Door Actuator Cam Piston Segmentation Reduces Opening Moment
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Solution Overview
Problem
Existing door closers require a large opening moment to preload the energy store, which can be a hindrance for children, older people, and individuals with physical disabilities, preventing barrier-free access.
Innovation Solution
A door operator design featuring a cam disk, an opening piston guided in a housing, a damping piston in a cylindrical cavity, and a compression spring for energy storage, with the damping piston and opening piston supported to prevent tilting, enhancing efficiency and reducing the required opening moment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional door closer with a cam disk and two pistons is used, then the closing moment can be achieved, but the opening moment becomes excessively large, hindering barrier-free access
Solution Approach 1:
The piston assembly is segmented into two separate pistons (first piston and second piston) that operate independently on opposite sides of the cam disk. This segmentation allows each piston to be optimized for its specific function: the first piston for opening with reduced force requirements, and the second piston for closing with high force generation, thereby resolving the contradiction between ease of opening and closing moment generation
Solution Approach 2:
Each piston is given different local qualities and characteristics. The first piston has a smaller surface area and is designed for low-force opening operation, while the second piston has a larger surface area and is designed for high-force closing operation. This local differentiation allows the system to achieve both easy opening and strong closing without requiring excessive force in either direction
2Productivity
If the opening piston is allowed to tilt slightly in its guide, then the structure remains simple, but the efficiency of the door operator decreases and more effort is required
Solution Approach 1:
A cylinder element is introduced as an intermediary component between the first piston and the housing. This cylinder element serves as a mediator that provides precise linear guidance to the first piston, preventing tilting and ensuring efficient force transmission to the cam disk, thereby improving operational efficiency without significantly increasing overall device complexity
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 design minimizes the opening moment required while maintaining a high closing moment, improving accessibility and efficiency by stabilizing the opening piston and reducing tilting issues, thus facilitating easier door operation for all users.
Implementation Method 1
an energy store (10) which acts on the opening piston (7) to store closing energy for the door; The energy store comprises at least one closing spring (10)
Implementation Method 2
a damping piston (16) which is guided in a cylindrical cavity (15) of a cylinder element (8)
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The invention relates to a door actuator (1) for actuating a door, comprising a housing (2), an output shaft (3) with a cam disc (6), an opening piston (7) which is guided in the housing (2) and bears against the cam disc (6) on a first side, an energy accumulator (10) which acts on the opening piston (7) and accumulates closing energy for the door, and a damping piston (16) which is guided in a cylindrical cavity (15) in a cylinder element (8) and bears against the cam disc (6) on a second side, wherein the cylinder element (8) is fixedly connected to the opening piston (7).