JP2006167900A - Molding method of mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a molding method of a mold capable of molding a part to be a cutting blade even when it is of a cutting type at a sharp angle without forming a tool passage data of an extension surface for over-run working and molding a part not to be the cutting blade without outline working and run-on working. <P>SOLUTION: This is the molding method of the mold to mold in the cutting type having a specified borderline R and a shape surface M by cutting a casting flap (t) of the workpiece W cast and molded for the cutting type having the part 1 to be the cutting blade and the part 4 not to be the cutting blade by operating a tool C in accordance with a previously set tool passage, it discriminates the part 1 to be the cutting blade and the part 4 not to be the cutting blade from each other, the part 1 to be the cutting blade has a shape corresponding to an outline Ca of the tool C on an outer part of the borderline R and forms an extension surface E to extend the shape surface M in an area where an edge part 1a of the cutting blade holds a sharp angle, and the part 4 not to be the cutting blade forms a non-interfering surface K with which the panel 5 does not interfere in correspondence with the outline Ca of the tool C. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a mold forming method for finishing a cast mold material (hereinafter referred to as a workpiece) by machining.

  For example, a press die or the like performs surface processing and contour processing on a cast work using a tool such as a ball end mill, and removes a casting allowance to finish a die having a predetermined contour line and shape surface.

  In the surface machining and contour machining, tool path data is created based on mold shape data, and the control unit controls the operation of the tool based on the tool path data and performs cutting. The surface processing is performed while shifting the tool by one pitch in the surface direction according to a processing method (scan processing or the like) according to the shape of the region to be processed. The contour machining is performed by offsetting the tool outside the contour line of the mold and moving the tool according to the tool path data.

Such a mold forming method is also disclosed in Patent Document 1 below. Here, if one of surface machining and contour machining is performed first and the other is performed later, not only will the data creation man-hour increase in creating the tool path data, but damage to the tool and reduction in cutting speed will occur during machining. Therefore, a method of performing a cornering process for processing a casting allowance outside the processing region has been proposed before these processes. In this way, the machining area for surface machining and contour machining can be clarified, the machining process and machining area can be reduced in surface machining, and the creation of tool path data can be facilitated. It is said that cutting can be facilitated.
JP 2000-11037 A (summary, claim 1, paragraph numbers [0019] to [0021], see FIG. 1)

  However, although this machining method gives good results with respect to the machining after chamfering, the chamfering itself produces a corner with a large machining allowance, so the load on the tool is high. The feed rate will also decrease.

  In addition, when the mold is to be molded later, it is necessary that the panel does not hit the mold and does not cause interference, so contour processing must be performed over the entire circumference of the mold even if there are unnecessary portions. There is also a problem that must be done. In particular, the press mold includes not only a so-called draw type but also a cutting type for cutting a panel. In the case of a cutting die, the portion that becomes the cutting edge must be formed so as to have a sharp angle, and the portion that does not become the cutting edge may be preferably formed without performing contour processing. However, in the squaring process that requires the entire circumference contour machining, there is a problem that the contour machining has to be performed to an unnecessary portion.

  Furthermore, when a ball end mill is used as a tool and the tool path is parallel to the contour line and the tool is moved by one pitch and machining is performed, uncut material is left between a certain path and the adjacent path, and this amount is large. There is a risk that the load will increase in the subsequent finishing process. In the case of performing the above-mentioned squaring process in advance, the final position is already machined, so the uncut residue generated between the last machined part formed at a predetermined feed pitch is not constant, and finishing machining is performed. The load on the tool at the time may increase. In addition, if the feed pitch is reduced in order to reduce the amount of uncut material, there is a problem that the moving distance of the tool becomes longer.

  There are also the following problems with the cutting mold. Since the edge of the cutting die must be sharply formed, the tool path needs to be overrun without terminating at the end of the die. Even in the case of overrun, the tool path data must be created with a surface instead of a line, and tool path data for an extended surface obtained by extending the tool path data of the shape surface of the mold is created.

  When such an extended surface is created, not only the movement distance of the tool itself is increased, but also the creation of the tool path data takes time.

  In addition, if the part that does not become the cutting edge of the cutting die is not subjected to contour processing and is left as cast molding, when the panel is molded later, if the panel does not interfere with the mold, the problem is However, in the case of interference, it is necessary to perform a so-called chasing process to remove the interfering portion and form a non-interfering surface. The tool path data for the follow-up process is not to create a simple extension surface, but is troublesome and increases the number of steps for creation.

