Engine load protection method in tractor PTO operation process

Abstract

The invention discloses an engine load protection method in the tractor PTO operation process. The method comprises the following steps that an ECU obtains the actual engine torque; the GCU obtains the actual generator torque; the HCU obtains PTO torque according to a torque distribution rule by combining the actual engine torque and the actual generator torque; the HCU obtains the current maximum output torque of the engine according to the PTO torque; the HCU obtains the change trend of the actual engine torque, and when the actual engine torque exceeds the current maximum output torque of the engine, a torque control instruction is generated and sent to the GCU and the MCU; and the MCU and the GCU execute corresponding operation required by the torque control instruction according to the torque control instruction. According to the invention, the engine torque can be regulated and controlled in advance; the engine torque is reduced, normal operation of a carrier and an agricultural implement is kept to the maximum extent, and the engine is protected from rotating speed pressing and even flameout.

Description

Technical Field

[0001] The invention relates to the field of EMCVT tractor PTO operation, in particular to an engine load protection method during tractor PTO operation. Background Art

[0002] When the existing hybrid tractor uses PTO for operation, the engine takes into account both power generation and power output. The power generation provided by the engine is far higher than the power range of the agricultural machinery connected to the PTO operation. Therefore, a slight change in the torque provided by the engine will cause a significant change in the PTO torque load. If the power generation torque plus the PTO torque is greater than the maximum output torque of the engine, it exceeds the external characteristics of the engine, which can easily cause the engine to overspeed or even stall.

[0003] When the tractor PTO is in operation, there may be a situation where the engine stalls due to external characteristics, and the prior art does not provide a technical solution to this problem.

[0004] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0005] The purpose of the present invention is to provide an engine load protection method during tractor PTO operation, which can solve the problems existing in the background technology.

[0006] To achieve the above-mentioned purpose, the present invention provides an engine load protection method during tractor PTO operation, characterized in that it includes the following steps: S100: ECU loads engine torque and engine load rate; S200: the whole vehicle enters PTO working condition; S300: ECU obtains actual engine torque; S400: GCU obtains actual generator torque; S500: HCU combines the actual engine torque and the actual generator torque, and obtains PTO torque according to torque distribution rules; S600: HCU obtains the current maximum output torque of the engine according to the PTO torque; S700: HCU obtains the change trend of the actual engine torque, and when the actual engine torque will exceed the current maximum output torque of the engine, generates a torque control instruction and sends it to GCU and MCU; S800: MCU and GCU execute the corresponding operation required by the torque control instruction according to the torque control instruction; wherein, the ECU refers to the engine controller; the HCU refers to the hybrid controller; the GCU refers to the generator controller; and the MCU refers to the drive motor controller.

[0007] In one or more embodiments, the step S100 includes: S110: ECU obtains target output torque and power values; S120: ECU adjusts current output torque and power values ​​based on the target output torque and power values ​​until the current output torque and power values ​​are equal to the target output torque and power values; wherein the target output torque and power values ​​are derived from values ​​determined by ECU based on factors such as engine gear position and driver operation.

[0008] In one or more embodiments, the step S200 includes: adjusting the transmission mechanism to mechanically connect the agricultural implement to the transmission mechanism.

[0009] In one or more embodiments, the step S300 includes: the ECU obtains the actual engine torque based on the engine speed and output power.

[0010] In one or more embodiments, the step S400 includes: the GCU obtains the actual generator torque based on data collected by the sensor.

[0011] In one or more embodiments, the step S500 includes: S510: HCU queries the actual engine torque and the actual generator torque; S520: HCU determines the PTO torque according to the PTO torque distribution rule; S530: MCU loads the PTO torque; S540: MCU distributes the current output torque and power value to the agricultural machinery.

[0012] In one or more embodiments, the step S520 includes: S521: the HCU calculates the actual engine torque minus the actual generator torque to obtain a calculation result; S522: the HCU writes the calculation result into the PTO torque.

