Thermoplastic Clutch Hydraulic Cylinder With Flexible Rod Coupling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hydraulic cylinders for motor vehicles face issues with surface defects due to thermal contraction of thermoplastic materials, leading to hydraulic tightness compromise and the need for additional finishing work on thermosetting inserts to mitigate these defects.
Innovation Solution
A hydraulic cylinder design featuring a thermoplastic insert with elastically flexible fins and a stop ring for axial coupling, allowing the rod to oscillate without significant strain on the insert, and using thermoplastic material for both the piston and insert, eliminating the need for thick thermosetting inserts and their associated finishing challenges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If thermoplastic material is used to form the piston with greater thickness, then the structural strength is improved, but surface defects occur due to thermal contraction during cooling and solidification
Solution Approach 1:
The piston is divided into two functional parts: a thin-walled thermoplastic tubular structure providing hydraulic tightness and a separate thermosetting insert providing structural strength. This segmentation allows each material to be optimized for its specific function without the trade-off present in monolithic designs.
Solution Approach 2:
The invention uses a composite structure combining thermoplastic material for the piston body and thermosetting material for the insert. This composite approach leverages the advantages of both materials: thermoplastic for ease of manufacturing and hydraulic sealing, and thermosetting for structural strength and dimensional stability.
2Strength
If thermosetting material insert is used to provide structural strength, then the strength is improved, but additional finishing work is required to remove burrs formed during molding
Solution Approach 1:
The retaining elements are pre-formed as integral parts of the thermosetting insert during the molding process itself, rather than requiring subsequent machining or finishing operations. This preliminary formation of functional features eliminates additional manufacturing steps.
Solution Approach 2:
The thermosetting insert automatically forms its own retaining elements and structural features during molding without requiring external intervention or post-processing. The material self-organizes into the required functional geometry through the molding process.
3Manufacturing precision
If thin tubular thermoplastic piston structure is used, then thermal contraction defects are reduced, but the structural strength is compromised
Solution Approach 1:
The piston is divided into two functional parts: a thin-walled thermoplastic tubular structure providing hydraulic tightness and a separate thermosetting insert providing structural strength. This segmentation allows each material to be optimized for its specific function without the trade-off present in monolithic designs.
Solution Approach 2:
The invention uses a composite structure combining thermoplastic material for the piston body and thermosetting material for the insert. This composite approach leverages the advantages of both materials: thermoplastic for ease of manufacturing and hydraulic sealing, and thermosetting for structural strength and dimensional stability.
4Stability of the object's composition
If thick thermosetting insert is used to accommodate rod coupling, then the coupling stability is improved, but thermal contraction problems are experienced
Solution Approach 1:
The invention changes the material parameter from thermosetting to thermoplastic for the piston and insert, fundamentally altering the thermal behavior. Thermoplastic materials exhibit different thermal contraction characteristics during cooling, reducing the formation of surface defects while maintaining adequate structural integrity for rod coupling.
Solution Approach 2:
The piston is divided into two functional parts: a thin-walled thermoplastic tubular structure providing hydraulic tightness and a separate thermosetting insert providing structural strength. This segmentation allows each material to be optimized for its specific function without the trade-off present in monolithic designs.
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 provides stable and reliable axial coupling between the piston, insert, and rod, reducing thermal contraction issues and simplifying the production process by avoiding the need for extensive finishing work on thermosetting materials.
Implementation Method 1
surface defects that occur as a result of the thermal contraction during the cooling and solidification phase of the thermoplastic element
Implementation Method 2
The insert comprises a partially spherical seat that is designed to receive and hold a spherical head of a rod
Implementation Method 3
A stop ring integrally mounted to the cylinder body comprises a partially spherical concave surface that faces the piston and may cooperate in a thrust relationship against a corresponding partially spherical convex surface formed by the rod
Data Source
AI summary
A hydraulic cylinder is provided which has a body forming a hydraulic chamber, in which a tubular piston made of thermoplastic material slides. An insert is locked in an internal cavity of the piston and has a spherical seat configured to receive and retain a spherical head of a rod connectable to a control pedal. The insert is made of thermoplastic material and forms a plurality of flexible fins adjacent to the spherical seat. The flexible fins have retaining elements protruding in a radially internal direction to hold the spherical head of the rod. A tensile force exerted by the rod away from the insert is transferred to a body of the piston by a stop ring.