Actuator Case Reinforcing Ribs Weld Line Strength
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Solution Overview
Problem
Actuators used in adverse environments, such as undercarriages of vehicles, face challenges with weld lines formed during injection molding, which can lead to weakened structures and reduced strength, making them susceptible to shocks and environmental exposures.
Innovation Solution
The actuator design incorporates reinforcing ribs and a specific manufacturing method that thickens the material thickness at weld lines, and strategically places convex portions to avoid stress concentrations, enhancing the structural integrity and reliability of the case.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If injection molding is used to form the case, then manufacturing efficiency and cost are improved, but weld lines are formed which reduce the strength of the case
Solution Approach 1:
The patent applies local quality by providing reinforcing ribs at specific locations where weld lines are expected to form. These reinforcing ribs locally increase the thickness and strength of the case at critical areas without affecting the overall manufacturing process or adding excessive weight to the entire structure.
Solution Approach 2:
The patent employs preliminary action by designing the reinforcing ribs into the mold cavity before injection molding occurs. This allows the weld line weakness to be compensated for in advance, ensuring that even though weld lines will form during manufacturing, the case strength at those locations is pre-reinforced to meet required specifications.
2Weight of moving object
If the case is made thinner to reduce weight, then lightness is improved, but strength and resistance to external shocks are reduced
Solution Approach 1:
The patent uses local quality by making the case wall thickness non-uniform, with thinner walls in non-critical areas to reduce weight, and thicker reinforced sections at weld line locations and high-stress areas to maintain shock resistance. This allows optimization of weight while ensuring structural integrity where needed.
Solution Approach 2:
The patent applies dimensionality change by adding reinforcing ribs that protrude from the case surface, effectively increasing the local thickness and moment of inertia at critical areas without increasing the overall envelope dimensions of the case. This allows weight reduction in the main case body while maintaining strength through three-dimensional structural features.
3Strength
If reinforcing ribs are added to strengthen weld line areas, then case strength is improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent applies merging by integrating the reinforcing ribs as integral features of the case itself, formed simultaneously with the case during injection molding. This eliminates the need for separate reinforcement components, fasteners, or assembly steps, thereby reducing overall device complexity while still providing the necessary strength enhancement at weld line locations.
Data Source
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AI summary
Since a second reinforcing rib (24e) protruding from a motor accommodating portion (24) to outside is provided to a portion formed with a weld line (WL) formed by the merger of molten resin (MR), the material thickness of the portion formed with the weld line (WL) can be increased. Therefore, the strength of the portion formed with the weld line (WL) is improved, and the strength of a case (21) as a whole can be improved. The case (21) sufficiently resistible to outer shocks can be achieved, and can be sufficiently used even in adverse environments such as a place near an undercarriage of a vehicle, and high reliability can be obtained. Since a small flange portion is provided on a caliper fixing portion side which supports an output shaft where large running torque is loaded, the weld line can be kept away from the caliper fixing portion, with this small flange portion taken as an inlet portion for the molten resin. Thus, with the caliper fixing portion side of the case inhibited from being distorted, it is possible to reliably inhibit unusual noise and so forth from occurring from an actuator.