JP2016151825A - Operation control method of combined machining lathe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an operation control method of a combined machining lathe capable of preventing deterioration of a quality of the processing surface and the shortening of the life of a tool by avoiding the processing performed at a tip end (peripheral speed zero point at the processing time) of the tool (ball end mill) when the processing is performed based on a processing program obtained by converting NC data as a development figure in a CMA (combined machining lathe) into a cylindrical coordinate system.SOLUTION: A operation control method of a combined machining lathe includes: a first processing program preparation step of preparing a first processing program based on NC data by developing a shape of a final object to be processed into a planar shape; a second processing program preparation step of preparing a second processing program by adding a coordinate turning command to the command related to a processing output point in the first processing program prepared by the CAM means; and a step of calculating a command value of the processing point after being converted into coordinates by analyzing the second processing program.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an operation control method for controlling the operation of a composite machining lathe having three translation axes, a workpiece rotation axis, and a tool rotation axis.

  When processing complex three-dimensional shapes using a multi-tasking lathe (for example, forming threads on a cylindrical surface, etc.), milling should be the main process, and the ball end mill should be used for finishing. There are many. When machining such a complicated three-dimensional shape, a machining program is created using CAM (Computer Aided Manufacturing) data, and the operation of the complex machining lathe can be controlled by the machining program. Many.

  In addition, when creating a machining program using CAM data in this way, NC data obtained by developing the final workpiece (work) shape into a planar shape using the CAM function. Is converted into a cylindrical coordinate system (so-called so-called, a developed view of the shape of the final workpiece is wound around a cylinder) (Patent Document 1). That is, in CAM, NC data as a development view is moved around the x-axis (translation axis), z-axis (translation axis) direction (translation) and c-axis (workpiece rotation axis) in a complex machining lathe to be actually machined. A program is created by converting it so that it can be processed into a workpiece by rotating it. By using such a method, even a machining program for complicated machining can be created relatively easily without requiring a 3D solid model of the entire workpiece.

JP 2004-21474 A

  However, since the machining program obtained by converting NC data in the CAM as described above is created based on the development view, a tool (ball end mill) is provided at a portion such as a groove bottom that becomes a flat portion on the development view. Machining will be performed at the tip (peripheral speed zero point portion at the time of machining). Therefore, the quality of the machined surface is deteriorated and the tool life is shortened.

  An object of the present invention is based on a machining program obtained by solving the problems of the operation control method in the conventional combined machining lathe and converting NC data as a development view into a cylindrical coordinate system in the CAM as described above. When machining, it is possible to avoid machining at the tip of the ball end mill (peripheral speed zero point part during machining) and prevent deterioration of the machined surface quality and shortening of the tool life. An object of the present invention is to provide an operation control method for a machining lathe.

  Among the present inventions, the invention described in claim 1 is an operation control method for controlling the operation content of a composite machining lathe having three translation axes, a workpiece rotation axis, and a tool rotation axis. A first machining program creation step for creating a first machining program based on NC data obtained by expanding the shape of a typical workpiece into a planar shape, and coordinates in a command relating to a machining output point in the created first machining program A second machining program creation step of creating a second machining program by adding a turning command; and a step of calculating a command value of a machining point after coordinate conversion by analyzing the second machining program It is characterized by this.

  The invention described in claim 2 is the invention described in claim 1, wherein the first machining program creation step creates the first machining program by converting the NC data into a cylindrical coordinate system. It is characterized by being.

  According to the operation control method of the first aspect, when machining is performed based on a machining program obtained by converting NC data as a development view into a cylindrical coordinate system in the CAM, the tip of the ball end mill (at the time of machining) Since machining at the peripheral speed zero point portion is avoided, the quality of the machined surface can be improved and the tool life can be extended. Also, even if you do not use expensive 5-axis CAM software that allows you to set the tool angle, you can use inexpensive 3-axis CAM software to make the quality of the machined surface of 3D shapes of complex cylindrical surfaces. Can be improved.

  In the operation control method according to claim 2, the first machining program creation step creates the first machining program by converting the NC data into the cylindrical coordinate system. It is possible to shorten the operation time by creating it inside, and operation errors are less likely to occur.

It is explanatory drawing (perspective view) which shows a composite processing lathe. It is a block diagram which shows the control mechanism of a multi-tasking lathe. It is explanatory drawing which shows the state processed into a workpiece | work with a tool (ball end mill) in a peripheral speed zero point part (b is an enlarged view of the circle A part in a). It is explanatory drawing which shows the method of coordinate-converting a process point. It is a flowchart which shows the processing content at the time of creating a 2nd machining program from a 1st machining program. It is explanatory drawing which shows the state processed into a workpiece | work with a tool (ball end mill) in the processing point after coordinate transformation (b is an enlarged view of the circle B part in a).

