve and the oil cylinder control valve are used for switching high-pressure oil to the rail wheel hydraulic control unit or the track hydraulic control unit; the rail wheel floating pilot valve is connected with a third oil port of the shuttle valve and is also connected with a pilot oil port of the rail wheel floating hydraulic control valve; the rail wheel unlocking valve is connected with a second oil port of the shuttle valve, and a first oil port of the shuttle valve is connected with the wheel rail brake; when the rail wheel floating pilot valve is electrified, the wheel rail brake relieves braking on the hydraulic motor, and two oil ports of the hydraulic motor are communicated to enable the rail wheel driving device to float; according to the invention, different walking modes of the chassis can be effectively controlled.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering machinery hydraulics, and in particular to a hydraulic control system and a control method for a chassis of an integrated cleaning and screening machine. Background Art

[0002] Railway ballast cleaning and screening integrated, the travel drive under its mechanical system has two actions:

[0003] The first action: when walking on the ground, it uses a crawler drive device to drive the walking, which has a large driving force and low requirements on the road surface;

[0004] The second action: when working on the track, the rubber pads attached to the steel crawler track move on the guide rails, and the rail wheel lifting cylinder drops to make the rail wheel drive device fall and get stuck in the middle of the rail to play a guiding role; when the rail wheel lifting cylinder continues to drop, the crawler track is supported to leave the rail, and the rail wheel drive device is used to drive it to move on the rail.

[0005] For the first action, when the crawler is moving, the rail wheel needs to be lifted or positioned and guided, that is, the rail wheel needs to be in a floating state; for the second action, when the crawler is lifted and the rail wheel is driven, various working conditions of the wheel and rail need to be controlled to meet actual needs.

[0006] Therefore, there is an urgent need for a hydraulic control system and control method for the chassis of an all-in-one cleaning and screening machine, which can realize effective control of the all-in-one cleaning and screening machine in different walking modes. Summary of the invention

[0007] The purpose of the present invention is to provide a hydraulic control system and control method for the chassis of an integrated cleaning and screening machine, aiming to solve the technical problem that the traditional chassis hydraulic control system cannot effectively control different walking modes of the chassis.

[0008] To achieve the above-mentioned purpose, in a first aspect, the present invention provides a hydraulic control system for a chassis of a cleaning and screening machine, comprising a crawler hydraulic control unit for controlling crawler travel, a rail wheel hydraulic control unit for controlling rail wheel travel, and a rail wheel lifting cylinder for performing rail wheel lifting, as well as a rail wheel floating hydraulic control valve, a rail wheel floating pilot valve, a rail wheel travel switching valve, a rail wheel unlocking valve, a cylinder control valve, and a shuttle valve;

[0009] The rail wheel hydraulic control unit comprises a hydraulic motor, a hydraulic motor control valve connected to two working oil ports of the hydraulic motor, and a wheel-rail brake for braking the hydraulic motor;

[0010] The rail wheel travel switching valve and the oil port of the oil cylinder control valve are connected in series, and are used to switch the oil supply of the central rotary joint to the rail wheel hydraulic control unit or the crawler track hydraulic control unit;

[0011] The working oil port of the rail wheel floating pilot valve is connected to the third oil port of the shuttle valve, and is also connected to the pilot oil port of the rail wheel floating hydraulic control valve;

[0012] The working oil port of the rail wheel unlocking valve is connected to the second oil port of the shuttle valve, and the first oil port of the shuttle valve is connected to the wheel-rail brake;

[0013] When the rail wheel floating pilot valve is energized, the wheel-rail brake releases the brake on the hydraulic motor, the rail wheel floating hydraulic control valve is in the second working position, and the two oil ports of the hydraulic motor are connected through the rail wheel floating hydraulic control valve, so that the rail wheel drive device is in a floating state;

[0014] The rail wheel unlocking valve is used to control the braking / contact braking of the hydraulic motor by the wheel-rail brake when the rail wheel is traveling.

[0015] As a further improvement of the above scheme, the rail wheel floating hydraulic control valve is a two-position six-way hydraulic control valve, whose first oil port is connected to the A oil port of the left hydraulic motor, its second oil port is connected to the A oil port of the right hydraulic motor, its fifth oil port is connected to the B oil port of the left hydraulic motor, and its sixth oil port is connected to the B oil port of the right hydraulic motor;

[0016] When the rail wheel floating hydraulic control valve is in the first working position, its first oil port is connected to its third oil port, its second oil port is connected to its fourth oil port, and its fifth oil port, its sixth oil port and the remaining oil ports are not connected to each other;

[0017] When the rail wheel floating hydraulic control valve is in the second working position, its first oil port is connected to its fifth oil port, its second oil port is connected to its sixth oil port, and its third oil port and its fourth oil port are not connected to the remaining oil ports.