[0013] In one or more embodiments, the step S600 includes: S610: the HCU obtains the current engine speed load rate; S620: the HCU obtains the engine external characteristics; S630: the HCU obtains the current engine maximum output torque based on the current engine speed load rate and the PTO torque.

[0014] Compared with the prior art, the multiple technical solutions and embodiments provided by the present invention have at least the following technical effects or advantages:

[0015] By estimating the time when the engine load exceeds the external characteristics, the engine torque can be pre-regulated; by intelligently changing the PTO torque and generator torque, the engine torque can be reduced while maintaining the normal operation of the vehicle and agricultural machinery to the maximum extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and can be considered as illustrative of various combinations of preferred embodiments and do not constitute an improper limitation on the present invention. In the drawings:

[0017] Figure 1 The present invention provides an overall flow chart of an engine load protection method during tractor PTO operation. DETAILED DESCRIPTION

[0018] Unless explicitly stated otherwise, throughout the specification and claims, the term "comprise" or its variations such as "include" or "comprising", "made of", etc. will be understood to include the stated elements or components but not to exclude other elements or other components.

[0019] The purpose of the present invention is to provide an engine load protection method during tractor PTO operation, so as to achieve the effect of protecting the engine from speed reduction or even flameout under PTO working conditions with variable torque distribution.

[0020] Embodiment 1:

[0021] The present embodiment provides an engine load protection method during the PTO operation of a tractor, characterized in that it includes the following steps: S100: ECU loads the engine torque and the engine load rate; S200: the whole vehicle enters the PTO working condition; S300: ECU obtains the actual engine torque; S400: GCU obtains the actual generator torque; S500: HCU combines the actual engine torque and the actual generator torque, and obtains the PTO torque according to the torque distribution rule; S600: HCU obtains the current maximum engine output torque according to the PTO torque; S700: HCU obtains the change trend of the actual engine torque, and when the actual engine torque will exceed the current maximum engine output torque, generates a torque control instruction and sends it to the GCU and MCU; S800: MCU and GCU execute the corresponding operations required by the torque control instruction according to the torque control instruction; wherein, the ECU refers to the engine controller; the HCU refers to the hybrid controller; the GCU refers to the generator controller; and the MCU refers to the drive motor controller.

[0022] Specifically, when a special vehicle (such as a tractor, a harvester, etc.) driven by a diesel engine enters a PTO condition, in order to save space for arranging an additional power mechanism, part of the engine's torque is allocated to the agricultural machinery. The power of the vehicle is provided by the engine-generator-motor. However, the engine torque is not actively loaded to the generator. The motor controller makes the motor add torque in the opposite direction. In order to maintain the speed, the engine needs to increase the torque. The program strategy has corrected the mechanical load part, so the sum of the generator torque and the PTO torque is equal to the engine torque output. When the generator torque and the PTO torque change greatly, it is easy to cause the engine to exceed the external characteristic operation, resulting in a pressure speed or even a flameout. In order to protect the engine from the effect of pressure speed or even flameout under the PTO condition with variable torque distribution, this embodiment provides an engine load protection method during the tractor PTO operation process. By calculating the sum of the generator torque and the PTO torque to determine whether the engine torque reaches the external characteristic, the HCU generates a torque control instruction, the torque control instruction provides the change strategy of the actual generator torque and the PTO torque, and the system executes the torque control instruction for pre-intervention to avoid the engine exceeding the external characteristic.

[0023] As a preferred implementation manner of this embodiment, the step S100 includes: S110: ECU obtains target output torque and power values; S120: ECU adjusts current output torque and power values ​​based on the target output torque and power values ​​until the current output torque and power values ​​are equal to the target output torque and power values; wherein the numerical values ​​of the target output torque and power values ​​are derived from the fact that the ECU determines them based on factors such as engine gear position and driver operation.

[0024] Specifically, the operation of the vehicle requires that part of the engine torque be allocated to the PTO torque. By setting the required target output torque and power value, the ECU issues an adjustment command to adjust the current output torque and power value, and gradually approaches the current output torque. The significance of setting the target output torque is to prevent the engine from exceeding the external characteristics when it is started. The target output torque is controlled within the external characteristics to ensure that the engine starts normally until it enters the PTO condition.

