JPH02139166A - Method and device for polishing die - Google Patents

Abstract

PURPOSE:To make the pressurizing direction of a tool constant irrespective of the inclination of the die surface by calculating the shape or a corresponding segment based on a teaching point set parameter and vertically pressing a polishing tool to the die surface based on the calculated segment shape, preset polishing conditions and set boundary. CONSTITUTION:The teaching data of plural points for setting boundary are held on a boundary data holding means 21 by corresponding to the plural segments constituting the die surface and the teaching data of the minimum points necessary for determining the shape of a segment and/or the parameter necessary for determining the shape of each segment are held on determining data holding means 22, 24. The shape of the corresponding segment is then calculated by a shape calculating means 25 based on the teaching data hold on the determining data holding means and/or set parameter and the polishing tool is vertically pressed to the die surface based on this segment shape, set polishing conditions and boundary.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a mold polishing method and apparatus, and more specifically, to a mold polishing method applied when polishing a mold using a robot. METHODS AND APPARATUS THEREOF.

<Prior art and problems to be solved by the invention> As a conventional mold polishing device using a robot, ■ It has a front-back slide axis, a vertical slide axis, a horizontal rotation axis, and a vertical rotation axis. Things (see Figure 6)
, ■ A device with a vertical slide axis, a front-rear slide axis, and a vertical rotation axis (see Figure 7), and ■ A device with a vertical slide axis, a horizontal rotation axis, and a vertical rotation axis (see Figure 8). (see figure) is provided. still,
In FIGS. 6 to 8, shafts whose insides are painted black are those that are manually rotated.

Each of the above-mentioned mold polishing devices directly teaches the mold surface according to the polishing operation order, performs the actual mold polishing operation based on the obtained large amount of teaching data, or By teaching an arbitrary point and performing linear interpolation calculations between adjacent teaching points, a large amount of teaching data is obtained, and the actual mold polishing operation is performed based on the obtained large number of teaching data. I have to.

Therefore, in any mold polishing apparatus, once all necessary teaching data is obtained, the surface of the mold can be polished automatically by causing the robot to operate based on the teaching data.

<Problem to be solved by the invention> Even in the mold polishing device configured in the above direction, the work to obtain all the necessary teaching data is extremely complicated;
There is a problem that the automation rate of mold polishing cannot be sufficiently increased, and there is also a problem that the quality of the finished surface cannot be sufficiently improved.

In other words, regarding the workability of obtaining teaching data, if the direct teaching method is used, teaching data must be obtained sequentially along the route in which the polishing tool is to be moved, and a data setting operation is required for each teaching point. At the same time, since the number of teaching points increases significantly, the teaching work as a whole becomes complicated and the required time becomes significantly longer. In addition, if the method is to perform teaching work only on arbitrary points and obtain teaching data for other points by linear interpolation calculation, the number of points that need to be actually taught will be reduced compared to the direct teaching method. It is possible, but
In order to approximate the teaching data obtained by the linear interpolation calculation to the mold surface with high precision, it is necessary to teach quite a large number of points, and the teaching work is still complicated and takes a long time. Therefore, in the mold polishing apparatus shown in FIGS. 6 to 8, a copying method is introduced, and for example, a teaching operation must be performed each time the polishing pattern is changed.

Since molds are generally produced in small quantities, and most commonly produced in one piece, the frequency with which the above-mentioned teaching work is performed becomes extremely high, which also causes the above-mentioned problems. cannot be completely ignored.

Regarding the quality of the finished surface, the polishing tool in any of the mold polishing apparatuses is attached by a universal joint, and the polishing tool is pressed against the mold surface by the universal joint. Therefore, depending on the inclination of the polishing position and the teaching data, the pressing direction of the polishing tool will be perpendicular to the mold surface or tilted, as shown in Figure 9, and the entire mold surface will be covered. It becomes almost impossible to apply a uniform pressing force over the range. Furthermore, the direction of robot movement for moving the polishing tool is predetermined by the teaching data, and is generally different from the tangential direction of the mold surface. Even if - is constant, the amount of movement of the polishing tool changes, and furthermore, it is impossible to perform a teaching operation in which the amount of robot movement is changed in order to keep the amount of movement of the polishing tool constant.

As a result, the pressure applied for brushing changes depending on the location, and the polishing speed also changes depending on the location.
It is impossible to obtain uniform polishing accuracy over the entire range of the mold surface.

<Object of the Invention> The present invention has been made in view of the above-mentioned problems, and provides a mold polishing method and device that can significantly simplify the teaching work and provide a polished surface of extremely high quality. is intended to provide.

