A multi-mode digital valve group hydraulic control system

Abstract

The present invention discloses a multi-mode digital valve group hydraulic control system, which mainly includes a pump source, an overflow digital valve group, a pressure compensation digital valve group, a forward speed regulation digital valve group, a reverse speed regulation digital valve group, a forward pressure regulation digital valve group, a reverse pressure regulation digital valve group, a multi-mode controller, and a pressure sensor. The digital valve group is composed of multiple digital valves with output flows arranged according to a certain rule in parallel, and has high redundancy and fault tolerance. This system only uses the digital valve group as the control element, overcomes the design concept of functional elementization in traditional hydraulic systems, transfers the functions from the hardware level to the software level, and can realize functions such as stable pressure overflow, multi-functional commutation, pressure compensation, speed and force compound control, etc. by means of software programming, and has the advantages of high intelligence, high reliability, and low cost.

Description

Technical Field

[0001] The present invention relates to the field of hydraulic technology, and particularly to a multi-mode digital valve group hydraulic control system. Background Art

[0002] Traditional hydraulic control systems generally consist of components such as hydraulic pumps, overflow valves, reversing valves, flow control valves, pressure control valves, hydraulic cylinders, and hydraulic motors. For the hydraulic control system of construction machinery, in a load-sensing multi-way valve system, there are dozens of different types of hydraulic components, which increases the complexity of the system.

[0003] The root cause of the above problems lies in the design concept of the existing hydraulic control system, which is based on component functionalization, that is, corresponding function control is achieved by designing or combining hydraulic valves with different functions. This causes the following problems: The system function completely depends on the types of hydraulic control valves, and the system output function can only be changed by adding or replacing hydraulic valves; The excessive types of hydraulic control valves will lead to an increase in system design, manufacturing, and maintenance costs; Existing flow and pressure control hydraulic valves are all based on the throttle port regulation principle, which is sensitive to oil contaminants and has low reliability; Each type of hydraulic valve is independent and does not have universality; Once a component fails, it may cause the system to stop running, and the system robustness is poor. Summary of the Invention

[0004] The present invention provides a multi-mode digital valve group hydraulic control system to solve the above problems existing in the prior art. It can not only achieve multi-functional control of the system, but also significantly improve the reliability and intelligence level of the system.

[0005] To achieve the above object, the multi-mode digital valve group hydraulic control system provided by the present invention adopts the following technical solutions:

[0006] A multi-mode digital valve group hydraulic control system includes a pump source, an overflow digital valve group, a first oil tank, a pressure compensation digital valve group, a forward speed regulation digital valve group, a reverse speed regulation digital valve group, a forward pressure regulation digital valve group, a reverse pressure regulation digital valve group, a second oil tank, a shuttle valve, a load, a multi-mode controller, a first pressure sensor, a second pressure sensor, a third pressure sensor, a fourth pressure sensor, and a fifth pressure sensor;

[0007] The pump source is respectively connected to the oil inlets of the overflow digital valve group and the pressure compensation digital valve group; the oil outlet of the overflow digital valve group is connected to the first oil tank; the oil outlet of the pressure compensation digital valve group is respectively connected to the oil inlets of the forward speed regulation digital valve group and the reverse speed regulation digital valve group; the oil outlet of the forward speed regulation digital valve group is respectively connected to the oil inlet of the forward pressure regulation digital valve group and the lower oil port of the load; the oil outlet of the reverse speed regulation digital valve group is respectively connected to the oil inlet of the reverse pressure regulation digital valve group and the upper oil port of the load; the oil outlet of the forward pressure regulation digital valve group is respectively connected to the oil outlet of the reverse pressure regulation digital valve group and the second oil tank; the upper and lower oil ports of the shuttle valve are respectively connected to the upper and lower oil ports of the load;

