JP2000317574A - Manufacture of structural element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a structural element obtained by cast molding at a small cost and at a constant speed by changing the posture of a positive pattern to manufacture a negative die by cast molding using a forming material in individual continuous process stages with respect to a reference plane. SOLUTION: A pattern 10 is turned by 180 deg. on the reference plane, for example, in the plane of a drawing, a forming material, for example, plaster materials 11a, 11b are filled to the upper end of inclined partial walls 10e and 10f, through an opening which is opening downwards and connection elements are preferably embedded in a soft plaster material so as to be projecting over a boundary surface into a cavity. In a second process in which the model 10 is turned by 180 deg. in the plane of the drawing, a new plaster material is filled from the above through the opening and filled in the whole cavity and then cured. No air is left behind in the cavity in this process. A negative mold for copying the structural element is obtained by removing the pattern 10 after the outer side is covered by the plaster.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method of manufacturing a structural element, preferably a prototype, in which a "die-cut" or positive model of the structural element is manufactured in a first step, Subsequently, the model is cast with a molding material to produce a mold, ie a negative mold, which then produces a structural element, preferably a prototype, by casting.

[0002]

BACKGROUND OF THE INVENTION A method of this kind is preferably, for example,
It is used for producing costly prototypes with complex cavities and is known from the state of the art. A plaster casting method in which the molding material is a gypsum material is such a method. In some applications, so-called "precision casting methods" are used instead of using plaster casting methods to produce such prototypes. A drawback common to these two methods is that both of these methods are difficult to produce prototypes with complex shapes and / or complex cavities.
Not at all suitable or those methods are very expensive.

[0003] A method for producing a structural element such as a prototype is known from DE 19545 167 Al. This method uses a polystyrene model, which is coated with a wax by dipping in a liquid wax. Next, ceramic sludge is applied to the surface of the wax. The model is then fired and the cavity formed by degassing the polystyrene is filled with a molding material using a precision casting method. In order to be able to produce more complex structural elements by this method, some parts of the structural element are first manufactured in this method, then the parts are immersed in wax, They need to be assembled into complex structural elements. This method is relatively cumbersome and therefore expensive because some components of the structural element have to be manufactured separately.

[0004]

Accordingly, an object of the present invention is a method for producing a structural element, and more particularly, a method for producing a prototype of the type specified above. Thus, it is an object of the present invention to provide a method by which structural elements can be manufactured with low technical costs, at a consistent speed and at a lower cost. A major problem with the conventional method is that when the cavities are filled with the molding material, the cavity cannot be completely escaped from the cavities, so that the complicated cavities cannot be duplicated by the molding material.

[0005]

SUMMARY OF THE INVENTION The present invention is a method of manufacturing a structural element, comprising: manufacturing a positive model of a structural element; casting the positive model with a molding material;
Producing a negative mold in a plurality of consecutive processing steps, and casting the mold to produce a structural element, wherein the position of the positive model with respect to a reference plane is It is a manufacturing method characterized by changing in each.

According to the invention, in at least one processing step, the molding compound is injected into the cavity of the model from above, and all the side openings of the model prevent the molding material from leaking out of the side openings. In order to do so, it is characterized by being plugged first.

Further, the present invention is characterized in that, in at least the second step of the continuous processing steps, an opening is provided at a place suitable for injection of the molding material for the model.

[0008] The present invention also relates to a method in which after each processing step, a model is placed on the model.
The method may further include rotating at a multiple of 90 ° about one of the three spatial axes.

The invention is also characterized in that in the processing step the connecting element is embedded in the molding material, and in the next processing step the adhesion of the new molding material to the already cured molding material is increased.

The invention is also characterized in that the connecting element has an undercut surface in order to obtain a reliable connection with the molding material.

[0011] The invention is also characterized in that the reinforcement is incorporated in the elongated cavity of the model, said cavity being filled with a molding material.

Further, according to the present invention, the reinforcing material may be a wire, a flat steel,
It is selected from the group consisting of round bars and metal parts.

Further, the present invention is characterized in that the molding material is a plaster material.

The invention is also characterized in that the structural element has a complex cavity and is made of aluminum.

The present invention is also a structural element manufactured by the above method.

An object of the present invention is a method for manufacturing a structural element, wherein a positive model of the structural element is manufactured in a first step, and a negative mold is manufactured by casting the positive model with a molding material. And a method for manufacturing a structural element, including making the structural element by casting the mold.

