GB13552-92标准（英文版）

National Standard of the Peoples Republic of China GB13552-92 Automotive V-ribbed belts 1. Theme and application scope This standard specifies the classification, technical requirements, test methods, inspection rules, marking, packing, transport and storage of automotive V-ribbed belts (hereinafter shortened as belts). This standard is applicable to V-ribbed belts that are used to transfer the force of automotive gas engine to some accessory machines like cooking fan, dynamotor, water pump, compressor, power steering pump and etc. 2 Product classification 2.1 Marking Belts are classified according to cross sections. This standard only contains PK type, and wedge number is 3 or above. The marking contents of belts are wedge number, type and belt length in order. wedge numbertypeBelt length22 Structure Endless belt with the cross section shown in figure 1Figure 1-name of each part in the structure,1-cover; 2- core; 3-adhesive glue; 4-wedge glue Approved by China State Bureau of Technical Supervision on 06-29-1992 Implemented on 06-01-1993GB 13552-922.3 Materials Adhesive glue and wedge glue is made by corresponding method. The cover uses ninon made of cotton fiber or synthetic fiber, whose longitude and woof shall be equal without any spots or deformation. 2.4 Dimension 2.4.1 Dimension of sections See table 1 and figure 2 for dimension of sections Table 1 section dimension of beltsnamesymboldimensionwedge anglea()40pitchp35.6belt widthb35.6nbelt heightH6（reference number）wedge heightC3（reference number）radius of wedge bottomr025note: n represents wedge numberFigure 2-belt section2.4.2 Effective length of belts Effective length of belts shall be measured according to clause 4.1. Its limit deviation is shown as table 2. Table 2-limit deviation of belt lengthbet lengthlimit deviation10 0005.010 0001 2006.01 2001 5008.01 5002 00010.02 00012.03 Technical requirements 3.1 Dimension Section dimension and effective length of belts and limit deviation of the length shall follow the specifications in figure 2, table 1 and table 2 correspondingly. 3.2 Appearance quality The appearance of belts shall have no objections, e.g. distortion, deformation, clot, faults, pinprick, eyewinker and etc. 3.3 Fatigue life The fatigue life of belts is measured according to clause 4.3 and the test result shall not be smaller than 100h. The fatigue life refers the total operation time of belts till broken under certain loading.3.4 TensilityTable 3 specifies the tensile strength and elongation percentage of belts. Table 3-tensilitywedge numbertensile strengthelongation percentage of reference loadKN%reference load kN32.430.7643.231.0054.031.2564.831.5075.631.7580.830.25nNote: n refers to wedge number. 3.5 High temperature resistance Belts shall have not cracks after high temperature resistant test.3.6 Low temperature resistantBelts shall have not cracks after low temperature resistant test. 4 Test method 4.1 Measurement of belt length Place the belt on the length measuring machine shown as figure 3, load 100nN (n is wedge number) on the belt, turn the belt for 2-3 rounds so as to get the maximum value and minimum value of center distance between two belt wheels, and then calculate the belt length according to following formula. See figure 4 and table 4 for dimension of belt wheels of belt measuring machine. Measuring force FFigure 3-sample of length measuring machineWhere:L=belt length, mmC = center distance, mm;Cmax = maximum center distance, mm;Cmin = minimum center distance Figure 4-dimension of belt wheel for length measuringTable 4-dimension of belt wheel for length measuring mmsymbolnominal valuelimit deviationsymbolnominal valuelimit deviationD96.480.18H(reference number)3.45-()400.25r(t)0.25+0.15p3.550.05rb(reference number)0.5-d2.500.01Do(reference number)95.5-Note: when the wedge number is greater or equal to 7, the cumulated deviation of p shall not be greater than +0.30. 4.2 Appearance visual inspection 4.3 Fatigue life test4.3.1 Test environment and equipment The test temperature shall be within 20 10C. The test equipment is shown as figure 5, while the dimension of its belt wheels is shown in figure 6 and table 5. Except for divers, other belt wheels could be adjusted. tension Figure 5-sample of fatigue testerdirection of rotationdrivertension pulleyFollowerFigure 6-dimension of belt wheelTable 5-dimension of belt wheelsymboldriver dimension and follower dimensiontension pulley dimensionnominal valuelimit deviationnominal valuelimit deviationDo1200.2555.00.25()401401p3.560.053.560.05H(reference value )3.45-3.45-r(t)0.25+0.150.25+0.15rb0.5-0.5-4.3.2 Test belt The length of test belt shall be between 850mm to 1000mm. It could also be replaced by the belt with different length but with same structure and material. 