Disc Brake Pad Fixing Layout to Prevent Clunk Noise
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Solution Overview
Problem
In disc brake devices, the release of braking force can cause a clunk noise due to the collision between the radially outer side surface of the insertion hole and the radially outer side end portion of the pin, resulting from the moments acting on the pads during forward and reverse braking.
Innovation Solution
The posture of the inner and outer pads is regulated by selectively fixing the shim plate to specific pistons using a sheet-shaped adhesive, ensuring contact between the radially outer side surface of the insertion hole and the pin end portion, preventing the formation of gaps and collisions during braking and release.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pad is supported movably by the pad support member, then the pad can perform braking by pressing against the rotor, but the pad may collide with the pad support member causing clunk noise
Solution Approach 1:
The patent applies preliminary action by providing a moment regulating structure that pre-regulates the moment acting on the pad during braking. This prevents the pad from rotating excessively and colliding with the pad support member during brake release, thereby preventing clunk noise before it occurs. The moment regulating structure includes features like an abutting surface on the pad or pad support member that limits the rotation angle of the pad during braking operations.
Solution Approach 2:
The patent applies preliminary anti-action by designing a moment regulating structure that counteracts the moment causing pad rotation before collision can occur. The abutting surface arrangement creates a counter-moment that prevents excessive pad rotation during braking and brake release, thereby preventing the harmful collision and clunk noise.
2Adaptability or versatility
If the insertion hole and pin are not in constant contact, then the pad can rotate during braking to accommodate moments, but gaps form causing collision during release
Solution Approach 1:
The patent applies preliminary action by pre-establishing contact between the radially outer side surface of the insertion hole and the radially outer side end portion of the pin through moment regulation. This ensures constant contact during both braking and release operations, preventing gap formation and subsequent collision noise while still allowing necessary pad rotation during braking.
Solution Approach 2:
The patent applies parameter changes by modifying the moment acting on the pad through the moment regulating structure. By controlling the moment parameter, the pad's rotational behavior is adjusted to maintain contact between the insertion hole and pin throughout the braking and release cycle, preventing harmful collisions.
3Power
If the pad rotates during braking to support moment forces, then braking performance is maintained, but the pad posture becomes unstable during release
Solution Approach 1:
The patent applies preliminary action by pre-regulating the pad posture through the moment regulating structure before brake release occurs. The abutting surface arrangement ensures that the pad returns to a stable, predetermined position during release, preventing posture instability and associated collision noise while maintaining braking performance during active braking.
Solution Approach 2:
The patent applies parameter changes by controlling the moment parameter acting on the pad. During braking, the moment allows pad rotation for force transmission; during release, the moment regulation ensures the pad returns to a stable posture. This dynamic moment control balances power transmission needs with posture stability requirements.
Data Source
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AI summary
One aspect of the invention relates to a disc brake device (1a), which includes a pair of pads (3a, 4a), a pad support member (2a) supporting at least one of the pair of pads in a movable manner in an axial direction, and a plurality of pistons (27a, 27b, 27c, 28a, 28b) configured to press the one of the pads toward the rotor in the axial direction. Slide engagement portions (18a) engaged with the pad support member so as to be movable in the axial direction are respectively provided at both side portions of the one of the pads in a circumferential direction. The one of the pads is fixed to a tip end portion of at least one piston including a piston arranged at an end portion on a rotation-in side or a rotation-out side among the plurality of pistons, and is not fixed to a tip end portion of a remaining piston. Another aspect of the invention relates to a disc brake pad (3a, 4a).