JPH03104537A - Manufacture of press die - Google Patents

Abstract

PURPOSE:To manufacture a desired press die, by finding the knowledge data concerning the correlated relation of a press die and forming panel from the measured data of both and correcting the press die design data based on this knowledge data. CONSTITUTION:A working data is prepared based on a specific design data, the shape of the press die manufactured by the press die working device 10 composed of an NC device is measured by a press die measuring device 11 based on this working data, the panel formed by pressing with this press die is measured by a panel measuring device 12 and a forming knowledge data is prepared by a control device 13 based on the analyzed result of the error factors of those measured data. This knowledge data reflects the correlative relation of the press die and the press forming panel as for a product by the press die, so how is the panel shape as a product changed in the case of correcting the press die shape can be subjected to simulation and the optimum correction for the design data of the press die can be decided.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for manufacturing a press mold in a press molding system such that a press molded panel as a product achieves good processing accuracy.

(Prior art) In the conventional press mold manufacturing method, first, design data (CAD data) for all types of press molds required are obtained from car body design data representing the panel shape to be shaped by press molding. The press die base material is machined using machining data (for example, NC data) obtained based on the design data, and the press die after processing is a panel manufactured according to the panel shape data (hereinafter referred to as a model panel).
There is a method in which the contact surface between the two is measured by a red contact check etc., and the finishing process is repeated on the press mold until the contact surface covers the entire range.

In this method, the finishing process often depends on the experience and intuition of skilled workers, and therefore variations in the processing accuracy of the press die are likely to occur.

On the other hand, in recent years, with the advancement of coordinate measuring machines, the shape of the press die machined in the same manner as above is measured with high precision using a coordinate measuring machine, and the obtained measurement data and design data are combined. A method has also been adopted in which the position and amount of finishing of this press mold are quantitatively determined based on the comparison, and finishing is carried out based on these. According to this method,
The processing accuracy of the press mold can be improved compared to the method described above.

(Problem to be Solved by the Invention) However, in the two conventional methods described above, the processing accuracy of the press die itself can be controlled to a predetermined level or higher; At this time, it is not always guaranteed that the processing accuracy of the press-formed panel as a product will achieve the desired level. For example, when pressing is carried out using a press die manufactured according to design data, when the panel to be formed is pressed and pressed against the press die, the shapes of the contact surfaces of this panel and this press die are the same. Even if the press-formed panel is removed from the press die, deformation occurs due to force applied to the parts that come into contact with the press die, springback, etc., resulting in processing errors with the model panel.

It would be preferable to analyze and quantitatively understand the factors that cause such machining errors, and feed the results back into the press die design data, but since such analysis was difficult,
In the conventional example above, no feedback is provided from the product, and even if feedback is provided, the deviation between the product and the model panel is determined by statistical processing of the product measurement data, and it is simply used as the design data for the next press die. It takes a long time to improve the processing accuracy of the product because it can only be reflected in the process.

The present invention aims to solve the above-mentioned problems by obtaining knowledge data regarding the correlation between the press mold and the molded panel from measurement data, and correcting the press mold design data based on this knowledge data.

(Means for Solving the Problems) For this purpose, the press mold manufacturing method of the present invention creates processing data based on predetermined design data when manufacturing a press mold that achieves a predetermined processing accuracy by machining. Then, based on this processing data, we measured the shape of the press mold manufactured by the NG device, measured the shape of the panel formed by press processing using this press mold, and analyzed the error factors of these measurement data. The present invention is characterized in that molding knowledge data is created based on the molding knowledge data, and the predetermined design data of the press die is modified based on the molding knowledge data.

(Function) According to the method of the present invention, processing data is created based on predetermined design data, and the shape of a press mold manufactured by an NC device based on this processing data and the press processing using this press mold are improved. The shape of the shaped panel is measured, and molding knowledge data is created based on the analysis results of error factors of these measurement data. At this time, this knowledge data reflects the correlation between the press die and the press-formed panel as a product made by that press die, so it can be used to determine how the panel shape as a product changes when the press die shape is modified. Therefore, it is possible to determine an appropriate correction amount for the design data of the press die.

