Rotatable Clamp Mechanism for Coil Spring Negative Pitch Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional coil spring manufacturing devices are limited in forming a negative pitch portion with sufficient length and angle, restricting the ability to achieve a desired negative pitch in coil springs used for suspension mechanisms.

Innovation Solution

The device includes a clamp mechanism with slide and rotation actuators to move and orient clamp members, allowing for increased length and angle of the negative pitch portion by using different chuck members and guide mechanisms to control the wire's pitch and orientation during coiling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the distal end portion of the wire is sandwiched between clamp members to form a bent portion for the end turn portion of a negative pitch, then the coil spring can be manufactured with a negative pitch portion, but the length and angle of the bent portion are restricted by the shape or arrangement of the clamp members, resulting in a small negative pitch portion length and negative pitch angle

Engineering Contradiction:
Improvenegative pitch angleVSAvoidclamp mechanism arrangement
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The clamp mechanism is made rotatable about the mandrel axis, allowing the orientation of the clamp members to be dynamically adjusted. This enables the formation of bent portions with various lengths and angles by rotating the clamp mechanism to different angular positions, thereby achieving desired negative pitch parameters without being restricted by fixed clamp member arrangements

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The solution introduces rotational movement around the mandrel axis as an additional degree of freedom. By rotating the clamp mechanism about the mandrel axis, the system can achieve different negative pitch angles and lengths by changing the angular position, effectively adding a rotational dimension to the wire bending process

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Length of moving object

If the clamp members are arranged in a fixed configuration to sandwich the wire, then the device structure is simple, but the length of the negative pitch portion and the negative pitch angle are limited and cannot achieve desired values

Engineering Contradiction:
Improvenegative pitch portion lengthVSAvoidclamp mechanism adjustment
Core Design Contradiction:
Length of moving objectVSEase of operation

Solution Approach 1:

The clamp mechanism is equipped with rotational capability about the mandrel axis, transforming it from a static structure to a dynamic one. This allows the operator to adjust the clamp mechanism's angular position to achieve the desired negative pitch portion length and angle, making the device adaptable to various coil spring specifications

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If conventional clamp members are used to form the end turn portion, then the device structure remains simple, but the force line position optimization is limited due to restricted negative pitch parameters

Engineering Contradiction:
Improveforce line position optimizationVSAvoidnegative pitch angle
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

By making the clamp mechanism rotatable, the system can dynamically adjust the wire bending parameters to optimize the force line position for different coil spring applications. The rotational capability allows precise control over the negative pitch angle, enabling better force line position optimization

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The rotational adjustment of the clamp mechanism enables continuous variation of the negative pitch angle and portion length parameters. This parameter flexibility allows optimization of the force line position according to specific suspension mechanism requirements, enhancing the adaptability of the coil spring manufacturing device

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3263243B1Device for manufacturing coil spring and method for manufacturing coil spring
Publication Date: 2020.04.29 NHK SPRING CO LTD
  • EP3263243B1 patent drawingFigure 1
  • EP3263243B1 patent drawingFigure 2
  • EP3263243B1 patent drawingFigure 3

AI summary

A coil spring manufacturing device (10) includes a mandrel (11) around which a wire (W) is wound, a feed mechanism (12) which feeds the wire (W) toward the mandrel (11), guide members (15, 16) which guide the wire (W), a chuck (13) which fixes a distal end (W1) of the wire (W), and a clamp mechanism (71). The clamp mechanism (71) sandwiches the wire (W) from both sides before the distal end (W1) of the wire (W) reaches the mandrel (11). Further, the clamp mechanism (71) can be rotated about a fulcrum (80) by rotation means, and can also be slid in a direction along an axis (X1) of the mandrel (11) by slide means. In a state in which the wire (W) is sandwiched by the clamp mechanism (71), the clamp mechanism (71) is rotated, and if necessary, is slid. Thereby, a bent portion (W2) for a negative pitch portion of a coil spring is formed at a part of the wire (W).