Vehicle Seat Load Sensor Parallelogram Linkage for Assembly Error Absorption
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional passenger weight measurement devices for vehicle seats face challenges in accurately measuring weight due to dimension and assembling position errors, which apply initial loads to load sensors, and also suffer from unnecessary force interference with load cells, leading to inaccurate measurements.
Innovation Solution
The solution involves a passenger weight measurement device with a pair of slide rails and load cells arranged at four corners, where two load sensors on one diagonal line are movable to absorb distortions, and the other two are fixed, creating a rigid frame structure that prevents initial load application and maintains accurate weight measurement. This structure includes a leaf spring mechanism to secure the load sensors and absorb errors, ensuring precise weight detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a load sensor is disposed between the vehicle floor and the vehicle seat, then the passenger's weight can be measured, but dimension error or assembling position error occurs causing initial load to be applied to the load sensor, reducing measurement accuracy
Solution Approach 1:
The patent employs a parallelogram linking mechanism that allows dynamic adjustment and absorption of dimensional and positional errors during assembly. The mechanism includes movable links and joints that can accommodate variations in assembly dimensions, preventing these errors from being transmitted as initial loads to the load sensor, thereby maintaining measurement accuracy despite manufacturing tolerances.
Solution Approach 2:
The load sensor is not directly connected between the vehicle floor and seat, but rather is incorporated into a parallelogram linking mechanism that acts as an intermediary. This mechanism includes multiple links and joints that mediate the force transmission, isolating the load sensor from direct dimensional and positional errors while still allowing accurate weight measurement.
2Ease of operation
If a parallelogram linking mechanism is disposed between the pair of slide rails and the seat bracket, then the seat weight measurement can be facilitated, but the number of components increases and the height from the vehicle body floor to the seat cushion becomes difficult to control
Solution Approach 1:
The parallelogram linking mechanism serves multiple functions simultaneously: it transmits seat weight to the load sensor, accommodates assembly dimensional errors, maintains structural rigidity, and enables the seat to slide along the rails. By integrating these functions into a single mechanism, the patent avoids the need for separate components for each function, thereby reducing overall complexity despite the mechanism's sophisticated design.
3Device complexity
If compression type load cells are disposed between the pair of slide rails and the pair of side frames, then the configuration is simplified and height restrictions are eliminated, but unnecessary force is applied on the load cell interfering with passenger load measurement
Solution Approach 1:
The patent applies different connection characteristics to different parts of the system. The parallelogram linking mechanism uses movable joints and links with specific degrees of freedom at different locations, allowing certain parts to be rigid while others remain flexible. This local differentiation enables the system to maintain simplicity while preventing unnecessary forces from being applied to the load cells, as the mechanism selectively transmits only the relevant weight forces.
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 proposed solution effectively suppresses initial load generation during assembly, maintains load sensor rigidity, and prevents unnecessary force interference, thereby enhancing the accuracy of passenger weight measurement while maintaining the conventional seat structure's integrity.
Implementation Method 1
a leaf spring mechanism to secure the load sensors and absorb errors
Data Source
AI summary
A passenger's weight measurement device for a vehicle seat, capable of suppressing generation of an initial load, has a pair of slide rails extending in parallel and fixed to the vehicle floor, and a pair of side frames that support the seat and are disposed above the pair of slide rails. Load cells are disposed between the pair of the slide rails and the pair of the side frames. A set of first connection frames for connecting both ends of the pair of side frames extend in parallel to be perpendicular to the pair of side frames. Second and third connecting frames connect middle parts of the pair of slide rails so as to be perpendicular to the slide rails. The pair of the slide rails and the second and a third connecting frames constitute an H-shaped frame. The load cells include an elastic member having a varied-diameter portion.