SU1239231A1 - Method of determining the degree of filling of loader bucket - Google Patents

Description

The invention relates to loading and transport equipment, in particular, to methods for automatically controlling the filling of a loader bucket with remote control out of direct view of the loading body.

The purpose of the invention is to increase efficiency by reducing the time and simplifying the measurement process with remote control.

FIG. 1 shows a functional diagram of an apparatus for implementing the method; in fig. 2 is a graph of experimental dependence of boom down time on loading.

The device comprises an arrow 1 with a hydraulic cylinder 2 for lifting the boom, to the rod and piston cavity of which, through the distributor 3, a pressure head 4 and a drain 5 of the main are connected. The distributor 3 has four positions: I - “Lifting (the pneumatic cavity is connected to the pressure one, and the rod - to the drain main), P -“ Lowering (the pneumatic cavity is connected to the drain, shtokov - from the pressure main), III - “Neutral ( both cavities are disconnected from the main lines), IV - “Weighing (both cavities are connected to each other and to the drain line). The distributor 3 is equipped with a position monitoring sensor 6 "Weighing, the output of which is connected to one of the inputs of the matching circuit 7, to the other input of which the sensor 8 of the upper boom position is connected. Vertically, at a given distance h from sensor 8, sensor 9 of the lower boom position is located. The outputs of the circuit 7 and the sensor 9 are connected to the inputs of the remote switch 10, the corresponding outputs of which are connected to the on and off circuits of the timer 11. The remote switch 10 is in one of two steady states when the voltage is applied to the corresponding input. Thus, timer 11 is turned on at the time of the occurrence of voltage at the output of circuit 7 and is turned off after sensor 9 triggers. The output of timer 11 is connected to the load indicator 12.

The method is based on experimental and analytical studies that showed that the time for free lowering of the loader boom linearly depends on the weight of the loading body and, when fully loaded, the bucket decreases by 1 -1.8 s.

From the free piston lowering equation in the hydraulic cylinder

, dV „„.,

mjj- mg

l 4g

derived formula for the time of lowering the working body

, m / kVEi) 3Arch (lllK);

TO

m

 - fVrg

where w is the mass of the working body with a ladle, 5 is brought to the hydraulic cylinder rod;

tnp

- piston friction force;

h is the distance of the boom movement; g is the acceleration of free fall;

I is the coefficient of local resistance;

„And fo- areas of the piston and the throttling hole.

For a specific loader, the K values

and tr is constant, b is given by constant,

therefore, the lowering time t depends only

by weight m of the working body, moreover

as the factor m increases, the Arch factor ({-) decreases faster than the factor multiplies, which leads to an almost linear decrease in the time of descent. The loading of the P bucket can be determined from the expression

t - to

where a is a constant coefficient depending on Fmp, h, I, fn, fo (determined by

„Experimentally or analytically for each type of loader), kN-s;

to - time to lower the boom with empty

for a given distance, c.

According to experimental dependencies

the boom lowering time from loading for PD-8M (a) and TOPO-350D (b) loaders is determined by the proportionality coefficients for PD-8M - 96 kNs, for TORO-350D 104 kN s.

The method is implemented as follows.

After the loading is complete, the distributor 3 is switched to position I "Lifting, connecting the piston cavity of the hydraulic cylinder to the pressure line 4, and raising the boom to an arbitrary height exceeding the installation height of the sensor 8. During the lifting process, sensors 8 and 9 operate, but timer 11 remains off, since the voltage at the output of the sensor 6 and, therefore, the circuit 7 is missing.

0 Then, the distributor 3 is moved to position IV "Weighing, connecting the two cavities of the hydraulic cylinder 2 to the drain line 5. This triggers the sensor 6 and the boom is lowered under its own weight. In the process of lowering, sensor 8 triggers, a voltage appears at the output of circuit 7, and remote switch 10 turns on timer 11. Sensor 9 then triggers, causing a transition

the switch 10 is switched to another state and the timer 11 is turned off. Thus, the indication of the load indicator 12 corresponds to the free fall time of the boom, depending on the load level of the bucket.

Verification of the proposed method was carried out on bucket loading and transport machines PD-8M and TOPO-350D. As a timer, a rectangular pulse generator was used, which is connected to the pulse counter via the closing relay contacts, the winding of which is connected

on to the output of the contactless track switch of the BVK series, mounted on the frame of the machine. The displacement h of the boom was specified in the form of the width of the switching stop associated with the boom with the possibility of displacement in the clearance of the path switch. The results showed that when the bucket was loaded with a reference load from 0 to 80 kN, the time of free lowering of the boom to a height of 20 cm linearly decreased from 2.0 to 0.8 s (PD-8M) and from 1.6 to 0.3 s (TOPO - 350D).

2.0

1.0

ABOUT

25

75

- P, k //

Claims (1)

METHOD FOR DETERMINING THE LOADING DEGREE OF THE LOADER'S BUCKET, including boom lifting at the end of loading, characterized in that, in order to increase efficiency by reducing time and simplifying the measurement process with remote control, the boom travel distance is set by setting the boom top and bottom sensors at the extreme points, raise the boom to a height exceeding the height of the upper sensor, at the end of boom lifting, the boom is freely lowered by connecting both cavities ilindra boom with the drain line, measure the time of passage an arrow a predetermined distance and the degree of loading of the bucket is determined inversely proportional to the measured time linearly. SU .. „1239231