[0008] The first pressure sensor is arranged at the oil inlet of the overflow digital valve group for measuring the pressure of the system in real time; the second pressure sensor is arranged at the oil outlet of the pressure compensation digital valve group for measuring the pressure of the P port in real time; the third pressure sensor is arranged at the lower oil port of the load for measuring the load pressure of the A port in real time; the fourth pressure sensor is arranged at the upper oil port of the load for measuring the load pressure of the B port in real time; the fifth pressure sensor is arranged at the output oil port of the shuttle valve for measuring the maximum pressure of the load in real time; the signal output ends of the first pressure sensor, the second pressure sensor, the third pressure sensor, the fourth pressure sensor and the fifth pressure sensor are respectively connected to the pressure signal acquisition ends of the multi-mode controller; the multi-mode controller has functions such as constant pressure overflow, multi-function commutation, pressure compensation, speed and force compound control, etc.; the control signal output ends of the multi-mode controller are respectively connected to the control ends of the pressure compensation digital valve group, the forward speed regulation digital valve group, the reverse speed regulation digital valve group, the forward pressure regulation digital valve group and the reverse pressure regulation digital valve group.

[0009] In the present invention, when the pressure compensation digital valve group, the forward speed regulation digital valve group, the reverse speed regulation digital valve group, the forward pressure regulation digital valve group and the reverse pressure regulation digital valve group are all composed of multiple digital valves with binary displacement of output flow in parallel, the multi-mode controller outputs a PCM coding signal to control the operation of each digital valve group; when the pressure compensation digital valve group, the forward speed regulation digital valve group, the reverse speed regulation digital valve group, the forward pressure regulation digital valve group and the reverse pressure regulation digital valve group are all composed of multiple digital valves with equal output flow in parallel, the multi-mode controller outputs a PNM coding signal to control the operation of each digital valve group; when the output flow of the digital valves in the pressure compensation digital valve group, the forward speed regulation digital valve group, the reverse speed regulation digital valve group, the forward pressure regulation digital valve group and the reverse pressure regulation digital valve group is arranged irregularly, the multi-mode controller outputs a PWM signal to control the operation of each digital valve group.

[0010] In addition, the following four functions can be achieved by using the above multi-mode digital valve group hydraulic control system provided by the present invention:

[0011] Constant pressure overflow function: Set the maximum working pressure P0 of the system. The first pressure sensor real-time feedbacks the system pressure P1 and transmits it to the multi-mode controller. The multi-mode controller calculates the duty cycle in real time according to the pressure difference between P0 and P1 by using the proportional differential control algorithm, and further outputs a PWM signal with a variable duty cycle to control the operation of the overflow digital valve group, finally making P1 equal to P0;

[0012] Multi-functional commutation function: When only the overflow digital valve group is fully opened, the M-type function of the spool valve can be achieved, and the pump is in the unloading condition at this time; When the forward speed regulation digital valve group, the reverse speed regulation digital valve group, the forward pressure regulation digital valve group, and the reverse pressure regulation digital valve group are all closed, the O-type function of the spool valve can be achieved, and the load is in the locked position condition at this time; When the forward speed regulation digital valve group, the reverse speed regulation digital valve group, the forward pressure regulation digital valve group, and the reverse pressure regulation digital valve group are all opened, the H-type function of the spool valve can be achieved, and the pump is in the unloading and load floating condition at this time; When only the forward speed regulation digital valve group and the forward pressure regulation digital valve group are fully opened, the C-type function of the spool valve can be achieved, and the load is in the forward movement condition at this time; When only the reverse speed regulation digital valve group and the reverse pressure regulation digital valve group are fully opened, the type function of the spool valve can be achieved, and the load is in the reverse movement condition at this time; When only the forward speed regulation digital valve group and the reverse speed regulation digital valve group are fully opened, the P-type function of the spool valve can be achieved, and the differential movement condition is at this time; When only the forward pressure regulation digital valve group and the reverse pressure regulation digital valve group are fully opened, the Y-type function of the spool valve can be achieved, and the load is in the floating condition at this time;

[0013] Pressure compensation function: The second pressure sensor and the fifth pressure sensor respectively collect the P-port pressure and the maximum load pressure and transmit them to the multi-mode controller. The multi-mode controller calculates the difference between the P-port pressure and the maximum load pressure, subtracts it from the expected value, uses the PID control algorithm to solve the duty cycle in real time, and outputs a PWM signal with a real-time variable duty cycle to drive the pressure compensation digital valve group to work, so that the difference between the P-port pressure and the maximum load pressure remains unchanged, maintaining a constant pressure difference at both ends of the speed regulation digital valve group, making the movement speed not affected by external loads;

