Press-Fit Nut Structure for Lower Load Plate Fixing
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Solution Overview
Problem
Conventional nuts require high loads for press-fitting, leading to unnecessary deformation of the mating member, necessitating a reduction in the required load for effective fixation.
Innovation Solution
A nut design featuring a base with a female screw, a cylindrical protrusion part, and foot parts with expanding widths and arc-shaped ends, allowing for deformation of the mating member without excessive load, using a pilot hole that accommodates the protrusion part and deforms the plate material with the foot parts for secure fixation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional press-fitting method is used to fix the nut to the mating member, then the nut can be firmly embedded and prevented from rotating or falling off, but the required load is large causing unnecessary deformation in the mating member
Solution Approach 1:
The nut is divided into three functional segments: a base part with female screw, a cylindrical protrusion part for insertion, and multiple foot parts for deformation. This segmentation allows each part to perform its specific function - the protrusion part enters the pilot hole while the foot parts deform the mating member to create fixation, thereby reducing the overall load required compared to conventional uniform press-fitting methods
Solution Approach 2:
The foot parts are designed with specific local geometries including arc-shaped outer sides and expanding widths toward the protrusion part. These local quality features concentrate the deformation action at specific contact points with the mating member, allowing effective fixation with reduced overall load and minimizing unnecessary deformation in non-critical areas
2Strength
If high load is applied for press-fitting the nut, then secure fixation is achieved, but unnecessary deformation occurs in the mating member
Solution Approach 1:
The nut design incorporates a pilot hole in the mating member that is larger than the largest outer periphery of the protrusion part. This preliminary preparation allows the protrusion part to be inserted first without requiring high load, and subsequent deformation by the foot parts achieves fixation with controlled, minimal deformation
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 reduces the load required for press-fitting the nut into a plate material, minimizing deformation and enhancing the caulking strength while maintaining secure attachment.
Implementation Method 1
deformed by the foot parts to fix the nut to the mating member
Data Source
AI summary
To reduce the load required to press-fit a nut into a plate material, the nut includes a base part 2 provided with a female screw 18, a cylindrical protrusion part 3 protruding from one surface of the base part and a plurality of foot parts 4 protruding from an outer peripheral surface side of the protrusion part. An end of the respective foot parts closer to the protrusion part is formed so that a width gradually expands from a tip end side toward a protrusion part side, and that both outer sides of the end are arc-shaped in plan view.