Steering Device Operation Lever Rattling Reduction
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Solution Overview
Problem
In steering devices where the nut and operation lever are disposed on the same side relative to the bracket, it is difficult to couple the tightening shaft to the operation lever due to a great distance, leading to rattling issues.
Innovation Solution
A steering device design that includes a steering column supported by brackets with a tightening shaft penetrating these brackets, a nut attached to the shaft, an operation lever between the nut and the bracket, and a coil spring contacting the bottom surface of the case and the tightening shaft, which pulls the operation lever toward the nut, reducing rattling. Additional features such as small diameter portions in the case and an inclined surface on the tightening shaft help maintain the coil spring's axial alignment and reduce friction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the nut and operation lever are disposed on the same side relative to the bracket, then the structure is simplified and easier to manufacture, but the distance from the operation lever to the tip of the tightening shaft becomes great, making it difficult to couple them using the coupling member
Solution Approach 1:
The patent introduces a coil spring as an intermediary coupling member between the tightening shaft and the operation lever. The coil spring can be compressed and expanded to accommodate the great distance when the nut and operation lever are on the same side, enabling effective coupling while maintaining the simplified single-side structure.
Solution Approach 2:
The patent changes the physical state and mechanical properties of the coupling member by using a coil spring instead of a rigid coupling. The spring constant and elasticity of the coil spring allow it to adapt to varying distances, enabling coupling effectiveness despite the increased distance from the operation lever to the tightening shaft tip.
2Adaptability or versatility
If the distance from the operation lever to the tip of the tightening shaft is great, then the nut and operation lever can be disposed on the same side, but it becomes difficult to couple the tightening shaft to the operation lever using the coupling member
Solution Approach 1:
The coil spring acts as a mediator that bridges the gap between the tightening shaft and operation lever, maintaining reliable coupling even when the distance is great. The spring's elastic properties ensure continuous contact and force transmission, preserving coupling reliability regardless of the increased distance.
Solution Approach 2:
The patent employs a dynamic coupling mechanism using a coil spring that can adapt its length and stiffness to the specific distance between components. This dynamic adjustment capability ensures reliable coupling whether the distance is short or great, accommodating various assembly conditions while maintaining coupling effectiveness.
3Strength
If a rigid coupling member is used to connect the tightening shaft and operation lever, then the coupling is strong, but it causes rattling of the operation lever in the unlocked state
Solution Approach 1:
The patent changes the mechanical parameters of the coupling member by using a coil spring with specific elastic properties. This allows the coupling to maintain sufficient strength for torque transmission while introducing compliance that absorbs vibrations and prevents rattling of the operation lever in the unlocked state.
Solution Approach 2:
The coil spring provides beforehand cushioning by absorbing shocks and vibrations before they can cause rattling. The elastic deformation of the spring cushions the impacts and prevents the operation lever from rattling, while still maintaining strong coupling for normal operation.
4Ease of operation
If the coil spring has a small spring constant to easily couple the tightening shaft and operation lever, then the coupling is easy to achieve, but it may not provide sufficient pulling force to reduce rattling
Solution Approach 1:
The patent applies partial action by using a coil spring with a small spring constant that provides just enough pulling force to reduce rattling without being excessively strong. This allows easy coupling while achieving the necessary force to pull the operation lever toward the nut and eliminate rattling, avoiding the problems of overly strong springs.
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 design effectively reduces rattling of the operation lever even when the nut and operation lever are on the same side relative to the bracket, allowing for easier coupling of the tightening shaft and operation lever, and minimizes abnormal noise from friction and contact.
Implementation Method 1
a coil spring coming into contact with the bottom surface and the tightening shaft
Implementation Method 2
the coil spring can easily have a small spring constant
Implementation Method 3
The coil spring presses the tightening shaft and the case with appropriate force
Implementation Method 4
minimizes abnormal noise from friction and contact
Data Source
AI summary
A steering device including a steering column supporting a steering shaft to be coupled to a steering wheel. The steering column is sandwiched between a bracket including a first support plate and a second support plate with a tightening shaft penetrating the first support plate and the second support plate and including a male thread at an end of the tightening shaft on a side close to the second support plate having a nut attached thereon. An operation lever is disposed between the nut and the second support plate and penetrated by the tightening shaft. A case including a bottom surface facing an end surface of the tightening shaft is attached to the operation lever, and a coil spring coming into contact with the bottom surface and the tightening shaft.