Control method and control system for electronic fan of loading machine and medium

Abstract

The embodiment of the invention relates to a control method and system for an electronic fan of a loader and a medium, and belongs to the technical field of loaders, the control method comprises the steps that under the condition that the opening degree of an accelerator is larger than a first threshold value, and the load rate of a hydraulic motor is larger than a second threshold value or the load rate of a walking motor is larger than a third threshold value, it is determined that a first working condition is met; based on the current engine outlet water temperature, whether the current engine outlet water temperature is larger than a first low-limit threshold value for starting the electronic fan or not is determined; under the condition that the first working condition is met and the current engine outlet water temperature is larger than a first low-limit threshold value for starting the electronic fan, control over the electronic fan is unlocked; under the condition that the control of the electronic fan is unlocked, the changed rotating speed of the electronic fan is determined according to the current outlet water temperature and the preset relation curve of the outlet water temperature and the rotating speed; the rotating speed of the electronic fan can be prevented from being suddenly increased and continuously accelerated, and obvious noise feeling can be avoided.

Description

Technical Field

[0001] The present application relates to the technical field of loader cooling fans, and more specifically, to a control method, control system and medium for a loader electronic fan. Background Art

[0002] The existing control logic of the loader's electronic fan is based on temperature, and only responds to the corresponding fan speed. However, the control logic does not take into account the user experience. In some special cases of the loader, such as the no-load reverse working condition of the V-type operation, the whole vehicle runs smoothly, but the engine running condition and the engine water temperature do not change at the same time in the instantaneous changing working condition. The engine water temperature and hydraulic oil temperature have lags. If the speed of the electronic fan jumps or continuously accelerates in a stable state, the driver will feel obvious noise.

[0003] The sudden increase in fan speed under light load and stable state is also inconsistent with the driver's perception. The fan of traditional fuel vehicles is directly connected to the engine, and the fan speed will inevitably increase as the engine speed increases. Now that the electronic fan is decoupled from the throttle, coupled with the continuity and lag of the temperature increase, the sound pattern is no longer the same as that of a fuel vehicle, which may cause misunderstandings among drivers. Summary of the invention

[0004] The present application is provided to solve the above defects existing in the prior art. A control method, control system and medium for a loader electronic fan are needed, which can avoid sudden increase and continuous acceleration of the electronic fan speed and obvious noise perception based on the existing electronic fan control logic.

[0005] In a first aspect of the present application, a control method for an electronic fan of a loader is provided, the control method comprising: obtaining a throttle opening, a hydraulic motor load rate and a travel motor load rate of an engine of the loader; determining that a first operating condition is satisfied when the throttle opening is greater than a first threshold value, and the hydraulic motor load rate is greater than a second threshold value or the travel motor load rate is greater than a third threshold value; determining, based on a current engine water outlet temperature, whether the current engine water outlet temperature is greater than a first lower threshold value for starting the electronic fan; unlocking control of the electronic fan when the first operating condition is satisfied and the current engine water outlet temperature is greater than the first lower threshold value for starting the electronic fan; when the control of the electronic fan is unlocked, determining a changed speed of the electronic fan according to the current water outlet temperature and a preset relationship between the water outlet temperature and the speed; and determining a PWM duty cycle based on the changed speed.

[0006] According to a second aspect of the present application, a control system for an electronic fan of a loader is provided, the control system comprising a processor, the processor being configured to: obtain a throttle opening, a hydraulic motor load rate and a travel motor load rate of the engine of the loader; determine that a first operating condition is satisfied when the throttle opening is greater than a first threshold value, and the hydraulic motor load rate is greater than a second threshold value or the travel motor load rate is greater than a third threshold value; determine, based on a current engine water outlet temperature, whether the current engine water outlet temperature is greater than a first lower threshold value for starting the electronic fan; unlock control of the electronic fan when the first operating condition is satisfied and the current engine water outlet temperature is greater than the first lower threshold value for starting the electronic fan; when the control of the electronic fan is unlocked, determine a changed speed of the electronic fan according to the current water outlet temperature and a preset relationship between the water outlet temperature and the speed; and determine a PWM duty cycle based on the changed speed.

[0007] According to a third aspect of the present application, a non-transitory computer-readable medium is provided, on which instructions are stored. When executed by a processor, the instructions execute the steps of the method for controlling the electronic fan of a loader as described in any embodiment of the present application.