[0014] Speed and force composite control function: When the load needs to move forward, the multi-mode controller outputs a PWM signal to control the forward speed regulation digital valve group to work, thereby adjusting the forward movement speed of the load. At the same time, it controls the forward pressure regulation digital valve group to work to adjust the pressure of the upper oil port of the load, thereby controlling the forward output force. When the load needs to move backward, the multi-mode controller outputs a PWM signal to control the reverse speed regulation digital valve group to work, thereby adjusting the reverse movement speed of the load. At the same time, it controls the reverse pressure regulation digital valve group to work to adjust the pressure of the lower oil port of the load, thereby controlling the reverse output force.

[0015] Advantages of the present invention: Compared with the prior art, in the multi-mode digital valve group hydraulic control system of the present invention, traditional hydraulic valves such as pressure, flow, and direction are eliminated, and only digital valves are used to control the system, resulting in low implementation cost; the system functions are transplanted from the hardware level to the software level, and functions such as overflow, pressure compensation, multi-functional commutation, and speed control can be achieved through program programming, with a high degree of intelligence; the digital valve group is composed of multiple digital valves with output flows arranged according to a certain rule in parallel, having high redundancy and fault tolerance; all digital valves in the system can be replaced with each other, with strong versatility and low maintenance cost.

[0016] In summary, the multi-mode digital valve group hydraulic control system proposed by the present invention has the advantages of high intelligence, high reliability, and low cost. Brief Description of the Drawings

[0017] Figure 1 It is a schematic diagram of the multi-mode digital valve group hydraulic control system provided by an embodiment of the present invention;

[0018] Reference numerals in the drawings: 1 - pump source, 2 - overflow digital valve group, 3 - first oil tank, 4 - pressure compensation digital valve group, 5 - forward speed regulation digital valve group, 6 - reverse speed regulation digital valve group, 7 - forward pressure regulation digital valve group, 8 - reverse pressure regulation digital valve group, 9 - second oil tank, 10 - shuttle valve, 11 - load, 12 - multi-mode controller, 13 - first pressure sensor, 14 - second pressure sensor, 15 - third pressure sensor, 16 - fourth pressure sensor, 17 - fifth pressure sensor. Detailed Embodiment

[0019] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0020] As Figure 1As shown in the figure, the device of the present invention mainly includes a pump source 1, an overflow digital valve group 2, a first oil tank 3, a pressure compensation digital valve group 4, a forward speed regulation digital valve group 5, a reverse speed regulation digital valve group 6, a forward pressure regulation digital valve group 7, a reverse pressure regulation digital valve group 8, a second oil tank 9, a shuttle valve 10, a load 11, a multi-mode controller 12, a first pressure sensor 13, a second pressure sensor 14, a third pressure sensor 15, a fourth pressure sensor 16, and a fifth pressure sensor 17;

[0021] The pump source 1 is respectively connected to the oil inlets of the overflow digital valve group 2 and the pressure compensation digital valve group 4; the oil outlet of the overflow digital valve group 2 is connected to the first oil tank 3; the oil outlet of the pressure compensation digital valve group 4 is respectively connected to the oil inlets of the forward speed regulation digital valve group 5 and the reverse speed regulation digital valve group 6; the oil outlet of the forward speed regulation digital valve group 5 is respectively connected to the oil inlet of the forward pressure regulation digital valve group 7 and the lower oil port of the load 11; the oil outlet of the reverse speed regulation digital valve group 6 is respectively connected to the oil inlet of the reverse pressure regulation digital valve group 8 and the upper oil port of the load 11; the oil outlet of the forward pressure regulation digital valve group 7 is respectively connected to the oil outlet of the reverse pressure regulation digital valve group 8 and the second oil tank 9; the upper and lower oil ports of the shuttle valve 10 are respectively connected to the upper and lower oil ports of the load 11;

