EP0586314B1 - Method of making pieces of casting alloys with reinforced parts - Google Patents

Abstract

The method is noteworthy in that, after producing the blank of the component to be obtained, it employs one or more inserts capable of being centred and introduced into the opening or openings (1.1), and/or the recess or recesses, and/or the blind hole or holes (1.2) formed beforehand in the blank, the said inserts being prepositioned on a work die (3), and in that there next follows an operation of striking by a punch (5) or similar means making it possible to create the final shape of the component to be obtained and to deform the material for the purpose of the fixed and permanent integration, by crimping the insert or inserts (2), so as to define local reinforcement areas depending on the requirements and the applications and uses of the component obtained. <IMAGE>

Description

The invention relates to a method for manufacturing parts from cast alloys and in particular aluminum, aluminum alloy with reinforcement zone.

The invention relates to the technical sector of the production of parts in cast alloys and in particular in aluminum, copper or others obtained in foundry, forging and similar processes.

Foundry and forging techniques make it possible to manufacture multiple parts for various uses. The foundry of cast alloys such as aluminum has the particular advantage of obtaining light parts while respecting the parameters and hardness criteria according to the applications considered. These parts can be, for example, connecting rods for automobiles, cranks for cycle parts.

These parts have coupling zones with other elements or means such as axes or the like and are thus arranged with openings.

Depending on the stresses on the parts in question, it may be necessary to envisage strengthening the connection and coupling zones to avoid deformation of the material during the transmission of forces. According to the technique known in foundry, inserts made of metallic or other material are thus established, for example in the form of rings and which are introduced into the abovementioned openings of the part. To ensure their hold and fixing, one then proceeds to a casting operation of the alloy such as aluminum which while cooling ensures the maintenance of the insert. This the latter may have ridges on its outer periphery or grooves for anchoring the material making it possible to stabilize the insert in the workpiece in position.

This process is widely developed but it has a number of drawbacks or limitations.

The use of the method is essentially limited to the installation on the part of a single insert. Indeed, the operation of casting the alloy and in particular the aluminum being carried out hot causes dimensional variations of the material and it is almost impossible to control with great precision the spacing of laying of several inserts.

In addition, the latter must be chosen from a material or material which is compatible with the temperature of the cast alloys and in particular of aluminum.

These main drawbacks thus prevent the production and implementation of several inserts on parts obtained in aluminum casting and other alloys such as, for example, connecting rods for cars which are coupled at each of their ends to cooperate with the crankshafts and pistons of the block. engine.

It is obvious that these drawbacks are encountered in other applications of the same type.

The aim sought after according to the invention was to remedy these drawbacks.

The applicant has also developed a process for manufacturing aluminum parts in foundries, in particular described in European patent n ° 119365. This process consists in making foundry blanks which are subjected to cold or low temperature to an additional pressing operation, said blanks being arranged in the matrix imprints of dimensions substantially smaller than those of the molding.

As part of its additional research, and in view of the problem originally posed, the applicant has developed a particular method of fitting an insert into parts obtained in a foundry of cast alloys and in particular aluminum, this method being simple, quick to implement and allowing the simultaneous introduction of one or more inserts on the same part, avoiding the drawbacks encountered by the prior art.

It is known according to the prior art defined in patent US-A-3443617 to incorporate inserts in castings, this patent describing a process allowing a press fit of the insert and crimping by creep. This process leads to many manufacturing constraints.

The method according to the invention is defined in claim 1.

• la figure 1 est une vue à caractère schématique de face montrant les éléments mettant en oeuvre le procédé avant l'opération de frappe.
• La figure 2 est une vue selon la figure 1 de la pièce obtenue après l'opération de frappe.
• La figure 3 est une vue illustrant le positionnement de l'ébauche de la pièce dans la matrice de mise en forme avant l'opération de pressage.
• La figure 4 est une vue selon la figure 3 illustrant la pièce après opération de frappe à l'intérieur de l'ensemble matrice poinçon.
• La figure 5 est une vue partielle illustrant une forme d'insert intégré dans la pièce finie obtenue après la mise en oeuvre du procédé par l'invention.
• La figure 6 est une vue partielle en variante illustrant une autre forme d'insert.
• La figure 7 est une vue en plan et en coupe d'une autre forme d'insert avec des rainures établies sur périphérie extérieures dans son plan longitudinal.
• La figure 8 est une vue en variante d'un autre profil de l'insert.

An example of implementation of the method according to the invention and other preferential characteristics will emerge clearly from the following description which refers to the following figures:

• Figure 1 is a schematic front view showing the elements implementing the method before the striking operation.
• Figure 2 is a view according to Figure 1 of the part obtained after the striking operation.
• Figure 3 is a view illustrating the positioning of the blank of the part in the shaping die before the pressing operation.
• Figure 4 is a view according to Figure 3 illustrating the part after striking operation inside the punch die assembly.
• Figure 5 is a partial view illustrating a form of insert integrated into the finished part obtained after the implementation of the method by the invention.
• Figure 6 is an alternative partial view illustrating another form of insert.
• Figure 7 is a plan view in section of another form of insert with grooves established on the outer periphery in its longitudinal plane.
• Figure 8 is an alternative view of another profile of the insert.

In order to make the object of the invention more concrete, an embodiment is now described, illustrated in the figures of the drawings.

The method according to the invention consists in manufacturing parts produced in the foundry of cast alloys and in particular aluminum of all shapes and profiles suitable according to the applications by producing blanks referenced as a whole by (1).

A blank is shown in Figure 1, and includes example a through opening (1.1) and a blind hole (1.2). It is obvious that said blank can have several through openings and / or several blind holes. The profile and dimensions of the openings and / or blind holes are established in any suitable manner according to the needs and criteria of application of the rough parts. The blank can also have any recess on one of its faces of any shape and profile required.

