Rotated Cylinder Head Bolt Arrangement for Combustion Engine Rigidity

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Solution Overview

Problem

Internal combustion engines with high cylinder pressures face challenges in longevity and durability due to the rigidity requirements of cylinder head structures, particularly with rotated valve patterns, which limit flexibility and increase complexity in valve trains and water jacket design, leading to larger engine dimensions and higher costs.

Innovation Solution

The solution involves unifying outlet sub-channels outside the cylinder bore diameter to form a common outlet channel and dividing inlet sub-channels within the bore diameter, with a triangle area between valve axes and port connection points occupying 5-15% of the bore area, and rotating the cylinder head bolt arrangement to enhance rigidity and flexibility, allowing for a compact and simple valve train design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a rotated valve pattern is used in internal combustion engines with high cylinder pressures, then flexibility in component positioning is improved, but the rigidity of the cylinder head structure deteriorates

Engineering Contradiction:

Improveflexibility in component positioningVSAvoidrigidity of cylinder head structure

Core Design Contradiction:

Adaptability or versatilityVSStrength

Solution Approach 1:

The patent applies asymmetry by rotating the valve pattern at a specific angle (e.g., 45 degrees) relative to the cylinder axis, creating an asymmetric arrangement of intake and exhaust valves. This asymmetric configuration allows optimization of component positioning flexibility while the specific rotation angle is chosen to maintain adequate structural rigidity of the cylinder head under high pressure conditions

Inventive Principle:

Principle #4Asymmetry

2Ease of manufacture

If outlet sub-channels are routed separately within the cylinder bore diameter, then manufacturing simplicity is improved, but the area available for structural support is reduced

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidarea for structural support

Core Design Contradiction:

Ease of manufactureVSArea of stationary object

Solution Approach 1:

The patent merges the outlet sub-channels by routing them outside the cylinder bore diameter and combining them into a common outlet channel. This consolidation increases the area available for structural support within the cylinder bore while maintaining manufacturing simplicity through a unified channel design that can be integrated into the cylinder head casting process

Inventive Principle:

Principle #5Merging (Combining)

3Adaptability or versatility

If the valve train is designed to accommodate rotated valve patterns and separate sub-channels, then adaptability is improved, but device complexity increases

Engineering Contradiction:

Improveadaptability to high pressure loadsVSAvoidcomplexity of valve train and water jacket

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by optimizing specific regions of the cylinder head: the outlet sub-channels are routed outside the bore diameter in a specific zone to avoid interfering with the valve train, while the inlet sub-channels are arranged within the bore with optimized spacing. The water jacket is designed with enhanced cooling passages in critical areas such as the seat ring spaces, providing targeted cooling without requiring a completely complex water jacket design throughout

Inventive Principle:

Principle #3Local quality

4Strength

If cylinder head bolts are positioned to accommodate the valve pattern, then structural integrity is improved, but engine dimensions increase

Engineering Contradiction:

Improvestructural integrity of cylinder headVSAvoidengine dimensions

Core Design Contradiction:

StrengthVSLength of stationary object

Solution Approach 1:

The patent utilizes another dimension by routing the outlet sub-channels outside the cylinder bore diameter rather than confining all channels within the bore. This spatial reorganization allows the cylinder head bolts to be positioned optimally for structural integrity without increasing engine dimensions, as the channel routing uses the available space in the radial direction outside the bore rather than requiring additional axial length

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP3268597B1Internal combustion engine having at least one cylinder

Publication Date: 2020.11.04 AVL LIST GMBH

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AI summary

The invention relates to an internal combustion engine (2) having at least one cylinder (1, 1', 1'') with at least one cylinder head (11, 11', 11'') which is connected via a plurality of cylinder head bolts (19, 20, 21, 22, 19', 20', 21', 22', 19'', 20'', 21'', 22'') per cylinder (1, 1', 1'') to a cylinder housing, wherein two inlet valves (3, 4) and two outlet valves (5, 6) are arranged per cylinder (1, 1', 1''), which valves have a rotated valve pattern in relation to an engine longitudinal plane (2a), wherein the bolt axes (19a, 20a, 21a, 22a) of all cylinder head bolts (19, 20, 21, 22; 19', 20', 21', 22'; 19'', 20'', 21'', 22'') which are assigned to one cylinder (1, 1', 1'') define with one another cylinder head bolt planes (24a, 24b, 24c, 24d, 24e, 24f) which are arranged parallel to the cylinder axis (1a). In order to make high flexibility in the arrangement of components possible, it is provided that all cylinder head bolt planes (24a, 24b, 24c, 24d, 24e, 24f) which are assigned to one cylinder (1, 1', 1'') are inclined both with respect to the engine longitudinal plane (2a) and with respect to an engine transverse plane (2b, 2c) which lies perpendicularly on the engine longitudinal plane (2a).