Piezoelectric Linear Actuator for Vehicle Door Lock Noise Reduction
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Solution Overview
Problem
Conventional motor vehicle door locks with closing/opening devices generate significant structure-borne noise due to complex lever arrangements and large adjustment paths, which are transmitted into the passenger compartment, causing discomfort.
Innovation Solution
A motor vehicle door lock with a compact, low-weight electric motor driving a linear actuator, equipped with a gear system such as a worm gear, that operates a closing pawl with minimal noise through precise thread engagement, allowing flexible arrangement and reduced speed for increased torque, and optionally includes position sensors for precise control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a conventional electric motor with complex lever arrangement is used, then sufficient torque can be generated, but significant structure-borne noise is transmitted into the passenger compartment
Solution Approach 1:
The patent replaces the conventional electric motor with a piezoelectric stack actuator that converts electrical energy directly to mechanical displacement through the piezoelectric effect. This substitution eliminates the need for complex mechanical lever arrangements and significantly reduces structure-borne noise transmission into the passenger compartment.
Solution Approach 2:
The patent changes the operating parameters by using a piezoelectric actuator that operates at lower speeds with precise control, replacing the high-speed rotational motor. This parameter change reduces mechanical vibrations and noise while maintaining sufficient torque through the mechanical advantage of the lever system.
2Force
If a conventional electric motor with large adjustment path is used, then sufficient torque can be generated, but the device size and weight increase
Solution Approach 1:
The patent replaces the heavy conventional electric motor with a lightweight piezoelectric stack actuator. The piezoelectric material generates mechanical displacement directly when voltage is applied, eliminating the need for heavy rotating components, windings, and magnets, thus significantly reducing the weight of the closing/opening device.
Solution Approach 2:
The patent segments the actuation function into a compact piezoelectric stack that provides precise linear displacement. This segmented approach allows the use of smaller, lighter components while maintaining the required torque through the mechanical advantage of the lever arrangement and spindle mechanism.
3Force
If a conventional electric motor with large adjustment path is used, then sufficient torque can be generated, but the device dimensions increase
Solution Approach 1:
The patent replaces the conventional motor's large rotational adjustment path with a compact piezoelectric stack that provides precise linear displacement in a much shorter distance. The piezoelectric effect enables significant mechanical strain from minimal electrical input, reducing the required adjustment path length.
Solution Approach 2:
The patent transitions from the rotational motion of a conventional motor to linear displacement of a piezoelectric stack. This dimensional change allows the actuator to achieve the required torque through a compact linear path rather than a large rotational arc, reducing the overall device dimensions.
4Ease of operation
If a conventional electric motor is used, then the closing/opening function can be performed, but running noise is generated
Solution Approach 1:
The patent replaces the running conventional electric motor with a piezoelectric stack actuator that operates silently. The piezoelectric effect converts electrical voltage directly to mechanical displacement without rotating components, eliminating mechanical friction, brush noise, and magnetic field noise, thus achieving silent operation.
Solution Approach 2:
The patent changes the operating parameters by using a piezoelectric actuator that operates at very low speeds with precise control, replacing the high-speed rotational motor. This parameter change reduces mechanical vibrations and running noise while maintaining the closing/opening function.
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 significantly reduces noise during the closing/opening process by utilizing a linear drive with compact dimensions and low running noise, enabling efficient torque application without annoying sounds, and allows flexible integration within the vehicle door lock.
Implementation Method 1
the actuator is designed as a piezoelectric stack actuator which is acted upon by an electric field
Data Source
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AI summary
The present invention relates to a motor vehicle door lock, which is basically equipped with a locking mechanism (1, 2) and a closing/opening device (3 to 7) having a drive (3, 4, 5). The closing/opening device (3 to 7) works with the locking mechanism (1, 2) According to the invention, the drive (3, 4, 5) is configured as a linear drive (3, 4, 5).