Generator-Based Braking Device for Door Closers
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Solution Overview
Problem
Existing door closers with mechanical energy storage and braking devices face limitations in adjusting closing speed and implementing speed-dependent functions, are sensitive to temperature and friction changes, and pose environmental and safety risks due to damper oil leakage.
Innovation Solution
A braking device for movable door leaves that generates electrical energy from mechanical energy using a generator with evaluation and control electronics, allowing autonomous operation and precise control of closing speed through pulse width modulation, eliminating the need for external energy and combustible fluids.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If hydraulic valves and damper oil are used to control closing speed, then the door closer can operate autonomously without external energy, but the closing speed can only be adjusted within limited ranges and is sensitive to temperature and friction changes
Solution Approach 1:
The patent replaces the mechanical hydraulic valve system with an electrical braking system using a generator and electronic control. The generator converts mechanical energy from door movement into electrical energy, which is then used by electronic components (microcontroller, PWM circuitry) to control braking force. This substitution enables precise, programmable control of closing speed through software parameters rather than mechanical valve adjustments, dramatically expanding the adjustable range and eliminating sensitivity to temperature and friction variations.
Solution Approach 2:
The patent implements dynamic parameter changes by using pulse width modulation (PWM) to vary the braking force applied to the generator. The microcontroller adjusts the duty cycle of the PWM signal based on real-time feedback from speed sensors and pre-programmed parameters, allowing the closing speed to be precisely controlled throughout the entire door movement range. This enables independent adjustment of closing time, final impact speed, and intermediate speed profiles without being constrained by mechanical valve characteristics.
2Ease of operation
If hydraulic valves are used to regulate closing speed, then autonomous operation is achieved, but precise regulation of closing time and speed-dependent functions require complex trial-and-error adjustments
Solution Approach 1:
The patent implements a closed-loop feedback control system using speed sensors (such as Hall effect sensors or encoders) that continuously monitor the door leaf speed and feed this information back to the microcontroller. The microcontroller compares the measured speed with the desired speed profile stored in memory and dynamically adjusts the PWM duty cycle to maintain the target closing characteristics. This feedback mechanism eliminates the need for trial-and-error adjustments, as the system automatically adapts to achieve precise closing time and speed-dependent functions through programmable parameters.
Solution Approach 2:
The patent stores pre-calculated optimal control parameters in the microcontroller's memory before operation begins. These parameters include speed profiles, closing time targets, and braking force characteristics that have been determined through simulation or testing. During operation, the microcontroller simply retrieves and executes these pre-programmed parameters, eliminating the need for on-site trial-and-error adjustments. This preliminary action approach simplifies installation and commissioning while maintaining precise control capability.
3Ease of operation
If damper oil is used in the braking device, then autonomous operation is enabled, but environmental pollution and fire safety risks arise from oil leakage and flammability
Solution Approach 1:
The patent replaces the hydraulic damper oil system with an electrical generation and control system. Instead of using oil to provide damping forces, the system uses a generator to convert mechanical energy into electrical energy, which is then processed by solid-state electronic components (rectifiers, capacitors, microcontrollers, PWM circuits) to produce the braking effect. This substitution completely eliminates the use of flammable hydraulic fluids, removing fire safety risks and environmental pollution concerns while maintaining autonomous operation capability.
Solution Approach 2:
The patent employs solid-state electronic components and a generator that have no consumable fluids requiring disposal. Unlike damper oil that degrades over time, leaks, and requires environmental disposal, the electrical system uses durable solid-state components with no such limitations. The system generates its own operating energy from the door movement itself, storing it temporarily in capacitors, and produces no waste products, thereby eliminating the lifecycle environmental burden associated with hydraulic fluids.
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
Enables precise control of closing speed and time, independent of temperature and friction, with enhanced safety and environmental sustainability by using electrical energy storage and eliminating flammable oils, while allowing for parameterizable functions and maintenance data storage.
Implementation Method 1
a generator (22), the at least one generator shaft (24) of which can be rotated by a movement of the door leaf (5) and at whose connection terminals (K1, K2) a movement-dependent first output voltage (UA1) arises
Implementation Method 2
a braking circuit (14), which generates an effective braking force for damping the movement of the door leaf (5)
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
The invention relates to a braking device (20) for a moving door leaf (5) comprising a generator (22), the at least one generator shaft (24) of which can be rotated via a movement of the door leaf (5), and at the connection terminals of which a movement-dependent first output voltage occurs, which is applied to an evaluation and control electronics system (10) having an evaluation and control unit and a braking circuit, which generates an effective braking force for damping the movement of the door leaf (5), wherein the braking circuit (18) has at least one switch element, via which the connection terminals can be short-circuited, as well as a door closer (1) having a braking device of this type. According to the invention, a second output voltage of the generator (22) is applied to a charging circuit (12), which stores electrical energy for supplying the evaluation and control electronics system (10) with power.