JP2581807B2 - Press die manufacturing method - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a method for manufacturing a press die in a press molding system in which a press molded panel as a product achieves good working accuracy.

(Prior art) As a conventional press die manufacturing method, first, design data (CAD data) of all necessary types of press dies is obtained from body design data representing a panel shape to be formed by press forming, and this design is performed. The press die base material is machined according to the machining data (for example, NC data) obtained based on the data, and the processed press die is brought into contact with a panel (hereinafter referred to as a model panel) manufactured according to the panel shape data. There is a method in which the contact surface between the two is measured by a red hit check or the like, and finish processing is repeated on the press mold until the contact surface covers the entire range. In this method, the finishing often depends on the experience and intuition of the skilled worker, and therefore, the working accuracy of the press die tends to vary.

On the other hand, in recent years, with the progress of the CMM, the shape of the press die machined in the same manner as above was measured with a CMM with high accuracy, and the obtained measurement data and design data were used. Based on the comparison, a method of quantitatively obtaining the position and the amount of finishing of the press die to be processed, and performing the finishing by using them is also adopted. According to this method, the processing accuracy of the press die can be improved as compared with the above-described method.

(Problems to be Solved by the Invention) However, in the above-mentioned two conventional methods, the processing accuracy of the press die itself can be controlled to a predetermined level or more. At that time, it is not always guaranteed that the processing accuracy of the press-formed panel as a product achieves a desired level. For example, when press working is performed 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 panel and the contact surface of the press die are the same. Even if it does, the pressed panel removed from the press die will be deformed by the force applied to the contacting part at the time of die removal, springback, etc., and a processing error with the model panel will occur.

It is preferable to analyze the factors that cause such processing errors and quantitatively grasp them, and feed back the results to the design data of the press die. No feedback is provided, and even if feedback is provided, the deviation between the product and the model panel can be determined by statistical processing of the measured data of the product, and it can only be reflected in the next press type design data, It takes a long time to improve the processing accuracy of the product.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-described problem by obtaining knowledge data on the correlation between the press die and the molded panel from measurement data and correcting the press die design data based on the knowledge data.

(Means for Solving the Problems) For this purpose, the method for manufacturing a press die according to the present invention creates processing data based on predetermined design data when manufacturing a press die that achieves predetermined processing accuracy by machining. Based on this processing data, the shape of the press die manufactured by the NC device was measured, and the shape of the panel formed by press working using this press die was measured. Molding knowledge data is created based on the analysis results of the factors, a molding simulation is performed based on the molding knowledge data, and the predetermined design data of the press die is corrected based on the simulation result.

(Operation) According to the method of the present invention, processing data is created based on predetermined design data, and the shape of the press die manufactured by the NC device based on the processing data and molding by press processing using the press die are performed. The measured shape of the panel is measured, and molding knowledge data is created based on an analysis result of an error factor from the measured data. At this time, since this knowledge data reflects the correlation between the press mold and the press-formed panel as a product by the press mold,
It is possible to simulate how the shape of the panel as a product changes when the shape of the press die is modified, and thus it is possible to determine an appropriate correction amount for the design data of the press die.

This makes it possible to obtain design data of a press die in which a press-formed panel as a product can achieve extremely good accuracy in a very short period of time, and a desired press die can be manufactured based on the design data.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view illustrating an entire configuration of a press die manufacturing system used in an embodiment of the method of the present invention. This system includes a press die processing device 10, a press die measuring device 11,
It comprises a panel measuring device 12 and a control device 13 for comprehensively controlling these devices 11 to 13.

The press-type processing device 10 includes an NC device 20 (not shown).
(Eg a normal NC milling machine) and control it
It comprises an NC controller 21, an interface board 22, and a graphic display 23, and performs machining of a press-type base material based on NC data.

