JP2009146000A - Production device, production method and production program for machining data - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a production device, a production method and a production program for machining data of a working machine, preventing occurrence of variation of a gear shape. <P>SOLUTION: Coordinates of a plurality of coordinate points P1(X1, X2), P2(X2, Y2), P3(X3, Y3), etc. positioned on an outer shape track L of a gear are calculated in an xy coordinates passing the origin O1 (α1=0, β1=0), and an arc s1 (a radius r1) of a central angle 10° with the origin O1 as the center, passing the first coordinate point P1 and the second coordinate point P2 is calculated. A line segment g connecting the second coordinate point P2 and the third coordinate point P3 is calculated, an intersection point O2 between a perpendicular bisector m and a radial line h1 of the arc s1 is calculated, an arc s2 with the intersection point O2 as the center with a distance from the intersection point to the second coordinate point P2 as a radius r2 is calculated, and end parts of the arcs s1, s2 cross their radial lines h1, h2 at right angles wherein the arc s2 is approximate data of the gear outer shape track from the second coordinate point P2 to the third coordinate point P3. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a machining data creation device, a creation method, and a creation program for a processing machine that performs predetermined machining on a workpiece.

There are already various methods for manufacturing gears. For example, conventionally, there is a method of forming a gear shape on a workpiece (such as a gear base material or a gear mold) by electric discharge machining. . This processing machine (wire electric discharge machine) applies a high voltage between the wire electrode and the workpiece while applying tension to the thin wire electrode while facing the workpiece, so that the wire electrodes An electrical discharge is generated between the workpiece and the workpiece. And a wire electric discharge machine can form a gear by moving a wire electrode along the above-mentioned gear shape with respect to a work piece (for example, refer to patent documents 1).
JP-A-8-25500

  When forming a gear by wire electric discharge machining as in the above prior art, when predetermined machining data is input to the wire electric discharge machine, the wire electric discharge machine moves the wire along the gear shape based on the machining data. To drive. At this time, the wire electric discharge machine needs to drive (relatively) the wire in a positional relationship in which the wire is offset from the outer shape of the gear by the wire diameter + discharge gap.

  In this case, the wire electric discharge machine may be driven by simply sliding the wire in parallel with the offset for the linear portion of the outer shape of the gear acquired as the processing data. However, regarding the curved portion of the outer shape of the gear, when the wire electric discharge machine slides in parallel as described above and drives the wire, a part of the shape becomes uncertain. That is, for example, when a curve is approximated by a plurality of partial arcs, the wire electric discharge machine is undefined as to which of the arc centers should be driven by taking the offset amount into account at the joint between the arcs. It becomes. Since the above prior art does not consider this indefiniteness, the shape of the manufactured gear may vary.

  The same problem may occur in a die-sinking electric discharge machine or a milling machine using electrodes.

  An object of the present invention is to provide a machining data creation device, a creation method, and a creation program for a processing machine that can prevent the occurrence of variations in gear shape.

  In order to achieve the above object, the first invention provides a display means for displaying data for processing a gear shape on a gear base material or a gear manufacturing die, and a condition for defining the gear shape. Based on the condition data input by the input means for inputting data and the condition data, two partial arcs that share the same tangent line and are connected to each other at the contact point to the tangent line are used successively and continuously. Data generating means for generating approximate data of the external locus and output means for outputting a gear shape based on the approximate data generated by the data generating means to the display means.

  In the machining data creation device of the first invention of this application, when the operator inputs the condition data by the input means, the data creation means creates approximate data of the outer shape locus of the gear shape using the partial arc. Then, the output means outputs the gear shape to the display means, whereby the operator can confirm the data contents to be processed. The processing machine (wire electric discharge machine, die-sinking electric discharge machine, milling machine such as end mill, etc.) that has received this processing data uses the gear data for the gear base material (or mold) based on the processing data. Form.

  Here, for example, in the case of wire electric discharge machining, it is necessary to drive (relatively) the wire in a positional relationship in which the wire is offset by the wire diameter + discharge gap with respect to the outer shape of the gear. The same offset drive is required also in the die-sinking electric discharge machine and milling machine using the above-mentioned electrode.

  Corresponding to this, the data creation means of the first invention of this application approximates the gear outline locus so that the partial arcs share the same tangent line (in other words, the tangent lines are the same) when the approximate data is created. As a result, the data creating means forms the gear contour locus so that the end portions (butt end portions) of these two partial arcs are always perpendicular to the respective radial lines. Thus, the processing machine can reliably form the gear outline by driving (relatively) the wire or the like in a positional relationship in which the two partial arcs are simply shifted in the radial direction by the offset. Therefore, the processing machine can prevent the occurrence of variations in gear shape.

