Bicycle Brake Block Plastic Base Rubber Pad Composite Structure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional bicycle brake blocks made entirely of rubber by press molding have significant size tolerance issues, leading to assembly difficulties, deformation during use, reduced frictional effect, and premature wear, which can damage the holder when worn.
Innovation Solution
A brake block design featuring a plastic base with a rubber pad body, where the base is injection molded with a fixing portion and a connecting portion, the latter having necks and a connecting plate with a high coefficient of friction, ensuring a secure fit, reduced deformation, and visible wear indication through contrasting colors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the brake block is made entirely of rubber by press molding, then the manufacturing process is simple, but the size tolerance is large (+/-0.3mm) causing assembly difficulties and easy detachment from the holder
Solution Approach 1:
The brake block is divided into two distinct parts: a plastic base component and a rubber pad body. The base is manufactured by injection molding with high precision, while the pad body is separately molded and attached. This segmentation allows each component to be optimized for its specific manufacturing process, achieving both precision and ease of manufacture.
Solution Approach 2:
The brake block combines two different materials - plastic for the base and rubber for the pad body - each selected for its specific properties. The plastic base provides dimensional stability and precise fit, while the rubber pad provides friction and wear characteristics. This composite structure resolves the contradiction by leveraging the strengths of each material.
2Stability of the object's composition
If the brake block is made entirely of rubber, then the material is soft and conformable, but it deforms easily during operation reducing frictional effect
Solution Approach 1:
The functional requirements are segmented between two materials: the rubber pad body provides conformability and friction, while the plastic base provides structural rigidity and dimensional stability. This prevents the deformation issues that would occur if the entire block were made of soft rubber.
Solution Approach 2:
By combining rubber and plastic in a composite structure, the brake block achieves both the conformability needed for effective braking and the rigidity needed to maintain shape during operation. The rubber pad deforms slightly to conform to the wheel rim while the plastic base maintains overall structural integrity.
3Ease of manufacture
If the brake block is made entirely of rubber, then the material is easy to mold, but it is easily damaged when the holder directly contacts the wheel rim after wear
Solution Approach 1:
The plastic base acts as an intermediary protective layer between the holder and the wheel rim. When the rubber pad body wears down, the plastic base prevents direct contact between the metal holder and the wheel rim, thereby protecting the holder from damage. This intermediary function resolves the contradiction by adding a protective barrier.
4Manufacturing precision
If the brake block uses a plastic base with rubber pad body, then the assembly fit is improved, but the device structure becomes more complex
Solution Approach 1:
The rubber pad body is attached to the plastic base to form an integrated brake block assembly. The connecting portion of the base is designed to receive and secure the pad body, creating a unified component that functions as a single unit. This merging reduces the practical complexity despite the multi-material construction.
Solution Approach 2:
The plastic base is pre-manufactured with integrated features including the connecting portion and the groove for holder engagement. These features are built into the base during injection molding, eliminating the need for separate assembly steps for these critical fit features, thereby reducing overall assembly complexity.
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 provides a stable, durable brake block with improved assembly fit, enhanced frictional performance, extended lifespan, and alerts users to wear through audible cues, protecting the holder from direct contact with the wheel rim.
Implementation Method 1
the braking portion (20) formed on another side of the pad body (2) for providing frictional effect
Implementation Method 2
the base (1) manufactured by a plastic injection molding method
Implementation Method 3
the connecting plate (112) has a high coefficient of friction, such that a friction sound bursts when the connecting plate (112) is frictionally contacted for alerting wear of the pad body (2)
Data Source
AI summary
A brake block for bicycle includes a base which is made by plastic injection molding and a pad body made of rubber. The base has a fixing portion formed on one side thereof and a connecting portion formed on another side thereof. The connecting portion is connected with the fixing portion. The connecting portion has a plurality of necks connecting with the fixing portion and a connecting plate which is mounted on the necks. A gap is defined in two adjacent necks. The pad body has a braking portion formed on another side thereof for providing frictional effect. The pad body is partially filled into the gaps of the connecting portion of the base. The necks and the connecting plate are thoroughly covered by the pad body so that the base and the pad body form as an integral part.