[0022] The first pressure sensor 13 is arranged at the oil inlet of the overflow digital valve group 2 for measuring the pressure of the system in real time; the second pressure sensor 14 is arranged at the oil outlet of the pressure compensation digital valve group 4 for measuring the pressure of the P port in real time; the third pressure sensor 15 is arranged at the lower oil port of the load 11 for measuring the load pressure of the A port in real time; the fourth pressure sensor 16 is arranged at the upper oil port of the load 11 for measuring the load pressure of the B port in real time; the fifth pressure sensor 17 is arranged at the output oil port of the shuttle valve 10 for measuring the highest pressure of the load in real time; the signal output ends of the first pressure sensor 13, the second pressure sensor 14, the third pressure sensor 15, the fourth pressure sensor 16, and the fifth pressure sensor 17 are respectively connected to the pressure signal acquisition ends of the multi-mode controller 12; the multi-mode controller 12 has functions such as constant pressure overflow, multi-functional commutation, pressure compensation, speed and force compound control, etc.; the control signal output ends of the multi-mode controller 12 are respectively connected to the control ends of the pressure compensation digital valve group 4, the forward speed regulation digital valve group 5, the reverse speed regulation digital valve group 6, the forward pressure regulation digital valve group 7, and the reverse pressure regulation digital valve group 8.

[0023] In this embodiment, when the pressure compensation digital valve group 4, the forward speed regulation digital valve group 5, the reverse speed regulation digital valve group 6, the forward pressure regulation digital valve group 7, and the reverse pressure regulation digital valve group 8 are all composed of multiple digital valves with binary displacement output flow in parallel, the multi-mode controller 12 outputs a PCM encoding signal to control the operation of each digital valve group; when the pressure compensation digital valve group 4, the forward speed regulation digital valve group 5, the reverse speed regulation digital valve group 6, the forward pressure regulation digital valve group 7, and the reverse pressure regulation digital valve group 8 are all composed of multiple digital valves with equal output flow in parallel, the multi-mode controller 12 outputs a PNM encoding signal to control the operation of each digital valve group; when the output flow of the digital valves in the pressure compensation digital valve group 4, the forward speed regulation digital valve group 5, the reverse speed regulation digital valve group 6, the forward pressure regulation digital valve group 7, and the reverse pressure regulation digital valve group 8 is arranged irregularly, the multi-mode controller 12 outputs a PWM signal to control the operation of each digital valve group.

[0024] In this embodiment, the constant pressure overflow function is realized by the following method: set the maximum working pressure P0 of the system, the first pressure sensor 13 continuously feedbacks the system pressure P1 and transmits it to the multi-mode controller 12. The multi-mode controller 12 calculates the duty cycle in real time according to the pressure difference between P0 and P1 by using the proportional derivative control algorithm, and further outputs a PWM signal with variable duty cycle to control the operation of the overflow digital valve group 2, finally making P1 equal to P0.

[0025] In this embodiment, the multi-functional commutation function is realized by the following method: when only the overflow digital valve group 2 is fully opened, the M-type function of the spool can be realized, and at this time, it is in the pump unloading condition; when the forward speed regulation digital valve group 5, the reverse speed regulation digital valve group 6, the forward pressure regulation digital valve group 7, and the reverse pressure regulation digital valve group 8 are all closed, the O-type function of the spool can be realized, and at this time, it is in the load position locking condition; when the forward speed regulation digital valve group 5, the reverse speed regulation digital valve group 6, the forward pressure regulation digital valve group 7, and the reverse pressure regulation digital valve group 8 are all opened, the H-type function of the spool can be realized, and at this time, it is in the pump unloading and load floating condition; when only the forward speed regulation digital valve group 5 and the forward pressure regulation digital valve group 7 are fully opened, the C-type function of the spool can be realized, and at this time, it is in the load forward movement condition; when only the reverse speed regulation digital valve group 6 and the reverse pressure regulation digital valve group 8 are fully opened, the J-type function of the spool can be realized, and at this time, it is in the load reverse movement condition; when only the forward speed regulation digital valve group 5 and the reverse speed regulation digital valve group 6 are fully opened, the P-type function of the spool can be realized, and at this time, it is in the differential movement condition; when only the forward pressure regulation digital valve group 7 and the reverse pressure regulation digital valve group 8 are fully opened, the Y-type function of the spool can be realized, and at this time, it is in the load floating condition.

