JPH09308942A - Manufacture of mask for forming mold laminated layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically execute the arrangement of a support in a mask. SOLUTION: Three-dimensional data of a blank are inputted into a treating part 22 through an inputting device 20. The treating part 22 slices the three- dimensional data of the blank into two-dimensional cross sectional shapes to obtain the mask shape in each layer. Then, a support-making part 22c automatically generates the support in the diagonal direction at 45 deg. angle to an island part from the surroundings and the part is added. Further, the support added to a simple space in the inner part is recognized as a one connecting the same outline and rejected. In such a method, the support can automatically be set.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a mold laminating mask used for forming each layer of a casting mold formed by laminating.

[0002]

2. Description of the Related Art Since a casting is made by pouring molten metal into a mold, generally when making a casting, first of all, a reverse mold of the casting is made. The mold is mainly a mold and a sand mold (hereinafter referred to as a sand mold) because of its material.
It is divided into The mold is durable, but expensive
It is often used when many identical products are manufactured (mass production). On the other hand, the sand mold is used for production of a relatively small amount such as a prototype (prototype), or when there is a complicated shape or internal shape. That is, the sand mold is inexpensive, and since the sand mold is broken and the product is taken out after casting, it is not necessary for the casting to come out of the sand mold as it is, and a casting having a complicated shape can be produced. Further, a casting having an internal shape can also be created by using a mold called an sand core for creating an internal shape.

Conventionally, when a sand mold is prepared, an inverted mold (mainly wood, resin, metal) is first prepared by NC (numerical control) processing or the like, and sand is poured into the sand mold to solidify the sand mold. Was being modeled. However, in this sand mold manufacturing method, the draft must be taken into consideration when designing the reverse mold of the sand mold. Especially, the inverted type of sand type is usually 2
Since it is necessary to divide, it is necessary to design a parting plane (parting plane) where to divide, and to design a draft according to each drafting direction of the two divisions. Therefore, much time is required for designing the mold and designing the mold.

Further, since the NC cutter path is created based on the shape of the mold and the mold is cut out, the calculation of the cutter path also becomes the calculation of the three-dimensional shape, and the calculation becomes enormous. was there. Further, there are many problems such as mold division and gradient shape calculation that are left to the designer's judgment, and there is a problem that it is difficult to reflect the design change because the three-dimensional shape model cannot be unified.

Here, it is not a good idea to spend a great deal of time in creating a prototype. Therefore, a rapid prototyping method for directly modeling a prototype from three-dimensional CAD (computer-aided design) data has been proposed. This rapid prototyping is 3
One-dimensional object is considered to be a stack of two-dimensional cross-sectional shapes with a fine plate thickness of about 0.2 mm, this cross-sectional shape is shaped, and by stacking this, a two-dimensional object is shaped Is.

For example, in USP 4,247,508,
A method for rapid prototyping, which utilizes a laser beam, is shown. That is, a thin layer of heat-melting plastic particles or the like is formed, and the portion to be solidified of this layer is scanned with a laser beam to melt and solidify the beam-irradiated portion to form a two-dimensional structure. Then, this operation is repeated to form a three-dimensional object. According to this method, a prototype can be directly formed.

Further, this conventional example describes that an inverted mold is directly produced, and a sand molded article is obtained by using plastic-coated sand. There is also a suggestion to use a mask when scanning a laser beam.

According to this method, since a molded article can be obtained directly, it is not necessary to consider the above-mentioned parting and draft. Therefore, sand molds of various shapes can be formed relatively easily from the CAD data of the modeled object.

The above-mentioned conventional example is basically for forming a prototype, and no consideration is given to mass production. That is, when a single two-dimensional structure is formed, a considerable amount of time is required because the laser beam scans all the portions to be solidified. Therefore, it is not realistic to manufacture a large number of sand molds for mass production using this conventional technique.

On the other hand, when the sand mold is formed by rapid prototyping, it is not necessary to consider the cut-off and draft when creating the sand mold. For this reason, there is no useless part in the sand mold, and unnecessary casting burrs in the cast product can be eliminated. Therefore, it is considered that if the post-treatment of the casting can be made more efficient and the sand mold can be made efficiently, this can be utilized to achieve efficient mass production of the casting.

