JPS63235631A - Engine output control means for bulldozer - Google Patents

Abstract

PURPOSE:To utilize an engine output effectively at every operation, by controlling the engine output along an output torque curve appropriate to each operation set in advance, when a bulldozer performs the other operations than an usual operation for pushing soil forward. CONSTITUTION:An engine 4 provides a fuel injection pump 8 which can control its fuel injection amount by an electronic control governor 7, and the control rack 9 of the electronic control governor 7 performs its reciprocating motion by a cylinder 10 supplied with pressure oil, through a control valve 12. The control valve 12 is controlled by an engine controller 15 responding to an operated amount of a main control lever 14. In this case, the controller 15 is provided with an engine output characteristic (output torque curve) memory portion 16, and by operating a select switch 17, it can select a bigger output torque curve in an usual operation for pushing soil forward, and also any output torque appropriate to each operation in an operation than said operation, so as to contribute to the output control.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for controlling the output of an engine mounted on a bulldozer.

[Conventional technology]

A bulldozer is equipped with an earth-moving machine such as a blade or ripper on the vehicle body, and the output side of the engine mounted on the vehicle body is connected via a power line to a sprocket that drives the tracks.The output characteristics of the engine are determined by the blades. It is usually set to match the dosing advance work machine. In other words, since a large traction force is required during the forward dozing work, the output characteristics of the engine are set to obtain a large output.

[Problem that the invention seeks to solve]

On the other hand, bulldozer work includes ripping work with a ripper and running backwards, and during ripping work, the traction force may be too large, causing the tracks to slip on the road surface, or in other words, track slippage. When track slipping occurs, engine output cannot be used effectively, fuel is wasted, and the track becomes abnormally worn. For this purpose, the operator depresses the dexel pedal to reduce the engine output and reduce the traction force to prevent crawler track slippage, but this makes the operator's operations cumbersome.

In addition, traveling faster when traveling backwards can shorten the cycle time during forward dosing work and improve efficiency, but since the engine output characteristics are set to match the forward dosing work, when traveling backwards The speed cannot be increased very much.

Bulldozers are used in a variety of ways, but the engine output characteristics are set to match the work of advancing dozing, so when doing work other than advancing dozing, the engine output is This means that the fuel cannot be used effectively and without wasting fuel.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for controlling engine output characteristics of a bulldozer, which allows the engine output characteristics to be freely set in accordance with the work.

[Means and effects for solving the problem] The output torque curve suitable for each work of the bulldozer is set in advance as a mode, and the engine output is controlled according to the selected output torque curve, so that each work This allows the engine output to be used effectively.

[Example] As shown in Fig. 2, a bulldozer has a blade 2 on a vehicle body 1.
At the same time, the output side of the engine 4 is connected to a sprocket 5 via a power line (not shown), and the crawler belt 6 is driven by the sprocket 5.

As shown in FIG. 1, the engine 4 is supplied with fuel and its output is controlled by a fuel injection pump 8 equipped with an electronically controlled governor 7.
The control rack 9 is made reciprocating by a cylinder 10, and pressure oil from a hydraulic source 11 is supplied to the pressure chamber 10a of the cylinder 10 by a control valve 12, and a differential transformer is used to detect the position of the controller rack 9. The engine controller 15 outputs a control signal to the control valve 12 in accordance with the amount of operation of the main control lever 14 to supply pressure oil to the pressure chamber 10a of the cylinder 10 and cause the control rack 9 to reciprocate. When the engine moves, its position is detected by the sensor 13 and fed back to the engine controller 15 so that the position corresponds to the input operation amount.

The engine controller 15 includes an engine output characteristic storage section 16 in which a plurality of engine output characteristics, that is, engine output torque curves, are stored. One engine output characteristic is read out, and a control operation is performed in accordance with the amount of operation of the main control lever 14 so as to obtain that engine output characteristic.

For example, as shown in Fig. 3, the high output torque curve A1 suitable for dozing forward work is
, third small output torque curves B, C, and D, and high rotational output torque curve E suitable for backward running work are stored, and the selection switch 17 is set to standard position I, first, second, and third ripping positions n, m, (2) The engine controller 15 selects one of the engine output curves from the engine output characteristic storage section 16 using the selection signal from the selection switch 17 and the speed signal from the transmission controller 18. Read out.

That is, read out as shown in the table below.

On the other hand, as shown in Fig. 4, the traction force at the high output torque curve A is fA in the first forward speed and r^ in the second reverse speed, and the traction force at the high output torque curve A is fA in the first forward speed and r^ in the second reverse speed. The traction force when in D is f9. in 1st forward speed. fc and fD, and the traction force at high speed rotation output torque curve E becomes "E" in second reverse gear.

Because of this, when performing ripping work at forward l speed, the vehicle speed is slower than when doing forward dozing work, and track slippage can be prevented without the need to reduce engine output using the dexel pedal. Since the rate of change in traction force due to changes in (vehicle speed) can be reduced, fine controllability using the dexel pedal can be improved, and since it can be switched to three stages, it is possible to adjust to the hardness of the rock and perform pipping work.

Furthermore, when the vehicle is steered backward in the second reverse speed, the engine rotation speed becomes higher than when the vehicle is in forward dossing work, and the vehicle speed becomes faster, thereby shortening the cycle time of dossing work and improving efficiency. The same applies when traveling backwards in the first reverse speed.

In addition, the engine output torque curve is on the side.

It is set to be suitable for cutting work, land leveling work, and soft rock dozing work, and is selected when carrying out that work.

It may be possible to switch to that engine output torque curve with a switch.

〔Effect of the invention〕

You can freely set the enmo output to a value suitable for the work of the bulldozer, and you can use the engine output effectively without wasting it.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an example of an apparatus for carrying out the method according to the present invention, and FIG. 2 is an outline of a bulldozer. The front view, FIG. 3 is a chart of engine output characteristics, and FIG. 4 is a chart of traction force.

Claims (1)

[Claims] The engine output is controlled along the high output torque curve that provides high output during normal dozing work, and
A method for controlling engine output of a bulldozer, characterized in that when carrying out operations other than the normal dozing work, the engine output is controlled along a preset output torque curve suitable for each operation.