JP2000099122A - Maximum non-interacting rotator determination device for CAM system - Google Patents

Abstract

(57) [Problem] To provide a combination of a shape of a tool holder and a tool protrusion length, which can always be reliably and optimally set for securing tool support rigidity. SOLUTION: An interference inspection model creating means 1 for cutting a three-dimensional model representing a product shape at a predetermined pitch in a center axis direction of a cutting tool to create a step-like interference inspection model from a contour shape of each cut surface, and a material. A center axis of the cutting tool and each stage of the interference inspection model at a plurality of points on the tool path based on a tool path for moving a cutting tool having a predetermined outer diameter so as to machine the product into the product shape and the interference inspection model. The maximum non-interacting rotation to obtain the maximum non-interacting rotator by obtaining the maximum shape of the rotator that does not interfere with the interference inspection model from the shortest distance to the above, and obtaining the minimum shape among the obtained maximum rotator shapes at a plurality of points And a body shape creating means 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CAM (Computer Aided Machining) system which uses a maximum non-interacting rotator to determine tool conditions for creating NC data for an NC (Numerical Control) machining apparatus. It relates to a decision device.

[0002]

2. Description of the Related Art When machining the shape of a product such as a mold in a CAM system, the rigidity of a cutting tool and a tool holder is secured while avoiding interference between a material to be processed and the tool holder. It is necessary to set the tool conditions so as to achieve high-speed and high-precision machining (improvement of machining quality). Therefore, conventionally, as shown in FIG.
TH shape, mold shape model DM, and tool path CP for moving a tool with a predetermined tool diameter to cut out the mold shape
(One point is shown in the figure) to the CAM system, and the interference calculation between the tool holder TH moving along the tool path CP and the mold shape model DM is performed, thereby obtaining the tool holder TH. Has caused the CAM system to automatically determine the tool protrusion length L that does not interfere with the mold shape model DM.

[0003]

However, in such a conventional method, since the shape of the tool holder TH is set in advance, the shape of the tool holder TH and the tool protrusion length L are set.
There is a problem that the combination with the above is not always optimal for securing the rigidity of the cutting tool and the tool holder.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus which advantageously solves the above-mentioned problems, and a method of determining a maximum non-interacting rotator for a CAM system according to the present invention. As shown in FIG. 1, the apparatus cuts a three-dimensional model representing a product shape at a predetermined pitch in a central axis direction of a cutting tool and creates a step-like interference inspection model from a contour shape of each cut surface. An interference inspection model creating means 1 and a center of the cutting tool at a plurality of points on the tool path based on the interference inspection model and a tool path for moving a cutting tool having a predetermined outer diameter so as to process a material into the product shape. From the shortest distance between the axis and each stage of the interference inspection model, a maximum rotating body shape that does not interfere with the interference inspection model is obtained, and a minimum shape among the obtained maximum rotating body shapes at a plurality of points is obtained. The maximum non-interfering rotating body shape creating means 2 for creating a non-interfering rotating body, is made of comprises a.

In such an apparatus, the interference inspection model creating means 1 cuts the three-dimensional model representing the product shape at a predetermined pitch in the direction of the center axis of the cutting tool and obtains a step-like interference from the contour shape of each cut surface. An inspection model is created, and the maximum non-interfering rotating body shape creating means 2 is arranged on the tool path based on the tool path for moving a cutting tool having a predetermined outer diameter so as to process a material into the product shape and the interference inspection model. From the shortest distance between the center axis of the cutting tool and each stage of the interference inspection model at a plurality of points, a maximum rotating body shape that does not interfere with the interference inspection model is determined. Find the minimum shape and create the largest non-interacting rotator.

Accordingly, the largest non-interacting rotator created by this apparatus has the largest shape among the rotator shapes that can move along the entire tool path without interfering with the interference inspection model and thus the product shape three-dimensional model. The combination of the shape of the tool holder and the protrusion length of the tool can be prevented regardless of the combination of the shape of the tool holder and the protrusion length of the tool within the range included in the maximum non-interference rotating body. Can always be set optimally for ensuring the rigidity (tool supporting rigidity) of the cutting tool and the tool holder.

[0007] In the apparatus of the present invention, the predetermined pitch may be equal to the tolerance for interference inspection, and in this case, the size of the largest non-interacting rotator can be reliably set within the tolerance range. Can be stored inside.

Further, in the apparatus of the present invention, the plurality of points may include at least the constituent points of the tool path. In this case, the maximum rotation is at least at the position of the constituent point of the tool path. Since the body shape can be obtained, the maximum non-interacting rotator can be created with higher accuracy.