[Related Art] Therefore, the applicant of the present invention, in Japanese Patent Application No. 7-290932, has a sand mold laminating method suitable for mass production, which enables solidification of a two-dimensional cross-sectional shape at high speed by using a mask. Proposed. According to this method
Since one mask is used, a predetermined range of one sectional shape can be solidified at high speed. And 1 corresponding to casting
A mask for the two-dimensional cross-sectional shape of the set is manufactured in advance,
By repeatedly using this mask, the sand mold can be repeatedly manufactured, and the mass sand mold for casting can be efficiently manufactured. The solidification method is not limited to laser irradiation, and a liquid binder windmill or the like can be applied.

[0012]

However, in the related art described above, when the mask is manufactured, the mask needs an island portion corresponding to the sand core and separated from the surroundings. In this case, a support is needed to hold the island portion on the mask. This support cannot be obtained by calculation of the two-dimensional cross-sectional shape by slicing the cross-sectional shape of the casting, and must be designed separately. Therefore, conventionally, the designer has determined the existence of the island portion and designed the support.

It is an object of the present invention to provide a method of manufacturing a mask which can also automatically set this support.

[0014]

SUMMARY OF THE INVENTION The present invention is a method for producing a mold laminating mask for use in forming each layer of a casting mold formed by laminating, wherein
A mask shape creation process that creates a mask shape based on the three-dimensional cross-sectional shape, an island part detection process that detects an island part surrounded by a space from the created mask shape, and based on parallel lines at predetermined intervals It has a support placement step of placing supports at predetermined intervals in the space surrounding the detected islands, and a step of creating a mask based on the mask shape after support placement, and the supports are automatically placed in the mask shape. The feature is that a mask is manufactured.

As described above, in the present invention, the supports are arranged in parallel lines at a predetermined interval. Therefore, this support arrangement can be easily automated. It should be noted that the support interval of the parallel lines may be set to an interval that can sufficiently support the island portion. Further, if a support parallel to the contour of the island portion is provided, the two will be integrated when they come into contact with each other.
On the other hand, the normal island is expressed in the XY coordinate system, and X
Many are parallel to the axis and Y axis. Therefore, in this XY coordinate, an oblique direction based on the 45 ° direction is preferable.

Further, the present invention is a method for producing a mold laminating mask used when forming each layer of a casting mold to be laminated, wherein the mask is based on the two-dimensional cross-sectional shape of the casting. A mask shape creating process that creates a shape, an island detecting process that detects islands surrounded by spaces in the created mask shape, and a space surrounding the islands that are detected based on a grid with a predetermined interval. And a step of forming a mask based on the mask shape after the support is arranged. The support is automatically arranged in the mask shape to manufacture the mask.

By thus forming the support in a lattice shape, it can be easily and automatically arranged. Further, the strength of the support can be made sufficient by disposing the support at predetermined intervals.

Further, the present invention is a method for producing a mold laminating mask used for forming each layer of a casting mold to be laminated, which is based on a two-dimensional cross-sectional shape of a casting shape. A mask shape creation process that creates a shape, an island detection process that detects islands surrounded by spaces in the created mask shape, and the placement of supports to support the islands according to prescribed rules. It is characterized by including a support position automatic setting step of automatically determining the position and a position changing step of changing the automatically set support according to the connection state between the island portion and the support.

After automatically arranging the support in this way, the position of the support is changed according to its connection state.
For example, you can remove unnecessary supports that are simply placed inside the frame shape, add supports for islands that are not supported by the support at regular intervals, or change the position of the support that supports only the ends of the islands. The processing to do is performed automatically. As a result, the optimized placement of the support in the mask shape can be achieved by automatic placement.

Another aspect of the present invention is characterized in that, in the above-mentioned automatic setting step, the arrangement position of the support is made different between masks used for adjacent layers.

If the positions of the supports in the adjacent layers are the same, the space of the mold formed by the supports is continuous and a part of the casting is formed there. By changing the position of the support between adjacent layers, the space of the mold caused by the support can be made a predetermined one, it is possible to prevent hot water (molten metal) from entering here, and to make the shape of the casting different Can be prevented.

