JPS6319343A - Shoe-slip controller - Google Patents

Abstract

PURPOSE:To cut down the repairing cost of the step portion of an earthwork machine by a method in which, when the load of the earthwork is increased, the occurrence of shoe-slip is detected, and the load of the earthwork is reduced through a servo-actuator to control the occurrence of shoe-slip. CONSTITUTION:A torque converter output rotation speed and engine rotation speed are detected by a torque converter output rotation meter 1 and an engine rotation meter 2, and changing rate (e) for a time to a torque converter speed ratio is calculated in a controller 3. When the value is greater than a preset value e0, a command to raise a blade or lipper is sent out to a servo actuator 4 from the controller 3. A direction switch valve 5 is switched by the actuator 4, and a lift cylinder 6 is raised to reduce loads on an earthwork machine. The operation of the earthwork machine can thus be mostly automatized and the repairing cost of step portion can be reduced.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a device for controlling the slippage of the shoes of a track-type construction vehicle, and particularly to a bulldozer with a torque converter transmission that performs uplifting work and lymphatic work. It is suitable for use.

(Prior technology) Conventionally, there was a technology to measure shoe slip by measuring the ground speed of the vehicle body using the Doppler effect, but there was no technology to cumulatively control shoe slip.
The operator's cumin reduces the load on the construction vehicle's work equipment and reduces the time during which shoe slips occur.

(Problem to be solved by the invention) In the above conventional track type construction vehicle.

There are many parts around the undercarriage that wear out due to contact with earth and sand, and especially in bulldozers that perform uplifting and lymphatic work, the wear is accelerated by shoe slips, and shoe slips can be prevented by the operator's own effort. There are limits to efforts to reduce costs, and as a result, undercarriage repair costs currently account for the majority of bulldozer repair costs.

(Means and operations for solving the problems) The present invention was made in view of the above points, and it is possible to measure the torque converter turbine rotational speed Nt from the output tachometer of a torque converter (hereinafter abbreviated as a torque converter). A signal of -17 pump rotational speed Np from the No. 4λ, edge, and tachometer is input to the controller, and the rate of change 6 of the torque converter speed ratio e (=Nt/Np) with respect to time is calculated by the controller.

This rate of change δ is a preset value δ. When the shoes become thicker, the controller determines that a large shoe slip condition has occurred, issues a command to the servo actuator, and the servo actuator switches the directional control valve to raise the work equipment lift cylinder. This load is reduced and the occurrence of large shoe slips is suppressed.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a flowchart explaining the invention in detail, and FIG. 2 is a detailed illustration of the invention. 1 and 2, the torque converter output rotation speed Nt (-torque converter turbine rotation speed) and the engine rotation speed Np
The torque converter output tachometer 1 and the engine tachometer 2 detect the torque converter output tachometer 1 and the engine tachometer 2, respectively, and the controller 3 detects the torque converter speed ratio e(=
Calculate the rate of change δ of Nt/Np) with respect to time, and calculate this δ
is thicker than the preset value a0 (when it becomes so, it is determined that the crawler track is spinning around and a large shoe slip is occurring.

The controller 3 issues a command to the servo actuator 4 to raise the blade or buckwheat, and the servo actuator 4 operates and switches the directional control valve 5, so that the time T2 (blade or ripper) becomes equal to the set 8. Namely.

When carrying out earthwork work while a track-type construction vehicle is running, there is always shoe slip corresponding to the load of one work machine), and the controller 3 issues a command to the servo actuator 4, sets the directional control valve 5 to the neutral position, and stops the blade or ripper from rising.

FIGS. 3 and 4 show another embodiment of the invention,
The embodiment shown in FIG. 4 has a vehicle running accelerometer 11 added to the embodiment shown in FIG. 2, and other same devices are given the same reference numerals as in FIG. 2. FIG. 3 is a flowchart explaining the operation of the system shown in FIG. 4, and the differences from the system shown in FIG. 1 are as follows. At

dt (that is, the vehicle is decelerating), and the rate of change e of the torque converter speed ratio with respect to time is a preset value 6. When it becomes larger, it is determined that a large shoe slip 7 has occurred.

FIG. 5 and FIG. 6 show still another embodiment of the present invention, in which a track-type construction vehicle shifts from, for example, forward first speed (hereinafter abbreviated as F1) to forward second speed (hereinafter abbreviated as F2) during earthwork work. The vehicle then stops for a moment and then picks up speed again, but if the vehicle speed is slow to recover, the amount of work will decrease, so it may be possible to temporarily increase engine output when shifting gears to improve acceleration. However, instead of temporarily increasing the engine output, what was explained in FIGS. 1 and 2 above is applied. That is, the embodiment shown in FIG. 6 has a transmission speed change detector 21 added to the embodiment shown in FIG. 2, and other same devices are given the same reference numerals as in FIG. 2. FIG. 5 is a flowchart explaining the operation of the one shown in FIG. 6, and the differences from the one shown in FIG. 1 are as follows. That is, when the transmission speed change detector 21 detects that the speed has changed.

During the transition from Fl to F2, the instantaneous torque converter gear ratio e is thick (
However, after shifting to F2, the torque converter gear ratio e decreases rapidly, so when the preset value of the shift weight for the time of the torque converter gear ratio e becomes smaller than 2, the vehicle speed approaches 0. The system determines that this is the case and raises the earthmoving machine cylinder to reduce the earthmoving machine load.

(Effect of the invention) This invention is constructed as described above in detail.

In other words, when a bulldozer that performs uplifting and lymphatic work is doing earthwork work, when the load on the earthmoving machine becomes large and a large shoe slip is about to occur, it detects this and automatically reduces the load on the earthmoving machine and eliminates the large shoe slip. By suppressing the occurrence of this, most of the earth-moving machine operation operations, which were previously left to the operator, are performed automatically, reducing operator fatigue and reducing the need for operating skills. Furthermore, it has the great effect of significantly reducing the cost of repairing the undercarriage, which used to account for most of the cost of repairing the bulldozer.

Also, when a tracked construction vehicle is moving and doing earthwork work, when the gear is changed, the vehicle stops momentarily.

When the speed increases again but there is a problem that the amount of work decreases if the recovery of the vehicle speed is slow, the present invention can be applied to eliminate such problems.

[Brief explanation of drawings]

FIG. 1 is a flowchart explaining the operation of a shoe slip control device according to an embodiment of the present invention. FIG. FIG. 4 is a flowchart for explaining the main part of the process shown in FIG. 3, FIG. 5 is a flowchart for explaining the operation of yet another embodiment, and FIG. It is a diagram. 1...Torque converter output tachometer. 2...Engine revolution meter, 3...Controller. 4... Servo actuator. 5... side, open switching valve, 6... lift cylinder. 11...Vehicle running accelerometer. 12...Transmission speed change detector. Patent Applicant: Komatsu Ltd. Representative (Patent Attorney) Tomo Matsuzawa 2 Figure 4 Ina 69

Claims (1)

[Claims] In a tracked construction vehicle, there is an engine tachometer and a torque converter output tachometer that detect the input and output shaft rotation speed of the torque converter, a controller that issues a command when a large shoe slip occurs, and a controller that issues a command when a large shoe slip occurs. It is characterized by comprising a directional control valve and a servo actuator that raises the work equipment lift cylinder.
Shoe slip control device.