The press-type measuring device 11 includes a rectangular coordinate robot 30, a movement control mechanism and a support mechanism of the robot, and a sensor and the like for functioning as a three-dimensional measuring machine (for details, refer to the applicant of the present application). See Japanese Patent Application No. 1-147956 filed earlier. That is, the press-type measuring device 11 includes a base 31 embedded in the floor via a vibration isolator.
On the surface dug down from the floor surface, a surface plate 32 for mounting the press die 15 to be measured is provided, and the same level as the floor surface of the base 31 so as to surround the surface plate 32. 8 pillars 33 made of concrete are installed on the surface (the reason why they are made of concrete is to reduce the influence of vibration on the measurement), and two fixed beams 34 are fixed on the upper surface of these pillars 33 At the same time, the ends of these fixed beams 34 are connected by fixed beams 35, and an X-axis moving mechanism (not shown) of the fixed beams 34 is provided in the X direction to move the moving beams 36 extending in the arrow Y direction in the X-axis direction. It is movably supported, and Y (not shown) is
An axis moving mechanism is provided to support the movable table 37 so as to be movable in the Y-axis direction, and a Z-axis moving mechanism (not shown) is provided on the movable table 37 to move the lifting arm 38 extending in the Z-axis direction in the Z-axis direction. A sensor 39 (for example, a normal touch sensor) and a θ-axis moving mechanism (not shown) are provided at the lower end of the lifting arm 38 to support the sensor 39 so as to be rotatable in the direction of the arrow θ around the vertical axis. It is configured. The press-type measuring device 11 controls the sensor 39 based on the sensor movement command data in X, Y,
It is moved in the Z and θ-axis directions and is brought into contact with the surface of the press die 15 at an arbitrary position and orientation, and the position data (three-dimensional coordinates) of the contact point is obtained, and the shape of the press die 15 is measured. be able to.

The panel measurement device 12 includes a rectangular coordinate robot 40, a movement control mechanism and a support mechanism of the robot, and a sensor and the like in order to function as a three-dimensional measuring device (for details, refer to the present applicant. Japanese Patent Application No. 63
-310202). That is, the panel measurement device 12
Is provided with a frame 42 on a base 41, supports the robot 40 by this frame 42, and a sensor (a laser type two-dimensional sensor in this example) is attached to a wrist 44 at the lower end of an arm 43 extending in the vertical direction of the robot 40. ) 45, and motors 46, 47, 48, 49, 50 provided in each part as a robot movement control mechanism.
By moving the arm 43 in the directions of the arrows X, Y, and Z, the wrist 44 is moved in the direction of the arrow θ around the vertical axis,
Further, the wrist portion 44 can be swung in the direction of arrow E around the horizontal axis, and therefore, a panel after press forming (hereinafter referred to as a forming panel) mounted on a panel receiving jig 51 installed on the base 41. The shape of the molded panel 16 can be measured by moving the laser type two-dimensional sensor 45 at an arbitrary position and orientation in the three-dimensional space with respect to the shape 16.

The control device 13 includes a minicomputer 60, a CAD computer 61 (for example, a host computer), a memory disk
62, an XY plotter 63 and an input / output terminal device 64 for controlling the above devices 11-13. As shown in FIG. 2, the minicomputer 60 functionally includes a device control unit 70, a measurement data file 71, an external communication unit 72,
Reference data file 73, measurement data creation unit 74, processing
It comprises an NC data creation unit 75, an NC data correction unit 76, and a simulation unit 77. The device control unit 70
An interface for inputting measurement data from the press-type measurement device 11 and the panel measurement device 12 and outputting measurement commands to these devices.The measurement data is stored in the measurement data file 71, and the external communication unit 72 The data is input to the CAD computer 61 and the memory disk 62 via the computer. The external communication unit 72 exchanges signals with the input / output terminal device 64, the XY plotter 63, and the memory disk 62, and
It is an interface that links the CAD computer 61 and the minicomputer 60. The CAD computer 61 stores press type CAD data, body design data (reference data), and molding knowledge data that will be described in detail later, which are stored in a storage device (not shown) of the CAD computer 61. Input to minicomputer 60. External communication unit
Based on the vehicle body design data input to the reference data file 73 via 72, the measurement data creating unit 74 creates press mold and panel measurement data, and moves the press mold measurement device 11 via the device control unit 70. The signals are input to the control mechanism 80 and the movement control mechanism 81 (the motors 46 to 50, etc.) of the panel measuring device 12 and become measurement commands for the robot 30, the sensor 39, the robot 40, and the sensor 45. Also, based on the vehicle body design data, the machining NC data creation unit 75
NC data is created, and the following corrections are made by the NC data correction unit 76, and then input to the NC controller 21 via the device control unit 70 and the interface board 22 of the press-type processing device 10, and based on the NC data, the NC device According to 20, machining of the press-type base material is performed. Here the simulation unit 77
Is the press mold that was once stored in the measurement data file 71.
Based on the measurement data of the molding panel 15 and 15, based on the molding knowledge data input via the external communication unit 72, the following simulation is performed to obtain a press die having a proper range of machining accuracy of the molding panel, Press type CAD
A correction amount for the data is determined, and the press-type CAD data is corrected by the NC data correction unit 76 using the correction amount.

