Loader drive axle differential lock control method

Abstract

The invention relates to a loader drive axle differential lock control method which specifically comprises the steps that a differential lock switch is arranged on a differential lock of a drive axle on a loader, a manual mode of the differential lock is started through the differential lock switch, the differential lock is kept to be opened within set holding time after starting, and after the time is over, the differential lock enters an automatic mode of the differential lock. Opening and closing of the differential lock are determined by the control unit according to judgment conditions, the differential lock switch is pressed down again within the holding time set by the manual mode of the differential lock, the manual mode is quitted, and the automatic mode of the differential lock is directly entered; when the vehicle enters the automatic differential lock mode, the running states of the vehicle are judged to be the straight running state, the left steering state and the right steering state, the differential lock is opened or closed through judgment conditions in all the running states, whether the differential lock needs to be opened or not can be automatically determined according to the running states of the vehicle, and the control mode is more accurate.

Description

Technical Field

[0001] The invention relates to the technical field of loaders, in particular to a method for controlling a differential lock of a loader drive axle. Background Art

[0002] The drive axle of the loader is equipped with a differential, which can make the tires on the left and right sides rotate at different speeds during operation. Under harsh road conditions, one side of the tire will slip and spin, and the vehicle will lose power. The drive axle with a differential lock function can lock the differential using the differential lock, so that the tires on the left and right sides rotate at the same speed, avoiding one-sided slipping and vehicle power loss.

[0003] Currently, the application of differential locks in engineering machinery is gradually increasing, but the control of differential locks is mostly mechanical control, or the gearbox has a differential lock function, and the dedicated oil port of the gearbox is connected to the drive axle for electronic control. It is not possible to better realize the opening and closing control of the differential lock according to the driving state of the vehicle, and there are certain limitations on the application of differential locks. Summary of the invention

[0004] In order to overcome the above-mentioned deficiencies in the prior art, the present invention seeks to provide a method for controlling a differential lock of a loader drive axle, which can better control the opening and closing of the differential lock according to the driving state of the vehicle.

[0005] The technical solution adopted by the present invention to solve the technical problem is:

[0006] A loader drive axle differential lock control method, characterized in that it specifically includes:

[0007] (1) The differential lock of the drive axle on the loader is provided with a differential lock switch, which is connected to the control unit. The differential lock is turned on and off by the control unit. The differential lock manual mode is turned on by the differential lock switch. After turning on, the differential lock is kept on for a set holding time. After the time is over, the differential lock automatic mode is entered. The control unit determines the opening and closing of the differential lock according to the judgment conditions. Within the holding time set in the differential lock manual mode, if the differential lock switch is pressed again, the manual mode is exited and the differential lock automatic mode is directly entered.

[0008] (2) When the differential lock automatic mode is entered, the vehicle's driving state is detected by the vehicle's angle sensor, and the vehicle's driving state is determined as "straight ahead", "left turn" or "right turn";

[0009] (3) A preset value of the speed difference between the left and right tires of the driving axle in the straight-ahead state is set. In the "straight-ahead state" of the differential lock automatic mode, the speed of the left tire of the driving axle is detected by the left wheel speed sensor on the same driving axle, and the speed of the right tire of the driving axle is detected by the right wheel speed sensor. When the absolute value of the speed difference between the left and right tires is less than or equal to the set value of the speed difference between the left and right tires in the straight-ahead state, the differential lock is closed; when the absolute value of the speed difference between the left and right tires is greater than the set value of the speed difference between the left and right tires in the straight-ahead state, the differential lock is opened;

[0010] (4) A preset left-turn state left- and right-tire speed difference setting value of the drive axle is set. In the "left-turn state" of the differential lock automatic mode, the left wheel speed sensor on the same drive axle detects the speed of the left tire of the drive axle, and the right wheel speed sensor detects the speed of the right tire of the drive axle. When the speed of the left tire is greater than the speed of the right tire, the differential lock is turned on; when the difference between the speed of the right tire and the speed of the left tire is less than or equal to the left-turn state left- and right-tire speed difference setting value, the differential lock is turned off; when the difference between the speed of the right tire and the speed of the left tire is greater than the left- and right-tire speed difference setting value in the left-turn state, the differential lock function is turned on;

