JP2001092513A - Method of generating tool route in working machine, and computer-readable recording medium recording tool route generation program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a tool route generation method prepared for generating a tool route and capable of surely judging a no-load cutting tool route and sharply shortening the working time by moving a tool in a no-load cutting section by the shortest distance and a recording medium recording a tool route generation program. SOLUTION: Working simulation is executed on the basis of the shape data of a work to be worked and an initial tool route (100), the removing shape of the work is derived on the basis of the result of the working simulation (102) and a no-load cutting tool route is judged on the basis of the removing shape (104). One or plural two-connection points to be two-connection points in the continuous section of the no-load cutting tool route and generating no interference between a tool system and a work system are extracted (106), points between the extracted two-connection points are deleted and a tool moving speed between the two-connection points is increased (108).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for generating a tool path in a processing machine and a computer-readable recording medium on which a program for generating a tool path is recorded, and more particularly, to a tool path capable of shortening a processing time. The present invention relates to a tool path generation method that can be generated with high accuracy, and a computer-readable recording medium that records a tool path generation program.

[0002]

2. Description of the Related Art In general, when performing NC (numerical control) processing on a work (workpiece) by a processing machine, first, CAD (CAD) processing is performed.
The system designs the shape of the product, and the CAM system generates CL data, which is information indicating a tool path along the product shape designed by the CAD system.

[0003] The "NC data" is obtained by converting the CL data into code data peculiar to a processing machine, and processing of the workpiece is started by transferring the NC data to a controller of the processing machine.

On the other hand, conventionally, in order to improve the reliability of NC machining, prior to actual machining of a workpiece,
An NC processing simulator has been developed in which the processing is simulated by a computer and the processing state is verified by graphically displaying the result on a display or the like.

[0005] The form data of a workpiece that can be used in this type of simulator includes a B-rep approximating a polyhedron, a PIXEL approximating a pixel unit, and a VOXE combining a rectangular parallelepiped and a cube.
There are various types such as a format based on the L method. There is an approximation error in the form of each of these shape data, but the accuracy is sufficient for performing a visual simulation by a graphic display or the like.

When performing the above-described NC machining, since the machining is usually started from a simple shaped material such as a rectangular parallelepiped, for example, the shaped material is determined from the machining range by the tool path obtained by CAD / CAM. Is smaller, there is a path (hereinafter, referred to as an empty cutting tool path) on the outer periphery of the shaped material where no processing is performed. Further, depending on the relationship between the shaped material and the tool path, an empty cutting tool path may be generated in addition to the outer periphery. In general, the tool moving speed in the empty cutting tool path is the same as the speed in the path in which actual machining is performed (hereinafter, referred to as an actual cutting tool path). It was moved late and wasted machining time wasted.

As a technique which can be applied to solve the problem of prolonged machining time due to such factors, Japanese Patent Application Laid-Open No.
There are techniques described in Japanese Patent Publication Nos. 90774 and 7-112221.

The technique described in Japanese Patent Application Laid-Open No. H11-90774 obtains the machining volume of each tool path one point based on the volume information of the shape data by applying the above-described simulation technique, and obtains the bending of the tool. Is to optimize the tool moving speed according to.

The technique described in Japanese Patent Application Laid-Open No. 7-112221 is intended to reduce the number of empty cutting tool paths, and uses a type of VOX called an area map as a form of shape data.
The shape of the work is approximated by using the EL method, and the tool ascending position in the empty cutting tool path is limited by the maximum protrusion value of the area map.

[0010]

However, the technique described in Japanese Patent Application Laid-Open No. H11-90774 is for optimizing the tool moving speed by simulation as described above. However, there is a problem that it has a great influence on the above-mentioned machining volume, and it is difficult to accurately optimize the tool moving speed. For example, in a portion where the distance between the points of the tool path is smaller than the approximation error of the shape data, the work volume does not change because the workpiece shape does not change even though the machining is actually performed. In such a case, it is determined that there is no load, and the tool moving speed is optimized in the increasing direction. Therefore, when the tool is moved, a large load is applied to the tool, and there is a risk that the tool is broken or scattered.

