IS 11948 : 1999 UAT AE waa aed — Reaftt yart — yeast wala ( Teer Freer ) Indian Standard AUTOMOTIVE VEHICLES — STEERING EFFORT — METHOD OF EVALUATION ( First Revision ) ICS 43,040.50; 19,060 OBIS 1999 BUREAU OF INDIAN STANDARDS MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG NEW DELHI 110002 February 1999 Price Group 2Automotive Vehicle Testing and Performance Evaluation Sectional Committee, TED 8 FOREWORD This Indian Standard (First Revision) was adopted by the Bureau of Indian Standards, after the draft finalized by the Automotive Vehicle Testing and Performance Evaluation Sectional Committee had been approved by the Transport Engineering Division Council. The overall performance of an automotive vehicle is a function of performance of its various components, systems, instrumentation, etc. Assessment of steering effort is an important parameter in the performance of an automotive vehicle. This revision has been undertaken to update the contents of the standard in accordance with the following: EC Directive No, 92/62 ECC Regulation No. 79.01 The composition of the committee responsible for preparation of this standard is given in Annex B.IS 11948 : 1999 Indian Standard AUTOMOTIVE VEHICLES — STEERING EFFORT — METHOD OF EVALUATION ( First Revision ) 1 SCOPE This standard outlines the method of evaluation of steering effort of all automotive vehicles fitted with steering wheel. 2. REFERENCES ‘The following Indian Standard contains provision which through reference in this text, constitutes provision of this standard. At the time of publication, the edition indicated was valid. All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent edition of the standard indicated below: IS No. Title 14272 (Part 1): Automotive vehicles — Types — 1995 Terminology : Part | Three and four wheelers 3 TERMINOLOGY For the purpose of this standard the following definitions shall apply. 3.1 Steering Effort It means the effort applied to the steering control in order to steer the vehicle. 3.2 Steering Force It means all the forces operating in the steering transmission, 3.3 Test Turning Circle It means the circle within which are located the projections on to the ground plane of all the points of the vehicle, excluding the external mirrors and the ‘ction indicators, when the vehicle is driven in acircle. 3.4 Vehicle It means any motor vehicle as defined in IS 14272 (Part 1), 4 FEATURES OF TEST TRACK ‘The test track shall be an area flat, clear, smooth, dry, covered with concrete or similar material, sufficiently manoeuvres. 5 PREPARATION OF THE VEHICLE. large to carry out the required 5 The vehicle shall conform in all its parts, components and systems to the design and/or production series as applicable. 5.2 The vehicle shall be run-in as per the practice recommended by the vehicle manufacturer. 5.3 The adjustments of fuel system, ignition system, ‘grade and quantity of lubricants for the various moving, parts, adjustment of brakes, clutch, idling speed, etc, shall conform to the recommendations of the ‘manufacturer. 5.4 Prior to test, it shall be ensured that the vehicle including all its parts, components and systems attained a stable temperature normal to the vehicle operation 5.5 The vehicle shall be loaded to the maximum total weight specified by the manufacturer and the load distribution between the axles shall be as recommended by the manufacturer, 5.6 The vehicle shall be fitted with tyres which have not covered more than 10 percent of its expected life. Tread depth measurement may be used to assess the tyre life. The tyres shall be inflated in the cold condition to the pressures specified by the vehicle ‘manufacturer. 5.7 Ifthe vehicle is fitted with power assisted steering, the pressure setting of the assistance shall be as per the recommendations of the vehicle manufacturer. 5.8 The steering geometry shall be within the limits, specified by the manufacturer. 6 TEST CONDITIONS 6.1 The fitment and operation of all instruments shall be such as not to hamper the visibility or freedom of the driver to have proper control of the vehicle at all the times. 