[0011] (5) A setting value of the speed difference between the left and right tires in the right-steering state of the drive axle is preset. In the "right-steering state" of the differential lock automatic mode, the speed of the left tire of the drive axle is detected by the left wheel speed sensor on the same drive axle, and the speed of the right tire of the drive axle is detected by the right wheel speed sensor. When the speed of the right tire is greater than the speed of the left tire, the differential lock is turned on; when the difference between the speeds of the left tire and the right tire is less than or equal to the setting value of the speed difference between the left and right tires in the right-steering state, the differential lock is turned off; when the difference between the speeds of the left tire and the right tire is greater than the setting value of the speed difference between the left and right tires in the right-steering state, the differential lock is turned on.

[0012] Preferably, the drive axle is a front-wheel drive axle, a rear-wheel drive axle, or a front- and rear-wheel drive axle.

[0013] Preferably, when the drive axle is a front-wheel drive axle or a rear-wheel drive axle, the differential locks of the front-wheel drive axle and the rear-wheel drive axle are both provided with differential lock switches and are independently controlled.

[0014] Preferably, the control unit controls the on and off of the differential lock hydraulic oil by controlling a proportional solenoid valve.

[0015] Preferably, the control unit is connected to a display and parameter setting device for displaying the actual state of the differential lock output by the control unit and capable of adjusting parameter values.

[0016] Preferably, the loader is provided with rotation speed sensors on the front two wheels, the rear two wheels or the front and rear four wheels.

[0017] Preferably, the differential lock is connected to a pressure sensor, a pressure value of the drive axle differential lock system is preset, the pressure sensor is connected to the control unit (5), and the differential lock system pressure is detected in real time. The control unit determines the opening and closing state of the differential lock through the signal collected by the pressure sensor. If the differential lock system pressure is greater than the differential lock set pressure value, the differential lock is in the closed state.

[0018] Beneficial effects:

[0019] Compared with the prior art, the loader drive axle differential lock control method of the present invention has the following beneficial effects:

[0020] (1) The present invention can automatically determine whether the differential lock needs to be opened according to the driving state of the vehicle, and the control method is more accurate.

[0021] (2) The present invention adopts a proportional solenoid valve to control the differential lock, and there is no need to specially consider the source of the hydraulic oil source. The system pressure required by the differential lock can be matched through the program. The application range is wider, and there is a pressure feedback signal, which can prevent the differential lock from being damaged by excessive pressure, and can determine whether the differential lock is in the open state.

[0022] (3) The present invention can conveniently adjust the judgment value through the display and parameter setting device and can be applied to loaders of different models.

[0023] (4) The present invention can be used for the front drive axle or the rear drive alone, or can control the front drive axle and the rear drive at the same time, and has flexible application. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0025] Figure 1 is a control principle diagram of a differential lock of a loader drive axle according to an embodiment of the present invention;

[0026] Figure 2 1. is a control flow chart of a manual mode of a front drive axle differential lock of a loader drive axle differential lock according to an embodiment of the present invention;

[0027] Figure 3 is a control flow chart of the automatic mode of the front drive axle differential lock of the loader drive axle differential lock according to an embodiment of the present invention;

[0028] In the figure: 11, front drive proportional solenoid valve, 12, rear drive proportional solenoid valve, 21, front drive axle with differential lock function, 22, rear drive axle with differential lock function, 31, front drive pressure sensor, 32, rear drive pressure sensor, 41, front drive left wheel speed sensor, 42, front drive right wheel speed sensor, 43, rear drive left wheel speed sensor, 44, rear drive right wheel speed sensor, 5, control unit, 6, angle sensor, 71, front drive differential lock switch, 72, rear drive differential lock switch, 8, display and parameter setting device. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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.

