Drum Brake Torque Sensing With Wear-Resistant Shaft Hole
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Solution Overview
Problem
Existing brake torque detection devices suffer from detection data distortion due to indentation grooves on the brake arm shaft hole, leading to inaccurate brake torque measurements, especially when the brake disc is immersed in oil or water or overheated, and the friction coefficient changes.
Innovation Solution
The drum brake design incorporates an oblong shaft hole with a wear-resistant strip and a sensing plate connected to a tension and compression sensor, converting the brake shoe shaft's displacement into electrical signals for real-time torque detection, while the wear-resistant strip prevents indentation grooves, maintaining accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a pressure sensor is added to detect brake spring working pressure, then brake torque can be calculated, but detection accuracy deteriorates when friction coefficient changes due to oil, water, or overheating
Solution Approach 1:
The patent replaces the pressure sensor-based mechanical detection system with a torque sensor that directly measures brake torque. This substitution eliminates the need to calculate torque through friction coefficient multiplication, thereby resolving the accuracy deterioration that occurs when friction conditions change due to oil, water, or overheating.
2Strength
If the brake arm uses high toughness material to prevent quenching, then toughness is improved, but manufacturing precision deteriorates due to indentation grooves on the shaft hole wall
Solution Approach 1:
The patent applies local quality by adding a wear-resistant strip specifically at the shaft hole location where precision is critical. This allows the brake arm to maintain high toughness in the overall structure while providing localized high hardness and wear resistance at the shaft hole wall, preventing indentation grooves without requiring quenching of the entire brake arm.
Solution Approach 2:
The patent uses composite materials by combining the base brake arm material (high toughness) with a wear-resistant strip material (high hardness) at the shaft hole location. This composite structure allows the brake arm to maintain its required toughness while the wear-resistant strip prevents indentation grooves, resolving the contradiction between toughness and manufacturing precision.
3Stability of the object's composition
If the brake shoe shaft is constrained in the shaft hole, then positioning is improved, but measurement precision deteriorates due to inhibition of tiny movement
Solution Approach 1:
The patent applies local quality by providing a wear-resistant strip at the specific location where the brake shoe shaft contacts the shaft hole wall. This localized treatment allows the shaft to maintain stable positioning while reducing friction and preventing indentation grooves that would inhibit the tiny movement needed for accurate displacement measurement.
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 ensures accurate real-time detection of brake torque by minimizing friction force deviations and eliminating indentation grooves, enhancing the precision of brake torque measurements.
Implementation Method 1
a tension and compression sensor arranged on the sensing plate; one end of the sensing plate is connected to the brake shoe shaft, and the other end of the sensing plate is connected to the brake arm
Implementation Method 2
a hole wall at one side of the oblong shaft hole is provided with a wear-resistant strip configured for pressing against the brake shoe shaft during braking of the drum brake
Data Source
AI summary
The present application relates to a drum brake, which includes a brake arm; a brake shoe; a base; and a brake torque detection device; the brake shoe is hinged on the brake arm through a brake shoe shaft, the brake arm is provided with a shaft hole penetrating through the brake shoe shaft, and the shaft hole is an oblong shaft hole, and a hole wall at one side of the oblong shaft hole is provided with a wear-resistant strip configured for pressing against the brake shoe shaft during braking of the drum brake; the brake torque detection device includes a sensing plate and a tension and compression sensor arranged on the sensing plate; one end of the sensing plate is connected to the brake shoe shaft, and the other end of the sensing plate is connected to the brake arm.