Vehicle Door Module Fastening Clip With Cam-Driven Low-Torque Assembly

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing fastening devices for securing a door module to a door frame in vehicles are time-consuming, labor-intensive, and often require high torque due to manufacturing tolerances and burs from stamping processes, which can impede rotation and damage components.

Innovation Solution

A fastening clip device with a first component featuring a body and head, and a second component with cam surfaces and followers that transform rotational movement into longitudinal translation, allowing the retainer to bear against the door frame without contacting burs, thus reducing the necessary torque and facilitating secure assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a known securing device with cam surface and retainer is used to fasten door module to door frame, then the connection strength is improved, but the torque required for assembly increases significantly due to manufacturing tolerances and burs

Engineering Contradiction:
Improveconnection strengthVSAvoidtorque required
Core Design Contradiction:
StrengthVSForce

Solution Approach 1:

The retainer is positioned in advance to engage with the door frame surface before the cam surface compression phase. This preliminary positioning ensures that the retainer contacts the clean, bur-free surface of the door frame first, establishing a stable bearing point that prevents bur interference during subsequent cam surface engagement and reduces the torque needed for assembly

Inventive Principle:
Principle #10Preliminary action

2Reliability

If traditional fastening devices are used, then secure connection is achieved, but the assembly process becomes time-consuming and labor-intensive

Engineering Contradiction:
Improvesecure connectionVSAvoidassembly time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The fastening device performs multiple functions through a single rotational motion: the cam surface automatically compresses the seal, the retainer simultaneously engages and bears against the door frame, and the head secures the assembly. This self-service mechanism eliminates the need for separate operations, reducing assembly time while maintaining secure connection through the integrated multi-functional design

Inventive Principle:
Principle #25Self-service

3Ease of manufacture

If burs from stamping process are present on orifices, then manufacturing is simplified, but the rotation of fastening component is impeded or made impossible

Engineering Contradiction:
Improvestamping process simplicityVSAvoidrotation smoothness
Core Design Contradiction:
Ease of manufactureVSEase of operation

Solution Approach 1:

The retainer function is extracted and separated from the cam surface compression function. By providing a dedicated retainer element that engages the door frame surface independently, the system removes the dependency between cam surface engagement and surface quality. This allows the cam surface to compress the seal without being blocked by burs, maintaining rotation smoothness while preserving the simplicity of the stamping process

Inventive Principle:
Principle #2Taking out (Extraction)

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 device efficiently secures the door module to the door frame with reduced torque requirements, avoiding damage from burs and ensuring a robust, watertight seal, thereby simplifying the assembly process and enhancing the connection's reliability.

Implementation Method 1

At least one of the first and second components includes at least one cam surface and the other of the first and second components includes at least one follower configured to cooperate with the at least one cam surface, and to transform a rotational movement of the first component into a longitudinal translation movement

Methodology Applied
Scientific EffectCam mechanism: Cam

Data Source

PatentEP3538775B1Fastening clip device configured to secure a door module to a door frame of a vehicle
Publication Date: 2023.12.27 ILLINOIS TOOL WORKS INC
  • EP3538775B1 patent drawingFigure 1~4
  • EP3538775B1 patent drawingFigure 5~8
  • EP3538775B1 patent drawingFigure 9~12

AI summary

A device for securing a first unit to a second unit includes a first component (122) having a body (234) and a head (224). The body has an elongated shape and is configured to be inserted in at least one of a first orifice of the first unit and a second orifice of the second unit. The head is to an upper longitudinal end of the body and includes a part (226) that is configured to be rotationally engaged by a tool. The first component also includes a retainer (130) at a lower longitudinal end of the body. The retainer is configured to bear against a lower surface of the second unit. A second component is configured to couple to the first component. At least one of the first and second components includes at least one cam surface and the other of the first and second components includes at least one follower (144) configured to cooperate with the at least one cam surface, and to transform a rotational movement of the first component into a longitudinal translation movement of the first component in relation to the second component so that the retainer bears on the lower surface of the second unit.