An integrated pilot valve group for hydraulic travel control

Abstract

The present invention discloses an integrated pilot valve group for hydraulic travel control, including a parking solenoid valve, an electric-controlled proportional pressure reducing valve and a three-position four-way solenoid reversing valve connected in sequence between an oil source valve and a travel main valve, the electromagnet of the parking solenoid valve is connected to a power supply through a parking button switch, the electric-controlled proportional pressure reducing valve and an angle sensor on an electronic accelerator pedal are connected to a controller, and the controller controls the oil pressure at the output end of the electric-controlled proportional pressure reducing valve through the angle of the electronic accelerator pedal. When the parking solenoid valve of the present invention is energized, the parking brake is opened, and a pilot oil source for the travel main valve is provided at the same time, the three-position four-way solenoid valve is energized to realize gear control, and the controller adjusts the output pressure of the electric-controlled proportional pressure reducing valve according to the pedaling angle of the electronic accelerator pedal, thereby realizing the flow control of the travel main valve. The present invention has parking control, direction control and pressure control of the control end of the travel main valve, and realizes the parking and travel interlocking control functions at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulic travel control, in particular to an integrated pilot valve group for hydraulic travel control. Background Art

[0002] The hydraulic drive system is generally divided into an open system and a closed system. The open hydraulic travel system consists of an oil pump, a travel main valve and a travel motor, and the travel speed is controlled by the travel main valve. The closed system consists of an oil pump and a travel motor, and the travel speed is achieved by the variables of the oil pump and the travel motor.

[0003] Due to the large flow rate of the open hydraulic travel system, the travel main valve in the system generally adopts pilot control. One is direct control by the pedal valve. The flow rate of the main valve is linearly proportional to the amplitude of the pedal valve. The larger the pedal amplitude, the greater the flow rate provided by the main valve. The pedal valve can also achieve forward and backward control. This system is simple, but there are many pipelines and it cannot realize the electronic control function. The other is that two electronically controlled proportional pressure reducing valves control the two control ends of the travel main valve respectively. This system can realize remote control of the travel main valve, but this system requires the controller to control the two electronically controlled proportional pressure reducing valves respectively, and the control is more complicated. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an integrated pilot valve group for hydraulic travel control, which has the functions of parking control, direction control and travel main valve pressure control, and simultaneously realizes the parking and travel interlocking control function, and is particularly suitable for engineering vehicles with hydraulic travel control systems.

[0005] The technical solution of the present invention is:

[0006] An integrated pilot valve group for hydraulic travel control includes a parking solenoid valve, an electric proportional pressure reducing valve and a three-position four-way solenoid reversing valve which are sequentially connected between an oil source valve and a travel main valve. The parking solenoid valve, the electric proportional pressure reducing valve and the three-position four-way solenoid reversing valve are all installed on a valve block, that is, the oil outlet of the oil source valve is connected to the oil inlet of the parking solenoid valve, the oil outlet of the parking solenoid valve is respectively connected to the oil inlet of the parking brake of the valve block and the oil inlet of the electric proportional pressure reducing valve, and the oil outlet of the electric proportional pressure reducing valve is connected to the oil inlet of the three-position four-way solenoid reversing valve. The two working oil ports of the three-position four-way solenoid reversing valve are connected to the a port and the b port of the valve block respectively in a one-to-one correspondence, the a port and the b port of the valve block are connected to the two control oil ports of the travel main valve respectively in a one-to-one correspondence, the two working oil ports of the travel main valve are connected to the driving motor of the crane, the electromagnet of the parking solenoid valve is connected to the power supply through the parking button switch, the angle sensor on the proportional pressure reducing valve and the electronic accelerator pedal are connected to the controller, and the controller controls the oil pressure at the output end of the proportional pressure reducing valve through the angle of the electronic accelerator pedal.

[0007] The electromagnets on both sides of the three-position four-way electromagnetic reversing valve are correspondingly connected to the driving direction switch.

[0008] The oil inlet of the traveling main valve and the oil inlet of the oil source valve are both connected to an oil pump, and the oil pump delivers the hydraulic oil in the hydraulic oil tank to the traveling main valve and the oil source valve.

[0009] The oil return port of the parking solenoid valve, the oil return port of the three-position four-way solenoid reversing valve and the oil return port of the electronically controlled proportional pressure reducing valve are connected together through a valve block and then connected to the hydraulic oil tank.

[0010] The traveling driving motor includes driving motor A1, driving motor A2, driving motor B1 and driving motor B2. The working oil port of the traveling main valve is connected to the oil inlet of driving motor A1 and the oil inlet of driving motor A2 respectively. The working oil port of the traveling main valve is connected to the oil inlet of driving motor B1 and the oil inlet of driving motor B2 respectively.

