DRAFT SOUTH AFRICAN STANDARD (DSS): PUBLIC ENQUIRY STAGE

Size: px

Start display at page:

Download "DRAFT SOUTH AFRICAN STANDARD (DSS): PUBLIC ENQUIRY STAGE"

Grant Miller
5 years ago
Views:

1 Document number 022/SANS 1496 Reference SANS 1496 DRAFT SOUTH AFRICAN STANDARD (DSS): PUBLIC ENQUIRY STAGE Date of circulation Closing date Number and title: SANS 1496:XXXX Wheel flaps fitted to motor vehicles Remarks: PLEASE NOTE: The technical committee, SABS/TC 022 responsible for the preparation of this standard has reached consensus that the attached document should become a South African standard. It is now made available by way of public enquiry to all interested and affected parties for public comment, and to the technical committee members for record purposes. Any comments should be sent by the indicated closing date, either by mail, or by fax, or by to SABS Standards Division Attention: Compliance and Development department Private Bag X191 Pretoria 0001 Fax No.: (012) (for attention: dsscomments) dsscomments@sabs.co.za The hyperlink to commenting template on the SABS website for external users is: ype=1 Any comment on the draft must contain in its heading the number of the clause/subclause to which it refers. A comment shall be well motivated and, where applicable, contain the proposed amended text. The public enquiry stage will be repeated if the technical committee agrees to significant technical changes to the document as a result of public comment. Less urgent technical comments will be considered at the time of the next amendment. THIS DOCUMENT IS A DRAFT CIRCULATED FOR PUBLIC COMMENT. IT MAY NOT BE REFERRED TO AS A SOUTH AFRICAN STANDARD UNTIL PUBLISHED AS SUCH. IN ADDITION TO THEIR EVALUATION AS BEING ACCEPTABLE FOR INDUSTRIAL, TECHNOLOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT SOUTH AFRICAN STANDARDS MAY ON OCCASION HAVE TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL TO BECOME STANDARDS TO WHICH REFERENCE MAY BE MADE IN LAW. AZ /03/14 sabs pta

2 ISBN XXXXXXXX SANS 1496:2017 SOUTH AFRICAN NATIONAL STANDARD Wheel flaps fitted to motor vehicles Published by the South African Bureau of Standards 1 Dr Lategan Road Groenkloof Private Bag X191 Pretoria 0001 Tel: Fax: SABS

3 This page has been left blank intentionally

COPYRIGHT PROTECTED DOCUMENT In terms of the Standards Act 8 of 2008, the copyright in all South African National Standards or any other publications published by the SABS Standards Division, vests

4 COPYRIGHT PROTECTED DOCUMENT In terms of the Standards Act 8 of 2008, the copyright in all South African National Standards or any other publications published by the SABS Standards Division, vests in the SABS. Any use of South African National Standards is limited to use specifically prescribed by the SABS. In the case of a South African National Standard based on an international standard, ownership of the copyright vests in the organization from which the SABS adopted the standard, whether it be under licence or membership agreement. The SABS is obliged to protect such copyright and is authorized to make the relevant international organization aware of any misuse thereof. Unless exemption has been granted, no extract or full text of any South African National Standard may be copied, reproduced, stored in a retrieval system or transmitted in any form or by any means without prior written permission from the SABS Standards Division. This does not preclude the free use, in the course of implementing the standard, of necessary details such as symbols, and size, type or grade designations. If these details are to be used for any purpose other than implementation, prior written permission must be obtained. Details, advice and limitations of use can be obtained from the Manager: Standards Sales and Information Services. Tel: +27 (0) sales@sabs.co.za SABS Standards Division The objective of the SABS Standards Division is to develop, promote and maintain South African National Standards. This objective is incorporated in the Standards Act, 2008 (Act No. 8 of 2008). The SABS continuously strives to improve the quality of its products and services and would therefore be grateful if anyone finding an inaccuracy or ambiguity while using this standard would inform the secretary of the technical committee responsible, the identity of which can be found in the foreword. Buying Standards Contact the Sales Office for South African and international standards, which are available in both electronic and hard copy format. Tel: +27 (0) sales@sabs.co.za South African National Standards are also available online from the SABS Webstore Information on Standards SABS Customer Services provide comprehensive standards-related information on national, regional and international standards. Tel: +27 (0) / info@sabs.co.za