[0018] As a further improvement of the above scheme, the rail wheel travel switching valve and the cylinder control valve are both two-position six-way solenoid valves, the first oil port and the second oil port of the rail wheel travel switching valve are respectively connected to the corresponding oil supply ports of the central rotary joint, the third oil port is connected to the first oil port of the cylinder control valve, the fourth oil port is connected to the second oil port of the cylinder control valve, the fifth oil port is connected to the first oil port of the rail wheel hydraulic control unit, and the sixth oil port is connected to the second oil port of the rail wheel hydraulic control unit;

[0019] The third oil port of the cylinder control valve is connected to the first oil port of the track hydraulic control unit, the fourth oil port is connected to the second oil port of the track hydraulic control unit, the fifth oil port is connected to the rod chamber of the rail wheel lifting cylinder, and the sixth oil port is connected to the rodless chamber of the rail wheel lifting cylinder.

[0020] As a further improvement of the above scheme, when the rail wheel travel switching valve and the cylinder control valve are both powered off, both valves are in the first working position, oil is supplied to the crawler hydraulic control unit through the central swivel joint, and the hydraulic oil in the rail wheel hydraulic control unit returns to the oil tank through the oil drain line;

[0021] When the rail wheel travel switching valve and the oil cylinder control valve are both energized, the two valves are in the second working position, and oil is supplied to the rail wheel hydraulic control unit through the central swivel joint, and the hydraulic oil in the crawler hydraulic control unit returns to the oil tank through the oil drain line;

[0022] The rail wheel travel switching valve is not energized and is in the first working position; at the same time, the cylinder control valve is energized and is in the second working position, and oil is supplied to the rail wheel lifting cylinder through the central swivel joint.

[0023] As a further improvement of the above scheme, when the rail wheel travel switching valve and the cylinder control valve are in the first working position, their first oil port is connected to their third oil port, their second oil port is connected to their fourth oil port; their fifth oil port and their sixth oil port are not connected to the other oil ports;

[0024] When the rail wheel travel switching valve and the cylinder control valve are in the second working position, their first oil port is connected to their fifth oil port, and their second oil port is connected to their sixth oil port; their third oil port and their fourth oil port are not connected to the other oil ports.

[0025] As a further improvement of the above solution, a two-position two-way solenoid valve is further provided between the first oil port of the shuttle valve and the wheel-rail brake.

[0026] As a further improvement of the above solution, the oil inlet of the rail wheel lifting cylinder is provided with a balancing valve which is pilot-controlled to each other.

[0027] In a second aspect, the present invention further provides a control method for a hydraulic control system of a chassis of a cleaning and screening machine as provided in the first aspect, the steps of which include:

[0028] S1. When crawler drive is running:

[0029] First, put the rail wheel drive device in the automatic floating state, and then cut off the power to the rail wheel travel switching valve and the oil cylinder control valve. Both valves are in the first working position, and the crawler hydraulic control unit is supplied with oil through the central swivel joint to make the crawler travel;

[0030] S2, when the rail wheel is driven:

[0031] S21, first release the floating state of the rail-wheel drive device, and brake the hydraulic motor with the wheel-rail brake; then control the rail-wheel lifting cylinder to move down the rail-wheel drive device, so that the rail-wheel drive device is in a parking brake state;

[0032] S22, when the control handle drives the rail wheel drive device to move, the pilot signal of the handle energizes the rail wheel unlocking valve, and the pilot control oil opens the corresponding wheel-rail brake through the shuttle valve to release the brake on the rail wheel drive device; the pilot signal of the handle controls the rail wheel travel switching valve to supply oil to the rail wheel hydraulic control unit to make the rail wheel drive device move;

[0033] S23. When parking is required, the control handle is completely closed, the pilot pressure returns to zero and then a preset time is delayed. After the hydraulic motor has initially braked, the rail wheel unlocking valve is controlled to lose power, the wheel-rail brake brakes the hydraulic motor, and the rail wheel drive device returns to the parking brake state.

[0034] As a further improvement of the above solution, in step S1, the method steps for making the rail wheel driving device in an automatic floating state are as follows:

[0035] The rail wheel floating pilot valve is energized, and the pilot control oil opens the corresponding wheel-rail brake through the shuttle valve. At the same time, the pilot control oil pushes the rail wheel floating hydraulic control valve to the second working position, and the two working oil ports of the hydraulic motors on the left and right sides for driving the rail wheels are in a connected state through the rail wheel floating hydraulic control valve, so that the rail wheel drive device is in an automatic floating state.