  According to a second invention, in the first invention, the data creating means includes a plurality of coordinate points that are located in the outer shape locus of the gear shape and sequentially include a first coordinate point, a second coordinate point, and a third coordinate point. Coordinate calculating means for calculating, a first partial arc passing through the first coordinate point and the second coordinate point, and a second partial arc passing through the second coordinate point and the third coordinate point; The approximate data from the first coordinate point to the third coordinate point is created by connecting the coordinate points so that they are tangent to each other.

  The end of the first partial arc that passes through the first second coordinate point and the end of the second partial arc that passes through the second third coordinate point are respectively the radial lines (first partial arcs) at the second coordinate point. And the radius of the second partial arc). Thereby, when processing a 1st partial circular arc, a processing machine should just drive a wire (relatively) in the position for 1st partial circular arc radius + offset from the center point of the 1st partial circular arc. When machining the second partial arc, the second partial arc radius + the same offset from the center of the second partial arc and the second partial arc radius + the same offset from the center of the second partial arc. The wire may be driven (relatively) at this position. In this way, the processing machine can reliably form the outer shape of the gear.

  According to a third aspect of the present invention based on the second aspect of the present invention, the data creating means includes a straight line connecting the center point of the first partial arc and the second coordinate point, and a line connecting the second coordinate point and the third coordinate point. 1st center determination means which determines the intersection with the perpendicular bisector of a minute as the center point of the said 2nd partial circular arc is provided.

  The first center determining means takes the intersection of the straight line passing through the second coordinate point and the perpendicular bisector of the second coordinate point and the third coordinate point, and sets this as the center point of the second partial arc. Thereby, the second partial arc that passes through the second coordinate and the third coordinate and is perpendicular to the radial line in the second coordinate can be realized.

  In a fourth aspect based on the third aspect, the first center determining means is a radius calculating means for calculating a straight straight line connecting the center point of the first partial arc and the second coordinate point; A perpendicular bisector calculating means for calculating the vertical bisector of the line connecting the coordinate point and the third coordinate point; and an intersection calculating means for calculating an intersection of the radial straight line and the vertical bisector It is characterized by providing.

  When calculating the center point of the second partial arc, the radius calculating means calculates a radial straight line connecting the first partial arc and the second coordinate point. On the other hand, the vertical bisector calculating means calculates a vertical bisector connecting the second and third coordinate points. Then, the intersection point calculation means calculates the intersection point between the radial straight line and the perpendicular bisector. In this manner, the first center determining means of the machining data creation device of the fourth invention of the present application can calculate the center point of the second partial arc.

  In a fifth aspect based on the fourth aspect, the vertical bisector calculation means includes a line segment calculation means for calculating a line segment connecting the second coordinate point and the third coordinate point; A midpoint calculating means for calculating a point, and a straight line passing through the midpoint and orthogonal to the line segment is calculated as the perpendicular bisector.

  In a sixth aspect based on any one of the third to fifth aspects, the data creation means is centered on the center point determined by the first center determination means, and from the center point to the second coordinate point. Arc data creation means is provided which uses the second partial arc whose radius is a distance as the approximate data from the second coordinate point to the third coordinate point.

  When the arc data creating means creates the second partial arc, approximate data from the second coordinate point to the third coordinate point can be created.

  According to a seventh aspect of the present invention, in any one of the second to sixth aspects, the data creation unit includes a calculation standard for creating data of the partial arcs that are sequentially used based on the condition data input by the input unit. Reference arc setting means for setting a reference partial arc is provided.

  The data creation means can create the second partial arc using the reference partial arc set by the reference arc setting means as a calculation reference and using this as the first partial arc. Thereafter, the data creating means can create a new second partial arc by the same calculation, with the second partial arc as a new first partial arc. The data creation means can create approximate data of the outer shape locus of the gear shape by sequentially repeating such calculations.

  In an eighth aspect based on the seventh aspect, the reference arc setting means passes the start coordinate point used at the start of data creation among the plurality of coordinate points and the first coordinate point corresponding to the start coordinate point. The second center determining means for determining the center point of the reference partial arc and the radius determining means for determining the radius of the reference partial arc.

  When setting the reference arc, the second center determining means determines the center point of the reference partial arc, and the radius determining means determines the radius of the reference partial arc. Thereby, the reference arc setting means can set the reference partial arc from the start coordinate point to the first coordinate point.

  A ninth invention is characterized in that, in the eighth invention, the radius determining means sets the radius of the reference partial arc so that a central angle of the reference partial arc is not less than 5 ° and not more than 15 °. To do.

  As a result, the machining data creation apparatus of the ninth invention of the present application can prevent the gear shape curve curvature in the approximate data from becoming excessively small or excessive, and realize an appropriate gear shape.