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

That is, first of all, body design data (CA related to panel shape)
D data: standard data), a process plan is made, and all the press dies required to mold the panel specified by the body design data, that is, the model panel, are listed, and each of these press dies is listed. about,
Press type C obtained in advance by CAD computer 61
Based on the AD data (press die design data), NC data for press die machining and data for press die measurement are created. Based on these NC data for machining, machining of the press die base material is performed by the NC device 20 and after machining. The shape of the press die is measured by the press die measuring device 11 based on the press die measurement data. Based on the result of this measurement, it is determined whether rework is required or not. If the deviation from the desired press mold shape is larger than a predetermined value due to unworking, poor processing, etc.
A re-machining command is issued to the NC unit 20, the tool failure of the NC unit 20 is analyzed, and the result is fed back to the NC unit 20. This re-machining is performed by creating machining method improvement data based on the deviation, correcting the machining NC data with the data, and performing the re-machining by the NC device 20 using the corrected machining NC data.

Such reworking is repeated until the deviation falls within a predetermined range, and when the deviation falls within the predetermined range, correction (precision finishing) for finishing as a press die is performed. It is a general method to instruct the total amount of processing until obtaining a number of times in several steps and to increase the processing accuracy step by step.) This correction is performed by the NC device 20 using correction work assistance data (data indicating the position to be corrected and the amount of processing) based on the deviation within a predetermined range, and the shape of the corrected press die is measured by the press-type measuring device.
According to 11, the measurement is performed based on the press-type measurement data.
In this measurement, not only the deviation between the corrected press die shape and the desired press die shape (that is, press die design data) is obtained, but also, for example, the operator directly touches the press die (or the display screen of the graphic display 23). Above)
By visual observation, data on the feeling of unevenness on the surface of the press die is also obtained, and the correction is repeated until the feeling of unevenness on the surface is fed back to the correcting step and the feeling of unevenness on the surface is eliminated. When the predetermined processing accuracy is achieved by the cancellation, the press mold shape data at that time is supplied to the next forming simulation process, and a test punching of press working is performed using this press die, and the obtained formed panel is obtained. Panel shape measuring device 12
Measured by In this measurement, when the deviation between the molded panel and the model panel does not fall within the predetermined range and the predetermined processing accuracy is not achieved, the panel shape data is supplied to the forming simulation process (if the predetermined processing accuracy is achieved, the following processing is performed) Absent).

