Industrial vehicle micro-motion control system and control method

Abstract

The present application discloses an industrial vehicle micro-motion control system and control method, the industrial vehicle micro-motion control system comprises a micro-motion proportional valve, a brake assembly, a hydraulic clutch connected to the micro-motion proportional valve, a vehicle speed sensor for detecting the vehicle travel speed, a displacement sensor for detecting the position of the micro-motion pedal and generating a position signal, a pressure sensor for detecting the oil pressure at the hydraulic clutch, and a micro-motion controller; the micro-motion controller is connected to the displacement sensor, the vehicle speed sensor, the pressure sensor, the micro-motion proportional valve and the brake assembly, the micro-motion controller is used to control the micro-motion proportional valve to adjust the hydraulic clutch according to the position signal of the displacement sensor when the travel speed is less than a preset speed, and control the brake assembly to brake when the oil pressure at the hydraulic clutch reaches a preset pressure. The above industrial vehicle micro-motion control system can accurately control the micro-motion and brake linkage clearance, and improve the micro-motion control accuracy.

Description

Technical Field

[0001] The present application relates to the field of industrial vehicles, and in particular to an industrial vehicle micro-motion control system and a control method. Background Art

[0002] When a forklift is loading and unloading, it is necessary to accurately place the forks under the cargo, and the vehicle cannot bump into the cargo. At the same time, the cargo must be placed in a specified place. This requires the forklift to slowly and accurately approach the cargo or the specified place. That is, the operating characteristics of the forklift determine that the forklift often needs to adjust the position of the forklift within a small range during operation, that is, to make micro-movements, and the micro-movement accuracy may even need to reach 1mm.

[0003] When the forklift is in use, the inching pedal is stepped on, and the inching valve controls the partial unloading of the pressure oil flowing into the hydraulic clutch, so that the oil pressure on the piston surface of the hydraulic clutch is reduced, causing slippage, so that the forklift can move slowly, so as to achieve the purpose of accurately controlling the travel of the forklift. Whether it is the inching valve of the above-mentioned hydraulic transmission internal combustion counterbalanced forklift or the clutch of the mechanical transmission internal combustion counterbalanced forklift, not only will the long-term inching cause the clutch to wear too quickly and burn out, but the inching brake operation linkage clearance needs to be manually adjusted, and braking too quickly or too slowly will affect the inching brake accuracy, resulting in inaccurate inching function and failure to brake in time.

[0004] Therefore, how to improve the micro-motion control accuracy of industrial vehicles becomes a technical problem that needs to be solved by those skilled in the art. Summary of the invention

[0005] The purpose of the present application is to provide an industrial vehicle micro-motion control system, which can improve micro-motion control accuracy. Another purpose of the present application is to provide a control method applied to the industrial vehicle micro-motion control system.

[0006] To achieve the above-mentioned object, the present application provides an industrial vehicle inching control system, comprising an inching proportional valve, a brake assembly, a hydraulic clutch connected to the inching proportional valve, a vehicle speed sensor for detecting the vehicle travel speed, a displacement sensor for detecting the position of an inching pedal and generating a position signal, a pressure sensor for detecting the oil pressure at the hydraulic clutch, and an inching controller;

[0007] The micro-controller is connected to the displacement sensor, the vehicle speed sensor, the pressure sensor, the micro-proportional valve and the brake assembly. The micro-controller is used to control the micro-proportional valve to adjust the hydraulic clutch according to the position signal of the displacement sensor when the travel speed is less than a preset speed, and control the braking assembly to brake when the oil pressure at the hydraulic clutch reaches a preset pressure.

[0008] Optionally, the preset pressure is 3.5MPa-4MPa, and the preset speed is 5km / h.

[0009] Optionally, the brake assembly includes a brake proportional valve connected to the micro-controller and a brake connected to the brake proportional valve.

[0010] Optionally, the micro-controller is connected to the shift solenoid valve and also includes a temperature sensor for detecting the temperature of the hydraulic clutch. The temperature sensor is connected to the micro-controller. The micro-controller controls the shift solenoid valve to switch to N gear when the temperature of the hydraulic clutch exceeds a preset temperature.

[0011] Optionally, the micro-controller is connected to the engine, and the micro-controller is used to control the engine to slow down when the travel speed is greater than a preset speed, and control the brake assembly to brake.

[0012] The present application provides a control method, which is applied to the above-mentioned industrial vehicle micro-motion control system, comprising:

[0013] receiving position information of an inching pedal and activating the inching control system;

[0014] Detect and determine the vehicle's traveling speed and the preset speed;

[0015] If the travel speed is less than a preset speed, the inching proportional valve is controlled according to the position information to adjust the hydraulic clutch to achieve inching of the vehicle;

[0016] If the traveling speed is greater than a preset speed, the traveling speed is reduced and the step of detecting the traveling speed of the vehicle is performed again;

[0017] The oil pressure at the hydraulic clutch is detected, and when the oil pressure reaches a preset pressure, the vehicle brake is subjected to inching and brake linkage control.