  Here, in this specification, the extended surface is formed as a casting allowance in order to make the portion that becomes the cutting edge a sharp angle, and the non-interfering surface is the shape of the mold when the panel is molded. It is formed so as not to cause interference.

  The present invention has been made in order to solve the problems associated with the above-described prior art, and a portion that becomes a cutting edge even if it is a cutting die can be used without creating tool path data of an extended surface for overrun processing. It is an object of the present invention to provide a mold forming method capable of forming at a sharp angle and forming a portion that does not become a cutting edge without the need for contour processing or follow-up processing.

  The present invention that achieves such an object is to operate a tool based on a preset tool path by using a casting cost of a workpiece cast for a cutting die having a portion that becomes a cutting edge and a portion that does not become a cutting edge. A mold forming method for forming into a cutting mold having a predetermined contour line and a shape surface, wherein the part that becomes the cutting edge and the part that does not become the cutting edge are determined, and the part that becomes the cutting edge is Forming an extended surface that extends the shape surface outside the contour line and has a shape corresponding to the contour of the tool and the edge portion of the cutting edge maintains a sharp angle; The part that does not become a cutting edge is a mold forming method characterized by forming a non-interfering surface having a shape corresponding to the contour of the tool and in which the panel does not interfere with the mold.

  According to the first aspect of the present invention, the portion that becomes the cutting edge forms an extended surface outside the contour line in a range that corresponds to the contour of the tool and that the edge portion of the cutting edge maintains a sharp angle. The non-interfering part forms a non-interfering surface that does not interfere with the panel and has a shape that corresponds to the contour of the tool. Can be formed at a sharp angle without forming the edge, and the portion that does not become a cutting edge can be formed without the need for contouring or driving-in.

  According to the invention of claim 2, since the extended surface and the non-interfering surface are surfaces having the same shape as the contour shape of the tool, the speed and ease of processing are improved, and the creation of tool path data is facilitated.

  According to the invention of claim 3, since the extended surface and the non-interference surface are formed in a state where the edge of the contour line and the contour line of the tool are in contact with each other, the portion that becomes the cutting edge can be easily formed with a sharp edge portion, A portion that does not become a cutting edge easily forms a non-interference surface on which the panel does not interfere.

  According to the invention of claim 4, if the extension surface is formed within one pitch from the last feed pitch in the contour line and is formed in a state where the edge of the contour line and the contour line of the tool are in contact with each other, a short extension is achieved. Surfaces can be easily formed, tool path data can be easily created, and this is extremely advantageous in terms of manufacturing cost.

  According to the invention of claim 5, the non-interference surface is formed by the tool position where the distance from the edge position of the contour line to the tool is set by the feed pitch, and the tool position is set by the panel shape and the casting allowance. , It is easy to form a non-interfering surface that does not interfere with the panel because it is formed at the larger tool position.

  According to the sixth aspect of the present invention, the non-interference surface is formed by setting the position where the center of the tool is located on the contour line as the tool position. Therefore, if the position of the contour line is clear, the non-interference does not interfere with the panel. It becomes easy to form a surface.

  According to the invention of claim 7, since the tool movement characteristics of the machine used are considered in setting the tool path data, the tool can be reached at an accurate position even when the casting allowance is cut, resulting in a cutting edge. The part can be easily finished to have an edge part having a sharp angle.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<First Embodiment>
FIG. 1 is a schematic perspective view showing a molding state of a mold according to the present invention, FIG. 2 shows an embodiment of a mold molding method according to the present invention, a sectional view taken along line 2-2 in FIG. FIG. 3 is an enlarged view of a main part of FIG. 2.

  In FIG. 1, the present embodiment is a method for forming a cutting die having a portion 1 that becomes a cutting edge and a portion 4 that does not become a cutting edge. In this forming, the tool C is controlled on the basis of tool path data set by a control unit (not shown), and as shown in FIG. 2, the casting allowance t of the cast workpiece W is cut to obtain a predetermined contour. The line R and the shape surface M are obtained.

  For example, in order to form the shape surface M by surface machining, as shown in FIG. 1, a tool C such as a ball end mill is used, and this is cut on the upper surface Wa of the workpiece W by feeding it by 1 pitch P. To do. Further, in order to form a predetermined contour line R (indicated by a broken line) by contour machining, a tool C such as a ball end mill or a square end mill is used, and this is applied to the outer peripheral surface Wb of the workpiece W and cut. In the invention, the contour processing is partial. Finally, a finishing process is performed to remove uncut parts and the like to finish a predetermined mold.

