Internal combustion engines - Piston rings - Part 12: Half keystone rings made of steel
1 Scope
This document specifies the essential dimensional features of half keystone piston rings made of steel, types HK, HKB and HKBA (hereinafter referred to as "half keystone rings made of steel").
It applies to half keystone rings made of steel used in reciprocating internal combustion piston engines having cylinder diameters from 50 mm up to, and including, 160 mm.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 6621-4, Internal combustion engines - Piston rings - Part 4: General specifications
Note: GB/T 1149.1-2008, Internal combustion engines - Piston rings - Part 1: General specifications (ISO 6621-4:2003, IDT )
3 Terms and definitions
There are no terms or definitions that need to be defined in this document.
4 Overview
The half keystone ring types are specified in Tables 1 and 2 and Figures 1, 2 and 3. Their common features and the dimensions of those features are specified in Tables 3 to 7 and Figures 4 to 10. Table 7 gives the force factors for the different ring types, while Table 8 gives the dimensions and forces of half keystone rings, and Table 9 gives the dimensions and elasticity..
5 Ring types and designation examples
Note: For the angle of half keystone rings, the same definition and measurement apply as for keystone rings (see ISO 6621-2).
5.1 Type HK - Straight faced half keystone ring 7°
5.1.1 General features
Figure 1 shows the general features of piston ring type HK.
See Table 9 for dimensions and forces.
h3 values are calculated based on Annex A.
