ICS 43.020 T 04 GB NATIONAL STANDARD OF THE PEOPLE S REPUBLIC OF CHINA GB/T 12540-2009 Replacing GB/ T12540-1990 Minimum Turning Circle Diameter, Minimum Turning Clearance Circle Diameter and Out Value Test Method for Motor Vehicles 汽车最小转弯直径 最小转弯通道圆直径和外摆值测量方法 GB/T 12540-2009 How to BUY & immediately GET a full-copy of this standard? 1. www.chinesestandard.net; 2. Search --> Add to Cart --> Checkout (3-steps); 3. No action is required - Full-copy of this standard will be automatically & immediately delivered to your EMAIL address in 0~60 minutes. 4. Support: Sales@ChineseStandard.net. Wayne, Sales manager Issued on March 23, 2009 Implemented on January 01, 2010 Issued by General Administration of Quality Supervision, Inspection and Quarantine (AQSIQ); Standardization Administration (SAC) of the People's Republic of China.
Contents Foreword... 1 1 Scope... 1 2 Terms and Definitions... 1 3 Test Conditions... 4 4 Testing Methods... 4 5 Results and Testing Records... 6 1
Foreword This standard is a revision of "Motor Vehicles - Minimum Turning Diameter - Method of Measurement"(GB/T 12540-1990), and this standard replaces GB/T 12540-1990 from the implementation date. Compared with GB/T 12540-1990, the main revisions in this standard are as follows: - The scope of applicable vehicles was enlarged; - The definitions of turning circle diameter and turning clearance circle were unified according to "Motor Vehicles - Minimum Turning Diameter - Method of Measurement"(GB/T 3730.3); - The definition of out value t was added; - The test conditions were revised; - The measuring method of out value t was added; This standard was proposed by the National Development and Reform Commission. This standard is under the jurisdiction of the National Automotive Standardization Technical Committee. Drafting organization of this standard: National Automobile Quality Supervision Test Center (Xiangfan); Chief drafting staffs of this standard: Zhuxin, Chen Jiaxin, Wang Zuguo, and Zhan Yongmao. The previous editions of standards replaced by this standard are as follows: - GB/T 12540-1990.
Minimum Turning Circle Diameter, Minimum Turning Clearance Circle Diameter and Out Value Test Method for Motor Vehicles 1 Scope This standard specifies the measuring method of minimum turning circle diameter, minimum turning clearance circle diameter and out value for automobile. This standard is applicable to the automobile and the truck combination. 2 Terms and Definitions The following terms and definitions are applicable to this standard. 2.1 Turning circle diameters d1 The diameter of trajectory circle, with the center (for a double-tire, it's the center of the double-tire) of each wheel's tire surface (inside and outside) on flat ground where the handwheel goes to the limit position (see Figure 1). 2.2 Minimum turning circle diameter d Where the handwheel goes to the limit position, the center of the outside vehicle guide wheel tire surface go round on the flat ground, and the bigger diameter of the trajectory circle is the minimum turning circle diameter. 2.3 Turning clearance circle Where the vehicle is turning a corner, the following two circles are the vehicle turning clearance circles (see Figure 2). a) The projection of all the parts of the vehicle(except the rearview mirror, lower vision mirror and antenna, the same below ) on the flat ground is located in the minimum encircle inside the circles - encircle of the turning clearance circle (diameter D1). 1
b) The projection of all the parts of the vehicle on the flat ground is located in the max inner circle outside the circles - inner circle of the turning clearance circle (diameter D2). 2.4 Turning clearance circle width b The turning clearance circle width B is one half of the difference between excircle of the turning clearance circle (diameter D 1) and inner circle of the turning clearance circle ( diameter D2), namely B = ( D 1 - D 2)/2. 2.5 Minimum turning clearance circle The minimum turning clearance circle is the turning clearance circle where the handwheel goes to the limit position. 2.6 Maximum turning clearance circle width The maximum turning clearance circle width is the turning passage width where the handwheel go to the limit position. 2.7 Out value T Where automobile or truck combination is parked in straight line traveling state on the flat ground, draw a projection line paralleling with the vertical center line of the vehicle on the ground along the outermost lateral point of the vehicle; then they start and transfer from straight line traveling to circle traveling on the 25m diameter of the turning clearance circle excircle(except the rearview mirror,lower vision mirror and antenna,count from the outermost lateral part without taking into account the projecting part of the operation - functional isolated plant until the tail enter into this circle entirely ;in this process, the projection of any outer lateral part of the vehicle form a group of outer pendulum trajectory, and the distance between these group trajectory and the projection line of the outermost lateral part of the vehicle on the ground where the vehicle are at a standstill is the out value test (see Figure 3). 2
4.1.4 Each measuring where the automobile turn left and turn right are done, the test results shall be recorded.. 4.1.5 If the difference of the test results of turning left and turning right is within 0.1m,take the average value of the test results of turning left and turning right as the final result of the mobile; otherwise take the larger value of the test results of turning left and turning right as the final result. 4.2 Measurement of the minimum turning clearance circle diameter Measuring method is detailed in 4.1.1 ~ 4.1.5. 4.3 Measurement of out value T 4.3.1 A circle of 25m diameter shall be drawn on the flat ground; the track display device shall be installed in the outermost point of the automobile tail and the ultima thule of the automobile body from the turning center. 4.3.2 Where the automobile is at a status of minimum forward gear and enter into this circumference at a low speed, adjust the handwheel intersection angle and start the ultima thule track display device from the automobile body turning center to make the trajectory fall upon this circumference, then note down the intersection angle position of the handwheel at this moment. 4.3.3 Where the automobile is parked in the straight line traveling State on the flat ground, draw a projection line paralleling with the vehicle vertical center line from the outermost part to the ground; rotate the handwheel to the preselect intersection angle position and maintain it; start the outermost locus of points display device of the tail, and let the automobile move on until the outermost locus of points of the tail intersects with the outermost side projection line done of the vehicle. 4.3.4 The maximum distance between the trajectory formed by the outermost point of the vehicle tail on the ground and the projection line formed by the vehicle pars lateralis on the ground where the vehicle is still shall be measured. 4.3.5 Each test of turning right and left shall be done, then the test results are recorded, and the larger is the out value of the vehicle. 5