[0030] Embodiment 1:

[0031] Combination Figure 1 As shown, this embodiment provides a system schematic diagram corresponding to a method for controlling a differential lock of a front-rear drive loader drive axle. The loader drive axle differential control system includes: Figure 1 The related connections shown include a front drive proportional solenoid valve 11, a rear drive proportional solenoid valve 12, a front drive axle 21 with a differential lock function, a rear drive axle 22 with a differential lock function, a front drive pressure sensor 31, a rear drive pressure sensor 32, a front drive left wheel speed sensor 41, a front drive right wheel speed sensor 42, a rear drive left wheel speed sensor 43, a rear drive right wheel speed sensor 44, a control unit 5, an angle sensor 6, a front drive differential lock switch 71, a rear drive differential lock switch 72, and a display and parameter setting device 8.

[0032] In this embodiment, the front drive proportional solenoid valve 11, the rear drive proportional solenoid valve 12, the front drive axle 21 with differential lock function, the rear drive axle 22 with differential lock function, the front drive pressure sensor 31, the rear drive pressure sensor 32, the front drive left wheel speed sensor 41, the front drive right wheel speed sensor 42, the rear drive left wheel speed sensor 43, the rear drive right wheel speed sensor 44, the control unit 5, the angle sensor 6, the front drive differential lock switch 71, the rear drive differential lock switch 72, and the display and parameter setting device 8 all adopt existing products or structures well known to those skilled in the art, and the related connection methods also adopt existing connection methods well known to those skilled in the art, which will not be described in detail herein.

[0033] The front drive proportional solenoid valve 11 and the rear drive proportional solenoid valve 12 are used to control the on / off and pressure of the hydraulic oil of the differential lock. The pressure is determined by the control unit 5 according to the system pressure required by the differential lock used, and is achieved by controlling the maximum current of the proportional solenoid valve. The angle sensor 6 detects the steering angle of the vehicle, the front drive left wheel speed sensor 41 detects the speed of the left tire of the front drive axle, the front drive right wheel speed sensor 42 detects the speed of the right tire of the front drive axle, and the front drive differential lock switch 71 is used to control the manual mode of the front drive axle differential lock on and off; the front drive pressure sensor 31 detects the actual system pressure of the differential lock and feeds it back to the control unit 5, the rear drive left wheel speed sensor 43 detects the speed of the left tire of the rear drive axle, the rear drive right wheel speed sensor 44 detects the speed of the right tire of the rear drive axle, and the rear drive differential lock switch 72 is used to control the manual mode of the rear drive axle differential lock on and off; the rear drive pressure sensor 32 detects the actual system pressure of the differential lock and feeds it back to the control unit 5 for the conditions for closing the differential lock function and for displaying and reminding the differential lock status. The control unit 5 receives signals from the front drive pressure sensor 31, the rear drive pressure sensor 32, the front drive left wheel speed sensor 41, the front drive right wheel speed sensor 42, the rear drive left wheel speed sensor 43, the rear drive right wheel speed sensor 44, and the angle sensor 6, and determines and controls the on and off of the front drive proportional solenoid valve 11 and the rear drive proportional solenoid valve 12 to realize the opening and closing of the differential lock function;

[0034] Figure 2-3 This is the differential lock control flow of the front drive axle 21 with a differential lock function in this example.

[0035] The differential lock of the rear drive axle 22 with a differential lock function and the differential lock of the front drive axle 21 with a differential lock function in this example are controlled independently.

[0036] The control method of the differential lock of the rear drive axle 22 with a differential lock function in this example is the same as the control method of the differential lock of the front drive axle 21 with a differential lock function.

[0037] Combination Figure 2 As shown, the manual mode control flow chart of the front drive axle differential lock of the loader drive axle differential lock is shown. First, the values ​​or ranges of "straight-ahead angle range setting value", "straight-ahead left and right tire speed difference setting value", "steering state left and right tire speed difference setting value", and "manual differential lock holding time setting value" need to be given.