[0036] As a further improvement of the above solution, in step S21, the method steps for releasing the floating state of the rail wheel driving device are as follows:

[0037] First, the rail wheel floating pilot valve is controlled to lose power, the pilot control oil is cut off, the wheel-rail brake is in a locked state, the rail wheel floating switching valve is in the first working position, and the connection between the two working oil ports of the hydraulic motors on the left and right sides is cut off.

[0038] As a further improvement of the above scheme, in step S21, the method steps of controlling the rail wheel lifting cylinder to move the rail wheel driving device are as follows:

[0039] The control rail wheel travel switching valve loses power and is in the first working position. At the same time, the cylinder control valve is energized and is in the second working position. The high-pressure oil at the oil supply port of the central rotary interface is supplied to the rail wheel lifting cylinder through the rail wheel travel switching valve and the oil ports corresponding to the cylinder control valve to lower the rail wheel to the specified position.

[0040] As a further improvement of the above scheme, in step S22, the method steps of controlling the rail wheel travel switching valve to supply oil to the rail wheel hydraulic control unit are as follows:

[0041] When the rail wheel travel switching valve is energized, it is in the second working position, and the cylinder control valve is de-energized and in the first working position; the central swivel joint oil supply port supplies oil to the rail wheel hydraulic control unit, and the hydraulic oil in the crawler hydraulic control unit returns to the oil tank through the oil drain circuit.

[0042] Since the present invention adopts the above technical solution, the beneficial effects of this application are:

[0043] 1. A hydraulic control system for the chassis of a cleaning and screening machine provided by the present invention realizes oil circuit switching of the switching control of the track hydraulic control unit and the rail wheel hydraulic control unit by the rail wheel travel switching valve and the oil port of the cylinder control valve in series connection, thereby realizing switching of different walking modes of the chassis; in order to achieve better control, the present invention is also provided with a rail wheel floating pilot valve, a rail wheel floating hydraulic control valve and a shuttle valve, which are respectively connected to the corresponding oil ports of the rail wheel floating hydraulic control valve and the shuttle valve through the rail wheel floating pilot valve, and the pilot control oil opens the wheel-rail brake on the hydraulic motor of the rail wheel driving device through the shuttle valve, and the pilot control The oil is pressed to push the rail wheel floating hydraulic control valve to the corresponding working position, so that the two working oil ports of the hydraulic motor are in a connected state through the rail wheel floating hydraulic control valve, so that the rail wheel driving device can be in a free floating state; at the same time, an additional rail wheel unlocking valve is provided. The setting of the rail wheel unlocking valve can realize that when the rail wheel is driven to move, the opening of the wheel-rail brake is controlled by the rail wheel unlocking valve, so as to effectively brake the chassis or start walking. Specifically, when the chassis is stationary, the rail wheel unlocking valve controls the wheel-rail brake to be locked, so as to realize braking and parking when the rail wheel is stationary; when the rail wheel is moving, the wheel-rail brake is started and opened in time. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0045] Figure 1 It is a schematic diagram of a hydraulic control system of a chassis of a cleaning and screening machine disclosed in the present invention;

[0046] Figure 2 for Figure 1 A local enlarged schematic diagram of the I direction.

[0047] Reference numerals:

[0048] 1. Track hydraulic control unit; 2. Rail wheel hydraulic control unit; 21. Hydraulic motor; 22. Hydraulic motor control valve; 23. Wheel-rail brake; 3. Rail wheel lifting cylinder; 4. Rail wheel floating hydraulic control valve; 5. Rail wheel floating pilot valve; 6. Rail wheel travel switching valve; 7. Rail wheel unlocking valve; 8. Cylinder control valve; 9. Shuttle valve.