[0011] Advantages of the present invention:

[0012] The present invention is composed of a parking solenoid valve, an electrically controlled proportional pressure reducing valve, a three-position four-way solenoid reversing valve and a valve block. When the parking solenoid valve is energized, the parking brake is opened and a pilot oil source for a traveling main valve is provided at the same time. The three-position four-way solenoid valve is energized to realize forward or backward control. A controller controls the electrically controlled proportional pressure reducing valve. The controller adjusts the output pressure of the electrically controlled proportional pressure reducing valve according to the pedaling angle of the electronic accelerator pedal, thereby realizing flow control of the traveling main valve, that is, the controller only controls the output pressure of the proportional pressure reducing valve, and the directional control valve and the parking valve are controlled separately. The valve group has parking control, directional control and pressure control of the traveling main valve control end, and realizes the parking and traveling interlocking control functions at the same time, so that the pilot pressure is zero and the vehicle cannot travel, which can effectively avoid damage to the brake in the reducer caused by the vehicle traveling when parking. The present invention is composed of a parking solenoid valve, an electrically controlled proportional pressure reducing valve, an electrically controlled proportional pressure reducing valve, a three-position four-way solenoid reversing valve and a valve block. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the present invention.

[0014] Figure 2 The present invention is applied to the principle diagram of the open hydraulic travel system. DETAILED DESCRIPTION

[0015] 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.

[0016] See Figure 1 and Figure 2 , an integrated pilot valve group for hydraulic travel control, including a parking solenoid valve 3, an electric-controlled proportional pressure reducing valve 4 and a three-position four-way solenoid reversing valve 5 which are sequentially connected between an oil source valve 1 and a travel main valve 2, the parking solenoid valve 3, the electric-controlled proportional pressure reducing valve 4 and the three-position four-way solenoid reversing valve 5 are all installed on a valve block 6, that is, the oil outlet of the oil source valve 1 is connected to the oil inlet (P port) of the parking solenoid valve 2, the oil outlet (A port) of the parking solenoid valve 2 is respectively connected to the parking brake oil inlet (Z1 port and Z2 port) of the valve block 6 and the oil inlet (P port) of the electric-controlled proportional pressure reducing valve 4, the oil outlet (A port) of the electric-controlled proportional pressure reducing valve 4 is connected to the oil inlet (P port) of the three-position four-way solenoid reversing valve 5, the two working oil ports (A port and B port) of the three-position four-way solenoid reversing valve 5 are respectively connected to the a port and the b port of the valve block 6 in a one-to-one correspondence, and the a port and the b port of the valve block 6 are respectively connected. The b ports are connected to the two control oil ports (a1 ports and b1 ports) of the travel main valve 2 in one-to-one correspondence. The travel drive motors include drive motors A1, A2, B1 and B2. The working oil port (A port) of the travel main valve 2 is connected to the oil inlet of the drive motor A1 and the oil inlet of the drive motor A2 respectively. The working oil port (B port) of the travel main valve 2 is connected to the oil inlet of the drive motor B1 and the oil inlet of the drive motor B2 respectively. The electromagnet of the parking solenoid valve 3 is connected to the power supply through the parking button switch. The angle sensor on the electronic proportional pressure reducing valve 4 and the electronic accelerator pedal are connected to the controller. The controller controls the oil pressure at the output end of the electronic proportional pressure reducing valve 4 through the angle of the electronic accelerator pedal. The electromagnets on both sides (Y3 and Y4) of the three-position four-way electromagnetic reversing valve 5 are connected to the travel direction switch in correspondence.

[0017] The oil inlet (P port) of the travel main valve 2 and the oil inlet (P port) of the oil source valve 1 are both connected to the oil pump 7. The oil pump 7 transports the hydraulic oil in the hydraulic oil tank 8 to the travel main valve 2 and the oil source valve 1; the oil return port (T port) of the parking solenoid valve, the oil return port (T port) of the electronically controlled proportional pressure reducing valve and the oil return port (T port) of the three-position four-way solenoid reversing valve are connected together through the valve block 6 and then connected to the hydraulic oil tank 8.

[0018] Working principle of the present invention:

[0019] When the vehicle starts, the forward gear of the driving direction switch is engaged, and the electromagnet Y4 of the three-position four-way solenoid reversing valve 5 is energized; the parking button is pressed, and the electromagnet Y1 of the parking solenoid valve is energized, and the control oil from the oil source valve 1 passes through the parking solenoid valve 3 from the P port to its A port, and is divided at the A port of the parking solenoid valve to the P port of the electronically controlled proportional pressure reducing valve 4 and the Z1 port and Z2 port of the valve block 6 (the parking brake oil inlet port), at which time the parking brake is opened; the electronic accelerator pedal is stepped on, and the controller collects the stepped angle according to the angle sensor on the electronic accelerator pedal. The oil pressure output from the A port of the electronically controlled proportional pressure reducing valve 4 increases with the increase of the stepped angle of the electronic accelerator pedal, and the control oil adjusted by the electronically controlled proportional pressure reducing valve 4 reaches the a port of the valve block 6 through the A port of the three-position four-way solenoid reversing valve 5, and the a port of the valve block 6 is connected to the control oil port -a1 port of the travel main valve 2, and the valve core of the travel main valve 2 moves to the right, and the travel main valve 2 The openings of ports A and B are linearly proportional to the input oil pressure of port a1 of the travel main valve 2. The flow of hydraulic oil through the travel main valve 2 changes proportionally from 0 to the maximum. The greater the flow, the higher the speed of the drive motor, thereby achieving vehicle starting and speed control. When the reverse gear of the driving direction switch is engaged, the electromagnet Y3 of the three-position four-way electromagnetic reversing valve 5 is energized, the pilot pressure is reversed, the valve core of the travel main valve 2 moves to the left, the oil inlet (P port) and the oil return port (T port) of the travel main valve 2 are reversed to the two working oil ports (ports A and B), and the vehicle moves backward.

