Disc Brake Caliper Boss Layout for Tool Clearance
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Solution Overview
Problem
Conventional vehicle disc brakes with multiple boss parts in parallel on the disc outer peripheral side suffer from poor workability due to tool interference when screwing in bleeder screws or banjo bolts, limiting the movable range.
Innovation Solution
The vehicle disc brake design positions at least two boss parts at both ends in the disc rotational direction closer to the disc rotor than the others, providing bearing surfaces for bleeder screws and banjo bolts, and includes a banjo with a hose connection part and rotation stopper to enhance screwing and hose connection without interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If three or more boss parts are provided in parallel on the disc outer peripheral side, then the hydraulic system becomes more reliable with multiple connection points, but tool interference occurs when screwing in bleeder screws or banjo bolts into intermediate boss parts
Solution Approach 1:
The patent applies local quality by providing different radial position arrangements for different boss parts. Specifically, boss parts at both ends in the disc rotational direction are positioned closer to the disc rotor, while intermediate boss parts are positioned farther away. This localized differentiation in positioning resolves the tool interference problem for intermediate boss parts while maintaining the reliability benefits of multiple parallel connection points.
2Ease of operation
If boss parts are positioned closer to the disc rotor, then tool movable range is extended and workability is improved, but the structural compactness of the caliper body is reduced
Solution Approach 1:
The patent segments the boss parts into different groups based on their radial positioning. Boss parts at both ends are positioned at one radial distance (closer to the disc rotor), while intermediate boss parts are positioned at a different radial distance (farther away). This segmentation allows each group to serve its specific function optimally without compromising overall structural compactness.
Data Source
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AI summary
The present invention provides a vehicular disc brake in which bleeder screws and/or banjo bolts can be satisfactorily threaded into a boss part provided with a union hole and/or a boss part provided with a bleeder hole, the boss parts being provided to a caliper body, wherein a first union boss part 5h, a second union boss part 5j, and a second bleeder boss part 5k, which are aligned on the outer side of a caliper body 5 with respect to a disc radial direction, are disposed such that the first union boss part 5h disposed on a disc turn-out side and the second union boss part 5j disposed on a disc turn-in side are nearer to a disc rotor than is the second bleeder boss part 5k disposed in the center. A bearing surface position S1 of a banjo bolt 20 attached to the first union boss part 5h and a bearing surface position S2 of a banjo bolt 20 attached to the second union boss part 5j protrude further outward in the disc radial direction than does a bearing surface position S3 of a bleeder screw 18 attached to the second bleeder boss part 5k.