This problem is specifically described as follows. V approximating a rectangular parallelepiped as the data format of the work shape
When a simulation is performed using the OXEL method, FIG.
As shown in FIG. 7, the tool path 2 that passes through the portion removed by the tool path 1, that is, the tool path 2 in which the point-to-point distance L <approximate error ε has a machining volume despite the fact that machining is actually performed. It becomes zero, which is erroneously determined as an empty cutting tool path. This is a common problem when an approximation method is applied as a data format, such as a B-rep approximating to a polyhedron, a PIXEL method approximating to a pixel unit, and a VOXEL method approximating to a rectangular parallelepiped or a cube.

As described above, in general, when determining an empty cutting tool path by simulation, the workpiece shape does not change in a portion where the distance between points of the tool path is smaller than the approximation error of the shape data. However, it is erroneously determined that the path is an empty cutting tool path. As described above, when the actual cutting tool path is erroneously determined as the empty cutting tool path, the actual cutting tool path is
It increases the tool moving speed, causing serious defects in machining.

Conversely, if the empty cutting tool path is erroneously determined to be the actual cutting tool path, the tool moving speed cannot be increased despite the empty cutting tool path, resulting in wasted machining time. To increase.

When the approximation accuracy of the workpiece shape is increased in order to solve such a problem, although the frequency of erroneous determination of the empty cutting tool path decreases, it does not completely disappear.
Further, it is not practical because it is necessary to increase the storage capacity of the storage means such as a memory and the time required for the processing simulation is also increased.

On the other hand, the technique described in the above-mentioned Japanese Patent Application Laid-Open No. 7-112221 limits the tool ascending position when the tool moves between machining areas. There has been a problem that no improvement is made and a sufficient reduction in processing time cannot be realized.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to reliably determine an empty cutting tool path without being influenced by an approximation error of workpiece shape data, and to reduce machining time. It is an object of the present invention to provide a tool path generation method capable of generating a tool path capable of greatly reducing the length of a tool path, and a computer-readable recording medium recording a tool path generation program.

[0017]

According to a first aspect of the present invention, there is provided a method for generating a tool path in a processing machine, comprising: obtaining information indicating an initial tool path and a workpiece shape before processing. Removing the workpiece shape obtained based on the initial tool path from the workpiece shape before machining to thereby derive a removal shape by machining; and performing idle cutting based on the removal shape. An empty cutting tool path determining step of determining a tool path, and at one or a plurality of two connection points where interference does not occur between a tool system and a work system in a continuous section of the empty cutting tool path, and in the continuous section. 2 from start point to end point
The one or more 2 that minimize the total distance between connection points
The method includes a two connection point extracting step of extracting connection points, and a tool path generation step of generating a path formed by the extracted one or a plurality of two connection points as a final tool path.

According to the tool path generating method of the present invention, information indicating each of the initial tool path and the workpiece shape before machining is acquired by the information acquiring step, and the information is obtained from the workpiece shape before machining by the removal shape deriving step. By removing the workpiece shape after processing obtained based on the initial tool path, a removal shape by processing is derived.

In the tool path generating method according to the first aspect, the empty cutting tool path determining step determines the empty cutting tool path based on the removal shape derived in the removal shape deriving step, and extracts two connection points. In the continuous section of the empty cutting tool path determined in the empty cutting tool path determination step, the process is performed at one or a plurality of two connection points where no interference occurs between the tool system and the work system, and in the continuous section. The one or more two connection points that minimize the sum of the distances between the two connection points from the start point to the end point are extracted, and the one or more two or more connection points extracted in the two connection point extraction step are further extracted by a tool path generation step. Is generated as the final tool path. The tool system includes a tool, a holder, a quill, and a spindle head, and the work system includes a work, a table on which the work is placed, and a mounting jig for mounting the work at a predetermined work mounting position. It is.

That is, according to the first aspect of the present invention, as shown in FIG. 16 as an example, the interference between the tool system and the work system is determined based on the removed shape, that is, the maximum error that may exist in the work. Since the determination is performed for the range, the determination can be reliably performed even if the distance L between the points is smaller than the approximation error ε.

As described above, according to the tool path generating method of the first aspect, the empty cutting tool path is determined based on the removal shape, and the tool system and the work system are determined in a continuous section of the empty cutting tool path. 1 or a plurality of two connection points at which no interference occurs between the two and a minimum distance between two connection points from a start point to an end point in the continuous section.
Alternatively, since a plurality of two connection points are extracted and a path formed by the extracted one or more two connection points is generated as a final tool path, it is possible to reliably determine an empty cutting tool path. And a tool path capable of moving the idle cutting section by the shortest distance and greatly reducing the machining time can be generated.

