FI80620B - Process and device for production of an object or a mould, template or the like for an object - Google Patents

Abstract

The invention relates to a process and a device for the moulding or production of an object, the mould for an object, a template or the like. The manufacturing process according to the invention for three-dimensional objects is characterized in that the metering and/or shaping of a blank 6 containing magnetizable particles 7 is controlled in a magnetic field in order to achieve an object corresponding to the geometric shape of the desired object so that its cohesive force is the magnetic field, the field lines of which run through the magnetic particles forming the desired mould 5. <IMAGE>

Description

80620

METHOD AND APPARATUS FOR MANUFACTURING A PART OR MOLD MOLD, TEMPLATE OR THE LIKE -

The invention relates to a method and an apparatus for forming or manufacturing a body or body mold, template or the like, in which the dosing and / or shaping of a substance containing magnetizable particles is controlled in a magnetic field to provide a body corresponding to the desired body geometry. through shape-forming magnetic particles.

When making three-dimensional pieces from different materials individually or in small batches, mold costs often become the biggest cost factor. Single-piece sheet metal production is involved, for example, in the production of prototypes, molds and disposable products, which are therefore very expensive to manufacture by traditional methods, such as machining or modeling from sand (single-use molds).

In order to reduce mold costs, information technology has increasingly been used as a tool for mold design. Thus, systems are known in which machine tools are controlled numerically by means of a mold drawing in computer memory. Such so-called There are several CAD, CAM and CIM systems on the market. There will also be systems in which the dimensions of the body to be formed are obtained with electronic measuring devices.

However, these systems do not eliminate the most difficult problem of mold and template technology, i.e., the provision of the part itself, and due to the high cost of the systems, the overall cost may not be reduced.

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On the other hand, mold manufacturing methods based on layer technology are known, of which the so-called Laminated Object Manufacturing (LOM) is based on powder metallurgy. sintering. There, the mold is constructed according to planar cross-sections made from a graphic file created by the above-mentioned volume modeling program by adding a thin layer of sinterable powder at a time, which is selectively cured by laser beams so as to gradually form a three-dimensional body of the desired shape. This technique is new and the properties of a mold constructed in this way are thus difficult to assess, but it is known that the construction of a mold often takes days, which is a major improvement over current manufacturing times. In addition, it has been estimated that the cost of manufacturing the mold will be reduced by up to half and that the price of the system would be in the order of 1 MFIM.

The present invention corresponds in purpose to the LOM technique, but differs completely from it. In addition, it offers very significant advantages over LOM technology for the reasons set out below. The method according to the invention is characterized in that the shapes of the body to be manufactured are obtained by placing the forming members at a distance from each other in the mold so that the tips of the forming members are *: part of the surface to be formed or at a certain distance therefrom. . a magnetic flux such that the polarity of the magnetic flux of adjacent forming members is different, wherein the magnetic or magnetizable particle material in the mold space and / or added at this stage forms the appearance of the body to be formed by magnetic field lines passing from one forming member to another.

The most significant advantages of the invention are the manufacturing speed and its advantage, because expensive components such as lasers are not used in the formation of the mold or template. In addition, the magnetic material used, e.g., iron powder, can be used over and over again in various molds and templates because the cohesive force of the formed body is removed when the electromagnets are removed from the control. The rapid and automatic formation and disassembly of the mold, combined with the measurement of the shape data of the original by electronic methods, makes it possible in practice to build a duplicating machine for the part.

A preferred embodiment of the method according to the invention is characterized in that the magnetic field passing through the forming members is generated by electromagnets formed at one end thereof.

A further preferred embodiment of the method according to the invention is further characterized in that the mold formed according to the invention is kept in shape during casting by means of a magnetic field and, if desired, dismantled by removing the magnetic field. This technology greatly alleviates the problems of current casting techniques.

A preferred embodiment of the method according to the invention is characterized in that the shape of the body to be formed from the magnetizable particles is obtained by sintering or with a binder by means of heating and / or a chemical reaction, either singly or in layers. One special application of this is to leave the forming members inside the part, whereby they form part of the part to be manufactured.

Other preferred embodiments of the method according to the invention are characterized by what is stated in the claims below.

The device according to the invention is characterized in that the device consists of a surface in which elongate forming members extend through spaced holes in the surface, a magnet is formed at one end so that the polarity of the magnets of adjacent forming members is opposite, and that the forming member are movable longitudinally so that their tips are part of or at a certain distance from the surface to be formed, and at least part of the magnetic flux of the magnet can be passed through each forming member so that the material containing the magnetizable particles in the mold space and / or added at this stage using magnetic field lines in their desired shape during the process.

As can be seen from the above, the device according to the invention is cheap, simple and reliable. In addition, its control possibilities are versatile, in fact they range from manual adjustment of the forming members to the most sophisticated computer systems. Such a flexible possibility of use is particularly important, for example, in the manufacture of prototypes, and the device according to the invention can also be used as a design tool, with the aid of which plaster models of the final product can be made quickly.

A preferred embodiment of the device according to the invention is characterized by what is stated in the claims below.

