Motor Vehicle Lock DC Motor Circuit Noise Reduction
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Solution Overview
Problem
Existing vehicle door lock systems with electric closing drives face issues of durability and convenience due to excessive motor load and noise generation during the reset process, particularly when no clutch is provided, leading to undesirable tension and noise development.
Innovation Solution
A motor vehicle door lock system utilizing a DC motor with coupling means like a worm drive and Bowden cable, coupled with mechanical restoring springs, and an enhanced motor circuit featuring protective diodes, Zener diodes, and varistors to manage rotational speed and voltage, reducing noise and wear by implementing engine braking and voltage limiting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the electric motor is used to drive the closing action of the locking element, then the locking element can be moved into the locked position against seal force or friction, but the motor becomes rotationally fixed during the return process and operates as a generator, causing excessive voltage generation and noise
Solution Approach 1:
A clutch mechanism is introduced as an intermediary between the electric motor and the locking element. The clutch disengages the motor from the locking element during the return process, preventing the motor from being rotationally fixed and operating as a generator, thereby eliminating excessive voltage generation and noise while maintaining motorized closing capability
2Duration of action of moving object
If the motor is rotationally fixed to the returned elements via a chain of actions, then the return to original position is achieved, but the motor acts as a generator creating considerable voltage and undesirable noise
Solution Approach 1:
The clutch mechanism extracts or separates the motor from the return motion path. During the return process, the clutch disengages, allowing the locking element to return to its original position independently without rotating the motor, thereby eliminating the generator effect and associated noise and voltage peaks
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 system enhances durability and convenience by reducing noise and wear, ensuring reliable operation and efficient reset of the locking mechanism while minimizing voltage peaks and motor stress.
Implementation Method 1
DC electric motor to provide a closing aid
Implementation Method 2
mechanical restoring means are coupled to the coupling means, exerting a preload force on the coupling means in the direction of the initial position
Implementation Method 3
at least one protection diode and at least one discrete component connected in series with it, this discrete component comprising an ohmic resistor or a Zener diode with reverse bias
Implementation Method 4
varistors to manage rotational speed and voltage
Data Source
Figure 1~2c
Figure 3~4
AI summary
A door lock for a motor vehicle, comprising a blocking means (3) which is coupled to an electric DC motor (7) for providing a locking aid, wherein coupling means (8, 9, 12) are provided for converting the rotary movement of the DC motor into a blocking movement. The DC motor (7) moves the coupling means from a starting position to a pulled-closed position. Mechanical resetting means exert a prestressing force onto the coupling means in the direction of the starting position. When the supply of voltage to the DC motor (7) is stopped, the resetting means resets the coupling means to the starting position, wherein the resetting of the coupling means is converted into a voltage-generating movement of the DC motor (7). An electrical circuit for driving the DC motor has a first path with discrete components parallel to the DC motor (7), wherein the first path has at least one protection diode (26) and at least one discrete component, which is connected in series with said protection diode, in the form of a non-reactive resistor (27) and/or a Zener diode (28).