The model is cast with the molding material in several successive steps, and the placement or position of the model is changed with respect to the reference plane in each of the individual steps of casting or filling.

A major problem with the conventional methods is that when the cavities are filled with molding material, the complex cavities cannot be replicated by the molding material, since air cannot be completely escaped from these cavities. The present invention overcomes this problem as follows. In the steps of the first part of the method, the model is first cast with a molding material and the cavity is filled as much as possible with the molding material, wherein the model is placed in a first position with respect to a reference plane.
In the arrangement or position. In this first step, if there is an opening on the side of the model, the opening is closed so that the molding material does not leak out therefrom. The molding material is continuously injected from above through the opening. Next, the position of the model with respect to the reference plane is changed, for example, rotated by 90 ° about one of the axes of the model. The molding material is then refilled through the top opening of the model, and any side openings of the model are closed. Since the position of the model has been changed, air can be released from the portion of the cavity where air could not be released with the conventional model arrangement. Then, in another step of the method,
If necessary, reposition the model with respect to the reference plane and all side openings are closed. The molding compound is then refilled through the opening, which is now located at the top.

For example, if, after each step, the model is
If rotated in degrees and all three spatial axes are taken into account, the entire cavity of the model can be filled with molding compound. Depending on the structure of the model and the complexity of the cavity, up to six different arrangements of the model and correspondingly six steps are required to fill the model. Thus, the model can be completely duplicated.

Even when the method for casting a model with a molding material is divided into individual steps, the method defined by the present invention does not require the model to be divided, and must always be performed using an integrally molded model. It has the advantage that it can be done. Further, the method defined by the present invention can be performed smoothly and at a relatively consistent rate.

When a molding material such as plaster, which hardens and hardens relatively quickly, is used in the method according to the invention, the invention can be advantageous if a connecting element having a suitable geometry is used. These elements are cast together in a molding compound at each step of the method.
As the injected molding material in one step hardens and hardens when the next step starts, the adhesion of the new molding material to the already hardened molding material is enhanced by the connecting element. Preferably, a connecting element with an undercut surface is used, after the curing is completed, a secure connection of the individual surfaces of the molding compound is obtained. For example, readily available metal elements, such as screws, can be used as connecting elements, and there is no extra cost for the method.

If the model contains a defined cavity, for example a relatively long channel filled with molding material, after removing the model, the hardened part of the molding material, ie the relatively long Preferably, a stiffener is incorporated in the region of the molding material filling the channel, in order to prevent the filling channel of the arm from breaking or being damaged. Suitable elements, such as wires or other metal parts made of flat steel, round steel, etc., are used for such reinforcement.

In each step of casting a model with a molding material, the model is placed in a space position that is as advantageous as possible, and the number of steps of the casting method required according to the complexity of the cavity at that time is minimized. Is most preferred.

Still other benefits of the present invention are set forth in the following more detailed description.

[0025]

BRIEF DESCRIPTION OF THE DRAWINGS Other objects and features of the present invention will become apparent from the following detailed description in light of the accompanying drawings. However, the drawings are for explanation only, and do not limit the scope of the present invention.

In the drawings, like reference numbers refer to the same elements throughout the several views.

First, reference is made to FIG. This figure shows a model 10 for producing a prototype made of sintered polystyrene. In the drawing according to FIG. 1, a model 10 is shown schematically and in a very simplified manner to illustrate the method. The plaster material 11 is placed in the cavity of the model 10.
Is filled. When the method as defined by the present invention is used in real life, the model is
With respect to their geometry and their cavities, they are generally substantially more complex. However, the method as defined by the present invention is performed in the same way as described below.

The model 10 according to FIG. 1 comprises a bottom 10a, a vertical side wall 10b contacting the bottom 10a on the left, and a vertical side wall 10c contacting the bottom 10a on the right. The model 10 has a ceiling wall 10d, which extends parallel to the bottom 10a only partially with respect to the width of the model. With the left side wall 10b as a base point, the partial wall 10e extends downward at an acute angle inward in the cavity direction from the upper end. Inclined partial wall 1 made by molding
0f extends from the upper wall 10d to the right side wall 10c at an acute angle downward from the inner end of the upper wall 10d.

If the model 10 according to FIG. 1 is filled with plaster material 11 from above through the ceiling opening 13, the residual air will collect or be trapped in the left cavity 12 a and the right cavity 12 b, You cannot escape completely. This means that the cavity cannot be completely filled with plaster material 11 from above through opening 13.

