JP4857861B2 - Cutting device and method thereof, method of calculating cutting radius of cutting blade, and method of manufacturing cut product - Google Patents

Description

  The present invention relates to a cutting apparatus and method for cutting a free-form surface by rotating a tool, a method for calculating a rotation radius of a cutting blade, and a method for manufacturing a cut product. More specifically, the present invention relates to a cutting device including an on-machine measuring device and a method thereof, a method of calculating a turning radius of a cutting blade, and a method of manufacturing a cut product.

  Conventionally, for example, a fly-cut type cutting device has been used as a method of creating a mold for molding an optical component having a free-form surface such as a mirror or a lens (see, for example, Patent Document 1). In a fly-cut cutting apparatus, for example, a workpiece to be cut is positioned in the XZ plane by an X-axis direction slide table and a Z-axis direction slide table. A cutting blade is attached to a spindle arranged in parallel to the Y axis, and is rotated about the rotation axis. As a result, the cutting edge of the cutting blade draws a circle. Cutting of one line is performed by controlling the movement of the workpiece by one line in the XZ plane so as to contact one place on the circumference drawn by the cutting blade. Next, the cutting blade is fed a predetermined distance in the Y-axis direction, and the next one line is cut.

  In such a cutting apparatus, it is necessary to accurately grasp the tool rotation radius, which is the distance from the rotation center at the tip of the cutting blade, for precise machining. Cutting blades gradually deteriorate due to wear. Wear slightly reduces the tool turning radius. Alternatively, the cutting blade is replaced when the degree of wear increases to a certain degree or the cutting edge is damaged. The tool turning radius does not exactly match before and after cutting blade replacement. Therefore, the tool turning radius of the cutting blade is obtained before machining. In general, a work for measurement is placed at a predetermined position on the slide table, and the tool is rotated once. Then, the workpiece is removed and the depth of the cutting trace is measured, thereby calculating the tool turning radius.

On the other hand, an on-machine measuring technique for measuring the shape of a workpiece or the like processed in this way with high accuracy while being placed on a slide table is disclosed (for example, see Patent Document 2). According to the measurement method described in this document, it is said that precise measurement can be performed with a small measurement pressure by suspending the probe head in the gas.
JP 2001-162426 A Republished WO00 / 52419

  However, in the above-described conventional cutting apparatus, it is inevitable that some errors occur when the measuring workpiece is attached or detached. Since the tool turning radius is the distance from the tool rotation center to the cutting edge tip, if there is an error in the mounting position of the measurement workpiece with respect to the tool rotation center, the depth of the cutting trace and the tool turning radius An error is included in the relationship between them. Therefore, there is a problem that the measurement result of the tool turning radius includes a certain amount of error. On-machine measurement technology measures the relative distance by contacting an object, and is not suitable for measuring a position where it cannot be directly touched, such as the center of rotation of a tool.

  The present invention has been made to solve the problems of the conventional cutting apparatus described above. In other words, the problem is to provide a cutting device and method capable of easily obtaining the tool turning radius and enabling precise machining, a method for calculating the turning radius of the cutting blade, and a method for manufacturing a cut product. There is to do.