[0009]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 2 is a block diagram showing an embodiment of the maximum non-interacting rotator determining apparatus for a CAM system according to the present invention. The apparatus according to this embodiment converts a mold material having particularly high strength into a mold shape. It is used to create NC data for processing, and can be specifically configured by appropriately modifying an operation program of a computer constituting a normal CAM system.

That is, as shown in FIG. 2, the apparatus according to the present embodiment performs a process shown in FIG. 3 on the basis of a mold shape model data 3 representing a mold three-dimensional shape as a product shape.
As shown in the figure, the mold shape model DM is cut at a predetermined pitch in the center axis direction of the cutting tool to create a step-like interference inspection model CM from the contour shape of each cut surface, and the data of the interference inspection model CM 4, an interference inspection model creating unit 5 serving as interference inspection model creating means 1, tool path data 6 for moving a cutting tool having a predetermined outer diameter so as to process a mold material into a mold shape, and the interference. 6A and 6B based on the inspection model data 4 and the processing shown in FIG.
As shown in the figure, from a minimum diameter MD having a radius of a shortest distance between the center axis CA of the cutting tool CT and each stage of the interference inspection model CM at a plurality of points on the tool path CP, indicated by a broken line in the drawing,
Determine the maximum rotating body shape MRBF that does not interfere with the interference inspection model, determine the minimum shape among the determined maximum rotating body shapes MRBF at multiple points, and create the maximum non-interfering rotating body shape,
A maximum non-interacting rotator shape creating unit 8 as the maximum non-interacting rotator shape creating means 2 for outputting the data 7 of the maximum non-interacting rotator shape is provided.

In the process shown in FIG. 3, the interference test model creating section 5 firstly performs step 11 as shown in FIG.
Z-axis direction of tool DM model coordinate system (tool axis direction)
The maximum value Zmax and the minimum value Zmin of
Then, from the maximum value Zmax and the minimum value Zmin and the interference inspection allowable error AP, the number n of steps for cutting the mold shape model DM so as to have a pitch substantially equal to the interference inspection allowable error AP
(N = 6 in the example of FIG. 4). Thereafter, steps 13 to 15 are repeated by the number of cutting steps n while increasing the steps one by one from the bottom.
Then, the cutting Z value of the step is determined, and a cutting plane perpendicular to the Z axis is created. In the following step 14, the mold shape model DM is cut at the cutting plane to create a contour line on the cutting plane. And
In a succeeding step 15, data such as the number of constituent points of the contour and the coordinates of each constituent point are stored in a file, and the contour management table indicating the number n of contours and the number of contours in each step is updated. And do. Through this process, the interference inspection model creation unit 5 can create a step-like interference inspection model CM including the mold shape model DM as shown in FIG.

After the interference inspection model creating section 5 creates the interference inspection model CM, the maximum non-interacting rotator shape creating section 8 first executes step 21 in the processing shown in FIG.
Then, a tool model (including the cutting tool and the tool holder, the radius of each step is a variable at this time) of the number of steps n equal to the number of cutting steps is set, and then the step
At 22, one point is read as the tool center point from the data of the tool path CP as shown in FIG. 6 (a), and the position of the component point of the tool path CP is read. It is determined whether or not there is, and if it is the end point, the process is terminated.

In step 24, it is determined whether or not the tool center point is the starting point of the tool path. If the starting point is the starting point, the subsequent steps 25 and 26 are skipped and the process proceeds to step 27. In step 25, the distance between the current tool center point and the tool center point read in the previous step 22 is calculated, and the distance between the interpolation points to be interpolated at a pitch substantially equal to the interference inspection tolerance AP is calculated. The number is determined, and in the following step 26, a tool center point is created by interpolating between the current tool center point and the previous tool center point.

Thereafter, steps 27 to 29
By repeating while moving the target point one by one by the number of tool center points including the interpolation point, first in step 27,
Interference inspection model where the tool center point as the target point is located
The number of CM stages (i) from the bottom is calculated (FIG. 6 (b)
Here, i = 1 because of the first step from the bottom). Thereafter, step 28 and step 29 are repeated the number (ni) corresponding to the corresponding step number.
In step 28, as shown in FIG. 6 (b), the object stage is repeated while raising the target stage one by one, and the contour at the target stage and the tool center axis CA are formed. The shortest distance is calculated on the cutting plane, and the shortest distance is doubled to obtain the minimum diameter MD.
Then, compare the minimum diameter MD of the corresponding step of the tool model with the previously obtained minimum diameter MD and replace the minimum value if it is smaller than the previous one, and replace the minimum value if it is equal to or larger than the previous one. In this case, the minimum value of the minimum diameter MD of the corresponding stage is updated.