According to a second aspect of the present invention, in the first aspect of the present invention, the step of generating the tool path includes the step of generating the extracted one or more of the information indicating the final tool path. It is characterized by adding information for increasing the tool moving speed between a plurality of two connection points.

According to the tool path generating method of the second aspect, the information indicating the final tool path is extracted by the two connection point extracting step in the tool path generating step of the first aspect. Information for increasing the tool moving speed between one or a plurality of two connection points is added.

As described above, according to the tool path generating method of the second aspect, the same effect as that of the first aspect of the invention can be obtained, and the information indicating the final tool path can be Since information for increasing the tool moving speed between the extracted one or a plurality of two connection points is added, it is possible to generate a tool path that can further reduce the machining time.

The computer-readable recording medium storing the tool path generating program according to the third aspect is a recording medium storing a program for causing a computer to operate in the same manner as the first aspect of the present invention. Recording media include floppy disk, hard disk, C
A D-ROM, a magneto-optical disk, a magnetic tape, a ROM (Read Only Memory) and the like are included.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a method for generating a tool path in a processing machine according to the present invention will be described in detail with reference to the drawings. First, a configuration of a machining system 10 to which a tool path generation method of the present invention is applied will be described with reference to FIG.

As shown in FIG. 1, the processing system 10 according to the present embodiment includes a CAM system 20, a processing machine controller 30, and a processing machine 40.

The CAM system 20 generates CL data, which is information indicating a tool path, based on the shape data generated by a CAD system (not shown).
Is converted into a unique code (NC data 22) and output to the processing machine controller 30.

The processing machine controller 30 includes a CPU 32 which controls the entire operation of the processing machine controller 30,
A ROM 34 in which programs executed by the PU 32 and various parameters are stored in advance, and a RAM (random access memory) 35 used as a work area and the like when the CPU 32 executes the various programs are provided. After generating control point data 36 for controlling the operation of the processing machine 40 based on the NC data 22 thus obtained, new control point data 38 in which the control point data 36 is optimized is generated and output to the processing machine 40. Is what you do.

Further, the processing machine 40 includes a processing machine controller 3
A digital-to-analog converter 42 that converts the new control point data 38, which is digital data input from 0, into analog data, and various motors 44 that are driven based on the analog data obtained by the digital-to-analog converter 42, Provided, and new control point data 38 inputted from the processing machine controller 30.
Based on the above, the workpiece is cut.

The processing machine 40 includes a spindle head 5 shown in FIG.
2, a tool system 50 including a quill 54, a holder 56, and a tool 58 (not shown in FIG. 1) is provided, and the processing machine 40 drives the various motors 44 to move the tool system 50. The workpiece is cut by controlling the rotational driving of the tool 58 and the tool 58.

Next, an operation when the processing machine controller 30 according to the present embodiment generates the new control point data 38 will be described with reference to FIG.

FIG. 3 shows the CAM system 20 to N
FIG. 9 is a flowchart of a tool path generation program executed by the CPU 32 after the C data 22 is input, the control point data 36 is generated based on the NC data 22 and stored in a predetermined area of the RAM 35. It is stored in the ROM 34 in advance. Therefore, ROM
34 corresponds to the recording medium of the present invention.

In this case, the data using the VOXEL method is applied as the data format of the work shape, and the state of the work (formed material) is a rectangular parallelepiped as shown in FIG. Generated control point data 3
6 (Equivalent to the initial tool path of the present invention)
Will be described with reference to FIG. 4, in which the plane of the work 12 is machined.

In step 100 of FIG. 3, the shape data of the workpiece before machining is input, and based on the shape data and the data indicating the tool path included in the control point data 36,
Perform processing simulation.

As described above, the shape of the work 12 before processing is a rectangular parallelepiped shown in FIG. When a machining simulation is performed on the workpiece 12 using the tool path shown in FIG. 4, the shape of the workpiece 12 after machining is as shown in FIG.

In the next step 102, when the work 12 is machined, the shape of the portion removed from the work 12 by the machining (hereinafter referred to as the "removed shape") is determined.
It is derived by removing the shape of the work 12 after processing (see also FIG. 6) from the shape of the work 12 before processing (see also FIG. 5). Thereby, the removal shape shown in FIG. 7 is obtained.

In the next step 104, the above step 1
The determination of the empty cutting tool path is performed based on the removal shape obtained in step S02.