In order to fill the cavity of the model 10 with the plaster material 11, the model 10 is placed at 180 ° on the plane of the drawing.
It was turned upside down, ie, to the position as shown in FIG. Only then can the cavity inside the model 10 be filled with plaster material 11, in such a way that the plaster materials 11 a, 11 b are opened through the opening 13, which then opens downwardly, via a hose, or It is first filled via a similar supply line. The plaster material 11a, 11b is filled only to the level at which the cavities 12a and 12b are filled, that is, only to the upper ends of the two inclined partial walls 10e and 10f, respectively. Therefore, plaster material 11a,
11b, two cavities 12 through the opening 13
a, 12b cannot leak downward again. Most of the cavity or cavity above it has not yet been filled with plaster material and will be filled in a subsequent second processing step.

The plaster materials 11a and 11b can harden and harden relatively quickly after the first processing step. The plaster material 11 to be filled in a second processing step may then be difficult to bond and adhere to the "hardened" or cured plaster material interface. For this reason, the connecting element 15 is used,
As shown in FIG. 2, the connecting elements 15 are embedded in a first injection step in a soft plaster material such that they protrude beyond the interface into the cavity. Then, in the next step, a new plaster material 11
Filling the remaining cavity space of the model 10 so that the new plaster material 11 is securely connected by the connecting element 15 and adheres well to the hardened plaster material 11a, 11b, as shown in FIG. Can be.

After the connecting element 15 is embedded in the plaster material 11a, the model 10 is again rotated by 180 ° on the plane of the drawing from the position shown in FIG.
Return to the initial position as shown in FIG. Cavities 12a, which were otherwise difficult to fill,
12b, as shown, already has plaster material 11a.
Contains. At this point, a new plaster material 11
It can be filled from above through the opening 13 and the model 1
All remaining cavities of zero can be filled with fresh plaster material. In this process, no air remains in the cavity of the model 10.

At present, plaster material 1 is inside the cavity.
The model 10 completely filled with 1, 11a, 11b is then placed in a container containing new plaster material to be further added, and then, as shown in FIG. Completely covered. After this treatment, the model 10 is completely replicated, both in its complex inner shape and in its outer shape, by the plaster material 11, 11a, 11b. The model 10 made of plastic, such as sintered polystyrene, can be removed by burning it or by other means. The result obtained is a negative plaster mold for producing a prototype to be produced. A metal, such as aluminum, is continuously injected into the mold and the structural element is duplicated such that the shape of the structural element corresponds to the model 10. Hardened plaster material 11, 11 surrounding the outside of the structural element and, of course, in the cavity of the structural element
a, 11b, 11c are mechanically removed.

The connecting element 15 is shown enlarged in FIG. As coupling element 15, it is also possible to use a screw with a nut or any other, preferably element with an undercut surface. As can be seen from the drawing, the shaft 15a of the connecting element 15 is partially embedded in the already solidified plaster material 11a. However, one part of the shaft 15a, such as the nut 16, is
It initially projects into an unfilled cavity. The head 15b has an undercut surface 15c on its lower side. The anchor-shaped screw head 15b is the undercut surface 15.
As a result of having c and due to the shape of the nut 16, after the new plaster has been filled, a good adhesion of the new plaster material 11 to the solidified plaster material 11a is obtained. The shape of the connecting element 15 is rather randomly selected in the illustrated embodiment according to FIG. These connecting elements may have heads in the form of bevels, grooves, serrations, teeth or the like.

Another embodiment of the present invention is shown in FIGS. FIG. 5 shows a schematic simplified view of another model 20, which is filled in several steps according to the method as defined by the present invention. The model 20 has a plurality of cavities, which are arranged so that the model cannot be completely filled in one processing step. Therefore, the following procedure is used. At the position shown in FIG. 5, the model 20 is first filled with the plaster material 11a in the cavity shown at the top.
Here too, the connecting element 15 can be inserted into the plaster material 11a in order to enhance the adhesion to the additional plaster material that is filled in the subsequent processing steps. As can be seen from FIG. 5, the lower cavity 12b
Initially remain unfilled. The model 20 is now rotated 180 ° in the plane of the drawing and moved to the position shown in FIG. The cavity filled with plaster material 11a is located at the bottom at present. The cavity 12b, which is currently located at the top, is then filled with plaster material 11b in the next step, to the state shown in FIG. The connection element 15 is again embedded in the plaster material 11b in order to facilitate the adhesion to the additional plaster material.

