Vehicle Control Lever Cam Mechanism for Neutral Play Reduction
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Solution Overview
Problem
Actuators used in motor vehicles, such as electronic gear selector switches, experience significant play in the neutral position, which can lead to the handle hitting the housing during motion and increased vibrations, compromising user ergonomics and control.
Innovation Solution
A cam mechanism is integrated into the connecting link to reduce play in the handle's neutral position by bracing it against the link wall, combined with a universal joint design for ergonomic pivoting movement and a compact configuration that includes a guide channel for an elastic element and a magnetic code plate for position detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the handle is mounted movably on the support to allow manual adjustment, then the actuator enables flexible control operation, but the handle exhibits play especially in the neutral position
Solution Approach 1:
The cam applies a preliminary clamping force to the handle in the neutral position before any user input occurs. This pre-loading action eliminates play by continuously pressing the handle against the cam surface, ensuring the handle is always in firm contact with the support structure even before the user grasps it.
Solution Approach 2:
The cam mechanism changes the contact parameters between the handle and support by transforming the clearanced fit into a pre-loaded contact. The elastic element modifies the force parameter, creating a continuous pressing force that eliminates the play while preserving the handle's ability to move when actuated by the user.
2Ease of manufacture
If clearance fits are used for bearing surfaces to simplify manufacturing, then manufacturing complexity is reduced, but handle vibrations and play increase
Solution Approach 1:
The invention converts the harmful effect of clearance fits (which cause vibrations and play) into a beneficial pre-loaded contact system. The cam mechanism transforms the loose clearance fit into a firm, vibration-free contact by applying continuous elastic force, thereby converting the manufacturing simplicity advantage into a performance disadvantage and reversing it.
3Manufacturing precision
If a cam mechanism is added to clamp the handle and reduce play, then handle stability is improved, but device complexity increases
Solution Approach 1:
The cam mechanism is merged with the existing support structure by integrating it into the connecting link. Rather than adding a separate, complex clamping device, the cam is combined with the universal joint components, eliminating the need for additional parts while achieving the play reduction function.
Solution Approach 2:
The cam mechanism serves multiple functions: it reduces handle play, provides a restoring force to return the handle to neutral position, and works together with the elastic element to maintain continuous contact. This multi-functionality reduces the need for separate components, thereby limiting the increase in device complexity.
4Ease of operation
If the handle is designed to pivot about multiple axes for ergonomic operation, then ease of operation is improved, but the number of moving parts and potential play increases
Solution Approach 1:
The cam applies a preliminary clamping force to the handle at the universal joint axes before operation. This pre-loading eliminates play at the pivot points, ensuring that the multi-axis pivoting motion is smooth and vibration-free while maintaining the ergonomic benefits of the universal joint configuration.
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 cam mechanism securely holds the handle in its zero position with minimal play, enhancing user ergonomics and reducing manufacturing tolerances' impact, resulting in a cost-effective and compact actuator suitable for confined vehicle spaces.
Implementation Method 1
a pressure element, guided in a cam track and subjected to an elastic force, interacts with the handle. This results in a restoring force acting on the handle, particularly in the direction of the neutral position, during adjustment.
Implementation Method 2
the means acting to clamp the handle is designed as a cam, the cam being located in the cam track. The cam is further located on a cam track wall of the cam track, opposite the cam track itself.
Implementation Method 3
the sensor can consist of a magnetic sensor, in particular several Hall sensors, in which a signal reversal occurs when the code plate is displaced.
Data Source
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AI summary
The invention relates to a control element (1), in particular a switching device, for manually controlling and/or activating functions in a motor vehicle, comprising a lever (2). Said lever (2) is mounted on a support (3) such that the lever (2) can be adjusted in at least one direction from a neutral position to an adjustment position. The lever (2) interacts with a pressure element (8) which is guided in a gate track (10) of a gate (9) and is resiliently loaded, in particular in such a way that a return force in the direction of the neutral position acts on the lever (2) when it is adjusted. A cam is present in the gate (9). Said cam, in the neutral position, acts upon the lever (2) in order to reduce play such that the lever (2) is biased in the direction towards the adjustment position.