Hydraulic Brake-Clutch Actuation with Direct Idle Stroke Adjustment

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Solution Overview

Problem

Existing hydraulic actuation devices for vehicle brakes and clutches face challenges in efficiently adjusting the idle stroke, often requiring complex designs that affect kinetic properties and are dependent on other adjustments, such as ratio adjustments.

Innovation Solution

The actuation device incorporates an idle stroke adjustment device with a nut-shaped adjusting body directly connected to the piston, allowing for direct and efficient adjustment of the piston's resting position, independent of other adjustments, and enabling quick replacement of lever assemblies without re-adjustment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the stroke free play adjustment device is actuated in a direction perpendicular to the direction of thrust, then the adjustment can be performed indirectly through the control lever assembly, but the kinetic properties of the device are affected and forces are generated in perpendicular directions

Engineering Contradiction:
Improveadjustment operationVSAvoidkinetic properties
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent inverts the conventional adjustment approach by actuating the adjustment device in the same direction as the thrust (longitudinal direction) rather than perpendicular to it. This reversal eliminates perpendicular force components and simplifies the kinetic analysis while maintaining ease of operation.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the actuation direction parameter from perpendicular to parallel with the thrust direction. This parameter change optimizes the force transmission path and improves the kinetic properties by eliminating unnecessary perpendicular force components that complicate the device behavior.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If the adjustment of the piston position is carried out indirectly through many components, then the stroke free play can be adjusted, but the design and manufacturing precision requirements increase due to the chain of tolerances

Engineering Contradiction:
Improveadjustment capabilityVSAvoiddesign and manufacturing precision
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent extracts the adjustment function from the complex indirect mechanism and implements it directly on the piston through a dedicated adjustment device. This extraction eliminates the chain of intermediate components (abutment surface, eccentric rod, portion hub, element for transmitting thrust, push rod seat) and their associated tolerance accumulation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a direct intermediary adjustment device that connects to the piston and enables direct position adjustment. This new intermediary replaces the complex indirect transmission path, reducing the number of components and minimizing the cumulative tolerance effects while maintaining adjustment capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If the stroke free play adjustment device is located between the control lever assembly and the pump assembly, then the adjustment can be integrated, but the performance depends on the control lever assembly and affects other parameter adjustments such as ratio adjustment

Engineering Contradiction:
ImproveintegrationVSAvoiddependence on control lever assembly
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the adjustment functions by providing a dedicated idle stroke adjustment device that is independent from the control lever assembly and ratio adjustment mechanisms. This segmentation allows each function to be adjusted independently without affecting the others, reducing interdependence and simplifying the overall system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent creates a universal adjustment capability by designing the idle stroke adjustment device to function independently of the control lever assembly. This allows the adjustment device to operate autonomously without being constrained by or affecting other adjustment parameters, providing greater versatility and independence.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4549267A1Actuation device for hydraulically actuating a brake or clutch of a vehicle
Publication Date: 2025.05.07 J JUAN SA
  • EP4549267A1 patent drawingFigure 1~2
  • EP4549267A1 patent drawingFigure 3
  • EP4549267A1 patent drawingFigure 4~5c

AI summary

An actuation device for hydraulically actuating a brake or a clutch of a vehicle, comprising a pump assembly (2) and an idle stroke adjustment device (3). A piston (23) is configured to slide inside a chamber (22) disposed within a pump body (21) along a pump actuating direction (X-X). The piston (23) is at least movable from a resting position (P1) to an operating position (P2), between which is defined a stroke free play (d1). The idle stroke adjustment device (3) comprises an idle stroke adjusting body (31) connected to the piston (23), movable along an idle stroke adjusting direction (X'-X') which is parallel to the pump actuating direction (X-X), wherein the movement of the idle stroke adjusting body (31) along the idle stroke adjusting direction (X'-X') causes the movement of the piston (23) along the pump actuating direction (X-X) to increase or decrease the stroke free play (d1).