Hydrostatic loader walking system protection control method and walking system

Abstract

A kind of static hydraulic loader walking system protection control method and walking system, comprising: classifying system failure, when monitoring static hydraulic loader walking system failure, actual system failure is compared and analyzed;When actual system failure is a kind of failure, switch transmission route, obtain current vehicle load information, and according to the target torque required by current vehicle load, the output torque of current transmission route is compared and adjusted, when the condition of changing power transmission route is met, and no damage and irreversible failure is generated to system, by changing transmission route, the power of system is reduced and the speed of system is limited to make equipment not immediately stop, ensure that output torque meets the current load demand, greatly improve the efficiency of equipment, reduce the downtime risk caused by system failure, and ensure work efficiency;When actual system failure is a kind of failure, directly stop.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery technology, and in particular to a protection and control method for the walking system of a hydrostatic loader and the walking system itself. Background Technology

[0002] The walking system of a hydrostatic loader is a system in which the engine drives a hydraulic pump, which in turn drives two hydraulic motors to achieve walking. The two hydraulic motors are a clutch motor and a speed motor. The clutch motor is equipped with an electronically controlled clutch. The vehicle speed gradually increases with the travel of the accelerator pedal. During the initial stage, the two hydraulic motors are synchronized to achieve low-speed, high-torque power output. When the vehicle speed exceeds a certain value, the controller controls the clutch to disconnect the power from the clutch motor, and only the speed motor works to achieve high-speed forward movement of the vehicle.

[0003] Due to the complexity of the walking system control, malfunctions are inevitable during operation. In order to protect the walking system and ensure system fault diagnosis, a fault protection control method for electric construction machinery has emerged (such as publication number CN115324148A). This method classifies faults, reduces the power of the motor and hydraulic pump, and controls the motor to adjust the gear or controls the hydraulic pump to correct the pump torque based on the difference between the target speed corresponding to the current gear after the current motor power reduction and the current motor speed, so as to continue to provide sufficient power to maintain the operation of the electric construction machinery.

[0004] However, existing fault protection and control methods can only solve faults around the power line and cannot detect faults in components on the transmission line. For example, if the motor or hydraulic pump fails, it may continue to work. Furthermore, there is no control associated with the current load. Even if the power is reduced, it may still be unable to meet the current load conditions and thus fail to operate. This not only affects work efficiency but also easily causes damage to other components of the walking system. Summary of the Invention

[0005] To address the technical problems of existing fault protection and control methods in the background art, which are unable to detect faults in components along the transmission route and lack control associated with the current load, even with reduced power, the current load conditions may still not be met, thus preventing operation, this invention provides a protection and control method for the walking system of a hydrostatic loader and a walking system.

[0006] The technical solution of this invention is as follows:

[0007] This invention provides a protection and control method for the walking system of a hydrostatic loader, comprising:

[0008] The system faults are classified, and when a fault is detected in the walking system of the hydrostatic loader, a comparative analysis of the actual system faults is conducted.

[0009] When the actual system fault is classified as a Class I fault, the transmission route of the walking system is switched, the current vehicle load information is obtained, and the output torque of the current transmission route is compared and adjusted according to the target torque required by the current vehicle load. By classifying and analyzing the faults of the walking system, when the conditions for changing the power transmission route are met and the system is not damaged or irreversibly damaged, the system power is reduced and the vehicle speed is limited by changing the transmission route to prevent the equipment from stopping immediately. This method greatly improves the efficiency of the equipment, reduces the downtime risk caused by system faults, and ensures work efficiency through emergency settings and protection restrictions on the walking system.

[0010] When the actual system fault is a Class II fault, the system should be shut down immediately.

[0011] Preferably, the transmission route includes a first transmission route and a second transmission route. The first transmission route includes a first motor and a clutch, and the second transmission route includes a second motor. Type I faults include first motor faults, second motor faults, and clutch faults, while Type II faults include pump faults. By dividing the transmission route, the transmission route can be switched according to the actual fault, thus ensuring work efficiency.

[0012] Preferably, if the torque output by the current transmission route is greater than the target torque required under the current load and exceeds a preset comparison threshold, the output torque is adjusted to be equal to the target torque required under the current load; if it does not exceed the preset comparison threshold, the displacement of the existing hydraulic pump and / or the first motor / second motor is maintained according to the current vehicle speed.

[0013] Preferably, if the torque output by the current transmission route is less than the target torque required under the current load and exceeds a preset comparison threshold, the output torque is adjusted to the target torque required under the current load; if the preset comparison threshold is not exceeded, only the displacement of the first motor / second motor is adjusted to the target torque corresponding to the current load.

