Railway Door Rack Locking Joint for Secure Closed-Door Retention
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Solution Overview
Problem
Existing door drive devices for railway vehicles lack a secure mechanism to prevent doors from opening during vehicle motion, necessitating a firm connection of the locking mechanism to the rack.
Innovation Solution
A door drive device with a connecting member that is firmly attached to a rack using a fastening member, ensuring the connecting member is secured in a direction intersecting the rack's extending direction, utilizing a wedge-shaped first and second wall configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the locking mechanism is connected to the rack without a fastening member, then the device complexity is reduced, but the reliability of the connection is insufficient to prevent door opening during vehicle motion
Solution Approach 1:
The connection structure is divided into separate components: the rack with its extending walls, the connecting member with opposing walls, and the fastening member. This segmentation allows each component to perform its specific function - the walls provide structural support and alignment, while the fastening member provides secure attachment, thereby achieving reliable connection without excessive complexity.
Solution Approach 2:
The fastening member acts as an intermediary element that bridges the rack and the connecting member. It transfers and distributes the locking forces between these components, ensuring a secure connection that can withstand the forces applied during vehicle motion while maintaining a relatively simple overall structure.
2Reliability
If the connecting member is loosely attached to the rack, then the ease of manufacture is improved, but the door may open unintentionally during vehicle motion or power outages
Solution Approach 1:
The rack is designed with extending walls that protrude in advance toward the connecting member. This preliminary positioning action facilitates easy alignment and attachment of the connecting member during assembly, while the subsequent addition of the fastening member ensures reliable door locking during vehicle operation or power outages.
3Strength
If the fastening member secures the connecting member in multiple directions, then the connection strength is improved, but the device complexity increases
Solution Approach 1:
The fastening member is strategically positioned to secure the connecting member at critical locations where forces are applied during door operation and vehicle motion. The opposing walls of the connecting member are designed to engage with the rack's extending walls at specific points, providing localized reinforcement that achieves sufficient attachment strength without requiring complex fastening throughout the entire structure.
Data Source
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AI summary
An aspect of the present invention provides a door drive device (1) for a railway vehicle. The door drive device (1) includes: a rack (31A, 31B) constituting a rack-and-pinion mechanism (30), the rack-and-pinion mechanism (30) being configured to transmit driving force of a drive unit (2) in order to open and close a door (11A, 11B), the drive unit (2) being configured to drive the door (11A, 11B), the door (11A, 11B) being configured to open and close a doorway (10) of a railway vehicle, the rack (31A, 31b) having a first wall (35, 135); a connecting member (50A, 50B) connecting (i) a locking mechanism (3) configured to lock the door (11A, 11B) so that the door (11A, 11B) is prevented from moving in an opening direction while the door (11A, 11B) is fully closed and (ii) the rack (31A, 31B), the connecting member (50A, 50B) having a second wall (55, 155) that butts up against the first wall (35, 135) in an extending direction of the rack (31A, 31B); and a fastening member (59) fastening the connecting member (50A, 50B) to the rack (31A, 31B) in a direction intersecting the extending direction.