As a result, it is possible to obtain design data of a press mold that can achieve extremely high precision in a press-formed panel as a product in an extremely short period of time, and it is possible to manufacture a desired press mold using this design data.

(Example) Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 is a perspective view illustrating the overall configuration of a press die manufacturing system used in an embodiment of the method of the present invention, and this system includes a press die processing device IO, a press die measuring device 11, and a panel measuring device 12. further comprising these devices If
-13 is provided with a control device 13 for comprehensive control.

The press mold processing device 10 includes an NC device 20 (not shown here) (for example, a normal NC milling machine), an NC controller 21 for controlling the same, and an interface board 22.
Also equipped with a graphic display 23,
The press die base material is machined based on NC data.

In order to function as a three-dimensional measuring machine, the press-type measuring device 11 is equipped with a Cartesian coordinate-type robot 30, a movement control mechanism and a support mechanism for this robot, a sensor, etc. (details are provided in the present application). (Please refer to Japanese Patent Application No. 1-147956 filed earlier by Mr. That is, the press mold measuring device 11 includes a surface plate 32 for placing the press mold 15 as a measurement object on a surface dug below the floor surface of a base 31 buried in the floor via a vibration isolating material. Eight concrete supports 33 are installed on the same level as the floor of the base 31 so as to surround this surface plate 32 (the reason for using concrete here is to prevent the influence of vibration on measurement. ), these pillars 3
Two fixed beams 34 are fixed to the upper surface of 3, and the ends of these fixed beams 34 are connected by a fixed beam 35, and an X-axis moving mechanism (not shown) is provided in the direction of the arrow X of the fixed beam 34 to move the fixed beams 34 in the direction of the arrow Y. A movable beam 36 extending in the direction of the X-axis is supported, and a Y-axis moving mechanism (not shown) is provided on the movable beam 36 to support a movable table 37 movably in the Y-axis direction. 37 is provided with a Z-axis moving mechanism (not shown) to support the lifting arm 38 extending in the Z-axis direction so as to be movable in the Z-axis direction,
Furthermore, a sensor 39 (for example, a normal Cucci sensor) and a θ-axis movement mechanism (not shown) are provided at the lower end of the lifting arm 38, and the sensor 39 is supported so as to be rotatable in the direction of the arrow θ about the vertical axis. . This press mold measuring device 11 moves the sensor 39 in the x, y, z, and θ-axis directions based on sensor movement command data to measure the press mold 1.
The shape of the press die 15 can be measured by contacting the surface of the press die 15 at an arbitrary position and posture to obtain position data (three-dimensional coordinates) of the contact point.

The panel measurement device 12 functions as a three-dimensional measuring device, and therefore includes a Cartesian coordinate robot 40, a movement control mechanism and a support mechanism for this robot, and sensors (the details of which are provided by the applicant). (See Japanese Patent Application No. 63-310202). That is, the panel measuring device l2 includes a frame 42 provided on a base 4l, which supports the robot 40, and a sensor (in this example, A laser type two-dimensional sensor) 45 is installed, and a motor 46 is installed at each part as a robot movement control mechanism. 47. 4B, 49. 50
The arm 43 is moved in the direction of arrow X. While moving in the Y and Z directions, the wrist portion 44 can be moved around the vertical axis in the direction of arrow θ, and the wrist portion 44 can also be swung around the horizontal axis in the direction of arrow E, so that it can be installed on the base 41. The laser type two-dimensional sensor 45 is moved at an arbitrary position and orientation in three-dimensional space with respect to the panel (hereinafter referred to as the "gata panel") l6 after press molding, which is placed on the panel receiving jig 51. The shape of the shaped panel 16 of the lever can be measured.