[0014] Preferably, if adjusting the displacement of the hydraulic pump and / or the first motor / second motor to the target torque required under the current load still fails to meet the actual torque required for the current load, then the displacement of the first motor / second motor is adjusted to the maximum, the displacement of the hydraulic pump is limited to the maximum displacement of the current system, and the system speed is reduced. The output torque of the transmission route is compared with the target torque required for the current vehicle load and adjusted so that the transmission system can meet the walking requirements as much as possible, ensuring vehicle movement and guaranteeing work efficiency.

[0015] Preferably, if the current vehicle speed cannot be effectively monitored, the current vehicle speed is replaced by the theoretical vehicle speed, which improves emergency response capabilities and avoids the impact of damage to the detection components on monitoring and vehicle speed adjustment.

[0016] Preferably, the current vehicle load information is divided into light load, medium load, and heavy load. The load weight is less than or equal to 60% of the bucket's rated load weight, which is considered light load; the load weight is greater than 60% of the bucket's rated load weight but less than or equal to 85%, which is considered medium load; and the load weight is greater than 85% of the bucket's rated load weight, which is considered heavy load.

[0017] The present invention provides a walking system, comprising: a controller, wherein the input interface of the controller is connected to a switching mechanism, a pump pressure sensor of a hydraulic pump, and speed sensors on a first motor and a second motor; the output interface of the controller is electrically connected to a proportional solenoid valve on a hydraulic pump, a first motor, a second motor, and a clutch; and the CAN bus communication interface of the controller is connected to a smart instrument and a bus communication port of an engine ECU.

[0018] Preferably, it also includes a detection mechanism, which includes a pressure sensor located at the working valve and a vehicle speed sensor located at the transmission component.

[0019] As can be seen from the above technical solutions, the advantages of the present invention are:

[0020] By classifying and analyzing the failures of the walking system, when the conditions for changing the power transmission route are met without causing damage or irreversible failures to the system, the system power is reduced and the vehicle speed is limited by changing the transmission route to prevent the equipment from stopping immediately and to ensure that the output torque meets the current load requirements. This method greatly improves the efficiency of the equipment, reduces the downtime risk caused by system failures, and ensures work efficiency through emergency settings and protection restrictions on the walking system. Attached Figure Description

[0021] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the walking system according to one or more embodiments of the present invention;

[0023] Figure 2 This is a schematic diagram of the control flow according to one or more embodiments of the present invention;

[0024] The components represented by the various reference numerals in the diagram are:

[0025] 1. Controller; 2. Pump proportional solenoid valve; 3. First motor proportional solenoid valve; 4. Second motor proportional solenoid valve; 5. Clutch proportional solenoid valve; 6. Pump pressure sensor; 7. First motor speed sensor; 8. Second motor speed sensor; 9. Intelligent instrument; 10. ECU; 11. Switching mechanism. Detailed Implementation

[0026] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the specific embodiments. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this patent, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this patent.

[0027] Example 1

[0028] Because hydrostatic loaders use an engine to drive a hydraulic pump, which in turn drives the front and rear axles via a hydraulic motor and gearbox, hydrostatic transmission eliminates the concept of gears, achieving stepless speed change. The engine speed and machine speed can change smoothly and continuously, allowing the engine to operate within a more efficient range and maximize efficiency. At the same time, the expansion of intelligent control functions under various working conditions becomes possible.

[0029] In a typical embodiment of the present invention, such as Figure 2 As shown, a protection and control method for the walking system of a hydrostatic loader is proposed. When a fault occurs in the walking system, the fault is classified and analyzed. If the fault can be corrected by changing the power transmission method, the transmission route of the walking system is changed. The load information of the current vehicle is acquired in real time, and the target torque required under the current load is compared with the current torque. This is used to control the hydraulic pump and / or motor proportional current correction method to achieve adaptive protection of the whole machine, ensuring that the equipment can walk normally. The method specifically includes:

[0030] The system faults are classified, and when a fault is detected in the walking system of the hydrostatic loader, a comparative analysis of the actual system faults is conducted.

[0031] When the actual system fault is a Class I fault, the transmission route of the walking system is switched to perform adaptive protection for the whole machine.

[0032] When the actual system fault is classified as a Class II fault, the system should be shut down immediately to protect the hydraulic components of the transmission system and prevent damage.

[0033] Among them, the faulty components of the first type of fault include the first motor (i.e., clutch motor) fault, the second motor (i.e. speed motor) fault, and clutch fault, while the faulty component of the second type of fault is the pump fault (i.e. hydraulic pump fault).

