1、_SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising theref
2、rom, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions.Copyright 2012 SAE International All rights reserved. No part of this pub
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4、(outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/J1098_201203SURFACEVEHICLESTANDARDJ1098 MAR2012 Issued 1975-11 Revised 2012-03Supers
5、eding J1098 MAY1995 Tonne Kilometer Per Hour Application RATIONALEDocument SAE J1098 “Tonne Kilometer Per Hour Application” covers time tested procedures and applications. As such the methodology continues to be acceptable in its present form. Therefore, the document is being revised with no signifi
6、cant technical changes. 1. SCOPE This SAE Standard establishes the procedures for the application of Tonne Kilometer Per Hour (TKPH) rating values for off-the-road tires; utilizing empirical data formula, it describes the procedure for evaluating and predicting off-the-road tireTKPH requirements as
7、determined by a work cycle analysis.1.1 The loads, speeds, inflations, and rim configurations are assumed to be within acceptable industry or manufacturers prescribed recommendations. 1.2 Other application parameters affecting tires are not included in the scope (for example: flotation, cut, bruise,
8、 wear, etc.). These parameters must also be considered for final tire selection, since a tire that maximizes desirable TKPH characteristics will sometimes compromise these other parameters. 1.3 The standards for the productivity of off-the-road machines or tires are not included in the scope. 1.4 Th
9、e formulae (4.2 and 4.3) are applicable to transport type machines only (that is, trucks, tractor trailers, and scrapers) using Category E Earthmover Service Code Tires. See SAE J751 for service codes. 2. REFERENCES 2.1 Applicable Documents The following publications form a part of this specificatio
10、n to the extent specified herein. Unless otherwise indicated, the latest issue of SAE publications shall apply. SAE J1098 Revised MAR2012 Page 2 of 5 2.1.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada)
11、or 724-776-4970 (outside USA), www.sae.org.SAE J751 Off-Road Tire and Rim ClassificationConstruction Machines SAE J1015 Tonne Kilometer Per Hour Test Procedure SAE J1116 Categories of Off-Road Self-Propelled Work Machines 3. GENERAL (INTRODUCTION TO TKPH) A tire operated at its SAE J1015 TKPH rating
12、 will achieve a stabilized temperature under continuous operation without heat damage. 3.1 Origin of Tire Heat The temperature described in Section 3 occurs at or near the interface of the undertread and carcass (see SAE J751, Figure 1). This results from the transitory load on the tire crown causin
13、g the tire to flex, producing the greatest stresses ator near the junction of the undertread and carcass. The TKPH rating of a tire is established from the maximum stabilized temperature, which the tire can sustain along that interface. 3.2 Effect of Tire Heat As a tires temperature increases, its m
14、aterial strengths decrease (Figure 1). Repeated or sustained exposure to excessive temperatures will ultimately produce tire damage. Heat damage is progressive; it may go undetected or become evident under operating conditions where no apparent cause exists.FIGURE 1 - TEMPERATURE EFFECTS 3.3 Effect
15、of Load and Inflation Tire deflection is a function of its load and inflation pressure. When a tire is operated above its normal deflection range due to insufficient inflation pressure relative to the load carried (see 1.2), excessive heat build-up may take place in the tire. This will affect the ti
16、res TKPH capabilities. SAE J1098 Revised MAR2012 Page 3 of 5 3.4 Work Cycle Influence on Tire Temperature A tire performing within acceptable deflection limits will generally attain an equilibrium temperature. Various combinations of empty and loaded machine hauls may be programmed to produce accept
17、able tire temperatures. However, if any operating parameter is altered so as to exceed the tires TKPH rating, tire heat damage can result. Some examples are: a. Increase in operating cycle speed. (Consider individual driver practices.) b. Increase in machine loading due to change in material density