[0025] As a preferred implementation of this embodiment, the step S200 includes: adjusting the transmission mechanism to mechanically connect the agricultural implement to the transmission mechanism. Preferably, the step S300 includes: the ECU obtains the actual engine torque based on the engine speed and output power. Preferably, the step S400 includes: the GCU obtains the actual generator torque based on the data collected by the sensor.

[0026] Specifically, in order to determine the PTO torque, the agricultural implement needs to be mechanically connected via a transmission mechanism so as to enter the PTO working condition, and the actual engine torque and the actual generator torque are obtained to further calculate the PTO torque.

[0027] As a preferred implementation of this embodiment, the step S500 includes: S510: HCU queries the actual engine torque and the actual generator torque; S520: HCU determines the PTO torque according to the PTO torque distribution rule; S530: MCU loads the PTO torque; S540: MCU distributes the current output torque and power value to the agricultural machinery. Preferably, the step S520 includes: S521: HCU calculates the actual engine torque minus the actual generator torque to obtain a calculation result; S522: HCU writes the calculation result into the PTO torque.

[0028] Specifically, in order to load the PTO torque to the agricultural implement, the program strategy in this embodiment has corrected the mechanical load, so the PTO torque can be equal to the actual engine torque minus the actual generator torque, and the calculation result is obtained, and the calculation result is the PTO torque. This calculation method is used as the PTO torque distribution rule to obtain the PTO torque value for subsequent judgment of whether the engine torque has a tendency to exceed the external characteristic.

[0029] As a preferred implementation of this embodiment, the step S600 includes: S610: HCU obtains the current engine speed load rate; S620: HCU obtains the engine external characteristics; S630: HCU obtains the current engine maximum output torque based on the current engine speed load rate and PTO torque.

[0030] Specifically, the HCU can obtain the load rate at the current engine speed according to the sensor information, and obtain the current maximum output torque of the engine by dividing the current engine speed load rate by the current engine torque according to the calculation formula of the load rate.

[0031] As a preferred implementation manner of this embodiment, the step S700 includes: S710: HCU records the actual engine torque for multiple times and obtains the engine torque recording time; S720: HCU obtains the engine torque change rate based on the engine torque recording time and the value of the actual engine torque, and generates the change trend of the actual engine torque; S730: HCU predicts the time required for the actual engine torque to reach the current engine maximum output torque based on the change trend of the actual engine torque and the engine torque; S740: When the required time is a negative value, the HCU continuously monitors the engine torque change; when the required time is a positive value, the correction torque time and the correction torque amplitude are determined according to the required time value, and according to the correction torque time and the correction torque amplitude, the HCU generates a torque control instruction and sends it to the GCU and MCU.

[0032] Specifically, in order to avoid the engine from overspeeding or even stalling, the HCU estimates the state of the engine based on the PTO torque and the engine load rate. The estimation includes obtaining the rate of change of the engine load rate, that is, the rate of change of the current engine torque, and calculating the engine load rate and time difference at different times. The time when the engine load rate reaches the upper limit is estimated by combining the current engine load rate with the engine load rate change rate. When the sum of the actual power generation torque and the PTO torque increases, the engine load rate approaches the upper limit. This embodiment achieves the purpose of reducing the engine torque by intelligently changing the actual power generation torque and the PTO torque. The HCU performs differentiated operations by judging the type of agricultural machinery output by the PTO, as follows:

[0033] (1) When the agricultural implement driven by the PTO is of a heavy load type (such as a rotary tiller), the vehicle speed requirement is generally not high under this working condition. The engine protection is achieved by slightly changing the PTO torque and significantly reducing the power generation torque. The above adjustment strategy can significantly reduce the power generation torque and thus reduce the engine load, preventing the engine from stalling. At the same time, a slower vehicle speed can ensure the effect of soil crushing.

