Movement Detecting Device Single-Step Caulking Assembly

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Solution Overview

Problem

Existing movement detecting devices in pneumatic actuators require multiple assembly steps, leading to potential errors in relative positional accuracy between the plunger and magnet carrier, resulting in variations in detection accuracy.

Innovation Solution

A movement detecting device with a cylindrical magnet and a moving holder featuring a space that allows direct fixation of the drive shaft, enabling a single-step assembly and maintaining accurate relative positions through caulking, allowing for integrated molding of synthetic resin and metal components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the magnet carrier is fixed after the shaft is connected to the plunger, then the assembly can be completed, but the assembly process requires multiple steps and time-consuming operations

Engineering Contradiction:

Improveassembly speedVSAvoidassembly process complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent combines the magnet carrier and plunger into a single integrated component. The magnet carrier is formed as an integral part of the plunger body, eliminating the need for separate assembly steps to fix the magnet carrier to the plunger. This merging of components directly reduces assembly time and process complexity while maintaining the functional separation needed for the linear position sensor operation.

Inventive Principle:

Principle #5Merging (Combining)

2Manufacturing precision

If the magnet carrier is assembled after the shaft connection, then the assembly sequence can be followed, but the relative positional accuracy between plunger and magnet carrier varies

Engineering Contradiction:

Improverelative positional accuracyVSAvoiddetection accuracy consistency

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

By integrating the magnet carrier as an integral part of the plunger, the patent eliminates relative positional variations between these two components. The magnet carrier and plunger move together as a single unit, ensuring consistent detection accuracy across all actuators. This integration prevents assembly errors and maintains reliable relative positioning throughout the linear position sensor's operation.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The magnet carrier is formed in advance as an integral part of the plunger during the plunger manufacturing process, rather than being assembled later. This preliminary integration ensures that the relative positional relationship is established with high precision during manufacturing, eliminating subsequent assembly variations and ensuring consistent detection accuracy.

Inventive Principle:

Principle #10Preliminary action

3Ease of manufacture

If the plunger and magnet carrier are not integrated, then separate manufacturing is possible, but insert molding or outsert molding cannot be used

Engineering Contradiction:

Improvemolding process applicabilityVSAvoidrelative positional accuracy

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent merges the magnet carrier and plunger into a single component that can be manufactured using insert molding or outsert molding processes. The magnet carrier is integrated into the plunger body, allowing these advanced molding techniques to be applied. This integration enables precise positioning of the magnet carrier relative to the plunger while taking advantage of efficient molding manufacturing methods.

Inventive Principle:

Principle #5Merging (Combining)

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 solution simplifies the assembly process and ensures precise detection of the magnet's movement with reduced variations, enhancing the accuracy and reliability of the linear position sensor.

Implementation Method 1

a magnet that is fixed to the moving holder, the magnet having a cylindrical shape; and magnetism detectors that are fixed to the housing and detect a magnetic field generated from the magnet

Methodology Applied

Scientific EffectMagnetic field: Magnetic Field

Data Source

PatentEP2843371B1Movement detecting device, actuator, and method of assembling actuator

Publication Date: 2018.10.10 ALPS ALPINE CO LTD

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AI summary

A metal bush (32) is mounted on a moving holder (10) made of a synthetic resin, and a drive shaft (20) is inserted into the metal bush (32) while a diaphragm (5) is interposed between the moving holder (10) and a metal support member (33). A space (13) is formed in a holding portion (12) holding a magnet (14) and a tip portion (20a) of the drive shaft (20) is pressed in the space (13), so that a caulked portion (23) is formed. Since the space (13) is formed, the moving holder (10), the diaphragm (5), and the drive shaft (20) can be integrally fixed by one caulking step.