[0049] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with the implementation methods and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] It should be noted that all directional indications (such as up, down, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0052] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0053] Furthermore, the technical solutions between the various embodiments of the present invention may be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in the field. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0054] Example 1

[0055] See also Figure 1 and Figure 2 The present invention provides a hydraulic control system for the chassis of a cleaning and screening machine, including a crawler hydraulic control unit 1 for controlling crawler travel, a rail wheel hydraulic control unit 2 for controlling rail wheel travel, and a rail wheel lifting cylinder 3 for performing rail wheel lifting, as well as a rail wheel floating hydraulic control valve 4, a rail wheel floating pilot valve 5, a rail wheel travel switching valve 6, a rail wheel unlocking valve 7, a cylinder control valve 8 and a shuttle valve 9;

[0056] It should be noted that the chassis of the cleaning and screening machine includes a left walking track and a right walking track, and a rail wheel driving device is respectively provided at both ends of the walking track on each side, and is symmetrically arranged on the left and right. In order to clearly illustrate the inventive concept of the present invention, the hydraulic control system on either side is taken as an example for explanation;

[0057] The rail-wheel hydraulic control unit 2 comprises a hydraulic motor 21, a hydraulic motor control valve 22 connected to two working oil ports of the hydraulic motor 21, and a wheel-rail brake 23 for braking the hydraulic motor 21;

[0058] The oil ports of the rail wheel travel switching valve 6 and the cylinder control valve 8 are connected in series, and are used to switch the oil supply of the central rotary joint to the rail wheel hydraulic control unit 2 or the crawler track hydraulic control unit 1;

[0059] The working oil port of the rail wheel floating pilot valve 5 is connected to the third oil port of the shuttle valve 9, and is also connected to the pilot oil port of the rail wheel floating hydraulic control valve 4;

[0060] The working oil port of the rail wheel unlocking valve 7 is connected to the second oil port of the shuttle valve 9, and the first oil port of the shuttle valve 9 is connected to the wheel-rail brake 23;

[0061] When the rail wheel floating pilot valve 5 is energized, the wheel-rail brake 23 releases the brake on the hydraulic motor 21, the rail wheel floating hydraulic control valve 4 is in the second working position, and the two oil ports of the hydraulic motor 21 are connected through the rail wheel floating hydraulic control valve 4, so that the rail wheel drive device is in a floating state;

[0062] The rail wheel unlocking valve 7 is used to control the braking / contact braking of the hydraulic motor 21 by the wheel-rail brake 23 when the rail wheel is moving;

[0063] The present invention realizes the oil circuit switching of the track hydraulic control unit 1 and the rail wheel hydraulic control unit 2 by connecting the oil ports of the rail wheel travel switching valve 6 and the oil cylinder control valve 8 in series, thereby realizing the switching of different walking modes of the chassis; in order to achieve better control, the present invention is also provided with a rail wheel floating pilot valve 5, a rail wheel floating hydraulic control valve 4 and a shuttle valve 9, and the rail wheel floating pilot valve 5 is respectively connected to the corresponding oil ports of the rail wheel floating hydraulic control valve 4 and the shuttle valve 9, and the pilot control oil opens the wheel-rail brake 23 on the hydraulic motor 21 of the rail wheel driving device through the shuttle valve 9, and the pilot control oil pushes the rail wheel floating hydraulic control valve 4 and the shuttle valve 9 to open the hydraulic motor 21 of the rail wheel driving device. The control valve 4 moves to the corresponding working position, so that the two working oil ports of the hydraulic motor 21 are in a connected state through the rail wheel floating hydraulic control valve 4, so that the rail wheel driving device can be in a free floating state; at the same time, an additional rail wheel unlocking valve 7 is provided. The setting of the rail wheel unlocking valve 7 can realize that when the rail wheel is driven to move, the wheel-rail brake 23 is controlled by the rail wheel unlocking valve 7 to open, so as to effectively brake the chassis or start walking. Specifically, when the chassis is stationary, the rail wheel unlocking valve 7 controls the wheel-rail brake 23 to lock, so as to realize braking and parking when the rail wheel is stationary; when the rail wheel is moving, the wheel-rail brake 23 is started and opened in time.

[0064] As a preferred embodiment, the rail wheel floating hydraulic control valve 4 is a two-position six-way hydraulic control valve, whose first oil port is connected to the A oil port of the hydraulic motor 21 of the left rail wheel drive device, whose second oil port is connected to the A oil port of the hydraulic motor 21 of the right rail wheel drive device, whose fifth oil port is connected to the B oil port of the hydraulic motor 21 of the left rail wheel drive device, and whose sixth oil port is connected to the B oil port of the hydraulic motor 21 of the right rail wheel drive device;

[0065] When the rail wheel floating hydraulic control valve 4 is in the first working position, its first oil port is connected to its third oil port, its second oil port is connected to its fourth oil port, and its fifth oil port, its sixth oil port and the remaining oil ports are not connected to each other; the two working oil ports of the hydraulic motors 21 on both sides are in a cut-off state;