Hereinafter, an embodiment of an operation control method for a combined machining lathe according to the present invention will be described in detail with reference to the drawings.
<Composition of compound processing lathe>
FIG. 1 is an explanatory view showing a combined machining lathe equipped with a control device according to the present invention. In the combined machining lathe 1, a support base (not shown) is installed on the bed 2 so as to be slidable in the horizontal z-axis direction (left-right direction). Further, a slide table (not shown) is installed on the support table so as to be slidable in the y-axis direction (front-rear direction) perpendicular to the z-axis. Further, an elevating table (not shown) is installed on the front surface of the slide table so as to be slidable in the x-axis direction (vertical direction) perpendicular to the y-axis and the z-axis. A tool table 3 for holding a tool is installed on the front surface of the lifting platform (that is, the tool table 3 is installed on the bed 2 so as to be able to translate in the z, y, and x directions). ) Further, the head 2 and the tailstock 5 are installed on the bed 2, and the work W, which is a workpiece, is supported so as to be rotatable around a c-axis parallel to the z-axis.

<Control mechanism of complex machining lathe>
On the other hand, FIG. 2 is a block diagram showing a control mechanism (NC control device) for controlling the operation of the composite lathe 1 described above. The control device main body 12 of the NC control device 11 includes a support base and a slide base. Servo motors 16 to 18 for translating the elevator and a servo motor 19 for rotating the main shaft (c-axis) are connected via an interface 15. Further, an input means 21 for inputting machining conditions and the like, an output means 22 for outputting the inputted machining conditions and the like are connected to the control device main body 12 via an interface 15. Further, CAM means 20 for creating a machining program is connected to the control device main body 12 via an interface 15. In addition, the control device main body 12 is provided with a CPU 13 and storage means 14, and a program storage area for storing various machining programs and the like is provided in the storage means 14.

<Operation details of the combined lathe>
The combined machining lathe 1 configured as described above translates a support base, a slide base, and a lift base by servo motors 16 to 18 to convert a tool T (ball end mill) of the tool base 3 installed on the lift base into c The workpiece W is processed by being brought into contact with the workpiece W rotating around the axis. Further, the NC control device 11 controls the translation of the support table, slide table and lift table by the servo motors 16 to 18 and the rotation of the workpiece W around the c-axis.

  In the combined machining lathe 1, a program for complex three-dimensional machining (for example, machining for forming a screw thread on a cylindrical surface) can be created using the CAM means 20. As described above, when a machining program having a three-dimensional shape is created using the CAM means 20, a final development view of the shape of the workpiece W (after machining) is obtained by using the function of the CAM means 20. Created by wrapping around a cylinder (calculated).

  That is, in the CAM means 20, machining is performed by converting NC data as a development view so that the workpiece can be machined by translation in the x-axis and z-axis directions and rotation around the c-axis in the complex machining lathe 1 to be actually machined. Create a program (first machining program). As such a method, NC data expanded into a flat plate shape is converted into a cylindrical coordinate system by NC rotary conversion (for example, a line segment having a length L is converted into a circle having a diameter of L / 2π, and this line is converted. A method of mapping two points having a distance x on the minute L to two points on the circumference having an angle of 2πx / L with respect to the center of the circle can be suitably used (see Patent Document 1).

  When the bottom surface on the development view is machined by the function of the CAM means 20 as described above, the peripheral speed of the contact point between the tool T (pole end mill) and the workpiece W becomes a zero point. That is, the machining output point in the first machining program is on the x-axis on the xy plane of the composite machining lathe 1 as shown in FIG. 3, and the tool T does not move in the y-axis direction, and the xz-c axis. In this case, the cylindrical surface is processed. In machining in such a state, since the peripheral speed is not generated in the tool T at the time of bottom machining, the machining surface becomes a so-called “peeling state”, the machining surface quality is deteriorated, and the tool life is shortened. Become.

  Therefore, in the NC control device 11 of the combined machining lathe 1, the machining points in the first machining program are coordinate-transformed to translate and rotate the machining points. That is, a command for setting an arbitrary angle and rotating the coordinates of the machining point on the xy plane is created (see FIG. 4). Then, by adding the command to the machining program, the first machining program is modified to create a second machining program. Then, the workpiece W is machined using the modified second machining program.

