JP3378445B2 - Numerical control device for 3D cutting machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a numerical controller for controlling a feed speed of a three-dimensional cutting machine in order to extend the life of the tool. 2. Description of the Related Art Conventionally, in a three-dimensional processing machine, a numerical controller for controlling a feed speed of a tool according to tool path data in order to reduce the influence of a load applied to the tool and extend the life of the tool. Some have. For example, JP-A-63
The numerical controller disclosed in Japanese Patent Application Publication No. 710-710 calculates a three-dimensional cutting direction line segment (dx, dy, dz) from the tool path data, and calculates the three-dimensional cutting direction line segment (dx, dy, dz) in the depth direction. Polarity value (dz)
Is divided by the composite value (dl) as a tool feed speed parameter, and the horizontal tool feed speed (Fh) and the vertical tool feed speed (Fv) given in advance are calculated using the tool feed speed parameter ( The tool feed speed (F ') to be actually operated is calculated by linear interpolation at t). If the polarity value (dz) in the depth direction is dz ≧ 0, the tool feed speed (Fh) in the horizontal direction is set as the tool feed speed (F) when actually operating. Here, the composite value (d
l) The tool feed speed parameter t and the tool feed speed (F ') can be obtained by the following formulas 1, 2 and 3. [Formula 1] [Formula 2] [Equation 3] The tool feed speed (F ′) obtained in this way becomes slow when the ratio of the vertical line component is large. As described above, the numerical controller considers the movement of the tool in the vertical direction, reduces the effect of the load on the tool, and extends the life of the tool. [0003] As shown in FIG. 6, when the tool 1 moves on an upwardly inclined surface in a state where the tool 1 moves while cutting the surface of the workpiece 2, cash on L ₁ scraping contact with the tool is larger than the cutting cash L ₁ when the tool 1 is moved plane. However, according to the numerical control device, when the tool performs cutting movement on a flat surface or an upwardly inclined surface, the horizontal tool feed speed (Fh) is set as the tool feed speed (F) in each case. For this reason, when the tool moves on the upwardly inclined surface, a considerable load is applied, and the life of the tool is not significantly extended. Further, as shown in FIG. 7, a line segment A that rises directly from the cutting region to the non-cutting region, a line segment B that extends in the horizontal direction from the non-cutting region, , A line segment D going horizontally through the cutting area,
F, H, a line segment E going up on the up slope in the cutting area and a line segment G going down on the down slope in the cutting area.
When the tool feed speed (F) applied to the line segments A to H is determined by the numerical controller in the tool path constituted by the following formulas, the horizontal tool feed speed (Fh) except for the line segments C and G is obtained. Becomes That is, the tool feed speeds of the line segments A and B, which should be able to be fed faster because the workpiece material is not cut, are the same as the tool feed speeds of the line segments D, F and H for cutting the workpiece material. I will. As described above, the numerical control device does not set an appropriate tool feed speed for each line segment. Further, in order to obtain the tool feed speed (F), as described above, an arithmetic process using the above three equations
In particular, since the arithmetic processing of Expression 1 using all the line segment components dx, dy, and dz is required, there is a problem that this arithmetic processing takes a lot of time. The present invention has been made in view of such circumstances, and an object of the present invention is to provide a simple tool feed speed suitable for a tool path for extending the life of a tool of a three-dimensional cutting machine. Another object of the present invention is to provide a numerical control device for a three-dimensional cutting machine that can be set at a high speed. The inventor of the present invention has conducted intensive studies on the load state in the feed state of the tool, and as a result,
It has been found that the state of load applied to the tool can be roughly determined only by the presence or absence of vertical movement of the tool relating to the material to be processed, and the present invention has been accomplished based on this finding. The numerical controller according to the present invention includes a cutting data storage section for storing Z coordinate value Z ₀ of the upper end of the workpiece and tool path data, and a suitable tool feed for each line segment of the tool path data. It comprises a speed control unit for forming speed data, and a cutting data output unit for outputting cutting data including the speed data. The speed control unit obtains a Z coordinate value Z _1, Z ₂ of the start and end points of each line segment in the tool path data stored in the cutting data storage unit, whether the displacement of the Z ₁ with respect to the Z _0, the Z ₀ the presence or absence of displacement of Z ₂ and determines whether the displacement of Z ₂ with respect to Z _1, is aware of the feed state of the tool relative. That is, according to the above determination, the speed control unit determines that the cutting state is not established when Z ₂ > Z ₀ , the cutting state is established when Z ₁ > Z ₀ , and the Z ₁ = Z
_In the case of ₂ , there is no Z displacement, in the case of Z ₁ ≠ Z ₂ , Z
It recognizes that there is displacement. Therefore, the speed control unit:
The relationship between the tool feed speed in each state is that the speed in the non-cutting state> Z
Tool feed speed data is formed so that the speed in the state without displacement> the speed in the state with Z displacement> the speed in the cutting state. Referring to FIG. 7, the speed control section includes a Z
₂ > Z ₀ , non-cutting state like line segment A, B, Z
_{When 1} > Z _0, the cutting state like a line segment C, Z ₁ =
In the case of Z ₂ , it is recognized that there is no Z displacement such as line segments D, F, and H, and when Z ₁ ≠ Z ₂ , it is recognized that there is a Z displacement state such as line segments E and G. Suitable tool feed speed data is formed. For example, the line segment E having the upward inclination and the line segment G having the downward inclination have the same speed, and the tool feed speeds of the line segments A and B in the non-cutting state are the same as those of the line segments D, F and H in the state without Z displacement. It becomes larger than the feed speed. It should be noted that the tool feed speed can be formed simply by comparing the Z coordinate values, and does not require complicated arithmetic processing. Next, the present invention will be described with reference to the drawings. FIG. 1 is a system configuration diagram showing a specific example of the present invention. In FIG. 1, 3 is an XY table 4
This is a three-dimensional cutting machine capable of processing a workpiece 5 fixed thereon by a vertically movable spindle 6. Reference numeral 7 denotes a Z-coordinate value Z ₀ of the upper end of the workpiece 5 fixed to the three-dimensional processing machine 3, a tool path data, a speed setting value table in which speed setting values corresponding to speed parameters are previously stored, and the like. A cutting data storage unit. 8 sets a speed parameter for each line segment of the tool path data stored in the cutting data storage unit 1, and sets a speed set value corresponding to the speed parameter on the speed set value table to the tool feed speed data for each line segment. The speed control unit is formed as
Reference numeral 9 denotes a cutting data output unit that outputs cutting data including the tool feed speed data formed by the speed control unit 8 to the three-dimensional cutting machine 3. The speed control section 8 comprises a CPU and a ROM. The ROM stores the tool feed speed data for each line segment of the tool path data as shown in the flowchart of FIG. A program is stored. The CPU forms tool feed speed data for the tool path data based on the program. The procedure for forming the tool feed speed by the CPU with respect to the tool path data S stored in the cutting data storage unit will now be described with reference to the flowchart of FIG. First, in step 1, _i of each line segment Si constituting the tool path data S is set to 1. In step 2, the Z coordinate value of the start point of the line segment S _i Z _1, sets the Z coordinate value of the end point of the line segment S _i and Z _2. Next, in step 3, Z-coordinate value Z ₂ of the end point of the line segment S _i and judges whether or not the Z coordinate Z ₀ is greater than the upper end of the work piece. The determination result is recognized as Z _2> in the case of Z ₀ is the tool feed state of the line segment S _i in step 4 is a non-cutting state, to set the speed parameter V _i with respect to the line segment S _i. Here, employing the value of the speed setting value table as the tool feed speed Vcurr line segment S _i corresponding to the velocity parameter V _i. Then go to step 10. The result of the determination in step 3 is Z ₂ > Z ₀
In step 5, if not, Z coordinate value Z ₁ of the starting point of the line segment S _i and judges whether or not the Z coordinate Z ₀ is greater than the upper end of the work piece. The judgment result is in the case of Z _1> Z ₀ tool feed state of the line segment S _i is recognized as the cut state in step 6, set the speed parameter V ₂ with respect to the line segment S _i. Here, employing the value of the speed setting value table as the tool feed speed Vcurr line segment S _i corresponding to the velocity parameter V _2. Then step 10
Proceed to. Further, the result of the determination in step 5 is Z ₁ > Z ₀
In step 7, if not, Z coordinate value Z ₁ of the starting point of the line segment S _i and judges whether or not the same as the Z coordinate value Z ₂ of the end point of the line segment S _i. The determination result is Z ₁ = in step 8 in the case of Z ₂ is the tool feed state of the line segment S _i Z
Recognizes that it is displaced without state, to set the speed parameter V ₃ for this segment S _i. Here, employing the value of the speed setting value table as the tool feed speed Vcurr line segment S _i corresponding to the velocity parameter V _3. Then go to step 10. The result of the determination in step 7 is Z ₁ = Z ₂
If not the tool feed state of the line segment S _i is recognized as a state there Z displacement in step 9, to set the speed parameter V ₄ with respect to the line segment S _i. Here, the line segment S
_The above speed parameter V _{4 is} used as the tool feed speed Vcurr of _i.
Is formed on the speed setting value table corresponding to. Then go to step 10. In step 10, 1 is added to the above-mentioned i, and set as i. That is, S _{i + 1} is defined as S _i . Subsequently, in step 11, the newly set i is n
It is determined whether it is greater than. Determines that the determination result is the i> n is the formation of the tool feed speed data in each segment S _i all tool path data S, this program is ended. If the result of the determination in step 11 is not i> n, the line segment S _i for which the tool feed speed data has not been formed yet.
