Trailer Coupling Arm Fixing Device Flat Bearing Surfaces
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Solution Overview
Problem
The existing trailer hitch systems face challenges in achieving a precise and low-backlash hold of the coupling arm with respect to the vehicle-side holder, often requiring precise manufacturing to avoid static overdetermination and noise issues due to form-fitting contours.
Innovation Solution
The design introduces a fixing concept where the support surface of the coupling arm bearing element and the abutment surface of the abutment body lie flat against each other without contact with the fixing body, allowing the coupling arm to be optimally supported on the holder while avoiding static overdetermination, with no positive-locking contours, and using bearing surfaces that slide along each other for precise positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the coupling arm bearing element protrudes as far as the fixing body to achieve engagement with the abutment body and fixing body in the fixing position, then a stationary fixing is achieved, but static overdetermination occurs requiring precise manufacturing to avoid noise and ensure low-backlash hold
Solution Approach 1:
The invention extracts the positive-locking contours from the support surface and abutment surface, removing the source of static overdetermination. The coupling arm bearing element is shortened so it does not reach the fixing body, eliminating the need for form-fitting contours on these surfaces while maintaining reliable fixing through the abutment body clamping mechanism.
Solution Approach 2:
The invention segments the fixing function from the support function. The support surface and abutment surface handle only support without form-fitting contours, while the fixing body and abutment body handle fixing through clamping. This separation eliminates the conflict between support and positive locking, reducing manufacturing precision requirements.
2Measurement precision
If form-fitting contours are provided on the support surface and abutment surface to prevent rotational play, then positioning precision is improved, but noise is generated during rotational movement about the pivot axis
Solution Approach 1:
The invention removes form-fitting contours from the support surface and abutment surface, eliminating the source of noise during rotation. Positioning precision is maintained through the precise location of the pivot axis and the clamping action of the abutment body, without requiring sliding form-fitting contours that generate noise.
3Ease of operation
If the coupling arm bearing element is supported flat on the abutment body without contact with the fixing body, then static overdetermination is avoided and rotational movement is smooth, but the fixing reliability must be ensured through alternative means
Solution Approach 1:
The invention makes the fixing system dynamic rather than static. The fixing body can move between a release position (allowing free rotation) and a fixing position (clamping the abutment body). This dynamic adjustment allows smooth rotational movement when needed while providing reliable fixing when required, without static overdetermination.
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
This solution ensures a precise and noise-free operation by maintaining the position of the coupling arm relative to the holder through sliding bearing surfaces, preventing unwanted rotational play and noise, while allowing for optimal support and anti-twist protection.
Implementation Method 1
the abutment surface and the support surface form bearing surfaces of the pivot bearing which slide along one another when the coupling arm is pivoted between the position of use and the position of non-use
Implementation Method 2
the abutment body is clamped between the fixing body and the coupling arm bearing element
Data Source
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AI summary
The invention relates to a trailer coupling (10) for a motor vehicle (200) with a coupling arm (20), wherein the coupling arm (20) is pivotably mounted on a holder (11) attached or attachable to the motor vehicle (200) by means of a pivot bearing (16) between a working position (G) and a non-working position (N), wherein in the working position (G) for attaching a trailer or attaching a load carrier the coupling arm projects further rearward in front of a rear (202) of the motor vehicle (200) than in the non-working position (N) provided for a non-working position of the coupling arm (20), wherein the pivot bearing (16) has a holder bearing receptacle (104) arranged on the holder (11) and a coupling arm bearing element (40) supporting the coupling arm, which is pivotably mounted on the holder bearing receptacle (104) about a pivot axis (S),wherein the trailer coupling (10) has a fixing device (160) for fixing the coupling arm to the holder (11) in the operating position (G) and/or the non-operating position (N), wherein in a fixing position (F) of the fixing device (160) a support body (80) fixedly arranged on the holder (11) is clamped between a fixing body (60) of the fixing device (160) and the coupling arm bearing element (40) (20) and is released in a release position (L), wherein in the fixing position (F) a fixing support surface (167) of the fixing body (60) rests against a fixing abutment surface (86) (83) of the abutment body (80) and a support surface of the coupling arm bearing element (40) rests against an abutment surface (86) of the abutment body (80), so that the coupling arm bearing element (40) With regard to the holder (11), it is pivotally movable in the release position (L) and fixed in the locking position (F). It is intended thatthat in the fixed position (F) the support surface (47) of the coupling arm bearing element (40) and the abutment surface (86) of the abutment body (80) are supported against each other over a flat surface and there is no contact between the coupling arm bearing element (40) and the fixing body (60).