Another aspect of the invention is characterized in that, in the automatic setting step, the positions of the supports are made different between the masks used for at least three adjacent layers.

For example, in the case of using a lattice-shaped support, if the support patterns are simply different between the two layers, a common portion will be formed and this will become a space for casting. By making the three layers different, the common part of the two layers does not continue to the third layer, and the problem as described above can be avoided.

Another aspect of the present invention is characterized in that, in the automatic setting step, the island portion is determined by the closed contour, and the support for connecting the same contours is eliminated as unnecessary.

This makes it possible to eliminate an unnecessary support for simply connecting the inside of the donut-shaped island portion.

According to another invention, in the optimum changing step, the stability of the island portion is judged from the center position of the island portion and the connection position of the support to the island portion, and according to this stability,
It is characterized by changing the connection state of the support.

If only the ends of the island are supported by the support, the island becomes unstable. Therefore, the support can be changed to the center of the island to make the mask stable.

Further, another invention is characterized in that the method further comprises a step of producing a mask by subjecting a sheet metal to laser processing based on a mask shape in which a support is set.

By forming a mask by laser processing a sheet metal such as an iron plate, a predetermined mask shape can be easily realized.

Then, using the mask thus prepared, a predetermined range of sand in each layer is solidified, and this is repeated to form a sand mold. Furthermore, by casting a casting using the sand mold created,
The casting can be easily manufactured based on the dimensional rough material shape data.

In particular, according to this manufacturing method, the data from the three-dimensional data of the rough material to the formation of the casting can be centralized and held, and the design change can be easily dealt with. Further, since the sand molds are formed in layers, the data handled for forming the sand molds are basically two-dimensional shape data, which facilitates data processing. Furthermore, there is no need to consider drafts, cut-offs, etc. when forming the sand mold, and the effect of facilitating its manufacture is also obtained.

As described above, according to the present invention, it is possible to efficiently form a mask, a sand mold and a casting.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention (hereinafter referred to as embodiments) will be described below with reference to the drawings.

The overall procedure of the "entire processing" processing will be described with reference to FIG. First, a casting scale for correcting the shrinkage allowance generated when a casting is made is added to the three-dimensional shape of a product (coarse material) manufactured by casting, and the three-dimensional shape of the rough material is corrected. That is, since the casting is manufactured at a high temperature, the three-dimensional shape of the rough material at room temperature is corrected to the shape desired at the time of high temperature manufacturing. This correction process is automatically performed by the casting rule function of the conventional three-dimensional solid modeling system. At this time, the warp correction is also taken into consideration.

Next, based on the corrected three-dimensional shape of the rough material, a sand outer shape required for casting the rough material is designed by a three-dimensional system. This design needs to ensure a certain thickness or more from the shape of the rough material, and can be easily designed (modeling the sand mold shape). At this time, the sanding allowance of the sand mold is considered.

Next, the corrected rough material shape is arranged on the designed sand outer shape. Here, the reverse shape of the rough material shape is the sand shape, and the reverse shape of the sand shape is the mask shape. Therefore, the mask shape is equal to the rough material shape, and the processing can be performed simply by arranging the rough material shape as it is.

Since the mask shape is formed in this manner, the formed mask shape is sliced in accordance with the sand stacking pitch of 0.1 to 0.3 mm to obtain a plurality of two-dimensional data (two-dimensional cross-section data). To get

A mask is prepared by using the two-dimensional data created in this way, but the mask shape obtained here may have an island shape corresponding to the sand core. This island shape has a space around it, and it will fall off as it is. Therefore, it is necessary to support the island shape. In this embodiment, this support is automatically created, which will be described later.

By such processing, the mask shape is determined, the shape data of the outer edge of the mask shape is automatically extracted, and this shape data is automatically converted into the NC code. Then, the iron plate is laser-processed based on the NC code to create a mask.

A sand mold is manufactured using the mask thus obtained, and a product is cast using the sand mold.

