Rail Vehicle Sandbox Shutter Inversion for Sand Flow Control

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Solution Overview

Problem

Existing sandbox systems for rail vehicles face challenges in continuously controlling the translatory motion of the shutter, leading to incomplete closing due to sand grains, wear, and discontinuous sand flow adjustment, which affects the reliability and maintenance of the system.

Innovation Solution

A cylindrical shutter with a ring-shaped sealing seat and a concave lower face, combined with a spreader element for air injection and heating, allows for continuous sand flow adjustment and prevents grain trapping, enabling precise control and ease of maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional shutter with a closing plate or cone is used, then the sand flow can be controlled, but sand grains become trapped between the shutter and the seat during closing operation, preventing complete closing

Engineering Contradiction:
Improvecomplete closing of shutterVSAvoidgrain trapping during closing
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

Instead of using a conventional closing plate or cone that closes from the top, the invention uses an inverted conical seat where the small diameter is at the top and the large diameter is at the bottom. The shutter closes from below, inverting the traditional closing direction, which prevents sand grains from being trapped during the closing operation.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The invention employs a conical (curved) seat geometry instead of a flat closing plate. The inverted cone shape with its curved surface allows sand grains to slide off easily during closing, preventing trapping while maintaining effective sealing when the shutter is closed.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Productivity

If the shutter is controlled to open and close completely without intermediate positions, then the system is simple, but continuous sand flow adjustment cannot be achieved

Engineering Contradiction:
Improvecontinuous sand flow adjustmentVSAvoidcontrol system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The invention makes the shutter position dynamic and continuous rather than binary (open/closed). The actuator can position the shutter at any intermediate level, allowing continuous adjustment of sand flow rate. This dynamic positioning capability enables precise control of sand delivery while maintaining relatively simple system architecture.

Inventive Principle:
Principle #15Dynamics

3Reliability

If the shutter operates between upper closed position and lower opened position, then the sand flow can be controlled, but the actuator bears the weight of sand and experiences untimely wear

Engineering Contradiction:
Improvereduction of wearVSAvoidweight of sand on actuator
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The invention inverts the closing mechanism so that the shutter closes from below rather than from above. This inversion changes the force distribution, allowing the actuator to operate with reduced sand weight burden. The inverted conical seat geometry also facilitates easier opening by allowing sand to fall away from the closing surface.

Inventive Principle:
Principle #13The other way round (Inversion)

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 solution ensures reliable and continuous sand flow adjustment, reduces wear, and simplifies maintenance by preventing grain trapping and facilitating fluid sand flow, while maintaining antifreeze and drying functions.

Implementation Method 1

a spreader element (14), i.e. a torus featuring a rectangular section made of a porous material, for instance syntherized bronze, which surrounds a hollow body (10)

Methodology Applied
Scientific EffectFluidisation: Fluidisation

Implementation Method 2

a spreader element (14), i.e. a torus featuring a rectangular section made of a porous material, for instance syntherized bronze, which surrounds a hollow body (10)

Methodology Applied
Scientific EffectCompressed air injection: Pressurisation

Implementation Method 3

the sand inside the container (1) can be heated by a heating device which performs an antifreezing and drying function

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 4

Sand descent and jet are provided by a pneumatic system which, outside the container, speeds up the sand coming out of the valve assembly, so as to impart such a speed to it as to reach the final destination

Methodology Applied
Scientific EffectJet: Jet

Data Source

PatentEP3154841B1Sandbox for rail vehicles
Publication Date: 2020.03.18 TELESIA MICROELETTRONICA
  • EP3154841B1 patent drawingFigure 1
  • EP3154841B1 patent drawingFigure 2~3
  • EP3154841B1 patent drawingFigure 4

AI summary

The invention relates a sandbox for rail vehicles, of a type comprising a sand container, on the bottom of which there is a hollow body which presents one or several openings through which sand flows out towards an ejector assembly beneath by passing through an outler hole controlled by an axially sliding vertical shutter located inside said hollow body and means handling and controlling said shutter which cause its translation between a lower position in which said output hole is closed and an upper, maximum opening position, whereby said shutter features a cylindrical shape and its lower end functionally copperates with a ring shaped, sealing coaxial seat, corresponding to said outlet hole of said container.