  In order to achieve the above object, a tenth aspect of the present invention is a machining data creation method for machining a gear shape for a gear base material or a gear working die, and a condition for defining the gear shape. A coordinate calculation procedure for calculating a plurality of coordinate points sequentially including a first coordinate point, a second coordinate point, and a third coordinate point located in the outer shape locus of the gear shape based on the data; the first coordinate point; A radius calculation procedure for calculating a radius line connecting the center point of the first partial arc passing through the second coordinate point and the second coordinate point; and the line segment connecting the second coordinate point and the third coordinate point. A vertical bisector calculation procedure for calculating a vertical bisector, an intersection calculation procedure for calculating an intersection of the radial straight line and the vertical bisector, and the intersection calculated by the intersection calculation means as a center. , The distance from the center point to the second coordinate point is the radius The partial arc, and having a circular-arc data creation procedure to approximate data of the outline trace of the gear shape from the second coordinate point to the third coordinate point.

  In the processing data creation method according to the tenth aspect of the present invention, when the operator inputs condition data, the coordinate calculation procedure calculates a plurality of coordinate points including the first, second, and third coordinate points. Thereafter, the radius calculation procedure calculates a radial straight line connecting the first partial arc and the second coordinate point, while the vertical bisector calculation procedure calculates the vertical bisector of the line segment connecting the second third coordinate point. calculate. Then, the intersection calculation procedure calculates the intersection of the radial straight line and the perpendicular bisector, and the arc data creation procedure creates a second partial arc centered on the intersection to create the third coordinate from the second coordinate point. Approximate data of the outer shape locus of the gear shape up to the point. As a result, the first partial arc from the first coordinate point to the second coordinate point and the second partial arc from the second coordinate point to the third coordinate point share the same tangent line (in other words, the tangent line is the same). The positional relationship is as follows. As a result, the ends (butt ends) of these two partial arcs are always perpendicular to the respective radial lines.

  Machining machines (wire electric discharge machines, die-sinking electric discharge machines, milling machines such as end mills, etc.) are based on the approximate data of the outer shape locus of the gear shape created using partial arcs as described above. Alternatively, a gear shape is formed for the mold.

  Here, for example, in the case of wire electric discharge machining, it is necessary to drive (relatively) the wire in a positional relationship in which the wire is offset by the wire diameter + discharge gap with respect to the outer shape of the gear. The same offset drive is required also in the die-sinking electric discharge machine and milling machine using the above-mentioned electrode.

  In the data generation method of the tenth invention of the present application, as described above, when generating approximate data, a gear-shaped outer locus is formed so that the ends of the two partial arcs are always perpendicular to the respective radial lines. To do. Thus, the processing machine can reliably form the gear outline by driving (relatively) the wire or the like in a positional relationship in which the two partial arcs are simply shifted in the radial direction by the offset. Therefore, the processing machine can prevent the occurrence of variations in gear shape.

  In order to achieve the above object, the processing data creation program of the eleventh aspect of the invention is based on condition data for defining a gear shape to be processed for a gear base material or a gear working die in a computer. A coordinate calculation procedure for calculating a plurality of coordinate points sequentially including a first coordinate point, a second coordinate point, and a third coordinate point located in a gear-shaped outer locus; and the first coordinate point and the second coordinate point A radius calculation procedure for calculating a radial straight line connecting the center point of the first partial arc passing through the second coordinate point, and the vertical bisector connecting the second coordinate point and the third coordinate point A vertical bisector calculation procedure for calculating a cross point, a cross point calculation procedure for calculating a cross point between the radial straight line and the vertical bisector, and the cross point calculated by the cross point calculation means as a center, from the center point A second part whose radius is the distance to the second coordinate point Circular arc, to execute an arcuate data creation procedure to approximate data of the outline trace of the gear shape from the second coordinate point to the third coordinate point.

  When an operator inputs condition data to a computer provided with the machining data creation program of the eleventh invention of the present application, the computer executes a coordinate calculation procedure, and a plurality of coordinate points including the first, second, and third coordinate points are obtained. calculate. Thereafter, the computer executes a radius calculation procedure to calculate a radial straight line connecting the first partial arc and the second coordinate point, while executing a vertical bisector calculation procedure to connect the second third coordinate point. Calculate the perpendicular bisector of the minute. Then, the computer executes the intersection calculation procedure to calculate the intersection between the radius straight line and the perpendicular bisector, and executes the arc data creation procedure to create a second partial arc centered on the intersection. The approximate data of the outer shape locus of the gear shape from the second coordinate point to the third coordinate point is used. As a result, the first partial arc from the first coordinate point to the second coordinate point and the second partial arc from the second coordinate point to the third coordinate point share the same tangent line (in other words, the tangent line is the same). The positional relationship is as follows. As a result, the ends (butt ends) of these two partial arcs are always perpendicular to the respective radial lines.

  Machining machines (wire electric discharge machines, die-sinking electric discharge machines, milling machines such as end mills, etc.) are based on the approximate data of the outer shape locus of the gear shape created using partial arcs as described above. Alternatively, a gear shape is formed for the mold.