[0034] The transmission route includes a first transmission route and a second transmission route. The first transmission route includes a first motor and a clutch, and the second transmission route includes a second motor. In one type of fault, it is divided into component faults of the first transmission route or component faults of the second transmission route, that is, it is divided into one or both of the first motor and the clutch or a fault of the second motor.

[0035] When the system fault is a Class I fault, adaptive protection can be achieved by switching the transmission route without affecting work efficiency; when the system fault is a Class II fault, the machine should be stopped directly to avoid damage to hydraulic components.

[0036] When the system fault is classified as a Class I fault, after switching the transmission route, the torque needs to be adjusted according to the current load to ensure that the output torque meets the current load requirements as much as possible and to ensure working efficiency. That is, the current vehicle load information is obtained, the target torque required under the current vehicle load is calculated, and it is compared with the torque provided by the current transmission route after switching. The torque is adjusted according to the comparison result.

[0037] Specifically, if the torque provided by the current transmission route is greater than the target torque required under the current load and exceeds a preset comparison threshold, the hydraulic pump and / or the first motor / second motor are controlled to perform proportional current correction so that the current torque is equal to the target torque required under the current load; if the torque provided by the current transmission route is greater than the target torque required under the current load and does not exceed the preset comparison threshold, the existing displacement of the hydraulic pump and / or the first motor / second motor is maintained according to the current vehicle speed.

[0038] If the torque provided by the current transmission route is less than the target torque required under the current load and exceeds the preset comparison threshold, then the hydraulic pump and / or the first motor / second motor are controlled to perform proportional current correction, adjusting the displacement of the hydraulic pump and / or the first motor / second motor to the target torque required under the current load; if the torque provided by the current transmission route is less than the target torque required under the current load and does not exceed the preset comparison threshold, then only the displacement of the first motor / second motor is adjusted to the target torque corresponding to the current load.

[0039] If adjusting the displacement of the hydraulic pump and / or the first motor / second motor to the target torque required under the current load still fails to meet the actual torque required for the current load, then the displacement of the first motor / second motor is adjusted to the maximum, the displacement of the hydraulic pump is limited to the maximum displacement of the current system, and the system speed is reduced.

[0040] The current vehicle load information is divided into light load, medium load and heavy load. The thresholds and intervals for light load, medium load and heavy load can be manually set and calibrated according to the target work object and working conditions and stored in the controller 1. The means of obtaining the current vehicle load information is a detection device installed on the current vehicle, working device or walking device. This detection device is composed of various detection sensors (such as pressure sensors).

[0041] In this embodiment, light load, medium load, and heavy load are defined based on the loader's rated load capacity during current operation:

[0042] A load capacity of less than or equal to 60% of the bucket's rated load capacity is considered a light load.

[0043] The load capacity is defined as 60% to 85% of the rated load capacity of the bucket, which is considered a medium load.

[0044] A load capacity exceeding 85% of the bucket's rated load capacity is considered a heavy load.

[0045] It is understandable that the preset comparison threshold is set according to the actual situation and stored in the controller 1. The displacement of the hydraulic pump and / or the first motor / second motor and the current correspond to a linear relationship, which is stored in the controller 1.

[0046] It is important to note that the current vehicle load information collected is the load pressure signal under stable conditions to prevent load fluctuations from affecting the accuracy of the comparison.

[0047] In this embodiment, when the second transmission route fails, the load comparison and torque adjustment process are illustrated using one of the following working conditions: light load, medium load, and heavy load:

[0048] The vehicle is currently switching to the first transmission route of hydraulic pump-clutch-first motor for power transmission;

[0049] If the detected current vehicle load is within the light load range, the torque provided by the current first transmission route is compared with that required under light load conditions. If the torque provided by the current first transmission route is greater than the target torque required under light load conditions and exceeds the preset comparison threshold, then the current torque of the vehicle meets the torque requirements under light load conditions. Based on the current vehicle speed, the displacement of the hydraulic pump and the first motor is adjusted so that the current torque is equal to the target torque required under light load conditions, so that the equipment can still maintain normal operation.

[0050] Similarly, if the currently detected load is within the range of medium load conditions, the controller calculates the torque provided by the current first transmission route under the current medium load and compares it with the torque required under the medium load conditions. If the torque provided by the current first transmission route is less than the target torque required under the medium load conditions and does not exceed the preset comparison threshold, the displacement of the first motor is adjusted and limited. This adjusts the output torque of the first motor to meet the target torque corresponding to the current medium load. At the same time, the vehicle speed can be increased or decreased according to the driver's driving intention.