  In order to solve this problem, the cutting device of the present invention includes an object support unit that supports a workpiece, a cutting blade rotating unit that rotates the cutting blade so that the cutting edge draws a circle around the axis, and A first moving unit that moves the object support unit and the cutting blade rotating unit to each other in the direction of the rotation axis of the cutting blade rotating unit; and a first moving unit that moves the object support unit and the cutting blade rotating unit to each other. Of the first moving unit, the second moving unit that moves in a direction that intersects and separates the machining surface of the workpiece and the cutting blade, and the object supporting unit and the cutting blade rotating unit. And a third moving part that moves in a direction intersecting the moving direction and the moving direction of the second moving part. While moving by the third moving part, the cutting blade is rotated by the cutting blade rotating part, Cutting a workpiece by scraping a part of the machined surface of the workpiece. A cutting device to be machined, which is provided on the same side as the cutting blade rotating part with respect to the movement by the first to third moving parts, and whose tip is in contact with the object surface of the object to be processed supported by the object supporting part. By measuring the position of the contact point in the moving direction of the second moving unit, and the position of the tip of the measuring unit in the retracted state with respect to the position of the rotation axis of the cutting blade rotating unit, The relative position storage unit for storing the relative position in the moving direction of the second moving unit, and the bottom of the cutting trace when the target surface of the workpiece supported by the target support unit is cut once with a cutting blade The cutting trace measuring unit that measures with the measuring instrument and obtains the indicated value, the indicated value obtained by the cutting trace measuring unit, stored in the retracted state of the on-machine measuring instrument, and the relative position storage unit The cutting blade rotating part is subtracted from the relative position A turning radius calculation unit that calculates the turning radius of the cutting edge of the cutting blade, and an actual machining control unit that determines the amount of movement of the second moving unit during actual machining based on the turning radius calculated by the turning radius calculation unit; It is what has.

  According to the cutting device of the present invention, the object support part that supports the object to be processed and the cutting blade rotating part that rotates the cutting blade are mutually connected to the first moving part, the second moving part, and the third moving part. Moved by part. Further, an on-machine measuring instrument is provided on the same side as the cutting blade rotating part with respect to the movement of these moving parts. And the bottom part of the cutting trace attached to the workpiece by the cutting blade rotating part is measured by the on-machine measuring instrument. From the difference between the indicated value at this time and the indicated value in the retracted state of the on-machine measuring instrument, the distance to the cutting edge position of the cutting blade based on the position of the on-machine measuring instrument in the retracted state is obtained. Further, according to the present invention, the relative position storage unit stores the relative position in the moving direction of the second moving unit with respect to the position of the rotation axis of the cutting blade rotating unit in the retracted state of the on-machine measuring instrument. Yes. Accordingly, the cutting edge position of the cutting blade with respect to the position of the rotation axis of the cutting blade rotation part, that is, the rotation radius of the cutting edge of the cutting blade by the cutting blade rotation part is calculated. Thereby, the tool turning radius can be easily obtained.

  Furthermore, the present invention extends to a method for calculating the rotation radius of a cutting blade by using the cutting apparatus of the present invention to obtain the rotation radius of the cutting edge of the cutting blade in the same manner. Further, the present invention extends to a cutting method in which cutting is performed using the rotation radius of the cutting edge of the obtained cutting blade. Furthermore, it extends to a manufacturing method of a cut product manufactured by the cutting method. It should be noted that a molded product molded by a mold manufactured by this manufacturing method is also included in a product manufactured by this manufacturing method.

  According to the cutting device and method of the present invention, the method for calculating the radius of rotation of a cutting blade, and the method for manufacturing a cut product, the tool rotation radius can be easily obtained, and precise machining is possible.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the best mode for embodying the present invention will be described in detail with reference to the accompanying drawings. In this embodiment, the present invention is applied to a fly-cut processing machine that processes a free-form surface by cutting.

  As shown in FIG. 1, the fly-cut processing machine 1 of the present embodiment is provided with an X-axis direction slide table 12 and a Z-axis direction slide table 13 that are stacked on a surface plate 11. Furthermore, the surface plate 11 is provided with a Y-axis direction slide table 14 along with these. A tool spindle 15 is attached to the Y-axis direction slide table 14. A cutting blade 16 is attached to the outer peripheral surface of the tip of the tool spindle 15.

  Each of the axial slide tables 12, 13, and 14 is controlled to move in the respective axial direction, and the tool spindle 15 is controlled to rotate so that the cutting blade 16 rotates about its main axis. As these slide tables 12, 13, and 14, those having an accuracy of position control of 0.01 μm or less are used. The main spindle of the tool spindle 15 is always provided parallel to the Y axis. Here, the Y-axis direction slide table 14 corresponds to the first moving unit, the Z-axis direction slide table 13 corresponds to the second moving unit, and the X-axis direction slide table 12 corresponds to the third moving unit. Of these, the X-axis direction slide table 12 and the Z-axis direction slide table 13 that support the workpiece W correspond to the object support portion. The tool spindle 15 corresponds to the cutting blade rotating part.