[0026] In this embodiment, the pressure compensation function is realized by the following method: The second pressure sensor 14 and the fifth pressure sensor 17 respectively collect the pressure of the P port and the maximum load pressure, and transmit them to the multi-mode controller 12. The multi-mode controller 12 calculates the difference between the P port pressure and the maximum load pressure, and subtracts it from the expected value. The duty cycle is solved in real time using the PID control algorithm, and a PWM signal with a variable duty cycle is output to drive the pressure compensation digital valve block 4 to work, so that the difference between the P port pressure and the maximum load pressure remains unchanged, maintaining a constant pressure difference at both ends of the speed control digital valve block, and making the movement speed not affected by external load interference;

[0027] In this embodiment, the speed and force composite control function is realized by the following method: When the load 11 needs to move forward, the multi-mode controller 12 outputs a PWM signal to control the forward speed control digital valve block 5 to work, thereby adjusting the forward movement speed of the load. At the same time, the forward pressure regulating digital valve block 7 is controlled to work to adjust the pressure of the upper oil port of the load 11, thereby controlling the forward output force; When the load 11 needs to move backward, the multi-mode controller 12 outputs a PWM signal to control the reverse speed control digital valve block 6 to work, thereby adjusting the reverse movement speed of the load. At the same time, the reverse pressure regulating digital valve block 8 is controlled to work to adjust the pressure of the lower oil port of the load 11, thereby controlling the reverse output force.

[0028] Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Those with ordinary knowledge in the technical field to which the present invention pertains can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the scope defined in the claims.

Claims

1. A multi-mode digital valve group hydraulic control system, characterized by: It includes a pump source, a overflow digital valve group, a first oil tank, a pressure compensation digital valve group, a forward speed regulation digital valve group, a reverse speed regulation digital valve group, a forward pressure regulation digital valve group, a reverse pressure regulation digital valve group, a second oil tank, a shuttle valve, a load, a multi-mode controller, a first pressure sensor, a second pressure sensor, a third pressure sensor, a fourth pressure sensor, and a fifth pressure sensor; The pump source is communicated with the oil inlets of the overflow digital valve group and the pressure compensation digital valve group respectively; the oil outlet of the overflow digital valve group is communicated with the first oil tank; the oil outlet of the pressure compensation digital valve group is communicated with the oil inlets of the forward speed regulation digital valve group and the reverse speed regulation digital valve group respectively; the oil outlet of the forward speed regulation digital valve group is communicated with the oil inlet of the forward pressure regulation digital valve group and the lower oil port of the load respectively; the oil outlet of the reverse speed regulation digital valve group is communicated with the oil inlet of the reverse pressure regulation digital valve group and the upper oil port of the load respectively; the oil outlet of the forward pressure regulation digital valve group is communicated with the oil outlet of the reverse pressure regulation digital valve group and the second oil tank respectively; the upper and lower oil ports of the shuttle valve are communicated with the upper and lower oil ports of the load respectively; The first pressure sensor is arranged at the oil inlet of the overflow digital valve group for real-time measurement of the system pressure; the second pressure sensor is arranged at the oil outlet of the pressure compensation digital valve group for real-time measurement of the pressure of port P; the third pressure sensor is arranged at the lower oil port of the load for real-time measurement of the load pressure of port A; the fourth pressure sensor is arranged at the upper oil port of the load for real-time measurement of the load pressure of port B; the fifth pressure sensor is arranged at the output oil port of the shuttle valve for real-time measurement of the maximum pressure of the load; the signal output ends of the first pressure sensor, the second pressure sensor, the third pressure sensor, the fourth pressure sensor, and the fifth pressure sensor are respectively connected to the pressure signal acquisition end of the multi-mode controller; the multi-mode controller has pressure-stabilizing overflow, multi-function reversing, pressure compensation, speed and force composite control; the control signal output end of the multi-mode controller is respectively connected to the control ends of the pressure compensation digital valve group, the forward speed regulation digital valve group, the reverse speed regulation digital valve group, the forward pressure regulation digital valve group, and the reverse pressure regulation digital valve group.

