Combination scale

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Solution Overview

Problem

Conventional combination scales face thermal management issues due to elevated internal temperatures from heat generated by driving units and hot articles, leading to unstable weight values and the need for costly ventilation solutions like fans.

Innovation Solution

A combination scale design utilizing an ejector and air purge device for efficient ventilation without fans, using compressed air to suction and release hot air, maintaining internal pressure higher than atmospheric pressure to prevent dust and water ingress, and utilizing existing compressors for cooling, thereby eliminating the need for fan motors and reducing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If electrically-driven fans are used for ventilation to cool the cabinet interior, then the cabinet temperature is reduced, but fan motors generate additional heat and require costly waterproof wiring systems

Engineering Contradiction:
Improvecabinet interior temperatureVSAvoidheat from fan motors and waterproofing requirements
Core Design Contradiction:
TemperatureVSObject-generated harmful factors

Solution Approach 1:

The patent removes the fan motor from the cabinet interior, extracting the heat-generating component that caused the technical contradiction. Instead of using electrically-driven fans inside the cabinet, the invention uses an ejector positioned outside the cabinet that utilizes compressed air to create airflow for cooling the interior without introducing additional heat sources or waterproofing requirements

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies pneumatic principles by using an ejector that operates on compressed air to generate cooling airflow. The ejector converts compressed air into a high-velocity jet that induces ambient air flow through the cabinet, providing ventilation and cooling without requiring electric motors or complex waterproof wiring systems

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Temperature

If Peltier devices are used for direct cooling of the cabinet, then the location and vicinity are efficiently cooled, but additional fans are still needed for overall cabinet ventilation, increasing cost

Engineering Contradiction:
Improvelocal cooling efficiencyVSAvoidneed for additional fans and ventilation system
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent combines the cooling function and ventilation function into a single integrated system. The ejector simultaneously provides the cooling airflow and the overall cabinet ventilation, eliminating the need for separate fans and simplifying the system architecture while reducing costs

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If the cabinet is sealed to block foreign matter, then protection is improved, but heat accumulates inside affecting weight sensor stability

Engineering Contradiction:
Improveprotection against foreign matterVSAvoidinternal temperature stability
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The patent introduces dynamic airflow control into the previously static sealed cabinet system. The ejector creates controlled air circulation that dynamically adjusts to cooling requirements, allowing the cabinet to maintain its sealed protective structure while actively managing internal temperature through regulated airflow paths

Inventive Principle:
Principle #15Dynamics

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 effectively cools the internal cabinet, stabilizing weight measurements and improving accuracy by removing hot air without the heat generation and cost associated with fan motors, while maintaining a waterproof structure.

Implementation Method 1

an ejector to be supplied with compressed air to ventilate the cabinet

Methodology Applied
Scientific EffectVacuum effect: Pressure Gradient

Implementation Method 2

the ejector allows waterproof electric wirings to be dispensed with. Further advantageously the ejector is a space-saving device relatively small in size

Methodology Applied
Scientific EffectCompressed air expansion: Adiabatic Cooling

Data Source

PatentEP3029436B1Combination scale
Publication Date: 2019.05.15 YAMATO SCALE CO LTD
  • EP3029436B1 patent drawingFigure 1
  • EP3029436B1 patent drawingFigure 2
  • EP3029436B1 patent drawingFigure 3

AI summary

This invention relates to a combination scale including an ejector to be supplied with compressed air to ventilate a central cabinet of the combination scale, wherein an interior of the central cabinet and a suction port of the ejector are connected to and communicating with each other.