  Here, for example, in the case of wire electric discharge machining, it is necessary to drive (relatively) the wire in a positional relationship in which the wire is offset by the wire diameter + discharge gap with respect to the outer shape of the gear. The same offset drive is required also in the die-sinking electric discharge machine and milling machine using the above-mentioned electrode.

  As described above, the computer executing the program according to the eleventh aspect of the present invention has a gear-shaped contour locus so that the ends of the two partial arcs are always perpendicular to the respective radial lines when generating approximate data. Form. Accordingly, the processing machine can reliably form the gear outline by driving (relatively) the wire or the like in a positional relationship in which the two partial arcs are simply shifted in the radial direction by the offset. Therefore, the processing machine can prevent the occurrence of variations in gear shape.

  According to the present invention, it is possible to prevent occurrence of variations in gear shape.

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

  FIG. 1 is a conceptual diagram showing the overall configuration of an embodiment of a processing data creation apparatus of the present invention.

  In FIG. 1, a processing data creation device 100 of this embodiment is for creating processing data to be given to a processing device (processing machine) for processing a gear cavity in a gear-making mold. . In the processing data creation device 100 of the present embodiment, a case where a wire electric discharge machine (not shown) is used as the processing device will be described as an example.

  The processing data creation device 100 includes a keyboard 5 as input means for inputting condition data that defines the shape of the gear, and an arithmetic device 1 as data creation means for creating approximate data of the external locus of the gear. A graphic display device 3 as a display means for displaying the approximate data created by the arithmetic device 1 as a graphic, and a mouse 7 for specifying the approximate data displayed on the graphic display device 3 are provided. is doing. In this example, the machining data creation device 100 is also provided with an NC puncher 9 that punches a machining NC program including approximate data created by the arithmetic device 1 on an NC tape.

  FIG. 2 is a functional block diagram showing a functional configuration of the arithmetic device 1.

  In FIG. 2, the arithmetic unit 1 is composed of a CPU 11, a ROM 13 storing a machining data creation program of the present invention according to the principle method described later, a RAM 15, an input / output circuit 17, a bus line 19 and the like. Yes. The graphic display device 3, keyboard 5, mouse 7, and NC tape puncher 9 are connected to the input / output circuit 17, and a hard disk device 21 built in the arithmetic device 1 and a floppy disk device 23 are connected. Has been. These hard disk device 21 and floppy disk device 23 store the created NC program for machining.

  Note that the machining data creation apparatus 100 and the wire electric discharge machine can be connected to transmit the machining NC program to the wire electric discharge machine. In this case, the communication circuit 25 is used, and the data creation device 100 and the wire electric discharge machine are connected via the communication circuit 25.

  Next, the principle of the approximate data, which is a main part of the present embodiment, will be described with reference to FIGS.

(A) Arc Forming Method FIG. 3 is an explanatory diagram for explaining a gear shape approximation method. In FIG. 3, when the condition data defining the shape of the gear is input from the keyboard 5, the CPU 11 is located in the outer shape locus L of the gear, that is, on the outer shape locus L, and a plurality of coordinate points that define the outer shape locus L. The coordinates of P1, P2, P3,... Are calculated from the condition data. Thereafter, the CPU 11 successively uses arcs s1, s2, s3,... Of radii r1, r2, r3,... Passing through two adjacent coordinate points P1, P2, P2, P3,. Approximate data of the locus L is created.

  At this time, the CPU 11 sequentially determines the arcs s2, s3,... While the adjacent two arcs s share the same tangent line and are connected to each other at the contact point to the tangent line (note that The arc s1 is set based on another concept (described later). The first coordinate point P1 to the third coordinate point P3 will be described as an example. First, a partial arc (first partial arc) s1 passing through the first coordinate point P1 and the second coordinate point P2 is determined by a separate method. Thereafter, an arc (second partial arc) s2 passing through the second coordinate point P2 and the third coordinate point P3 is connected to the arc s1 while sharing the same tangent line k as the arc s1 at the second coordinate point P2. To be determined. By determining the arc s2, approximate data from the second coordinate point P2 to the third coordinate point P3 is calculated.

  FIG. 4 is an explanatory diagram for explaining the method using the common tangent in more detail. In FIG. 4, a point O1 (α1, β1) on an arbitrary coordinate at a position inside the outer shape locus L of the gear is taken as an origin (α1 = 0, β1 = 0), and an xy coordinate system passing through the origin O1 is considered. In this coordinate system, the coordinates of the coordinate points P1, P2, P3,... Are P1 (X1, Y1), P2 (X2, Y2), P3 (X3, Y3),. The coordinates of the coordinate point P (P1, P2, P3,...) On the xy coordinate system are calculated by the CPU 11 from the above condition data that defines the shape of the gear if the coordinate position of the point O1 on the arbitrary coordinate is determined. (Coordinate calculation means).

