Injection Mold Blade Fixed Block for Automatic Gate Cutting

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Solution Overview

Problem

Existing cold cutting methods for injection molds, such as air cutting, sawing-cutting, chopping-cutting, and conventional submarine gate methods, face issues like cutter damage, poor notch quality, increased design complexity, and limitations in handling large and thin-walled products due to defects like breaking creases and uneven surfaces.

Innovation Solution

An injection mold with a blade fixed block and ejectors that automatically cut gates without additional drive mechanisms, utilizing cut holes and ejector holes to limit and guide the blade fixed block, allowing for controlled cutting and ejection of condensed material, thereby achieving an automatic shearing process that minimizes cutter damage and improves notch quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If air cutting method is used to cut gates, then cutting can be performed, but cutters are easily damaged and notches have poor flatness

Engineering Contradiction:

Improvegate cutting capabilityVSAvoidcutter durability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

Instead of using air cylinders to drive cutters upward from the bottom (conventional approach), the patent inverts the mechanism by using ejectors to push condensed material laterally against stationary blades. This reverses the traditional cutting mechanism, eliminating the need for complex air cylinder drive systems and improving cutter reliability while maintaining cutting functionality.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent replaces the pneumatic mechanical system (air cylinders driving cutters) with a simpler mechanical system where ejectors directly push condensed material against blades. This substitution eliminates the need for air cylinder control systems and reduces the complexity of the cutting mechanism while improving reliability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If air cylinder drives cutters to cut gates, then cutting action is achieved, but additional drive mechanisms increase device complexity

Engineering Contradiction:

Improveautomatic gate cuttingVSAvoidcontrol system requirements

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent employs a self-service mechanism where the ejectors, already present for product ejection, automatically perform the gate cutting function by pushing condensed material against blades. This eliminates the need for separate air cylinder drive mechanisms and control systems, reducing device complexity while maintaining automatic cutting capability.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The ejectors serve dual functions: product ejection and gate cutting. By making the ejectors multi-functional, the patent eliminates the need for dedicated cutting drive mechanisms, thereby reducing overall device complexity while achieving automatic gate cutting.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If cutters are pulled out after mold opens 20-30mm, then cutter damage is prevented, but product cannot be ejected and additional ejectors are required

Engineering Contradiction:

Improvecutter protectionVSAvoidejector system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent performs gate cutting during the ejection phase itself, rather than waiting for the mold to open and then attempting to pull out cutters. By initiating the cutting action preliminarily during ejection, the system avoids the need for separate cutter retrieval operations and additional ejectors, while still protecting cutters from damage.

Inventive Principle:

Principle #10Preliminary action

4Productivity

If sawing-cutting method is used, then cutting can be performed, but strong extrusion and friction damage gate portions and reduce mold service life

Engineering Contradiction:

Improvegate cutting capabilityVSAvoidfriction and extrusion damage

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the sawing-cutting method (which involves strong extrusion and friction) with a lateral pushing mechanism where ejectors push condensed material against blades. This substitution reduces friction and extrusion forces, thereby minimizing damage to gate portions and extending mold service life while maintaining cutting capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS11911942B2Injection mold capable of planning and cutting gates in inside thereof and planning and cutting method

Publication Date: 2024.02.27 ZHUJI BIHAN FINE MOLDING

AI summary

An injection mold capable of planing and cutting gates in an inside thereof and a planing and cutting method are provided. The injection mold includes a blade fixed block arranged between a moving mold and a fixed mold. Blades arranged on the blade fixed block and configured for cutting off gate condensed-material. The mold includes ejectors for ejecting out the gate condensed material and the blade fixed block. Runners formed between the blade fixed block and the fixed mold. Cut holes for communicating runners and gates are formed in blades. Ejector holes for penetrating the ejectors are formed in portions of the blade fixed block which correspond to bottoms of runners. The blade fixed block moves relative to the moving mold in a mold opening direction. The moving mold is provided with a limiting mechanism for limiting the blade fixed block after injection molding parts are separated from a cavity.