Automatic Lathe Friction Joining With Misalignment Detection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing techniques for detecting misalignment during friction joints in machine tools can only determine if misalignment occurs, but not the degree of misalignment.

Innovation Solution

A machine tool with a control system that includes a misalignment amount detecting means to determine the degree of misalignment between workpieces during friction joint, and a second spindle moving means to adjust the position of the second spindle based on the detected misalignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If misalignment detection is implemented during friction joint, then misalignment can be detected, but the degree of misalignment cannot be determined

Engineering Contradiction:

Improvemisalignment detection capabilityVSAvoidmisalignment degree information

Core Design Contradiction:

Measurement precisionVSLoss of information

Solution Approach 1:

The patent replaces mechanical measurement methods with optical measurement technology. A laser displacement sensor is used to non-contactively measure the position of the workpiece during friction joint, enabling precise quantification of misalignment degree without mechanical interference. This optical substitution allows both detection and measurement of misalignment in real-time.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If friction joint is performed without misalignment correction, then manufacturing efficiency is maintained, but product quality and material utilization deteriorate

Engineering Contradiction:

Improvemanufacturing efficiencyVSAvoidjoint alignment accuracy

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent implements preliminary misalignment correction by detecting misalignment degree during the friction joint process and automatically adjusting the workpiece position before the joint is completed. This preliminary correction action prevents final misalignment issues while maintaining continuous production flow, thus preserving both productivity and manufacturing precision.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system establishes a feedback loop where the laser displacement sensor continuously monitors misalignment degree, and the control unit automatically adjusts the workpiece position based on this feedback. This closed-loop control ensures high alignment accuracy without requiring manual intervention, maintaining manufacturing efficiency while improving product quality.

Inventive Principle:

Principle #23Feedback

3Manufacturing precision

If automatic misalignment correction is implemented during friction joint, then manufacturing precision is improved, but device complexity increases

Engineering Contradiction:

Improveworkpiece alignment accuracyVSAvoidcontrol system complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent introduces a laser displacement sensor as an intermediary measurement device that non-contactively measures workpiece position. This intermediary enables precise misalignment detection without adding complex mechanical adjustment mechanisms, thereby improving manufacturing precision while minimizing device complexity through non-contact measurement.

Inventive Principle:

Principle #24Intermediary (Mediator)

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

Enables precise determination of misalignment during friction joints, allowing for corrective action before the joint is completed, which reduces manufacturing costs and stabilizes product quality.

Implementation Method 1

the misalignment amount detecting means obtains the misalignment amount of the second workpiece with respect to the first workpiece on the basis of a load applied to a motor for moving the second spindle in the direction intersecting the rotation axis of the second spindle

Methodology Applied

Scientific EffectLoad measurement:

Implementation Method 2

the misalignment amount detecting means obtains the misalignment amount of the second workpiece with respect to the first workpiece on the basis of an output value of an optical sensor for measuring distance to the second workpiece

Methodology Applied

Scientific EffectOptical distance measurement:

Implementation Method 3

pushing a rear end portion of the second workpiece against a front end portion of the first workpiece to frictionally join the first and second workpieces

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS12269111B2Machine tool and control method of machine tool

Publication Date: 2025.04.08 CITIZEN WATCH CO LTD

AI summary

A machine tool and a control method for the machine tool, which determine the degree of misalignment during friction joint, are provided. The machine tool (an automatic lathe 1) includes: a first spindle 10 rotatably holding a first workpiece (a workpiece W1); a second spindle 20 arranged to face the first spindle and rotatably holding a second workpiece (a remaining workpiece W2); and a controller 40a, while rotating at least one of the first workpiece or the second workpiece, relatively moving the first spindle and the second spindle so as to get closer to each other and pushing a rear end portion of the second workpiece against a front end portion of the first workpiece to frictionally join the first and second workpieces. The controller has a misalignment amount detector detecting a misalignment amount s of the second workpiece with respect to the first workpiece during the friction joint.