Submarine Torpedo Ejection Using Gas Accumulator Cushioning

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Solution Overview

Problem

Conventional systems for ejecting torpedoes from submerged submarines generate noise due to piston impacts, making it difficult to maintain stealth as sonar technology advances.

Innovation Solution

A device utilizing a water piston cylinder with a hydraulic piston cylinder and bladder accumulator, where the gas in the piston accumulator is compressed to generate a counterforce that slows down the piston's braking, reducing noise and allowing rapid rearming.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a hydraulic piston cylinder with water cylinder-piston unit is used for ejection, then the weapon can be ejected more quietly than conventional compressed air systems, but the pistons will strike the end of the piston cylinder producing loud impact noise

Engineering Contradiction:
Improveejection noiseVSAvoidpiston impact noise
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The patent applies beforehand cushioning by introducing a spring mechanism at the end of the piston cylinder stroke. The spring is pre-positioned to engage before the piston reaches the hard stop, gradually absorbing the piston's kinetic energy and reducing the impact noise. This cushioning action occurs in advance of the potential impact, preventing the loud noise that would otherwise be generated by direct piston-cylinder wall collision.

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

Solution Approach 2:

The patent uses a spring as an intermediary element between the piston and the cylinder end wall. Instead of the piston directly impacting the hard cylinder wall (creating loud noise), the spring acts as a mediator that gradually decelerates the piston through elastic deformation. This intermediary mechanism transforms the abrupt impact into a controlled, quieter deceleration process.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-generated harmful factors

If a spring is provided at the end of the piston cylinder to dampen piston movement, then some noise is reduced, but a noise will still occur when the piston hits the spring

Engineering Contradiction:
Improvepiston impact noiseVSAvoidresidual impact noise
Core Design Contradiction:
Object-generated harmful factorsVSObject-affected harmful factors

Solution Approach 1:

The patent applies dynamics by making the cushioning mechanism adjustable and adaptable to varying operational conditions. The spring constant and pre-compression can be modified based on the specific weapon weight and ejection requirements. This dynamic adjustment allows the system to optimize the cushioning effect, ensuring the piston decelerates smoothly without creating significant impact noise while maintaining effective ejection performance across different scenarios.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent utilizes parameter changes by varying the spring characteristics (stiffness, pre-compression force, material properties) to optimize the noise reduction effect. By carefully selecting and adjusting these parameters, the system achieves a balance where the spring engages the piston gently enough to minimize impact noise while still providing sufficient deceleration force. The parameters can be tuned based on specific operational requirements to further reduce residual noise.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If conventional compressed air systems are used for ejection, then the system is simple, but the ejection produces loud noise making it easy to locate the submarine

Engineering Contradiction:
Improvesystem simplicityVSAvoidejection noise
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent transitions from pneumatic (compressed air) to hydraulic (water-based) propulsion for the ejection system. Water is incompressible, allowing for smoother, more controlled piston movement and weapon ejection. The hydraulic system uses water pressure to drive the piston, which can be better regulated and controlled compared to compressed air. This hydraulic approach, combined with the spring cushioning mechanism, significantly reduces ejection noise while maintaining system effectiveness, addressing the noise issue that plagues simpler pneumatic systems.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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

The device achieves quiet ejection and rapid rearming by using the compressed gas to slow down the piston's braking, minimizing noise and enabling quick readiness for subsequent ejections.

Implementation Method 1

the gas in the gas section of the piston accumulator is continuously compressed. While the weapon is fired, hydraulic fluid is simultaneously pumped from the hydraulic piston cylinder into the piston accumulator, compressing the gas in the gas section therein

Methodology Applied
Scientific EffectGas compression: Compression

Implementation Method 2

The pressure increases due to the compression of the gas in the piston accumulator. Assuming an ideal gas, this increase can be approximated by the ideal gas law p · V = n · R · T

Methodology Applied
Scientific EffectGas pressure: Pressure Increase

Implementation Method 3

the weapon is fired by hydraulic fluid from the bladder accumulator driving the second piston and thus indirectly the first piston, thereby forcing the water into the gun barrel

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Data Source

PatentEP3408604B8Noiseless weapon ejection system
Publication Date: 2019.11.20 THYSSENKRUPP MARINE SYST GMBH

AI summary

The invention relates to a device for ejecting a weapon (32), in particular a torpedo, out of a weapon tube (30), in particular out of a submerged submarine, wherein the ejection occurs with significantly reduced noise compared to conventional systems. The invention further relates to a device for ejecting a weapon (32), in particular a torpedo, from a weapon tube (30), in particular from a submerged submarine, wherein the readiness of the device to fire after the ejection of a weapon (32) can be restored in an accelerated manner.