[0066] When the rail wheel floating hydraulic control valve 4 is in the second working position, its first oil port is connected to its fifth oil port, its second oil port is connected to its sixth oil port, and its third oil port and its fourth oil port are not connected to the remaining oil ports; that is, when the rail wheel floating hydraulic control valve 4 is in the second working position, the hydraulic motor 21 on the left side is connected to the fifth oil circuit through the first oil port of the rail wheel floating hydraulic control valve 4, so that the left rail wheel drive device is in a free floating state; the hydraulic motor 21 on the right side is connected to the second oil port and the sixth oil port of the rail wheel floating hydraulic control valve 4, so that the right rail wheel drive device is in a free floating state;

[0067] In the present invention, by reasonably connecting the rail wheel floating pilot valve 5 with the shuttle valve 9 and the pilot oil port of the rail wheel floating hydraulic control valve 4, while releasing the braking of the hydraulic motor 21 by the wheel-rail brake 23, the pilot control oil provided by the rail wheel floating pilot valve 5 pushes the movement of the valve core of the rail wheel floating hydraulic control valve 4, so that the two working oil ports of the hydraulic motor 21 are connected through the rail wheel floating hydraulic control valve 4, so that the rail wheel drive device is in a free floating state.

[0068] As a preferred embodiment, the rail wheel travel switching valve 6 and the cylinder control valve 8 are both two-position six-way solenoid valves, the first oil port and the second oil port of the rail wheel travel switching valve 6 are respectively connected to the corresponding oil supply port of the central rotary joint, the third oil port is connected to the first oil port of the cylinder control valve 8, the fourth oil port is connected to the second oil port of the cylinder control valve 8, the fifth oil port is connected to the first oil port of the rail wheel hydraulic control unit 2, and the sixth oil port is connected to the second oil port of the rail wheel hydraulic control unit 2;

[0069] The third oil port of the oil cylinder control valve 8 is connected to the first oil port of the track hydraulic control unit 1, the fourth oil port is connected to the second oil port of the track hydraulic control unit 1, the fifth oil port is connected to the rod chamber of the rail wheel lifting oil cylinder 3, and the sixth oil port is connected to the rodless chamber of the rail wheel lifting oil cylinder 3;

[0070] When the rail wheel travel switching valve 6 and the oil cylinder control valve 8 are in the first working position, the first oil port is connected to the third oil port, the second oil port is connected to the fourth oil port; the fifth oil port and the sixth oil port are not connected to the other oil ports;

[0071] When the rail wheel travel switching valve 6 and the oil cylinder control valve 8 are in the second working position, the first oil port is connected to the fifth oil port, the second oil port is connected to the sixth oil port; the third oil port and the fourth oil port are not connected to the other oil ports;

[0072] When the rail wheel travel switching valve 6 and the cylinder control valve 8 are both powered off, the two valves are in the first working position, and oil is supplied to the track hydraulic control unit 1 through the central rotary joint, and the hydraulic oil in the rail wheel hydraulic control unit 2 returns to the oil tank through the oil drain circuit; specifically, the pressure oil enters the first oil port of the rail wheel travel switching valve 6 through the first oil supply port of the central rotary joint, and then flows out through its third oil port and then enters the first oil port of the cylinder control valve 8, and then enters the first oil port of the track hydraulic control unit 1 through the third oil port of the cylinder control valve 8 to provide pressure oil to the track hydraulic control unit 1, and at the same time, the low-pressure oil flows out through the second oil port of the track hydraulic control unit 1, first enters the fourth oil port of the cylinder control valve 8, and then flows out through its second oil port, and then enters the fourth oil port of the rail wheel travel switching valve 6 and then flows out through its second oil port and enters the second oil port of the central rotary joint to return to the oil tank;

[0073] When the rail wheel travel switching valve 6 and the cylinder control valve 8 are both energized, the two valves are in the second working position, and oil is supplied to the rail wheel hydraulic control unit 2 through the central rotary joint, and the hydraulic oil in the track hydraulic control unit 1 returns to the oil tank through the oil drain circuit; specifically, the pressure oil enters the first oil port of the rail wheel travel switching valve 6 through the first oil supply port of the central rotary joint, and then flows out through its fifth oil port and enters the first oil port of the rail wheel hydraulic control unit 2 to provide pressure oil to the rail wheel hydraulic control unit 2, while the low-pressure oil flows out through the second oil port of the rail wheel hydraulic control unit 2 and first enters the sixth oil port of the rail wheel travel switching valve 6 and then flows out through its second oil port, enters the second oil port of the central rotary joint and returns to the oil tank; the hydraulic oil in the track hydraulic control unit 1 is respectively drained to the oil tank through the fifth oil port and the sixth oil port of the cylinder control valve 8;

