Percussion Hammer Control Piston for Tap Hole Drilling

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing rotary hammer mechanisms for metallurgical vessels lack simple and effective control over impact frequency and force, making it difficult to adapt to varying operational requirements and potentially causing damage to refractory linings during tap opening and closing processes.

Innovation Solution

A hammer mechanism with a cattail and adjustable transmission part, featuring a control recess and axially offset grooves in the housing, allows for controlled displacement and reversal of the pressure medium, enabling adjustable impact frequency and force by activating different reversing grooves through a control means, which can be manually or automatically adjusted.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the quantity per unit of time and/or pressure of the supplied pressure medium is adjusted to control impact energy and frequency, then the impact parameters can be controlled, but the control system becomes complex

Engineering Contradiction:
Improveimpact frequency and force controlVSAvoidcontrol system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent employs a movable control element that can be positioned at different axial locations within the control recess to dynamically adjust the flow path length. This dynamic positioning mechanism allows simple adjustment of impact frequency and force by changing the control element's position, rather than requiring complex control systems. The control element's movement directly modifies the pressure medium flow characteristics, providing an intuitive and simple control approach.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the flow path length parameter of the pressure medium by adjusting the control element's axial position. This single parameter change (flow path length) directly influences both impact frequency and impact force, allowing control of multiple impact parameters through a simple geometric adjustment rather than a complex control system.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If high impact frequency and low impact force are used to open the tap hole, then the drilling process is optimized, but the tool may jam during retraction

Engineering Contradiction:
Improvedrilling process efficiencyVSAvoidtool extraction reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent enables dynamic adjustment of impact parameters between drilling and retraction phases. During drilling, the control element is positioned to provide high frequency, low force. During retraction, the control element is repositioned to provide low frequency, high force, ensuring reliable tool extraction without jamming. This dynamic adaptation resolves the contradiction between optimized drilling and reliable extraction.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention applies periodic impact actions with different characteristics for different phases of operation. High-frequency periodic impacts are used during drilling to efficiently create the tap hole, while low-frequency high-force periodic impacts are applied during retraction to prevent jamming. This periodic variation in impact characteristics optimizes both drilling efficiency and extraction reliability.

Inventive Principle:
Principle #19Periodic action

3Productivity

If high impact energy is applied during tool advancement, then drilling speed increases, but damage to refractory linings occurs

Engineering Contradiction:
Improvedrilling speedVSAvoidmasonry damage
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the impact energy parameter by adjusting the control element's position to modify the pressure medium flow path length. This allows reduction of impact energy to low levels during drilling to prevent masonry damage, while maintaining adequate drilling speed through optimized lower-energy impacts. The parameter change approach enables precise control of impact energy to eliminate harmful effects.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention applies localized quality control by directing modified pressure medium flow specifically to the impact generation mechanism. The control element's position adjusts the flow characteristics locally at the point of impact generation, creating tailored impact conditions (low energy, high frequency) precisely where needed for drilling, without affecting other system functions.

Inventive Principle:
Principle #3Local quality

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 allows for precise control of impact parameters, optimizing the drilling process by reducing masonry damage and ensuring smooth tool extraction, with adjustable impact energy and frequency for both advancing and retracting the tool, enhancing operational reliability and efficiency.

Implementation Method 1

a piston (1) in a percussion mechanism housing (2) that can be acted upon axially on both sides with a pressure medium

Methodology Applied
Scientific EffectPressure medium application: Pressure Increase

Implementation Method 2

a means for reversing the pressure application to the piston (1), wherein the piston (1) has substantially radial pressure surfaces on both sides that can be pressurized with the pressure medium and has grooves between the piston (1) and the percussion mechanism housing (2) for reversing the pressure medium application to the pressure surfaces

Methodology Applied
Scientific EffectPressure reversal: Pressure Gradient

Implementation Method 3

one of the reversing grooves (3, 3') can be activated by axially positioning a control piston (43) in the recess (41)

Methodology Applied
Scientific EffectPressure medium actuation: Pressure Increase

Implementation Method 4

the control piston (43) can be positioned manually or against a spring force by means of a pressure medium in the recess (41) of the control means (4)

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP2574874B1Striking mechanism for a hammer device and method for opening a tap hole
Publication Date: 2019.04.03 TMT BBG RES & DEV
  • EP2574874B1 patent drawingFigure 1

AI summary

The impact tool has a tubular piston (1) that is structured and arranged for axial displacement in impact tool housing (2) via a pressure medium. The radial pressure surfaces (11,11) are structured and arranged on opposite portions of tubular piston to be acted on with pressure medium. The grooves are provided with a control recess formed in tubular piston and two control grooves (3,3) for shift of pressure medium impingement on pressure surfaces. A controller (4) is structured and arranged to alternatively activate two control grooves via connection channels (42,42). An independent claim is included for method for opening tapping opening in wall of metallurgical vessel provided with fire-proof in-feed using impact tool.