  First, the CPU 11 sets the radius r1 of the arc s1 passing through the coordinate points P1 and P2 with the origin O1 (α1 = 0, β1 = 0) on the xy coordinate system as the center (reference arc setting means). The arc s1 is a reference partial arc that serves as a calculation reference in creating data of the arcs s2, s3,. The center of the arc s1 and its radius r1 can be obtained and set by calculation using the center angle θ by giving the center angle θ of the arc s1 since the coordinates of the coordinate points P1 and P2 are known ( Second center determining means, radius determining means).

  The central angle θ of the reference arc s1 is preferably selected to be a constant value within a range of θ = 5 ° to 15 °. In this embodiment, θ = 10 °. Thus, by setting the central angle θ of the reference arc s1 in the range of 5 ° to 15 °, it is possible to prevent the curvature of the gear shape curve in the approximate data from becoming excessively small or excessively large. An appropriate gear shape can be realized.

  Next, assuming that the coordinate point P2 is a start coordinate point used for data generation of the next arc s2, and a straight line connecting the coordinate point P2 (X2, Y2) and the origin O1 (0, 0) is h1, The straight line h1 is a radial straight line of the arc s1, and can be obtained by the equation (1) (radius calculation means).

y = x * Y2 / X2 (1)
Next, a perpendicular bisector m of a line segment g connecting the coordinate point P2 (X2, Y2) and the coordinate point P3 (X3, Y3) is obtained. The line segment g can be obtained by the equation (2) (line segment calculating means).

y = xx * (Y2-Y3) / (X2-X3) + (X2Y3-X3Y2) / (X2-X3) (2)
Since the coordinates of the midpoint M of the line segment g can be obtained by M ((X2 + X3) / 2, (Y2 + Y3) / 2) (middle point calculation means), the vertical bisector m of the line segment g is (Vertical bisector calculation means, first center determination means).

y = -x * (X2-X3) / (Y2-Y3) + {(X2 + X3) (X2-X3) + (Y2 + Y3) (Y2-Y3)} / 2 (Y2-Y3) (3)
Next, the intersection of the extension of the straight line h1 and the straight line m is defined as O2 (α2, β2) (intersection calculation means, first center determination means), and an arc s2 passing through the coordinate points P2, P3 is drawn with the intersection O2 as the center. This arc s2 can be obtained by the following equations (4) to (6).

That is, the size of the radius r2 of the arc s2 is (x−α2) ² + (y−β2) ² = r2 ²
r2 = √ {x−α2) ² + (y−β2) ² } (4)
(Radius calculation means, first center determination means).

However,
Equation (3) of the perpendicular bisector m is expressed as y = ax + b
a =-(X2-X3) / (Y2-Y3)
b = {(X2 + X3) (X2-X3) + (Y2 + Y3) (Y2-Y3)} / 2 (Y2-Y3)
As
α2 = bX2 / (Y2-aX2)
= {(X2 + X3) (X2-X3) + (Y2 + Y3) (Y2-Y3)}
/ 2 (Y2-Y3) / {2Y2 (Y2-Y3) + (X2-X3)}
... (5)
β2 = α2 / Y2 / X2
= Y2 {(X2 + X3) (X2-X3) + (Y2 + Y3) (Y2-Y3)}
/ 2 (Y2-Y3) / [X2 {2Y2 (Y2-Y3) + (X2-X3)}]
(6)
It is.

  Here, since the radial line h1 of the circular arc s1 and the radial line h2 of the circular arc s2 overlap and are on the same straight line, the two circular arcs s1 and s2 share the same tangent at the coordinate point P2. The ends of the two arcs s1 and s2 are perpendicular to the respective radial lines h1 and h2.

  As described above, the data of the arc s2 passing between the coordinate points P2 and P3 is created using the arc s1 as the reference partial arc and the coordinate point P2 as the start coordinate point of the data creation of the arc s2 (arc data). Creating means). Such a method of creating an arc is repeated thereafter. That is, the arc s2 is set as a new reference partial arc, and the coordinate point P3 is set as a new start coordinate point for generating the data of the arc s3, and the data of the arc s2 passing between the coordinate points P2 and P3 is generated as described above. To do. In this way, by sequentially repeating the creation of a similar arc for a plurality of coordinate points P1, P2, P3, P4,... On the outer shape locus L, as shown in FIG. Can be obtained by approximating the external locus L of the gear using arcs s1, s2, s3,... Formed so as to be perpendicular to the respective radial lines.

(B) Comparison with conventional methods For example, in the case of wire electric discharge machining, the wire of the electric discharge machine needs to be driven relatively in a positional relationship that is offset by ΔD = wire diameter + discharge gap with respect to the outer shape of the gear. There is.

  An example of the conventional method at this time will be described with reference to FIGS.