5 Table of changes Change No. Date Scope Foreword This South African standard was prepared by National Committee SABS/TC 022, Construction of vehicles, in accordance with procedures of the South African Bureau of Standards, in compliance with annex 3 of the WTO/TBT agreement. This document was approved for publication in xxxx This document supersedes SANS 14936:2008 (edition 1.4). This document is referenced in the National Regulator for Compulsory Specifications Act, 2008 (Act No. 5 of 2008). Annex A is for information only. Compliance with this document cannot confer immunity from legal obligations.

6 Contents Page Foreword 1 Scope Definitions General requirements Requirements for conventional wheel protection systems Requirements for wheel protection systems for some non-steerable wheels... 9 Annex A (informative) General comments on effect of aerodynamic vehicle styling Bibliography

7 This page is intentionally left blank 2

8 Wheel flaps fitted to motor vehicles 1 Scope 1.1 This standard covers the requirements for wheel protection systems fitted to motor vehicles of gross vehicle mass or gross combination mass exceeding 3,5 t and to trailers of gross vehicle mass exceeding 3,5 t, for the purpose of providing other road users with some protection against stones, surface water, mud or other debris thrown up by the vehicle tyres. 1.2 This standard also covers a) requirements for wheel guards and outer valances, b) wheel flaps attached to wheel guards, and c) wheel flaps for single axle or rear wheel of multiple axles of motor vehicles and trailers when conventional wheel guards are not fitted and the wheels are covered by the floor of the vehicle body. 1.3 This standard does not cover a) the rearmost axles of an end-tipping semi-trailer of the scissors type, that pivot about the centre point of the axle or the axle unit, b) the rear axle(s) of a truck tractor where the semi-trailer is equipped with the wheel flaps to guard the rear axle(s) of the truck tractor, c) recovery vehicles of exceeding 3,5 t, and d) wheels to which the fitment of wheel protection systems is incompatible to the vehicle structure. 2 Definitions For the purposes of this document the following definitions apply. 2.1 outer valance component located approximately within a vertical plane that is parallel to the longitudinal plane of the vehicle 2.2 tyre width that part of the tyre which, under conditions of normal use, is in contact with the road, and that is measured at right angles to the peripheral line of the tread. In the case of a double wheel, the width is measured across both tyres and includes the space between them 3

9 2.3 wheel flap device attached to the vehicle body or to the wheel guard in a lateral vertical plane of the vehicle or at a small angle to it and extending towards the road surface behind the wheel 2.4 wheel guard mudguard rigid or semi-rigid component intended to deflect the water, mud or other debris thrown up by the vehicle tyres in motion and to direct it towards the ground NOTE The wheel guard may entirely or partially form an integral part of the vehicle bodywork or other parts of the vehicle such as the lower part of the load platform, etc. 2.5 wheel protection system system intended to reduce stones, surface water, mud or other debris being thrown up by the vehicle tyres in motion NOTE It is variously made up of wheel guard, wheel flaps and outer valances. 3 General requirements 3.1 For the purposes of the requirements of this standard, the vehicle shall be in the following condition: a) The vehicle shall be without load, with bodywork and in running order (including coolant, oils, fuel, tools, spare wheel and a driver). For the tractor unit of an articulated vehicle, the trailer shall be attached, for vehicles fitted with demountable body systems; an empty body shall be attached. In all cases, the wheels shall be in the straight ahead position. b) In the case of semi-trailers for articulated vehicles, the load platform shall be horizontal. c) Tyres shall be in nominally new condition. For the purpose of determining the width, the labelling (marking), decorations, protective bands or ribs on tyre walls shall not be included. The tyre width shall be measured at the height of the wheel centre. 3.2 Wheel protection systems shall comply with 3.3, 3.4, 3.5, 3.6 and clause 4 of this standard. However the wheel protection systems for non-steerable rear wheels fitted to motor vehicles where the wheels are normally covered by the floor of the vehicle body wheel protection systems shall comply with 3.3, 3.4, 3.5, 3.6 and either clause 4 or clause Wheel protection systems shall be designed not to damage tyres. NOTE It is essential that wheel protection devices permit adequate air flow around tyres and brake hub assemblies to avoid overheating. 3.4 Where a vehicle is fitted with a lifting axle or axles the wheel protection systems shall cover a) all wheels when the lifting axle is lowered, and b) the wheels remaining in contact with the road when the lifting axle is raised. 3.5 Where an entire axle is centrally pivoted, so that it can move in a horizontal arc, the wheel protection system shall comply with the requirements for non-steerable wheels if mounted on the pivoting section. If it is not mounted on the pivoting section, it shall comply with the requirements for steerable wheels. 4