Means for Solving the Problems To achieve the above object, the mold polishing method of the present invention divides the mold surface into segments and teaches each segment a plurality of points for boundary setting. In addition to carrying out
The minimum number of points required to determine the shape of each segment is taught and/or the parameters required to determine the shape of each segment are set.
Or, the robot arm calculates the shape of the corresponding segment based on the set parameters, and presses the polishing tool perpendicularly to the mold surface based on the calculated segment shape, preset polishing conditions, and set boundaries. This is how to make it work.

However, the above parameter may be any parameter that identifies at least the type of shape.

In order to achieve the above object, the mold polishing apparatus of the present invention includes boundary data holding means, confirmation data holding means, shape calculation means, and control means.

The boundary data holding means holds teaching data of a plurality of points for boundary setting in correspondence with a plurality of segments constituting the mold surface. It holds the teaching data of the minimum number of points required for finalization and/or the parameters necessary for determining the shape of each segment, and the shape calculating means is held in the final data holding means. The control means calculates the shape of the corresponding segment based on teaching data and/or setting parameters, and the control means performs polishing based on the calculated segment shape, preset polishing conditions, and set boundaries. The robot arm is operated to press the tool perpendicularly to the mold surface.

With the mold polishing method described above, multiple points for boundary setting are taught for each divided segment, and the minimum number of points necessary to determine the shape of each segment is taught. and/or set the parameters necessary to determine the shape of each segment, calculate the shape of the corresponding segment based on these, and calculate the shape of the calculated segment, the brushing conditions set in advance, and Since the robot arm is operated to press the polishing tool perpendicularly to the mold surface based on the set boundary, even if the area of the segment becomes large, only a small amount of teaching data needs to be obtained. The teaching work can be significantly simplified.

Since the pressing direction of the polishing tool is kept constant regardless of the inclination of the mold surface, uniform polishing performance can be exhibited over the entire range, and the quality of the polished surface can be significantly improved.

However, the above parameter may be any parameter that at least identifies the type of shape, and the same effect as above can be achieved.

In the mold polishing device having the above configuration, the boundary data holding means holds teaching data of a plurality of points for boundary setting corresponding to the plurality of segments constituting the mold surface, and It is only necessary that the teaching data of the minimum number of points required to determine the shape and/or the parameters necessary to determine the shape of each segment are held in the determining data holding means. The shape calculation means calculates the shape of the corresponding segment based on the teaching data and/or setting parameters held in the , and the shape of the calculated segment,
Based on preset polishing conditions and preset boundaries, the control means operates the robot arm to press the polishing tool perpendicularly to the mold surface, thereby polishing and scraping the mold surface. Therefore, even if the area of the segment becomes large, it is only necessary to obtain teaching data for a significantly smaller number of points, and the teaching work can be significantly simplified. Since the pressing direction of the polishing tool is kept constant regardless of the inclination of the mold surface, uniform polishing performance can be exhibited over the entire range, and the quality of the polished surface can be significantly improved.

<Example> Hereinafter, embodiments will be described in detail with reference to the accompanying drawings showing examples.

FIG. 3 is a schematic diagram showing an example of a mold polishing robot for carrying out the mold polishing method of the present invention, in which figure A is a front view, figure B is a side view, and figure C is a plan view. be.

A first shaft (2) that moves in the left-right direction is provided at the top of the machine frame (1), and a second shaft (3) that moves in the front-back direction with respect to the first shaft (2) is provided. A third shaft (4) is provided that moves vertically with respect to the second shaft (3).

A fourth axis (6) that rotates in a horizontal plane is provided at the lower end of the third axis (4), and a fifth axis (6) that rotates in a plane perpendicular to the fourth axis (5) is provided. ) is provided. Further, a work table (7) is provided at a predetermined position below the machine frame (1), and at least a portion of the work table (7) that supports the work is configured to be movable up and down. Further, a tool magazine S) is provided at a predetermined position on the machine frame (1). Note that the first axis to the third axis (4) is operated by a direct drive motor, and the fourth axis (5) and the fifth axis (6) are operated by rotary direct drive motors. In this way, the operating force during direct teaching is reduced. Further, the fifth shaft (6) supports the polishing tool via a floating mechanism, and controls the pressing force of the polishing tool by supplying pressure fluid to the floating mechanism. .

In this case, it is preferable that the polishing tool be mounted on a plurality of surfaces, and that the mounting surface be selected depending on the rotating surface, swing direction, etc. of the polishing tool.

