Method for advocating particular tires for use and for calculating on site inflation pressures of said tires for a construction vehicle

• US 7,049,949 B2
• Filed: 09/13/2004
• Issued: 05/23/2006
• Est. Priority Date: 03/13/2002
• Status: Expired due to Term

• Current Assignee: Compagnie générale des établissements Michelin
• Original Assignee: Michelin Recherche et Technique SA (Compagnie Generale DES Etablissements Michelin SCA)
• Inventors: Champeau, Christian
• Primary Examiner(s): Jules, Frantz F.
• Application Number:
  US10/938,785
• Publication Number:
  US 20050080777A1
• Time in Patent Office: 617 Days
• Field of Search: 707/3, 707/104.1, 707/4, 707/5, 340/442, 340/443, 731/463, 731/465, 731/46, 701/50, 701/29
• US Class Current: 340/442
• CPC Class Codes: B60C 23/00 Devices for measuring, signalling, controlling, or distributing tyre pressure or temperature, specially adapted for mounting on vehicles; Arrangement of tyre inflating devices on vehicles, e.g. of pumps or of tanks; Tyre cooling arrangements
• CPC Class Codes: B60C 23/002 by monitoring conditions other than tyre pressure or deformation

Abstract

A method and a system for advocating tires and for calculating on site inflation pressures of the said tires for a so-called construction vehicle, in which, using data on the vehicles, the tires and the conditions of use, an estimate of the load on the bucket of the construction vehicle is calculated and the appropriate type of tires and inflation pressures therefore are chosen.

Claims

1. A method of advocating tires on a worksite and calculating on the worksite the inflation pressures of said tires for a construction vehicle having a front axle, a rear axle and a bucket intended to receive a load of material having a density DM, comprising the steps of:

A) making an estimate of a filling level TR of the bucket in conditions of maximum load for use on the worksite;

B) calculating a load CG created by the material filled to the filling level TR in the bucket from the bucket capacity VG and the estimated values for density DM and filling level TR;

C) calculating an overload V on the front axle from a tipping load CB which would produce a tipping of said vehicle;

D) verifying the value obtained for the overload V on the front axle from observations made when the vehicle is loaded to its maximum load for use on the worksite and when empty;

E) if the result of the verification of step D is negative, correcting the estimates of the density DM and/or the filling level TR and performing again the verification of the value obtained for the overload V on the front axle;

F) if the result of the verification of step D is positive, validating the estimate of the maximum load on the bucket CG in the conditions of use on the worksite;

G) using the value for the maximum load CG to calculate total loads ZAV and ZAR on the front axle and the rear axle, respectively;

H) calculating the load on each front tire by dividing by two the total load ZAV on the front axle calculated in step G, and choosing a load value for each tire of the rear axle greater than the total load ZAR on the rear axle divided by two;

I) determining the conditions of the terrain on the worksite and the average speed of use of the vehicle;

J) making a search of data from tire manufacturers for the type or types of tires and characteristics of tires, including type, tread pattern and rubber compound quality, which most closely correspond to the loads calculated for the tires of the front axle and the rear axle, for the conditions of use of the vehicle on the worksite, including the conditions of the terrain, and the average speed of use;

K) making a search of data from tire manufacturers for the operating pressures of the tires selected in step J on the front axle and rear axle respectively, corresponding to the loads calculated for the tires of the front axle and rear axle in step H; and

L) choosing the operating pressures and the tires for said vehicle.

2. A method according to claim 1 wherein the verifying of the overload V on the front axle in steps D and E comprises measuring the sagging of at least one of the tires of the vehicle, between the sag value with no load and the sag value when the tire in question is loaded.

3. A method according to claim 1 wherein the load CG is calculated in step B from the equation

$\mathrm{CG}=\mathrm{VG}\times$

DM ×

TR 100

and the overload V is calculated in step C from the equation

$\mathrm{CG}=\frac{V}{100}\times <br><br>\mathrm{CB}$

where CG=bucket load

VG=capacity of the bucket in m³,

DM=density of the material to be loaded in kg/m³,

TR=level of filling of the bucket in %,

V=estimate of the overload on the front axle resulting from the load on the bucket, expressed as % of the tipping load of the vehicle, and

CB=tipping load of the vehicle in kg.

4. A method according to claim 1 wherein the total loads ZAV and ZAR are calculated in step G from the equations:

$\mathrm{ZAV}=\mathrm{VAV}+\left(\frac{\mathrm{CB}+\mathrm{VAR}}{\mathrm{CB}}\right)\times <br><br>\mathrm{CG}$ $\mathrm{ZAR}=\mathrm{VAR}-\left(\frac{\mathrm{VAR}}{\mathrm{CB}}\right)\times <br><br>\mathrm{CG}$

where ZAV=load on the front axle;

ZAR=load on the rear axle;

VAV=load on the front axle when empty;

VAR=load on the rear axle when empty;

CG=bucket load;

CB=tipping load of the vehicle in kg.

