GB/T 44411-2024 PDF EnglishUS$275.00 · In stock · Download in 9 seconds
GB/T 44411-2024: Testing methods of adhesion coefficient for motor vehicle inspection equipment and sites Delivery: 9 seconds. True-PDF full-copy in English & invoice will be downloaded + auto-delivered via email. See step-by-step procedure Status: Valid
Similar standardsGB/T 44411-2024: Testing methods of adhesion coefficient for motor vehicle inspection equipment and sites---This is an excerpt. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.), auto-downloaded/delivered in 9 seconds, can be purchased online: https://www.ChineseStandard.net/PDF.aspx/GBT44411-2024 GB NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA ICS 43.180 CCS R 86 Testing methods of adhesion coefficient for motor vehicle inspection equipment and sites ISSUED ON: AUGUST 23, 2024 IMPLEMENTED ON: MARCH 01, 2025 Issued by: State Administration for Market Regulation; Standardization Administration of the People’s Republic of China. Table of ContentsForeword ... 3 1 Scope ... 4 2 Normative references ... 4 3 Terms and definitions ... 4 4 Test conditions ... 5 5 Test equipment ... 5 5.1 Test device for wheel adhesion coefficient ... 5 5.2 Test device for tractor adhesion coefficient ... 6 6 Test methods ... 7 6.1 Roller surface adhesion coefficient of roller reaction brake test bench ... 7 6.2 Free roller surface adhesion coefficient ... 8 6.3 Flat-plate brake test bench brake plate surface adhesion coefficient ... 9 6.4 Slide plate parking brake test device slide plate surface and inspection station ground adhesion coefficient ... 9 6.5 Roller reaction brake test bench front and rear ground adhesion coefficient ... 9 6.6 Service brake road test lane adhesion coefficient ... 10 6.7 Traction parking brake inspection station road surface adhesion coefficient ... 10 6.8 Parking ramp surface adhesion coefficient ... 10 7. Processing of test results ... 11 Appendix A (Informative) Adhesion coefficient test record format ... 12 Bibliography ... 15 Testing methods of adhesion coefficient for motor vehicle inspection equipment and sites1 ScopeThis document describes the testing methods of adhesion coefficient for motor vehicle inspection equipment and sites, and specifies the technical requirements for test conditions, test equipment and processing of test results. This document applies to the testing of adhesion coefficient for inspection equipment and sites of motor vehicle inspection and testing institutions.2 Normative referencesThe following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the version corresponding to that date is applicable to this document; for undated references, the latest version (including all amendments) is applicable to this document. GB/T 8170-2008, Rules of rounding off for numerical values & expression and judgment of limiting values GB/T 42685-2023, Terminology of power-driven vehicle inspection3 Terms and definitionsFor the purposes of this document, the following terms and definitions, as well as those given in GB/T 42685-2023, apply. 3.1 road test lane Test lane used for road testing of motor vehicle service braking performance. [Source: GB/T 42685-2023, 3.4.13] 3.2 parking ramp Ramp used for road testing of motor vehicle parking braking performance. Description of indexing numbers: 1 – object being tested; 2 – rubber layer; 3 – counterweight; 4 – tension sensor; 5 – traction rope; 6 – fixed pulley; F – horizontal tension. Figure 2 – Schematic diagram of the test device for traction adhesion coefficient 5.2.2 Technical requirements 5.2.2.1 The sum of the masses of the counterweight, rubber layer and tension sensor is (40±2) kg. 5.2.2.2 Rubber layer: The rubber tires are of specification 225/50R18, which are cut, laid flat and pasted together. 5.2.2.3 Tire rubber material: conventional tire (BR) butadiene rubber, Shore hardness 60 HA ~ 75 HA. 5.2.2.4 Tire pattern: The longitudinal pattern shall be consistent with the traction direction (i.e., the direction of vehicle travel), and the tire pattern depth shall be no less than 3.2 mm. 5.2.2.5 Rubber layer contact area: 200 mm × 140 mm. 5.2.2.6 Tension sensor measurement range: 0 N ~ 500 N, indication error: no more than ±1%. 5.2.2.7 The maximum value holding time of the display device shall not be less than 5 s.6 Test methods6.1 Roller surface adhesion coefficient of roller reaction brake test bench 6.1.1 Place the test wheel of the wheel adhesion coefficient test device on the upper generatrix of the roller to be tested and apply a normal force to the test wheel in accordance with the provisions of 5.1.2.1. 6.2.4 Repeat the test 6 times according to the method specified in 6.2.3 and calculate the adhesion coefficient according to Formula (1). 6.2.5 Test the center and both ends (about 100 mm from the edge of the roller) of the roller. For equipment in use, test the commonly used positions and the most severely worn positions, and take the minimum value as the adhesion coefficient test result. 6.3 Flat-plate brake test bench brake plate surface adhesion coefficient 6.3.1 Place the rubber layer and counterweight of the traction adhesion coefficient test device on the brake plate to be tested. Along the braking force test direction, gradually apply a tensile force (F) parallel to the longitudinal geometric center line of the surface of the plate to be tested to the tension sensor (see Figure 2). Read the maximum value measured by the tension sensor when the rubber layer and the counterweight go from static to relative slippage, which is the adhesion force. 