4.3.3 Test method for fatigue life Place the belt on the testing machine shown as figure 5. Figure 6, table 5 and table 6 shows the diameter of belt wheel, rotating speed of the driver, load of the belt and tension. Operate the belt for 5 minutes under same tension. During these 5 minutes, do not lock the center of tension pulley. Stop the machine for a short while, fix the center of tension pulley to the position half of distance limit, and then open the machine again. Stop the machine again when the slip reaches 4%, meanwhile, loose the center position of tension pulley, and fix it again when the tension recovers. During the test, it is allowed to adjust the tension once only. The time for the slip to reach 4% or the total time till the belt breaks is the fatigue life of the belt (5 minutes exclusive). The temperature around the testing machine shall be within 32 to 45 C.Table 6-rotate speed of drivers, load of belt and tensionwedge numberrotate speed of drivers r/minpower of followers kWtension N（kgf）34 8008685(70)44 8009.5813(80)54 80011935(95)64 80012.51 060(108)74 800141 185(121)Note: when wedge number shall be equal to or greater than 8, it is under the negotiation of two interested parties. 4.4 Tensile test Tensile test shall be carried out according to methods as follows. Cut 250mm-long test piece from the sample under room temperature 23+2C, draw two lines with 100mm distance in the middle of the test piece, put the test piece on tensile testing machine and then pull it at the speed of 2550mm per minute. When the tension is equal to loads specified in table 3, measure the elongation percentage between two lines on the test piece, then continue to pull the piece till it breaks so as to measure the maximum tension and also calculate the tensile strength. Take the average of three measured values as the rest result. 4.5 High temperature resistance testCut a test piece from the sample as shown in 4.4. After placing it under the temperature 100+1C for 70+2 hours, take it out and put it in the place under the room temperature for 2 hours. Then bend it around the surface of a cylinder whose diameter is 40mm (the side with the wedge touches the cylinder) to see whether there is any crack on the surface of the test piece.4.6 Low temperature resistance testAfter putting the test piece after high temperature resistance test under the temperature -30+1C for 70+8 hours, take it out and place it in the place under the room temperature for 2 hours. Then bend it around the surface of a cylinder whose diameter is 40mm (the side with the wedge touches the cylinder) to see whether there is any crack on the surface of the test piece. 5 Inspection rules5.1 Belts shall be inspected by quality inspection department of manufacturers. They shall not leave the factory without the approval certificate. 5.2 Each belt shall take appearance quality test according to sub-clause 3 and 4. 5.3 If each batch is less than 1000, it is necessary to take out one at random to take dimension and tension test. If monthly-produced belts are less than 1000, then the test is carried out once a month. 5.4 If each batch is less than 3000, it is necessary to take out enough belts for high and low temperature resistance tests. If quarterly-produced belts are less than 3000, the test shall be carried out once a quarter. 5.5 If each batch is less than 5000, it is necessary to take out one belt from each batch for fatigue life test. If the quantity of belts produced in half a year is less than 5000, then the test shall be carried out once in half a year.5.6 If any test in 5.3, 5.4 or 5.6 fails, it is necessary to retest the disqualified items by taking out doubled test samples from this batch. If it still fails, then this batch of products or products produced during this time period are regarded as disqualified ones. 6 Marking, packing, storage and transport 6.1 Each V-ribbed belt shall have clear symbols as follow that could not be washed away by water: a. Marking;b. Manufacturer and label;c. Production date or code6.2 Each V-ribbed belt shall be packed by the paper or plastic film. Every 50 or 100 belts shall be package by cases. Each packing case shall mark the specification and quantity of be