Sub-Spindle Cross Drilling-Milling Unit to Prevent Mandrel Tilting

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Solution Overview

Problem

Conventional cross drilling-milling units for sub spindles suffer from mandrel tilting during adjustment, leading to inaccurate processing and transmission issues.

Innovation Solution

A cross drilling-milling unit with a body having multiple decks and a slit configuration that provides two-position constraints to prevent mandrel tilting, using adjusting screws to clamp the mandrel assembly while maintaining support from adjacent decks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the two bulks are loosened to allow mandrel assembly adjustment, then the mandrel assembly can be repositioned, but the mandrel assembly tilts and loses positional accuracy

Engineering Contradiction:
Improvemandrel assembly repositioningVSAvoidmandrel assembly positional accuracy
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The mounting portion is segmented into three decks (first, second, and third decks) arranged along the first direction. The second deck contains the slit with two bulks for clamping, while the first and third decks provide additional constraint points. This segmentation allows the mandrel assembly to be repositioned by loosening only the adjusting screw on the second deck, while the first and third decks maintain positional constraints to prevent tilting.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first and third decks act as intermediary constraint structures between the adjustable second deck and the mandrel assembly. When the adjusting screw is loosened, these intermediary decks provide continuous support and constraint, preventing the mandrel assembly from tilting or swinging during the adjustment process, thereby maintaining positional accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the adjusting screw is loosened to move the mandrel assembly, then position adjustment is enabled, but support and limitation are lost causing mandrel tilting

Engineering Contradiction:
Improvemandrel assembly position adjustmentVSAvoidmandrel assembly stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The mounting portion is divided into three functional decks: the first and third decks provide stable constraint points, while the second deck contains the adjustable clamping mechanism. This segmentation enables position adjustment through the adjusting screw while the first and third decks maintain structural stability and prevent mandrel tilting.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first and third decks are pre-configured to provide constraint and support before the adjusting screw is loosened. This preliminary constraint structure ensures that when adjustment is needed, the mandrel assembly remains stable and does not tilt or swing, even though the adjusting screw is in a loosened state.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If the two bulks clamp the mandrel assembly tightly, then transmission accuracy is improved, but adjustment becomes difficult

Engineering Contradiction:
Improvetransmission accuracyVSAvoidmandrel assembly adjustability
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The mounting portion is segmented into three decks with the adjusting mechanism localized to the second deck only. This allows the adjusting screw to be operated independently to loosen or tighten the clamping force on the mandrel assembly, enabling easy adjustment when needed while maintaining tight clamping for accurate transmission during operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The clamping force on the mandrel assembly is made dynamic through the adjusting screw mechanism. The two bulks can transition between a loosened state (for easy adjustment) and a tightened state (for accurate transmission). This dynamic adjustment capability resolves the contradiction between ease of operation and transmission precision.

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

Prevents mandrel tilting and swinging, ensuring precise processing and maintaining effective transmission by constraining the mandrel assembly during adjustments.

Implementation Method 1

The two bulks are configured to clamp the mandrel assembly when an adjusting screw forces the two bulks to approach each other

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 2

The transmitting assembly is mounted inside the body, and is configured to be driven by a spindle of the machine tool and rotate the mandrel assembly

Methodology Applied
Scientific EffectMechanical Transmission: Gear

Data Source

PatentEP4516449B1Cross drilling-milling unit for sub spindle
Publication Date: 2025.10.29 VERNAL MFG & ENG CO LTD
  • EP4516449B1 patent drawingFigure 1
  • EP4516449B1 patent drawingFigure 2
  • EP4516449B1 patent drawingFigure 3

AI summary

The present invention provides a cross drilling-milling unit for a sub spindle having a body (10) and a mandrel assembly (40). The body (40) has a first direction (D1), a second direction (D2) being perpendicular to the first direction (D1), and a mounting portion (11) having a first deck (111), a second deck (112), and a third deck (113) arranged along the first direction (D1) in order and spaced apart from one another. The mandrel assembly (40) is disposed through the three decks along the first direction (D1) and is mounted on the mounting portion (11). The second deck (112) has a slit (110) disposed along the second direction (D2) and separating the second deck (112) into two bulks (114), and the two bulks (114) are configured to clamp the mandrel assembly (40) when forced to move toward each other.