Percussion Piston Insert Assembly With Shrinking Adhesion Joint
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing ground drilling devices face challenges in handling, maintenance, and repair due to complex and costly joining processes, particularly with friction welding and shrinkage connections, which require large oversized dimensions and high temperature differences, leading to potential damage and increased manufacturing costs.
Innovation Solution
A shrinking adhesion connection is used to hold an insert in the percussion piston's impact section, allowing for a reduced oversized dimension and lower temperature differences, enabling easier assembly and disassembly, with the insert remaining at room temperature and the housing section heated to form the connection, using anaerobic adhesives or epoxy resins for secure and reversible attachment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If friction welding is used to join the insert in the housing, then the mechanical strength of the connection is improved, but the manufacturing cost and complexity increase due to costly machining of the friction weld seam
Solution Approach 1:
The patent changes the joining parameters from friction welding to shrinking adhesion connection, using temperature differential to create a secure connection without requiring costly post-weld machining. The insert is heated to expand it, then inserted into the housing where it cools and contracts to form a tight fit.
Solution Approach 2:
The patent replaces the mechanical friction welding process with a thermal expansion and adhesion-based shrinking connection. This substitution eliminates the need for complex friction welding equipment and subsequent machining operations, reducing manufacturing cost while maintaining connection integrity.
2Ease of manufacture
If a shrinkage connection is used to hold the insert, then the need for further machining is eliminated, but the connection becomes hard to release for maintenance and repair
Solution Approach 1:
The patent uses temperature as a controllable parameter to enable both secure connection and easy release. By heating the insert, the adhesion connection is weakened or broken, allowing for simple removal. For normal operation, the insert is at room temperature and firmly adhered to the housing.
Solution Approach 2:
The patent creates a dynamic connection that can transition between strongly adhered and easily separable states based on temperature conditions. This dynamic property allows the same connection mechanism to serve both manufacturing and maintenance requirements.
3Strength
If a large oversized dimension is used for the shrinkage connection, then the mechanical strain resistance is improved, but the temperature difference required for joining increases, potentially damaging components
Solution Approach 1:
The patent optimizes the oversized dimension parameter to achieve an balance between strain resistance and temperature requirements. By carefully selecting the degree of oversizing, the connection achieves sufficient strength while requiring only moderate temperature differences that do not damage the housing or insert.
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 solution reduces manufacturing costs, allows for thinner-walled designs, lowers stress on components, and facilitates easier handling and maintenance by enabling the use of a shrinking adhesion connection that is more forgiving and adaptable, with the ability to reuse the insert and housing components without damage, while maintaining mechanical integrity.
Implementation Method 1
The insert is introduced into the heated, enlarged part, especially the housing
Implementation Method 2
using anaerobic adhesives or epoxy resins for secure and reversible attachment
Data Source
AI summary
A ground drilling device with a percussion piston for drilling into the soil, comprising at least one housing section for the percussion piston, wherein an insert is arranged in the housing between the drilling head tip and the percussion piston such that the insert transmits at least a portion of the energy of the percussion piston to the housing, and the insert is held in the housing by means of a shrinking adhesion connection.