A hydrostatic loader downhill anti-over-speed control system

Abstract

The present invention relates to the technical field of loader anti - overspeed control, and specifically to a hydrostatic loader downhill anti - overspeed control system. The system includes an ECU and a TCU. An anti - overspeed protection function is set in the system. The ECU collects the engine speed and interacts with the TCU. The TCU collects the whole vehicle speed and the whole vehicle gear position. The TCU decides whether to operate the speed - reduction protection according to the written overspeed protection strategy. Conditions for operating the speed - reduction protection: The whole vehicle gear position is in the high - speed gear; the engine speed is greater than the limit value n min ; the whole vehicle speed is greater than the speed - reduction starting value V min , V min is greater than the vehicle speed corresponding to the maximum engine speed n max when the whole machine is operating on flat ground. When all the above three operating conditions are met, the TCU operates the speed - reduction protection to make the ECU control the engine to reduce speed for anti - overspeed protection of the whole machine. In the overspeed protection strategy, the speed - reduction end value V min when the vehicle speed is greater than V max is also set. When the TCU operates the speed - reduction protection to reduce the engine speed, before the vehicle speed rises to V max , the ECU controls the engine speed to drop to n min .

Description

Technical Field

[0001] The present invention relates to the technical field of anti - overspeed control for loaders, and specifically to an anti - overspeed control system for a hydrostatic loader when going downhill. Background Art

[0002] During the driving process of a loader, when encountering a steep downhill slope, the whole vehicle will slide under the action of its own weight. If the driver is still driving at full throttle at this time, the whole vehicle will run faster and faster, resulting in the vehicle overspeed; for hydrostatic models, vehicle overspeed will cause irreparable damage to the pumps and motors of the transmission system, and even cause the whole vehicle to malfunction during driving, and then it cannot work properly. Summary of the Invention

[0003] The purpose of the present invention is to provide an anti - overspeed control system for a hydrostatic loader that can effectively prevent the whole vehicle from overspeed when the loader goes downhill and causes the whole vehicle to accelerate, and thus effectively prevent the pumps and motors from being damaged due to overspeed.

[0004] To achieve the above - mentioned purpose, the present invention discloses an anti - overspeed control system for a hydrostatic loader, which includes an ECU and a TCU. An anti - overspeed protection function is set in the system. The ECU collects the engine speed and interacts with the TCU. The TCU collects the vehicle speed and the gear of the whole vehicle. The TCU decides whether to operate the speed - reduction protection according to the written overspeed protection strategy:

[0005] Operating conditions for speed - reduction protection:

[0006] (1) The whole - vehicle gear is in the high - speed gear;

[0007] (2) The engine speed is greater than the limit value n min ;

[0008] (3) The vehicle speed of the whole vehicle is greater than the speed - reduction starting value V min , V min is greater than the vehicle speed corresponding to the maximum engine speed n max when the whole vehicle is operating on flat ground.

[0009] When all the above three operating conditions are met, the TCU operates the speed - reduction protection so that the ECU controls the engine to reduce speed to protect the whole vehicle from overspeed.

[0010] In the overspeed protection strategy, the speed - reduction end value V min when the vehicle speed is greater than V max is also set. After the TCU operates the speed - reduction protection to reduce the engine speed, before the vehicle speed rises to V max , the ECU controls the engine speed to drop to n min .

[0011] In the overspeed protection strategy, it is also set that when the vehicle speed is less than V minThe safety value V s After the TCU runs the speed reduction protection to reduce the engine speed to n min , its speed is always limited to n min until the whole vehicle speed is less than V s , the engine cancels the speed limit and resumes the original speed.

[0012] Preferably, both the ECU and the TCU are connected to the CAN bus. When all three operating conditions are met, the specific process of the TCU running the speed reduction protection is as follows: The TCU sends a TSC1 message and sends it to the ECU in the form of a CAN bus message, and the ECU controls the engine to reduce speed.

[0013] Preferably, it further includes a key panel and an instrument connected to the CAN bus. When all three operating conditions are met, while the TCU runs the speed reduction protection, it sends an overspeed alarm message to the instrument. After that, when the whole vehicle speed is less than V s , the engine cancels the speed limit and the speed resumes to n max , the TCU cancels the alarm of the instrument. When the loader is overspeed, it can enable the driver to clearly know the current state of the loader so that the driver can make preparations for subsequent operations.

[0014] Preferably, the overspeed protection strategy further includes: Before the TCU diagnoses the operating conditions, the system first detects whether the overspeed protection function is normally enabled. If it has been enabled, the TCU starts to diagnose the operating conditions along with the operation of the whole machine. If it has not been enabled, the TCU sends an alarm message that the overspeed protection function is not normally enabled to the instrument and can select whether to continue the operation through the key panel. If the selection is yes, the engine runs at the normal working speed. If the selection is no, stop for maintenance. It can timely check and repair when the anti-overspeed protection function of the system fails, ensuring the normal activation of the system's anti-overspeed protection function.

