Starter Pinion Meshing Timing for Engine Start/Stop Noise Reduction
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Solution Overview
Problem
Existing start/stop operations for internal combustion engines in vehicles result in increased noise and wear due to the meshing of the starter pinion with the ring gear at varying rotational speeds during coasting, which affects vehicle comfort and reliability.
Innovation Solution
Determining a specific point in time for meshing the starter pinion with the ring gear when the internal combustion engine is at a constant coasting rotational speed, using precalculated characteristic rotational speed values to minimize the rotational speed difference between the starter pinion and ring gear, and optimizing the meshing process around ignitable top dead centers to reduce noise and wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the starter pinion is meshed with the ring gear during coasting of the internal combustion engine, then the engine can be restarted, but noise and wear increase due to rotational speed differences between the starter pinion and ring gear
Solution Approach 1:
The controller determines a specific meshing point in time before actual meshing occurs, selecting a moment when the rotational speed of the coasting engine is constant or changes minimally. This preliminary timing selection ensures that when the starter pinion engages the ring gear, the rotational speed difference is minimized, thereby reducing noise and wear while maintaining reliable meshing operation
Solution Approach 2:
The invention changes the temporal parameter of the meshing operation by selecting a specific point in time during coasting when rotational speed is stable. By monitoring rotational speed variations and identifying a meshing point where speed change is minimal, the system optimizes the meshing conditions to reduce harmful effects while ensuring successful engine restart
2Loss of time
If the starter pinion is meshed immediately after shutdown, then restart time is reduced, but noise and wear increase due to varying rotational speed during coasting
Solution Approach 1:
The controller performs preliminary analysis of the coasting rotational speed profile to identify an optimal meshing point in time. By pre-determining when rotational speed will be most stable during the coasting phase, the system can initiate meshing at the optimal moment, balancing minimal restart time with reduced noise and wear from speed-matched engagement
3Reliability
If the rotational speed of the ring gear and starter pinion are matched during meshing, then wear is reduced, but the complexity of control increases
Solution Approach 1:
The system utilizes the natural coasting behavior of the internal combustion engine, which automatically produces periods of constant rotational speed. The controller simply detects and responds to these naturally occurring stable speed periods, rather than actively controlling the engine speed. This self-service approach achieves rotational speed matching with minimal control complexity
Solution Approach 2:
The invention monitors the rotational speed parameter during coasting and identifies specific time points where the speed parameter is stable. By changing the control strategy from active speed regulation to passive detection of stable speed periods, the system reduces control complexity while achieving the benefit of matched rotational speeds for durable meshing
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 solution reduces noise and wear during the meshing process, enhances the reliability of the meshing operation, and improves vehicle comfort by ensuring a consistent rotational speed, thereby improving the start/stop mode efficiency and reducing electrical power consumption.
Implementation Method 1
a starter motor (8) having a starter pinion (9) for meshing with a ring gear (6) of an internal combustion engine (1)
Implementation Method 2
the rotational speed and position of a crankshaft (2) of the internal combustion engine (1) being detected with the aid of a detector device (4)
Data Source
AI summary
In a method for controlling a start/stop operation of an internal combustion engine in a motor vehicle, the controller activates a starting device which has a starter motor and a meshing device for the purpose of starting the internal combustion engine and of executing a start/stop operation, the rotational speed and position of a crankshaft of the internal combustion engine being detected with the aid of a detector device. To provide vehicle comfort in start/stop mode and to implement meshing of a starter pinion with the ring gear at a coasting rotational speed at reduced noise and wear, a point in time is determined for meshing with the ring gear of a coasting internal combustion engine after the internal combustion engine has been shut down.