Steering Shaft Cold Forging for Deep-Hole Spline Integration
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Solution Overview
Problem
Steering shafts in automotive systems face challenges with increased production costs due to the use of multiple components and prolonged production times, especially when forming deep holes, which can lead to reduced yield and accuracy issues.
Innovation Solution
A method for manufacturing a steering shaft using cold forging techniques to form deep holes and spline grooves, reducing the number of components and processes, and integrating the shaft parts to enhance torque transmission reliability while minimizing weight and production costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple shaft components are used and assembled by press-fitting, then torque transmission reliability is improved, but production cost increases and production time is prolonged
Solution Approach 1:
The patent merges multiple shaft components (first shaft, second shaft, third shaft) into a single integrated shaft structure. The intermediate shaft integrates the functions of multiple separate shafts that would otherwise require press-fitting assembly, thereby reducing the number of components and assembly operations while maintaining torque transmission reliability through the integrated design.
2Ease of manufacture
If deep holes are formed by conventional drilling or piercing, then hole formation is achieved, but production time is prolonged and manufacturing cost increases
Solution Approach 1:
The patent performs preliminary action by forming the deep holes (first hole part, second hole part, third hole part) as integral features of the shaft structure during the initial forging or forming process, rather than creating them separately through drilling or piercing operations. This preliminary integration of hole formation into the main manufacturing process significantly reduces subsequent processing time and cost.
3Weight of moving object
If shaft weight is reduced by hollowing out the structure, then weight reduction is achieved, but structural strength may be compromised
Solution Approach 1:
The patent applies local quality by strategically positioning and dimensioning the hollow portions (first hole part, second hole part, third hole part) within the shaft structure. The holes are located in specific regions where they reduce weight while the overall shaft geometry and material distribution are optimized to maintain sufficient structural strength for torque transmission requirements.
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 effectively reduces the weight and improves torque transmission reliability at lower costs by integrating shaft parts and using cold forging to efficiently form deep holes and spline grooves, thereby simplifying the manufacturing process and enhancing the structural integrity of the steering shaft.
Implementation Method 1
A method for manufacturing a steering shaft using cold forging techniques to form deep holes and spline grooves
Implementation Method 2
The blank is pressed into a die to perform drawing in the radial direction
Data Source
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AI summary
To provide a method of manufacturing a shaft for a steering device, the shaft including a spline shaft part to be coupled with an input shaft, a stopper part to be coupled with an output shaft, and an intermediate shaft part that couples the spline shaft part with the stopper part. The method includes: a step of forming a hole part recessed in an axial direction from one end of a pillar-shaped material by forging; and a step of pressing the material in which the hole part has been formed into a die to perform drawing in a radial direction on a portion of the material at which the spline shaft part and the intermediate shaft part are formed, and prolonging a length along the axial direction of the hole part at the same time by forging.