Expansion Valve
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Solution Overview
Problem
The reduction in size of air conditioning devices has made it challenging to maintain installation space for expansion valves, and the use of expensive materials, while larger bubble diameters in refrigerant cause noise issues due to bubble entrainment and breakage within the valve chamber.
Innovation Solution
The use of a coil spring with a narrow space between its wires to reduce bubble size and minimize noise, eliminating the need for additional components and allowing for a more compact design by mounting the plug higher, thus reducing the valve body's vertical size and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of stationary object
If the expansion valve is reduced in size to save installation space and reduce material cost, then the valve body becomes more compact and cost-effective, but the refrigerant flow path becomes more constrained causing larger bubbles to accumulate and break, increasing noise
Solution Approach 1:
A bubble reduction mechanism is introduced as an intermediary component between the refrigerant inlet and the valve hole. This mechanism actively reduces large bubbles in the refrigerant to smaller sizes before they reach the valve hole, preventing the noise caused by large bubble breakage while maintaining the compact valve body design
Solution Approach 2:
The bubble size parameter in the refrigerant is actively changed from large to small through the bubble reduction mechanism. By controlling the bubble size parameter before refrigerant enters the valve hole, the system prevents noise generation while maintaining compact dimensions
2Object-generated harmful factors
If additional components are added to reduce bubble size and minimize noise, then noise is reduced, but the device complexity increases and installation space requirement increases
Solution Approach 1:
The bubble reduction mechanism is merged with the existing valve body structure, integrating multiple functions into a unified component. This eliminates the need for separate bubble reduction devices, reducing overall device complexity while maintaining noise reduction effectiveness
Solution Approach 2:
The valve body structure is designed to serve multiple functions: it acts as both the structural housing and incorporates the bubble reduction mechanism. This multi-functionality reduces the total number of components needed while achieving both noise reduction and structural support
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 configuration effectively reduces refrigerant passing noise and minimizes the use of metal materials, achieving a smaller, lighter, and less costly expansion valve while maintaining efficient refrigerant flow.
Implementation Method 1
a size of a space between the coil wires of the coil spring in an expanding and contracting direction of the coil spring is 0.54 mm or smaller in a valve closing state where the valve member abuts against the valve seat
Implementation Method 2
A valve member 32b is placed to face the valve seat. The valve member 32b is biased toward the valve seat by a compression coil spring 32c
Implementation Method 3
heat of the gas phase refrigerant flowing through the second passage 34 is transferred via the valve member driving rod 36f located in the second passage 34 and the pressure equalizing hole 36e and the diaphragm 36a
Implementation Method 4
The diaphragm driving fluid in the upper pressure operating chamber 36b is gasified by the transferred heat, and a pressure of the gas is applied to an upper surface of the diaphragm 36a
Data Source
Figure 1A~1B
Figure 2
Figure 3
AI summary
In an expansion valve, in a first passage 12 through which a high pressure liquid refrigerant flows, an inlet port 321 includes a large diameter passage portion 13 formed from one side surface to the other side surface of a valve body 30, and a small diameter passage portion 14 that provides communication between the large diameter passage portion 13 on the bottom end thereof and a valve chamber 15. A coil spring 20 provided in the valve chamber 15 biases a valve member 32b toward a valve hole 32a. An O ring 19 that seals between a plug 17 that supports a lower end of the coil spring 20 and the valve body 30 is located below the small diameter passage portion 14 and placed on the opposite side of the bottom end of the large diameter passage 13. Thus, the plug 17 that closes an opening of the valve chamber 15 can be mounted to an upper position, thereby reducing a vertical size of the valve body 30 to further reduce a size of the valve body, and reducing an amount of use of metal materials for the valve body to reduce weight and cost.