  The portion 1 that becomes the cutting blade is later built up by welding to form a blade portion, but it is necessary to form the edge portion 1a at a sharp angle. Specifically, as shown in FIG. 3, the angle α formed by the molded shape surface M and the surface 2 orthogonal to the outer shape surface formed by the contour R is 20 degrees or less, more preferably, The sharp angle should be 15 degrees or less.

  Moreover, since the part 4 which does not become a cutting edge is a part which shape | molds a panel in a predetermined shape, it is necessary not to raise | generate interference with a panel.

  Therefore, in this embodiment, when the end portion of the workpiece W is formed, the portion 1 that becomes the cutting edge has a shape corresponding to the contour Ca of the tool C outside the contour line R, and the edge of the cutting blade. The extended surface E that extends the shape surface M within the range in which the portion 1a maintains a sharp angle is formed, and the portion 4 that does not become a cutting edge corresponds to the contour Ca of the tool C, and the panel 5 interferes. The tool C is operated to cut the casting allowance t of the cast workpiece W so as to form a non-interfering surface K that does not. For this reason, the tool path data set in advance for operating the tool C is different between the portion 1 that becomes the cutting edge and the portion 4 that does not become the cutting edge.

  Hereinafter, a method for acquiring tool path data will be described with reference to the flowchart shown in FIG.

  (1) The tool movement characteristic of the machine to be used is examined (S1).

  First, when obtaining tool path data, it is preferable to examine the tool movement characteristics of the machine to be used. In general, the process of cutting the casting allowance t by subjecting the workpiece W to surface machining or contour machining is heavy cutting, and in this processing machine, the tool C tends to move inward from the movement path. Therefore, it is preferable to set such characteristics in the tool path data in advance, so that the tool C can reach a predetermined position through an accurate movement path and can be processed more accurately and accurately.

  In order to examine the tool movement characteristics of the machine, the workpiece W is cut with a tool and the degree of inward tendency is measured. As a result, even when the casting allowance t is cut, the tool C can be reached at an accurate position, the moving distance at which the portion 1 that becomes the cutting edge can be a sharp angle can be determined from the cutting amount of the tool C, and the edge It becomes easy to finish the portion 1a to have a sharp angle without so-called sagging. In addition, since this characteristic changes with each used machines, it is necessary to carry out with each used machine.

  (2) It is determined whether the part 1 is a cutting edge or the part 4 is not a cutting edge (S2).

  Next, in the part 1 which becomes a cutting edge and the part 4 which does not become a cutting edge, there is a difference whether an extended surface E is formed or a non-interference surface K is formed, and tool path data is also different. Therefore, it is necessary to determine whether the part 1 is a cutting edge or the part 4 is not a cutting edge. This determination may be performed before the extended surface E and the non-interfering surface K are formed, and may be performed after the process of determining the position of the next tool C. In any case, this determination can be easily determined based on the cutting-type design drawing.

  If such a determination is made, regarding the portion 4 that does not become a cutting edge, a portion that does not require contour processing to be performed later is found, which simplifies the processing and is advantageous in terms of manufacturing cost.

  (3) Formation of an extended surface at a portion that becomes a cutting edge and determination of a tool position (S3).

  When a cut is made in the casting allowance t and the shape surface M is reached, the tool C now forms an extended surface E in the portion 1 that becomes the cutting edge, and does not appear in the portion 4 that does not become the cutting edge, which will be described in detail later. Although the interference surface K is formed, it is preferable that both the extended surface E and the non-interference surface K are as short as possible in view of the creation of the tool path data.

  Therefore, in the present embodiment, as shown in FIG. 2, with respect to the extension surface E, an extension having a shape corresponding to the contour Ca of the tool C is provided outside the contour line R in order to minimize overrun of the tool C. The surface E is formed only in the range corresponding to one pitch of the feed pitch P. In this way, the extended surface E to be formed becomes a short extended surface E as shown in FIG. 4, and can be formed without unnecessarily overrunning the tool C. As a result, the tool path data is not unnecessarily obtained, the moving distance of the tool C can be shortened, and unnecessary machining is eliminated. In addition, as shown in FIG. 2, the machining range may be such that a small tool path having a pitch of 1 pitch is formed on the outer side from the contour line R, and the creation of the tool path data for the extended surface E is extremely simple.

  Further, the extended surface E has a shape as formed by the tool C, that is, a surface having the same shape as the contour shape of the tool C. In this way, unnecessary processing does not have to be performed, the processing cost is further reduced, and it becomes practical.