  In FIG. 6, for example, in the conventional method, an arc s1 'passing through coordinate points P1, P2 on the outer contour L of the gear, an arc s2' passing through coordinate points P2, P3, an arc s3 'passing through coordinate points P3, P4,. Is drawn in an appropriate shape along the outer shape locus L of the gear for each coordinate point, and is used as approximate data of the outer shape locus L of the gear. At this time, as in the present embodiment, there is no particular consideration that adjacent arcs have a common tangent.

  Therefore, normally, as shown in FIG. 7, two adjacent arcs, for example, arcs s1 'and s2' (in the illustration, arcs s1 'and s2' will be described as an example, but arcs s2 'and s3' are the same. In other words, the radius line h1 ′ of the arc s1 ′ passing through the coordinate point P2 and the radius line h2 ′ of the arc s2 ′ do not lie on the same straight line but intersect at the coordinate point P2. As a result, the wire drive data of the wire electric discharge machine described above, that is, drive data for relatively driving the wire in the positional relationship shifted by the offset ΔD (wire diameter + discharge gap) with respect to the outer shape of the gear. At the time of creation, there are two drive data for the arc s1 'and for the arc s2' in the vicinity of the coordinate point P2, and the drive data cannot be determined in the vicinity of the coordinate point P2. Such a problem also applies to the other coordinate points P3, P4,. For this reason, in the conventional method, for example, the operator of the electric discharge machine creates the drive data in the vicinity of the coordinate point P2 at his / her own discretion, and performs machining. There is a possibility that variations occur at the respective coordinate points P1, P2, P3,.

  On the other hand, in this embodiment, as described in the above (a), arcs s1, s2, s3,... Passing through a plurality of coordinate points P1, P2, P3,. Approximate data of the outer shape locus L of the gear is created while the ends of the two arcs that meet each other are perpendicular to the respective radial lines h1, h2, and h3. Therefore, in two adjacent arcs, for example, arcs s1 and s2, the radius line h1 of the arc s1 and the radius line h2 of the arc s2 passing through the coordinate point P2 common to both are located on the same straight line, and the coordinate point P2 Never cross. As a result, unlike the above, even if drive data that is relatively driven with a positional relationship shifted by the offset ΔD is created, the drive data for the arc s1 and the drive data for the arc s2 are 2 at the position of the coordinate point P2. It will not be connected (see FIG. 5). That is, the two arcs s1 and s2 may be driven in a positional relationship in which they are simply shifted in the radial direction by the offset ΔD (the same applies to the arcs s3 and below). Therefore, it is possible to prevent the variation in the shape of the gear at the coordinate points P1, P2, P3,.

  Next, control contents of the data creation device 100 of the present embodiment based on the above principle will be described. FIG. 8 is a flowchart showing a control procedure executed by the arithmetic device 1 based on the machining data creation program stored in the ROM 13 in the data creation device 100 of the present embodiment.

  In FIG. 8, first, in step S10, condition data input processing for defining the shape of the gear is performed. At this time, input requests for condition data are sequentially displayed on the screen of the graphic display device 3, and the operator of the wire electric discharge machine inputs each condition data from the keyboard 5 in accordance with the input request displayed. The input condition data is stored in the RAM 15.

  Next, in step S100, approximate data of the gear contour locus is calculated from the condition data input in step S10 in accordance with the principle described above (refer to FIG. 9 described later for details).

  Thereafter, in step S30, the figure of the gear is reproduced based on the approximate data calculated in step S100, and a display control signal including the reproduced figure of the gear is output to the figure display device 3 (output means). To display. The operator of the wire electric discharge machine creates a gear machining program for the wire electric discharge machine in step S40 by performing an appropriate operation with the keyboard 5 and the mouse 7 in response to the display on the display screen. Is transmitted to the wire electric discharge machine via the communication line 25, for example, and this flow is terminated.

  FIG. 9 is a flowchart showing the detailed procedure of step S100.

  In FIG. 9, first, in step S110, the coordinates of coordinate points P1 to Pz located on the external locus L of the gear are calculated from the condition data defining the shape of the gear input in step S10 of FIG. Coordinate calculation means). Here, the coordinate point P1 is a start point in the generation of approximate data on the outer shape locus L of the gear, and Pz is an end point. The coordinates of the calculated coordinate points P1 to Pz are stored in the RAM 15.

  Next, in step S120, the CPU 11 reads the coordinates of the coordinate points P1 (X1, Y1) and P2 (X2, Y2) among the coordinates stored in the RAM 15 in step S110.

  Thereafter, in step S130, a reference arc s1 having a central angle θ (for example, θ = 10 ° in this example) passing through the coordinate points P1 and P2 is calculated in accordance with the principle described above. As described above, the calculation in step S130 constitutes the second center determining means and the radius determining means described in the claims, and also constitutes the reference arc setting means.

  In step S140, an operator n = 2 indicating the order of the coordinate points Pn is set. Thereafter, in step S150, the coordinates of the coordinate point Pn + 1 (Xn + 1, Yn + 1) stored in the RAM 15 in step S10 are read into the CPU 11.