In step 104, it is determined that the tool path overlapping with the removed shape is the actual cutting tool path, and that the tool path not overlapping with the removed shape is the empty cutting tool path. As a result, an actual cutting tool path shown by a black circle in FIG. 8 and an empty cutting tool path shown by a white circle in FIG. 8 are obtained. FIG. 8 shows the actual cutting tool path and the empty cutting tool path for the removed shape in plan view.

In the next step 106, the above step 1
Based on the empty cutting tool path obtained in step 04, one or a plurality of two connection points in a continuous section of the empty cutting tool path are extracted. Hereinafter, with reference to FIGS. 9 to 12, the process of extracting two connection points in step 106 will be described in detail.

First, as shown in FIG. 9, the section leading to the starting point P _{s (1)} point P ₁₆ from a continuous section of the air-cutting tool path (P
_{s (1)} , P ₁ , P ₂ ,..., P ₁₆ ), the tool system 50 between the starting point P _{S (1)} and the other points.
It is determined whether or not the tool system 50 and the work system (the pre-machining shape is applied as the work) interfere with each other when the tool moves linearly, and the result of this determination is used as a primary connection point in the RAM 35.
In a predetermined area.

FIG. 10 shows an example of the primary connection point. At the primary connection point shown in the figure, the starting point P _{s (1)}
Not interfere with the tool system 50 and the workpiece based in each corresponding segment to the distance L ₁ ~L ₁₃ between each point of the preparative point P ₁ to the point P _13, the start point P _{s (1)} and the point P ₁₄ It has been shown to interfere with each corresponding segment to the distance L ₁₄ ~L ₁₆ between each point to the point P ₁₆ from.

Next, based on the data indicating the primary connection point (see FIG. 10) stored in a predetermined area of the RAM 35, two connection points (start point Ps ₍₁₎ and point P _{1 )} determined not to interfere. for each point) to the point P ₁₃ from the viewpoint of the end point side of the second coupling point (point P ₁₆ side), moving between a tool system 50 is linearly between the points located on the end point side of this point Then, it is determined whether or not the tool system 50 and the work system interfere with each other, and this determination result is stored in a predetermined area of the RAM 35 as a secondary connection point.

[0044] For example, are stored those shown in FIG. 10 as the primary connection point, the corresponding second connection point to the distance L _11,
That is, when focusing on the starting point P _{s (1)} and the point P _11, FIG. 11
As shown in, the P ₁₁ point located the end point, the tool system 50 between a point situated below this point to the end point (the point from the point P ₁₂ to the point P ₁₆₎ moves linearly Sometimes tool system 5
It is determined whether or not 0 and the work system interfere with each other, and this determination result is stored in a predetermined area of the RAM 35 as a secondary connection point. In the example shown in FIG. 11, since the tool system in between the point P ₁₁ and the point P ₁₆ tool system 50 is moved linearly resulting in contact with the workpiece system, this case is determined to interfere You.

FIG. 12 shows a case where the points P ₁₁ , P ₁₂ , and P ₁₃ at which no interference occurs at the primary connection point are stored in the RAM 35 as described above. An example of a secondary connection point is shown. As shown in the figure,
For example, when focusing on the point P _11, the distance to the point P ₁₆ L
Interference between the tool system and the work system is generated in a section corresponding to _{11 and 16,} the distance to each point to the point P ₁₄ and the point P ₁₅ L
_It can be seen that no interference occurs in the sections corresponding to _L11,14 and _L11,16 , respectively.

The determination of the presence or absence of the interference between the two connection points and the storage of the determination result in the RAM 35 are repeatedly performed until there is no point on the end point side. As a result, the t-th order connection point (t = 1, t = 1) at which no interference between the tool system 50 and the work system occurs.
,... Are stored in the RAM 35, and thus the distances Ln, Ln, m,.
2,..., M = n + 1, n + 2,.
5 will be stored.

Finally, the distance L stored in the RAM 35
Ln + Ln, m +... based on n, Ln, m.
Extract one or a plurality of two connection points that minimize the value of.
In continuous section leading to the starting point P _{s (1)} point P ₁₆ from shown in FIG. 9,
Origin P _{s (1)} and the point P ₁₁ as second connection point, the point P ₁₁ and the point P _15,
Point P ₁₅ and the point P _16, 3 sets of 2 connecting points are extracted.