10 3.6 For motor vehicles fitted with a) steerable wheels, the distance between a longitudinal plane touching the outer edge of a tyre and the inside edge, or the inside edge of any lip, of the outer valance shall not exceed 100 mm, and b) non-steerable wheels, the distance between a longitudinal plane touching the outer edge of a tyre and the inside edge of the outer valance shall not exceed 75 mm unless the radius of the lower edge of the outer valance specified in does not exceed 1.0 R, in which case it shall not exceed 100 mm (see figure 1). NOTE It is recommended that inner valances should be provided whenever practicable. Figure 1 Total width of wheel guard and position of outer valance 3.7 Each wheel flap shall be legibly and indelibly marked with the manufacturer's name, trade name or trademark. NOTE For more information on the effects of aerodynamic vehicle styling, see annex A. 5

11 4 Requirements for conventional wheel protection systems 4.1 Wheel guards The wheel guard shall be positioned to cover the area directly above, to the front and to the rear of the tyre(s) as follows: a) For single axles and multiple axles where the distance between tyres on adjacent axles is greater than 300 mm, the front edge (see figure 2 point C) shall extend forward to reach a line such that Ø = 30 maximum for steerable wheels or 20 maximum for non-steerable wheels above the horizontal and passing through the wheel centre. The rear edge (see figure 2 point A) shall extend downwards so that it is not more than 100 mm above a horizontal line through the wheel centre. Figure 2 Wheel guards, wheel flaps and outer valances for single axles and multiple axles where the distance between tyres is greater than 300 mm non-steerable wheels b) In the case of multiple axles where the distance between the tyres (d) on adjacent axles is not more than 350 mm, the wheel guard shall be in accordance with figure 3. NOTE This applies for two or more axles. 6

12 Figure 3 Wheel guards, wheel flaps and outer valances for multiple axles where the distance between tyres is 350 mm or smaller c) the overall width, q (see figure 1), of the wheel guard shall be at least sufficient to cover the total tyre width, b, or the total width of two tyres, t, in the case of twin wheels, taking into account the extremes of tyre/wheel combinations given by the vehicle manufacturer Where wheel guards consist of several components, there shall be no gaps between or within individual parts when assembled that will permit the exit of spray when the vehicle is in motion. 4.2 Outer valances For single axles and multiple axles where the distance between tyres on adjacent axles is greater than 300 mm, the lower edge of the outer valance shall not exceed the following dimensions and radii from the centre of the wheel (see figure 2): a) Steerable wheels: Front (leading) edge (30 point) Rv = 1.5R Rear (trailing) edge (100 mm point) Rv = 1.5R Top (directly over top of tyre) Rv = 1.5R b) Non-steerable wheels: Front (leading) edge (20 point) Rv = 1.25R Rear (trailing) edge (100 mm point) Rv = 1.25R Top (directly over top of tyre) Rv = 1.25R where R is the radius of the tyre fitted to the vehicle; and Rv is the radial distance of the lower edge of the outer valance. 7