Therefore, by repeating steps 28 and 29, the position above the step of the interference inspection model CM where the tool center point is located is the minimum diameter of each step of the tool model, and thus the maximum rotating body shape that does not interfere with the interference inspection model CM. The MRBF is obtained and it is repeated for the number of tool center points including the interpolation point from step 27.Therefore, the maximum rotating body shape for the position above the level of the interference inspection model CM where the tool center point is located between the two component points of the tool path MRBF is determined and the process is repeated from the start point to the end point of the tool path, that is, for each step of the tool model.Therefore, the minimum diameter of each step of the tool model is the smallest of the obtained maximum rotating body shapes MRBF, that is, the maximum Since it is a non-interacting rotator, the maximum non-interacting rotator shape creating unit 8 can create the maximum non-interacting rotator shape by such processing.

The maximum non-interacting rotary body shape created by the apparatus of the above embodiment is the largest shape that does not interfere with the mold shape at any position over the entire length of the tool path. Interference can be prevented no matter how the combination of the shape of the tool holder TH and the tool protrusion length L is set within the range included in the rotating body. Therefore, according to the apparatus of the above embodiment, the combination of the shape of the tool holder and the tool protrusion length can always be set optimally for ensuring the rigidity of the cutting tool and the tool holder.

Further, according to the apparatus of the above embodiment, the predetermined pitch between the respective stages is substantially equal to the interference inspection allowable error AP, so that the size of the largest non-interfering rotating body can be surely set to the allowable error AP. Can be set within the range.

Further, according to the apparatus of the above embodiment, the plurality of points for obtaining the shortest distance between the contour line of the interference inspection model CM and the tool center axis CA include at least the constituent points of the tool path CP. The maximum rotating body shape can be obtained at the position of the component point of the tool path, and the maximum non-interacting rotating body can be created with higher accuracy.

Although the present invention has been described with reference to the illustrated examples, the present invention is not limited to the above-described examples. For example, the above-described embodiment was applied to the creation of NC data for machining a die. The present invention can also be applied to the creation of the NC data for processing of the product described above, and the same effects as those of the above embodiment can be obtained.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a configuration of a maximum non-interacting rotator determining apparatus for a CAM system according to the present invention.

FIG. 2 is a configuration diagram showing an embodiment of a maximum non-interacting rotator determining apparatus for a CAM system according to the present invention.

FIG. 3 is a flowchart illustrating a process executed by an interference test model creation unit in the apparatus according to the embodiment.

FIG. 4 is an explanatory diagram showing a process executed by an interference test model creating unit in the apparatus of the embodiment.

FIG. 5 is a flowchart illustrating a process executed by a maximum non-interacting rotator shape creating unit in the apparatus according to the embodiment.

FIG. 6 is an explanatory diagram showing a process executed by a maximum non-interfering rotator shape creating unit in the apparatus of the embodiment.

FIG. 7 is an explanatory diagram showing a conventional method of setting tool conditions.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Interference inspection model creation means 2 Maximum non-interference rotating body shape creation means 3 Die shape model data 4 Interference inspection model data 5 Interference inspection model creation unit 6 Tool path data 7 Maximum non-interference rotating body shape data 8 Maximum non-interacting rotating body Shape creation unit AP interference inspection tolerance CA Tool center axis CC Tool center point CM Interference inspection model CP Tool path DM Mold shape model MRBF Maximum rotating body shape

Claims (3)

[Claims] 1. A three-dimensional model (DM) representing a product shape is cut at a predetermined pitch (AP) in the center axis direction of a cutting tool to create a step-like interference inspection model (CM) from the contour shape of each cut surface. A plurality of points on the tool path based on the interference inspection model and a tool path (CP) for moving a cutting tool having a predetermined outside diameter so as to process a material into the product shape. In (CC), a maximum rotating body shape (MRBF) that does not interfere with the interference inspection model is obtained from a shortest distance between the center axis (CA) of the cutting tool and each stage of the interference inspection model, A maximum non-interacting rotator determining apparatus for a CAM system, comprising: a maximum non-interacting rotator shape creating means (2) for obtaining a minimum non-interacting rotator from the maximum rotator shape to create a maximum non-interacting rotator. 2. The apparatus according to claim 1, wherein the predetermined pitch is equal to an interference test tolerance. 3. The maximum non-interacting rotator determination apparatus for a CAM system according to claim 1, wherein the plurality of points include at least constituent points of the tool path.