This standard specifies the technical requirements, inspection rules, marking, packaging and storage of cylinder commutators for starters used in agricultural tractors and internal combustion engines. JB/T 6708-1993 Technical conditions for starter commutators for tractors and internal combustion engines JB/T6708-1993 Standard download decompression password: www.bzxz.net

Machinery Industry Standard of the People's Republic of China
JB/T 6708-93
Technical Conditions for Commutators of Starters for Tractors and Internal Combustion Engines
Published on July 29, 1993
Ministry of Machinery Industry of the People's Republic of China
Implementation on January 1, 1994
JB/T6708-93
3.17 Commutators shall not be deformed or loosened after being subjected to low-temperature test, high-temperature test and temperature change test. For plastic commutators, the outer circle runout shall not exceed 0.09mm and the inter-segment runout shall not exceed 0.015mm based on the center line of the shaft hole. 3.18 After the plastic commutator is tested at ultra-high temperature (200 ± 5℃) for 30 minutes, the outer circle runout should be no more than 0.09mm and the inter-segment runout should be no more than 0.015mm based on the center line of the shaft hole. 3.19 The shaft hole of the plastic commutator adopts steel parts (bushings) and should withstand axial static pressure of 20kN. The bushings should not be axially loose. Special products shall be specified separately. bZxz.net
3.20 The commutator should be able to withstand the wet heat test. After the test, the commutator should comply with the provisions of Articles 3.12 and 3.13, and the plastic commutator should comply with the provisions of Articles 3.12 and 3.14.
3.21 The durability test of the commutator should comply with the durability test provisions of the matching starter. 3.22 The wet heat type commutator shall be able to withstand the salt spray test and mildew test requirements specified in Articles 3.14 and 3.18 of JB/T6697. 3.23 If the user complies with the installation, use, maintenance and storage specified in the product technical documents, the manufacturer shall repair or replace the product for free within 12 months from the date of delivery if the product cannot work normally due to product quality. 4 Test method
During the test, the voltage meter shall not be lower than level 0.5, and other measuring instruments shall not be lower than level 1.0. 4.1
The appearance quality of the commutator is measured by visual inspection.
The limit deviation of the inner hole diameter is measured by a standard plug gauge. The radial circle runout is measured by a micrometer.
The outer circle runout is measured by a micrometer.
The deflection of the commutator clip to the axis is measured by an inclined plate inspection instrument. The roughness of the shaft hole is measured by a special measuring tool,
4.8 The runout between adjacent pieces is measured by a micrometer. 4.9 Withstand voltage test
Between commutator segments: Place the commutator on the inter-segment tester, make sure that the adjacent commutator segments are in good contact with the electrodes, then apply the specified test voltage to make it rotate, and keep the power on between the segments for 1 second. 4.9.2 Between commutator segments and shaft: Insert the measuring mandrel into the shaft hole, clamp all commutator segments on the withstand voltage test bench, and apply the test voltage to the commutator starting from no more than half of the specified value, gradually increase to the full value of the test voltage, maintain for 1 second (1 minute for plastic commutator), then quickly reduce the voltage to less than half the value, and then disconnect the power supply. 4.10 Insulation resistance measurement: Use a 500V megohmmeter to measure the insulation resistance between the commutator segment and the mandrel at room temperature. 4.11 Overspeed test at ambient temperature: Install the commutator on the overspeed test machine and run it at the specified speed at ambient temperature for 1 minute. 2 Hot overspeed test: Install the plastic commutator on an overspeed test machine with a constant temperature device, gradually and evenly raise the temperature to 150 ± 4. 12
2℃, preheat for 30 minutes, then overspeed at the specified speed, and test for 2 minutes. 4.13 Low temperature test, high temperature test and temperature change test shall be carried out in accordance with the provisions of Articles 4.8 to 4.10 of JB/T6697. 4.14 Ultra-high temperature test: The plastic commutator should be directly placed in a high temperature box that has been raised to 200 ± 5℃ at an ambient temperature of 23 ± 5℃, and kept at high temperature for 30 minutes.
5 Axial static pressure is carried out on a special test bench. 4.15
Wet heat test: Install the commutator simulation device on the starter and conduct the test according to the starter wet heat test requirements. Durability test: It should be installed on the starter and evaluated together with the starter. 4.17
The salt spray test and mildew test of the wet heat type commutator shall be carried out in accordance with the provisions of Articles 4.12 and 4.15 of JB/T6697. 5 Inspection rules
The factory inspection shall be carried out in accordance with Articles 3.6 to 3.13. Only qualified products can be shipped out of the factory and accompanied by a product certificate. 5.1
Users can accept according to the provisions of GB2828. The acceptance items and qualified quality levels are shown in Table 1. 5.2
a. General inspection level: I;
Marking, packaging, transportation and storage
JB/T6708-93
Commutators should be packaged according to different specifications, and the model, specification and manufacturer name should be attached. The words and logos on the outer wall of the commutator packaging box: product model, name, quantity, gross weight, volume, handle with care, moisture-proof and other words or marks. The packaging of the commutator should be guaranteed to prevent collision damage during transportation. The commutator should be stored in a warehouse with dry air and no harmful gas intrusion, and should not be exposed to corrosive substances such as acids and alkalis and organic solvents. Additional instructions:
This standard was proposed by the National Technical Committee for Tractor Standardization. This standard is under the jurisdiction of the Luoyang Tractor Research Institute of the Ministry of Machinery Industry. This standard was drafted by Shanghai Automotive Electric Factory. The main drafter of this standard is He Zhonghui.
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