Constant Velocity Drive Shaft Cold Forging With Burr-Free One-Step Forming
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for manufacturing drive shafts, particularly constant velocity drive shafts, face challenges such as burr formation, inefficient processing, and increased manufacturing costs, especially when dealing with complex structures that require multiple cold forging processes.
Innovation Solution
A method using full enclosed die cold forging with a metal mold pair, involving annealing and cooling steps to create a hardness difference in the molding material, allowing for one-step molding of multiple large-diameter parts, thereby preventing burr formation and reducing manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If cold forging is performed in multiple processes for complicated structures, then the drive shaft can be manufactured, but manufacturing cost increases
Solution Approach 1:
The patent combines multiple cold forging processes into a single integrated process by positioning multiple dies (first die, second die, third die) within one press operation. The molding material is subjected to simultaneous pressing from multiple directions in one step, forming multiple large-diameter parts (first, second, and third large-diameter parts) concurrently, thereby eliminating the need for sequential multi-process operations and reducing manufacturing cost.
Solution Approach 2:
The patent segments the molding material into multiple regions that will form different large-diameter parts simultaneously. By applying localized pressing forces to different segments of the material through separate dies positioned at different locations, the complex structure with multiple large-diameter sections is formed in a single operation rather than requiring multiple separate forging steps.
2Productivity
If conventional cold forging is used, then manufacturing efficiency is maintained, but burr occurs in processed portion requiring additional removal process
Solution Approach 1:
Instead of forming the drive shaft from the outside inward with conventional single-direction pressing, the patent employs simultaneous pressing from multiple directions (inside outward and outside inward) through multiple dies. This inverted approach allows material to be compressed uniformly from all directions, preventing material flow that would create burrs on the surface, while maintaining high manufacturing efficiency.
3Adaptability or versatility
If cutting processing is used to manufacture drive shaft, then manufacturing flexibility is achieved, but material loss increases and manufacturing time increases
Solution Approach 1:
The patent fundamentally changes the manufacturing parameter from subtractive cutting processing to additive cold forging. By transforming the material through plastic deformation under controlled pressure rather than removing material through cutting, the process achieves manufacturing flexibility for complex shapes while eliminating material loss and reducing manufacturing time.
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
This method enables the efficient and accurate manufacturing of constant velocity drive shafts by preventing burr formation and reducing the number of processing steps, resulting in lower costs and improved quality.
Implementation Method 1
an annealing step of partially annealing a molding material at positions where a first large-diameter part and a second large-diameter part included in the constant velocity drive shaft are respectively molded
Implementation Method 2
a cooling step of cooling the molding material partially annealed in the first step
Implementation Method 3
a molding step of molding in one step a first large-diameter part, a second large-diameter part, and a third large-diameter part in the molding material cooled in the second step by pressing with the metal mold pair and pressing from both directions of the molding material
Data Source
Figure 1
Figure 2
Figure 3(a)~3(d)
AI summary
An object is to provide a constant velocity drive shaft manufacturing method capable of manufacturing particularly a constant velocity drive shaft among drive shafts with high efficiency and with stable and high accuracy. A method for manufacturing a constant velocity drive shaft by full enclosed die cold forging including a metal mold pair including an upper metal mold and a lower metal mold includes an annealing step of partially annealing a molding material at positions where a first large-diameter part and a second large-diameter part included in the constant velocity drive shaft are respectively molded, a cooling step of cooling the molding material partially annealed in the first step, and a molding step of molding in one step a first large-diameter part, a second large-diameter part, and a third large-diameter part in the molding material cooled in the second step by pressing with the metal mold pair and pressing from both directions of the molding material.