[0008] The control method, control system and medium of the loader electronic fan provided in each embodiment of the present application use the engine throttle opening, hydraulic motor load rate and travel motor load rate of the vehicle status to identify whether the vehicle is in a stable working condition. If the stable working condition is met, the control of the electronic fan is not unlocked, allowing the electronic fan to continue to run in the original control mode. If it is in a non-stable working condition, the control of the electronic fan is unlocked, and the speed and PWM duty cycle are determined according to a preset relationship curve so as to change the speed of the electronic fan in real time, avoid sudden acceleration or continuous acceleration of the electronic fan, and avoid obvious noise perception. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In the drawings, which are not necessarily drawn to scale, the same reference numerals may describe similar parts in different views. The same reference numerals with letter suffixes or different letter suffixes may represent different instances of similar parts. The accompanying drawings generally illustrate various embodiments by way of example and not limitation, and together with the specification and claims, are used to illustrate the embodiments applied for. When appropriate, the same reference numerals are used throughout the drawings to refer to the same or similar parts. Such embodiments are illustrative and are not intended to be exhaustive or exclusive embodiments of the present apparatus or method.

[0010] Figure 1 A flow chart showing a method for controlling an electronic fan of a loader according to a first embodiment of the present application; Figure 2A flow chart showing a method for controlling an electronic fan of a loader according to a second embodiment of the present application; Figure 3 A structural schematic diagram of a control system for an electronic fan of a loader according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0011] In order to enable those skilled in the art to better understand the technical solution of the present application, the present application is described in detail below in conjunction with the accompanying drawings and specific implementation examples. The embodiments of the present application are further described in detail below in conjunction with the accompanying drawings and specific implementation examples, but are not intended to limit the present application.

[0012] The words "first", "second" and similar words used in this application do not indicate any order, quantity or importance, but are only used to distinguish. The words "include" or "comprise" and similar words mean that the elements before the word include the elements listed after the word, and do not exclude the possibility of including other elements.

[0013] According to an embodiment of the present application, a method for controlling an electronic fan of a loader is provided. Figure 1 As shown, the control method includes the following steps. In step 101, the throttle opening of the engine, the load rate of the hydraulic motor and the load rate of the travel motor of the loader are obtained. In this way, it is possible to obtain whether the throttle opening of the engine is large and whether the load of the motor is large, so as to obtain an accurate stable operating condition of the loader. It can deal with the problem of lagging engine water temperature and hydraulic oil temperature when the operating condition changes, and obtain the vehicle operating condition in a timely and accurate manner.

[0014] In step 102, when the throttle opening is greater than the first threshold, and the hydraulic motor load rate is greater than the second threshold or the travel motor load rate is greater than the third threshold, it is determined that the first working condition is met. The load rate of either the hydraulic motor or the travel motor is large, combined with the throttle opening, can accurately determine the stable operation state of the loader.

[0015] In step 103, based on the current engine outlet water temperature, it is determined whether the current engine outlet water temperature is greater than the first lower threshold for starting the electronic fan. If the engine outlet water temperature is greater than the first lower threshold, it means that the electronic fan meets the starting condition.

[0016] In step 104, when the first working condition is met and the current engine outlet water temperature is greater than the first lower threshold for starting the electronic fan, the control of the electronic fan is unlocked. The existing electronic fan control is related to the engine outlet water temperature. If the control of the electronic fan is not unlocked, the speed of the electronic fan can only be changed when a change in the outlet water temperature is detected. Therefore, unlocking the control of the electronic fan can facilitate the change of the speed of the electronic fan and avoid a sudden increase in the speed of the electronic fan.

[0017] In step 105, when the control of the electronic fan is unlocked, the changed speed of the electronic fan is determined according to the current outlet water temperature and the preset relationship between the outlet water temperature and the speed; and the PWM duty cycle is determined based on the changed speed. Based on the preset relationship between the outlet water temperature and the speed, the changed speed corresponding to the current outlet water temperature can be obtained by looking up a table. In this way, the speed of the electronic fan can be changed based on the working conditions, rather than simply relying on the engine outlet water temperature, so that the speed of the electronic fan is changed with a smaller gradient, avoiding instantaneous large changes in the speed of the electronic fan, and better heat dissipation of the engine.

