A combined heat-insulating piston independent piston ring support body structure

Abstract

The invention provides an independent piston ring support structure of a combined heat insulation piston. The structure includes a piston steel head and a piston body, a metal heat insulation pad is arranged between the piston steel head and the piston body, the piston steel head, the metal heat insulation pad and the piston body are provided with bolt holes used for fastening bolts, the piston steel head, the metal heat insulation pad and the piston body are tightly fixed with the bolts through nuts, after machining, an independent piston ring support is installed on the top of the piston body, and the top of the independent piston ring support is pressed through the metal heat insulation pad. According to the independent piston ring support structure of the combined heat insulation piston, after machining, the independent piston ring support is installed, the precision of positioning of the piston ring support is high, and the requirements of casting and forging of the piston body can be met; the combination surface of the independent piston ring support and the piston body is not easy to crack, and the temperature of a piston ring groove is easy to control.

Description

technical field [0001] The invention belongs to the field of internal combustion engines, and in particular relates to a structure of a combined heat-insulating piston independent piston ring support body. Background technique [0002] At present, four-stroke diesel engines mostly use cast aluminum pistons to reduce the mass of the pistons and reduce the reciprocating inertial force of the pistons. However, the limit temperature that the cast aluminum pistons can withstand is relatively low, about 420°C. As the engine combustion pressure continues to increase , the temperature the piston bears continues to rise, which can easily lead to ablation of the top of the piston. In order to solve the above problems, one method is to install a thermal insulation coating on the top surface of the piston to reduce the heat transfer from the combustion chamber to the piston and reduce the surface temperature of the piston. Cracking, falling off and other problems, the reliability probl...

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Problems solved by technology

The disadvantages of this method are: 1. The position error of the insert ring (including the axial dimension error and radial dimension error along the piston) is relatively large, and the placement of the insert ring during casting and the washing of the insert ring by the aluminum liquid during the casting process will cause The insert ring brings a large position error; second, the insert ring and the aluminum body are cast as one, and the bonding strength of the joint surface is very important. If the bonding strength is insufficient, it will cause cracks between the insert ring and the aluminum body, which will easily cause the aluminum body of the piston The source of cracks with the insert ring will cause the piston or insert to break; 3. Although the ring groove is an important channel for the piston to dissipate heat, if the temperature of the ring groove is too high, it will cause oil coking and the piston ring to be stuck. Therefore, the ring groove should also be strictly controlled. Generally, the temperature of the first ring groove of the piston should be controlled within 260°C. The piston insert is cast into one body with the aluminum body. The supply of coolant during the design and engine operation is very demanding; Fourth, in order to further improve the strength of the piston aluminum alloy, the aluminum body of the piston can be manufactured by forging, and the current integral piston ring support body cannot be used for forging pistons

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