Shell mould having a heat shield

Patent metadata

Field	Value
Publication number	US-9643240-B2
Application number	US-201314429109-A
Country	US
Kind code	B2
Filing date	Sep 16, 2013
Priority date	Sep 25, 2012
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

A field of casting, and more particularly to a shell mold, and also to methods of fabricating and using such a shell mold. This shell mold includes a central cylinder, a plurality of molding cavities arranged in an assembly around the central cylinder, and at least one heat shield that is substantially perpendicular to the main axis. The central cylinder extends along a main axis between a casting cup and a base. Each molding cavity is connected to the casting cup by at least one feed channel, and also, by a baffle-selector with a starter in the base. The at least one heat shield completely surrounds each molding cavity in a plane that is substantially perpendicular to the main axis.

First claim

The invention claimed is:

1. A shell mold comprising:
a central cylinder extending, along a main axis, between a casting cup and a base;
a plurality of molding cavities arranged as a cluster around the central cylinder, each one being connected to the casting cup by at least a feed channel, and via a baffle-selector to a starter in the base;
at least one heat shield that is substantially perpendicular to said main axis;
wherein said at least one heat shield completely surrounds each said molding cavity in a plane that is substantially perpendicular to said main axis; and
wherein said at least one heat shield presents a through orifice around each molding cavity.

2. A shell mold according to claim 1 , comprising at least two heat shields that are substantially perpendicular to said main axis, with an offset between them in the direction of said main axis, and each completely surrounding each said molding cavity in a plane that is substantially perpendicular to said main axis.

3. A shell mold according to claim 1 , wherein said at least one heat shield includes stiffeners.

4. A method of fabricating a shell mold according to claim 1 , comprising the following steps:
making a non-permanent cluster comprising a plurality of models connected by a tree;
dipping the cluster in a slip;
dusting the slip-coated cluster with refractory sand in order to form a shell around the cluster;
removing the cluster; and
baking the shell.

5. A method of fabricating a shell mold in accordance with claim 4 , wherein each heat shield is formed around a non-permanent disk.

6. A casting method using a shell mold according to claim 1 , comprising the following steps:
casting molten metal into the shell mold through the casting cup; and
progressively cooling the molten metal along said main axis, from the base towards the casting cup.

7. A method according to claim 6 , wherein the step of progressively cooling the molten metal is performed by gradually extracting the shell mold from a heater chamber, along the main axis, in the direction of the base, while cooling the base.

Assignees

• Snecma

Inventors

• Fargeas Serge
• Coyez Dominique

Classifications

• B22D27/04

  Influencing the temperature of the metal, e.g. by heating or cooling the mould · CPC title

• B22D30/00

  Cooling castings, not restricted to casting processes covered by a single main group (accessories for cooling cast stock in continuous casting of metals B22D11/124; controlling or regulating processes or operations for cooling cast stock or mould in continuous casting of metals B22D11/22; chill casting B22D15/00) · CPC title

• B22C9/22

  Moulds for peculiarly-shaped castings · CPC title

• B22C9/04 Primary

  Use of lost patterns · CPC title

• B22D27/045

  Directionally solidified castings · CPC title