Pipe assembly, compressor, refrigeration device, and method for manufacturing pipe assembly
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Solution Overview
Problem
The deviation of metal members at the joint portion during brazing in refrigerant flow path members can cause defects, reducing the strength and leading to operation failures in compressors and refrigeration apparatuses.
Innovation Solution
A tube assembly comprising an inner and outer tube with specific dimensions and expansion coefficients, along with a brazing material, is designed to maintain a stable brazing gap and secure the shape and strength by press-fitting and brazing, ensuring the inner and outer tubes are firmly fixed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a large gap is maintained at the joint portion of two metal members during brazing, then the brazing process can be performed, but the positions or orientations of the two metal members may deviate, causing defects and reducing strength
Solution Approach 1:
The inner tube is inserted into the outer tube, creating a nested structure where the inner tube's outer peripheral surface contacts the outer tube's inner peripheral surface. This nesting maintains a stable brazing gap while preventing positional deviation through surface contact, resolving the contradiction between brazing processability and positional accuracy.
Solution Approach 2:
The brazing material acts as an intermediary substance filled in the brazing gap between the inner and outer tubes. It facilitates the brazing process while the contact between the tubes' peripheral surfaces ensures positional stability, allowing both good brazing processability and manufacturing precision.
2Ease of manufacture
If the inner tube and outer tube are joined by brazing alone, then the joint can be formed, but the overall shape and strength of the tube assembly may be insufficient
Solution Approach 1:
The invention combines two joining methods: contact between the outer peripheral surface first portion and inner peripheral surface first portion, and brazing with brazing material in the brazing gap. This merged approach provides both easy joint formation and enhanced overall strength, resolving the contradiction between ease of manufacture and tube assembly strength.
3Volume of moving object
If the inner tube has a large inner diameter, then the injection path is adequate, but the brazing gap may be too large for proper brazing
Solution Approach 1:
The outer tube's inner peripheral surface is designed with different characteristics at different locations: the inner peripheral surface first portion contacts the inner tube to provide structural support, while the inner peripheral surface second portion forms an appropriate brazing gap with the outer peripheral surface second portion. This local differentiation allows large inner diameter for injection path capacity while maintaining proper brazing gap quality.
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 solution maintains the shape and enhances the strength of the tube assembly, thereby preventing malfunction in compressors and refrigeration apparatuses by stabilizing the positional relationship between the inner and outer tubes.
Implementation Method 1
The brazing material is disposed in a brazing gap between the outer peripheral surface second portion and the inner peripheral surface second portion. The brazing material fixes the outer peripheral surface second portion and the inner peripheral surface second portion.
Implementation Method 2
The inner tube has an inner tube linear expansion coefficient. The outer tube has an outer tube linear expansion coefficient larger than the inner tube linear expansion coefficient.
Data Source
Figure 1
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AI summary
A tube assembly (60) includes an inner tube (70), an outer tube (80), and a brazing material (61). The inner tube (70) includes an outer peripheral surface first portion (71) and an outer peripheral surface second portion (72). The inner tube (70) constitutes a refrigerant passage of a compressor (11). The outer tube (80) includes an inner peripheral surface first portion (81) and an inner peripheral surface second portion (82). The outer tube (80) constitutes an injection path (54). The inner tube (70) is partially inserted into the outer tube (80) such that the outer peripheral surface first portion (71) is in contact with the inner peripheral surface first portion (81). The brazing material (61) is disposed in a brazing gap (65) between the outer peripheral surface second portion (72) and the inner peripheral surface second portion (82). The brazing material (61) fixes the outer peripheral surface second portion (72) and the inner peripheral surface second portion (82).