The invention will now be described in more detail by way of example with reference to the accompanying drawings, in which

Figure 1 schematically shows the structure of a device according to the invention,

Figure 2 shows the formation of a mold surface in a device according to the invention,

Figure 3 shows a partial enlargement of the mold surface of Figure 2, 80620

Figure 4 schematically shows the magnetic polarities of the forming members in the device according to the invention,

Figure 1 shows schematically the main parts of the mechanical construction of the device according to the invention. The body, mold, template, or its surface is formed, as the case may be, by means of a planar or three-dimensional, for example completely closed, support surface. Figure 1 shows a part of the support surface 1 which is of non-magnetic material. The support surface can be shaped according to the part to be made, it can even be a ball surface. the support surface extending elongate forming means 2 which is fixed to the lower ends of the electromagnets 3. The polarity of the magnets are indicated by the letters S and N. All the forming means are movable in two directions expressly indicated by the arrow 4. The distance of the forming members can vary within wide limits depending on the size and complexity of the pieces to be made. In practice, the most common size class is 3 to 10 centimeters. A geometric surface produced by volume modeling is drawn flush with the tips of the forming members 2.

Figure 2 shows how the mold surface 5 is formed when the gaps between the forming members 2 are filled with a substance containing magnetic particles, in this example iron powder 6. A magnetic field is formed between the forming members, the field lines of which pass from one member to another. The powder is dispensed in the correct places and packed on the support surface 1. The dispensing is most preferably carried out automatically and in a controlled manner so that the correct amount of iron powder is always obtained at each point. Packaging, in turn, is performed at the time of dosing or separately. Between the forming members, the magnetic flux lines pass in the magnetizable material mainly according to the formed surface, forming a hard jacket surface 5 covering the entire mold rod area, which can be used directly as a mold or surface treated e.g.

On the other hand, in the case of the aforementioned part making, the forming members may be left in the part after sintering or the like, and may be utilized by shaping their ends to serve some special purpose otherwise difficult to achieve in the part, e.g., fastening members. This also means serial production with a view to the fact that the prefabricated "forming element matrices", i.e. blanks, can be mass-produced by conventional methods of engineering technology and made into pieces by the method according to the invention.

Figure 3 shows the mold surface in more detail between the mold bars. Here, for the sake of clarity, the drawn magnetized particles 7 (poles drawn in different patterns) are magnetically oriented in the direction of the field lines, which guarantees good cohesiveness and compression resistance of the mold. In this way, by selecting the particle size and shape, the mold result can also be significantly affected.

Figure 4 schematically shows the magnetic polarities of the forming members in the device according to the invention.

If necessary, the body or mold surface formed by means of the invention can be suitably treated in such a way as to improve its uniformity and / or strength by means of heat, fillers, a laser or the like.

The mold bars and their electromagnets can also be controlled by keeping some mold bars magnetically inactive or by changing their field strength and polarity relative to other bars 7 80620. The purpose of this type of control is to fine-tune the mold surface. Of course, the invention can also be implemented with permanent magnets, in which case the above-mentioned control possibilities are limited by the available magnets.

It will be clear to a person skilled in the art that the various embodiments of the invention are not limited to the examples given above, but that they may vary within the scope of the claims set out below. Thus, the magnetizable powder material may consist of any combination of materials in which para- or ferromagnetic materials or mixtures thereof are present.

Claims (10)

A method of making an article or mold, template or the like for an article in which the method of dosing and / or shaping a substance (6) contains non-magnetizable particles (7) is controlled in a magnetic field to produce a piece. corresponding to the geometric shape of the desired goods, such that the cohesive force is a magnetic field, whose field lines flow through the magnetic particles forming the desired shape (5), notable that the shape of the goods to be produced is achieved by in forming a molding member (2) at a distance from each other such that the tips of the forming member form part of the surface (5) to be formed or at a certain distance from it, and that it via the said molding means (2) leads to a magnetic flux such that the polarity of adjacent forming members is not present, wherein the magnetic space present and / or at this stage in or of the magnetizable particles (7) residing the blank (6) by means of which from one forming member to another running magnetic field lines form the outer mold (5) of the goods to be manufactured. 2. A method according to claim 1, characterized in that the magnetic field, which likes to be formed via the forming means (2) by means of electromagnets (3) arranged in one end thereof. 3. A method according to claim 1 or 2, characterized in that a formed mold is collapsed during the casting by means of magnetic field, and is then torn off by removing the magnetic field. 12 80620 4. A process according to any one of claims 1-3, characterized in that an iron-based powder is used as the magnetic substance or magnetizable particles (7). 5. A method as claimed in any one of claims 1-4, characterized in that the shaped surface (5) is surface-treated in a light manner with heat, fillers, laser and the like. to improve its smoothness and / or pour strength. 6. Preparation process according to claim 1, characterized in that the shape of a material formed of magnetizable particles (7) is achieved by sintering or with a binder by means of heating and / or a chemical reaction, either in a batch or one layer at a time. 7. A process according to claim 6, characterized in that the forming means (2) form part of the goods produced. 8. A method according to any one of claims 1-7, characterized in that the control of the forming means is carried out with a computer, such that the data supplied or formed in the computer over the shape of the goods or the form to be produced automatically controls the dosing and / or the movements of the forming means (7) to achieve the desired magnetic field field lines. Apparatus for realizing the method according to claim 1, wherein apparatus is provided with a surface corresponding to the shape of an object, or its shape, template or the like, or part thereof, characterized in that the device consists of a surface (1) having a spaced apart heel through which elongate forming members (2) extend, at one end of which is provided a magnet (3), so that the polarity of the adjacent forming members is opposite and the forming means are movable in their longitudinal direction, such that their tips form a part of the surface (5) to be formed or lie at a certain distance from it, it can be passed through at least a part of the magnetic flux of each of the forming means (2) so that the magnetisable particles (7) contained in the mold space and / or at this stage containing the magnetizable particles (7) brought to a certain shape are retained in the desired form during the process by means of the mold. e from one forming member (2) to another running magnetic field lines. 10. Apparatus according to claim 9, characterized in that the magnets (3) of the forming members are electromagnets.