  However, even if the extended surface E is in a range corresponding to one pitch, the position of the tool C that forms the extended surface E is a problem. Therefore, in the present embodiment, the tool position where the extended surface E is formed is such that the machining range is outside the contour line R within one pitch of the feed pitch P and the end of the contour line R, as shown in FIG. And the outline Ca of the tool C are in contact with each other.

  In this way, with respect to the amount of uncut material, the amount of uncut material generated between the final cutting site of the tool within the contour R and the cutting site within one pitch outside the contour R (see FIG. 2). Even if the hatched portion a) is maximized, it does not become larger than the normal uncut amount, and the load does not increase in the subsequent finishing.

  In addition, since the contour line Ca of the tool C is in contact with the end of the contour line R of the mold, the edge portion 1a after molding is secured, and when the contour processing is performed later, a sharp angle necessary for cutting can be obtained.

  (4) Formation of a non-interference surface at a portion that does not become a cutting edge (S5).

  As for the portion 4 that does not become a cutting edge, the panel 5 can be smoothly formed when it is processed using the completed cutting die, and is formed on the minimum non-interfering surface K that does not interfere with the die. For example, when the shape of the panel 5 when processed with the completed cutting die is the shape shown by the solid line in FIG. 5, if the arc-shaped non-interference surface K corresponding to the contour Ca of the tool C is formed, the interference is caused. There is no problem.

  Therefore, the portion 4 that does not become the cutting edge is determined from the panel shape or the molded shape that is processed by the completed die, and as shown in FIG. The range which becomes the minimum distance without causing interference is obtained, and the tool C is cut to form a non-interference surface K corresponding to the contour Ca of the tool C.

  The non-interference surface K formed by the tool C is a surface having the same shape as the contour shape of the tool C as shown in FIG. 6, and the tool position is defined by the contour line Ca of the tool C as shown in FIG. This is a state in contact with the end of the line R. Thus, if it is the same shape as the shape of the tool C, unnecessary processing does not need to be performed, the processing cost is further reduced, and it is practically preferable. In addition, if the tool position is in contact with the end of the contour line R, the contour line R can be accurately formed.

  In view of the above points, in this embodiment, both the extended surface E and the non-interference surface K have a shape corresponding to the contour Ca of the tool C, and the end of the contour R and the contour Ca of the tool C are It will be formed in contact.

  (5) Selection of determination criteria for the tool position forming the non-interference surface K (S4).

  However, the tool position when forming the non-interference surface K is based on the feed pitch (hereinafter referred to as A for convenience) and on the basis of the shape determined by the panel shape or the like (hereinafter referred to as convenient). In the case of B).

  In the case of A, the non-interfering surface K is formed by processing a range of one pitch p from the last feed pitch P in the contour line R. On the other hand, the case of B is a case where the non-interference surface K is formed from a panel shape when the panel is formed later and a shape determined by the casting allowance t to be cut.

  For example, as shown in FIG. 7, a non-interfering surface K is formed in the case of A when the panel shape or the molded shape processed with the completed mold protrudes substantially linearly as in the panel 5 indicated by the solid line. Even in the case of B, even if the non-interference surface K is formed, any of them does not cause interference. However, in the case where A does not cause interference, the case of A is safer than the case of B. In other words, regarding the distance L from the position of the contour line R to the tool position, when A (La) and B (Lb) are compared, La> Lb, and the larger case may be selected. It will be.

  In addition, as shown in FIG. 8, when the panel shape or molded shape processed with the completed mold protrudes downward as in the case of the panel 5 indicated by the solid line, a non-interference surface K is formed in the case of A. Then, interference occurs, but in the case of B, no interference occurs. Therefore, the case of B is preferable. Also in this case, the distance L from the position of the contour line R to the tool position is Lb> La, and the case of B is larger than the case of A.

  Accordingly, as a reference for forming the non-interference surface K, the distance L from the position of the contour line R to the tool position is compared between A (La) and B (Lb), and the larger one is selected. It will be good.

  (6) The position of the tool axis is adjusted (S6).

  Even if the position of the tool C is determined, accurate machining cannot be performed unless the tool axis supporting the tool C is set at a predetermined position. Therefore, it is necessary to adjust the position of the tool axis. In addition, the state of the tool C shown in FIG. 1 is illustrated, and is not necessarily processed in the illustrated state.

  In the present embodiment, the shapes obtained from the respective cross sections of the press die that is a finished product are connected, and the bending and the retrograde portion of the tool movement path are set to values in the Z-axis direction of the tool axis for contour machining (see FIG. 1). Arrange on the lower side.

