Parking Brake Unit With Nested Pistons And Engaging Member
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional caliper brake devices are not suitable for use as parking brakes as they require compressed air to be maintained in the pressure chamber to function, making them unsuitable for applications where air supply can be unreliable.
Innovation Solution
A parking brake unit that includes a first piston, a biasing member, a second piston, and an engaging member, where the first piston moves within a pressure chamber due to hydraulic fluid pressure, and the second piston engages with the first piston to press the brake lining against the wheel disk, enabling braking without continuous compressed air supply.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If compressed air is maintained in the pressure chamber to enable the caliper brake device to function, then the braking function is achieved, but the system becomes unsuitable for parking brake applications where air supply may be unreliable
Solution Approach 1:
The brake system is divided into two independent piston systems: a first piston (110) for service braking using compressed air, and a second piston (120) for parking braking using a biasing member. This segmentation allows each subsystem to operate independently with its own power source, enabling the parking brake function to work reliably without depending on compressed air supply.
Solution Approach 2:
The engaging member (130) acts as an intermediary that couples the first piston and second piston. When the first piston moves, it drives the engaging member which in turn drives the second piston, allowing the service brake system to activate the parking brake system without direct mechanical connection to the brake lining.
2Device complexity
If a single piston system is used for both service and parking braking, then the device complexity is reduced, but the ability to function without continuous compressed air supply is lost
Solution Approach 1:
The second piston (120) is nested inside the first piston (110), with the first piston having a larger diameter than the second piston. This nested configuration allows two independent braking systems to occupy the same space, reducing overall device complexity while maintaining the reliability benefits of having separate power sources for service and parking braking.
Solution Approach 2:
The patent merges the service brake system and parking brake system into a single integrated unit with shared components such as the cylinder housing, seal structures, and brake lining actuation mechanism. This combining approach reduces the number of separate components needed while preserving the functional independence required for reliable parking brake operation.
3Duration of action of stationary object
If compressed air is continuously supplied to maintain brake engagement, then the brake remains active, but the system cannot be used for parking where air supply is unreliable
Solution Approach 1:
The biasing member (128) is pre-loaded to automatically engage the second piston and apply braking force when compressed air is not supplied. This preliminary action ensures that the parking brake is activated by default, eliminating the need for continuous air supply to maintain engagement, and making the system suitable for parking applications.
Solution Approach 2:
Instead of using compressed air to maintain brake engagement (positive brake), the system uses a biasing member to automatically engage the brake and requires air pressure to release it. This inverted approach ensures the brake remains engaged during parking without needing continuous air supply, transforming the system from a positive brake to a negative brake configuration.
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
The parking brake unit effectively engages and disengages the brake lining with the wheel disk, allowing for reliable braking during parking even when compressed air is not available, ensuring the brake can be switched between braking and non-braking states.
Implementation Method 1
a first piston (110, 210) formed in a cylindrical shape, the first piston having a first engaging part (first engaging groove (113)) on an inner circumference, the first piston being configured to move in first direction by pressure of hydraulic fluid supplied to a pressure chamber (105) defined in the back
Implementation Method 2
a first biasing member configured to bias the first piston in second direction, opposite to the first direction
Implementation Method 3
the second piston causes the brake lining to move in direction bringing the wheel to be in a braking state, when the first piston moves in the second direction
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
A parking brake unit (101) of a brake device (100) for braking a wheel (1) by supply of hydraulic fluid includes a first piston (110) formed in a cylindrical shape, the first piston (110) having a first engaging part (113) on an inner circumference thereof, the first piston (110) being configured to move in first direction by pressure of the hydraulic fluid supplied to a pressure chamber (105) defined in the back thereof, a first biasing member (118) configured to bias the first piston (110) in second direction, opposite to the first direction, a second piston (120) slidably provided on the inner circumference of the first piston (110), the second piston (120) having a second engaging part (123) on an outer circumference thereof, and an engaging member (130) configured to cause the first engaging part (113) and the second engaging part (123) to engage with each other, in which the second piston (120) causes a brake lining (2) to move in direction bringing the wheel (1) to be in a braking state, when the first piston (110) moves in the second direction.