Evaluation of tire wear, using an electrical fork lifter, on industrial resilient tires Trelleborg Elite XP LOC and competitor Continental SC20 SIT.

Transcription

1 performed on March 2011 by for Italia SpA Via Tiburtina, 143, Villa Adriana, IT-00010, Roma Report No Evaluation of tire wear, using an electrical fork lifter, on industrial resilient tires Trelleborg Elite XP LOC and competitor Continental SC20 SIT. Tires: 23x10-12/8.0 mounted on front load axle. 18x7-8/4.33 mounted on rear steering axle. Tested Criteria: Tread wear of fork lift truck tires on a test track under heavy duty operating conditions. Date: Our reference: AM-SER Document: Report No.: Date of the Test: March 23 to March 24, 2011 This document consits of 9 Pages. Page 1 of 9 Test Location: ISAM Motor Center of ISTITUTO SPERIMENTALE AUTO E MOTORI S.p.A. Via Morolense, Km 2,600 - Anagni (FR), Italy.

2 Page 2 of 9 1. OBJECTIVE Aim of the project is comparing the tread wear characteristics of industrial tires, specification Trelleborg Elite XP with competitor Continental SC20 under operating conditions. A test procedure using different tires on specified forklift trucks during heavy duty service operation has been built up. 2. SCOPE OF TESTS The test tires and reference tires are run on the identical industrial vehicle (figure 1) and on a defined cyclic route at the test track located in Italy. The route is driven in both cycle directions, clockwise (cw) and counter-clockwise (ccw). Tread depth at the tire tread center and in the tire shoulder and the loss of tread mass of the tires is measured periodically during the test by a tire test engineer of. Figure 1 Loaded forklift at ISAM Motor Center

3 Page 3 of 9 3. TEST LOCATION Test area at ISAM Motor Center of ISTITUTO SPERIMENTALE AUTO E MOTORI S.p.A. Via Morolense, Km 2,600 - Anagni (FR), Italy. 250/60-12/8.0(23x10-12) 4. TEST TIRE POPULATION 4.1. Test Tire - Trelleborg Elite XP LOC Front Axle: 23x10-12/8.0 Tire IDs: XT 0030, Production week 03/ XT 0166, Production week 03/11 Rear Axle: 18x7-8/4.33 Tire IDs: XT 0088, Production week 03/ XT 0090, Production week 03/ Reference Tire - Continental SC20 SIT Front Axle: 250/60-12/8.0 (23x10-12) Tire IDs: , DOT , DOT 4310 Rear Axle: 180/70-8/4.33 (18x7-8) Tire IDs: , DOT , DOT 4110 All tires used for the test were new and bought in the free market. 5. TEST VEHICLE Electrical fork lifter Jungheinrich EFG-V25 (Serial No ), 2500kg load capacity with the following axle load distributions: Front/Rear axle load at maximum load: 6200kg/650kg Front/Rear axle load without load: 2150kg/2200kg.

4 Page 4 of 9 6. TEST PROCEDURES AND EQUIPMENT 6.1. Test Track Pavement: asphalt, grey; flat surface Characteristics: the average macro-texture depth (TD) was measured according to the volumetric method (acc. to ISO10844 Annex A), made on eight different positions evenly spaced along the route of the test track and the average value taken (figures 2, 3). Measured average texture depth result: 1,8 mm. Figure 2&3 Track roughness and temperature measurement 6.2. Test Manoeuvres Operating condition Max. test speed is kept constant and equal for both tire specifications due to limitation of accelerator-pedal travel and adaptation of accelerator-pedal travel to tire circumference. Change of driver after each cycle (20 laps) and additionally change of driving direction (clockwise, counter-clock-wise) Vehicle load Machine weight: 4350 kg Fork lift load: 1730kg plus fastening material.