The conventional casting mold (sand mold) is manufactured by
Even if the three-dimensional shape already exists, it was necessary to design the draft and the parting due to the mold division when forming the core mold for forming the outer mold and the hollow shape. So we needed very complicated 3D modeling. In addition, it was impossible to have a three-dimensional shape in a centralized manner, and when the design was modified, the design had to be redone.

According to this embodiment, the mold for producing the intermediate sand mold limits the laser irradiation light to only the necessary portion.
It becomes an iron plate mask with a three-dimensional cross section. So, the core shape,
No need for sloped shape, parting, etc. Therefore, the mask shape for hardening the sand mold is a shape obtained by simply applying a casting rule to the shape of the rough material to be created, and can be created by a very simple process. Further, since the rough material shape and the mask shape are linked, the three-dimensional shape can be easily unified and the design change can be easily dealt with.

"Support Shape Automatic Generation Algorithm" When the support shape is appropriately arranged, it becomes a degassing shape at the time of casting, and it is preferable that it exists.
However, if the arrangement is not appropriate, the shape of the rough material to be cast will be impaired. Further, if the support shape is too large, the contour to be cut increases during mask processing, the laser processing / cutting takes too much time, and the cost for mask formation increases.

Therefore, the following is a condition for creating a support.

(I) Do not impair the shape of the rough material (ii) Sufficient mask strength (iii) Keep to the minimum necessary number (iv) Function effectively as a vent hole.

Therefore, in this embodiment, as shown in FIG. 2, the support shape is created by the following steps.

First, an island shape is extracted from the mask shape by a predetermined algorithm, and a support generated by a predetermined rule is automatically placed in a space surrounding the island shape.

This automatically generated support is generated under a fixed condition and is not necessarily optimally arranged. Therefore, the automatic optimization process performs an automatic optimization process such as a rearrangement for the support of a predetermined condition. I do.

In this way, the support is automatically optimized, but finally the designer can manually confirm and correct it. In some cases, it may be necessary to assist or add support under special conditions, and this can be done manually.

In this way, the support can be efficiently added to generate the mask shape. In particular, since the mask shape can be basically automatically generated, the burden on the designer is greatly reduced. Further, since the support can be automatically generated from the two-dimensional cross-sectional shape obtained from the three-dimensional shape of the rough material that is unified, it is possible to easily perform the correction accompanying the design change.

"Automatic Support Shape Creation Process" If the support comes into contact with the rough material shape, the shape is impaired. That is, when the support comes into contact with the rough material shape, both are integrated at that portion, and the rough material shape at that portion is impaired. On the other hand, an ordinary rough material has many contours in the x and y directions. Therefore, the pattern of the support is a slanted parallel line which always has a direction of 45 ° in the design coordinate system of the rough material shape. By doing so, it is possible to prevent the support from coming into contact with the end portion of the rough material and increasing the width of the rough material. If the cross section of the support is independent, hot water does not enter here and functions as a gas vent hole, but there is no adverse effect on the rough material shape.

For example, if the island shape in the rough material shape is rectangular, as shown in FIG. 3, the support is automatically generated in the direction of 45 °, and only the space portion is extracted as the support.

The direction of 45 ° may not be preferable depending on the rough material, and this value is used as a parameter so that an arbitrary value can be input. Further, the spacing (pitch) of the supports can be changed.

Here, if the masks of the respective layers have the same support arrangement, the supports are continuous and the shape here becomes a casting as it is. Therefore, it is necessary to change (shift) the support shape of each layer.

For example, in the case of a unidirectional pattern as shown in FIG. 4, by shifting the pattern setting in each layer,
It is possible to prevent the same pattern from continuing. In the figure, the pattern shown by the solid line is the pattern of the layer, and the pattern shown by the dotted line is the pattern of the adjacent layer. According to this method, two patterns may be alternately used,
Generating a pattern is much easier. However, with this method, the strength of the entire mask may be insufficient when the island portion and the space portion are large.

Therefore, when the shape of the island portion, the space portion or the like is large, it is preferable to form the pattern in a grid pattern. When two grid patterns are prepared and used alternately, as shown in FIG. 5, a common portion is formed, which becomes a casting. Therefore, as shown in FIG. 6, three different patterns (three patterns of a, b, and c in this case) are prepared, and these are used in order such as a → b → c → a → ... Good. This can prevent the common part from occurring. In FIG. 6, the pattern a is shown by a solid line, the pattern b is shown by a dotted line, and the pattern c is shown by a dashed line.