[0038] The front drive differential lock switch 71, the control unit 5 receives the opening signal, the control unit 5 outputs a signal to control the proportional solenoid valve 11 to change direction, the hydraulic oil flows to the front drive axle, the front drive axle differential lock function is turned on, and the front drive axle differential lock manual mode is entered. After turning on, the differential lock is kept on for the set holding time, and after the time is over, the differential lock automatic mode is entered. Within the holding time set in the differential lock manual mode, if the front drive differential lock switch 71 is pressed again, the differential lock automatic mode is directly entered.

[0039] Combination Figure 3 As shown, the automatic mode control flow chart of the front drive axle differential lock of the loader drive axle differential lock. The angle sensor 6 detects the steering angle and outputs it to the control unit 5 to compare the received angle with the straight-ahead angle range setting value to determine the loader's walking or steering situation; Case 1: If it is within the setting value range, it is determined to be a straight-ahead state; Case 2: If the received angle is less than the value within the straight-ahead angle range setting value, it is determined to be a left-turning state; Case 3: If the received angle is greater than the value within the straight-ahead angle range setting value, it is determined to be a right-turning state. The front-drive left wheel speed sensor 41 and the speed sensor 42 respectively detect the speed of the left and right tires of the front drive axle, and output them to the control unit 5 for calculating the speed difference between the left and right tires.

[0040] The control unit 5 determines whether to turn on the differential lock function according to the detection status in the following situations:

[0041] Scenario 1: The loader is in a straight-ahead state, the absolute value of the speed difference between the left and right tires is less than or equal to the set value of the speed difference between the left and right tires in the straight-ahead state, and the differential lock function is not enabled.

[0042] Scenario 2: The loader is in a straight-ahead state, the absolute value of the speed difference between the left and right tires is greater than the set value of the speed difference between the left and right tires in the straight-ahead state, and the differential lock function is turned on.

[0043] Scenario 3: The loader is in the left-turning state, the rotation speed of the left tire is greater than that of the right tire, and the differential lock function is turned on.

[0044] Scenario 4: The loader is in the left-turn state, the difference between the rotation speed of the right tire and the rotation speed of the left tire is less than or equal to the setting value of the left and right tire rotation speed difference in the turning state, and the differential lock function is not turned on.

[0045] Scenario 5: The loader is in the left-turn state, the difference between the right tire speed and the left tire speed is greater than the left and right tire speed difference setting value in the turning state, and the differential lock function is turned on.

[0046] Situation 6: The loader is in right-turning state, the speed of the right tire is greater than that of the left tire, and the differential lock function is turned on.

[0047] Situation 7: The loader is in the right-turn state, the difference between the left tire speed and the right tire speed is less than or equal to the left and right tire speed difference setting value in the turning state, and the differential lock function is not turned on.

[0048] Situation 8: The loader is in the right-turn state, the difference between the left tire speed and the right tire speed is greater than the left and right tire speed difference setting value in the turning state, and the differential lock function is turned on.

[0049] After the differential lock function is turned on, the angle sensor 6, the front-drive left wheel speed sensor 41, and the front-drive rear wheel speed sensor 42 detect the angle and speed in real time, and transmit them to the control unit 5 for condition judgment. When the differential lock closing condition is met, the differential lock function is automatically closed.

[0050] The specific parameters of this embodiment and the program edited according to the above method adopt existing methods well known to those skilled in the art and will not be described in detail here.

[0051] Embodiment 2:

[0052] The difference between this embodiment and the first embodiment is that the control mode of the loader drive axle in this embodiment is only the front drive axle drive mode, and the specific drive mode is the same as that in the first embodiment.

[0053] Embodiment three:

[0054] The difference between this embodiment and the first embodiment is that the control mode of the loader drive axle in this embodiment is only the rear drive axle drive mode, and the specific drive mode is the same as that in the first embodiment.

