Tunnel Excavator With Collapsible Plates for Reverse Travel

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Solution Overview

Problem

Conventional tunnel excavation devices are unable to travel in reverse, which is necessary for pit mining and curved line construction due to the reduction in tunnel inner diameter caused by concrete spraying and timbering support, leading to blockage and inability to navigate curved paths.

Innovation Solution

A tunnel excavation device with a front body section featuring a cutter head, collapsing peripheral plates, and a rear body section with gripper sections, allowing the device to adjust its diameter and navigate in reverse by collapsing inward components such as buckets and peripheral plates, and utilizing hydraulic systems for maneuvering in curved tunnels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the tunnel inner diameter is reduced by concrete spraying and timbering support, then the tunnel structure is strengthened and stabilized, but the tunnel excavation device is blocked and cannot travel in reverse

Engineering Contradiction:

Improvetunnel structure stabilityVSAvoiddevice reverse travel capability

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The cutter head is designed with collapsible peripheral plates that can dynamically change the outer diameter. During excavation, the peripheral plates are extended to maximize cutting diameter. When reverse travel is needed, the peripheral plates collapse inward to reduce the overall diameter, allowing the device to pass through the narrowed tunnel section after concrete spraying and timbering support.

Inventive Principle:

Principle #15Dynamics

2Productivity

If the tunnel excavation device maintains a large diameter for effective rock cutting, then excavation efficiency is improved, but the device cannot navigate curved paths or reverse travel in narrowed tunnels

Engineering Contradiction:

Improveexcavation efficiencyVSAvoiddevice maneuverability in curved and narrowed sections

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The peripheral plates are designed to be collapsible rather than fixed, allowing the cutter head to dynamically adjust its diameter. This dynamic structure enables the device to maintain large diameter during excavation for high productivity, then collapse to small diameter for navigating curved paths and reversed travel, achieving both excavation efficiency and maneuverability.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The cutter head is segmented into a central core structure and detachable peripheral plates. This segmentation allows the peripheral plates to be independently collapsed or extended, providing flexibility in diameter adjustment while maintaining the structural integrity of the central core during both excavation and reverse travel operations.

Inventive Principle:

Principle #1Segmentation

3Ease of manufacture

If conventional fixed-diameter cutter heads are used, then the structure is simple and easy to manufacture, but the device cannot adapt to varying tunnel diameters required for reverse travel

Engineering Contradiction:

Improvecutter head manufacturing simplicityVSAvoiddiameter adjustment capability

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The cutter head is divided into a simple central core and separate peripheral plate components. This segmentation maintains manufacturing simplicity for each individual component while enabling the complex function of diameter adjustment through the assembly and disassembly of these components. The peripheral plates can be manufactured as separate units and attached to the core structure.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The peripheral plates are designed to nest around the central core structure when collapsed, similar to nested dolls. This nesting configuration allows the cutter head to maintain a compact form factor when reverse travel is needed, while easily expanding to full diameter during excavation by unfolding the peripheral plates outward from the core.

Inventive Principle:

Principle #7Nested doll (Nesting)

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 the tunnel excavation device to travel in reverse and navigate curved paths, overcoming the limitations of conventional devices by adjusting its diameter and maintaining stability during excavation.

Implementation Method 1

a collapsing section (51, 41, 27) provided to an outer circumference of the front body section (11) and capable of collapsing inward

Methodology Applied

Scientific EffectMechanical Collapse:

Implementation Method 2

The rear body section (12) includes a gripper section (70). The gripper section (70) obtains a reaction force for performing excavation

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS12435629B2Tunnel excavation device

Publication Date: 2025.10.07 KOMATSU LTD

AI summary

A tunnel excavation device includes a front body section and a rear body section. The front body section includes a cutter head, a cutter head support, peripheral plates, a roof shoe, and side shoes. The cutter head includes a plurality of roller cutters. The cutter head support supports the cutter head. The peripheral plates, the roof shoe, and the side shoes are provided to the outer circumference and can be collapsed inward. The rear body section is disposed to the rear of the front body section. The rear body section includes a gripper section. The gripper section obtains a reaction force for performing excavation.