[0051] Similarly, if the currently detected load is within the heavy-load operating range, the displacement of the pump and / or motor is adjusted to the target torque required under the current load. If the adjustment still cannot meet the torque required under the current load, the displacement of the first motor is adjusted to the maximum, so that the whole vehicle enters constant torque control, and the displacement of the hydraulic pump is limited to the maximum displacement of the current system, so that the whole vehicle meets the torque requirement of the current heavy-load operating condition, and the system speed is reduced. This ensures that the equipment does not stop directly after the system malfunctions, and the torque required under the current vehicle load can be met by changing the transmission route through torque adjustment and speed change, so that the equipment can walk and move normally.

[0052] In practical applications, the system can also be configured with three types of faults: sensor and solenoid valve faults that do not affect vehicle movement and operation, and which do not cause damage or irreversibility to the system. These three types of faults only trigger an alarm and do not require switching of the transmission line or shutdown. For example, if a minor fault occurs in the transmission line (such as a damaged solenoid valve) but the vehicle speed requirement is met and the light load operation needs are met, and there is no need to immediately stop the machine and prevent the vehicle from moving, then switching of the transmission line is not required. The fault information of the transmission line can be sent to the intelligent instrument 9 through the controller to indicate the location of the fault to the driver and remind the driver to reduce the load in the next work cycle.

[0053] Similarly, when a fault occurs in the first transmission line during normal driving, such as a short circuit in the clutch proportional solenoid valve 5 connected to the first motor, preventing engagement and disengagement with the first motor, the fault can be classified and analyzed. To ensure the vehicle does not lose power, the controller can switch to the second transmission line, relying on the second motor for movement. At this time, the vehicle's speed and torque cannot reach their maximum. The controller 1 collects the current load information and compares it with the stored load and torque information, outputting a limit on the system's speed and torque. Simultaneously, the controller outputs a proportional current to control the hydraulic pump and the solenoid valves of the second motor. Based on the comparison between the current vehicle load information and the torque information required by the system, corresponding measures such as reducing system power and limiting vehicle speed are taken to ensure normal system operation. At the same time, the fault information is sent to the intelligent instrument through the controller, allowing the operator to clearly understand the current fault of the vehicle and reminding the operator that the power and speed are currently limited, requiring a reduction in load in the next work cycle.

[0054] Additionally, if the speed sensors of the first and second motors fail and cannot effectively monitor the current speed values, in order to ensure that the vehicle does not lose power and the system stops, the controller 1 can replace the current vehicle speed calculation with the theoretical vehicle speed value. The theoretical vehicle speed is obtained by the linear relationship between the current pump current and motor current and the displacement. Then, through the fixed transmission ratio of the gearbox and axle, the theoretical vehicle speed under the current state can be calculated. All of the above theoretical values ​​are stored in the controller's EEPROM. At the same time, if one or both speed sensors of the first and second motors fail, the fault information will be sent to the smart instrument through the controller, so that the operator is aware of the current fault of the vehicle and is reminded that the current situation is due to sensor failure and vehicle speed replacement, and that the operator needs to reduce the operating load and perform timely maintenance.

[0055] In summary, by classifying and analyzing the faults of the walking system, and through the comprehensive evaluation and calculation of controller 1, when the conditions for changing the power transmission route are met without causing damage or irreversible faults to the system, the equipment can be prevented from stopping immediately by changing the transmission route, reducing the system power, and limiting the system speed, in accordance with the characteristics of the hydrostatic loader system. This method, through emergency settings and protective restrictions on the walking system, greatly improves the efficiency of the equipment, reduces the downtime risk caused by system faults, and ensures work efficiency.

[0056] It is understood that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The implemented program can be stored in a computer-readable storage medium. When executed, the program can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk drive (HDD), or solid-state drive (SSD), etc.; the storage medium can also include combinations of the above types of memory.

[0057] In this embodiment, the switching of the transmission route is different from the shifting of the gearbox. It only involves disengaging one motor to perform adaptive protection of the whole machine, and switching to another motor to enable the whole machine to move normally.

[0058] Example 2

[0059] In a typical embodiment of the present invention, such as Figure 1 As shown, a walking system for a hydrostatic loader is proposed, comprising: a controller 1, a hydraulic pump, a first motor, a second motor, a clutch, and a switching mechanism 11.