[0034] (2) When the PTO-driven agricultural machinery has a light load (such as a baler), medium to high vehicle speeds are generally required under this operating condition. The engine protection is achieved by significantly reducing the PTO torque and slightly changing the power generation torque. The above adjustment strategy can significantly reduce the PTO torque, thereby reducing the engine load. When the engine is fully loaded, the optimal vehicle operating condition can be automatically found.

[0035] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.

Claims

1. A method for protecting engine load during tractor PTO operation, characterized in that: The steps include: S100: ECU loads engine torque and engine load rate; S200: The vehicle enters PTO mode; S300: ECU obtains actual engine torque; S400: GCU obtains actual generator torque; S500: The HCU combines the actual engine torque and the actual generator torque and obtains the PTO torque according to a torque distribution rule; S600: The HCU obtains the current maximum output torque of the engine according to the PTO torque; S700: The HCU obtains the change trend of the actual engine torque, and when the actual engine torque is about to exceed the current maximum output torque of the engine, generates a torque control instruction and sends it to the GCU and the MCU; S800: The MCU and the GCU execute corresponding operations required by the torque control instruction according to the torque control instruction; Among them, the ECU refers to the engine controller; the HCU refers to the hybrid controller; the GCU refers to the generator controller; and the MCU refers to the drive motor controller.

2. The method for protecting engine load during tractor PTO operation as claimed in claim 1, characterized in that: The step S100 includes: S110: ECU obtains target output torque and power values; S120: The ECU adjusts the current output torque and power value based on the target output torque and power value until the current output torque and power value is equal to the target output torque and power value; The target output torque and power values ​​are derived from values ​​determined by the ECU based on factors such as engine gear position and driver operation.

3. The method for protecting engine load during tractor PTO operation as claimed in claim 1, characterized in that: The step S200 includes: The transmission mechanism is adjusted to mechanically connect the agricultural implement to the transmission mechanism.

4. The method for protecting engine load during tractor PTO operation as claimed in claim 1, characterized in that: The step S300 includes: The ECU obtains the actual engine torque based on the engine speed and output power.

5. The method for protecting engine load during tractor PTO operation as claimed in claim 1, characterized in that: The step S400 includes: The GCU obtains the actual generator torque based on the data collected by the sensor.

6. The method for protecting engine load during tractor PTO operation as claimed in claim 1, characterized in that: The step S500 includes: S510: The HCU queries the actual engine torque and the actual generator torque; S520: The HCU determines the PTO torque according to a PTO torque distribution rule; S530: MCU loads the PTO torque; S540: The MCU distributes the current output torque and power values ​​to the agricultural implement.

7. The method for protecting engine load during tractor PTO operation as claimed in claim 6, characterized in that: The step S520 includes: S521: The HCU calculates the actual engine torque minus the actual generator torque to obtain a calculation result; S522: The HCU writes the calculation result into the PTO torque.

8. The method for protecting engine load during tractor PTO operation as claimed in claim 1, characterized in that: The step S600 includes: S610: The HCU obtains the current engine speed load rate; S620: HCU obtains external characteristics of the engine; S630: The HCU obtains the current maximum output torque of the engine based on the current engine speed load rate and the PTO torque.

9. The method for protecting engine load during tractor PTO operation as claimed in claim 6, characterized in that: The step S700 includes: S710: The HCU records multiple actual engine torques and obtains the engine torque recording time; S720: The HCU obtains the engine torque change rate according to the engine torque recording time and the actual engine torque value, and generates a change trend of the actual engine torque; S730: The HCU predicts the time required for the actual engine torque to reach the current maximum output torque of the engine according to the change trend of the actual engine torque and the engine torque; S740: When the required time is a negative value, the HCU continuously monitors the change of the engine torque; when the required time is a positive value, the corrected torque time and the corrected torque amplitude are determined according to the required time value, and according to the corrected torque time and the corrected torque amplitude, the HCU generates a torque control instruction and sends it to the GCU and MCU.

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