[0018] This application is aimed at electric loaders or hybrid loaders. Traditional loaders are oil-driven loaders. Oil-driven loaders are engine-driven fans. The higher the engine speed, the higher the fan speed. The fan speed has nothing to do with the water temperature. Electric loaders or hybrid loaders are equipped with electronic fans, which are related to the water outlet temperature of the engine. Taking reversing as an example, when the loader involved in this application starts to reverse, the water temperature has not risen yet. During the reversing process, the water temperature begins to rise. Therefore, during the delayed reaction process of the sudden increase in water temperature, the speed of the electronic fan may suddenly increase.

[0019] By checking that the hydraulic motor load rate is greater than the second threshold or the travel motor load rate is greater than the third threshold, combined with the throttle opening, it can be determined whether it is a high load situation. If it is a high load situation, the electronic fan control is unlocked and the speed of the electronic fan is adjusted according to the actual engine water outlet temperature to avoid a sudden increase in the speed of the electronic fan and the resulting noise.

[0020] The first lower threshold, the first threshold, the second threshold and the third threshold can be set according to the actual operation of the loader.

[0021] like Figure 2 As shown, in some embodiments, when the rate of change of the throttle opening is greater than the fourth threshold value within the first time interval, it is determined that the second operating condition 201 is met; when the second operating condition 201 is met and condition 202 is met, that is, the current engine outlet water temperature is greater than the first lower threshold value for starting the electronic fan, step 204 is executed to unlock the control of the electronic fan. If the rate of change of the throttle opening is large, it means that the operating condition of the loader has changed greatly within a period of time. At this time, when the load is light, the throttle is pressed faster, so the engine noise is large, then the control of the electronic fan is unlocked to avoid a sudden increase in the fan speed during the change of the operating condition.

[0022] In some embodiments, the throttle opening at the initial moment and the throttle opening at the end moment corresponding to the first time interval are obtained, and the throttle opening change rate of the first time interval is calculated. The processor can obtain the throttle opening at each moment, and calculate the throttle opening change rate when the first time interval is reached, so as to obtain the throttle opening change rate in real time.

[0023] like Figure 2 As shown, in some embodiments, when the change value of the water outlet temperature of the engine within the second time interval is greater than the fifth threshold value, it is determined that the third operating condition 203 is met; when the third operating condition 203 is met and condition 202 is met, that is, the current engine water outlet temperature is greater than the first lower limit threshold value for starting the electronic fan, step 204 is executed to unlock the control of the electronic fan. For example, if the change value of the water outlet temperature of the engine is greater than 10 degrees Celsius and the water outlet temperature of the engine is greater than the first lower limit threshold value, the control of the electronic fan is unlocked. At this time, the water temperature has changed significantly, which may be because the loader has been in the transportation condition, so the throttle opening has not changed, but the water temperature continues to rise, then the fan speed can be unlocked and changed.

[0024] In some embodiments, based on the second time interval, the water outlet temperature of the engine at the initial moment of the second time interval and the water outlet temperature of the engine at the end moment are obtained, and the rate of change of the water outlet temperature of the engine in the second time interval is calculated. The processor can obtain the water outlet temperature of the engine in real time, and can calculate the water outlet temperature change value based on the timer when the second time interval is reached, so as to make a judgment. The processor can also perform calculations continuously, using each moment as the initial moment of the second time interval for calculation.

[0025] In some embodiments, when the outlet water temperature of the engine is lower than the second lower threshold for starting the electronic fan, the electronic fan is controlled to stop rotating after a third time interval, and the second lower threshold is lower than the first lower threshold. The second lower threshold may be the first lower threshold -5°C, that is, the electronic fan is not used for heat dissipation when the outlet water temperature of the engine is low.

[0026] The fourth threshold, the fifth threshold and the second lower threshold can be set according to the actual operation of the loader. If the engine outlet water temperature is greater than the first lower threshold, the electronic fan can be in the first speed level; if the engine outlet water temperature is higher, the corresponding electronic fan can be in the second speed level.

[0027] In some embodiments, the water outlet temperature of the engine is less than the first preset threshold value for starting the electronic fan, including: obtaining the water outlet temperature of the engine, timing with a timer, and determining that the water outlet temperature of the engine is less than the first preset threshold value for starting the electronic fan when the water outlet temperature of the engine corresponding to each moment in the fourth time interval is less than the first preset threshold value for starting the electronic fan. For example, if the water outlet temperature of the engine obtained every second for 10 consecutive seconds is greater than 20 degrees Celsius, it is determined that the water outlet temperature of the engine is greater than the first preset threshold value for starting the electronic fan.