[0048] Similarly, to extract the second connection point also continuous section of the air-cutting tool path other than a continuous section from the point P ₁₆ from the starting point P _{s (1).} As a result, as shown in FIG. 11, for a continuous period of the air-cutting tool path other than a continuous section from the point P ₁₆ from the starting point P _{s (1),} respectively, the point P _{s (2)} and the point P _{e (2)} , Point P
_{s (3)} and point _{Pe (3)} , point Ps ₍₄₎ and point _{Pe (4)} , point Ps ₍₅₎ and point P
_{e (5)} , point Ps ₍₆₎ and point _{Pe (6)} , and point Ps ₍₇₎ and point _{Pe (7)} are extracted as two connection points.

In the next step 108 (see FIG. 3), the data indicating the tool path contained in the control point data 36 is
The point located between the two connection points in each empty cutting tool path extracted in step 106 is deleted, and a speed command code Fmax indicating a speed higher than the tool moving speed in the actual cutting tool path is inserted therebetween. Thereby, a new tool path is generated, and the new control point data 38 including the new tool path is stored in a predetermined area of the RAM 35.

For example, when the data indicating the tool path included in the control point data 36 is as shown in FIG.
As shown in FIG. 14, the point between the two connection points Ps _(n) and _{Pe (n)} is deleted, and the speed between the two connection points Ps _(n) and _{Pe (n)} is reduced. The command code Fmax is inserted to generate a new tool path (corresponding to the final tool path of the present invention). When the tool path included in the control point data 36 is in the state shown in FIG. 8, the new tool path is in the state shown in FIG. That is, in the section from the point P ₁₆ from the starting point P _{s (1),} the tool system 50
Move in a linear and fast from the starting point P _{s (1)} to the point P _11,
Similarly after moving linearly and fast from point P ₁₁ to the point P _15, moves linearly and fast from point P ₁₅ to the point P _16.

The process of step 100 corresponds to the information acquiring process of the present invention, the process of step 102 corresponds to the removal shape deriving process of the present invention, the process of step 104 corresponds to the empty cutting tool path determining process of the present invention, and the process of step 106. Corresponds to a two connection point extracting step of the present invention, and the processing of step 108 corresponds to a tool path generating step of the present invention.

As described in detail above, in the tool path generation method for the processing machine according to the present embodiment, the empty cutting tool path is determined based on the removal shape, and the continuous section of the empty cutting tool path is One or more of the two or more two connection points at which no interference occurs between the tool system and the work system, and the sum of the distances between the two connection points from the start point to the end point in the continuous section is minimized Since a connection point is extracted and a path formed by the extracted one or a plurality of two connection points is generated as a final tool path, an empty cutting tool path can be reliably determined, It is possible to generate a tool path that can significantly reduce the machining time.

In this embodiment, the case where the present invention is applied to the case where the control point data is optimized in the processing machine controller has been described. However, the present invention is not limited to this. As shown in FIG.
It may be applied to a case where CL data is optimized in an AM system, and as shown in FIG.
The present invention can also be applied to a case where NC data is optimized in a form separated from the CAM system and the processing machine controller.

In the present embodiment, a point located between the extracted two connection points is deleted, and a speed command code Fmax indicating a speed higher than the tool moving speed in the actual cutting tool path is inserted between them. However, the present invention is not limited to this. For example, a configuration may be adopted in which only a point located between two extracted connection points is deleted and the speed command code Fmax is not inserted. Can also. In this case, although the effect of shortening the processing time is reduced as compared with the present embodiment, the optimization procedure can be simplified.

In this embodiment, the case where the tool path generating program is recorded in the ROM has been described. However, the present invention is not limited to this. For example, a hard disk, a floppy disk, a CD-R
The tool path generation program may be obtained by recording the program on an external recording medium such as an OM and reading the external recording medium. In this case, the external recording medium corresponds to the recording medium of the present invention.

[0056]

As described in detail above, according to the first and third aspects of the present invention, an empty cutting tool path is determined based on a removal shape, and a continuous section of the empty cutting tool path is determined. The one or more two or more connection points where no interference occurs between the tool system and the work system, and the sum of the distances between the two connection points from the start point to the end point in the continuous section is minimized. Since two connection points are extracted and a path formed by the extracted one or a plurality of the two connection points is generated as a final tool path, it is possible to reliably determine an empty cutting tool path. In addition, it is possible to generate a tool path that can move the idle cutting section by the shortest distance and greatly reduce the processing time.