6.3.2 Repeat the test 6 times according to the method specified in 6.3.1 and calculate the adhesion coefficient according to Formula (3). Where: m – the sum of the masses of the counterweight, rubber layer and tension sensor, in kilograms (kg); g – acceleration due to gravity, taken as 9.80 m/s2. 6.3.3 Test the front, middle and rear positions of the brake plate surface. For equipment in use, test the commonly used positions and the most severely worn positions, and take the minimum value as the adhesion coefficient test result. 6.4 Slide plate parking brake test device slide plate surface and inspection station ground adhesion coefficient 6.4.1 Test the adhesion coefficient according to the methods specified in 6.3.1 and 6.3.2. 6.4.2 Test the surface of the slide plate and the front, middle and rear positions of the inspection station. For equipment in use, test the commonly used positions and the most severely worn positions, and take the minimum value as the adhesion coefficient test result. 6.5 Roller reaction brake test bench front and rear ground adhesion coefficient 6.5.1 Test the adhesion coefficient according to the methods specified in 6.3.1 and 6.3.2. 6.5.2 Test the front, middle and rear positions of the ground in front of and behind the workstation. For the workstations in use, the commonly used positions and the positions with the most severe wear shall be tested, and the minimum value shall be taken as the adhesion coefficient test result. 6.6 Service brake road test lane adhesion coefficient 6.6.1 Test the adhesion coefficient according to the methods specified in 6.3.1 and 6.3.2. 6.6.2 Divide the road test lane into left and right sides; test the front, front-center, center, center-rear and rear positions. For the road test lane in use, the commonly used positions and the most severely worn positions shall be tested, and the minimum value is taken as the adhesion coefficient test result. 6.7 Traction parking brake inspection station road surface adhesion coefficient 6.7.1 Test the adhesion coefficient according to the methods specified in 6.3.1 and 6.3.2. 6.7.2 Divide the road surface of the inspection station into left and right sides, and test the front, middle and rear positions. For the working stations in use, the commonly used positions and the most severely worn positions shall be tested, and the minimum value shall be taken as the adhesion coefficient test result. 6.8 Parking ramp surface adhesion coefficient 6.8.1 Place the rubber layer and counterweight of the traction adhesion coefficient test device on the surface of the ramp to be tested. Slowly apply a tensile force (F) parallel to the longitudinal geometric center line of the ramp surface to the tensile force sensor along the parking brake force test direction (see Figure 3) to measure the adhesion force of the rubber layer and the counterweight from static to relative slippage. Description of indexing numbers: 1 – counterweight; 2 – rubber layer; 3 – tension sensor; ......Source: Above contents are excerpted from the full-copy PDF -- translated/reviewed by: www.ChineseStandard.net / Wayne Zheng et al. Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of English version of GB/T 44411-2024 be delivered?Answer: The full copy PDF of English version of GB/T 44411-2024 can be downloaded in 9 seconds, and it will also be emailed to you in 9 seconds (double mechanisms to ensure the delivery reliably), with PDF-invoice.Question 2: Can I share the purchased PDF of GB/T 44411-2024_English with my colleagues?Answer: Yes. The purchased PDF of GB/T 44411-2024_English will be deemed to be sold to your employer/organization who actually paid for it, including your colleagues and your employer's intranet.Question 3: Does the price include tax/VAT?Answer: Yes. Our tax invoice, downloaded/delivered in 9 seconds, includes all tax/VAT and complies with 100+ countries' tax regulations (tax exempted in 100+ countries) -- See Avoidance of Double Taxation Agreements (DTAs): List of DTAs signed between Singapore and 100+ countriesQuestion 4: Do you accept my currency other than USD?Answer: Yes. www.ChineseStandard.us -- GB/T 44411-2024 -- Click this link and select your country/currency to pay, the exact amount in your currency will be printed on the invoice. Full PDF will also be downloaded/emailed in 9 seconds.How to buy and download a true PDF of English version of GB/T 44411-2024?A step-by-step guide to download PDF of GB/T 44411-2024_EnglishStep 1: Visit website https://www.ChineseStandard.net (Pay in USD), or https://www.ChineseStandard.us (Pay in any currencies such as Euro, KRW, JPY, AUD).Step 2: Search keyword "GB/T 44411-2024". Step 3: Click "Add to Cart". If multiple PDFs are required, repeat steps 2 and 3 to add up to 12 PDFs to cart. Step 4: Select payment option (Via payment agents Stripe or PayPal). Step 5: Customize Tax Invoice -- Fill up your email etc. Step 6: Click "Checkout". Step 7: Make payment by credit card, PayPal, Google Pay etc. After the payment is completed and in 9 seconds, you will receive 2 emails attached with the purchased PDFs and PDF-invoice, respectively. Step 8: Optional -- Go to download PDF. Step 9: Optional -- Click Open/Download PDF to download PDFs and invoice. See screenshots for above steps: Steps 1~3 Steps 4~6 Step 7 Step 8 Step 9 |
