Chuck Jaw Position Sensing for Faster Machine Tool Loading

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Machine tools face inefficiencies in loading times and malfunctions detection due to limitations in space for proximity switches in loading devices, which hinder the detection of chuck jaw opening and closing speeds and lead to time losses and potential malfunctions.

Innovation Solution

A loading device equipped with a sensor that detects continuously changing signals for the open-end, closed-end, and movement positions of chuck jaws, allowing the movement mechanism to initiate action before the chuck jaws fully open, and utilizing dual sensors on both the loading device and spindle chucks to streamline workpiece delivery and receipt processes, enabling early detection of speed reductions and malfunctions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple proximity switches are arranged at specific intervals to detect dogs at different positions, then the detection capability of chuck jaw positions is improved, but the space requirements exceed available space in the loading device

Engineering Contradiction:
Improvedetection capability of chuck jaw positionsVSAvoidspace for sensors in loading device
Core Design Contradiction:
Measurement precisionVSArea of stationary object

Solution Approach 1:

The detection function is segmented between two sensors: one sensor on the loading device chuck detects the open-end position, while another sensor on the spindle chuck detects the closed-end position. This segmentation allows position detection without requiring multiple sensors in the limited loading device space.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The detection system transitions from a single-location detection approach to a distributed detection approach across different spatial locations (loading device chuck and spindle chuck), effectively using spatial dimensionality to resolve the space constraint problem.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If the movement mechanism waits for the chuck jaws to fully open before moving the chuck, then the workpiece delivery is ensured to be safe, but the loading time increases and throughput decreases

Engineering Contradiction:
Improveworkpiece delivery safetyVSAvoidloading time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The movement mechanism initiates movement of the chuck before the chuck jaws complete their opening action. By detecting the open-end position during the opening process rather than waiting for full opening, the system performs the movement action in advance, reducing loading time while maintaining delivery safety through continuous position monitoring.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The sensor continuously detects the open-end position of the chuck jaws and provides feedback to the movement mechanism. This feedback enables the movement mechanism to determine the appropriate timing for chuck movement based on real-time jaw position information, optimizing both safety and efficiency.

Inventive Principle:
Principle #23Feedback

3Device complexity

If only the open-end and closed-end positions of chuck jaws are detected, then the basic chucking function is achieved, but malfunctions such as reduced opening and closing speed cannot be detected

Engineering Contradiction:
Improvedetection system simplicityVSAvoidmalfunction detection capability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The sensor detects the open-end position during the opening process before the chuck jaws reach their fully open state. This preliminary detection provides timing information that enables calculation of opening speed, allowing malfunction detection while maintaining a relatively simple detection system structure.

Inventive Principle:
Principle #10Preliminary action

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 significantly reduces loading time, enhances efficiency, and allows for timely detection of chuck jaw issues, improving overall productivity and enabling proactive maintenance.

Implementation Method 1

a sensor (25a) being provided in the main chuck jaws (21a) to detect a continuously changing signal depending on an open-end position of the main chuck jaws (21a), a closed-end position of the main chuck jaws (21a), and movement position between the open-end position and the closed-end position

Methodology Applied
Scientific EffectPosition detection via sensor signal:

Data Source

PatentEP3441204B1Loading device and method tool using the same
Publication Date: 2023.08.02 NAKAMURATOME SEIMITSU IND
  • EP3441204B1 patent drawingFigure 1
  • EP3441204B1 patent drawingFigure 2A~2C
  • EP3441204B1 patent drawingFigure 3~4

AI summary

A loading device (20) has a chuck (21, 22) that chucks a workpiece W on chuck jaws (21a, 22a) that are opened and closed, and a movement mechanism (60) that moves the chuck and delivers the workpiece W to and from a spindle (11, 31) of a machine tool (1A, 1B). The loading device (20) has a sensor (25a, 25b) that detects a continuously changing signal depending on an open-end position of the chuck jaws, a closed-end position of the chuck jaws, and a movement position between the open-end position and the closed-end position. The movement mechanism (60) is capable of starting to move the chuck (21, 22) when the chuck jaws (21a, 22a) are in the movement position, based on an output from the sensor (25a, 25b).