Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
  • B21J5/00—Methods for forging, hammering, or pressing; Special equipment or accessories therefor
  • B21J5/02—Die forging; Trimming by making use of special dies ; Punching during forging
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
  • B21J13/00—Details of machines for forging, pressing, or hammering
  • B21J13/02—Dies or mountings therefor

Definitions

• the invention which is the object of this application concerns a production method (and the produced elements) which consists in fabricating moulds, dies or any other unique pieces or small series (always metallic pieces or compounds with a metallic basis) by means of a closed forge.
• a concrete or mortar forming mould is used (in particular, concretes or mortars made of high resistant concretes and/or refractory material on the basis of porcelanates, corundum, silicates... and with basalt aggregates, silicon oxides, or other aggregates which normally are applied in construction, or aggregates on the basis of aluminium or other refractory materials).
• the main concern of this invention is the drastic cost reduction and time saving by using a closed forge to produce metallic pieces with a complex geometry.
• the present invention obtaining moulds, dies and small series
• the production costs of the forming mould are not excessively high.
• Another point of concern is the possibility of forming materials, on a metallic basis, which are difficult to machine or which cannot be machined, but which have on the other hand in hot condition sufficient yielding in order to be shaped trough forging.
• mould or die Any element which is used to form or shape metallic pieces, polymers, ceramics or composites of these is considered a mould or die.
• the form of a mould or die can be the negative of the piece which has to be produced as is the case with injection moulding, pressing, dies for deep drawing, bending, stamping or any other method of shaping. It can also be a bent section as is the case with some cutting dies).
• the mould or die can be used in order to get just on piece or, as usual, hundreds up to millions of pieces by repeated actions. Very often, they are also used to get more than one piece with each step of shaping.
• ANNOTATION TO CLARIFY TERMINOLOGY Very often "shaping or forming” is understood in the industrial sector of sheet stamping as a very concrete operation which consists in deforming a plane sheet until the sheet acquires a definite shape (generally, the final piece). This can be reached with one or more operations.
• shape or forming is used to designate any operation in which a material is deformed by a mould or a die (examples of operations designated as “shaping or forming” are: cutting, stamping, deep drawing, hot forging, cold forging, extrusion, press moulding, gravity moulding, thermal shaping, pressing, blow forming, ... )
• ANNOTATION TO CLARIFY TERMINOLOGY designates any container which is able to give a metallic piece a specific form by means of a closed forge (also generally denominated: forging die, forging mould, forging devices).
• moulds and dies can be distinguished. However, there are not only differences in the application, but also in the kind of materials used to build moulds and dies and in the process:
• a metallic form with the desired geometry is obtained by eliminating the dispensable material (in general, the basic material is a forged block or a block which has been cut from a forged or rolled ingot, however, also melted blocks are used).
• the toughness of a forged alloy is much higher than the toughness of the same alloy in "as melted" or cast state. The higher toughness results very often in a longer life of the produced tool (ANNOTATION: In this document the term “tool” designates moulds and dies at the same time). This method is used to make dies and moulds which should produce high numbers of pieces and which are fairly even (it doesn't take excessive stock removal to attain the desired shape). Machining by stock removal is an expensive process.
• the ingots are then forged in order to convert them into billets.
• the billets are forged or rolled again in order to obtain forged blocks or bars.
• the bars have to be cut in order to get the desired block.
• the block has to be machined by stock removal or electro-erosion in order to obtain the desired geometry.
• the processes before hardening, final machining, ... are common for both production methods.
• the one which is currently most used is the process in which the material is melted in a sand mould and a poly-styrene model which is consumed when the mould is filled.
• a pre-form is obtained.
• the tool has to be machined by stock removal in order to get the appropriate tolerances in the working areas.
• the geometry of the pre-form is similar to the final one.
• less material has to be removed and thrown away.
• moulds and dies can be obtained in a more economic way (when compared to departing from a forged block, the economic difference is bigger when there are big differences in the spot heights and, consequently, the more material has to be eliminated when departing from a solid block).
• those moulds and dies have a lower durability. It is the preferred method if a small quantity of pieces has to be produced and if the variability in the spot heights is high.
• moulds and dies can be obtained as economically and as simply as is the case of casting which is the currently the process most widely used.
• those obtained moulds and dies have the same or even a higher lifecycle as the moulds and dies which are obtained by machining forged or rolled blocks (very often blocks cut off from forged and/or rolled bars).
• the method allows the use of materials which are difficult to machine (even materials which are considered as "not machinable”). With the use of such materials, the lifetime and/or the productivity of the manufactured tools or pieces will be considerably higher.
• the present invention consists in providing a production method for dies, moulds and unique pieces or for a small quantity by means of forging in a forming mould.
• the method consists in the construction of a forming mould which is able to bear high temperatures and mechanical stressing which occur when forging material in a closed system (it does not matter if the forming mould is destroyed during the forging process if the material of the mould, die or piece is deformed; the forming mould is sufficiently economically so that its amount does not exceed the cost reduction regarding the machining process).
• the materials which are used for the construction of the forming mould should be the most economical, but they must have the thermal and mechanical characteristics which are necessary for the forging process.
• mortar and concrete have to be mentioned: with cement of a high resistance (on the basis of porcelanates, silica, ...), with refractory cement (on the basis of alumina, aluminosilicate, ...), with basaltic aggregates, sand (SiO 2 ), and other refractory aggregates (on the basis of alumina), and other aggregates which are normally used for construction.
• mortars can be used (on the basis of MgO, SiC, ZnO, Cr 2 O 3 , ZrO 2 , B 2 O 3 , Al 2 SiO 5 , CeO 2 , C 2 Si 3 , CaF 2 , silica, graphite, magnesite, silicates, lignosulphonates, phosphates (of boron, aluminium, ...)).
• Some of the previously mentioned aggregates can also be used with a binding agent (for instance, aluminium phosphate).
• one part of the invention is used for obtaining moulds and dies by melting, as forming moulds of mortar and concrete are employed.
• the dimension tolerances which can be obtained as well as the quality of the final machining are notably higher.
• the present invention is also a big advantage for obtaining final pieces or pre-forms (in particular, with unique pieces or a small quantity), especially, if the material which is used to get the piece is difficult to machine or if it's of a high cost. Some geometry can not be obtained in a affordable manner unless the method of the present invention is employed, such is the case of very difficult to machine materials as metal matrix composites with ceramic reinforcement.
• the invention also implies an important economic advantage when obtaining sintered pieces in concrete forming moulds, especially, if concrete of a high resistance is used.
• the material of which the mould, die or piece shall be made of is filled into the forming mould as powder.
• cold or hot pressing is executed in order to get the final geometry or the pressed green pre-form, a little bit sintered or totally sintered with or without liquid phase.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Forging (AREA)
• Mounting, Exchange, And Manufacturing Of Dies (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=36498327

Family Applications (1)

Country Status (2)

Cited By (1)

• 2004
  • 2004-11-16 EP EP04798237A patent/EP1892049A1/fr not_active Withdrawn
  • 2004-11-16 WO PCT/ES2004/000510 patent/WO2006056621A2/fr active Application Filing

Also Published As

Similar Documents

Legal Events