6.2 In the case of vehicles where the steered wheels are driven, the test shall be conducted with the drive connected. If the steered wheel drive is optional the test shall be conducted with drive disconnected,IS 11948 ; 1999 7 EVALUATION OF STEERING EFFORT 7.1 Normal Mode Test 7.l.1 The vehicle shall be driven from straight ahead into a spiral ata speed of 10 knv/h. The steering effort shall be recorded for the whole operation. 7.1.2 The peak effort at or before reaching the Test Turning Radius, as indicated by the predetermined number of turns of the steering wheel or steering angle, shall be recorded. 7.1.3 Peak effort values of duration less than 0.2 seconds shall be discarded, that is peaks on graphs to, be made flat with a duration of 0.2 seconds. Record this as the maximum steering fore 7.1.4 One steering movement shall be made to the right and one to the left. 7.2 Incase of vehicles with power steering, additional test as specified in 7.1.1 to 7.1.4 shall be conducted with the power supply to the steering disconnected, 7.3 If a steering torque meter is issued, the steering effort shall be calculated from steering torque by dividing it by the steering wheel radius. 7.4 The maximum permitted steering time, maximum, permitted steering effort and the test turning radius, is given in Table I for the conditions specified in 7.1 and 7.2. 7.5 The steering effort shall not exceed the values, given in Table 1. 7.6 In the case of vehicles with the power assisted steering, an additional test shall be conducted with the power supply to the steering disconnected. 7.6.1. Repeat the test specified in 7.1 to 7.4 as per the details given in Table | 7.6.2 The steering effort shall not exceed the values given in Table | 8 VEHICLE CHARACTERISTICS Vehicle characteristics declared by the vehicle manufacturer to we testing agency shall contain at least the details given in Annex A. NOTE — If the vehicle, submited for type approval ofthe ‘ehicte contain te details given in Annex A, itis mot necessary to submit them again, 9 CHANGES IN VEHICLE CHARACTERISTI: 9.1 In case the test is conducted for verification of compliance to statutory requirements the following, shall be cartied out. 9.2 Every modification to vehicle characteristics declared in accordance with 8 shall be intimated by the manufacturer to the testing agency. The testing agency may then consider, whether: a) the model with the changes specifications still complies with the requirements of this stand- ard; oF b) any further verification is required to establish compliance to this standard. 9.3. Changes where testing is considered necessary for establishing compliance to this standard are as, follows — Any increase of weight on steered axle in excess of 10 percent in case of Mi and Ni type of vehicles and 5 percent for other vehicles. Any increase in wheel base in excess of 10 percent in case of Mi and Ni type of vehicles and 5 percent for other vehicles. Table 1 Requirements of Steering Control Effort (Clauses 7.4, 7.5, 7.6.1 and 76.2) ‘St Vehicle Category” Normal Mode (ee 7.1) With Power Disconnect Mode (see 7.6) No. A Maximum Time TestTuming Maximum Time Turing Effort (3) -Radivs(m)— Effort (9) Radius (my (aN) (see Note 1) (da) wo @ oe 4 0 © a ®) » Mi 15 4 12 30 4 20 i Mz 15 4 2 30 4 20 iid) My 20 4 2 45 6 20 ES) Ni 20 4 2 3% 4 20 ») N 20 4 2 40 4 2» wi) N 20 4 2 45 6 20 (see Note 2) NoTES 1 OF full lock if 12 isnot attainable 2.50 for rigid vehicles with two or more stored axles excluding self tracking equipment. "The category of vehicles are defined in IS 14272 (Part 1),— Any decrease in steering wheel dia [see 9.3 (a) —— Any change in steering linkage/steering gear box ratio which decreases the number of turns of steering wheel from lock to lock. — Type of construction of steering gear box (such as recirculating ball type to rack and pinion type, power steering, etc) — An inerease of caster angle. — Increase of tyre size. — Change of tyre type from dia to radial ply. — Any change in wheel lock angle that affects the test turning circle. — Increase in number of axles. gonal or cross ply ANNEX A a) b) °) (Clause 8) VEHICLE CHARACTERISTICS Model: A.2. Number of axles (Steered/Non-steered): AB Ad Gross vehicular weight (GVW): Maximum recommended mass for: Front axle Rear axle: Intermediate axle: A-5 Wheel A-6 Track of steered axle (s) (Laden): se (Laden): AT Steering gear type: A-8 Steering gear ratio: A-9 Steering wheel