[0028] According to an embodiment of the present application, a control system for a loader electronic fan is also provided. Figure 3 As shown, the control system 300 includes a processor 301, and the processor 301 is configured to: obtain the throttle opening, hydraulic motor load rate and travel motor load rate of the loader's engine; determine that the first operating condition is met when the throttle opening is greater than a first threshold, and the hydraulic motor load rate is greater than a second threshold or the travel motor load rate is greater than a third threshold; determine whether the current engine water outlet temperature is greater than a first lower threshold for starting the electronic fan based on the current engine water outlet temperature; unlock the control of the electronic fan when the first operating condition is met and the current engine water outlet temperature is greater than the first lower threshold for starting the electronic fan; when the control of the electronic fan is unlocked, determine the changed speed of the electronic fan according to the current water outlet temperature and a preset relationship between the water outlet temperature and the speed; and determine the PWM duty cycle based on the changed speed.

[0029] In some embodiments, the processor 301 is further configured to: determine that the second operating condition is met when the rate of change of the throttle opening is greater than a fourth threshold within a first time interval; and unlock the control of the electronic fan when the second operating condition is met and the current engine water outlet temperature is greater than the first lower limit threshold for starting the electronic fan.

[0030] In some embodiments, the throttle opening at the initial moment and the throttle opening at the end moment corresponding to the first time interval are obtained, and the throttle opening change rate of the first time interval is calculated.

[0031] In some embodiments, the processor 301 is further configured to: determine that the third operating condition is met when the rate of change of the engine water outlet temperature within the second time interval is greater than a fifth threshold; and unlock the control of the electronic fan when the third operating condition is met and the current engine water outlet temperature is greater than the first lower limit threshold for starting the electronic fan.

[0032] In some embodiments, based on the second time interval, the engine water outlet temperature at the initial moment and the engine water outlet temperature at the end moment of the second time interval are obtained, and the engine water outlet temperature change rate of the second time interval is calculated.

[0033] In some embodiments, the processor 301 is further configured to: control the electronic fan to stop rotating after a third time interval when the water outlet temperature of the engine is lower than a second lower limit threshold for starting the electronic fan, and the second lower limit threshold is lower than the first lower limit threshold.

[0034] In some embodiments, the water outlet temperature of the engine is greater than the first preset threshold for starting the electronic fan, including: obtaining the water outlet temperature of the engine, timing with a timer, and determining that the water outlet temperature of the engine is less than the first preset threshold for starting the electronic fan when the water outlet temperature of the engine corresponding to each moment in a fourth time interval is less than the first preset threshold for starting the electronic fan.

[0035] In some embodiments, the processor 301 can be a central processing unit (CPU), a microcontroller unit (MCU), or other general-purpose processors, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc.

[0036] According to an embodiment of the present application, a non-transitory computer-readable medium is also provided, on which instructions are stored. When executed by a processor, the instructions execute the steps of the method for controlling the electronic fan of a loader as described in any embodiment of the present application.

[0037] In addition, although exemplary embodiments have been described herein, the scope includes any and all embodiments based on the present application with equivalent elements, modifications, omissions, combinations (e.g., various embodiments intersecting schemes), adaptations or changes. The elements in the claims are to be interpreted broadly based on the language adopted in the claims, and are not limited to the examples described in this specification or during the practice of this application, and the examples are to be interpreted as non-exclusive. Therefore, this specification and examples are intended to be considered as examples only, and the true scope and spirit are indicated by the following claims and the full scope of their equivalents.

[0038] The above description is intended to be illustrative rather than restrictive. For example, the above examples (or one or more schemes thereof) may be used in combination with each other. For example, a person of ordinary skill in the art may use other embodiments when reading the above description. In addition, in the above-mentioned specific embodiments, various features may be grouped together to simplify the present application. This should not be interpreted as an intention that a feature of an application that does not require protection is necessary for any claim. On the contrary, the subject matter of the present application may be less than all the features of an embodiment of a particular application. Thus, the following claims are incorporated herein in the specific embodiments as examples or embodiments, wherein each claim is independently a separate embodiment, and it is considered that these embodiments may be combined with each other in various combinations or arrangements. The scope of the present invention should be determined with reference to the appended claims and the full scope of equivalent forms granted by these claims.

