Hatch Drive Torsion Bar Torque Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Drive devices for hatches, particularly tailgates, are uncomfortable to operate manually due to the heavy weight of the tailgate, especially when closing, and existing solutions do not adequately address the force required to open the hatch against gravity in downhill positions.
Innovation Solution
A drive device comprising a cable pulley system with a torsion bar that applies torque in specific directions to facilitate the opening and closing of the hatch, supported by a first and second superordinate assembly, and includes a unidirectional clutch and coil spring to manage cable tension and rotation, allowing for easier operation and reduced load on bearing components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the hatch is closed manually, then the operator can control the closing process, but the heavy weight of the tailgate makes it uncomfortable to operate
Solution Approach 1:
The torsion bar is configured to generate a counter-torsional moment that opposes the gravitational force acting on the hatch. This counter-moment acts as a mechanical counterweight system, reducing the net force the operator must exert to close the heavy tailgate, thereby improving ease of operation without changing the actual weight of the hatch.
Solution Approach 2:
The torsion bar serves as an intermediary mechanical element between the operator's input force and the hatch movement. It transmits and transforms the applied force through torsional deformation, providing mechanical advantage and making the heavy hatch easier to manipulate during the closing process.
2Ease of operation
If the torsion bar applies torque throughout the entire movement range, then the hatch can be supported during closing, but the force with which the hatch reaches the end point of the movement range increases excessively
Solution Approach 1:
The torsion bar is configured to provide torque only in specific zones of the movement range rather than uniformly throughout. By applying torque locally where needed (during the closing process) and reducing it near the end point, the system optimizes support effectiveness while minimizing excessive force at critical positions.
Solution Approach 2:
Instead of applying torque across the entire movement range, the torsion bar implements partial action by providing torque only over specific portions of the rotation. This prevents over-application of force at the end point while still providing sufficient support during the main closing phase, achieving the desired effect with controlled, partial torque application.
3Adaptability or versatility
If the hatch is opened against gravity in downhill positions, then the hatch can be opened in various orientations, but the force required to open the hatch increases
Solution Approach 1:
The torsion bar generates a counter-torsional moment that compensates for the gravitational torque that varies with the hatch's orientation. This allows the system to adapt to different positions (including downhill orientations) by dynamically opposing the gravity-induced torque, thereby maintaining operability across various orientations without requiring excessive opening force.
4Stability of the object's composition
If the torsion bar is rigidly fixed, then the structural stability is improved, but the ability to move between different states (closed and maximally open) is reduced
Solution Approach 1:
The torsion bar is configured as a dynamic element that can rotate and change its torsional state as the hatch moves between closed and maximally open positions. This dynamic capability allows the bar to maintain structural integrity while adapting to different angular positions, providing both stability during operation and versatility across the full movement range.
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 enables comfortable operation of the hatch by supporting the closing process and reducing the force required to open the hatch, especially in downhill positions, thereby minimizing the load on vehicle components and ensuring smooth operation across various angles.
Implementation Method 1
a torsion bar which is configured to generate a corresponding counter-torsional moment upon input of a torsional force into the torsion bar
Implementation Method 2
a cable pulley, which is configured to wind or unwind the cable according to the direction of rotation of the cable pulley
Data Source
AI summary
The present invention relates to a drive device, comprising a cable which is connected at one end to a cable pulley, an actuator for driving the cable pulley, and a torsion bar which generates a torsional moment, wherein the torsion bar is supported on a higher-level assembly in such a way that it can move between a first and a second state of the torsion bar, wherein the torsion bar applies a torque in a first direction over a first partial movement range, applies a torque in a second direction opposite to the first direction over a second partial movement range, and does not apply torque over a third partial movement range. The present invention also relates to a superordinate hatch arrangement.