Straddle-Type Vehicle Braking Apparatus with Segmented Hydraulic Mechanisms

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional straddle-type vehicle braking systems experience poor operation feeling due to high hydraulic pressure in the front wheel braking mechanism when the rear wheel braking mechanism is activated, making it difficult to strengthen the front wheel braking force.

Innovation Solution

The braking apparatus is designed with a first braking mechanism actuated only by the operating member and a second braking mechanism actuated only when no assist action is performed, allowing the assist action to increase liquid pressure in the second braking mechanism, thereby reducing pressure in the first mechanism and improving the operation feeling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If the assist mechanism supplies auxiliary braking force to the front wheel when the rear wheel braking mechanism is activated, then the braking force of the rear wheel is improved, but the liquid pressure in the front wheel hydraulic passage becomes high making the operating lever hard to actuate

Engineering Contradiction:
Improvebraking forceVSAvoidoperation feeling of operating lever
Core Design Contradiction:
ForceVSEase of operation

Solution Approach 1:

The front wheel braking mechanism is divided into two independent subsystems: a first braking mechanism (front master cylinder 21, first hydraulic passage 24, first caliper 23) that operates only when the operating member is actuated, and a second braking mechanism (second hydraulic passage 29, second caliper 28) that operates only when assist action is performed. This segmentation isolates the high-pressure assist operation from the manual operating lever, allowing the lever to remain soft while still enabling strong braking through the second mechanism during assist mode.

Inventive Principle:
Principle #1Segmentation

2Power

If the assist mechanism is activated to strengthen braking, then the braking effectiveness is improved, but the hardness of the operating member actuation increases due to high liquid pressure

Engineering Contradiction:
Improvebraking powerVSAvoidbraking mechanism complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The braking system is segmented into two independent mechanisms with separate hydraulic passages and calipers. The first braking mechanism handles manual operation only, while the second braking mechanism handles assist-only operation. This allows the system to achieve high braking power through the second mechanism during assist mode without increasing the complexity of the manual operation path.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different parts of the front wheel braking system are assigned different functions: the first braking mechanism (with master cylinder) provides soft manual operation, while the second braking mechanism (without master cylinder) provides high-power assist braking. This local differentiation of quality allows each subsystem to optimize for its specific purpose without compromising the other.

Inventive Principle:
Principle #3Local quality

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 reduces the hardness of the operating member's actuation and enhances the operation feeling by ensuring the assist action does not affect the first braking mechanism, resulting in a more responsive and sensitive braking experience.

Implementation Method 1

a first hydraulic passage (24) establishing communication and connection between the first caliper (23) and the front master cylinder (21)

Methodology Applied
Scientific EffectHydraulic pressure transmission: Hydraulic Press

Data Source

PatentEP2075169B1Braking apparatus and straddle-type vehicle provided therewith
Publication Date: 2014.09.10 YAMAHA MOTOR CO LTD
  • EP2075169B1 patent drawingFigure 1
  • EP2075169B1 patent drawingFigure 2
  • EP2075169B1 patent drawingFigure 3

AI summary

A braking apparatus provides improved operation feeling of an assisted braking action, and a straddle-type vehicle provided with the braking apparatus. A braking apparatus 16 is provided with a front wheel braking mechanism 17 braking a front wheel in response to operation of a front operating member 20, a rear wheel braking mechanism 18 braking a rear wheel in response to operation of a rear operating member 32, and assist mechanisms 19a, 19b assisting braking actions caused by the front wheel braking mechanism 17 and the rear wheel braking mechanism 18. At least one of the front wheel braking mechanism 17 and the rear wheel braking mechanism 18, for example, the front wheel braking mechanism 17 is provided with a first braking mechanism 17a and a second braking mechanism 17b. The first braking mechanism 17a is actuated only when the front operating member 20 is operated. The second braking mechanism 17b is actuated only when the front operating member 20 is operated in a case where no assist action is performed, and is actuated by the assist action in a case where the assist action is performed.