[0018] Optionally, the step of reducing the travel speed comprises:

[0019] Reduce engine speed;

[0020] Brake the vehicle.

[0021] Optionally, the method further includes detecting the temperature of the hydraulic clutch, and when the temperature of the hydraulic clutch exceeds a preset temperature, controlling the engine to idle and switching the vehicle to N gear.

[0022] The micro-motion control system provided by the present application detects the travel speed of an industrial vehicle such as an internal combustion forklift, and performs micro-motion at a low speed lower than a preset speed, so as to achieve high-precision micro-motion control; the micro-motion of the vehicle is achieved by a controller controlling a hydraulic clutch according to the position information of the micro-motion pedal; braking is achieved by a micro-motion controller controlling a brake assembly; at the same time, the micro-motion controller uses the oil pressure at the hydraulic clutch as the basis for the brake assembly to brake, and when the oil pressure reaches the preset pressure, the micro-motion controller controls the brake assembly to brake automatically, without the need for manual control of the micro-motion and brake clearances, and accurately controls the linkage process of the micro-motion function and the brake function, thereby improving the micro-motion control accuracy of the industrial vehicle.

[0023] In a further embodiment, the micro-motion controller flexibly controls the starting working time of the micro-motion proportional valve according to the vehicle speed, thereby reducing the wear of the hydraulic clutch; by detecting the temperature at the hydraulic clutch, the micro-motion time is controlled to avoid long-term clutch wear and plate burning, thereby ensuring the normal operation of the micro-motion function. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present application 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 embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0025] Figure 1 A schematic diagram of a micro-motion control system provided in an embodiment of the present application;

[0026] Figure 2 A flow chart of a control method provided in an embodiment of the present application.

[0027] in:

[0028] 1- micro controller, 2- displacement sensor, 3- vehicle speed sensor, 4- temperature sensor, 5- pressure sensor, 6- micro proportional valve, 7- hydraulic clutch, 8- engine, 9- brake proportional valve, 10- brake, 11- shift solenoid valve. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0030] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0031] Please refer to Figure 1 The embodiment of the present application provides an industrial vehicle micro-motion control system, which can improve the micro-motion control accuracy of industrial vehicles such as internal combustion forklifts. The micro-motion control system mainly includes a micro-motion controller 1, a displacement sensor 2, a pressure sensor 5, a vehicle speed sensor 3, a micro-motion control valve, a hydraulic clutch 7 and a brake assembly, and the displacement sensor 2, the pressure sensor 5, the vehicle speed sensor 3, the micro-motion control valve, the hydraulic clutch 7 and the brake assembly are all connected to the micro-motion controller 1. Among them, the displacement sensor 2 is used to detect the vehicle's traveling speed so that the micro-control operation can be performed only when the traveling speed is less than the preset speed; the displacement sensor 2 is used to be set at the micro-pedal, and a position signal about the micro-pedal is generated by detecting the displacement of the micro-pedal, and the position signal is transmitted to the micro-controller 1 to activate the micro-control system, and at the same time, it is convenient for the micro-controller 1 to control the opening of the micro-proportional valve 6 according to the position signal, and adjust the hydraulic clutch 7 to realize the micro-function; the brake assembly is used to realize braking under the control of the micro-controller 1, and the pressure sensor 5 is used to detect the oil pressure at the hydraulic clutch 7, and feedback is given to the micro-controller 1 when the oil pressure reaches the set oil pressure. The micro-controller 1 controls the brake assembly to realize the braking function, automatically controls the time gap between micro-movement and braking, brakes in time and accurately, and uses the micro-controller 1 to realize precise linkage and improve the micro-control accuracy.

[0032] In this embodiment, the preset pressure is usually set at 3.5MPa-4MPa. It should be noted that the preset pressure can be adjusted according to factors such as the vehicle model, micro-control accuracy, and the model of the hydraulic clutch 7. In order to ensure the micro-control accuracy, the micro-controller 1 controls the micro-control proportional valve 6 for micro-control only when the travel speed is less than 5km / h. The brake assembly specifically adopts a brake proportional valve 9 and a brake 10 connected to the brake proportional valve 9. The brake proportional valve 9 is connected to the micro-controller 1. The micro-controller 1 controls the brake proportional valve 9 to adjust the brake 10 to achieve timely braking.

