Detail of JT/T 782-2020

Introduction of JT/T 782-2020

Performance requirements and test methods of tyre blow-out emergency safety device for commercial vehicle 1 Scope This standard specifies the general requirements, post-installation performance requirements and test methods of tyre blow-out emergency safety device for commercial vehicle. This standard is applicable to M2, M3, N1, N2 and N3 vehicles, as well as commercial vehicles in the combination vehicles composed of them and trailers of Category O, and may be used as a reference for other types of vehicles. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated reference, only the edition cited applies. For undated references, the latest edition (including any amendments) applies. GB/T 2423.1-2008 Environmental testing for electric and electronic products - Part 2: Test methods - Tests A: Cold GB/T 2423.2-2008 Environmental testing for electric and electronic products - Part 2: Test methods - Tests B: Dry heat GB/T 3730.1 Motor vehicles and trailers - Types - Terms and definitions GB/T 5909-2009 Performance requirements and test methods of commercial vehicles wheels GB/T 10125-2012 Corrosion tests in artificial atmospheres - Salt spray tests GB/T 12534 Motor vehicles - General rules of road test method GB/T 15089 Classification of power-driven vehicles and trailers GB/T 28046.3-2011 Road vehicles - Environmental conditions and testing for electrical and electronic equipment - Part 3: Mechanical loads QC/T 242 Static unbalance requirements and test methods of vehicle wheels   3 Terms and definitions For the purposes of this document, the terms and definitions given in GB/T 3730.1 and GB/T 15089 and the following apply. 3.1 tyre blow-out emergency safety device auxiliary device installed inside the pneumatic tyre, which, in case of tyre blow-out, can ensure that the driving direction of a vehicle is controllable within a certain driving distance, the braking is effective and the direction is stable 4 Technical requirements 4.1 General requirements 4.1.1 After being tested for dry heat and cold resistance, salt spray resistance, mechanical vibration resistance and durability in accordance with the methods specified in Annex A, the tyre blow-out emergency safety device for vehicle shall be free from obvious corrosion, displacement, looseness, cracking or fracture. 4.1.2 After the tyre blow-out emergency safety device is installed on the wheel whose tyre has been treated with dynamic balancing, the total unbalance of the wheel shall meet those specified in QC/T 242. 4.1.3 Under normal use conditions, the tyre blow-out emergency safety device installed in the tyre shall not contact with the inner wall of the tyre, and shall be free from obvious deformation, loosening, cracking or fracture and other failures, or any adverse effects on the normal use of the tyre. 4.1.4 In case of loss of pressure of the vehicle tyre due to blow-out, the tyre blow-out emergency safety device shall be able to prevent the tyre body from separating from the rim within the controllable driving distance. 4.2 Requirements for post-installation performance 4.2.1 Steering performance after tyre blow-out 4.2.1.1 According to the test method specified in 5.2.3.1, in case of blow-out of tyre on the side of the steering axle during straight-line driving, the tyre blow-out emergency safety device shall ensure that the vehicle can be kept in the predetermined track by operating the steering wheel, and that the increment of tangential force acting on the outer edge of the steering wheel during driving is not greater than 50 N.

Contents of JT/T 782-2020

Foreword i 1 Scope 2 Normative references 3 Terms and definitions 4 Technical requirements 5 Test methods Annex A (Normative) Bench test of tyre blow-out emergency safety device