Single-Spool Four-Position Valve With Spring-Return Intermediate Stops
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Solution Overview
Problem
The complexity and increased component count of existing four-position switching valves due to two spools and two return springs make the manufacturing process difficult.
Innovation Solution
A simplified four-position switching valve design featuring a single spool with a spool moving mechanism that uses first and second driving parts and a spring member to achieve four switching positions, reducing the need for multiple springs and pistons.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If two spools and two return springs are provided in the valve hole, then the four-position switching valve can achieve four switching positions, but the component count increases and the structure becomes complex
Solution Approach 1:
The patent combines two separate spools and two return springs into a single integrated spool assembly with one return spring. The spool includes a spool body with a stepped structure that integrates the functions of both spools, and a single return spring acts on the spool body to provide restoring force for all four switching positions, thereby reducing component count while maintaining full switching capability.
Solution Approach 2:
The single spool body is designed with multiple functional surfaces and stepped sections that serve multiple purposes: it controls all four switching positions, provides sealing surfaces for all port configurations, and interacts with both pilot valves. The single return spring also serves a universal function by providing restoring force for all spool movements regardless of direction or position.
2Adaptability or versatility
If two spools and two return springs are provided in the valve hole, then the four-position switching valve can achieve four switching positions, but the manufacturing process becomes difficult
Solution Approach 1:
The patent combines two separate spools and two return springs into a single integrated spool assembly with one return spring. The spool includes a spool body with a stepped structure that integrates the functions of both spools, and a single return spring acts on the spool body to provide restoring force for all four switching positions, thereby reducing component count while maintaining full switching capability.
3Ease of manufacture
If a single spool with spool moving mechanism is used, then the structure and manufacturing process are simplified, but the valve must maintain four-position switching functionality
Solution Approach 1:
The spool body is segmented into multiple functional zones with different diameters and lengths, creating distinct sealing surfaces and pressure chambers. The stepped structure divides the spool into sections that independently control different port configurations, enabling four distinct switching positions while maintaining a single continuous spool component.
Solution Approach 2:
The patent utilizes the axial dimension of the spool by creating a stepped structure with varying diameters along the spool's length. This dimensional variation allows different sections of the spool to control different port configurations, effectively achieving four-position switching capability through axial geometry rather than requiring multiple separate spool components.
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 design simplifies the structure and manufacturing process while maintaining the functionality of the valve, allowing for easy production of an efficient four-position switching valve.
Implementation Method 1
a spring member that accumulates an elastic force for pushing-back the spool in the direction of the one-end-side switching position as the first driving part moves the spool to the other-end-side switching position and accumulates an elastic force for pushing-back the spool in the direction of the other-end-side switching position as the second driving part moves the spool to the one-end-side switching position
Implementation Method 2
When a pilot air pressure is applied to one piston through one pilot valve with the spring forces of the return springs being applied to the inner spool, the outer spool and the inner spool move in one direction
Data Source
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AI summary
[Object] To provide a simple-structured, easy-to-manufacture four-position switching valve. [Solution] A four-position switching valve 1 includes: a valve body 10 having a valve hole 18 communicating with a plurality of ports; a spool 30 that slides in the valve hole; first and second pistons 21 and 22 for driving the spool; and a spool moving mechanism part 42 that moves the spool to first and second intermediate switching positions between one-end side and the other-end-side switching positions. The spool moving mechanism part includes a compression spring 49 that accumulates an elastic force for pushing back the spool in the opposite direction as the spool moves toward the one-end-side switching position and accumulates an elastic force for pushing back the spool in the opposite direction as the spool moves toward the other-end-side switching position, and moves the spool to a first intermediate switching position with the elastic force of the compression spring when the pressure applied by the second piston is removed in a state in which the spool has been moved to the one-end-side switching position, and moves the spool to the second intermediate switching position with the elastic force of the compression spring when the pressure applied by the first piston is removed in a state in which the spool has been moved to the other-end-side switching position.