FIG. 4 is a schematic block diagram showing an example of the configuration of the mold polishing device, which includes a robot body (9), a robot/nod controller 00), and a system controller (11). The system controller (11) is connected to a display device (12), a keyboard (13), and a memory device (14), and the system controller (11) is connected to a display device (12), a keyboard (13), and a memory device (14).
13) Calculates the shape based on the parameters etc. set through 13), generates the command data necessary to press the polishing tool perpendicularly to the surface based on the calculated shape, and also maintains the boundary data, etc. This is what we do. The robot controller 00) is equipped with a teaching pendant (15).
) is connected, and outputs a robot operation command signal based on a signal from the teaching pendant (15), or outputs a robot operation command signal based on command data from the system controller (11). The robot body (9) is connected to an automatic tool changer (16) and peripheral devices (17) such as a tool magazine, and performs necessary robot operations based on robot operation command signals from the robot controller 00). It is something. In addition, as other peripheral devices (17'), a table lifting device, a grinding fluid circulation device, etc., which are electrically controlled by a separate system, are provided.

FIG. 1 is a flowchart showing an embodiment of the mold polishing method of the present invention, in which initial setting operations such as returning to the origin are performed in step (2), and then the operator or the like visually determines the surface of the mold in step (2). Split into multiple segments. Then, in step 2, parameters indicating the type of shape, such as flat, spherical, cylindrical, etc., are set for each segment, and in step 2, each segment is set with a contact sensor for teaching attached to the robot. Teach the minimum number of points necessary to determine the boundary, if necessary, teach the minimum number of points required to determine the shape of each segment, and in step Set the parameters, for example, the radius if it is a spherical surface, cylindrical surface, etc., and in step 2, calculate the shape equation of the corresponding segment based on the teaching data and setting parameters, and display the segment visually if necessary. This visually determines whether there is a teaching error. Then, in step (2), it is determined whether the shape equations have been calculated for all segments, that is, whether or not the teaching has been completed.If the teaching has not been completed, the processing from step (2) is performed again.

If it is determined that the teaching is completed in step ■, a polishing segment is selected in step ■, a polishing tool is selected in step ■, a polishing pattern is selected in step [phase], and the polishing condition parameters are selected in step ■. For example, set the pitch, feed speed, direction, etc., and display the simulation data of the polishing operation on the display device (
12) to visually judge whether the setting conditions are appropriate or not. Then, in step 0, parameters such as the rotation speed of the polishing tool are set, and in step [Yes], a polishing operation is performed based on the set parameters,
In step (2), it is determined whether or not the polishing operation should be continued for the same segment by visually judging the polishing results, and if it is determined that the polishing operation should be continued,
Repeat the process following step (■). Therefore, when performing the polishing operation again, it is easy to change the polishing pattern, and there is no need for re-teaching associated with changing the polishing pattern. Conversely, if it is determined in step ■ that there is no need to continue the polishing operation, it is determined in step ■ whether or not it is necessary to change the polishing segment, and if it is determined that it is necessary to change it, Then, perform the process from step (2) again. Conversely, if it is determined that there is no need to change, the series of mold polishing operations is ended.

Figure 2 is a schematic diagram for explaining the teaching points and parameters necessary to calculate the shape equation of a segment.
, B2. B3. B4 shows the case where the segment is a cylindrical surface.

In these figures, the points indicated by black circles are teaching points for boundaries, and the points indicated by white circles and the points indicated by square corners are teaching points for shape determination.

A1 in the figure shows a plane with an arbitrary inclination, and the point P
1 to P5 are taught as boundary points, and 4 included in the boundary
Points P6 to P9 are taught as points for confirmation. Then, the coordinate values of each teaching point are substituted for the equation of the above plane as z - α
Each coefficient α, β,
By determining γ, it is possible to significantly suppress errors caused by unevenness due to cutter marks on the mold surface, measurement accuracy of the device, etc., and calculate a highly accurate plane equation.

In the above explanation, the plane equation was calculated based on the boundary point outside the fishing gear, but it is also possible to calculate the plane equation using the boundary point. In this case,
The number of taught points can be reduced to achieve a similar degree of accuracy, or accuracy can be improved without increasing the number of taught points.