According to the second aspect of the invention, the same effect as the first aspect of the invention can be obtained, and one or a plurality of extracted information indicating the final tool path can be obtained. Since the information for increasing the tool moving speed between the two connection points is added, it is possible to generate a tool path capable of further reducing the machining time.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a processing system according to an embodiment.

FIG. 2 is a side view showing a configuration of a tool system provided in the processing machine in FIG.

FIG. 3 is a flowchart illustrating a flow of a program executed when the processing machine controller according to the embodiment generates new control point data.

FIG. 4 is a perspective view showing an example of a state of a tool path and a workpiece (formed material).

FIG. 5 is a perspective view showing a workpiece shape before processing of the cast material shown in FIG. 4;

FIG. 6 is a perspective view showing a workpiece shape after processing of the cast material shown in FIG. 4;

FIG. 7 is a perspective view showing a removed shape of the cast material shown in FIG. 4;

FIG. 8 is a diagram provided for explanation of an empty cutting tool path determination process, and is a plan view showing states of an actual cutting tool path and an empty cutting tool path with respect to a removed shape;

FIG. 9 is a diagram provided for describing an extraction process of two connection points;
It is a top view which shows the extraction procedure of a primary connection point.

FIG. 10 is a diagram provided for describing an extraction process of two connection points, and is a schematic diagram illustrating an example of a primary connection point.

FIG. 11 is a diagram provided for describing an extraction process of two connection points, and is a plan view illustrating a procedure of extracting a secondary connection point.

FIG. 12 is a diagram provided for explanation of an extraction process of two connection points, and is a schematic diagram illustrating an example of second and t-th connection points.

FIG. 13 is a schematic diagram showing a specific example of a tool path (initial tool path) included in control point data.

FIG. 14 is a schematic diagram showing a specific example of a tool path (final tool path) included in new control point data.

FIG. 15 is a plan view showing an example of a state of a new tool path.

FIG. 16 is a perspective view illustrating a state of a tool path with respect to a removed shape according to the first embodiment;

FIG. 17 is a diagram provided for describing a problem of the related art, and is a perspective view showing a state of a tool path (actual cutting tool path and empty cutting tool path) with respect to a workpiece.

FIG. 18 is a block diagram illustrating a configuration example of a processing system different from FIG. 1 according to the present invention.

FIG. 19 is a block diagram showing a configuration example of still another processing system according to the present invention.

[Explanation of symbols]

 Reference Signs List 10 processing system 12 work 20 CAM system 22 NC data 30 processing machine controller 32 CPU 34 ROM (recording medium) 40 processing machine 50 tool system 52 spindle head 54 quill 56 holder 58 tool

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H269 AB05 AB19 BB05 BB08 EE01 GG08 NN16 QC06 QE04 QE05 QE07

Claims (3)

[Claims] An information acquisition step of acquiring information indicating an initial tool path and a workpiece shape before machining; and removing a workpiece shape after machining obtained from the workpiece shape before machining based on the initial tool path. By doing so, a removal shape derivation step of deriving a removal shape by machining, an empty cutting tool path determination step of determining an empty cutting tool path based on the removal shape, and a tool system in a continuous section of the empty cutting tool path. One or more two connection points at which no interference occurs with the work system, and the one or more two connection points at which the total distance between the two connection points from the start point to the end point in the continuous section is minimized Extracting two connection points, and a tool path generation step of generating a path formed by the extracted one or more two connection points as a final tool path. Tool path generation method in processing machines to symptoms. 2. The method according to claim 1, wherein the tool path generating step adds information for increasing a tool moving speed between the extracted one or a plurality of two connection points to information indicating the final tool path. The method according to claim 1, wherein 3. An information acquisition procedure for acquiring information indicating each of an initial tool path and a workpiece shape before machining, and removing a workpiece shape after machining obtained from the workpiece shape before machining based on the initial tool path. By this, a removal shape derivation procedure for deriving a removal shape by machining, an empty cutting tool path determination procedure for determining an empty cutting tool path based on the removal shape, and a tool system in a continuous section of the empty cutting tool path. One or more two connection points at which no interference occurs with the work system, and the one or more two connection points at which the total distance between the two connection points from the start point to the end point in the continuous section is minimized A two-connection point extraction procedure to be extracted; and a tool path generation procedure to generate a path formed by the extracted one or a plurality of two connection points as a final tool path. A computer-readable recording medium a tool path generating program to be executed.