GB/T 4502-2023 English PDF (GBT4502-2023)

Delivery: 3 seconds. Download true-PDF + Invoice.
Get QUOTATION in 1-minute: Click GB/T 4502-2023
Historical versions: GB/T 4502-2023
Preview True-PDF (Reload/Scroll if blank)

GB/T 4502-2023: Laboratory test methods for passenger car tyres capabilities
GB/T 4502-2023
GB
NATIONAL STANDARD OF THE
PEOPLE'S REPUBLIC OF CHINA
ICS 83.160.10
CCS G 41
Replacing GB/T 4502-2016
Laboratory test methods for passenger car tyres capabilities
(ISO 10191:2021, Passenger car tyres - Verifying tyre capabilities -
Laboratory test methods, MOD)
ISSUED ON: MAY 23, 2023
IMPLEMENTED ON: DECEMBER 1, 2023
Issued by: State Administration for Market Regulation;
Standardization Administration of PRC.
Table of Contents
Foreword ... 3
1 Scope ... 7
2 Normative references ... 7
3 Terms and definitions ... 7
4 Test equipment and its precision ... 8
5 Test samples ... 9
6 Test methods ... 10
7 Judgment rules ... 18
8 Test report ... 19
Appendix A (Informative) Comparison list of structure numbers between this document
and ISO 10191:2021 ... 21
Appendix B (Informative) List of technical differences between this document and ISO
10191:2021 and their reasons ... 23
Appendix C (normative) Shape and dimensions of the pressing block for bead unseating
... 26
Reference ... 27
Laboratory test methods for passenger car tyres capabilities
1 Scope
This document describes the laboratory test methods for performance testing of
passenger car tyres, including test equipment and its precision, test conditions, test
procedures, judgment rules and test reports.
This document includes the bead unseating resistance test, strength performance test,
high-speed test, endurance test and low-pressure performance test for tyres. Of the test
methods proposed, only the applications of some test methods depend on the type of
tyre to be tested (tube or tubeless tyres, diagonal tyres or radial tyres, etc.).
The test methods listed in this document are not suitable for grading the performance
or quality level of tyre products.
This document is applicable to new passenger car pneumatic tyres and retreaded
passenger car pneumatic tyres. Other tyres can be tested with reference to this document
after consultation and agreement of relevant parties.
2 Normative references
The following documents contain the provisions which, through normative reference in
this document, constitute the essential provisions of this document. For the dated
referenced documents, only the versions with the indicated dates are applicable to this
document; for the undated referenced documents, only the latest version (including all
the amendments) is applicable to this document.
GB/T6326 Tyre terms and definitions (GB/T 6326-2014, ISO 4223-1:2002, NEQ)
GB/T 8170 Rules of rounding off for numerical values and expression and judgment
of limiting values
3 Terms and definitions
Terms and definitions defined in GB/T 6326 and the following apply to this document.
3.1 parasitic tread block chunking; PTBC
A defect characterized by rubber pieces separated from the tyre tread or tearing without
exposing the tyre reinforcing material (such as carcass ply, belt, etc.).
4.2 Strength testing machine
4.2.1 The testing machine shall be equipped with a sufficiently long cylindrical metal
indenter, and the end of the indenter is hemispherical with a diameter of 19 mm±0.5
mm.
4.2.2 The indenter device shall be able to apply force gradually and incrementally, and
the accuracy of the force and displacement indicator is ±1% of the full scale.
4.2.3 The accuracy of the displacement velocity of the indenter shall be ±3% of the full
scale.
4.3 High-speed and endurance testing machine
4.3.1 The drum diameter of the testing machine shall be 1700 mm±17 mm.
4.3.2 The surface of the test drum of the testing machine shall be a smooth steel surface,
and its width shall not be less than the total section width of the test tyre.
4.3.3 The loading capacity of the test loading device shall meet the requirements of the
test method, and its accuracy is ±1% of the full scale.
4.3.4 The speed capability of the test machine drum and test equipment shall meet the
requirements of the test method, and its accuracy shall be +2 0 km/h.
4.3.5 The radial runout of the drum of the testing machine shall not exceed 0.25 mm.
4.3.6 The ambient temperature measuring device shall be set within the range of 150
mm~1000 mm from the test tyre.
4.4 Inflation pressure gauge
The accuracy of the inflation pressure gauge is ±5 kPa.
5 Test samples
According to the needs of the test, the test samples are 3 to 5 identical tyres, which are
used for bead unseating resistance test and strength test, high-speed test, endurance test
and low-pressure performance test respectively. Therein,
-- for the bead unseating resistance test and the strength test, the same test sample
can be used, or different test samples can be used respectively;
-- for the second high-speed test of passenger car tyres whose maximum speed
exceeds 300 km/h as specified in 6.3.1.6, the same test sample can be used for
the first and second high-speed tests, or different test samples can be used
be noted in the test report that each test point is "not unseated" or "unseated"; if the
pressing block for bead unseating slipped or touched the rim, it shall be indicated.
6.2 Strength test
6.2.1 Test conditions and test preparation
6.2.1.1 The test rim should comply with the provisions of GB/T 2978 or relevant
industry technical documents on measuring rims.
NOTE: The relevant industry technical documents are only applicable to the specifications of passenger
car tyres that are not within the scope of GB/T 2978.
6.2.1.2 Install the test tyre on the test rim and inflate it to the pressure specified in Table
1.
6.2.1.3 The inflated test tyre and rim assembly shall be stood at an ambient temperature
of 18 °C to 36 °C for at least 3 hours. If the same set of tyre and rim assembly used for
the bead unseating resistance test is used, the test can be continued.
6.2.1.4 Determine 5 roughly equidistant test points along the outer circumferential
direction of the tyre, mark and number them one by one.
6.2.2 Test procedures
6.2.2.1 Readjust the pressure of the test tyre that has been stood for the indicated time
to the specified value in Table 1.
6.2.2.2 Fix the test tyre and rim assembly after correcting the pressure on the strength
testing machine, and conduct the test point by point.
6.2.2.3 The indenter shall be perpendicular to the tread, and press on the pattern block
as close as possible to the centerline of the tread circumference, while avoiding pressing
into the tread groove.
6.2.2.4 The indenter gradually and incrementally applies force (F) to the tyre crown at
a moving speed of 50 mm/min±2.5 mm/min until the tyre crown is pressed through or
the minimum breaking energy value specified in Table 9 is reached. Readjust the
pressure before moving on to the next test point.
6.2.2.5 Measure and record the force (F) and pressed depth (the travel is expressed as
p) at the moment when the indenter stops moving at each test point.
6.2.2.6 Where the indenter cannot continue moving due to contact with the rim and the
tyre has not been punctured, the test point shall be deemed to have passed the test, and
shall be indicated in the test report as "rim is touched and tyre isn't punctured".
tyre cool naturally for 15 minutes to 25 minutes, and measure the tyre pressure within
the specified time, and then check the appearance of the tyre without disassembly after
it has completely cooled.
6.5 Low-pressure performance test
6.5.1 Test conditions and test preparation
6.5.1.1 This test is only applic...