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Combined thermal insulation bolt connection structure

A technology for connecting structures and piston bolts, applied in the directions of pistons, engine components, machines/engines, etc., can solve problems such as increased design, processing difficulty, increased tensile load, and aluminum body cracking, etc., to avoid thermal load increase, The effect of reducing the contact stress and increasing the contact area

Inactive Publication Date: 2017-08-29
CHINA NORTH ENGINE INST TIANJIN
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[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 low, about 420 degrees. As the combustion pressure of the engine continues to increase , the temperature of the piston continues to rise, and the cast aluminum piston can no longer withstand such a high temperature, which can easily lead to piston ablation
[0003] 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 problem is still difficult to solve, so it is not recommended; another method is to use the combined piston with steel top and aluminum skirt. The steel top can withstand high temperature and is not easy to cause piston ablation, but the steel The temperature transmitted from the top to the aluminum body is relatively high, and the cooling oil channel must be used for cooling, which increases the difficulty of design and processing
In addition, the piston with such a combined structure needs to be connected by bolts. When the piston is heated and expanded, the tensile load on the piston increases sharply, resulting in a very large contact pressure between the bolt and the aluminum body, and it is easy to cause the aluminum body to be in contact with the bolt head. location cracking

Method used

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Embodiment Construction

[0026] It should be noted that, in the case of no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0027] The present invention will be described in detail below with reference to the accompanying drawings and examples.

[0028] A combined insulation piston bolt connection structure, such as Figures 1 to 5 As shown, it includes piston steel top 1, metal heat insulation pad 2, insert ring 3, elastic combined gasket 4, bolt 5 and aluminum body 6;

[0029] The metal heat insulating pad 2 is arranged between the contact surface of the piston steel top 1 and the aluminum body 6 , and the metal heat insulating pad 2 is used to isolate the heat conducted from the piston steel top 1 to the aluminum body 6 .

[0030] The piston steel top 1 is provided with bolt holes for bolt fastening, the metal heat insulating pad 2 and the aluminum body 6 are provided with through holes for passing through the bolts, the pist...

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Abstract

The invention provides a combined thermal insulation bolt connection structure. The combined thermal insulation bolt connection structure comprises a piston steel crown, a metal thermal insulation pad, elastic combined gaskets, bolts and an aluminum body; the metal thermal insulation pad is arranged between the piston steel crown and the contact surface of the aluminum body, the piston steel crown is provided with bolt holes for bolt fastening, the metal thermal insulation pad and the aluminum body are provided with through holes used for allowing the bolts to penetrate through, the piston steel crown, the metal thermal insulation pad and the aluminum body are fastened together through multiple bolts, and the elastic combined gaskets are arranged between the heads of the bolts and the aluminum body. The combined thermal insulation bolt connection structure has the following advantages that the metal thermal insulation pad is arranged between the piston steel crown and the aluminum body, therefore, heat is partially isolated through the thermal insulation pad, and the temperature of the aluminum body is controlled within the reasonable range; the elastic combined gaskets are adopted between the bolts and the contact surface of the aluminum body, therefore, part of deformation can be compensated when the piston is heated to be expanded or cooled, and the tensile loads of the bolts are reduced; the contact stress of the aluminum body bearing surface can be reduced, and then aluminum body cracking is prevented.

Description

technical field [0001] The invention belongs to the technical field of engine pistons, and in particular relates to a bolt connection structure of a combined heat-insulating piston. 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 low, about 420 degrees. As the combustion pressure of the engine continues to increase , the temperature of the piston continues to rise, and the cast aluminum piston can no longer withstand such a high temperature, which can easily lead to piston ablation. [0003] 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 o...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): F02F3/00F02F3/02
CPCF02F3/0023F02F3/0084F02F3/02
Inventor 张利敏王延荣许春光刘玉婷张晓静
Owner CHINA NORTH ENGINE INST TIANJIN
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