JPS598842B2 - Mold processing automation method using copying model - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mold processing automation method using a copying model.

Conventionally, in the field of mold processing, many molds have complex free-form surfaces, and most of these have been processed using copying machines with models.

However, this copying process requires processing before finishing, such as rough cutting from the material, fillet cutting to make the cut uniform, and semi-finishing.
These processes require a lot of know-how on processing technology, including setup work, and require skilled workers, and it is difficult to process them unless these skilled workers are attached, so copying machines are equivalent to manual machines. It has been received.
In addition, in the case of copy machining, even when cutting multiple pieces of the same workpiece, the same operations, such as setup work, rough machining, fillet machining, semi-finishing machining, and finishing machining, are performed individually. It had to be carried out by a skilled worker. Furthermore, finishing accuracy is also affected by various conditions during machining, such as changes in stylus inclination due to part shape and feed rate, thermal deformation of the machine due to long machining, and disturbances to the profiling servo due to vibration during cutting. However, there was a drawback that uniformity and high precision could not be guaranteed. Recently, NC processing has begun to be adopted as a means of compensating for the above-mentioned drawbacks.

The above NC processing requires NC data.

Incidentally, NC data is a general term for input media that contains information on the propulsion that is input to the NC device, and includes all of the many existing types such as paper tape, magnetic tape, magnetic drum, and magnetic disk. Used as including. Conventionally, the following two methods are generally known for creating the above NC data.

First, one is the automatic programming method shown in Figure 1. In this method, the part programmer finally determines the definition of the machining shape and the movement of the tool based on the machining drawing A, and then performs calculations. Program sheet B in NC language
The computer C automatically calculates the tool path, etc., creates NC data D, and uses the NC machine E to machine the workpiece F based on this NC data.

This method can produce simple shapes such as a combination of straight lines and circles at relatively low cost, but when creating NC data for complex free-form surfaces, it takes a lot of time to create a program sheet. In addition, it takes a lot of time to create the program, requires a specialized engineer with computer knowledge, and it is impossible to eliminate input errors such as mistakes in creating the program. It required a large computer system, was very expensive, and was often shunned by workers in the field.

Another conventional method is to measure the model G with a three-dimensional measuring device H, etc., and process the measured data with a computer C, as shown in Figure 2, to obtain NC data with the same trajectory as the model shape. There is a known method in which a work piece D is prepared and then a workpiece F is finished cut by an NC machine E.

In this case, most of the coordinate measuring instruments are operated manually and require skill to measure, and even when cutting the workpiece, rough machining is currently done manually using a separate general-purpose machine. . This invention was made in view of the above-mentioned drawbacks, and it is possible to easily trace a finished model at high speed and without any load using the same conventional copying machine tool, without using a computer at all. An object of the present invention is to provide a method for automating mold machining in which NC data for mold machining is created, and furthermore, the NC data can be used to perform mold NC cutting by the same machine.

More specifically, this invention reversely utilizes a conventional copying machine tool as a method for recognizing the shape of a free-form surface when machining a mold having a free-form surface using an NC device. .

In other words, conventional copying machine tools use a stylus to copy a model and machine a workpiece by giving the tool the same movement as the stylus, but the present invention does not allow the tool to machine the workpiece. , only the movement of the tool at that time is extracted, and this allows the shape of the model to be recognized.

In this way, information regarding the model shape can be automatically retrieved as a copying operation, completely eliminating the need for manual operations as in the case of a conventional three-dimensional measuring device. Since no actual machining is involved, it can be traced at high speed without any load, and highly accurate information can be obtained without interference from thermal deformation of the machine or vibrations during cutting. Also, since the stylus is a contact type, it produces a certain displacement when tracing, and if this displacement is corrected,
This allows for even more accurate information to be obtained. Then, the optimum trajectory of the tool is determined from the information regarding the type of machining, the shape, the shape of the material, etc., and the information regarding the above-mentioned model shape. Information other than the information regarding the model shape is input in advance as input data.

The overall configuration of the system of the present invention is as shown in FIG.
A three-dimensional displacement detector 3 of the stylus and a control device 4 having a built-in computer as a converter are added, and the pattern of the processed shape and the shape of the material are inputted to the control device 4 as input data 5. It is.

The control device 4 has the following three main functions. 1)
Data collection function from the model 2) NC data creation function to find the optimal tool trajectory 3) NC function to perform tapeless operation from the obtained NC data Figure 4 shows the data creation function in the control device 4. Data 10 is obtained by correcting the axis position 3 with the stylus displacement 9, and then the stylus diameter and the used tool diameter 11 are given to correct the data 12 so that the simultaneous two-axis cutter offset function of the NC function can be used. Next, interpolation accuracy 13 is given to obtain interpolation data 14 suitable for the interpolation accuracy, and then the remaining amount 1
5 is given and the remaining allowance is added to interpolated data 16, and this data is converted into NC data 17 according to each processing.