The control device 13 includes a minicomputer 60, a CAD computer 61 (for example, a host computer), a memory disk 62, an X-Y plotter 63, and an input/output terminal device 64, and controls each of the devices 11 to 13. It is something to return to. As shown in FIG. 2, the ξ2 computer 60 functionally includes an equipment control section 70, a measurement data file 71, an external communication section 72, a reference data file 73,
Measurement data creation section 74, processing NC data creation section 75
, NC data correction section 76 and simulation section 77
It is a certain thing with the following. The device control unit 70 is an interface for inputting measurement data from the press type measuring device 11 and the panel measuring device l2 and outputting measurement commands to these devices, and the measurement data is stored in a measurement data file 71, Furthermore, the information is manually inputted to the CAD computer 61 and the memory disk 62 via the external communication section 72. The external communication unit 72 is connected to the input/output terminal device 64,
This is an interface that exchanges signals with the Y plotter 63 and the memory disk 62, and also links the CAD computer 6l and the minicomputer 60.
Press type CAD data and vehicle body design data (reference data) stored in a storage device (not shown) of the computer 61
and molding knowledge data, which will be detailed later, are input into the minicomputer 60. Based on the vehicle body design data input to the standard data file 73 via the external communication section 72, measurement data for the press mold and panel is created in the measurement data creation section 74, and the press mold and panel are created via the equipment control section 70. Movement control mechanism 80 of measuring device 11 and panel measuring device 12
robot 30, sensor 39 and robot 40,
This becomes a measurement command for the sensor 45. Further, based on the car body design data, NC data for press mold processing is created in the processing NC data editing section 75, and NC data for press mold processing is created by the NC data correction section 76.
After making the following corrections, it is input to the NC controller 21 via the equipment control unit 70 and the interface board 22 of the press mold processing device 10, and based on this NC data, N is
The C device 20 performs machining of the press die base material.

Here, the simulation section 70 performs the following simulation based on the measurement data of the press die 15 and the forming panel 16 that have been temporarily stored in the measurement data file 71 and using the forming knowledge data input manually via the external communication section 72. Then, a correction amount for the press mold CAD data is determined in order to obtain a press mold that makes the processing accuracy of the molded panel within an appropriate range, and the NC data correction section 76 corrects the press mold CAD data using this correction amount. .

Using such a press mold manufacturing system, a press mold is manufactured by the method of the present invention through the steps shown in FIG.

In other words, first, car body design data (CA regarding panel shape)
D data (2 standard data), perform a process plan, list all the press dies required to form the panel shape of the panel specified by this car body design data, that is, the model panel, and about,
The CAD computer 61 creates press mold processing NC data and press mold measurement data based on press mold CAD data (press mold design data) obtained in advance, and the NC device 20 presses the press mold based on this processing NC data. The mold base material is machined, and the shape of the press mold after machining is measured by the press mold measuring device 11 based on the press mold measurement data. Based on the results of this measurement, it is determined whether re-processing is required, and if the deviation from the desired press mold shape is larger than a predetermined value due to unprocessed or defective processing, a re-processing command is issued to the NC device 20, At the same time, tool defects are analyzed by the NC device 20 and the results are sent to the NC
Feedback is provided to the device 20. This reprocessing is performed by creating processing method improvement data based on the deviation, correcting the processing NC data using this data, and using the corrected processing NC data by the NC device 20.

Such reprocessing is repeated until the deviation falls within a predetermined range, and once it is within a predetermined range, corrections (precision finishing) are performed to finish the press die (in press die processing, the final press die shape is A common method is to instruct the total machining amount in several steps to increase the machining accuracy step by step). This correction is performed by the NC device 20 using correction work assistance data (data representing the position to be corrected and the amount of processing) based on the deviation within a predetermined range, and the shape of the press die after correction is measured by the press die measuring device. 1l based on the press mold measurement data. In this measurement, in addition to determining the deviation between the corrected press die shape and the desired press die shape (i.e., press die design data), for example, the operator directly measures the press die (or on the display screen of the graphic display 23). (above) Data regarding the unevenness of the surface of the press mold is also obtained by visual inspection, and this unevenness data is fed back to the correction step, and the correction is repeated until the unevenness of the surface is eliminated, Once the unevenness has been eliminated and the specified machining accuracy has been achieved, the press mold shape data at that time is supplied to the next process, the molding process, and the press mold is used to test press work. The shape of the obtained molded panel is measured by a panel measuring device l2. In this measurement, if the deviation between the formed panel and the model panel does not fall within a predetermined range and the predetermined processing accuracy cannot be achieved, the panel shape data is supplied to the forming simulation process (if the predetermined processing accuracy is achieved) (Do not perform the following processing.)