  FIG. 5 is a flowchart showing the processing contents in the NC control device 11 when the first machining program is modified to create the second machining program. When processing a complex three-dimensional shape (for example, processing for forming a screw thread on a cylindrical surface, etc.) in the composite working lathe 1, first, in step (hereinafter simply indicated by S) 1, CAM means 20 The first machining program is created using At that time, a machining trajectory synchronized with the rotation of the c-axis is created by using the “function for creating a machining program by winding a developed view of the final shape of the work W around the cylinder” of the CAM means 20.

  After that, in S2, by using the input means 21 to input the dimensions of the tool T (ball end mill), the output command point in the first machining program created in S1 is the center of the tool T (ball center). The first machining program is rewritten so that

  Next, in S3, the first machining program rewritten as described above is transferred to the control device body 12. After that, in S4, based on the numerical value input by the input means 21, a predetermined turning angle for coordinate transformation of the machining point is determined on the xy plane. In S5, the second machining program is created by modifying the first machining program by adding the determined turning angle and the coordinate turning command at the turning angle to the first machining program rewritten in S2. To do.

 As described above, after the second machining program is created, the combined machining lathe 1 is activated in S6, and in S7, the controller main body 12 analyzes the second machining program, as shown in FIG. A command value of the machining point of the tool T after the coordinate conversion is calculated. In step S8, the workpiece W is machined with the calculated machining point command value.

  Since the NC control device 11 internally converts the program command value and generates a command in a new coordinate system as described above, the machining point of the tool T is changed. Therefore, the contact position of the tool T (ball end mill) with the workpiece W can be avoided from the peripheral speed zero point as shown in FIG. When the above-described operation control method is used, if the machining output point is the tip of the tool T (ball end mill), a shape error occurs in machining after coordinate rotation movement. It is necessary to keep the mind as the output point.

<Effects of operation control method for combined machining lathe>
As described above, the operation control method of the combined machining lathe 1 by the NC control device 11 is the first machining for creating the first machining program based on the NC data obtained by developing the final workpiece shape into a planar shape. Program creation step (S1, S2) and second machining program creation step (S4, S5) for creating a second machining program by adding a coordinate turning command to a command relating to the machining output point in the created first machining program And a step (S7) of calculating a command value of the machining point after coordinate conversion by analyzing the second machining program. Therefore, according to this operation control method, when machining is performed based on the second machining program, machining at the tip of the tool T (ball end mill) (peripheral speed zero point portion during machining) is avoided. Is done. Therefore, according to this operation control method, the quality of the machined surface can be improved and the tool life can be extended. Also, without using expensive 5-axis CAM software that allows you to set the tool angle, you can use inexpensive 3-axis CAM software to improve the quality of the machined surface when machining complex cylindrical surfaces. Can be improved.

  Moreover, since the first machining program creation step (S1, S2) creates the first machining program by converting the NC data into the cylindrical coordinate system, the operation control method by the NC control device 11 is the first. A machining program can be created within a short time to shorten the operation time, and operation errors are less likely to occur.

<Example of change of operation control method for combined machining lathe>
The operation control method of the combined machining lathe according to the present invention is not limited to the aspect of the above embodiment, and the configuration of the first machining program creation step, the second machining program creation step, etc. Changes can be made as necessary within a range that does not deviate. In addition, the configuration of the combined machining lathe to be controlled is not limited to the aspect of the above-described embodiment, and the configurations of the bed, the support base, the slide base, the lifting base, the tool base, the spindle, and the like are set as necessary. It can be changed as appropriate.

  For example, the operation control method is not limited to the creation of the second machining program from the first machining program as in the above embodiment, but the creation of the second machining program in the CAM means (ie, It is also possible to change to the one that performs the correction of the first machining program. Further, the operation control method according to the present invention is limited to a method in which the tool translates along the x, y, and z axes and uses the c axis along the z axis as a workpiece rotation axis as in the above embodiment. Instead, it may have a different shaft configuration.

1 ・ ・ Multi-function lathe 2 ・ ・ Bed 3 ・ ・ Tool headstock 4 ・ ・ Main shaft 5 ・ ・ Tailstock 11 ・ ・ NC control device 12 ・ ・ Control device body 20 ・ ・ CAM means

Claims (2)

An operation control method for controlling the operation content of a combined machining lathe having three translation axes, a workpiece rotation axis, and a tool rotation axis,
A first machining program creation step for creating a first machining program based on NC data obtained by developing the final workpiece shape into a planar shape;
The second machining program creation step for creating a second machining program by adding a coordinate turning command to the command related to the machining output point in the created first machining program, and the coordinate conversion is performed by analyzing the second machining program. And a step of calculating a command value of the machining point after machining.   2. The operation control method for a composite machining lathe according to claim 1, wherein the first machining program creation step creates the first machining program by converting the NC data into a cylindrical coordinate system.

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