[0020] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An integrated pilot valve group for hydraulic travel control, characterized in that: It includes a parking solenoid valve, an electric-controlled proportional pressure reducing valve and a three-position four-way solenoid reversing valve which are sequentially connected between the oil source valve and the travel main valve. The parking solenoid valve, the electric-controlled proportional pressure reducing valve and the three-position four-way solenoid reversing valve are all installed on the valve block, that is, the oil outlet of the oil source valve is connected to the oil inlet of the parking solenoid valve, the oil outlet of the parking solenoid valve is respectively connected to the parking brake oil inlet of the valve block and the oil inlet of the electric-controlled proportional pressure reducing valve, the oil outlet of the electric-controlled proportional pressure reducing valve is connected to the oil inlet of the three-position four-way solenoid reversing valve, the two working oil ports of the three-position four-way solenoid reversing valve are respectively connected to the a port and the b port of the valve block in a one-to-one correspondence, and the a port and the b port of the valve block are respectively The two control oil ports of the travel main valve are connected one by one, and the two working oil ports of the travel main valve are connected to the driving motor. The electromagnet of the parking solenoid valve is connected to the power supply through the parking button switch. The angle sensor on the proportional pressure reducing valve and the electronic accelerator pedal are connected to the controller. The controller controls the oil pressure at the output end of the proportional pressure reducing valve through the angle of the electronic accelerator pedal. The electromagnets on both sides of the three-position four-way solenoid reversing valve are connected to the driving direction switch. The oil inlet of the travel main valve and the oil inlet of the oil source valve are connected to the oil pump, and the oil pump transports the hydraulic oil in the hydraulic oil tank to the travel main valve and the oil source valve. When the vehicle starts, the driving direction switch is engaged in the forward gear, and the electromagnet Y4 of the three-position four-way solenoid reversing valve is energized; the parking button is pressed, and the electromagnet Y1 of the parking solenoid valve is energized, and the control oil from the oil source valve 1 passes through the parking solenoid valve from the P port to its A port, and is divided at the A port of the parking solenoid valve to the P port of the electronically controlled proportional pressure reducing valve and the Z1 port and Z2 port of the valve block. At this time, the parking brake is opened; the electronic accelerator pedal is stepped on, and the controller collects the stepped angle according to the angle sensor on the electronic accelerator pedal. The oil pressure output from the A port of the electronically controlled proportional pressure reducing valve increases with the increase of the stepped angle of the electronic accelerator pedal, and the control oil adjusted by the electronically controlled proportional pressure reducing valve is adjusted by the three-position four-way solenoid reversing valve. The A port of the three-position four-way solenoid reversing valve reaches the a port of the valve block, and the a port of the valve block is connected to the control oil port - a1 port of the travel main valve. The valve core of the travel main valve moves to the right, and the openings of the A port and B port of the travel main valve are linearly proportional to the input oil pressure of the a1 port of the travel main valve. The flow of the hydraulic oil through the travel main valve changes proportionally from 0 to the maximum. The larger the flow, the higher the speed of the drive motor, thereby realizing the starting and speed control of the vehicle; when the reverse gear of the driving direction switch is engaged, the electromagnet Y3 of the three-position four-way solenoid reversing valve is energized, the pilot pressure is reversed, the valve core of the travel main valve moves to the left, the oil inlet and return port of the travel main valve are reversed to the two working oil ports, and the vehicle moves backward.

2. The integrated pilot valve group for hydraulic travel control according to claim 1 is characterized in that: The oil return port of the parking solenoid valve, the oil return port of the electronically controlled proportional pressure reducing valve and the oil return port of the three-position four-way solenoid reversing valve are connected together through a valve block and then connected to the hydraulic oil tank.

3. The integrated pilot valve group for hydraulic travel control according to claim 1 is characterized in that: The traveling driving motor includes driving motor A1, driving motor A2, driving motor B1 and driving motor B2. The working oil port of the traveling main valve is connected to the oil inlet of driving motor A1 and the oil inlet of driving motor A2 respectively. The working oil port of the traveling main valve is connected to the oil inlet of driving motor B1 and the oil inlet of driving motor B2 respectively.

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