A2 in the same figure shows a horizontal plane, and the plane equation is zm
c, so if you give a parameter indicating that it is a horizontal plane, you can create a highly accurate plane equation by just teaching the boundary points PI to P5. It shows a cylinder, and the point P
Teach L-P5 as a boundary point and 8 included in the boundary
The point pe-pta is taught as a point for determination. However, the four points P6 to P9 and the four points PIO to P13 are points that can be approximated on different circumferences. Then, suppose the coordinates of the center of the circle are (xO, yO).

zO), the coordinate values are determined (by the least squares method) so that the sum of the squares of the distances to the four points P6 to P9 is the minimum, and the average distance between the center and each point is defined as the radius. The coordinate values and radii of the centers are determined in the same manner for the other four pto-pias. Next, by determining the direction of the axis of the cylinder based on the coordinate values of the two centers, the curved surface equation of the cylinder can be obtained. Furthermore, by increasing the number of points for confirmation, a more accurate surface equation can be obtained, or even if the surface equation is converged by resolving it multiple times, a more accurate surface equation can be obtained. .

82 in the same figure shows the case of a cylinder whose axis is oriented in the vertical direction. In this case, there is no need to determine the direction of the axis, so the number of points for determination is reduced to 1/2 of that in the case of 81 in the same figure. can be reduced.

B3 in the same figure shows the case of a cylinder with the axis pointing in the horizontal direction. In this case as well, there is no need to find the direction of the axis, so the number of points for determination is reduced to half of that in the case of 81 in the same figure. can be done. Incidentally, since this is often the case in actual molds, there are many cases in which the number of teaching points can be reduced.

84 shows a case where the end face of the cylinder is included within the boundary, and shows points P1 to P5゜P"4.P"5 for determining the area, points P14 to P17 for determining the axial direction, and the radius and axial position. Points P6 to P9 for confirmation are taught. And point P4.
P5. Points PL4 to P in the area surrounded by P''5.P-4
A plane equation is determined from the coordinate values of L7 by the least squares method, and the direction perpendicular to the plane is determined as the axial direction. Next, each of the points P6 to P9 is projected onto a cross section perpendicular to the determined axis, and the center and radius of the circle are determined using the least squares method using the projected points to obtain a curved surface equation.

Although only planes and cylinders have been described above, surface equations can also be obtained for curved surfaces such as spheres and cones by simply teaching significantly fewer points than in the case of direct teaching.

After obtaining the plane equation or curved surface equation as described above, you can easily calculate the direction for vertically pressing the polishing tool in correspondence with the actual polishing position. By operating each axis of the robot based on this, it is possible to perform the polishing operation with a uniform pressing force over the entire surface of the mold, and when moving the polishing tool, it is possible to apply pressure in the tangential direction of the mold surface. Since it can be moved at a predetermined speed, the entire area can be polished evenly.

FIG. 5 is a block diagram showing an embodiment of the mold polishing device of the present invention, which includes a boundary data memory (21) that holds teaching data for boundaries, and confirmation data that holds teaching data for confirmation. A memory (22) and a boundary data memory (21) selectively store the teaching data taken in by the teaching operation.
) or the confirmation data memory (22), the confirmation parameter memory (24) that holds the confirmation parameters input from the keyboard, etc., the confirmation data memory (22) and the confirmation data memory (22), An arithmetic section (25), whose main part is a CPU, performs necessary arithmetic operations based on the data and parameters read from the parameter memory (24) to calculate a plane equation or a curved surface equation, and an equation unit that holds the arithmetic results. memory (2B), a brushing parameter memory (27) that holds parameters for the brushing operation input from the keyboard, etc., and equations and parameter memory (27) read out from the memory (2B).
A robot operation that generates a robot operation command signal to achieve a brushing tool pressing state perpendicular to the mold surface based on the parameters read from 27) and the data read from the boundary data memory (21). Control unit (
28). However, the above selector (23),
For the robot motion control unit (28), the calculation unit (25)
In addition, each of the memories described above may be partitioned into one memory area and each partitioned area may be allocated.

With the mold polishing device having the above configuration, simply by operating the selector (23) in accordance with whether the teaching data is for boundaries or for confirmation, the teaching data for boundaries can be changed to It is stored in the data memory (21) or the confirmation data memory (22).

Since the parameters for confirmation entered through the keyboard etc. are stored in the parameter memory for confirmation (24), the data for the segments constituting the mold surface are read from the data memory for confirmation (22), and A plane equation or a curved surface equation is obtained by reading the parameters from the determining parameter memory (24) and supplying them to the calculation unit (25), and storing them in the equation memory (26). The above operations are performed for each segment, so
Boundary teaching data corresponding to all segments is stored in the boundary data memory (21), and plane equations or curved surface equations corresponding to all segments are stored in the equation memory (2B).