  Next, in step S160, if the arc sn (eg, n = 2) passing through the coordinate points Pn (Xn, Yn) and Pn + 1 (Xn + 1, Yn + 1) according to the above equations (1) to (6), An arc s2) passing through the coordinate points P2 and P3 is calculated (arc data creating means). As described above, the calculation of equation (1) executed in step 160 at this time constitutes the radius calculation means described in each claim, and the calculation of equation (2) calculates the line segment described in each claim. Configure the means. Further, the calculation according to the equation (3) constitutes the midpoint calculation means described in each claim and also constitutes a perpendicular bisector calculation means (in other words, a part of the first center determination means). Further, the calculations according to the equations (4) to (6) constitute an intersection calculation unit and a radius calculation unit (in other words, a part of the first center determination unit) described in each claim.

  Next, in step S170, whether n + 1 obtained by adding 1 to the operator n representing the order of the coordinate points P is greater than the operator z representing the end points of the coordinate points (in other words, whether n is greater than z-1). Determine. If n + 1 ≦ z, the determination in step S170 is not satisfied, 1 is added to the operator n in step S180, and the process returns to step S150 and the same procedure is repeated. That is, before n reaches z, the coordinates of the coordinate point Pn + 1 (Xn + 1, Yn + 1) in step S150 are read and the arc passing through the coordinate points Pn and Pn + 1 in step S160 is calculated. repeat.

  The above is repeated while adding 1 to n. When calculation of the arc passing through the coordinate point Pz-1 immediately before the end point and the coordinate point Pz at the end point is completed, n + 1 becomes larger than z. As a result, the determination in step S170 is satisfied, and this flow ends.

  FIG. 10 shows a control procedure executed by the control device (not shown) of the wire electric discharge machine when the wire electric discharge machine operates based on the program created by the arithmetic device 1 as described above. It is a flowchart.

  In FIG. 10, first, in step S50, the gear machining program transmitted from the data creation device 100 is received through the communication circuit 25, for example, as described above.

  Thereafter, the process proceeds to step S60, and a driving program is generated by adding the above-described offset (wire diameter + discharge gap) to the above-mentioned approximate data of the gear outline locus included in the gear machining program.

  In step S70, the operation is performed according to the driving program generated in step S60, and the gear mold is subjected to electric discharge machining to form a cavity according to the outer shape of the gear in the mold (details are omitted).

  As described above, according to the machining data creation device 100 of the present embodiment, two adjacent arcs s (s1) of a plurality of coordinate points P (P1, P2, P3,...) On the outer shape locus L of the gear. , S2, s3,...), Approximate data of the gear outline trajectory is created so that the ends of the radial lines are always perpendicular to the respective radial lines. As a result, the wire electric discharge machine can reliably form the outer shape of the gear only by relatively driving the wires in a positional relationship in which the two partial arcs are shifted in the radial direction by the offset amount (see FIG. 5). ). Therefore, it is possible to prevent the occurrence of gear shape variations in the wire electric discharge machine.

  In addition, although the case where the metal mold | die of a gear production effect | action was produced by the wire electrical discharge machining was demonstrated as an example above, this invention is not limited to this. That is, the present invention may be applied when the gear itself is processed from the gear base material by wire electric discharge machining. Further, the machining method is not limited to wire electric discharge machining, and can also be applied to electric discharge machining for die-cutting, milling using an end mill, and the like. In these cases, the same effect is obtained.

It is a conceptual diagram which shows the whole structure of one Embodiment of the data creation apparatus for a process of this invention. It is a block diagram which shows the structure of the arithmetic unit of the data preparation apparatus of FIG. It is explanatory drawing which shows the approximate data preparation method of the external shape locus | trajectory of the gearwheel by the data preparation apparatus of FIG. It is detailed explanatory drawing of the approximate data preparation method of the external shape locus | trajectory of a gearwheel. It is explanatory drawing for demonstrating the wire drive data of the electric discharge machine produced based on the approximate data of the external shape locus | trajectory of the gear produced with the data production apparatus of FIG. It is explanatory drawing which shows the approximate data creation method of the external shape locus | trajectory of a gear by the conventional method. It is explanatory drawing for demonstrating the wire drive data of the electric discharge machine produced based on the approximate data of the external shape locus | trajectory of the gear produced with the conventional method. It is a flowchart which shows the control procedure performed with the arithmetic unit of the data preparation apparatus of FIG. It is a flowchart which shows the detail of step S100 of FIG. It is a flowchart which shows the control procedure performed with the control apparatus of a wire electric discharge machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Arithmetic unit 3 Graphic display device 5 Keyboard 11 CPU
100 Machining data creation device ΔD Offset L Gear outline locus h1 to h3 Radial line O1 Coordinate origin P1 to P4 Coordinate point r1 to r3 Radius s1 to s3 Arc