[0060] The input interface of controller 1 is electrically connected to the switching mechanism 11, the pump pressure sensor 6 of the hydraulic pump, and the speed sensors on the first and second motors. It is used to collect feedback data of the output signals of the hydraulic pump and the first and second motors in real time, and generate control commands to be output to the hydraulic pump or the first / second motor based on the feedback data of each sensor. At the same time, it can determine whether the hydraulic pump or the first / second motor is working normally. The output interface of controller 1 is electrically connected to the proportional solenoid valve on the hydraulic pump, the first motor, the second motor, and the clutch. It is used to send the generated control commands of the hydraulic pump or the first / second motor to the hydraulic pump and the first / second motor, and adjust the control current in real time according to the control commands.

[0061] Specifically, such as Figure 1 As shown, the input interface of controller 1 is connected to switching mechanism 11, pump pressure sensor 6, first motor speed sensor 7 and second motor speed sensor 8, and the output interface is connected to pump proportional solenoid valve 2, first motor proportional solenoid valve 3, second motor proportional solenoid valve 4 and clutch proportional solenoid valve 5.

[0062] The CAN bus communication interface of controller 1 is connected to the bus communication ports of intelligent instrument 9 and engine ECU 10. Controller 1 collects the current transmission route information input by the switching mechanism 11 and transmits it to intelligent instrument 9 via CAN bus. When the transmission route is switched due to a fault, alarm information, downshift information, etc. can be displayed in intelligent instrument. Furthermore, the current engine speed information can be transmitted to controller 1 via engine ECU 10. When the system malfunctions and it is necessary to reduce the engine output speed and / or torque, controller 1 can transmit control commands to engine ECU 10 via CAN bus.

[0063] It also includes a detection mechanism, which includes a pressure sensor and a vehicle speed sensor. The pressure sensor is located at the system's travel valve to detect the load pressure signal and generate the current vehicle load information; the vehicle speed sensor is located at the transmission components to detect the vehicle's current travel speed.

[0064] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A protection and control method for the walking system of a hydrostatic loader, characterized in that, include: The system faults are classified, and when a fault is detected in the walking system of the hydrostatic loader, a comparative analysis of the actual system faults is conducted. When the actual system fault is a Class I fault, the transmission route of the walking system is switched, the current vehicle load information is obtained, and the output torque of the current transmission route is compared and adjusted according to the target torque required by the current vehicle load. When the actual system fault is a Class II fault, the system is shut down immediately. The transmission route includes a first transmission route and a second transmission route. The first transmission route includes a first motor and a clutch, and the second transmission route includes a second motor. Type I faults include first motor faults, second motor faults, and clutch faults. Type II faults include pump faults. When the torque output by the current transmission route is greater than the target torque required under the current load and exceeds the preset comparison threshold, the output torque is adjusted to be equal to the target torque required under the current load. If the preset comparison threshold is not exceeded, the displacement of the existing hydraulic pump and / or the first motor / second motor will be maintained according to the current vehicle speed. If the torque output of the current transmission route is less than the target torque required under the current load and exceeds the preset comparison threshold, the output torque will be adjusted to the target torque required under the current load. If the preset comparison threshold is not exceeded, the displacement of the first motor / second motor is adjusted to the target torque corresponding to the current load. If adjusting the displacement of the hydraulic pump and / or the first motor / second motor to the target torque required under the current load still cannot meet the actual torque required for the current load, the displacement of the first motor / second motor is adjusted to the maximum, the displacement of the hydraulic pump is limited to the maximum displacement of the current system, and the system speed is reduced.

2. The method for protecting and controlling the walking system of a hydrostatic loader according to claim 1, characterized in that: If the current vehicle speed cannot be effectively monitored, the theoretical vehicle speed will be used instead.

3. The method for protecting and controlling the walking system of a hydrostatic loader according to claim 1, characterized in that: The current vehicle load information is divided into light load, medium load, and heavy load. The load weight is less than or equal to 60% of the bucket's rated load weight, which is considered light load; the load weight is greater than 60% of the bucket's rated load weight but less than or equal to 85%, which is considered medium load; and the load weight is greater than 85% of the bucket's rated load weight, which is considered heavy load.

4. A walking system, characterized in that, include: The controller (1) is used to perform the protection control method of the hydrostatic loader walking system as described in any one of claims 1-3. The input interface of the controller (1) is connected to the switching mechanism (11), the pump pressure sensor (6) of the hydraulic pump, and the speed sensors on the first motor and the second motor. The output interface of the controller (1) is electrically connected to the proportional solenoid valves on the hydraulic pump, the first motor, the second motor, and the clutch. The CAN bus communication interface of the controller (1) is connected to the bus communication port of the smart instrument (9) and the engine ECU (10).

5. A walking system according to claim 4, characterized in that, It also includes a detection mechanism, which includes a pressure sensor located at the working valve and a vehicle speed sensor located at the transmission component.

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