Internally Cooled Engine Valve Roll Forming for Larger Coolant Cavities

Solution Overview

Problem

There is a need for inexpensive and rapid manufacturing of internally cooled valves for internal combustion engines that improve cooling properties and maintain reliability at high exhaust gas temperatures, while reducing the number of components and joints for stability and cost reasons.

Innovation Solution

A method and device for manufacturing internally cooled intake or exhaust valves using roll forming techniques, which involve forming a workpiece with a stem and cylindrical hole to create a coolant cavity, and shaping the valve stem and head using rollers, potentially with heated workpieces and hyperboloid rollers to achieve maximum cavity size and improved heat transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional machining processes are used to manufacture internally cooled valves, then manufacturing precision can be achieved, but production cost increases and productivity decreases

Engineering Contradiction:

Improvevalve manufacturing precisionVSAvoidvalve production rate

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The patent replaces traditional mechanical machining processes (turning, boring, milling) with a roll forming process that uses controlled plastic deformation to shape the valve body and create the coolant cavity. This substitution of the manufacturing system achieves both high precision and high productivity by forming the valve in a single continuous operation rather than through multiple discrete machining steps.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The roll forming process performs preliminary shaping of the valve body and coolant cavity during the main forming operation itself, rather than requiring separate preliminary operations followed by final machining. The cavity is created directly during rolling through controlled material flow and roller geometry, eliminating subsequent boring or drilling operations.

Inventive Principle:

Principle #10Preliminary action

2Manufacturing precision

If traditional machining processes are used to manufacture internally cooled valves, then manufacturing precision can be achieved, but manufacturing cost increases

Engineering Contradiction:

Improvevalve manufacturing precisionVSAvoidmanufacturing cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent replaces traditional mechanical machining processes (turning, boring, milling) with a roll forming process that uses controlled plastic deformation to shape the valve body and create the coolant cavity. This substitution of the manufacturing system achieves both high precision and high productivity by forming the valve in a single continuous operation rather than through multiple discrete machining steps.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent combines multiple manufacturing operations (shaping the valve body, creating the coolant cavity, and forming the valve stem) into a single integrated roll forming process. This merging of operations eliminates the need for separate machining steps, reducing both time and cost while maintaining precision through the continuous controlled deformation process.

Inventive Principle:

Principle #5Merging (Combining)

3Temperature

If the coolant cavity volume is increased to improve cooling properties, then thermal performance improves, but the number of components and joints increases

Engineering Contradiction:

Improvecooling performanceVSAvoidnumber of components and joints

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The patent integrates the coolant cavity directly into the valve body through the roll forming process, creating a monolithic structure where the cooling channels are formed as integral parts of the valve itself. This eliminates the need for separate cooling jackets, inserts, or attached components, thereby improving cooling performance through increased cavity volume while maintaining component simplicity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent utilizes controlled plastic deformation during roll forming to create large-volume coolant cavities within the valve body structure. By changing the material state through controlled heating and deformation, the process can form complex three-dimensional cooling channels that would be difficult or impossible to achieve with traditional machining, maximizing cavity volume without adding components.

Inventive Principle:

Principle #35Parameter changes

4Ease of manufacture

If roll forming is used to reduce manufacturing cost and increase productivity, then ease of manufacture improves, but manufacturing precision may deteriorate

Engineering Contradiction:

Improvemanufacturing cost and productivityVSAvoidvalve dimensional accuracy

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent employs controlled heating of the workpiece during roll forming to reduce material flow resistance and enable more precise dimensional control. By optimizing temperature parameters during the forming process, the material becomes more formable while maintaining tight tolerances on critical dimensions such as cavity volume, wall thickness, and valve stem geometry.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces traditional mechanical machining processes (turning, boring, milling) with a roll forming process that uses controlled plastic deformation to shape the valve body and create the coolant cavity. This substitution of the manufacturing system achieves both high precision and high productivity by forming the valve in a single continuous operation rather than through multiple discrete machining steps.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method enables the production of valves with enhanced cooling capabilities, reduced mechanical stress, and fewer components, resulting in improved thermal performance and cost-effectiveness.

Implementation Method 1

at least one of the rollers has a surface structure which causes the material of the workpiece to be transported in the axial direction

Methodology Applied

Scientific EffectFriction: Friction

Implementation Method 2

forming a workpiece or semi-finished product, or semi-finished product or semi-finished product

Methodology Applied

Scientific EffectPlasticity: Plasticity

Implementation Method 3

potentially with heated workpieces and hyperboloid rollers

Methodology Applied

Scientific EffectHeating: Heating

Data Source

PatentEP3368232B1Method and device for the production of an internally cooled valve for internal combustion engines

Publication Date: 2022.01.12 FEDERAL MOGUL VALVETRAIN GMBH

Figure 1A
Figure 1B
Figure 1C~1D

AI summary

The invention relates to a method and a device for producing an internally cooled inlet or outlet valve (4) for internal combustion engines, as well as the valve produced using the method or the device. The method comprises providing a work piece comprising a cylindrical shaft and a cylindrical hole running from a valve shaft end in the axial direction. The method also comprises deforming the valve shaft end via form rolling the cylindrical shaft to a smaller diameter, wherein a diameter of the cylindrical hole is reduced wherein the cylindrical hole remains intact. The method further comprises deforming the section of the work piece connected to the valve shaft to form a valve head via form rolling.