Automotive Starter Control Lever Kinematics for Cold Start Reliability
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Solution Overview
Problem
Existing electric engine starters with internal combustion face challenges in efficiently deactivating the starter contactor when the launcher blocks in the active position, particularly at low temperatures where the lubricant freezes, leading to potential blocking of the Z cold function.
Innovation Solution
The solution involves distributing the cut-off game across the movement of the pivoting axis and the skate, allowing the variable game between the skate and the launcher to reduce the amplitude of the displacement of the pivoting axis of the control lever, thereby accumulating kinetic energy in the mobile nucleus of the contactor to prevent blocking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the cut-off clearance is provided entirely by the pivot axis movement, then the contactor can be electrically deactivated, but the moving core cannot accumulate sufficient kinetic energy to prevent Z-function jamming at low temperatures
Solution Approach 1:
The cut-off clearance is segmented into two components: a first clearance component provided by the pivot axis movement and a second clearance component provided by the variable pad clearance. This segmentation allows the moving core to travel a shorter distance while still achieving the necessary kinetic energy accumulation and contactor deactivation.
Solution Approach 2:
The variable pad clearance is pre-configured to provide the second clearance component, enabling the moving core to accumulate kinetic energy during a reduced free travel distance. This preliminary arrangement of the pad clearance geometry ensures that the required kinetic energy is achieved before the contactor needs to be deactivated.
2Reliability
If the free travel distance of the moving core is increased to accumulate kinetic energy, then Z-function jamming is prevented, but the cut-off clearance required for contactor deactivation increases
Solution Approach 1:
The total clearance requirement is segmented between the pivot axis movement (first clearance component) and the variable pad clearance (second clearance component). This allows the moving core to accumulate kinetic energy over a shorter distance while the pivot axis provides additional clearance for contactor deactivation.
Solution Approach 2:
The control lever acts as an intermediary mechanism that translates the moving core's limited travel into sufficient cut-off clearance through its pivot axis movement. The variable pad clearance works in conjunction with the control lever to achieve both kinetic energy accumulation and contactor deactivation within a compact space.
3Reliability
If the variable pad clearance is reduced to minimize free travel, then kinetic energy accumulation is improved, but the cut-off clearance for contactor deactivation becomes insufficient
Solution Approach 1:
The cut-off clearance is segmented into a first component from pivot axis movement and a second component from variable pad clearance. This segmentation allows optimization of kinetic energy accumulation while maintaining sufficient total clearance for reliable contactor deactivation.
Solution Approach 2:
The pad clearance is designed as variable rather than fixed, allowing it to dynamically adjust during operation. This dynamic characteristic enables the system to provide the necessary second clearance component for contactor deactivation while maintaining a reduced average clearance that promotes kinetic energy accumulation.
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 approach reduces the risk of blocking the Z cold function by ensuring the mobile nucleus of the contactor accumulates sufficient kinetic energy, while maintaining a constant or increasing lever ratio, thus enhancing the gable kinematics and reducing the risk of stalling.
Implementation Method 1
It is important for the contactor's moving core to accumulate kinetic energy to prevent any risk of the Z function jamming when cold
Implementation Method 2
a control lever (27) having a pivot axis (50) which is movable over a predetermined linear stroke... a skate (25) having a shape arranged to obtain a lever ratio of the control lever on the launcher, a ratio which is constant or increasing
Implementation Method 3
a pivot axis (50) which is movable over a predetermined linear stroke from a rest position to a lever support position
Data Source
Figure 1
Figure 2~4
Figure 5
AI summary
The invention relates to an electric starter (1) of an internal combustion engine, specifically a starter of an internal combustion engine of a motor vehicle, said starter comprising: a starter drive assembly (19) mobile between an inoperative position and an operative position in which the starter drive assembly is capable of starting the internal combustion engine; an electric motor (45) capable of rotating the starter drive assembly about an axis of rotation (X); a control lever (27) arranged so as to move the starter drive assembly axially, the control lever being capable of pivoting about a pivoting axis (50), said pivoting axis being movable over a predetermined linear stroke from an inoperative position to a lever pressing position in which the lever can pivot so as to bring the starter drive assembly into the operative position, said control lever including at least one block (25) arranged such as to engage with the starter drive assembly.