[0015] Preferably, after the loader is powered on and started, first select whether to enable the overspeed protection function through the key panel and the instrument.

[0016] Preferably, the whole machine is default to enable the overspeed protection function when leaving the factory.

[0017] Preferably, n min is 1600 rpm, n max is 2300 rpm, V min is 40 km / h, V max is 42 km / h, V s is 37 km / h.

[0018] Preferably, the parameter values n min , n max , V min , V max and V sIt is set at the time of the whole machine leaving the factory, or can be set through the intelligent key panel and the instrument by means of authorization.

[0019] The beneficial effects of the present invention are as follows: The control system disclosed in the present invention, according to the anti-over-speed protection function set therein, utilizes the reverse drag braking after the engine of the hydrostatic system decelerates, that is, the deceleration of the engine is used to absorb the kinetic energy of the whole machine to achieve the effect of deceleration, which can effectively prevent the whole machine from over-speeding when the loader is going downhill and causing the whole machine to accelerate, and further effectively prevent the pump and the motor from being damaged due to over-speeding; greatly improve the service life of the loader and enhance the reliability of the whole machine operation. Brief Description of the Drawings

[0020] Figure 1 is the flowchart of the anti-over-speed protection function of the first embodiment of the present invention;

[0021] Figure 2 is the flowchart of the anti-over-speed protection function of the second embodiment of the present invention;

[0022] Figure 3 is the structural schematic diagram of a hydrostatic loader downhill anti-over-speed control system disclosed by the present invention. Detailed Embodiments

[0023] The following will further describe in detail the specific embodiments of the present invention in conjunction with the drawings and embodiments. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0024] The following is a description of the preferred embodiments of the present invention in conjunction with the drawings.

[0025] First Embodiment:

[0026] As Figure 3 shown, the present invention discloses a hydrostatic loader downhill anti-over-speed control system, which includes an ECU (engine controller) and a TCU (transmission controller) connected to the CAN bus. An anti-over-speed protection function is set in this system. As Figure 1 shown, the ECU collects the engine speed and interacts with the TCU. The TCU collects the vehicle speed and the gear of the whole machine. The TCU decides whether to operate the deceleration protection according to the written anti-over-speed protection strategy:

[0027] Operating conditions for deceleration protection:

[0028] (1) The gear of the whole machine is in the high gear;

[0029] (2) The engine speed is greater than the limit value n min ;

[0030] (3) The vehicle speed of the whole machine is greater than the deceleration starting value V min , V minGreater than the maximum engine speed n during the whole machine's land leveling operation max The corresponding vehicle speed.

[0031] When all of the above three operating conditions are satisfied, the TCU runs the speed reduction protection, causing the ECU to control the engine to reduce speed to protect the whole machine from overspeeding.

[0032] In this embodiment, when all three operating conditions are satisfied, the specific process of the TCU running the speed reduction protection is as follows: The TCU sends a TSC1 message, which is sent to the ECU in the form of a CAN bus message, and the ECU controls the engine to reduce speed. Specifically, the counter-dragging brake after the engine speed reduction of the hydrostatic system is utilized, that is, the engine speed reduction is used to absorb the kinetic energy of the whole machine to achieve the speed reduction effect.

[0033] In addition, the overspeed protection strategy also sets a speed reduction end value V min and a safety value V max when the vehicle speed is greater than V min and when the vehicle speed is less than V s . When the TCU runs the speed reduction protection to reduce the engine speed, before the vehicle speed rises to V max , the ECU controls the engine speed to drop to n min ; when the TCU runs the speed reduction protection to reduce the engine speed to n min , its speed is always limited to n min until the vehicle speed of the whole machine is less than V s , the engine cancels the speed limit and resumes the original speed (i.e., the normal operating speed before the engine runs the speed reduction protection).

[0034] Specifically, the specific numerical values of the above set values are as follows:

[0035] n min is 1600 rpm, n max is 2300 rpm, V min is 40 km / h, V max is 42 km / h, V s is 37 km / h.

[0036] Furthermore, the system also includes a key panel and an instrument connected to the CAN bus. When all three operating conditions are satisfied and the TCU runs the speed reduction protection, it sends an overspeed alarm message "Vehicle overspeed, please decelerate" to the instrument. After that, when the vehicle speed of the whole machine is less than V s and the engine cancels the speed limit and the speed resumes to n max , the TCU cancels the alarm on the instrument.

[0037] After the loader is powered on and started, first, it is possible to select whether to enable the overspeed protection function through the key panel and the instrument, or the whole machine defaults to enabling the overspeed protection function when leaving the factory.