diameter: A-10 Tyre size and ply rating and tyre pressure: AcL Tyre type (radial/diagonaliem): AcI2 Wheel lock angle: Taner Left Right A-13 Number of steering wheel rotations from lock to lock: A-14 Caster angle (Laden) A-1I5 Minimum turning circle diameter: IS 11948 : 1999 If steered axle becomes driven: In the case of decrease in the steering wheel diameter, if the effort calculated trom the pre- vious test using the new steering wheel diameter is within limits, a re-test need not be carried out. Changes other than those listed above, are considered to be having no adverse effect on steering effort In case of fulfillment of criterion specified in 9.2 (a) or after results of further verification as per 9.2 (b) are successful, the test results shall be validated for the changes carried out, Outer A-16 Coordination of outermost point which defines the turning circle: A-I7 Pressure setting in case of power steering:TS 11948 : 1999 ANNEX B (Foreword) COMMITTEE COMPOSITION Automotive Testing and Performance Evaluation Sectional Committee, TED 8 Chairman SURI, RAMAKRISHNAN 28,1Cross Road, Kasturi Bai Nagar ‘Adyar, Chennat 600020 Members Representing Suri R. RG. MENON Ashok Leyland Lid. Chennai ‘SHUR, C, BALAKRISHANAN (Alternate) ‘Sky RAsAT NANDI Association of Indian Automobile Miss, New Delhi Sut S. G. SHAM (Alternate) Suet V. K, BHATIA Association of State Road Transport Undertakings, New Dethi Sut Higa LAL. (Altemate) Suet KE. TakAvaLE Automotive Research Assn of India Ltd, Pune Suet Axnak BaDUSH (Alternate) SHRUT. M, BALARAMAN Bajaj Auto Lid, Pune Siint V. M, Manet. (Alternate) ‘Stil V. M. MuNDADA Bajaj Tempo Ld, Pune Su RM. KaNITxaR (Alternate) Sui §. R, TAPADE Central Institue of Road Transport, Pune Shi P. C, BaRuatta (Alternate) SuRIR. S. Dass Central Farm Machine Training and Testing Institute, Buda ‘Sunt MLL. Metira (Alternate) Shiai P. K. Sana ‘Controlterate of Quality Assurance (Vehicles) [DGAQWY)]. (May BALWINDER SINGH (Alternate) Ministry of Defence. Ahmednagar ‘Suigi Dines T¥AGH Daewoo Motors India Ltd, New Delbi ‘Siukt SuavAa PaTNark (Alternate) Sgt N. K, KaUsiau ‘Dte General of Supplies & Disposals, New Delhi SiuesS. K. Gautan (Alternate) Shai S. K. BRAK Dept of Industrial Development, New Del Sixt RK. Tetpar (Alternate) Suet Veen Marie Royal Enfield Motors Ltd, Chennai Siiet K. C. JAIN scons Lid, Faridabad Sine R. K. Guera (Alternate) Suet S. B. GuPra Hero Honda Motors Ltd, New Delhi ‘Sigs HARurT SINGH (Alternate) ‘Sins U, K. KIN Hindustan Motors Lid. Hooghly Suet M. G. JainoRaN (Alternate) De K. K, Gaxit Indian institute of Petroleum. Dehradun Siitt MUKESH SAXENA (Alternate) ‘Sunt P. V, BHANDARE Kinetic Engg Ltd, Pune Sun. K. MUKHERIEE ‘Mahindra & Mahindra Lid, Bombay Sut Z, A. MUiAWAR (Alternate) Suet. V. RAO. Maruti Udyog Ltd, Gurgaon Sut P, PANDA (Alternate) ‘Sint S, N, SRINIVASAN Premier Automobiles Ltd, Bombay ‘Shiki K, D. DIGHE (Alternate) DY. SATYANARAVANA Standing Committee (Technical & Stores) CIRT, Pune Suni M. L. Gone (Alternate) Set LaKHINDER SINGH ‘Swaraj Mazda Lid, Chandigarh Sige S. R. AGRAWARI (Alternate) Sun A. T, PHATAK ‘Tata Engg & Loco Co Ltd, Pune ‘Suits A. V, KULKARNI (Alternate) Simi RC, Sena Vehicle Research & Dev Estt, Ahmednagar ‘Stat R. RAIARAMAN (Alternate) ‘Suki M, K. MISHRA. Vehicle Factory, Jabalpur Suet RG, KaReMOnE (Alternate) SSRI P, N, RANGAN Volvo India Pvt Lid, Bangalore Suet A.R.Gutant, Director General, BIS (Es-officio Member) Director (Transport Engg) Member Secretary SuRIA. K. NAGPAL Aaditional Director (Transport Engg), BISBureau of Indian Standards BIS is a statutory institution established under the Bureau of Indian Standards Act, 1986 to promote harmonious development of the activities of standardization, marking and quality certification of goods and attending to connected matters in the country. Copyright BIS has the copyright of all its publications. No part of these publications may be reproduced in any form without the prior permission in writing of BIS. This does not preclude the free use, in the course of implementing the standard, of necessary details, such as symbols and sizes, type or grade designations. Enquiries relating to copyright be addressed to the Director (Publications), BIS. 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