Four-Link Wiper Arm Layout for Extended Windshield Coverage
Solution Overview
Problem
Existing vehicle wiper devices struggle to effectively increase the wiping area for both the front and rear windshields, especially when the front windshield has a long length dimension in the longitudinal direction, leading to inefficiencies such as increased overlapping regions or unwiped areas.
Innovation Solution
A vehicle wiper device with a single wiper arm incorporating a link mechanism with four nodes, where the fulcrum is positioned near the wiper blade on the power input side, and the rotation direction of the drive shaft and wiper arm are aligned, allowing the wiper blade to be pushed towards the upper region of the windshield during operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the length of the wiper blade on the driver's seat side is increased to increase the wiping area, then the wiping area increases, but the overlapping portion between the driver's seat side wiper blade and passenger's seat side wiper blade increases, leading to deterioration in wiping efficiency
Solution Approach 1:
The invention divides the windshield into two distinct wiping zones: the driver's seat side windshield wiping zone and the passenger's seat side windshield wiping zone. By providing separate wiper blades for each zone with dedicated driving mechanisms, the system eliminates overlapping portions while ensuring complete coverage of the entire windshield surface, thus resolving the contradiction between increasing wiping area and maintaining wiping efficiency
2Device complexity
If only one wiper arm is provided to reduce the number of parts, then the number of parts is reduced, but the wiping area cannot be increased for the entire front windshield
Solution Approach 1:
The single wiper arm is segmented into two functional units: a driver's seat side wiper blade and a passenger's seat side wiper blade, each capable of independent operation. This segmentation allows the system to maintain simplicity (single arm structure) while achieving extended wiping coverage across the entire windshield
Solution Approach 2:
The single wiper arm structure is designed to perform multiple functions: it can independently control the driver's seat side wiper blade for one wiping zone and the passenger's seat side wiper blade for another wiping zone. This multi-functionality enables the system to achieve comprehensive windshield coverage without requiring separate wiper arms for each zone
3Adaptability or versatility
If the length dimension of the front windshield in the longitudinal direction increases due to small inclination angle, then aerodynamic characteristics and design properties are improved, but the wiping area to the upper portion of the front windshield cannot be reached
Solution Approach 1:
The invention extends the wiping capability into the longitudinal dimension of the windshield by positioning the driver's seat side wiper blade to reach the upper portion of the windshield. The link mechanism enables the wiper blade to traverse the extended longitudinal distance, ensuring that the increased windshield length (resulting from small inclination angle) is fully covered
4Shape
If the link mechanism is intended to bring the wiper blade closer to being parallel to the vertical frame at the upper reversing position, then the wiper blade alignment is improved, but the wiping area is not increased
Solution Approach 1:
The link mechanism is designed not only to achieve proper wiper blade alignment parallel to the vertical frame but also to extend the wiping area in the longitudinal dimension. By optimizing the link lengths and arrangement, the mechanism enables the wiper blade to reach the upper portion of the windshield while maintaining correct alignment at the reversing position
Data Source
AI summary
In a vehicle wiper device having a wiper arm rotatably supported by a vehicle body and a wiper blade supported by the wiper arm, the wiper arm includes a link mechanism of 4 nodes, a fulcrum located closer to the wiper blade in the link mechanism is located on a side opposite to the wiper blade than a position of a hinge of the wiper arm, and when the wiper blade is at a lower end of a windshield, an arm connected to a drive shaft of each arm constituting the link mechanism is disposed below the drive shaft, and a rotation direction of the drive shaft and a rotation direction of the wiper arm are the same direction.