JPH0830429B2 - Bulldozer Dosing Control Method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dosing control method for a bulldozer, which controls vehicle speed and traction force so as to adapt to dosing work under a relatively light load.

Conventional technology: The engine output of the bulldozer is set to the required value by manual operation by the main control lever, and the engine output set by this main control lever is reduced by depressing the deceleration pedal and set by returning the deceleration pedal to its original position. The required output is restored.

The pulling force during operation of the bulldozer is related to the shoe slip ratio that occurs between the track and the ground. The higher the shoe slip ratio, the more the pulling force is generated, but there is a limit. However, the engine output of the bulldozer is not effectively used as a traction force, which causes not only energy loss but also trouble such as wear of the track in a short period of time.

When shoe slip (crawler track slip) occurs excessively, the operator conventionally senses this and depresses the deceleration pedal to reduce the engine output, and at the same time operates the work machine to reduce the load to reduce the traction force. , The shoe slip had been resolved. Then, when the shoe slip is eliminated, the depression of the deceleration pedal has to be loosened or returned to the original value to restore the engine output to a preset steady output.

The shoe slip control by the operator's operation is performed by the operator knowing the occurrence of the shoe slip visually and sensually, reducing the load by operating the working machine and cutting off the engine output by operating the deceleration pedal. Therefore,
The operator's operation is complicated and requires careful attention, and the difference depending on the skill of the operator has a great influence. Even in the case of a well-trained operator, it is inevitable that there is a time lag between the occurrence of shoe slip and the operator's operation, and some operators often slip unnecessarily. It is difficult to achieve the purpose of preventing this. Further, when operating the work machine, the engine output based on the normal shoe slip ratio may not match the actual work, and in such a case, power adjustment by operating the deceleration pedal was necessary.

Problems to be solved: Of the work of the bulldozer, when the shoe slip occurs during dosing, the operator first controls by operating the work machine, and even if the shoe slip becomes excessive, the operator depresses the deceleration pedal. There is a tendency that narrowing the output does not match the operation feeling of the operator.

Among the dozing, soft rock dosing has a power load intermediate between ripping and sandy dosing, and because large-scale soil excavation is not performed, it tends to have high traction and low vehicle speed. As a result, the vehicle speed is too fast in the full mode represented by the traction force-velocity diagram, (1) the riding comfort is poor, (2) the blade does not easily bite into the soil, and only the surface of the bedrock is rubbed. (3) There were problems such as the blade operation not keeping up with the vehicle speed.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is a bulldozer in which control is automatically performed with cutoff of engine output and cancellation of cutoff according to shoe slip ratio, vehicle speed, and traction force. Regarding the above, it is an object of the present invention to provide a dosing control method for a bulldozer which can automatically shift to a preset low output mode when performing a light load dosing work and obtain an engine output adapted to the target work.

Means for Solving the Problems: In order to achieve the above-mentioned object, a dosing control method for a bulldozer according to the present invention is a dozing control method for a bulldozer, which transmits an engine output to a sprocket wheel through a torque converter to drive a crawler track. Therefore, multiple engine output modes are set by cutting the high output part of the full output curve in the traction-speed diagram that represents the output state of the engine and stored in the output control system. Of the plurality of engine output modes depending on the load, at least two engine output modes for forward traveling and at least two engine output modes for backward traveling corresponding to the at least two engine output modes are selected. Allows you to select the engine power mode and Giving automatically command the fuel injection pump in response to the down output mode, it is characterized in that to obtain an engine output required to achieve the desired work.

In the present invention, the final fuel injection pump command is obtained by selecting a small signal from the command signal to the fuel injection pump and either the deceleration pedal operation signal or the throttle lever operation signal. preferable.

Effects and Effects of the Invention In the present invention, during dosing work with a comparatively light load, among a plurality of engine output modes in which the high output portion of the full output curve in the traction-speed diagram is cut by the mode selection switch It is possible to select an appropriate output mode of. In this way, a command is issued to the fuel injection pump so that the engine output is adapted to the selected output mode, and the relatively light load dosing such as soft rock dosing is smoothly performed. In this case, at least two engine output modes during reverse traveling can be selected so as to correspond to at least two engine output modes during forward traveling, respectively. The running is smooth.