13 4.2.2 In the case of multiple axles where the distance between the tyres on adjacent axles is not more than 350 mm, the outer valances in the spaces between axles shall follow the contour as specified in and extend downwards so that either they are not more than 150 mm above the horizontal line through the wheel centres or the horizontal distance between their lower extremities is not more than 60 mm (see figure 3). NOTE The optimum condition is that there should not be a radial gap between the lower edge of the outer valance and the circumference of the tyre, i.e. a value of R, or less. However, it is accepted that this ideal is not always practicable bearing in mind the allowances necessary for suspension and steering movement plus the closeness of some tyres to the edge of vehicles built to the legally permitted width limit The depth of the outer valance shall be not less than 45 mm to the rear of the vertical centre line of the wheel. NOTE The depth of valances may be progressively reduced forward of the wheel centre There shall be no openings in outer valances or between outer valances and wheel guards that allow spray to be emitted. 4.3 Wheel flaps There shall be no gaps between the lower rear edge of the wheel guard and wheel flaps that will permit the exit of spray A wheel flap shall be of sufficient width to cover the total tyre breadth, b or t as applicable (see figure 1), taking into account the extremes of tyre/wheel combinations given by the vehicle manufacturer, except where the wheel flap is contained within the wheel guard when it shall cover the breadth of the tyre tread The maximum height of the bottom edge shall not exceed a height of either: a) 200 mm; or b) 300 mm on any axle where the radial distance of the lower edge of the outer valancing, Rv, does not exceed the dimensions of the radius of the tyres fitted to the wheels on that axle (see figure 2) The wheel flap shall be not more than 300 mm from the rearmost edge of the tyre except that for multiple axles where the distance between the tyres on adjacent axles is less than 350 mm, a wheel flap shall be fitted only on the rear wheel(s) (see figure 3). A wheel flap shall be fitted behind each wheel where the distance between the tyres on adjacent axles is equal to or greater than 350 mm The rearward deflection of the wheel flap shall not exceed 100 mm when subjected to a force of 3 N per 100 mm of flap width, applied across the width by, for example, a load spreading bar, at a height of 50 mm above the bottom of the wheel flap when it is supported in its operating configuration. 5 Requirements for wheel protection systems for some non-steerable wheels NOTE Reference should be made to 3.2 for a complete description of the wheels covered by this clause. 8

14 5.1 Outer valances For single axles and multiple axles where the distance between tyres on adjacent axles is greater than or equal to 350 mm, the outer valance shall cover the area extending from the underside of the body to a line formed by the tangent at the top of the tyre(s) and between the outer edge of the wheel flap, with which it shall form a seal, and the vertical plane formed by the tangent at the front of the tyre (see figure 4). In the case of multiple axles, an outer valance shall be fitted over each wheel. Figure 4 Valances for multiple non-steerable wheels axles where the distance between tyres is 350 mm or greater There shall be no gaps between the outer valance and the underside of the body that will permit the exit of spray Where wheel flaps are not fitted behind each wheel (see 5.2), the outer valance shall be continuous from the outer edge of the wheel flap to the vertical line at the foremost point of the tyre, point C (see figure 5) on the leading axle. Figure 5 Valances for multiple non-steerable wheels axles where the distance between tyres is less than 350 mm 9

15 5.2 Wheel flaps Wheel flaps shall extend to the underside of the vehicle structure. There shall be no gaps that will permit the exit of spray and the wheel flaps shall also comply with 4.3.2, 4.3.3, and Annex A (informative) General comments on the effects of aerodynamic vehicle styling The following aerodynamic styling features may assist in keeping spray propagation to a minimum, thus reducing the density of spray at driver's eye level on vehicles that are following behind: a) cab-mounted air deflectors on articulated vehicles and box vehicles where the bodywork is higher than the cab roof; b) covered sideguards or sideskirts; c) splitter panels (vertical panels between the cab and the trailer) on articulated vehicles with box trailers; and d) a body-mounted or trailer-mounted air deflector on the front surface of the box or trailer body. Bibliography BS AU 200-1A:1984, Spray reduction devices for heavy goods vehicles Specification for design of containment devices. 10

SOUTH AFRICAN NATIONAL STANDARD

ISBN 978-0-626-34898-4 SOUTH AFRICAN NATIONAL STANDARD Motor vehicle tyres and rims Dimensions and loads Part 1: General WARNING This document references other documents normatively. Published by the South