Electromechanical Parking Lock with Spring-Triggered Redundancy
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Solution Overview
Problem
Existing parking lock devices for vehicle transmissions, particularly in electric drive units, lack efficient electromechanical actuation and redundant safety mechanisms, leading to potential unintentional vehicle rolling on slopes due to the absence of hydraulic pressure supply and limited functional reliability.
Innovation Solution
A compact parking lock device with electromechanical actuation using a first actuator and a second actuator, featuring a rotary mechanism with a latching mechanism, insert spring, and permanent magnet, allowing for automatic functional testing and redundant operation, along with a position sensor and control device for reliable locking and unlocking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hydraulic actuation is used for parking lock, then reliable locking can be achieved, but it cannot be applied to electric drive units without hydraulic pressure supply
Solution Approach 1:
The patent replaces the hydraulic actuation system with an electromechanical actuation system. The electric motor directly drives the parking lock mechanism through a reduction gear and cam mechanism, eliminating the need for hydraulic pressure supply while maintaining reliable locking capability in electric drive units.
Solution Approach 2:
The patent eliminates the hydraulic actuation system entirely in favor of an electromechanical system, making the parking lock adaptable to electric drive units that lack hydraulic pressure supply.
2Reliability
If single actuator is used for parking lock, then device complexity is reduced, but functional reliability and safety are compromised
Solution Approach 1:
The control device performs preliminary functional tests of the electric motor during normal operation by attempting to engage and disengage the parking lock. This preliminary testing ensures the actuator is functioning correctly before relying on it for actual parking lock operations, enhancing reliability without requiring redundant actuators.
Solution Approach 2:
The single electric motor actuator performs self-testing and self-validation through automated functional tests controlled by the control device. The system monitors its own operational status and can detect malfunctions, allowing a single actuator to provide both the primary function and reliability verification.
3Ease of manufacture
If compact design is implemented, then ease of assembly is improved, but space for redundant components is limited
Solution Approach 1:
The control device performs preliminary functional tests of the electric motor during normal operation by attempting to engage and disengage the parking lock. This preliminary testing ensures the actuator is functioning correctly before relying on it for actual parking lock operations, enhancing reliability without requiring redundant actuators.
Solution Approach 2:
The single electric motor actuator performs self-testing and self-validation through automated functional tests controlled by the control device. The system monitors its own operational status and can detect malfunctions, allowing a single actuator to provide both the primary function and reliability verification.
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 provides enhanced safety by ensuring the parking lock can engage and disengage reliably, reducing the risk of unintentional vehicle rolling through automatic actuator redundancy and efficient electromechanical operation, even in the absence of hydraulic pressure.
Implementation Method 1
a position sensor arranged in a detection area of the permanent magnet, wherein the position sensor is configured to detect a movement of the permanent magnet relative to the position sensor
Implementation Method 2
a rotary mechanism, which is connected to the drive shaft and comprises a detent mechanism, an insert spring, and a permanent magnet, wherein the rotary mechanism can be pretensioned via the insert spring
Implementation Method 3
a drive shaft and a first actuator, by means of which the drive shaft is rotatable
Implementation Method 4
a second actuator, by means of which, when the insert spring is pretensioned, the detent mechanism can be triggered and the locked position can thereby be engaged by a force effect of the insert spring on the rotary mechanism
Data Source
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AI summary
The invention relates to parking brake device (10) for a vehicle transmission (GT) comprising a driveshaft (AW) and a first actuator (F1), via which the driveshaft (AW) can be rotated; a pawl (2), which can be lockingly engaged in the vehicle transmission (GT); a rotary mechanism (1), which is connected to the driveshaft (AW) and comprises an engaging mechanism, an insert spring (16) and a permanent magnet (PM), wherein the pawl (2) and the rotary mechanism (1) can be moved with the permanent magnet (PM) between a locking position (P) and a neutral position (nP) for the vehicle transmission (GT), wherein the rotary mechanism (1) can be pretensioned via the insert spring (16) and the neutral position (nP) can be adopted; wherein the parking brake device (10) also comprises: a second actuator (F2), via which the engaging mechanism can be triggered when the insert spring (16) is pretensioned and, as a result, the locking position (P) can be entered via an application of force of the insert spring (16) on the rotary mechanism.