It is determined that there is, the flow returns to step 2 to form the tool feed speed data of the line segment S _i. The cutting data storage unit 7 stores
As shown in FIG. 3, four speed setting value tables are provided in consideration of the material of the work material and the type of tool. In addition, these speed setting value tables can be increased or decreased by operating means (not shown),
Further, the values on the speed setting value table can be changed. Further, the Z coordinate Z ₀ of the upper end of the work material stored in the data storage unit 7 can also be set from the operation means or the like. In addition,
When a plurality of speed setting value tables exist in the cutting data storage unit 7, before the program is executed,
One speed setting value table is selected by the operation means or the like. The setting of values on the speed setting value table will be described with reference to FIG. By executing the above program, each line segment is divided into four states: a non-cutting state, a cutting state, a state without Z displacement, and a state with Z displacement. When examining the relationship between these four states and the load applied to the tool, the load applied to the tool is:
No displacement state> The relationship with the non-cutting state is approximately established. Therefore, the values on the speed setting value table are set so that the relationship between the tool feed speed in each state is as follows: speed in the non-cutting state> speed in the state without Z displacement> speed in the state with Z displacement> speed in the cutting state. Have been. Naturally, the values on the speed setting value table take into account the load applied to the tool, and are values obtained in consideration of each cutting condition and the like. For example, as shown in FIG. 5 (a), when cutting the ABS resin 10 which is the material to be processed by the R3.0 ball end mill using the cutting data including the tool path data S, each line of the tool path data S by the execution of the program to the minute S _n, so that the tool feed speed data as shown in FIG. 5 (b) is formed. In this case, the speed setting value table shown in FIG. 3A is selected in advance. In the case where one type of workpiece is always processed, the type of tool is not changed, and the cut shape is almost the same, the speed setting value table is not necessary, and the program is not required. What is necessary is just to write the tool feed speed of each state above. In particular, when a smooth and spot-free surface processing is required, a program for setting the tool feed speed in the state with the Z displacement can be prepared separately. Examples of the program include a program that determines the feed speed of the tool in accordance with the moving angle of the tool and a program that determines the feed speed of the tool in accordance with the maximum cutting depth of the tool. However, when these programs are executed, the arithmetic processing takes a lot of time, so use it only when really necessary.
It is necessary to be able to select by operating means. In the above specific example, the speed setting value table is created in consideration of the material of the work material and the type of tool. However, the speed setting table is considered in consideration of various factors such as the number of rotations of the tool and the processing shape. May be created. The present invention is embodied in the form described above, and has the following effects. The numerical controller according to the present invention simply compares only the Z coordinate value of each line segment of the tool path data, and determines whether the tool feed state of each line segment is a non-cutting state, a cutting state, a state without Z displacement, and a state without Z displacement. Recognizing whether any of the states with displacement, the relationship between the tool feed speed in each state, the speed in the non-cutting state> speed in the state without Z displacement> speed in the state with Z displacement>
The tool feed speed is formed so as to be the speed in the cutting state. Thus, when the load on the tool is large, the speed is low, and when the load on the tool is small, the speed is high, and the effect of the load on the tool is reduced. Further, the numerical control device of the present invention has a simple configuration, and therefore can be easily realized and is substantially useful. Further, since a complicated arithmetic processing is not required to form the above-mentioned tool feed speed, it operates at a very high speed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a system configuration diagram showing a numerical controller according to a specific example of the present invention. FIG. 2 is a flowchart showing a tool feed speed data generation processing program of the numerical controller of FIG. 1; FIG. 3 is a speed setting value table stored in a cutting data storage unit of the numerical controller of FIG. 1; FIG. 4 is an explanatory diagram illustrating a load applied to a tool and a tool feed speed in a tool feed state. FIG. 5 is an explanatory diagram illustrating a tool feed speed of tool path data S; FIG. 6 is an explanatory diagram illustrating a load applied to a tool in a tool feeding state. FIG. 7 is an explanatory diagram illustrating an example of each line segment of tool path data. [EXPLANATION OF SYMBOLS] 3 3-dimensional cutting machine base 7 Cutting data storage unit 8 Speed controller 9 Cutting data output unit 10 the processed material S toolpath S _i line Z ₀ Z coordinates Z ₁ of the upper end of the material to be processed Z-coordinate of the end point of the start point of the Z coordinate Z ₂ S _i of S _i

Claims (1)

(1) A numerical control device for controlling a tool feed speed of a three-dimensional cutting machine, wherein a Z coordinate value of an upper end of a workpiece fixed to the three-dimensional cutting machine is provided. A cutting data storage unit that stores Z0, tool path data, and a speed set value table, and Z coordinate values Z1, Z2 of the start and end points of each line segment in the tool path data stored in the storage unit are obtained. In the non-cutting state when Z2> Z0, and Z1> Z
When 0, the cutting state is recognized, when Z1 = Z2, there is no Z displacement state, and when Z1 ≠ Z2, the Z displacement state is recognized. A speed control unit that forms tool feed speed data so that the speed in the absence state> the speed in the state with Z displacement> the speed in the infeed state, and cutting data including the tool feed speed data formed by the speed control unit And a cutting data output unit for outputting to the three-dimensional cutting machine.