[0033] In one embodiment, the micro-controller 1 is connected to the engine 8 and the shift solenoid valve 11, and the micro-control system further includes a temperature sensor 4 for detecting the temperature of the hydraulic clutch 7. The temperature sensor 4 is used to detect the temperature of the hydraulic clutch 7 and feed back to the micro-controller 1 in real time. When the temperature of the hydraulic clutch 7 exceeds the preset temperature, the micro-controller 1 controls the engine 8 to switch to the idle state, and the shift solenoid valve 11 switches to the N gear, that is, the neutral gear state, so that the hydraulic clutch 7 is in a disengaged non-working state and cools down quickly, so as to avoid the wear and even burning of the hydraulic clutch 7 due to the long micro-motion time, and ensure the micro-motion function. When the temperature of the hydraulic clutch 7 exceeds the set temperature, the micro-controller 1 simultaneously controls the micro-proportional valve 6 to output the brake pressure to the brake 10, so as to reduce the vehicle speed and ensure driving safety.

[0034] The inching controller 1 responds to the inching pedal action and performs the inching control operation only when the travel speed is lower than the preset speed. When the travel speed exceeds the preset speed, the inching controller 1 controls the brake assembly to brake, and controls the engine 8 to run at idle speed, and responds to perform the inching control operation after the travel speed is reduced to below the preset speed.

[0035] The present application embodiment provides a control method, which is applied to the industrial vehicle micro-motion control system provided in the above embodiment, referring to Figure 2 , the control method comprises the following steps:

[0036] Step S100: receiving the position information of the inching pedal and activating the inching control system;

[0037] Step S200: Detecting and determining the magnitude of the vehicle's traveling speed and a preset speed;

[0038] Step S310: if the travel speed is less than the preset speed, the inching proportional valve 6 is controlled to adjust the hydraulic clutch 7 according to the position information to realize the inching of the vehicle;

[0039] Step S320: if the travel speed is greater than the preset speed, the travel speed is reduced and the step of detecting the travel speed of the vehicle is performed again;

[0040] Step S400: Detect the oil pressure at the hydraulic clutch 7, and when the oil pressure reaches a preset pressure, implement inching and brake linkage control on the vehicle brake.

[0041] Step S100 specifically involves the driver stepping on the inching pedal, the displacement sensor 2 at the inching pedal moves with the inching pedal, calculates the stepping depth of the inching pedal, and generates an electrical signal reflecting the position information of the inching pedal. The electrical signal is sent to the inching controller 1, and the inching control system is activated.

[0042] Step S200 specifically uses the vehicle speed sensor 3 to collect the vehicle's travel speed in real time. The vehicle speed sensor 3 sends the real-time detected travel speed to the micro-controller 1, and compares it with the preset speed stored in the micro-controller 1. In this embodiment, the preset speed is set to 5km / h. It is worth mentioning that the preset speed can be adjusted as needed and stored in the micro-controller 1.

[0043] Step S310, if the vehicle's traveling speed is less than the preset speed, the micro-controller 1 controls the opening of the micro-control valve according to the micro-pedal position information detected by the displacement sensor 2, adjusts the hydraulic clutch 7, and reduces the oil pressure on the piston surface of the hydraulic clutch 7, causing slippage to achieve vehicle micro-motion.

[0044] Then, step S400 is executed to detect the oil pressure at the hydraulic clutch 7. When the oil pressure reaches a preset pressure between 3.5MPa and 4.0MPa, the micro-controller 1 controls the brake proportional valve 9, and the brake proportional valve 9 outputs the brake pressure to the brake 10, and the linkage control is realized to realize micro-motion precise control.

[0045] In step S320, if the vehicle's travel speed is higher than the preset speed, the travel speed is reduced and then the process returns to step S200, until the travel speed is lower than the preset speed, and then steps S310 and S400 are sequentially executed. The travel speed is reduced by the micro-controller 1 controlling the micro-proportional valve 6 to output the brake pressure to the brake 10, and the brake 10 is used to brake and decelerate; in addition, the micro-controller 1 can also directly act on the engine 8 to control the engine 8 to decelerate, and the dual measures can quickly reduce the vehicle speed.

[0046] In a further embodiment, when performing the micro-control operation, it also includes detecting the temperature at the hydraulic clutch 7. After the micro-control system is activated, the step of detecting the temperature of the hydraulic clutch 7 and the step of detecting the driving speed are executed synchronously. The micro-controller 1 collects the temperature signal of the temperature sensor 4 to judge the temperature of the hydraulic clutch 7. When the temperature of the hydraulic clutch 7 is lower than the preset temperature and the driving speed is lower than the preset speed, the micro-controller 1 is allowed to execute the micro-control operation. If the temperature of the hydraulic clutch 7 is higher than the preset temperature, the engine 8 is controlled to idle with the help of the micro-controller 1, and the shift solenoid valve 11 is used to switch the vehicle to N gear (neutral state) to quickly cool down the hydraulic clutch 7.

