Injection Molding Machine Spigot Fitting for Precise Assembly

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing injection molding machines suffer from inadequate centering and positioning accuracy between components, leading to unbalanced loads and reduced assembly accuracy.

Innovation Solution

The implementation of a spigot-fitting mechanism between the base and assembled members in the injection molding machine, ensuring precise alignment and centering of components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional assembly methods are used to connect the motor and motion conversion mechanism to the base, then the assembly process is simple, but assembly accuracy and centering precision are insufficient

Engineering Contradiction:
Improveassembly accuracyVSAvoidassembly structure complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

A spigot fitting structure is introduced as an intermediary component between the base and assembled members (motor, motion conversion mechanism). The spigot fitting includes a spigot portion protruding from one component and a corresponding recess in the other component, creating a precise mechanical interface that ensures accurate centering and positioning without complex assembly procedures

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The spigot fitting structure is pre-designed and pre-positioned on the base and assembled members before final assembly. This preliminary arrangement of fitting portions ensures that when components are brought together, they automatically achieve precise centering and alignment in the front-rear direction, eliminating the need for post-assembly adjustment

Inventive Principle:
Principle #10Preliminary action

2Reliability

If centering between the electric motor and rear plate is not performed, then the assembly process is faster, but unbalanced load is applied to the spline

Engineering Contradiction:
Improveload distribution balanceVSAvoidassembly time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The spigot fitting acts as a mediator that automatically transfers and distributes loads evenly between the motor and rear plate through its precise geometric interface. The fitting structure ensures balanced load distribution on the spline connection without requiring time-consuming manual centering operations, as the spigot-recess geometry inherently aligns the components

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The spigot fitting structure is pre-configured with precise dimensions and tolerances that ensure proper centering and load distribution before assembly. This preliminary design ensures that when the motor and rear plate are assembled, the load is automatically balanced across the spline interface, eliminating the need for post-assembly load balancing adjustments

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3683034B1Injection molding machine
Publication Date: 2023.10.18 SUMITOMO HEAVY IND LTD
  • EP3683034B1 patent drawingFigure 1
  • EP3683034B1 patent drawingFigure 2
  • EP3683034B1 patent drawingFigure 3

AI summary

The present invention provides an injection molding machine capable of improving assembly accuracy between members configuring the injection molding machine. The injection molding machine includes a motor, a motion conversion mechanism which includes a screw shaft which is rotated by the motor and a screw nut which is screwed to the screw shaft and is moved forward or rearward by a rotation of the screw shaft, and a base to which the motor and the motion conversion mechanism are assembled, and the base and a member assembled to the base are spigot-fitted to each other.