As a result, except when it is indispensable for work operation, unnecessary slip due to excessive output is reduced, the suspension life is improved, and fuel consumption can be improved. Further, the frequency of the deceleration pedal operation can be remarkably reduced, and the burden on the operator can be reduced.

In the present invention, when the final fuel injection pump command is obtained by selecting a small signal from the command signal to the fuel injection pump and either the deceleration pedal operation signal or the throttle lever operation signal, the operator Safety can be ensured by prioritizing manual operation.

Examples: Hereinafter, specific examples for carrying out the method of the present invention will be described.

For example, in the work operation of a bulldozer having a working machine such as dozing and ripping, the relationship between the traction force F and the vehicle speed V is represented by a traction force-speed diagram as shown in FIG. In this traction-velocity diagram, when the engine is at full output, the curve is similar to the full output curve indicated by the broken line. The point at which the full output curve of this engine intersects with the X axis indicating speed is the upper limit of vehicle speed, and the point at which it intersects with the Y axis indicating tractive force is the upper limit of tractive force. The pulling force of the bulldozer is related to the shoe slip ratio, and the effective maximum pulling force is obtained at a constant shoe slip ratio. Therefore,
The traction force and the vehicle speed including these factors are based on the basic mode in which the high output part is cut in order to prevent unnecessary slip and obtain an effective traction force depending on the soil / rock quality or working conditions. Setting the engine output is meaningful.

As described above, the load of soft rock dosing after ripping is lighter than that of sandy dozing. Therefore, the Hi mode or Lo mode is set with a narrower output than the basic mode, and the operator can select the engine output mode such as the Hi mode or Lo mode according to the load of the dosing by the mode selection switch. . In Fig. 2, the traction force corresponding to the origin when Hi mode is selected is FHi, and similarly in Lo mode it is FLo.
(In the basic mode, it becomes F). In this embodiment, FHi and FLo are set as follows with respect to the throttle command value W with which the traction force F is obtained in the basic mode.

FHi ~ 0.9W FLo ~ 0.8W Corresponding to the Hi mode and Lo mode for forward running during this dosing work, the traction force control for reverse running is shown in the Hi mode and Lo mode of Fig. 3 for the engine. It can be done in output mode.

In the actual work operation, if the main switch is set to dosing control and the operating lever of the working machine is set to dosing, the adaptive engine output mode in the control target diagram is selected according to the load of this operation. Then, a command is given to the fuel injection pump for this selected mode, and an engine output adapted to the target work is obtained.

A series of these behaviors can be automatically advanced according to a control stage including requirements corresponding to each work condition as illustrated in FIG. In this control stage diagram, the mode selection based on the control target diagram is controlled according to the engine output mode in the state shown in the traction force-speed diagram shown in FIG. 2 or 3.

Further, in the method of the present invention, in order to respond to a slight change during the dosing operation, the operator issues a signal command by operating the throttle lever or the deceleration pedal to select it as a small signal, and has priority over the mode selection according to the control target diagram. Then, the combustion injection pump is instructed to obtain a desired engine speed, and smoothness of dosing work and safety measures are maintained.

[Brief description of drawings]

FIG. 1 is a control step diagram showing a specific example of the method of the present invention, and FIGS. 2 and 3 are control target diagrams of the control step diagram of FIG.
FIG. 2 is a diagram showing the engine output mode at the time of dosing forward movement, and FIG. 3 is a diagram showing the engine output mode at the time of reverse traveling.

Claims (2)

[Claims] 1. A dosing control method for a bulldozer for transmitting engine output to a sprocket wheel via a torque converter to drive a crawler belt, wherein a full output curve height in a traction force-speed diagram representing an engine output state. Of the multiple engine output modes among the multiple engine output modes set by the mode selection switch according to the load during dozing work, the engine output modes of the multiple output types are set and stored in the output control system. At least two engine output modes and at least two engine output modes corresponding to the at least two engine output modes at the time of reverse traveling are selectable, and automatic selection is performed according to the selected engine output modes. To instruct the fuel injection pump to achieve the desired work. Bulldozer dosing control method characterized by obtaining the engine output. 2. A final fuel injection pump command is obtained by selecting a small signal from the command signal to the fuel injection pump and either the deceleration pedal operation signal or the throttle lever operation signal. Claim 1
A bulldozer dosing control method according to claim 1.