[0038] Parameter value n min 、n max 、V min 、V max and V s can be set at the time of leaving the factory of the whole machine, or can be set through the intelligent key panel and the instrument by means of authorization.

[0039] Second embodiment:

[0040] As Figure 2 shown, on the basis of the above first embodiment, the overspeed protection strategy further includes: before the TCU diagnoses the operating conditions, the system first detects whether the overspeed protection function is normally turned on. If it has been turned on, the TCU starts to diagnose the operating conditions along with the operation of the whole machine. If it has not been turned on, the TCU sends the alarm message "The overspeed protection function is not normally turned on. Do you want to continue working?" to the instrument. If urgent work needs to be carried out, "Yes" can be selected on the key panel to temporarily make the engine operate at the normal working speed. If time permits for maintenance or maintenance is necessary, "No" is selected on the key panel, and then the machine is stopped for maintenance.

[0041] It should be noted that the overspeed prevention control system involved in the present invention can be applied not only to loaders, but also to other vehicles using a hydrostatic system.

[0042] The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and replacements can still be made, and these improvements and replacements should also be regarded as the protection scope of the present invention.

Claims

1. A hydrostatic loader downhill anti - overspeed control system, Characterized in that, It includes an ECU and a TCU. An anti - overspeed protection function is set in the system. The ECU collects the engine speed and interacts with the TCU. The TCU collects the whole vehicle speed and the whole vehicle gear position. The TCU decides whether to operate the speed - reduction protection according to the written overspeed protection strategy: Operating conditions for speed - reduction protection: (1) The whole vehicle gear position is in the high - speed gear; (2) The engine speed is greater than the limit value n min ; (3) The vehicle speed of the whole machine is greater than the deceleration starting value V min , V min is greater than the maximum engine speed n max corresponding to the vehicle speed during the flat operation of the whole machine; When all of the above three operating conditions are met, the TCU operates the speed - reduction protection to make the ECU control the engine to decelerate for anti - overspeed protection of the whole machine; In the overspeed protection strategy, it is also set that the vehicle speed is greater than V min The deceleration end value V max . When the TCU operates the deceleration protection to decelerate the engine, before the vehicle speed rises to V max , the ECU controls the engine speed to drop to n min ; In the overspeed protection strategy, it is also set that the vehicle speed is less than V min of the safety value V s . When the TCU runs the speed reduction protection to reduce the engine speed to n min , its speed is always limited to n min until the vehicle speed of the whole locomotive is less than V s . At this time, the engine cancels the speed limit and resumes the original speed.

2. The hydrostatic loader downhill anti - overspeed control system according to claim 1, Characterized in that, Both the ECU and the TCU are connected to the CAN bus. When all three operating conditions are met, the specific process of the TCU operating the speed - reduction protection is as follows: The TCU sends a TSC1 message and sends it to the ECU in the form of a CAN bus message, and the ECU controls the engine to decelerate.

3. The hydrostatic loader downhill anti - overspeed control system according to claim 2, Characterized in that, It also includes a key panel and an instrument connected to the CAN bus. When all three operating conditions are met, while the TCU operates the speed reduction protection, it sends an overspeed alarm message to the instrument. After that, when the vehicle speed of the whole locomotive is less than V s , the engine cancels the speed limit and the speed resumes to n max . When this happens, the TCU makes the instrument cancel the alarm.

4. The hydrostatic loader downhill anti - overspeed control system according to claim 3, Characterized in that, The overspeed protection strategy further includes: Before the TCU diagnoses the operating conditions, the system first detects whether the overspeed protection function is normally enabled. If it is enabled, the TCU starts to diagnose the operating conditions along with the operation of the whole machine. If it is not enabled, the TCU sends an alarm message that the overspeed protection function is not normally enabled to the instrument and can select whether to continue working through the key panel. If the selection is yes, the engine runs at the normal working speed. If the selection is no, the machine stops for maintenance.

5. The hydrostatic loader downhill anti - overspeed control system according to claim 3, Characterized in that, After the loader is powered on and started, first select whether to enable the overspeed protection function through the key panel and the instrument.

6. The hydrostatic loader downhill anti - overspeed control system according to claim 3, Characterized in that, The whole machine is default - enabled with the overspeed protection function when leaving the factory.

7. The hydrostatic loader downhill anti - overspeed control system according to claim 1, Characterized in that, n min is 1600 rpm, n max is 2300 rpm, V min is 40 km / h, V max is 42 km / h, V s is 37 km / h.

8. The hydrostatic loader downhill anti - overspeed control system according to claim 3, Characterized in that, Parameter value n min , n max , V min , V max and V s are set at the time of factory shipment of the whole machine, or are set through the intelligent key panel and instrument by means of authorization.

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