2. The multi-mode digital valve group hydraulic control system according to claim 1, characterized in that: When the pressure-compensating digital valve group, the forward speed-regulating digital valve group, the reverse speed-regulating digital valve group, the forward pressure-regulating digital valve group, and the reverse pressure-regulating digital valve group are all composed of a plurality of digital valves with binary displacement output flows connected in parallel, the multi-mode controller outputs a PCM coding signal to control the operation of each digital valve group; when the pressure-compensating digital valve group, the forward speed-regulating digital valve group, the reverse speed-regulating digital valve group, the forward pressure-regulating digital valve group, and the reverse pressure-regulating digital valve group are all composed of a plurality of digital valves with equal output flows connected in parallel, the multi-mode controller outputs a PNM coding signal to control the operation of each digital valve group; when the output flows of the digital valves in the pressure-compensating digital valve group, the forward speed-regulating digital valve group, the reverse speed-regulating digital valve group, the forward pressure-regulating digital valve group, and the reverse pressure-regulating digital valve group are arranged irregularly, the multi-mode controller outputs a PWM signal to control the operation of each digital valve group.

3. The multi-function implementation method of the multi-mode digital valve group hydraulic control system according to claim 1 is characterized in that: It includes the following four functions: Pressure stabilization and overflow function: Set the system's maximum operating pressure P0. The first pressure sensor provides real-time feedback of the system pressure P1 and transmits it to the multi-mode controller. The multi-mode controller calculates the duty cycle in real time based on the pressure difference between P0 and P1 using the proportional-differential control algorithm, and further outputs a PWM signal with a variable duty cycle to control the operation of the overflow digital valve group, ultimately making P1 equal to P0. Multi-function reversing function: when only the overflow digital valve group is fully opened, the slide valve M-type function is realized, and the pump is in the unloading working condition at this time; when the forward speed control digital valve group, the reverse speed control digital valve group, the forward pressure control digital valve group, and the reverse pressure control digital valve group are all closed, the slide valve O-type function is realized, and the load position is locked at this time; when the forward speed control digital valve group, the reverse speed control digital valve group, the forward pressure control digital valve group, and the reverse pressure control digital valve group are all opened, the slide valve H-type function is realized, and the pump is in the unloading and load floating working condition at this time; when only the forward speed control digital valve group When the digital valve group and the forward pressure regulating digital valve group are fully opened, the slide valve C-type function is realized, and the load is in the forward motion condition; when only the reverse speed regulating digital valve group and the reverse pressure regulating digital valve group are fully opened, the slide valve type function is realized, and the load is in the reverse motion condition; when only the forward speed regulating digital valve group and the reverse speed regulating digital valve group are fully opened, the slide valve P-type function is realized, and the load is in the differential motion condition; when only the forward pressure regulating digital valve group and the reverse pressure regulating digital valve group are fully opened, the slide valve Y-type function is realized, and the load is in the floating condition; Pressure compensation function: The second and fifth pressure sensors collect the P-port pressure and the maximum load pressure, respectively, and transmit them to the multi-mode controller. The multi-mode controller calculates the difference between the P-port pressure and the maximum load pressure, subtracts it from the expected value, uses the PID control algorithm to solve the duty cycle in real time, and outputs a PWM signal with a real-time variable duty cycle to drive the pressure compensation digital valve group to operate, so that the difference between the P-port pressure and the maximum load pressure remains unchanged, maintaining a constant pressure differential across the speed-regulating digital valve group, and preventing the movement speed from being affected by external load interference; Speed and force composite control function: When the load needs to move forward, the multi-mode controller outputs a PWM signal to control the forward speed regulation digital valve group to work, thereby adjusting the forward movement speed of the load, and at the same time controls the forward pressure regulation digital valve group to work to adjust the upper end oil port pressure of the load, thereby controlling the forward output force; when the load needs to move in the reverse direction, the multi-mode controller outputs a PWM signal to control the reverse speed regulation digital valve group to work, thereby adjusting the reverse movement speed of the load, and at the same time controls the reverse pressure regulation digital valve group to work to adjust the lower end oil port pressure of the load, thereby controlling the reverse output force.

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