[0039] The above embodiments are only exemplary embodiments of the present application and are not intended to limit the present invention. The protection scope of the present invention is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present invention within the essence and protection scope of the present application, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present invention.

Claims

1. A method for controlling an electronic fan of a loader, characterized in that: The control method comprises: Obtain the throttle opening, hydraulic motor load rate and travel motor load rate of the loader's engine; When the throttle opening is greater than the first threshold, and the hydraulic motor load rate is greater than the second threshold or the travel motor load rate is greater than the third threshold, it is determined that the first working condition is met; Based on the current engine outlet water temperature, determining whether the current engine outlet water temperature is greater than a first lower limit threshold for starting the electronic fan; When the first operating condition is met and the current engine outlet water temperature is greater than the first lower limit threshold for starting the electronic fan, unlocking the control of the electronic fan; When the control of the electronic fan is unlocked, the changed speed of the electronic fan is determined according to the current outlet water temperature and the preset relationship between the outlet water temperature and the speed; and the PWM duty cycle is determined based on the changed speed.

2. The control method according to claim 1, characterized in that: If the rate of change of the throttle opening is greater than a fourth threshold value within the first time interval, it is determined that the second operating condition is met; if the second operating condition is met and the current engine water outlet temperature is greater than the first lower limit threshold value for starting the electronic fan, the control of the electronic fan is unlocked.

3. The control method according to claim 2, characterized in that: The throttle opening at the initial moment and the throttle opening at the end moment corresponding to the first time interval are obtained, and the throttle opening change rate of the first time interval is calculated.

4. The control method according to claim 1, characterized in that: When the rate of change of the outlet water temperature of the engine within the second time interval is greater than a fifth threshold, it is determined that the third operating condition is met; When the third operating condition is met and the current engine outlet water temperature is greater than the first lower limit threshold for starting the electronic fan, the control of the electronic fan is unlocked.

5. The control method according to claim 4, characterized in that: Based on the second time interval, the engine water outlet temperature at the initial moment and the engine water outlet temperature at the end moment of the second time interval are obtained, and the engine water outlet temperature change rate of the second time interval is calculated.

6. The control method according to claim 1, characterized in that: When the water outlet temperature of the engine is lower than a second lower threshold for starting the electronic fan, the electronic fan is controlled to stop rotating after a third time interval, and the second lower threshold is lower than the first lower threshold.

7. The control method according to claim 1, characterized in that: The water outlet temperature of the engine is greater than the first preset threshold for starting the electronic fan, including: obtaining the water outlet temperature of the engine, timing with a timer, and determining that the water outlet temperature of the engine is less than the first preset threshold for starting the electronic fan when the water outlet temperature of the engine corresponding to each moment in a fourth time interval is less than the first preset threshold for starting the electronic fan.

8. A control system for an electronic fan of a loader, characterized in that: The control system includes a processor configured to: Obtain the throttle opening, hydraulic motor load rate and travel motor load rate of the loader's engine; When the throttle opening is greater than the first threshold, and the hydraulic motor load rate is greater than the second threshold or the travel motor load rate is greater than the third threshold, it is determined that the first working condition is met; Based on the current engine outlet water temperature, determining whether the current engine outlet water temperature is greater than a first lower limit threshold for starting the electronic fan; When the first operating condition is met and the current engine outlet water temperature is greater than the first lower limit threshold for starting the electronic fan, unlocking the control of the electronic fan; When the control of the electronic fan is unlocked, the changed speed of the electronic fan is determined according to the current outlet water temperature and the preset relationship between the outlet water temperature and the speed; and the PWM duty cycle is determined based on the changed speed.

9. The control system according to claim 8, characterized in that: The processor is also configured to: determine that the second operating condition is met when the rate of change of the throttle opening is greater than a fourth threshold within a first time interval; and unlock the control of the electronic fan when the second operating condition is met and the current engine water outlet temperature is greater than a first lower limit threshold for starting the electronic fan.

10. A non-transitory computer-readable medium having instructions stored thereon, which, when executed by a processor, execute the steps of the method for controlling an electronic fan of a loader according to any one of claims 1 to 7.

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