[0074] The rail-wheel travel switching valve 6 is not energized and is in the first working position; at the same time, the cylinder control valve 8 is energized and in the second working position, and oil is supplied to the rail-wheel lifting cylinder 3 through the central rotary joint; specifically, the pressure oil enters the first oil port of the rail-wheel travel switching valve 6 through the first oil supply port of the central rotary joint, and then flows out through its third oil port and then enters the first oil port of the cylinder control valve 8, and then enters the rod chamber of the wheel-rail lifting cylinder through the fifth oil port of the cylinder control valve 8; similarly, the pressure oil enters the second oil port of the rail-wheel travel switching valve 6 through the second oil supply port of the central rotary joint, and then flows out through its fourth oil port and then enters the second oil port of the cylinder control valve 8, and then enters the rodless chamber of the wheel-rail lifting cylinder through the sixth oil port of the cylinder control valve 8.

[0075] As a preferred embodiment, a two-position two-way solenoid valve is further provided between the first oil port of the shuttle valve 9 and the wheel-rail brake 23. By de-energizing the two-position two-way solenoid valve and combining with the movement of the shuttle valve 9, the wheel-rail brake 23 is actuated.

[0076] As a preferred embodiment, the oil inlet of the rail wheel lifting cylinder 3 is provided with a balancing valve which is pilot-controlled to each other.

[0077] Example 2

[0078] The present invention also provides a control method for a hydraulic control system of a chassis of a cleaning and screening machine as provided in Example 1, the steps of which include:

[0079] S1. When crawler drive is running:

[0080] First, the rail wheel drive device is in the automatic floating state, and then the rail wheel travel switching valve 6 and the cylinder control valve 8 are both powered off, and both valves are in the first working position, and the crawler hydraulic control unit 1 is supplied with oil through the central swivel joint to make the crawler travel;

[0081] The method steps for making the rail wheel drive device in an automatic floating state are as follows:

[0082] The rail wheel floating pilot valve 5 is energized, and the pilot control oil opens the corresponding wheel-rail brake 23 through the shuttle valve 9. At the same time, the pilot control oil pushes the rail wheel floating hydraulic control valve 4 to the second working position, and the two working oil ports of the hydraulic motor 21 on the left and right sides for driving the rail wheel are in a connected state through the rail wheel floating hydraulic control valve 4, so that the rail wheel drive device is in an automatic floating state;

[0083] S2, when the rail wheel is driven:

[0084] S21, first release the floating state of the rail-wheel drive device, and the wheel-rail brake 23 brakes the hydraulic motor 21; then control the rail-wheel lifting cylinder 3 to move down the rail-wheel drive device, so that the rail-wheel drive device is in a parking brake state;

[0085] The method steps for releasing the floating state of the rail wheel drive device are as follows:

[0086] First, the rail wheel floating pilot valve 5 is controlled to lose power, the pilot control oil is cut off, the wheel-rail brake 23 is in a locked state, the rail wheel floating switching valve is in the first working position, and the connection state of the two working oil ports of the left and right hydraulic motors 21 is cut off;

[0087] The method and steps for controlling the rail wheel lifting cylinder 3 to move and lower the rail wheel driving device are as follows:

[0088] The rail wheel travel switching valve 6 is controlled to lose power and is in the first working position. At the same time, the oil cylinder control valve 8 is powered and is in the second working position. The high-pressure oil at the oil supply port of the central rotary interface is supplied to the rail wheel lifting cylinder 3 through the oil ports corresponding to the rail wheel travel switching valve 6 and the oil cylinder control valve 8 to lower the rail wheel to the specified position.

[0089] S22, when the control handle drives the rail wheel drive device to move, the pilot signal of the handle energizes the rail wheel unlocking valve 7, and the pilot control oil opens the corresponding wheel-rail brake 23 through the shuttle valve 9 to release the brake on the rail wheel drive device; the handle pilot signal controls the rail wheel travel switching valve 6 to supply oil to the rail wheel hydraulic control unit 2 to make the rail wheel drive device move;

[0090] The method and steps for controlling the rail wheel travel switching valve 6 to supply oil to the rail wheel hydraulic control unit 2 are as follows:

[0091] When the rail wheel travel switching valve 6 is powered on, it is in the second working position, and the oil cylinder control valve 8 is powered off and in the first working position; the central rotary joint oil supply port supplies oil to the rail wheel hydraulic control unit 2, and the hydraulic oil in the crawler hydraulic control unit 1 returns to the oil tank through the oil drain line;

