Wiper Blade Lip Direction Control for Cold Region Durability
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Solution Overview
Problem
Conventional wiper apparatuses face issues with plastic deformation of wiper blade rubber due to frequent direction changes, especially in cold regions, leading to reduced wiping performance, as the short travel distance for direction change is insufficient to prevent bending propensity.
Innovation Solution
A wiper apparatus that changes the direction of the wiper blade's lip based on specified stop positions, including a first stop position, a second stop position, a lower limit position, and an upper limit position, with temporary movements to these positions triggered by vehicle speed detection, ensuring a longer travel distance and reducing the need for frequent direction changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the wiper blade frequently changes direction at close stop positions, then the lip direction changes to suppress plastic deformation, but the travel distance is too short to effectively prevent bending in cold regions
Solution Approach 1:
The patent introduces a new spatial dimension by adding limit positions beyond the traditional first and second stop positions. The wiper blade travels from a stop position to a limit position (lower or upper) and then returns, creating an extended travel path in the vertical dimension that ensures sufficient movement distance for preventing lip bending, even in cold conditions.
2Reliability
If the wiper blade changes direction frequently to prevent plastic deformation, then the lip orientation varies, but this causes increased wear and reduced durability
Solution Approach 1:
The patent implements periodic direction changes only when specific conditions are met (when the wiper blade stops at the first or second stop positions). The control unit periodically reverses the wiper motor's rotation direction, causing the wiper blade to travel to limit positions and return, thereby periodically changing the lip direction to prevent plastic deformation while maintaining durability through controlled, conditional action.
3Adaptability or versatility
If the wiper motor rotates in both normal and reverse directions to change lip direction, then the front end side of the lip faces different directions, but this complex control reduces operational simplicity
Solution Approach 1:
The control unit monitors the wiper motor's rotation direction and the wiper blade's position at stop positions. When the wiper blade stops at the first stop position with the lip facing upward, the control unit detects this state and automatically reverses the motor direction. Similarly, when the lip faces downward at the second stop position, the control unit triggers a direction reversal, creating a feedback-based automatic control system that adapts to the wiper blade's state.
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 effectively prevents plastic deformation and maintains wiping performance by ensuring the wiper blade's lip can certainly change direction at predetermined stop positions, reducing the bending propensity and eliminating the need for frequent direction changes, thus enhancing the durability and effectiveness of the wiper apparatus.
Implementation Method 1
a blade rubber whose lip is pressed to the surface by the spring force of a tensile spring disposed on the base end of the wiper arm
Implementation Method 2
the lip comes in sliding contact with a windshield
Data Source
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AI summary
When the number of times of vehicle speed detections reaches a prescribed times "n", a DR-side wiper blade is moved in such a way that when the front end side of a lip reaches a lower-side stop position APS1, the DR-side wiper blade is temporarily moved to a lower limit position for stop EPSL, then moved to an upper-side stop position APS2 and stopped there, and in such a way that when the front end side of the lip reaches an upper-side stop position APS2, the DR-side wiper blade is moved temporarily to an upper limit position for stop EPSU, then moved to the lower-side stop position APS1 and stopped there.