Door Closer Hold-Open Force Calibration for Reliable Release
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Solution Overview
Problem
Existing door closers with hold-open devices often require manual adjustment of holding force, leading to incorrect settings that can cause unintentional door release or damage due to excessive force.
Innovation Solution
A method for automatically adjusting the holding force of a door closer using a control unit to determine and set a normal operating holding force based on a release force, with an actuator applying initial and reduced forces to detect and calculate the optimal holding force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If manual adjustment of holding force is used during installation, then the adjustment process is simple, but the holding force is often incorrectly set leading to malfunction
Solution Approach 1:
The door closer system performs self-adjustment of the holding force through an automated calibration process. The control unit automatically determines the release force by reducing the holding force until the door closes, then calculates the normal operating holding force by adding a predetermined overpressure force to the release force, eliminating the need for manual adjustment by installers
Solution Approach 2:
The system uses feedback from the door's actual closing behavior to automatically adjust the holding force. The control unit monitors when the door releases and closes, uses this information to determine the release force, and automatically sets the optimal holding force based on this feedback
2Reliability
If the holding force is set too high, then the door remains securely held open, but the door cannot be manually released and components may be damaged
Solution Approach 1:
The system dynamically adjusts the holding force parameter based on calculated requirements rather than using a fixed high value. By determining the release force and adding only the necessary overpressure force, the holding force is optimized to be high enough for secure retention but low enough to allow manual release without damage
3Ease of operation
If the holding force is set too low, then the door can be easily released manually, but even the closing force or a slight gust of wind can unintentionally release the door
Solution Approach 1:
The system optimizes the holding force parameter by calculating it as the release force plus a predetermined overpressure force. This ensures the holding force is sufficiently high to prevent unintentional release from closing force or wind, while still allowing intentional manual release when needed
4Measurement precision
If automatic adjustment of holding force is implemented, then precise adjustment is achieved, but the device complexity increases
Solution Approach 1:
The patent replaces manual mechanical adjustment with an automated electronic control system. The control unit electronically controls the actuator to automatically adjust the holding force based on the calibration process, eliminating the need for manual mechanical adjustment mechanisms
Solution Approach 2:
The system performs self-calibration automatically during installation or operation. The control unit autonomously executes the calibration process by controlling the actuator to reduce holding force until door closure occurs, then automatically calculates and sets the optimal holding force, reducing the need for complex external adjustment mechanisms
Data Source
Figure 1~3
AI summary
The invention relates to a method which is used to automatically adjust a holding force of a door closer for a door. The door closer is designed to close the door by applying a closing force and has an arrester device which can apply the holding force so as to arrest the door in a holding position against the closing force. The method comprises the following steps: - determining a release force at which the arrester device releases the closing movement of the door due to the closing force, and - adjusting the holding force to a normal holding force on the basis of the release force.