[0092] S23, when parking is required, the control handle is completely closed, the pilot pressure returns to zero and then a preset time is delayed, after the hydraulic motor 21 is initially braked, the rail wheel unlocking valve 7 is controlled to lose power, the wheel-rail brake 23 brakes the hydraulic motor 21, and the rail wheel drive device returns to the parking brake state;

[0093] The control method provided by the present invention can realize the smooth switching between the crawler-driven walking and the rail-wheel-driven walking of the chassis of the cleaning and screening machine, and can make the rail-wheel driving device in a floating state during the crawler-driven walking;

[0094] It is also possible to brake and park the rail wheel through the wheel-rail brake 23 when the rail wheel is driven and stationary; the wheel-rail brake 23 can be started and opened in time when the rail wheel is moving, and the brake is closed with a momentary delay when the rail wheel stops, so that the hydraulic motor 21 is first used for buffer braking and then the wheel-rail brake 23 is started for parking.

[0095] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A hydraulic control system for the chassis of a cleaning and screening machine, characterized in that: It includes a crawler hydraulic control unit for controlling crawler travel, a rail wheel hydraulic control unit for controlling rail wheel travel, and a rail wheel lifting cylinder for performing rail wheel lifting, as well as a rail wheel floating hydraulic control valve, a rail wheel floating pilot valve, a rail wheel travel switching valve, a rail wheel unlocking valve, a cylinder control valve and a shuttle valve; The rail wheel hydraulic control unit comprises a hydraulic motor, a hydraulic motor control valve connected to two working oil ports of the hydraulic motor, and a wheel-rail brake for braking the hydraulic motor; The rail wheel travel switching valve and the oil port of the oil cylinder control valve are connected in series, and are used to switch the oil supply of the central rotary joint to the rail wheel hydraulic control unit or the crawler track hydraulic control unit; The working oil port of the rail wheel floating pilot valve is connected to the third oil port of the shuttle valve, and is also connected to the pilot oil port of the rail wheel floating hydraulic control valve; The working oil port of the rail wheel unlocking valve is connected to the second oil port of the shuttle valve, and the first oil port of the shuttle valve is connected to the wheel-rail brake; When the rail wheel floating pilot valve is energized, the wheel-rail brake releases the brake on the hydraulic motor, the rail wheel floating hydraulic control valve is in the second working position, and the two oil ports of the hydraulic motor are connected through the rail wheel floating hydraulic control valve, so that the rail wheel drive device is in a floating state; The rail wheel unlocking valve is used to control the braking / contact braking of the hydraulic motor by the wheel-rail brake when the rail wheel is traveling.

2. The hydraulic control system of the chassis of the integrated cleaning and screening machine according to claim 1, characterized in that: The rail wheel floating hydraulic control valve is a two-position six-way hydraulic control valve, whose first oil port is connected to the A oil port of the left hydraulic motor, its second oil port is connected to the A oil port of the right hydraulic motor, its fifth oil port is connected to the B oil port of the left hydraulic motor, and its sixth oil port is connected to the B oil port of the right hydraulic motor; When the rail wheel floating hydraulic control valve is in the first working position, its first oil port is connected to its third oil port, its second oil port is connected to its fourth oil port, and its fifth oil port, its sixth oil port and the remaining oil ports are not connected to each other; When the rail wheel floating hydraulic control valve is in the second working position, its first oil port is connected to its fifth oil port, its second oil port is connected to its sixth oil port, and its third oil port and its fourth oil port are not connected to the remaining oil ports.

3. A hydraulic control system for a chassis of a cleaning and screening machine according to claim 1 or 2, characterized in that: The rail wheel travel switching valve and the cylinder control valve are both two-position six-way solenoid valves, the first oil port and the second oil port of the rail wheel travel switching valve are respectively connected to the corresponding oil supply port of the central rotary joint, the third oil port is connected to the first oil port of the cylinder control valve, the fourth oil port is connected to the second oil port of the cylinder control valve, the fifth oil port is connected to the first oil port of the rail wheel hydraulic control unit, and the sixth oil port is connected to the second oil port of the rail wheel hydraulic control unit; The third oil port of the cylinder control valve is connected to the first oil port of the track hydraulic control unit, the fourth oil port is connected to the second oil port of the track hydraulic control unit, the fifth oil port is connected to the rod chamber of the rail wheel lifting cylinder, and the sixth oil port is connected to the rodless chamber of the rail wheel lifting cylinder.