[0055] The above contents are only preferred embodiments of the present invention and are not intended to limit the present invention in any form. Any simple modifications and equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A loader drive axle differential lock control method, characterized in that: Specifically include: (1) A differential lock switch is provided on the drive axle of the loader, and the differential lock switch is connected to a control unit (5). The differential lock is turned on and off by the control unit (5). The differential lock manual mode is turned on by the differential lock switch. After being turned on, the differential lock is kept on for a set holding time. After the time is over, the differential lock automatic mode is entered. The control unit (5) determines the opening and closing of the differential lock according to a judgment condition. Within the holding time set in the differential lock manual mode, if the differential lock switch is pressed again, the manual mode is exited and the differential lock automatic mode is directly entered; (2) When the differential lock automatic mode is entered, the vehicle's driving state is detected by the vehicle's angle sensor, and the vehicle's driving state is determined as "straight ahead", "left turn" or "right turn"; (3) A preset value of the speed difference between the left and right tires of the driving axle in the straight-ahead state is set. In the "straight-ahead state" of the differential lock automatic mode, the speed of the left tire of the driving axle is detected by the left wheel speed sensor on the same driving axle, and the speed of the right tire of the driving axle is detected by the right wheel speed sensor. When the absolute value of the speed difference between the left and right tires is less than or equal to the set value of the speed difference between the left and right tires in the straight-ahead state, the differential lock is closed; when the absolute value of the speed difference between the left and right tires is greater than the set value of the speed difference between the left and right tires in the straight-ahead state, the differential lock is opened; (4) A preset left-turn state left- and right-tire speed difference setting value of the drive axle is set. In the "left-turn state" of the differential lock automatic mode, the left wheel speed sensor on the same drive axle detects the speed of the left tire of the drive axle, and the right wheel speed sensor detects the speed of the right tire of the drive axle. When the speed of the left tire is greater than the speed of the right tire, the differential lock is turned on; when the difference between the speed of the right tire and the speed of the left tire is less than or equal to the left-turn state left- and right-tire speed difference setting value, the differential lock is turned off; when the difference between the speed of the right tire and the speed of the left tire is greater than the left-turn state left- and right-tire speed difference setting value, the differential lock function is turned on; (5) A preset value for the speed difference between the left and right tires in the right-steering state of the drive axle is set. In the "right-steering state" of the differential lock automatic mode, the speed of the left tire of the drive axle is detected by the left wheel speed sensor on the same drive axle, and the speed of the right tire of the drive axle is detected by the right wheel speed sensor. When the speed of the right tire is greater than the speed of the left tire, the differential lock is turned on; when the difference between the speed of the left tire and the speed of the right tire is less than or equal to the setting value for the speed difference between the left and right tires in the right-steering state, the differential lock is turned off; when the difference between the speed of the left tire and the speed of the right tire is greater than the setting value for the speed difference between the left and right tires in the right-steering state, the differential lock is turned on.

2. A loader drive axle differential lock control method according to claim 1, characterized in that: The drive axle with the differential lock function is a front-wheel drive axle, a rear-wheel drive axle, or a front- and rear-wheel drive axle.

3. A loader drive axle differential lock control method according to claim 2, characterized in that: When the drive axle is a front-wheel drive axle or a rear-wheel drive axle, the differential locks of the front-wheel drive axle and the rear-wheel drive axle are both provided with differential lock switches and are independently controlled.

4. A loader drive axle differential lock control method according to any one of claim 1, characterized in that: The control unit (5) controls the on and off of the differential lock hydraulic oil by controlling the proportional solenoid valve.

5. The method for controlling a differential lock of a loader drive axle according to claim 1, characterized in that: The control unit (5) is connected to a display and parameter setting device for displaying the actual state of the differential lock output by the control unit (5) and capable of adjusting parameter values.

6. A loader drive axle differential lock control method according to claim 1, characterized in that: The loader is provided with rotation speed sensors on the front two wheels, the rear two wheels or the front and rear four wheels.

7. A loader drive axle differential lock control method according to claim 1, characterized in that: The differential lock is connected to a pressure sensor, and a pressure value of the drive axle differential lock system is preset. The pressure sensor is connected to a control unit (5) to detect the differential lock system pressure in real time. The control unit (5) determines the opening and closing state of the differential lock through the signal collected by the pressure sensor. If the differential lock system pressure is greater than the differential lock set pressure value, the differential lock is in the closed state.

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