5. A method according to claim 1 wherein the average speed is determined in step I from the equation

speed=L×

Nb

where;

L=length of the cycle for loading/unloading in km;

Nb=number of cycles per hour.

6. A method of advocating tires on a worksite and calculating on the worksite the inflation pressures of said tires for a construction vehicle having a front axle, a rear axle and a bucket intended to receive a load of material having a density DM, comprising the following steps:

A) making an estimate of an overload V on the front axle in conditions of maximum use of the bucket from observations made when the vehicle is at maximum load for use on the worksite and when empty;

B) calculating and displaying a load CG in the bucket from a tipping load CB which would produce a tipping of the vehicle, from the equation;

$\mathrm{CG}=\frac{V}{100}\times <br><br>\mathrm{CB}$

C) calculating a filling level TR of the bucket under said conditions of maximum load for use from the capacity VG of the bucket of said vehicle and estimating the values above DM and V from the equation;

$\mathrm{TR}=\frac{\mathrm{CG}}{\mathrm{VG}\times <br><br>\mathrm{DM}}\times <br><br>100$

D) verifying the value obtained for the filling level TR of the bucket from observations made when the vehicle is loaded to its maximum load for use on the worksite;

E) if the result of the verification of step D is negative, correcting the estimates of the density DM and/or the overload V on the front axle and performing again the verification of the value obtained for the filling level TR of the bucket;

F) if the result of the verification of step D is positive, validating the estimate of the maximum load CG on the bucket in the conditions of use on the worksite;

G) using the value for the maximum load CG on the bucket validated in step F, to calculate total loads ZAV and ZAR on the front axle and the rear axle, respectively, from the equations

$\mathrm{ZAV}=\mathrm{VAV}+\left(\frac{\mathrm{CB}+\mathrm{VAR}}{\mathrm{CB}}\right)\times <br><br>\mathrm{CG}$ $\mathrm{ZAR}=\mathrm{VAR}-\left(\frac{\mathrm{VAR}}{\mathrm{CB}}\right)\times <br><br>\mathrm{CG}$

where ZAV=load on the front axle,

ZAR=load on the rear axle,

VAV=load on the front axle when empty,

VAR=load on the rear axle when empty

H) calculating the load on each front tire by dividing by two the total load ZAV on the front axle calculated in step G, and choosing a load value for each tire of the rear axle greater than the total load ZAR on the rear axle divided by two;

I) determining the conditions of the terrain on the worksite and the average speed of use of the vehicle;

J) making a search of data from tire manufacturers for the type or types of tires and characteristics of tires, including type, tread pattern and the rubber compound quality, which best correspond to the loads calculated for the tires of the front axle and the rear axle, for the conditions of use of the vehicle on the worksite, including the conditions of the terrain, and the average speed of use;

K) making a search of data from tire manufacturers for the operating pressures of the tires selected in step J on the front axle and rear axle respectively, corresponding to the loads calculated for the tires of the front axle and rear axle in step H; and

L) choosing the operating pressures and the tires for said vehicle.

7. A method according to claim 6 wherein the estimating and/or verifying of the overload V on the front axle in steps D and E comprises measuring the sagging of at least one of the tires of the vehicle, between the sag value with no load and the sag value when the tire in question is loaded.

8. A method according to claim 6 wherein the load CG is calculated in step B from the equation

CG=VG×

DM×

CB

and the overload V is calculated in step A from the equation

$\mathrm{CG}=\frac{V}{100}\times <br><br>\frac{\mathrm{TR}}{100}$

where CG=bucket load

VG=capacity of the bucket m³,

DM=density of the material to be loaded in kg/m³,

TR=level of filling of the bucket in %,

V=estimate of the overload on the front axle resulting from the load on the bucket, expressed as % of the tipping load of the vehicle, and

CB=tipping load of the vehicle in kg.

9. A method according to claim 6 wherein the total loads ZAV and ZAR are calculated in step G from the equations:

$\mathrm{ZAV}=\mathrm{VAV}+\left(\frac{\mathrm{CB}+\mathrm{VAR}}{\mathrm{CB}}\right)\times <br><br>\mathrm{CG}$ $\mathrm{ZAR}=\mathrm{VAR}-\left(\frac{\mathrm{VAR}}{\mathrm{CB}}\right)\times <br><br>\mathrm{CG}$

where ZAV=load on the front axle;

ZAR=load on the rear axle;

VAV=load on the front axle when empty;

VAR=load on the rear axle when empty;

CG=bucket load;

CB=tipping load of the vehicle in kg.

10. A method according to claim 6 wherein the average speed is determined in step I from the equation

speed=L×

Nb

where;

L=length of the cycle for loading/unloading in km;

Nb=number of cycles per hour.