4. A hydraulic control system for a chassis of a cleaning and screening machine according to claim 1 or 2, characterized in that: When the rail wheel travel switching valve and the oil cylinder control valve are both powered off, both valves are in the first working position, oil is supplied to the crawler hydraulic control unit through the central swivel joint, and the hydraulic oil in the rail wheel hydraulic control unit returns to the oil tank through the oil drain line; When the rail wheel travel switching valve and the oil cylinder control valve are both energized, the two valves are in the second working position, and oil is supplied to the rail wheel hydraulic control unit through the central swivel joint, and the hydraulic oil in the crawler hydraulic control unit returns to the oil tank through the oil drain line; The rail wheel travel switching valve is not energized and is in the first working position; at the same time, the cylinder control valve is energized and is in the second working position, and oil is supplied to the rail wheel lifting cylinder through the central swivel joint.

5. The hydraulic control system for the chassis of the integrated cleaning and screening machine according to claim 4, characterized in that: When the rail wheel travel switching valve and the oil cylinder control valve are in the first working position, the first oil port and the third oil port are connected, the second oil port and the fourth oil port are connected; the fifth oil port and the sixth oil port are not connected with the other oil ports; When the rail wheel travel switching valve and the cylinder control valve are in the second working position, their first oil port is connected to their fifth oil port, and their second oil port is connected to their sixth oil port; their third oil port and their fourth oil port are not connected to the other oil ports.

6. A control method for a hydraulic control system of a cleaning and screening machine chassis according to any one of claims 1 to 5, characterized in that: The steps include: S1. When crawler drive is running: First, put the rail wheel drive device in the automatic floating state, and then cut off the power to the rail wheel travel switching valve and the oil cylinder control valve. Both valves are in the first working position, and the crawler hydraulic control unit is supplied with oil through the central swivel joint to make the crawler travel; S2, when the rail wheel is driven: S21, first release the floating state of the rail-wheel drive device, and brake the hydraulic motor with the wheel-rail brake; then control the rail-wheel lifting cylinder to move down the rail-wheel drive device, so that the rail-wheel drive device is in a parking brake state; S22, when the control handle drives the rail wheel drive device to move, the pilot signal of the handle energizes the rail wheel unlocking valve, and the pilot control oil opens the corresponding wheel-rail brake through the shuttle valve to release the brake on the rail wheel drive device; the pilot signal of the handle controls the rail wheel travel switching valve to supply oil to the rail wheel hydraulic control unit to make the rail wheel drive device move; S23. When parking is required, the control handle is completely closed, the pilot pressure returns to zero and then a preset time is delayed. After the hydraulic motor has initially braked, the rail wheel unlocking valve is controlled to lose power, the wheel-rail brake brakes the hydraulic motor, and the rail wheel drive device returns to the parking brake state.

7. The control method according to claim 6, characterized in that: In step S1, the method steps for making the rail wheel drive device in an automatic floating state are as follows: The rail wheel floating pilot valve is energized, and the pilot control oil opens the corresponding wheel-rail brake through the shuttle valve. At the same time, the pilot control oil pushes the rail wheel floating hydraulic control valve to the second working position, and the two working oil ports of the hydraulic motors on the left and right sides for driving the rail wheels are in a connected state through the rail wheel floating hydraulic control valve, so that the rail wheel drive device is in an automatic floating state.

8. The control method according to claim 6 or 7, characterized in that: In step S21, the method steps for releasing the floating state of the rail wheel drive device are as follows: First, the rail wheel floating pilot valve is controlled to lose power, the pilot control oil is cut off, the wheel-rail brake is in a locked state, the rail wheel floating switching valve is in the first working position, and the connection between the two working oil ports of the hydraulic motors on the left and right sides is cut off.

9. The control method according to claim 6 or 7, characterized in that: In step S21, the method steps of controlling the rail wheel lifting cylinder to move the rail wheel driving device are as follows: The control rail wheel travel switching valve loses power and is in the first working position. At the same time, the cylinder control valve is energized and is in the second working position. The high-pressure oil at the oil supply port of the central rotary interface is supplied to the rail wheel lifting cylinder through the rail wheel travel switching valve and the oil ports corresponding to the cylinder control valve to lower the rail wheel to the specified position.

10. The control method according to claim 6 or 7, characterized in that: In step S22, the method steps of controlling the rail wheel travel switching valve to supply oil to the rail wheel hydraulic control unit are as follows: When the rail wheel travel switching valve is energized, it is in the second working position, and the cylinder control valve is de-energized and in the first working position; the central swivel joint oil supply port supplies oil to the rail wheel hydraulic control unit, and the hydraulic oil in the crawler hydraulic control unit returns to the oil tank through the oil drain circuit.

Images