Air Compressor Control Circuit Adapts Motor Speed to Pressure Change Rate

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Solution Overview

Problem

Existing air compressors fail to optimally respond to varying user operation conditions, leading to either excessive or insufficient compressed air supply, and they do not adequately address noise reduction, which limits their continuous use time and usability.

Innovation Solution

An air compressor with a control circuit that stores operation history data to adjust motor rotational speed and restart pressure based on usage patterns, switching between multiple modes to optimize air supply timing and reduce noise by varying the motor's rotational speed according to the pressure change rate and consumption patterns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the motor is restarted based on a fixed reference pressure value, then the control logic is simple, but the air compressor cannot adapt to varying user operation conditions resulting in excessive or insufficient compressed air supply

Engineering Contradiction:
Improveadaptability to user operation conditionsVSAvoidcontrol logic complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The reference restart pressure is changed from a fixed value to a dynamic value that varies according to the pressure change rate. The control circuit determines the reference restart pressure based on the detected pressure change rate, allowing the system to adapt to different usage conditions (rapid consumption vs. slow consumption) without requiring complex multi-mode switching logic

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control circuit continuously monitors the pressure change rate in the tank and uses this feedback information to dynamically adjust the reference restart pressure. This feedback mechanism enables the system to automatically adapt to varying air consumption patterns while maintaining relatively simple control logic

Inventive Principle:
Principle #23Feedback

2Productivity

If the motor operates at high rotational speed to quickly replenish compressed air, then the response to air consumption is fast, but the noise level increases and continuous use time is reduced

Engineering Contradiction:
Improveair replenishment speedVSAvoidnoise level
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The motor rotational speed is changed from a fixed high speed to a dynamic speed that adapts to the air consumption rate. The control circuit sets the motor to rotate at a first rotational speed when the pressure change rate indicates rapid consumption, and at a second rotational speed when consumption is slower, thereby reducing noise while maintaining adequate air replenishment

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The motor rotational speed parameter is dynamically changed based on the detected pressure change rate. By adjusting this parameter according to actual usage conditions, the system achieves optimal balance between air replenishment speed and noise reduction without requiring complex mechanical modifications

Inventive Principle:
Principle #35Parameter changes

3Duration of action of stationary object

If the motor is restarted at a fixed reference pressure regardless of usage pattern, then the control system is simple, but the continuous use time is limited due to frequent restarts

Engineering Contradiction:
Improvecontinuous use timeVSAvoidcontrol system complexity
Core Design Contradiction:
Duration of action of stationary objectVSDevice complexity

Solution Approach 1:

The reference restart pressure is dynamically adjusted based on the pressure change rate rather than using a fixed value. This allows the system to extend continuous use time by setting higher reference pressures during rapid consumption and lower reference pressures during slow consumption, reducing unnecessary restarts while keeping control logic relatively simple

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 allows for appropriate rotational speed settings based on user conditions, increasing continuous use time while reducing noise and improving responsiveness to user expectations by optimizing air supply timing and reducing motor noise.

Implementation Method 1

a pressure sensor that detects the pressure of air in the tank (50)

Methodology Applied
Scientific EffectPressure sensing:

Data Source

PatentEP2758668B1Air compressor
Publication Date: 2020.04.15 KOKI HLDG CO LTD
  • EP2758668B1 patent drawingFigure 1A
  • EP2758668B1 patent drawingFigure 1B
  • EP2758668B1 patent drawingFigure 1C

AI summary

An air compressor comprising: a tank (50), a compression mechanism (30), a motor (5) and a control circuit (7). The control circuit (7) includes a CPU (70) and a storing unit (74) which stores a control program, the compressor operation history and a plurality of operation modes. Each of the operation modes is defined by two setting values: a reference restart pressure value and a motor rotational speed value, at least one of these values being different from among the plurality of modes. The control circuit (7) executes one of the plurality of modes as a target mode in which the control unit controls the motor to restart by comparing the pressure in the tank with the reference restart pressure and rotates the motor at the rotational speed of the target mode. The control circuit changes the target mode from the one of the plurality of modes to another one of the plurality of modes based on the compressor operation history.