[0047] It should be noted that the step of detecting the temperature of the hydraulic clutch 7 runs through the entire micro-motion control process. Before the micro-motion controller 1 performs the micro-motion control operation, if the temperature of the hydraulic clutch 7 exceeds the preset temperature, the micro-motion control operation cannot be continued; during the micro-motion control operation, if the temperature of the hydraulic clutch 7 rises to a temperature exceeding the preset temperature as the micro-motion time increases, the micro-motion controller 1 controls the engine 8 to run at idle speed, and uses the shift solenoid valve 11 to switch the vehicle to the N gear (neutral state), and controls the brake proportional valve 9 to output the brake pressure to the brake 10 to ensure driving safety. Avoid excessive micro-motion time to prevent the clutch from wearing or even burning, and ensure the micro-motion function and micro-motion control accuracy.

[0048] It should be noted that, in this specification, relational terms such as first and second are only used to distinguish one entity from other entities, and do not necessarily require or imply any actual relationship or order between these entities. In the above, industrial vehicle / vehicle / internal combustion forklift refers to the target entity used to implement micro-motion control.

[0049] The above is a detailed introduction to the industrial vehicle micro-motion control system and control method provided by the present application. This article uses specific examples to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core ideas of the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. An industrial vehicle micro-motion control system, characterized in that: It includes an inching proportional valve, a brake assembly, a hydraulic clutch connected to the inching proportional valve, a vehicle speed sensor for detecting the vehicle's travel speed, a displacement sensor for detecting the position of an inching pedal and generating a position signal, a pressure sensor for detecting the oil pressure at the hydraulic clutch, and an inching controller; The micro-controller is connected to the displacement sensor, the vehicle speed sensor, the pressure sensor, the micro-proportional valve and the brake assembly. The micro-controller is used to control the micro-proportional valve to adjust the hydraulic clutch according to the position signal of the displacement sensor when the travel speed is less than the preset speed, and control the brake assembly to brake when the oil pressure at the hydraulic clutch reaches the preset pressure; The micro-controller is connected to the engine and the shift solenoid valve, and the micro-control system also includes a temperature sensor for detecting the temperature of the hydraulic clutch, and the temperature sensor is used to detect the temperature of the hydraulic clutch and provide real-time feedback to the micro-controller; before the micro-controller performs the micro-control operation, if the temperature of the hydraulic clutch exceeds a preset temperature, the micro-controller cannot continue to perform the micro-control operation; during the micro-control operation, when the temperature of the hydraulic clutch exceeds the preset temperature, the micro-controller controls the engine to switch to the idle state, and the shift solenoid valve switches to the N gear at the same time; When the travel speed exceeds the preset speed, the inching controller controls the brake assembly to brake and controls the engine to run at idle speed, and responds to perform inching control operations after reducing the travel speed to below the preset speed.

2. The industrial vehicle micro-motion control system according to claim 1, characterized in that: The preset pressure is 3.5MPa-4MPa, and the preset speed is 5km / h.

3. The industrial vehicle micro-motion control system according to claim 1, characterized in that: The brake assembly comprises a brake proportional valve connected to the micro-controller and a brake connected to the brake proportional valve.

4. A control method, characterized in that: The industrial vehicle micro-motion control system applied to any one of claims 1 to 3 comprises: receiving position information of an inching pedal and activating the inching control system; Detect and determine the vehicle's traveling speed and the preset speed; If the travel speed is less than the preset speed, the inching proportional valve is controlled according to the position information to adjust the hydraulic clutch to realize the inching of the vehicle; If the traveling speed is greater than the preset speed, the traveling speed is reduced and the step of detecting the traveling speed of the vehicle is performed again; Detecting the oil pressure at the hydraulic clutch, and implementing inching and brake linkage control on the vehicle brake when the oil pressure reaches a preset pressure; The micro-controller is connected to the engine and the shift solenoid valve, and the micro-control system further comprises a temperature sensor for detecting the temperature of the hydraulic clutch, wherein the temperature sensor is used to detect the temperature of the hydraulic clutch and provide real-time feedback to the micro-controller; before the micro-controller performs the micro-control operation, if the temperature of the hydraulic clutch exceeds a preset temperature, the micro-controller cannot continue to perform the micro-control operation; during the micro-control operation, when the temperature of the hydraulic clutch exceeds the preset temperature, the micro-controller controls the engine to switch to the idle state, and at the same time the shift solenoid valve switches to the N gear; When the travel speed exceeds the preset speed, the inching controller controls the brake assembly to brake and controls the engine to run at idle speed, and responds to perform inching control operations after reducing the travel speed to below the preset speed.

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