JPH02147919A - Overload detection device for dump trucks for construction machinery - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for detecting overload applied to the frame of a dump truck for construction machinery.

[Conventional technology]

A dump truck for construction machinery has a body attached to a frame so that it can move up and down, loads earth and sand into the body, travels to a dump site, and then stands up to discharge the earth and sand.

[Problem to be solved by the invention]

Dump trucks for construction machinery have a heavy load of several tens of tons of earth and sand loaded into their bodies, and because they drive over rough, uneven terrain, a large load acts on the frame.
Driving at high speeds on rough, uneven terrain increases the vertical vibration of the vehicle body, causing an overload that exceeds the allowable load on the frame and causing early damage.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an overload detection device for a dump truck for construction machinery that allows an operator to detect when an overload is applied to a frame.

[Means and operations for solving the problem] A pressure sensor that detects the pressure in the extension oil chamber of each suspension cylinder;
This is an overload detection device equipped with a CPU that calculates the stress in each part of the frame based on each detected pressure and activates a warning device when the stress exceeds the allowable stress.This allows the operator to detect when an overload has been applied to the frame. .

〔Example〕

As shown in FIG. 2, when a front wheel 2 and a rear wheel 3 are attached to a vehicle body 1, a driver's cab 4 and a body 5 are provided to constitute a dump truck for construction machinery, and the front wheels 2 are attached to a vehicle body 1 as shown in FIG. It is attached to the vehicle body 1 with a link 6 so as to be able to swing vertically, and a front suspension cylinder 7 is connected across the front wheel 2 and the vehicle body 1.The rear wheel 3 is provided on an axle 8, and the axle 8 is It is attached to the vehicle body 1 by a pair of links 9 so as to be able to swing vertically, and a pair of left and right rear suspension cylinders 10 are connected between the axle 8 and the vehicle body 1.

As shown in FIG. 4, in each of the suspension cylinders, a piston 13 having a piston rod 12 is inserted into a cylinder tube 11 to form an extension oil chamber 14 into a contraction oil chamber 15, and both sleeve chambers are formed with small holes. At the same time, N2 gas 16 is sealed in the upper part of the extension oil chamber 14, and the pressure sensor 17
The pressure inside the extension oil chamber 14 is detected at this point.

The detection signals of the pressure sensors 17 of each suspension cylinder are input to the CPU 20 via the A/D converter 18 and the interface 19 as shown in FIG. At the same time, the position of the center of gravity of the load is calculated, and the load acting on each part of the frame is calculated based on the total load and the position of the center of gravity.

FE with preset loads acting on each part of this frame
The stress in each part of the frame is calculated by inputting it to the M model, and the stress is compared with the allowable stress. If the stress is greater than the allowable stress, a signal is sent to the driver's cab 4 via the interface 21 and the amplifier 22.
The signal is output to a warning device provided at the terminal, for example, a warning lamp 23, and the warning lamp 23 is activated.

In FIG. 1, 24 is a RAM, 25 is a ROM 126 is a clock pulse generator, and 27 is a timer.

The above operation is shown in a flowchart as shown in FIG.

〔Effect of the invention〕

The pressure in the extension oil chamber 14 of each suspension cylinder varies depending on the loaded weight and the position of the center of gravity of the loaded object, as well as due to the impact caused when driving on uneven, uneven ground. The pressure in the room is detected by a pressure sensor, and the detected pressure is used to calculate the stress acting on each part of the frame, and a warning device is activated when the stress exceeds the allowable stress.This allows the operator to notify the operator that an overload has been applied to the frame. can be detected, thereby making it possible to reduce overload by slowing down the running speed, thereby preventing frame damage.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a circuit diagram, Fig. 2 is a front view of a dump truck for construction machinery, Fig. 3 is a perspective view of the front and rear wheels attached, and Fig. 4 is a cross section of a suspension cylinder. FIG. 5 is a flowchart.

Claims (1)

[Claims] In a dump truck for construction machinery, in which a front wheel 2 is mounted on a frame 4 through a front suspension cylinder 7, a rear wheel 3 is mounted on a rear suspension cylinder 10, and a driver's cab 4 and a body 5 are provided on the frame 1, each suspension A pressure sensor 17 detects the pressure in the extension oil chamber 14 of the cylinder, and calculates the stress acting on each part of the frame based on the detected pressure of each pressure sensor 17, and sends a signal when the stress is greater than the allowable stress. CPU20 to output,
An overload detection device for a dump truck for construction machinery, characterized by being provided with a warning device activated by a signal from a CPU 20.