The working conditions of the engine cylinder set are at a higher temperature, semi-drying state, and is strongly friction-by the piston ring, therefore, the surface of the cylinder line should have a high hardness; the cylinder line is also affected by the alternating load, so it is hard The surface of the surface should be tough, and the widespread variable frequency induction heating equipment factory has also analyzed in the conventional heat treatment process. In the past, the cylindernet was used as an overall quenching process, and later used induction quenching process. The advantages of adopting induction quenchings are: 1 It can be produced on the pipeline, and the productivity is much higher than the overall quenching; 2 energy saving; 3 hardened layer depth can be selected as needed.
The cylinder line is generally manufactured with pearlite gray cast iron, and its cast structure has a stricter requirement. The hardness of the casting is 170 ~ 241HBW. The hardness of the cylinder liner is generally required to be ≥43 hrc. The hardening layer is 1.5 ~ 2.5mm, and the hardening zone is allowed to have a transition zone at both ends, such as the upper end ≤15mm, the lower end ≤ 25 mm, and the like.
1. Induction quenching according to the hardening layer depth, can be used for ultra-audio or intermediate frequency 8 kHz; the power is determined according to the diameter of the cylinder, such as a cylinder jacket having an inner diameter of 125 mm, a height of 292 mm, optionally 160 ~ 200 kW power. When a dual-station alternately working, the productivity can reach 90 pieces / h. When scanning quenching, the heating temperature and time have a great influence on the consequences of the quenching. The scanning speed used in the production is 6 ~ 7mm / s, that is, the heating time of each mass point is about 3s (the effective ring width is 20mm), the heating temperature is 900 At about ° C, better quenching results can be obtained (fine needle martensite and hit tissue).
2. The tempering of the tempering cylinder line is used to use a power frequency backfire. The three-position power frequency is turned back to the fire. 3 cylinder blocks can be made back to the fire. When the rotating workbench is turned back to the fire (the temper temperature is generally 200 ~ 220 ° C, the tempering time is generally Around 40S), the three vacancy on the other column can be installed on the cylinder set. When the cylinder set completes the tempering, the power frequency back fire coil has risen, the workbench is turned 180 °, the coil drops, and the second column of 3 cylinder sets are started. The co-cylinder is sleeves back to the fire sensor built-in silicon steel core, and the coil is made of a multi-layer, multi-flat copper wire. The productivity exceeds the productivity of 90 pieces / h in the quenching machine, which can be used to support the production combination. Arranged on the production line.