<Determination of Pattern> The method of arranging such a support varies depending on the shape of the part to be cast and the like. Therefore, it is preferable that the arrangement pattern of the supports in each layer can be variously changed. In this embodiment, the arrangement of the supports can be determined by the parameter instructions described below.

(I) Set Number of Support Patterns N This parameter N determines how many kinds of support patterns are used. In the above example, 2 or 3 is selected.

(Ii) Mask Repeat Setting M This parameter M sets how many times the same pattern is used repeatedly. With this, it is possible to set how many supports at the same position continue, and to control the size of the gas vent hole.

The parameters N and M are shown in FIG.
As described above, the M sheets have the first shape, the next M sheets have the second shape, and up to the N shape is used.

(Iii) Inclination G This G is set to 45 ° by default, but can be changed to any value.

(IV) Pitch As shown in FIG. 8, pitch 1 (pitch 1) indicates the pitch of the support in the −45 ° direction, and pitch 2 (pitch 2) indicates the pitch of the support in the 45 ° direction. Note that p
By setting the values of ich1 and ich2 to 0, the support in that direction is not arranged. Further, although the inclination is changed by the above-mentioned inclination G, since the supports in the two directions are always orthogonal to each other, G = 60, and if pic1 is −60 °, pic2 is 30 °.

(V) Support Width W The support width W determines the support width.

By determining the parameters in this way, the first support pattern is, as shown in FIG. 9, for the −direction support, p from the lower left point.
Supports are sequentially arranged on ich1. Also, regarding the support in the + direction, the support is arranged in order from the lower right point by pich2. Then, in the second pattern, the support is pitch1 / N or pitch2 / N at the lower left end,
Move closer to the bottom right point. Therefore, in the Nth pattern, as shown in FIG. 10, the − direction support is located at the position pich1 / N from the lower left end point, and the + direction support is located at the position pich2 / N from the lower right end point. Become.

"Support Arrangement Optimization Processing" Effective arrangement cannot be achieved simply by arranging the support with the above parameters. Therefore, it is necessary to delete unnecessary parts and additionally create necessary parts. Therefore,
In this embodiment, automatic optimization processing is prepared.
Also, in the normal case, such processing enables effective placement, but if there are special conditions, this may need to be changed. Therefore, the designer is allowed to confirm and correct the contents.

<Automatic Optimization Processing> (i) Automatic Deletion of Unnecessary Parts When the supports are automatically arranged as described above, if there is a space inside, the supports will always be arranged. Therefore,
Needless support needs to be removed. In the case of the mask shape as shown in FIG. 11, arranging the supports in the direction of 45 ° causes unnecessary portions for connecting the same shapes. The white parts in the figure are unnecessary parts, and the black parts are necessary parts.

Therefore, as shown in FIG. 12, first, an oblique cross section of the linear support shape portion is used to obtain the original cross section (mask).
The shape portion is subtracted to divide into divided areas. And
In order to distinguish whether each divided area is necessary or not, a flag indicating which loop (the outline of each cross-sectional shape is recognized as a loop) with which the divided area is divided is attached. It should be noted that the loops are sequentially numbered from the left outer side to the contour of each cross-sectional shape. In addition, the outer contour of the shape is a left-handed loop, and the inner contour is a right-handed loop.

As a result, the support at the upper left of FIG. 11 is unnecessary because all four intersections are formed with the loop 2. Further, the support provided only between the loop 4 and the loop 7 is unnecessary. Thus, if all four intersections are formed with the same loop, it can be determined that this support is unnecessary. So check the value of the flag,
Determine if support is needed or not.

When there are five or more intersection points for one support, the support passes through the edge of the shape as shown in FIG. Such support is not desirable, so
Consider unnecessary.

(Ii) Automatic Addition of Supports Supports are arranged uniformly for each set pitch. Therefore, the island part that did not hit the support remains unsupported. Therefore, it is necessary to arrange a support for such an island portion.