5 Page 5 of Test Procedure Layout of test path established on the test track: see figures 4 and 5. Figure 4 Test path of ISAM Motor Center Test distance / no. of cycles / test time 6 turns, each 20 cycles (laps of test course), length per turn (20 laps): 6400 ±50m; Overall distance: 38,3 km. Test time each cycle (20 laps): 30 ±1min; total operating time: 180 min. Figure 5 Forklift truck running on the test track

6 Page 6 of Measuring Methods and Equipment Ambient conditions Ambient temperature measuring device: Kobold TD 1200 (Serial No ) Surface temperature measuring device: Infrared HIOKI (Serial No ) Tread wear Digital balance TCS (Serial No ) Tread depth: Mitutoyo ID-U 1025 (Serial No ) Distance and time: fifth wheel on the fork lift truck and standard stop watch (figure 6, 7). Figure 6&7 Measuring equipment 7. AMBIENT CONDITIONS Trelleborg Elite XP LOC at beginning 11:26h at end - Air temperature: 18 C 17 C - Ground temperature: 27 C 33 C Continental SC20 SIT at beginning 11:05h at end - Air temperature: 19 C 20 C - Ground temperature: 28,5 C 36 C.

7 Page 7 of 9 8. TEST EXECUTION Each tire is weighted on the balance machine. Tread depth in 16 different spots at center and shoulder level is measured before the tire is fitted on the forklift. The forklift is driven to the track for a distance of 200m to let the tires run in. The ground and tire temperatures are measured to have comparable conditions. After that the forklift truck runs for 120 laps. Figure 8 Temperature and tread depth measurement At the end of every 20 laps the temperatures are measured (figure 8), the direction of the track and the driver are changed in order to minimize the influence of the different driving styles. When the forklift reaches half distance 60 laps, in addition to the above, the measurement of tread depth at shoulder and center spots is carried out. After 120 laps the tires are taken off the forklift and weighted (figure 9, 10). Then tires cool down overnight before the tread depth is measured and weight of rims is analyzed. Figure 9&10 Elite XP and Conti SC20 weight measurement

8 Page 8 of 9 9. TEST RESULTS Tread wear of industrial tires Trelleborg Elite XP LOC and Continental SC20 SIT in sizes 23x10-12/8.00 and 18x7-8/4.33 during heavy duty operation with a fork lift truck is measured in two ways: 1. Periodical tread depth measurement during the test Start [mm] 50% [mm] Finish [mm] Rel. [%] Start-50% Tire Shoulder Center Shoulder Center Shoulder Center Shoulder Center Elite XP 23x10-12/8.0 18,7 12,5 17,7 11,0 16,8 9, Conti SC20 23x10-12/8.0 20,7 19,3 19,5 16,1 * * Elite XP 18x7-8/ ,9 11,4 15,5 10,7 15,3 10, Conti SC20 18x7-8/ ,5 16,4 16,8 15,4 * * *After the test the Continental SC20 SIT showed uneven wear on the shoulder, thus the tread depth was not measurable see figure 11. During the test procedure the tread wear of the Continental SC20 SIT is 20% (shoulder) / 113% (center) higher than tread wear of the Trelleborg Elite XP LOC on the front axle and 75% (shoulder) / 43% (center) higher on the rear axle (measured at 50% of the test distance). Figure 11 Elite XP vs. SC20 tread at the end of the test 2. Measurement of weight loss of the single tires before and after the test. Tire Start [Kg] Finish [Kg] Weight Loss [g] Relative [%] Elite XP 23x10-12/8.0 51,90 51, Conti SC20 23x10-12/8.0 45,05 43, Elite XP 18x7-8/ ,80 21, Conti SC20 18x7-8/ ,90 19, During the test procedure the loss of tread mass of the Continental SC20 SIT is 50% higher than tread mass loss of the Trelleborg Elite XP LOC on the front axle and 40% higher on the rear axle. The results of weight loss in kg and relative % of tread wear consumption are shown in figures 12 and 13.

9 Page 9 of 9 Loss of Tread Mass (g) Trelleborg Continental Front Axle Rear Axle Figure 12 Results of tire mass loss measurement (absolute) Loss of Tread Mass (relative %) Trelleborg Continental Front Axle Rear Axle Figure 13 Results of tire mass loss measurement (related to Trelleborg) This test report consists of 9 pages., 31. March 2011 Safety and Electronics Tires and Wheels Lars Netsch (Project Manager) Florian Speyerer (Test Engineer)