  (7) A machining range within the feed pitch is created outside the contour line (S7).

  When the state of the tool is determined, a range in which the tool moves and is processed is determined. The machining range is within one feed pitch P outside the contour line R.

  (8) A path of the surface machining tool is created using the shape (S8).

  When the tool state and machining range data are determined, the path data of the surface machining tool is created from the shape of the press die that is the finished product.

  When the tool path data is determined in this way, it is input to the control unit and actual machining is performed.

Second Embodiment
FIG. 9 is a schematic cross-sectional view showing a state in which the non-interference surface K according to the second embodiment of the present invention is formed. In addition, the same code | symbol is attached | subjected to the member which is common in the member shown to FIGS. 1-8, and description is abbreviate | omitted.

  In the first embodiment, either the case where the feed pitch is used as a reference or the case where the shape determined by the panel shape or the like is used as a reference for determining the tool position forming the non-interference surface K is selected. If the contour machining range can be specified and the shape characteristic of the panel 5 is also known as an arc shape as shown in the figure, for example, the center position of the tool C is set as the position of the contour line R, and the contour shape of the tool is not. The interference surface K may be formed.

  As shown in FIG. 9, for example, if the contour processing range is clearer than the contour line R, the position where the contour line Ca of the tool C contacts the contour line R, that is, the center O of the tool C is on the contour line R. The position at which the tool C is located may be the position of the tool C, and the non-interference surface K having a surface having the same shape as the contour shape of the tool C may be formed.

  In this way, it is possible to form a non-interfering surface K that does not cause interference, and to form the non-interfering surface K with a minimum distance, which is more than the case of the first embodiment. The decision is easy.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims. For example, in the above embodiment, the present invention is applied to a press mold, but it is needless to say that the present invention can be applied to other molds.

  The present invention is a mold forming method suitable for processing when a press mold is formed from a casting mold.

It is a schematic perspective view which shows the shaping | molding state of the type | mold which concerns on this invention. FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1, showing an embodiment of a mold forming method according to the present invention. FIG. 3 is an enlarged view of a main part of FIG. 2. It is sectional drawing which shows an extended surface. It is sectional drawing which shows the shaping | molding state of a non-interference surface. It is sectional drawing which shows a non-interference surface. It is sectional drawing which shows the reference | standard which forms a non-interference surface. It is sectional drawing which shows the reference | standard which forms a non-interference surface. It is sectional drawing which shows the reference | standard which forms a non-interference surface. It is a flowchart which shows the acquisition method of tool path data.

Explanation of symbols

2 ... the part that becomes the cutting edge,
5 ... The part that does not become a cutting edge,
Ca: Tool outline,
E ... Extension surface,
K ... non-interference surface,
M: Shape surface,
O ... the center of the tool,
P ... feed pitch,
R ... contour line
t ... Casting fee W ... Workpiece.

Claims (7)

A casting cost of a workpiece cast and formed for a cutting die having a portion that becomes a cutting edge and a portion that does not become a cutting edge is cut by operating a tool based on a preset tool path, and a predetermined contour line. A mold forming method for forming into a cutting mold having a shape surface,
The portion that becomes the cutting edge and the portion that does not become the cutting edge are discriminated, and the portion that becomes the cutting edge has a shape corresponding to the contour of the tool outside the contour line, and the edge of the cutting blade Forms an extended surface that extends the shape surface within a range where the portion maintains a sharp angle, and the portion that does not become the cutting edge forms a non-interfering surface that corresponds to the contour of the tool and does not interfere with the mold of the panel A mold forming method characterized by:   The mold forming method according to claim 1, wherein the extension surface and the non-interference surface are surfaces having the same shape as the contour shape of the tool.   3. The mold forming method according to claim 1, wherein the extension surface and the non-interference surface are formed in a state in which an end portion of the contour line is in contact with a contour line of the tool.   4. The mold forming method according to claim 1, wherein the extended surface is formed within one pitch from the last feed pitch in the contour line.   The non-interfering surface is larger when the distance from the edge position of the contour line to the tool is compared with the tool position set by the feed pitch and the tool position set by the panel shape and casting allowance. The mold forming method according to any one of claims 1 to 3, wherein the mold is formed at one of the tool positions.   The said non-interference surface forms the position where the center of a tool is located on a contour line as a tool position, The shaping | molding method of the type | mold in any one of Claims 1-3 characterized by the above-mentioned.   The mold forming method according to claim 1, wherein the tool path data is set in advance in consideration of a tool movement characteristic of a machine used.

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