After that, the polishing tool, polishing pattern, etc. are stored in the parameter memory (27) through the keyboard, etc., so the equation corresponding to the polishing segment is read out from the memory (26), and the parameters and boundaries read out from the parameter memory (27) are read out from the memory (26). Based on the data read from the data memory (21), the robot motion control unit (28
), a robot operation command signal is generated to achieve a state in which the polishing tool is pressed perpendicular to the mold surface.

As a result, a corresponding segment can be polished by moving the polishing tool at a predetermined tangential movement speed while pressing the polishing tool perpendicularly to the mold surface.

This polishing operation may be repeated multiple times if a high-precision finish is required, but it is not necessary to polish the same segment each time by changing the polishing pattern. Finishing accuracy can be improved.

That is, since the plane equation or curved surface equation is stored, there is no need to perform a special teaching operation even if the polishing pattern is changed, and work efficiency can be significantly improved.

By performing the above polishing operation on all segments, the entire surface of the mold can be polished with high precision.

Note that the present invention is not limited to the above-described embodiments. For example, it is possible to perform teaching using a joystick instead of direct teaching using a teaching head, and depending on adjacent segments, it is possible to perform teaching using a joystick. It is possible to calculate a plane equation or a curved surface equation by teaching points, and it is also possible to select a polishing tool and set parameters for polishing automatically according to the number of times of polishing, and other functions. Various design changes can be made without departing from the gist of the invention.

<Effects of the Invention> As described above, in the first invention, even if the area of the segment becomes large, it is only necessary to obtain teaching data for a significantly small number of points.
In addition to significantly simplifying the teaching work, the pressure direction of the polishing tool is kept constant regardless of the inclination of the mold surface, so uniform polishing performance can be achieved over the entire range, improving the quality of the polished surface. It has the unique effect of significantly increasing the

The second invention has the unique effect that the type of calculation can be easily selected based on the parameters, and that a highly accurate plane equation or curved surface equation can be obtained with teaching data of a small number of points.

In the third invention, even if the area of the segment becomes large, only a small amount of teaching data needs to be obtained, and the teaching work can be significantly simplified, and the polishing tool can be applied regardless of the inclination of the mold surface. Since the pressure direction is constant, uniform polishing performance can be achieved over the entire range, and the unique effect of significantly improving the quality of the polished surface is achieved.

[Brief explanation of the drawing]

Fig. 1 is a flowchart showing an embodiment of the mold polishing method of the present invention, Fig. 2 is a schematic diagram illustrating the teaching points and parameters necessary to calculate the segment shape equation, and Fig. 3 is a mold polishing method. A schematic diagram showing an example of a polishing device, FIG. 4 is a schematic block diagram showing an example of the configuration of a mold polishing device, FIG. 5 is a block diagram showing an embodiment of the mold polishing device of the present invention, and FIG. 8 are schematic diagrams showing the configuration of a conventional mold polishing device, and FIG. 9 is a schematic diagram illustrating a conventional mold polishing operation. (21)...Boundary data memory, (22)...Data memory for confirmation, (24)...Parameter memory for confirmation, (25)...
- Arithmetic unit, (28)...Robot motion control unit, (PI
) ~ (PI7)...Teaching point (A) Figure CB)

Claims (1)

[Claims] 1. To divide the mold surface into segments, teach each segment a plurality of points (P1) to (P5) for boundary setting, and determine the shape of each segment. The minimum required points (P6) to (P17) are taught and/or the parameters necessary to determine the shape of each segment are set, and the corresponding segment is The method is characterized in that the shape is calculated, and the robot arm is operated to press a polishing tool perpendicularly to the mold surface based on the calculated segment shape, preset polishing conditions, and set boundaries. Mold polishing method. 2. The mold polishing method according to claim 1, wherein the parameter identifies at least the type of shape. 3. Boundary data holding means (21) that holds teaching data of a plurality of points for boundary setting in correspondence with a plurality of segments constituting the mold surface, and a minimum number of points necessary to determine the shape of each segment. It has confirmation data holding means (22) (24) for holding teaching data of points and/or parameters necessary for deciding the shape of each segment, and also has confirmation data holding means (22) (24). ) and/or the teaching data held in
or a shape calculation means (25) that calculates the shape of the corresponding segment based on the setting parameters, and the shape of the calculated segment;
A control means (28) for operating a robot arm to press a polishing tool perpendicularly to the mold surface based on preset polishing conditions and preset boundaries. Mold polishing device.