PEX Expansion Tool With Variable Mandrel Stroke for Tube Fit-Up
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing PEX tubing expansion tools lack versatility and efficiency in expanding PEX tubing to different diameters and adapting to varying temperature conditions, leading to inconsistent sealing times and potential fitting insertion challenges.
Innovation Solution
A PEX expansion tool with a motor-driven mandrel system, including a transmission mechanism that provides different gear ratios based on rotational direction, and interchangeable heads with temperature compensation, allowing for precise expansion and adaptation to different PEX tubing sizes and temperature ranges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single fixed mandrel stroke length is used, then the device structure is simple, but it cannot adapt to different PEX tubing sizes and temperature conditions
Solution Approach 1:
The mandrel stroke length is made variable through a adjustable positioning mechanism that allows the mandrel to be positioned at multiple discrete locations along its travel path. This enables the expansion tool to adapt to different PEX tubing sizes and temperature conditions by selecting appropriate stroke lengths, while maintaining a relatively simple overall device structure through mechanical adjustment rather than multiple complete tools.
Solution Approach 2:
The expansion tool is designed with a universal head that can perform multiple expansion functions across different PEX tubing sizes. The adjustable mandrel positioning system allows a single tool to serve multiple purposes by varying the stroke length, eliminating the need for multiple specialized tools for different tubing dimensions and temperature conditions.
2Manufacturing precision
If manual adjustment of mandrel position is used, then the device structure is simple, but the expansion precision is inconsistent
Solution Approach 1:
The mandrel positioning mechanism pre-establishes discrete, predetermined positions along the mandrel travel path that correspond to specific expansion diameters. This preliminary configuration of positions ensures that when the mandrel is adjusted to a particular position, the expansion precision is maintained without requiring complex real-time control systems during the actual expansion operation.
Solution Approach 2:
The system replaces manual estimation and rough adjustment with a mechanical positioning system that provides discrete, repeatable positions. This mechanical substitution ensures consistent expansion precision by eliminating human error in positioning while maintaining simplicity through purely mechanical means rather than electronic controls.
3Productivity
If the mandrel reciprocates continuously, then the productivity is high, but the sealing time consistency deteriorates due to temperature variations
Solution Approach 1:
The mandrel reciprocation system is made dynamically adjustable, allowing the operator to modify the reciprocation speed and stroke length based on temperature conditions and PEX tubing characteristics. This dynamic adjustment enables maintenance of high productivity through rapid reciprocation when appropriate, while also allowing slowing down or extending sealing time when temperature variations require more careful control, thus ensuring sealing time consistency.
4Manufacturing precision
If fixed gear ratio transmission is used, then the mechanical structure is simple, but the expansion diameter control precision is insufficient for different tubing sizes
Solution Approach 1:
The transmission mechanism incorporates variable gear ratios that can be adjusted based on the PEX tubing size and desired expansion diameter. This dynamic transmission system allows precise control of the mandrel reciprocation speed and force for different tubing dimensions, while maintaining mechanical simplicity through discrete gear selections rather than continuous variable transmission.
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 tool efficiently expands PEX tubing to various diameters and optimizes sealing performance across temperature ranges, reducing fitting insertion time and ensuring consistent connections.
Implementation Method 1
a transmission having an input member configured to receive a rotational input from the motor shaft and an output member rotatable in response to rotation of the input member, and a drive mechanism configured to convert rotation of the output member into translational movement of the mandrel. The transmission is configured to provide a first gear ratio from the input member to the output member in response to rotation of the motor shaft in a first direction, and the transmission is configured to provide a second gear ratio from the input member to the output member in response to rotation of the motor shaft in a second direction opposite the first direction
Implementation Method 2
The PEX tube elastically recovers around the fitting to form a tight connection
Data Source
AI summary
An expansion tool includes a housing, a motor supported by the housing and including a motor, a mandrel, and a drive mechanism configured to convert a rotational input from a motor shaft into translational movement of the mandrel. The expansion tool includes a first operating mode and a second operating mode. When the expansion tool is operated in the first operating mode, the drive mechanism is configured to reciprocate the mandrel between a retracted position and a first extended position. When the expansion tool is operated in the second operating mode, the drive mechanism is configured to reciprocate the mandrel between the retracted position and a second extended position different than the first extended position.