Wet Multi-Plate Brake Piston Stroke Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional vehicle wet-type multi-plate brake devices face issues with maintaining precise piston stroke control due to piston distortion and uneven motion, leading to brake dragging, loss torque, and deteriorated driving feel, especially when brake disks wear out.
Innovation Solution
The implementation of multiple hydraulic pistons arranged circumferentially around the brake center, each with an oil chamber and a piston sleeve, utilizing sliding resistance and a return plate with a return spring to maintain a consistent piston stroke, ensuring precise control and preventing brake dragging and loss torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single annular piston is used to operate the brake, then the structure is simple, but the contact surface of the piston against the disks is easily distorted and the motion cannot be uniform or high-precise
Solution Approach 1:
The single annular piston is divided into multiple separate pistons (typically three) arranged radially around the brake center. Each piston has its own cylinder and operates independently, eliminating the distortion issues of a large annular piston while maintaining structural simplicity. The segmented configuration allows for more precise and uniform stroke control.
Solution Approach 2:
The piston arrangement transitions from a single-plane annular configuration to a multi-dimensional radial arrangement around the brake center. This spatial redistribution allows each piston to contact the brake disks at different angular positions, ensuring uniform force distribution and preventing the distortion problems that occur with a single large contact surface.
2Device complexity
If the piston stroke is not constantly maintained, then the device structure remains simple, but the braking time and non-braking time change causing deteriorated driving feeling
Solution Approach 1:
A feedback mechanism is introduced where the stroke of each piston is monitored and automatically adjusted. The system detects deviations from the predetermined stroke and activates the adjusting means to restore the correct stroke, ensuring consistent braking performance and driving feel without requiring complex manual intervention.
Solution Approach 2:
The piston stroke control system is designed to automatically maintain the predetermined stroke through self-adjusting mechanisms. The system uses its own operational parameters to detect and correct stroke variations, eliminating the need for external adjustment mechanisms and maintaining simplicity while ensuring consistent performance.
3Force
If the number of brake plates is increased, then the braking capacity is improved, but drag occurs due to limitation in stroke regulation using the piston seal
Solution Approach 1:
The traditional piston seal-based stroke regulation mechanism is replaced with a hydraulic or electronic control system. This substitution allows for more precise and flexible stroke control that can accommodate increased numbers of brake plates without the mechanical limitations and drag issues inherent in seal-based systems.
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 provides a stable and high-precision automatic control mechanism that maintains piston stroke, reduces brake dragging and loss torque, and improves fuel efficiency and driving feel by uniformly applying brake force and accurately setting initial positions.
Implementation Method 1
a piston sleeve (61) is slidably provided between an inner-peripheral surface of a hydraulic piston hole (57) accommodating a hydraulic piston (55) and an outer-peripheral surface of the hydraulic piston (55), and a first piston seal (63) is provided on an outer-peripheral side of the piston sleeve (61)
Implementation Method 2
a second piston seal (65) is provided on an inner-peripheral side of the piston sleeve (61), and a sliding resistance of the second piston seal (65) is larger than that of the first piston seal (63)
Implementation Method 3
a sliding resistance of the second piston seal (65) is larger than that of the first piston seal (63)
Data Source
Figure 1
Figure 2
Figure 3
AI summary
In a vehicle wet-type multi-plate brake device, an automatic control mechanism is provided which has a simple structure and constantly maintains a piston stroke of a hydraulic piston, the mechanism being reliably operated. A piston sleeve 61 is slidably provided between an inner-peripheral surface of a hydraulic piston hole 57 accommodating a hydraulic piston 55 and an outer-peripheral surface of the hydraulic piston 55, and has a sliding resistance so as to move together with the hydraulic piston 55. Additionally, a return plate 67 is disposed so as to be capable of coming into contact with only the piston sleeve 61 and of moving by a predetermined distance together with the piston sleeve 61. When a hydraulic pressure is supplied to an oil chamber 59, the hydraulic piston 55 and the piston sleeve 61 move together by a predetermined distance C against a returning force of the return plate 67, and then only the hydraulic piston 55 slides until coming into contact with a brake plate so that a positional relationship between the hydraulic piston 55 and the piston sleeve 61 is constantly maintained and a stroke of the hydraulic piston 55 is constantly maintained.