Figure 5 is a block diagram for rough machining when converting to NC data, in which information 18 such as area setting, tool diameter, pattern, etc. is added to interpolated data 16 including remaining allowance, and the optimum data for each machining is calculated. NC data 19 for rough machining area machining is created.

The NC data created by the control device 4 described above is
As shown in the figure, it is stored in a floppy disk sheet 6 with a large memory capacity, and by interacting with this floppy disk sheet, rough cutting is performed using the same machine without tape.
Machining, Finishing When performing NC processing, or when applying it to another NC machine, add a puncher and apply N to the paper tape T.
It is used to generate C data. The present invention will be described below with reference to a specific example shown in FIG. 6. Reference numeral 21 indicates a machine base, 22 a table, 23 a column, 24 a spindle head, and 25 a tracer. The tool 26 is not attached, and the material 2 is not mounted on the table 22.
The model 29 set on the table 22 by the stylus 28 of the tracer 25 without setting the model 7, that is, without any load, is traced at high speed in the same way as in the copying process.

The table 22 has two drive mechanisms (not shown), respectively, in the left-right direction of the paper in FIG. 6 (hereinafter referred to as the ), and the spindle head 24 is supported by the column 23 and is driven vertically (hereinafter referred to as the Z direction) on the table 22 via a drive mechanism (not shown). One leg is driven.

As is well known, the spindle head 24 and the tracer 25 are configured to be integrally moved in a tracing motion by a servo mechanism or the like.

The amount of movement of the table 22 in the X direction is detected by an X direction movement amount detector 30, and the amount of movement in the Y direction and Z direction is also detected by a Y direction movement amount detector 31 and a Z direction movement amount detector 32, respectively. They are detected respectively.

These detectors are composed of linear scales or other appropriate movement amount detectors.

The detected amount of each detector is sent as a digital amount to the control device 33 with a built-in computer, and when creating NC data, the amount of movement in each axis direction when tracing the model 29 with the stylus 28 of the tracer 25 is calculated. The data is sent in digital quantities every moment, and thereby the surface shape or outline shape of the model 29 is sent in as each position coordinate of the point group.

In this case, since the stylus 28 is in contact with the model 29 to perform a tracing operation, the stylus 28 is always moving with a certain displacement, and this displacement results in an error. Therefore, the stylus 28 is provided with a stylus displacement detector 34, which three-dimensionally decomposes and detects the stylus displacement, and sends this to the control device 33, which detects the stylus displacement in each axial direction of the machine. By synchronizing and correcting the momentary position coordinate values from 32 each time, the data is inputted as data from which errors due to stylus displacement have been removed. The data with the stylus displacement corrected as described above is obtained as data that is offset outward from the shape of the model 29 by the diameter of the tip of the stylus 28, and is assumed to be the same data as the shape of the model 29. The stylus you are using for
8 in the Fbl leg device 33 in advance and offset the data uniformly. Further, the diameter of the tool to be used is entered into the control device 33 in advance, and the above data is determined as a locus of movement by the tool. Since the above data is discontinuous data in the form of a point group as described above, appropriate linear interpolation is performed between each point in order to convert it into continuous data corresponding to the shape of the model 29.

In this case, the curve is approximated by connecting straight lines, and the interpolation accuracy is set in advance in the control device 33 so that the error caused by this approximation is within the allowed accuracy. Furthermore, the control device 33 stores material shape, machining shape pattern, machining reference point,
Information necessary for actual processing, such as the remaining amount, is input in advance.

The above material shape is input as each dimension value of X, Y, and Z.

In addition, the machining shape pattern specifies whether surface tracing machining or contour tracing machining is acceptable based on the material shape and the machining shape. It specifies whether to process the shape or to cut the inside to create a concave shape with the necessary contour. In this case, several types of simplified machining patterns are prepared and these are combined. It allows processing of complex shapes.

Therefore, the machining area is divided as appropriate, and the machining pattern and machining order for each divided area are specified. In the above, setting of the machining area is to set the start point and end point of the area as X, Y, and Z position coordinates from the machining reference point.

When the material shape, machining area, and machining pattern are given as described above, the control device 33 calculates the optimal trajectory of the tool according to the machining pattern from the material shape in the relevant machining area to the model 29. It is.