The molding simulation is performed based on the analysis of the press mold shape data and the panel shape data obtained by the above measurement, and using molding knowledge data created by the CAD computer 61 and stored in a storage device (not shown). That is, the molding knowledge data is for analyzing a processing error factor peculiar to the shape of the model panel (therefore, the shape of the press die) and taking measures against it. Incidentally, as a factor of the processing error, for example, FIG.
(F). Here, FIG.
(B) is referred to as “spring back” and “spring go” for the bending angle of the side wall portion in the groove shape. When a material having a large elastic strain is used, the bending angle is changed by the elastic stress. Due to the recovery, it becomes insufficient or excessive and deforms as shown by the dotted line in the direction of the arrow in the figure. FIG. 3C shows the side wall warp (backward leani) in the flanged square groove shape.
ng), which is a shape defect caused by the panel side wall formed by passing through the edge of the die of the mold being strongly handled and deflected. FIG. This is referred to as scoring, in which the die and the panel slide relatively in the direction of the arrow shown in FIG. FIG. 3E is referred to as “tear” of an end portion or a side wall portion in the drawn shape.
Panel ends and side walls are peeled off as shown in the figure due to undesired force applied to the flanges and beads of the panel. FIG. 7 (f) shows vacuum backing (vacuum backing) of a wide area in the drawn shape. ), And a relatively flat part of a large area of the panel is deformed as shown by a dotted line in FIG. Here, taking the case of springback as an example, the countermeasures will be described. Based on the measured values of the press die and the panel, the data such as the press width dimension, press depth dimension, plate thickness, etc. of the panel and the springback amount data are related. (For example, in the form of a table), and by learning the data accumulated in this way, it is possible to estimate the springback amount of the model panel (press type) of any shape based on the learned knowledge data. Is what you want. Also, in the case of warpage of the side wall portion in the groove shape with the flange portion, sliding scratches of the side wall portion in the drawn shape, and peeling of the end portion and the side wall portion, from the measured values of the press die and the panel, the punch of the press die is used. Forming knowledge data can be obtained by associating the clearance between the die, the height and installation range of the bead, the thickness of the panel, and the degree of the defect with the data, and further, a wide area portion in the drawn shape In the case of vacuum strain, molding is also performed by associating the cross-sectional area and the number of air holes provided in the punches and the like of the press mold with the degree of strain in the wide area of the panel from the measured values of the press mold and panel. Knowledge data can be obtained. In addition, in this molding knowledge data, a large number of circles having a diameter of 10 to 20 mm are drawn in advance at predetermined positions (for example, on the vertical and horizontal center lines) on an unprocessed rectangular panel. Measure the ratio of the major axis and minor axis when deformed into a circle, and analyze the degree of deformation of the panel by the press mold shape from the measurement results.Data obtained by repeating the scribed circle test, At this time, data and the like regarding the minimum bending radius according to the plate thickness that can be bent without breaking the material in each bending process are also stored.

Since the molding knowledge data accumulated in this way is data relating to the correlation between the press die and the molding panel, a molding simulation is performed based on the molding knowledge data to obtain an appropriate correction amount for the press CAD data (the molding simulation data). ) Can be determined, and if the press-type CAD data to which this correction amount is added is updated and stored in a storage device (not shown) of the CAD computer 61 for the next time, the press-formed panel as a product has extremely good accuracy. Can be obtained in a very short time, and a desired press die can be manufactured based on the design data.

(Effect of the Invention) As described above, the method for manufacturing a press die according to the present invention is as follows.
Knowledge data on the correlation between the press mold and the molded panel is obtained from the measured data, and the press mold design data is corrected based on this knowledge data. , Design data can be obtained in a very short time,
A desired press die can be manufactured based on the design data.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating the entire configuration of a press die manufacturing system used in an embodiment of the method of the present invention, FIG. 2 is a diagram showing the configuration of a control system of the system, and FIG. FIGS. 4 (a) to 4 (f) are diagrams for explaining a process error factor of the press-formed panel. 10 Press machine, 11 Press measuring device 12 Panel measuring device, 13 Control device 15 Press die 16 Molded panel (panel after molding) 20 NC device, 60 …… Mini computer 61 …… CAD computer

Claims (1)

(57) [Claims] When manufacturing a press die that achieves a predetermined processing accuracy by machining, processing data is created based on predetermined design data, and a shape of the press die manufactured by an NC device based on the processing data is provided. Along with measuring the shape of the panel formed by press working using this press mold, forming the forming knowledge data based on the analysis results of the processing error factors from these measurement data, A method for manufacturing a press die, wherein a molding simulation is performed based on the result, and the predetermined design data of the press die is corrected based on the simulation result.