Handheld Press Drive Motor Speed Feedback Control

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Solution Overview

Problem

Existing hand-guided drive devices for pressing devices lack reliability in ensuring a successful pressing process, as they rely solely on pressure relief valves and motor operation without comprehensive feedback on the achieved pressing force.

Innovation Solution

Incorporating a plausibility check at the end of the pressing process that monitors the speed of the drive motor and compares it to a target load speed range, which is adjusted based on idling speed to account for variations, providing feedback through acoustic or optical signals if the speed falls within the predetermined range, indicating a successful pressing process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If only pressure relief valve and motor operation are monitored, then the device complexity is low, but the reliability of ensuring successful pressing process is insufficient

Engineering Contradiction:
Improvereliability of pressing processVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements a feedback mechanism by monitoring the actual speed of the drive motor during the pressing process and comparing it with a predetermined target speed range. When the actual speed falls within the target range, a signal device provides feedback indicating successful completion of the pressing process. This feedback loop enhances reliability without significantly increasing device complexity.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces complex mechanical pressure measurement systems with a simpler speed-based monitoring system. By monitoring the speed of the drive motor instead of directly measuring pressing force or pressure, the system achieves reliable process verification with reduced mechanical complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If comprehensive feedback on pressing force is implemented, then the reliability is improved, but the device complexity increases

Engineering Contradiction:
Improvereliability of pressing processVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent substitutes direct mechanical measurement of pressing force with an indirect speed-based indication method. By monitoring motor speed, which correlates with the pressing process state, the system provides comprehensive feedback on pressing force without implementing complex force sensing mechanisms.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses motor speed as an intermediary parameter to indicate the state of the pressing process. Instead of directly measuring pressing force, the system monitors the intermediate variable (motor speed) that reflects the process state, thereby simplifying the measurement system while maintaining reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If speed monitoring and plausibility check are added, then the measurement precision of pressing process is improved, but the device complexity increases

Engineering Contradiction:
Improvemeasurement precision of pressing processVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex direct force measurement systems with a simpler speed monitoring system. By measuring motor speed, which is easier to measure with high precision using standard sensors, the system achieves improved measurement precision of the pressing process without adding significant complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

Enhances the reliability of the pressing process by ensuring the required pressing force is achieved and providing operators with immediate feedback on process completion, thereby improving overall operational consistency.

Implementation Method 1

the drive motor drives a hydraulic pump; the hydraulic pump acts on an actuating device in the form of a hydraulic motor

Methodology Applied
Scientific EffectHydraulic pump: Pump

Implementation Method 2

there is at least one pressure relief valve in the hydraulic system; the pressure relief valve is designed such that it opens the connection to the hydraulic reservoir when a certain cut-off pressure is reached in the hydraulic motor

Methodology Applied
Scientific EffectPressure relief valve: Valve

Implementation Method 3

the hydraulic piston is moved back into its initial position with a return spring acting on it

Methodology Applied
Scientific EffectReturn spring: Spring

Data Source

PatentEP2228178B1Handheld drive device for a press device and method for controlling a handheld drive device for a press device
Publication Date: 2012.08.22 NOVOPRESS GMBH PRESSEN UND PRESSWERKZEUGE & CO KG
  • EP2228178B1 patent drawingFigure 1
  • EP2228178B1 patent drawingFigure 2
  • EP2228178B1 patent drawingFigure 3

AI summary

The device (2) has a hydraulic motor (19) including a reset device that transports hydraulic fluid from the motor into a hydraulic reservoir (14). An actual value sensor measures a physical variable correlated with a pressing resistance and assigned to a drive motor (4). The sensor is connected to an evaluation device that stores a reference value range in which an actual value of the variable lies while reaching a cut-out pressure. A signaling device associated to the evaluation device signals whether an actual load speed lies in a preset threshold value range. An independent claim is also included for a press device including a press tool.