Hydraulic Braking Chamber Stroke Control for Percussion Tools

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Solution Overview

Problem

Percussion devices moved by incompressible fluid under pressure are expensive and complex for use in homogeneous terrain, as they require sophisticated systems to adjust striking frequency and energy per blow, leading to potential 'empty blows' and damage.

Innovation Solution

The braking chamber is repurposed to control the piston's stroke, using a spring-loaded control device with calibrated orifices and non-return valves to adjust the fluid flow between chambers, eliminating the need for additional control mechanisms, resulting in a simpler, reliable, and cost-effective design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If sophisticated control systems are used to adjust striking frequency and energy per blow, then the device can adapt to heterogeneous terrain, but the device complexity and cost increase significantly

Engineering Contradiction:
Improveadaptation to terrainVSAvoidcontrol system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The braking chamber is made multi-functional by having it serve both its original braking function and a new function of controlling piston stroke length. The same chamber that provides hydraulic braking also controls the fluid flow to the upper chamber, thereby regulating striking parameters without requiring separate control mechanisms.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The control function for stroke length is merged with the braking function in the same chamber. The braking chamber simultaneously performs both braking operations and stroke control operations, consolidating multiple functions into a single component to reduce overall system complexity.

Inventive Principle:
Principle #5Merging (Combining)

2Productivity

If the device uses high energy per blow settings, then productivity improves on homogeneous hard ground, but the risk of destructive empty blows increases when the tool is not correctly pressed

Engineering Contradiction:
Improveproductivity on hard groundVSAvoidempty blows damage
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The system dynamically adjusts the striking parameters (stroke length and energy) based on real-time operating conditions. The braking chamber automatically modifies the piston stroke length in response to variations in tool contact with the material, enabling the device to adapt between high-energy mode for hard ground and reduced-energy mode to prevent empty blows.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses hydraulic pressure feedback from the braking chamber to automatically regulate piston stroke length. When the tool is not correctly pressed on the material, the hydraulic pressure changes trigger the braking chamber to reduce stroke length, thereby preventing destructive empty blows without requiring external sensors or control systems.

Inventive Principle:
Principle #23Feedback

3Force

If the piston stroke is allowed to extend freely, then the energy per blow increases, but the device cannot protect against empty blows when the tool is not correctly pressed

Engineering Contradiction:
Improveimpact forceVSAvoidprotection against empty blows
Core Design Contradiction:
ForceVSReliability

Solution Approach 1:

The braking chamber acts as a预先 protective mechanism that can reduce piston stroke length before empty blows occur. By monitoring hydraulic pressure conditions, the system proactively shortens the stroke when tool contact is insufficient, preventing damage before it happens rather than reacting after the fact.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The braking chamber autonomously controls the piston stroke length without requiring external intervention. The hydraulic pressure from the system itself provides the feedback signal that triggers the braking chamber to adjust the stroke, making the system self-regulating and eliminating the need for separate control mechanisms.

Inventive Principle:
Principle #25Self-service

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 adaptive control of striking frequency and energy per blow, reducing 'empty blows' and protecting the device, while maintaining efficiency on homogeneous terrain without the need for complex systems, thus enhancing productivity and reducing costs.

Implementation Method 1

a percussion apparatus moved by an incompressible fluid under pressure

Methodology Applied
Scientific EffectHydraulic pressure: Pressure Increase

Implementation Method 2

a braking chamber, which is used to hydraulically stop the stroke of the piston

Methodology Applied
Scientific EffectHydraulic damping: Damping

Implementation Method 3

a spring-loaded control device with calibrated orifices

Methodology Applied
Scientific EffectElastic force: Spring

Data Source

PatentEP2032316B1Percussion equipment driven by a pressurized incompressible fluid
Publication Date: 2013.05.08 MONTABERT SA
  • EP2032316B1 patent drawingFigure 1
  • EP2032316B1 patent drawingFigure 2
  • EP2032316B1 patent drawingFigure 3

AI summary

The equipment comprises a body (2) inside which there are a bore in which a tool (3) is slideably mounted and a stepped bore forming a cylinder for a stepped piston (1) which together with this bore delimits a top chamber (5) and a bottom chamber (4) which chambers are sequentially supplied with incompressible fluid under high pressure under the action of a directional control valve (6), a control device varying the stroke of the striking piston between a long stroke and a short stroke and vice versa. The control device comprises a cylinder into which there opens at least one port (14) which also opens into the cylinder of the striking piston (1), and a port (13) connected to the directional control valve and in which a spool (12) is mounted, a first face of which spool lies in a first chamber (17) constantly subjected to a determined pressure and the second face of which spool lies in a second chamber (21) connected to a braking chamber (10).