Claims (11)

Display means for displaying data for processing a gear shape on a gear base material or a gear working mold;
Input means for inputting condition data for defining the gear shape;
Based on the condition data inputted by the input means, the approximate data of the outer shape locus of the gear shape is created by successively using two partial arcs that share the same tangent and are connected to each other at the contact point to the tangent. Data creation means,
A processing data creation apparatus comprising: output means for outputting a gear shape based on the approximate data created by the data creation means to the display means. In the processing data creation device according to claim 1,
The data creation means includes
Coordinate calculating means for calculating a plurality of coordinate points that are located in the outer shape locus of the gear shape and sequentially include a first coordinate point, a second coordinate point, and a third coordinate point;
The first partial arc passing through the first coordinate point and the second coordinate point and the second partial arc passing through the second coordinate point and the third coordinate point are tangent to the second coordinate point. The processing data creation device is characterized in that the approximate data from the first coordinate point to the third coordinate point is created by connecting to the processing data. In the processing data creation device according to claim 2,
The data creation means includes
An intersection of a straight line connecting the center point of the first partial arc and the second coordinate point and a perpendicular bisector connecting the second coordinate point and the third coordinate point is defined as the second partial arc. A processing data creation device comprising first center determining means for determining a center point of the first center determining means. In the processing data creation device according to claim 3,
The first center determining means includes
Radius calculating means for calculating a straight line connecting the center point of the first partial arc and the second coordinate point;
Vertical bisector calculation means for calculating the vertical bisector of the line segment connecting the second coordinate point and the third coordinate point;
An machining data creation device comprising: an intersection calculation means for calculating an intersection between the radial straight line and the perpendicular bisector. In the processing data creation device according to claim 4,
The vertical bisector calculation means includes:
A line segment calculating means for calculating a line segment connecting the second coordinate point and the third coordinate point;
A machining data creation device comprising: a midpoint calculating means for calculating a midpoint of the line segment, and calculating a straight line passing through the midpoint and orthogonal to the line segment as the perpendicular bisector. In the processing data creation device according to any one of claims 3 to 5,
The data creation means includes
The second partial arc having the center point determined by the first center determining means as a center and the distance from the center point to the second coordinate point as a radius is defined from the second coordinate point to the third coordinate point. A processing data creation device comprising arc data creation means for the approximate data up to. The processing data creation device according to any one of claims 2 to 6,
The data creation means includes
A processing data creation device comprising reference arc setting means for setting a reference partial arc as a calculation reference in the creation of data of partial arcs that are sequentially and continuously used based on the condition data input by the input means . In the processing data creation device according to claim 7,
The reference arc setting means includes
Second center determining means for determining a center point of the reference partial arc passing through a start coordinate point used when starting data generation among the plurality of coordinate points and the first coordinate point corresponding to the start coordinate point;
Radiation determining means for determining a radius of the reference partial arc. In the processing data creation device according to claim 8,
The radius determining means includes
The processing data creation apparatus, wherein the radius of the reference partial arc is set so that a central angle of the reference partial arc is 5 ° or more and 15 ° or less. A machining data creation method for machining a gear shape for a gear base material or a gear working die,
Coordinate calculation for calculating a plurality of coordinate points sequentially including a first coordinate point, a second coordinate point, and a third coordinate point located in the outer shape locus of the gear shape based on condition data for defining the gear shape Procedure and
A radius calculation procedure for calculating a radius line connecting a center point of a first partial arc passing through the first coordinate point and the second coordinate point and the second coordinate point;
A vertical bisector calculation procedure for calculating the vertical bisector of a line segment connecting the second coordinate point and the third coordinate point;
An intersection calculation procedure for calculating an intersection between the radial straight line and the perpendicular bisector;
A second partial arc whose center is the intersection calculated by the intersection calculation means and whose radius is the distance from the center to the second coordinate point is a gear shape from the second coordinate point to the third coordinate point. A method for creating machining data, comprising: arc data creation procedure for approximating the outline locus of On the computer,
A first coordinate point, a second coordinate point, a third coordinate point located within the outer shape locus of the gear shape, based on condition data for defining a gear shape to be processed for a gear base material or a gear making die. A coordinate calculation procedure for calculating a plurality of coordinate points sequentially including coordinate points;
A radius calculation procedure for calculating a radius line connecting a center point of a first partial arc passing through the first coordinate point and the second coordinate point and the second coordinate point;
A vertical bisector calculation procedure for calculating the vertical bisector of a line segment connecting the second coordinate point and the third coordinate point;
An intersection calculation procedure for calculating an intersection between the radial straight line and the perpendicular bisector;
A second partial arc whose center is the intersection calculated by the intersection calculation means and whose radius is the distance from the center to the second coordinate point is a gear shape from the second coordinate point to the third coordinate point. Processing data creation program for executing a circular arc data creation procedure as approximate data of the outer shape locus of.

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