The blank thus has a preset length (L) and a preset thickness (E).

The openings and / or holes and / or recesses advantageously have a substantially conical internal profile of a few degrees at an angle (α) to allow prepositioning of the blank and the reception of one or more inserts (2) of complementary profile. arranged and presented beforehand on a work receiving matrix (3). This matrix is established in any way and appropriate profile according to the shapes of the worked blank.

Said matrix is thus arranged directly or in an attached manner with one or more fingers (4) for centering and receiving the inserts (2). The latter are mounted with play or floating around said finger (s) (4). As a variant, the matrix can be directly shaped to allow centering and positioning of the inserts (2).

The inserts are positioned on the fingers or directly on the matrix manually by the operator or also in the context of manufacturing automation with manipulators and all appropriate means ensuring their transfer from a dispensing bowl or similar means.

FIG. 3 shows the positioning of the blank in the matrix, said blank being adjusted by the opening (s) and the blind hole (s) with free adjustment. The blank is centered in a cavity established on the working die, being of dimensions substantially smaller than the internal profile thereof.

The method according to the invention then consists in exerting a striking operation on the blank using a punch (5) or similar means by exerting this force according to the arrow F arranged axially in the same plane as that of laying inserts. During this striking operation corresponding to FIG. 4, the blank of the treated part is thus deformed and the material comes to surround said inserts while ensuring their final connection by crimping. The finished part is then of a dimension (L1) substantially greater than that (L) of the blank, and its thickness (E1) is substantially less than that (E) of the blank. Thus, the interior cavity of the matrix initially receiving and completely filled by the finished part.

Referring to FIG. 2, the part obtained integrates the inserts into the above-mentioned opening (s) and / or the blind hole (s), and / or the recesses (not shown).

Referring to Figure 5, the insert can be established in the form of a ring having a collar (2.1). In this embodiment the ring is of height (H) substantially less than the thickness (E1) of the finished part; thus said ring is held by the material both at the level of its zone presenting the collar, as well as in its bottom part. In the case of adaptation of the insert in a blind hole, said insert has a bottom face (2.4).

Referring to Figures 6 and 7, the ring may have circular ridges (2.2) arranged along its outer periphery under all or part of its height. The ring can also have one or more longitudinal grooves (2.3) established over all or part of its periphery. These striations and grooves thus constitute means for anchoring the blank material resulting from the deformation thereof during the striking operation.

Referring to Figure 8, there is shown another form of the insert which may have a cross shape or any other.

The shape of the insert (s) is unlimited and inserts of different shape can be placed on each part to be obtained without departing from the scope of the invention as claimed.

The insert (s) can be made of any metallic, composite or other material.

When the striking operation has been carried out, the punch is raised by any appropriate means and the finished part is ejected in order to carry out a new operating cycle.

The advantages emerge clearly from the invention. We highlight a new ability to easily and quickly have one or more inserts in any foundry blank in order to proceed with their integration. It is thus easy to arrange on the blank and the part to be obtained different local reinforcement zones. according to the needs and applications of the different constraints on the part. It suffices for this during the manufacture of the blank to provide one or more openings and / or recess and / or blind holes of any suitable shape allowing the insertion of inserts with the complementary profile during a single striking operation . Such a process is perfectly adaptable in the context of production automation.

Claims (6)

1. Manufacturing process for components made of cast alloys, especially aluminium and aluminium alloy, with a reinforcement area, said components having holes or cavities to cooperate with means of coupling and one or more inserts (2) fitted into said openings or cavities and integrated into the component by squeezing during a punching operation using a punch (5) or similar means and a working die (3) to form reinforcement areas, in which process the rough casting part (1) is produced having one or more through holes (1.1) and/or one or more blind holes (1.2) and/or one or more recesses formed on the surface of the rough casting (1) intended to be offered up opposite the working die (3), said holes (1.1) and/or blind holes (1.2) and/or recesses having a profile tapered by several degrees making it possible to accommodate and pre-centre one or more of said inserts (2),
      and wherein, after producing the rough casting (1) of the component to be obtained, there are arranged one or more inserts (2) capable of being centred and inserted into the hole(s) (1.1) and/or the recess(es) and/or blind hole(s) (1.2) previously formed on rough casting (1), said inserts (2) being pre-positioned on working die (3),
      and wherein said inserts (2) are used to position and centre the rough casting (1) in an accommodating cavity in the working die (3) which corresponds to the final shape of the finished component, said rough casting (1) having dimensions slightly smaller than the internal profile of the cavity which will be completely filled by the finished component,
      and wherein a punching operation is then performed on rough casting (1) positioned and centred in said accommodating cavity by punch (5) or similar means allowing final shaping and deformation of the material of rough casting (1) in die (3) with a view to securely and permanently integrating the insert(s) (2) by squeezing in order to define local reinforcement areas as needed and depending on the applications and uses of the component obtained.
2. Process as claimed in claim 1, characterised in that inserts (2) are pre-positioned with a loose fit.
3. Process as claimed in claim 1, characterised in that inserts (2) are pre- positioned directly on the working die (3).
4. Process as claimed in claim 1 characterised in that rough casting (1) has a predefined length (L) and thickness (E), the finished component obtained from the rough casting (1) having a length (L1) that is slightly smaller than that (L) of the rough casting (1) and a thickness (E1) slightly less than that (E) of rough casting (1).
5. Process as claimed in claim 1, characterised in that insert (2) consists of a ring shape and has a neck (2.1), the height of the ring being less than the thickness (E1) of the finished component.
6. Process as claimed in claim 1, characterised in that the inserts (2) are pre- positioned on centring pins (4) formed on the working die (3).

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