Lock-up Device Dynamic Damper Inhibits Secondary Resonance
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Solution Overview
Problem
Existing lock-up devices for torque converters face challenges in effectively inhibiting rotational speed variation across wide ranges due to manufacturing errors and secondary resonance, which affects the dynamic damper's ability to attenuate rotation effectively and maintain low fuel consumption.
Innovation Solution
A lock-up device configuration that includes a dynamic damper device coupled to an intermediate member, with a series-like arrangement of elastic members and a hysteresis torque generating mechanism, which adjusts hysteresis torque based on rotational speed ranges to prevent relative rotation and inhibit vibration, even when manufacturing errors occur.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the locking rotational speed is set to a fixed value, then the dynamic damper can attenuate rotation effectively at that specific speed, but manufacturing errors cause the actual locking speed to vary, reducing the effectiveness across wide rotational speed ranges
Solution Approach 1:
The patent makes the locking rotational speed variable by introducing a second hysteresis torque that activates at higher rotational speeds. The hysteresis torque generating mechanism dynamically adjusts the locking speed based on operating conditions, allowing the system to adapt to manufacturing errors and maintain effectiveness across wide rotational speed ranges rather than being fixed at a single speed value
Solution Approach 2:
The patent changes the hysteresis torque parameter based on rotational speed ranges. A first hysteresis torque operates in low to middle speed ranges, while a second hysteresis torque larger than the first is generated in middle to high speed ranges. This parameter change allows the system to maintain effective locking across varying operational conditions despite manufacturing variations
2Device complexity
If a single hysteresis torque is generated across all rotational speeds, then the structure is simpler, but it cannot effectively attenuate rotation variation across wide rotational speed ranges
Solution Approach 1:
The patent applies different hysteresis torque characteristics to different rotational speed ranges. The first hysteresis torque is optimized for low to middle speed ranges, while the second hysteresis torque is optimized for middle to high speed ranges. This local differentiation ensures effective rotation attenuation across the entire operational spectrum without requiring complete redesign for each speed range
Solution Approach 2:
The hysteresis torque generating mechanism dynamically switches between first and second hysteresis torques based on rotational speed. This dynamic behavior allows a single mechanism to provide appropriate torque characteristics for different operating conditions, maintaining reliability without proportionally increasing structural complexity
3Device complexity
If the inertia member is not locked with the output member in high rotational speed range, then the mechanism is simpler, but variation in output-side rotational speed cannot be inhibited
Solution Approach 1:
The patent implements a dynamic locking mechanism where the inertia member is locked with the output member in the high rotational speed range through the second hysteresis torque. This dynamic locking ensures stability when needed (high speeds) while allowing freedom of movement when not needed (lower speeds), maintaining simplicity without sacrificing stability
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
This configuration effectively inhibits rotational speed variation across wide ranges, preventing secondary resonance and ensuring low fuel consumption by optimizing hysteresis torque generation and torsion angle, thereby enhancing the dynamic damper's performance.
Implementation Method 1
a plurality of elastic members which elastically couple the input rotary member and the output rotary member in a rotational direction
Implementation Method 2
a hysteresis torque generating mechanism configured to generate a first hysteresis torque in a low rotational speed range and generate a second hysteresis torque larger than the first hysteresis torque in middle to high rotational speed ranges
Implementation Method 3
the dynamic damper device includes an inertia member coupled to the intermediate member
Data Source
AI summary
Occurrence of secondary resonance in a dynamic damper device of a lock-up device is inhibited to improve effectiveness of the dynamic damper device. The lock-up device includes a drive plate, a driven plate coupled to a turbine, an intermediate member, a plurality of outer peripheral side and inner peripheral side torsion springs, and a dynamic damper device. The intermediate member is disposed between the outer peripheral side torsion springs and the inner peripheral side torsion springs. The outer peripheral side torsion springs elastically couple the drive plate and the intermediate member in a rotational direction. The inner peripheral side torsion springs elastically couple the intermediate member and the driven plate in the rotational direction. The dynamic damper device includes an inertia ring coupled to the intermediate member.