Next, reference is made to FIG. Based on the drawing according to FIG. 6, the model 20 is turned 90 degrees clockwise on the plane of the drawing.
° rotated and then added further plaster 1
1c is placed in the container 21. Plaster material 11
After curing of c, the model 20 can be removed, for example, by burning it,
A plaster mold having a cavity corresponding to the shape of the previous model 20 is obtained. Here, too, the metal is injected in a plaster form and the structural elements are obtained in a shape conforming to one of the models 20. Again, plaster materials 11a, 11b, 11
c can be removed mechanically.

Thus, while only certain embodiments of the invention have been illustrated and described, it will be obvious that many changes and modifications can be made without departing from the spirit and scope of the invention.

[0038]

Even when the method for casting a model from a molding material is divided into individual steps, the method defined by the present invention does not require the model to be divided and always uses an integrally molded model. It has the advantage that it can be carried out. Further, the method defined by the present invention comprises:
It can be done smoothly and at relatively consistent speed.

When a molding material such as plaster, which hardens and hardens relatively quickly, is used in the method according to the invention, the invention can be advantageous if a connecting element having a suitable geometry is used. These elements are cast together in a molding compound at each step of the method.
As the injected molding material in one step hardens and hardens when the next step starts, the adhesion of the new molding material to the already hardened molding material is enhanced by the connecting element. Preferably, a connecting element with an undercut surface is used, after the curing is completed, a secure connection of the individual surfaces of the molding compound is obtained. For example, readily available metal elements, such as screws, can be used as connecting elements, and there is no extra cost for the method.

[Brief description of the drawings]

FIG. 1 is a simplified schematic sectional view of a model filled with plaster material according to the method defined by the present invention.

FIG. 2 is a corresponding simplified schematic diagram of the model of FIG. 1 shown in a clockwise rotated 90 ° arrangement.

FIG. 3 is an enlarged detail showing the cutout III from FIG. 2 in a further position.

FIG. 4 is another simplified schematic diagram of the completed mold resulting from the model of FIG.

FIG. 5 is a simplified schematic cross-sectional view of a model filled according to a method defined by the present invention, according to an alternative embodiment.

FIG. 6 is another view obtained by rotating the model shown in FIG. 5 by 180 °.

FIG. 7 is another view of the model according to FIGS. 5 and 6, shown at another stage of the method defined according to the invention.

[Explanation of symbols]

 10, 20 model 10a bottom 10b, 10c vertical side wall 10d ceiling wall 10e, 10f partial wall 11, 11a, 11b, 11c plaster material 12a, 12b cavity 13 ceiling opening 15 connecting element 15a axis 15b head 15c undercut surface 16 Nut 21 container

 ──────────────────────────────────────────────────の Continued on the front page (71) Applicant 599064410 Bienhorster Weg 19 46395 Bocholt GERMAN Y (72) Inventor Christian Grunewald Germany 46395 Bocholt Bimenholster Werk 19A F-term (reference) 4E093 FB05 FC01 FC10 GB12

Claims (11)

[Claims] 1. A method of manufacturing a structural element, comprising: manufacturing a positive model of the structural element; casting the positive model with a molding material; and manufacturing a negative mold in a plurality of successive processing steps. And casting the mold to produce a structural element, wherein the position of the positive model relative to a reference plane changes in each of the successive processing steps. 2. In at least one processing step, the molding compound is injected into the cavity of the model from above, and all side openings of the model are formed to prevent molding material from leaking out of said side openings. 2. The method according to claim 1, wherein the plugging is performed first. 3. The method according to claim 1, wherein at least a second of the successive processing steps is performed.
2. The method according to claim 1, wherein an opening is provided at a location suitable for injecting the molding material of the model. 4. The method of claim 1, further comprising, after each processing step, rotating the model about one of the three spatial axes at a multiple of 90 °. 5. The method according to claim 1, further comprising the step of embedding the connecting element in the molding compound in a processing step and increasing the adhesion of the new molding compound to the already cured molding compound in the next processing step. 6. The method according to claim 5, wherein the connecting element has an undercut surface in order to obtain a secure connection with the molding compound. 7. The method of claim 1, wherein a stiffener is incorporated into the elongated cavity of the model, the cavity being filled with a molding material. 8. The method of claim 7, wherein the stiffener is selected from the group consisting of a wire, a flat bar, a round bar, and a metal part. 9. The method according to claim 1, wherein the molding material is a plaster material. 10. The method according to claim 1, wherein the structural element has a complex cavity and is made of aluminum. 11. A structural element manufactured by the method according to claim 1.