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
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D25/00—Special casting characterised by the nature of the product
  • B22D25/02—Special casting characterised by the nature of the product by its peculiarity of shape; of works of art
• • 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
  • B21J5/002—Hybrid process, e.g. forging following casting
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21K—MAKING FORGED OR PRESSED METAL PRODUCTS, e.g. HORSE-SHOES, RIVETS, BOLTS OR WHEELS
  • B21K21/00—Making hollow articles not covered by a single preceding sub-group
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D31/00—Cutting-off surplus material, e.g. gates; Cleaning and working on castings
  • B22D31/002—Cleaning, working on castings

Definitions

• the invention relates to the technical sector of hot or cold forging for making hollow parts of light alloys.
• the invention also refers to the technical sector of the foundry in which it is known to melt the material around a core previously disposed and held in a mold.
• the invention relates to the application of the method for all technical fields for producing parts with high mechanical characteristics and in particular for certain parts or components in the automotive field, the cycle not limited.
• the technology of hollow part forging is well known. This is for example the case of forging ingots of previously pierced material. It is also the radial forging of blanks or forging ingots requiring time and several forging steps. We also know the forging of hollow parts with implementation of pins that allow the realization of recesses. This technique requires the use of pin insertion mechanisms and an automatism that can operate at the rate of hammers for good productivity.
• these recesses are always apparent to allow the positioning of the pins, and create limitations of use.
• the kinematics to calculate is not always easy to implement. We also know the machining method of the parts but it is expensive in machining time and initial material to be machined.
• Patent EP 850825 does not take into account the possibility of deformation of the core during the striking operation during forging. This patent is limited to pedal cranks for cycle in which the stresses are quite different than those resulting from the technical components for the design of motor vehicles.
• the bearing surfaces associated with the core are arranged in the zones to be machined.
• the method described in the patent requires that it is necessary to drill, pre-machine the piece obtained to break the core. This constraint is very heavy and delicate to achieve. The operator must also cut the final piece. The trimming results in the recovery of various and incompatible materials such as aluminum and steel, the aluminum being contained in the forged flash and the steel being the constituent material of the sealing means (pins, worn-inserts). This requires in the hypothesis of recycling a sorting.
• the process for manufacturing hollow parts made in two successive operations of material casting for the production of a semi finished product then forging implements the following operating phases: a) definition of the final hollow part in its inner part to obtain after forging with deformation of solid or drawn sections according to environmental and mechanical constraints, b) modeling of solid and drawn sections in areas of the part requiring it
• step d) Modeling deformations introduced by forging, e) With the result of step d) modeling of the part and its core before forging, that is to say of the casting, and the core in its initial form f) After pouring the metal around said core (s) (x) over all or part of their volume into the initial shape that makes it possible to obtain a semi-finished product with its nucleus (s), this type of striking operation semi-finished product with its nucleus (s) generating deformation of the part and its nucleus (s) from their initial forms to their final shapes, (g) Trimming of the burrs made of the casting material, (h) Evacuation of the monolithic kernel (s) recyclable material,
• the modeling step of the functional zones of the core provides that the functional zones of the core emerging at the surface of the part after forging must be located outside the clipping areas of the part, in particular outside the joint plane of the dies forging, and sufficiently far away from them, to allow trimming without removing material from the core,
• Figure 1 is a perspective view of a plurality of cores for insertion into a casting and forging. (1) are mono-material comprising their bearings (la) ensuring their positioning in the mold.
• Figure 2 is a view illustrating the cores positioned in the foundry mold before performing the casting operation.
• Figure 3 is a sectional view illustrating the semi-finished product (2) obtained after casting, with the two cores positioned in the areas drawn in thickness.
• FIG. 3 A is identical to Figure 3, but with a hatch representation for the understanding of the drawing
• FIG. 4 is a view of a finished forging (3) with areas including cores (1) in thick drawn parts and solid areas.
• ⁇ 4A is the same as Figure 4, but with a hatch representation for the understanding of the drawing,
• Figure 5A1 is identical to Figure 5A, but with a hatching representation for the understanding of the drawing,
• Scheme 5B1 is identical to Scheme 5B, but with a hatch representation for good understanding of the drawing.
• the method according to the invention is distinguished from the prior art by the initial modeling operations of the part including one or more cores (1) mono-material and recyclable and integrating into the same material their bearing (la) positioning .
• These modeling operations allow the definition of parts of parts that must be full and those that have thick drawn by the placement of the cores.
• Upstream modeling combined with the mastery and knowledge of the characteristics of the materials constituting the part and the core or cores make it possible to simulate the flow of the metal around the core or cores which deform during the forging. This allows the optimization of the shape of the cores or placed in the room for its implementation by casting and forging.
• the control of all these data allows us to define the part according to the desired thicknesses
• the method according to the invention also implements a software of values integrating all the data relating to the finished part to obtain, all the data of the core or nuclei, all the data relating to the machine or striking tools, said software calculating the set of deformations of the piece and the nucleus or nuclei to define the initial and final forms to obtain.
• Modeling makes it possible to have no internal defect because the initial shape of the nucleus or nuclei is defined beforehand to meet this objective, for example, the types of defects, release of the core in the burr or drawn of inhomogeneous thickness over any section, can not arrive.
• the modeling makes it possible to have no apparent external defect type withdrawal, trace of crude for example.
• the burr obtained after forging remains exclusively in the casting material and can be easily cut and recycled.
• the method according to the invention also makes it possible to define, among other things, an optimization of the stiffness and, on the other hand, to reduce the weight without deteriorating the behavior of the part.
• the core (s) (x) (1) are further selected and defined with a compression ratio of less than 0.30 to 1500 MPa.
• the core or cores may be of different materials, especially made of sand, but in an optimized version of salt as needed but each core is mono-material. It is possible to recover fully after unstacking the nucleus according to the known methodologies.
• the core can be removed in particular by thermal deburring or mechanical deburring when it is sand, or air / water pressure if the core is in salt.
• the evacuation of the nucleus (s) is carried out conventionally by means of orifices provided on the shell and the striking matrix.
• the solution provided thus allows optimization of the manufacture of hollow light alloy parts in whole or part of their volume by the implementation of the casting of the alloy and the forging of the part.
• the same part treated by the process according to the invention can have, according to the modelizations, a single hollow zone for the reception of a core, a plurality of alternating hollow zones with solid zones, the hollow zones receiving cores in corresponding number.
• the staves (la) can be multidirectional.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Forging (AREA)
• Molds, Cores, And Manufacturing Methods Thereof (AREA)