18、 and/or machine modification. c. Adverse weight distribution due to loading techniques or haul road grade. 3.5 Job Site Condition Influence on Tire Temperature Other items not directly affecting the TKPH calculations, but increasing tire temperature are: a. Shift schedule increase where equilibrium
19、temperatures had not previously been attained. b. Ambient temperature in excess of 38 C. c. Adverse road conditions (crown, curves, surface, etc.). d. Excessive brake heat. e. Vehicle configurations which limit tire cooling. f. Excessive heat from machine exhaust system. 4. DETERMINING THE TKPH JOB
20、RATE This section defines the formula with limitations for calculating the Tonne Kilometer Per Hour job rate of an individual tire based on work cycle analysis. For the working formula (4.3), the tire with the highest average load must be considered. 4.1 Nomenclature H = time, hours, total for the d
21、ay from the beginning of the first shift to the end of the last shift J = job rate in TKPH K = length of round trip, kilometers KL= length of loaded haul, kilometers KE= length of empty haul, kilometers N = the number of round trips for the time (H) period NE= the number of empty trips for the time
22、(H) period NL= the number of loaded trips for the time (H) period R = tire rating in TKPH as determined by SAE J1015 TL= tire load, metric Tonnes, on the loaded machine TE= tire load, metric Tonnes, on the empty machine TTLTE+2- for the tire with the highest average load in metric tons()=(Eq. 1) Ton
23、ne = 1000 kg SAE J1098 Revised MAR2012 Page 4 of 5 4.2 General Formula The general formula is shown in Equation 2: H2NKTNKTJEEELLL+= (Eq. 2) (Refer to 4.1 for Nomenclature.) Heat generation and retention in a tire is not simply a linear function of the Tonne Kilometer Energy Rate. (Refer to 3.1, 3.2
24、, 3.3, 3.4, and 3.5.) Hence, this formula is usable only within certain limitations as defined in 4.4. 4.3 Working Formula Equation 3 should be used with limitations in 4.4. )Hours(TimeTraveledKilometersTonnesinLoad.AvgHighestJ = (Eq. 3) JTKH-=(Eq. 4) 4.4 Limitations Application limitations vary fro
25、m one tire manufacturer to another. Individual tire manufacturers should be consulted for deviations from the following general limitations. 4.4.1 Load For loads per tire, refer to current Tire and Rim Association Yearbook 50 km/h Table, the tire manufacturers 50 km/h publication, or his specific ap
26、plication approval. 4.4.2 Distance Empty and loaded hauls should be equal distance. Consult tire manufacturer on distance. 4.4.3 Number of Round Trips If they are not relatively uniform throughout the work day, the maximum round trips per hour shall be used to calculate TKPH job rating. 4.4.4 Ambien
27、t Temperature Consult tire manufacturer for correction formula for ambient temperatures less than or greater than 38 C. TKPH is normalized to 38 C. 4.5 Evaluating the Calculated Value If the Job Rate (J) is equal to or less than the Tire Rating (R), then heat damage should not occur (that is, J R).
28、If the Job Rate (J) is greater than the Tire Rating (R) (that is, J R), then the job cycle and/or tire must be changed to meet the conditions of J R.SAE J1098 Revised MAR2012 Page 5 of 5 4.5.1 Excessive TKPH Remedies a. Reduce T (load) b. Reduce average speed. Increase delays or reduce N (No. of rou
29、nd trips for time period). c. Reduce K (round trip length) by locating the haul road to a more direct route. d. Equip the machine(s) with tires of higher R (TKPH rating). 5. FIELD EVALUATION When calculated job rates indicate critical TKPH tire temperatures will prevail, a tire temperature study sho
30、uld be made on the job site following the procedure outlined in 4.3 and Section 5 of SAE J1015. 6. JOB ANALYSIS On operations where premature tire removals due to heat separation occur, although TKPH calculations indicate an acceptable job rate, factors contributing to heat damage (see 3.4 and 3.5)
31、must be isolated and corrected. 7. NOTES 7.1 Marginal Indicia A change bar (I) located in the left margin is for the convenience of the user in locating areas where technical revisions, not editorial changes, have been made to the previous issue of this document. An (R) symbol to the left of the document title indicates a complete revision of the document, including technical revisions. Change bars and (R) are not used in original publications, nor in documents that contain editorial changes only. PREPARED BY THE SAE MTC8, TIRE AND RIM COMMITTEE OF THE MACHINE TECHNICALSTEERING COMMITTEE