Therefore, first, the pairs of left and right loops are sequentially checked, and the pairs having no intersection with the support are extracted. Here, in the non-perforated shape, there is no corresponding right loop. Further, if there are a plurality of distant holes in one shape, there will be a plurality of right loops in one left loop. Such loops are also included in the above pair.

By such processing, it is understood that the island portions in the shape of the left side portion of FIG. 14 are extracted, and these island portions need the support shown by the broken line.

By this check, a min-max box is created for the extracted pair. That is, as shown in FIG. 15, a quadrangle surrounding the island is created. Then, a 45 ° support shape that passes through the center of this quadrangle is created.

Further, the cross-sectional shape is difference-calculated from the support shape thus obtained to divide the area, and at the same time, a flag indicating which loop has collided is added to the intersection.

Next, only the extracted pair of flags having a counterclockwise loop flag is taken out, and this is used as a required support shape, and the obtained supports are summed to obtain the required support as shown in FIG. Get the shape.

At the stage where only the counterclockwise loop flag is extracted, the support inside the U-shaped island portion as shown in FIG. 17 is also selected. Therefore, if all the intersection points are counterclockwise loops, this is not adopted.

(Iv) Detection of unstable portion and reinforcement of support Even in the island portion to which the support is connected, there are unstable island portions depending on the connection position of the support. For example, as shown in FIG. 18, if a support is connected to only one end of the elongated island portion, the support of the island portion is unstable.

The support in this case is shown in FIG. In this way, first, a min-max box is created. In addition, each of the created min-max boxes is formed with a slightly smaller small box, and the four sides formed by the two boxes are zones 1 to 4, respectively.

Then, it is determined which zone the intersection with the support belongs to, and when all of them belong to the same zone, it is determined that the support for the island portion is unstable.
The overlapping portion of each zone may be either one of the overlapping portions.

In this way, when it is determined that the island is an unstable island portion, the island portion is subjected to min-m in the same manner as described above.
Automatically add support through the center of the ax box. Note that the same applies to the processing for the island portion on the U-shape.

(V) Double check with adjacent pattern at the time of support addition / reinforcement When the support is added / reinforced as described above, a support different from the original support pattern is completed. Therefore, it is necessary that this support does not overlap with the support of the adjacent layer.

Therefore, as shown in FIG. 20, in the X'Y 'coordinate system in which the XY coordinates are rotated by 45 °, the positions of the past two support center lines are stored.

Then, when a new support is added, it is checked whether or not it overlaps with the stored adjacent support.

For example, as shown in FIG. 21, it is determined whether there is support stored within the support range,
If there is, the position of the support is the support width + α
The process of shifting in the + or − direction by (for example, 1 to 2 mm) is repeated until there is no overlap. This makes it possible to shift the positions of the supports whose positions overlap with those of the adjacent support.

<Support Shape Confirmation / Manual Correction Function> As a result of the above-described automatic optimization processing, an almost optimum support shape is completed. However, it is preferable to be able to confirm this and manually correct it if necessary. For this reason, the present embodiment has a confirmation / manual correction function.

(I) Mask shape confirmation function (ordering function) First, the mask shapes can be displayed one by one. Then, as shown in FIG. 22, this is sequentially displayed by backward and forward feed. This allows the designer to sequentially check the mask. At the time of display, a display (current number / total number) of the number of masks being displayed is displayed.

(Number-of-sheets designated display function) The number of sheets is designated and the corresponding mask is displayed. By doing this, when checking, the shape that needs correction is searched for, and if found,
Later, the shape can be specified and corrected.

(Corrected Mask Shape Confirmation Function) When the correction work is completed by the mask shape correction function, which will be described later, if the correction work is performed, the mask shape is recalculated and displayed after completion. Therefore, the corrected mask shape can be confirmed.

(Ii) Support shape correction function (support shape removal function) A support point is surrounded by a locate point in order to remove any support. That is, FIG.
As shown in FIG. 3, the locating point surrounds a predetermined area and removes the support located therein. In this case, the seven locate points 1 to 7 define a substantially circular range.