Priority Applications (10)

Applications Claiming Priority (2)

Publications (1)

Family

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Family Applications (1)

Country Status (13)

Families Citing this family (9)

Citations (6)

Family Cites Families (10)

• 2010
  • 2010-04-06 FR FR1052586A patent/FR2958193B1/fr not_active Expired - Fee Related
• 2011
  • 2011-04-05 CN CN201180017871.9A patent/CN102917815B/zh active Active
  • 2011-04-05 RU RU2012146973/02A patent/RU2578282C2/ru active
  • 2011-04-05 BR BR112012025340-9A patent/BR112012025340B1/pt active IP Right Grant
  • 2011-04-05 ES ES11719334.2T patent/ES2505499T3/es active Active
  • 2011-04-05 PT PT117193342T patent/PT2555886E/pt unknown
  • 2011-04-05 RS RSP20140502 patent/RS53538B1/sr unknown
  • 2011-04-05 PL PL11719334T patent/PL2555886T3/pl unknown
  • 2011-04-05 EP EP11719334.2A patent/EP2555886B1/fr active Active
  • 2011-04-05 HR HRP20140914AT patent/HRP20140914T1/hr unknown
  • 2011-04-05 US US13/638,945 patent/US8701741B2/en active Active
  • 2011-04-05 JP JP2013503156A patent/JP5850910B2/ja active Active
  • 2011-04-05 WO PCT/FR2011/050757 patent/WO2011124836A1/fr not_active Ceased

Patent Citations (6)

Non-Patent Citations (1)

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