This molding simulation is performed using molding knowledge data created by the CAD computer 61 and stored in a storage device (not shown), based on an analysis of the press mold shape data and panel shape data obtained by the above measurements. That is, this molding knowledge data is used to analyze processing error factors specific to the shape of the model panel (therefore, the shape of the press mold) and to take countermeasures.

By the way, as for this processing error factor, for example, Fig. 4 (a)
) to (f). Figures (a) and (b) show what is called spring back or spring go, which occurs when a material with large elastic strain is used and the bending angle becomes insufficient or excessive due to elastic stress recovery. It deforms in the direction of the arrow shown in the figure as shown by the dotted line. The figure (C) shows the sled (ba
This is called ckward leaning, and is a shape defect caused by the warping of the side wall of the panel that passes through the edge of the mold.
This is called g) and is caused by the tool of the NC device and the workpiece slipping in the direction of the arrow in the figure, resulting in scratches as shown by dotted lines.

Figure (e) is also referred to as tear, in which the end or part of the panel is torn off as shown in the figure due to undesired force applied to the flange or bead. f) is vacuum strain
ng), in which the panel deforms as shown by the dotted line in the figure due to a defect in air release caused by the vertical movement of the press die. Taking the case of springback as an example, we will explain countermeasures against it. Based on the measurement values of the press die and panel, we will correlate data such as the press width dimension, press depth dimension, plate thickness, etc. of the panel with the springback amount data. Molding knowledge data that can be stored in memory (for example, in a table), and from learning the data accumulated in this way, the amount of springback can be estimated for any shape of model panel (press mold). This is what we seek. Furthermore, this molding knowledge data includes drawing a large number of circles with a diameter of IO to 20InII in advance on a raw rectangular panel at predetermined positions (for example, on the vertical and horizontal center lines), and then drawing the circles of each part by the rectangular shape of this panel. The major axis when transformed into a circle,
Data obtained by repeating the scribed circle test, in which the short axis ratio is measured and the degree of deformation of the panel due to the press die shape is analyzed from the measurement results, and the material is measured for each bending process during press bending. Data regarding the minimum bending radius that can be bent without cracking depending on the plate thickness shall also be stored.

Since the forming knowledge data accumulated in this way becomes data regarding the correlation between the press die and its oval panel, the press die CAD data is appropriately corrected by performing the shaping operation using this forming knowledge data. The amount (molding simulation data) can be determined, and if the press mold CAD data including this correction amount is updated and stored in the storage device (not shown) of the CAD computer 61 for the next time, the product Design data for a press die that allows a press-formed panel to achieve extremely high precision can be obtained in an extremely short period of time, and a desired press die can be manufactured using this design data.

(Effects of the Invention) Thus, as described above, the press mold manufacturing method of the present invention obtains knowledge data regarding the correlation between the two from measurement data of the press mold and the molded panel, and corrects the press mold design data based on this knowledge data. From this, it is possible to obtain design data of a press mold that can achieve extremely good precision in a press molded panel as a product in an extremely short period of time, and a desired press mold can be manufactured using this design data.

[Brief explanation of drawings]

FIG. 1 is a perspective view illustrating the overall structure of a press mold manufacturing system used in an embodiment of the method of the present invention, FIG. 2 is a diagram showing the configuration of the control system of the system, and FIG. Diagrams showing the press mold manufacturing process, FIGS. 4(a) to 4(f) are diagrams for explaining processing error factors of the press-shaped panel. IO...Press mold processing device 1l...Press mold measuring device 12...Panel measuring device 13...Control device 15...Press mold l6...Molding panel (panel after molding) 20...・N
C device 60...tanni computer 6l...
・Computer for CAD

Claims (1)

[Claims] 1. When manufacturing a press mold that achieves a predetermined processing accuracy through machining, processing data is created based on predetermined design data, and the press mold is manufactured using an NC device based on this processing data. Measure the shape of the panel formed by press processing using this press mold, create molding knowledge data based on the analysis results of error factors of these measurement data, and press based on this molding knowledge data. A method for manufacturing a press mold, comprising modifying the predetermined design data of the mold.