Multipole Rod Electrode Assembly to Preserve Spectrum Resolution

Solution Overview

Problem

The assembly of multipole electrodes in mass spectrometers can cause deformation of main and pre-rods due to torque from screws, leading to decreased sensitivity and resolution of the detected spectrum.

Innovation Solution

The pre-rods and main rods are connected via an insulation member, with the pre-rods having a larger diameter than the main rods, and aligned using an assembling guide jig to minimize tilting and deformation during assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If screws are used to fix the coupling portion of pre-rods and main rods, then the rods can be securely connected, but deformation occurs due to screw torque

Engineering Contradiction:

Improveconnection strengthVSAvoidrod straightness

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The multipole rod electrode is divided into multiple segments (pre-rod and main rod portions) that are connected via coupling portions. This segmentation allows each rod to be independently positioned and aligned before assembly, reducing the risk of deformation during connection while maintaining secure coupling through the screw mechanism.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The rods are preliminarily aligned and positioned in the assembling guide jig before the actual screw fixation. This preliminary action ensures that the rods are correctly oriented and straight before the coupling is secured, preventing deformation that would occur if alignment were attempted after screw tightening.

Inventive Principle:

Principle #10Preliminary action

2Stability of the object's composition

If the rods are tightly fixed to ensure stability, then the structure becomes stable, but the sensitivity and resolution of the spectrum decrease due to deformation

Engineering Contradiction:

Improvestructural stabilityVSAvoidspectrum resolution

Core Design Contradiction:

Stability of the object's compositionVSMeasurement precision

Solution Approach 1:

The rods are preliminarily aligned and positioned in the assembling guide jig before the actual screw fixation. This preliminary action ensures that the rods are correctly oriented and straight before the coupling is secured, preventing deformation that would occur if alignment were attempted after screw tightening.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The coupling portion acts as an intermediary element between the pre-rod and main rod. It provides a dedicated interface for connection that includes positioning features (such as grooves and protrusions) to maintain alignment and reduce stress concentration, thereby preserving rod straightness while achieving stable fixation.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Productivity

If the rods are assembled without guidance to simplify the process, then the assembly is faster, but tilting and misalignment occur reducing manufacturing precision

Engineering Contradiction:

Improveassembly speedVSAvoidrod alignment

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The assembling guide jig incorporates self-aligning features such as grooves and protrusions that automatically guide the pre-rods and main rods into correct alignment during assembly. This self-service mechanism eliminates the need for complex external alignment tools or manual adjustment, maintaining high precision while enabling efficient assembly.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The coupling portion acts as an intermediary element between the pre-rod and main rod. It provides a dedicated interface for connection that includes positioning features (such as grooves and protrusions) to maintain alignment and reduce stress concentration, thereby preserving rod straightness while achieving stable fixation.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentEP4661052A1Mass spectroscope and method for assemblying pre-rods and main rods of mass spectroscope

Publication Date: 2025.12.10 HITACHI HIGH TECH CORP

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AI summary

Provided is a mass spectroscope capable of suppressing decreases in spectral sensitivity and resolution due to deformation during assembly of a multipole electrode. A mass spectroscope 28 comprises a multipole rod electrode 1 having a plurality of rod pairs (2A-1, 2A-2 ...). The rod pairs (2A-1, 2A-2 ...) are composed of pre-rods 2A-1 to 2D-1 and main rods 2A-2 to 2D-2 that are connected in the direction of an ion optical axis via an insulation member 6. In the multipole rod electrode 1, the pre-rods 2A-1 to 2D-1 constitute pre-rod electrode portions, and the main rods 2A-2 to 2D-2 constitute main rod electrode portions. The diameter of an inscribed circle 3 on which the pre-rod electrode portions 2A-1 to 2D-1 surround the ion optical axis is equal to the diameter of the inscribed circle 3 on which the main rod electrode portions surround the ion optical axis, and the diameter of all of the pre-rods 2A-1 to 2D-1 of the multipole rod electrode 1 is greater than the diameter of the main rods 2A-2 to 2D-2 connected to the pre-rods 2A-1 to 2D-1.