In this case, if the remaining allowance is given, the optimum trajectory of the tool is determined taking this remaining allowance into consideration. When the optimum trajectory of the tool is determined in the control device 33 as described above, this data is converted into NC data in the form of a complete format input to the NC device, stored on a floppy disk sheet, and stored. I'll let you.

Then, when actually processing, remove model 29,
The material 27 is set in a predetermined position and subjected to NC processing.

As explained above, this invention adds a control device with a built-in computer to a copying machine tool, and traces a model using a stylus of a tracer with no load on the spindle side. The amount of movement is input into a computer moment by moment, and the data is analyzed. The NC system recognizes the shape of the model, determines the optimal tool trajectory from the material to the model-shaped workpiece according to the machining shape pattern registered in advance on the computer, and the material shape, and enables the machining. By creating the data, NC data for mold machining with complex free-form surfaces can be automatically created with high precision without requiring difficult computer knowledge. Moreover, the creation of NC data and the NC control can be performed on the same machine. Since it can be executed on the same computer, only half the equipment is required and costs can be reduced.

Furthermore, NC data for rough cutting can be created from the finished model, and the number of machining tools can be greatly reduced.

In addition, by adding a computer, it is possible to input various data, incorporate the know-how of field workers, and create highly accurate NC data. Records can be saved and used multiple times to process the same part, and even if the shape of a part is partially changed, a new mold can be created by editing past NC data without creating a model. It has various characteristics such as being able to process.

[Brief explanation of drawings]

Figures 1 and 2 are explanatory diagrams of the conventional NC data creation method, Figure 3 is a configuration diagram of the system of the present invention, and Figure 4 explains the NC data creation function for determining the optimal tool trajectory in the system of the present invention. FIG. 5 is a block diagram showing the function of creating NC data for rough machining area machining in the system of the present invention, and FIG. 6 is a schematic diagram showing the specific configuration of the present invention. 1... Copying machine, 2... Actual travel amount detector for each axis, 3... Three-dimensional displacement detector of stylus,
4... Control device, 5... Input data, 24... Spindle head, 25... Tracer, 26... Tool, 27 ...Material, 28...Stylus, 29...Model, 30...X-direction movement amount detector, 31...
. . . Y direction movement amount detector, 32 . . . Z direction movement amount detector, 33 . . . Control device.

Claims (1)

[Claims] 1. A three-dimensional copying machine is used that has a stylus for copying a model and has a servo system that determines the direction of movement according to the displacement of the stylus. In this case, each axis of the copying machine has a A quantity detector is added, and a microcomputer is additionally connected to the control device of the copying machine, and this computer has the function of classifying model patterns into several types and analyzing data according to each pattern. It also has functions such as creation procedures for NC data according to the pattern, as well as functions for creating NC data for rough machining and NC data for finishing machining, so that the operator can see the shape of the model and determine what pattern The pattern and the blank material dimensions, stylus diameter, tool diameter used, interpolation accuracy, remaining allowance, copying area, etc. are entered into the computer as input data, and the stylus is attached to the copying machine head. A copying model for mold finishing is made to copy without any load using a copying machine, and the amount of movement of each axis at that time is imported into a computer moment by moment, and the model shape recognition is performed by analyzing data according to the pattern of the model. and create NC data for rough machining to process an approximate model shape that leaves an appropriate finishing allowance according to the pre-registered blank material dimensions, and NC data for finishing machining that corrects stylus displacement, tool diameter used, and stylus diameter. A method for automating mold machining using a copying model. 2. A three-dimensional copying machine is used that has a stylus that copies the model and has a servo system that determines the direction of movement according to the displacement of the stylus. In this case, a travel amount detector is added to each axis of the copying machine. In addition, a microcomputer is additionally connected to the control device of the copying machine, and this computer is equipped with functions for classifying model patterns into several types, and for analyzing functions according to each pattern and NC according to the patterns.
It has functions such as data creation procedures, as well as functions for creating NC data for rough machining and NC data for finishing machining,
The operator looks at the shape of the model, determines what kind of pattern it corresponds to, and inputs the pattern, the blank material dimensions, stylus diameter, tool diameter used, interpolation accuracy, remaining stock, copying area, etc. as input data. A stylus is attached to the copying machine head, the copying model for mold finishing is made to copy without any load, and the amount of movement of each axis at that time is imported into the computer moment by moment, and the model is recorded. The model shape is recognized through data analysis according to the pattern, and an approximate model shape is machined with an appropriate finishing allowance according to the pre-registered blank material dimensions. Rough cutting NC data, stylus displacement, and tools used are used. A model for copying is characterized in that NC data for finishing machining is created with the diameter and stylus diameter corrected, and the copying machine itself is directly NC-controlled to machine a mold based on this NC data. The mold processing automation method used.