This processing is performed by sequentially inputting locate points while displaying an arbitrary mask shape as described above. Then, after the predetermined range is designated, the designated support is removed by instructing the removal. In addition, specify one support at a time,
It may be possible to remove the designated support. These instructions are preferably given by clicking with a mouse.

(Support Shape Addition Function) This is a function to add support to an arbitrary space portion. For example, as shown in FIG. 24, by specifying locate points 1 to 4, the range surrounded by these is set as the support. In this case, the difference calculation with the mask-shaped portion is automatically performed. Note that the support of the set width may be added by designating two points.

[Overall System Configuration] FIG. 25 shows the overall configuration of a system for manufacturing a casting product. As described above, the system includes the computer 10 and the laser processing machine 1.
2. It comprises a sand mold manufacturing device 14 and a casting machine 16.

The computer 10 obtains as many mask shapes as necessary to obtain this rough material shape from the rough material three-dimensional shape. The laser processing machine 12 processes the iron plate based on the obtained mask shape to obtain a corresponding mask. The sand mold manufacturing apparatus 14 uses the obtained mask to irradiate a predetermined portion of the plastic-coated sand with laser light to obtain a sand mold shape for one layer, which is sequentially laminated and repeated to obtain a sand mold.
The obtained sand mold is supplied to the casting machine 16, and the metal (hot water) melted therein is poured into the sand mold. Then, after cooling and solidification, the sand mold is removed, and a cast product is obtained.

[Mask Shape Creation] Computer 1
0 is for generating a mask shape, and includes an input device 20, a processing unit 22, and an output device 24, as shown in the functional block of FIG. Further, the processing unit 22 includes a casting ruler / warp correction unit 22a, a two-dimensional cross section forming unit 22b, and a support creating unit 22c.

The input device 20 receives the rough material three-dimensional shape data, and also receives the input of the above-mentioned parameters and manual operation instructions. Further, the output device 24 is
The obtained mask shape is output as data. The output device 24 may include display, print output, and the like.

Then, the processing unit 22, as described above,
Casting, warp correction processing, formation of two-dimensional cross-section data, creation of supports, etc. are performed.

[Mask Processing] As shown in FIG. 27, the laser processing apparatus 12 first takes in mask shape data and processes the masks one by one based on the taken-in data. That is, the mask portion of the iron plate is irradiated with laser to cut the iron plate. Then, data for each mask is sequentially taken in and sequentially processed to create one set (one sand mold) of masks.

[Manufacturing of sand mold / casting] Sand mold manufacturing apparatus 14
Is composed of a sand laminating device for laminating sand by one layer, a mask setting mechanism for sequentially setting a mask here, and a laser irradiation device for irradiating each layer of sand with a laser.

Then, as shown in FIG. 28, first, one layer of sand is placed on the sand laminating apparatus (S11). This sand is a plastic-coated sand having a predetermined diameter, which is coated with a thermosetting plastic or the like. Next, a mask is set above the sand (S12). When the mask can be set, the laser is irradiated from above the mask (S
13). As a result, the sand below the opening of the mask is irradiated with laser light, and the sand in this part solidifies (integrates).
I do.

Next, it is judged whether the mask is completed (whether there is a next mask) (S14). If there is a next mask, S11 is executed.
Return to the next sand layer. Then, if it is finished in S14, the process is finished. In this way, the sand mold is manufactured.

Finally, a casting is produced using the sand mold thus produced (S15).

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a procedure for manufacturing a mask.

FIG. 2 is a flowchart showing a procedure for creating a support shape.

FIG. 3 is a diagram showing a configuration of a diagonal support shape.

FIG. 4 is a diagram showing a configuration when two types of diagonal support patterns are used.

FIG. 5 is a diagram showing a configuration in which two types of lattice-shaped support patterns are used.

FIG. 6 is a diagram showing a configuration when three types of lattice-shaped support patterns are used.

FIG. 7 is a diagram illustrating a mask repeat setting number M and a support pattern N.

FIG. 8 is a diagram illustrating a pitch and a width of a support.

FIG. 9 is a diagram showing an arrangement of supports in a first pattern.

FIG. 10 is a diagram showing an arrangement of supports of an Nth pattern.

FIG. 11 is a diagram illustrating a support unnecessary portion.

FIG. 12 is a diagram illustrating division of supports.

FIG. 13 is a diagram illustrating an example of unnecessary support.

FIG. 14 is a diagram showing a place where support needs to be added.

FIG. 15 is a diagram showing a situation (part) of adding a support.

FIG. 16 is a diagram showing a situation (overall) of support addition.

FIG. 17 is an explanatory diagram of a support for a U-shaped island portion.

FIG. 18 is an explanatory diagram of an unstable island portion.

FIG. 19 is an explanatory diagram of determination of an unstable island portion.

FIG. 20 is an explanatory diagram of storage of a support position.

FIG. 21 is a flowchart showing a procedure of a double check with an adjacent pattern of a support.

FIG. 22 is a diagram illustrating a function of turning over the display of mask shapes.

FIG. 23 is a diagram illustrating a support shape removing function.

FIG. 24 is a diagram illustrating an additional function of a support shape.

FIG. 25 is a diagram showing an overall configuration of a system.

FIG. 26 is a diagram illustrating the functions of a computer.

FIG. 27 is a diagram showing a laser processing process.

FIG. 28 is a diagram illustrating a process from sand mold production to casting.

[Explanation of symbols]

10 computer, 12 laser processing machine, 14 sand mold manufacturing apparatus, 16 casting machine, 20 input device, 22 processing unit, 24 output device.

Front page continuation (72) Inventor Katsura Ogura 1 Toyota-cho, Toyota-shi, Aichi Toyota Motor Co., Ltd.

Claims (8)

[Claims] 1. A method for producing a mask for forming a mold stack, which is used when forming each layer of a casting mold formed by stacking, wherein a mask shape is formed based on a two-dimensional cross-sectional shape of a casting shape. The mask shape creation process to create, the island part detection process to detect the island part surrounded by the space part from the created mask shape, and the space part surrounding the island part detected based on the parallel lines at a predetermined interval. A mold characterized by having a support arranging step of arranging the supports at predetermined intervals, and a step of forming a mask based on the mask shape after the support arranging, and manufacturing the mask by automatically arranging the supports in the mask shape. Manufacturing method of forming mask. 2. A method for producing a mold laminating mask used when forming each layer of a casting mold to be laminated, wherein a mask shape is created based on a two-dimensional cross-sectional shape of a casting shape. Mask shape creation process, island part detection process that detects island parts surrounded by spaces in the created mask shape, and support is placed in the space part that surrounds the island parts that are detected based on a grid with a predetermined interval And a step of forming a mask based on the mask shape after the support is arranged, and a mask is formed by automatically arranging the supports in the mask shape to manufacture a mask for forming a mold. . 3. A method for producing a mold laminating mask used for forming each layer of a casting mold to be laminated, wherein a mask shape is created based on a two-dimensional cross-sectional shape of a casting shape. The mask shape creation process, the island detection process that detects the islands surrounded by the space from the created mask shape, and the placement position of the support to support the islands is automatically performed according to the specified rules. The method for manufacturing a mask for forming a mold stack, comprising: a support position automatic setting step determined in step 1) and a position changing step of changing the automatically set support according to a connection state between the island portion and the support. 4. The mold stack according to claim 1, wherein in the automatic setting step, a support arrangement position is different between masks used for adjacent layers. Manufacturing method of forming mask. 5. The mold according to claim 1, wherein in the automatic setting step, a support arrangement position is made different between masks used for at least three adjacent layers. Method of manufacturing a mask for forming a laminate. 6. The method according to any one of claims 1 to 5, wherein in the automatic setting step, the closed contour is used to determine the island portion, and the support for connecting the same contours is unnecessary. A method for manufacturing a mask for forming a mold stack, which is characterized in that the mask is removed. 7. The method according to claim 1, wherein in the optimum changing step, stability of the island portion is judged from a central position of the island portion and a connection position of the support to the island portion. ,
A method for manufacturing a mask for forming a mold stack, characterized in that the connection state of the support is changed according to this stability. 8. The method according to claim 1, further comprising the step of subjecting a sheet metal to laser processing based on a mask shape in which a support is set to manufacture a mask. And the mask making method.