  According to the fly-cut processing machine 1, as shown in FIG. 1, the workpiece W placed on the Z-axis direction slide table 13 is moved by the X-axis direction slide table 12 and the Z-axis direction slide table 13. It is arranged at a predetermined position in the −Z plane. The workpiece W can be controlled to move in the XZ plane at a predetermined speed. Further, the position of the cutting blade 16 is controlled in the Y-axis direction by the Y-axis direction slide table 14. Further, the cutting blade 16 is rotated around the main axis at a predetermined rotational speed by the tool spindle 15. Thereby, the front-end | tip part of the cutting blade 16 draws a circle.

  In this embodiment, the cutting blade 16 and the workpiece W are relatively brought close to each other, and the cutting blade 16 is rotated by the tool spindle 15 to cut the workpiece W. That is, by disposing the workpiece W so as to contact the cutting blade 16 at one place on the circumference drawn by the cutting edge of the cutting blade 16, the cutting edge scrapes off the workpiece W at the contacted location. The cut portion is the cutting portion, and the surface of the workpiece W where the cutting portion is formed is the cutting surface. For example, in FIG. 1, the surface on the back left side of the workpiece W is a cutting surface. Then, the cutting surface of the workpiece W is cut toward the right front side in the Z-axis direction by coming into contact with the cutting blade 16. This right-front direction in the Z-axis direction in the cutting depth direction is also referred to as a cutting direction.

  Furthermore, the fly-cut processing machine 1 of this embodiment has an on-machine measuring device 21. As shown in FIG. 1, the on-machine measuring device 21 is attached to the Y-axis direction slide table 14 and moved in the Y-axis direction together with the tool spindle 15. The relative positional relationship between the tool spindle 15 and the on-machine measuring device 21 is fixed. Further, the probe 22 which is the distal end portion of the on-machine measuring device 21 is urged toward the right front side in FIG. 1, and is advanced and retracted in the Z-axis direction in contact with the measurement target. That is, the measuring direction of the on-machine measuring device 21 is the Z-axis direction, which is parallel to the cutting direction of the fly-cut processing machine 1.

  The probe 22 of the on-machine measuring device 21 according to the present embodiment is retracted so that the tip thereof is not in contact with the workpiece W or the like except during measurement. Processing on the workpiece W is performed in this retracted state. The indicated value of the on-machine measuring device 21 in this retracted state is A. The indicated value of the on-machine measuring device 21 indicates a distance from a predetermined unknown origin. In general, the magnitude of the measurement direction of the object is obtained from the difference between the indicated values of the two measurement results. The on-machine measuring device 21 has a small urging force, sliding resistance, inertia and the like of the probe 22 and has good followability to the cutting surface of the workpiece W. Therefore, the amount of displacement from the origin can be measured accurately.

  Further, in this embodiment, the distances in the X-axis direction and the Z-axis direction between the tip of the probe 22 in the retracted state and the rotation center of the tool spindle 15 are measured in advance in advance. Here, the distance in the X-axis direction is distance S, and the distance in the Z-axis direction is distance P. By this measurement, the distances S and P are known values below. The on-machine measuring device 21 is arranged in the Y-axis direction so that the origin of the probe 22 is slightly above the cutting edge of the cutting blade 16 in FIG.

  Furthermore, in this embodiment, as shown in FIG. The control unit 25 controls the X-axis direction slide table 12, the Z-axis direction slide table 13, the Y-axis direction slide table 14, and the tool spindle 15. Further, the tool turning radius R is obtained based on the measurement result of the on-machine measuring device 21. Note that the X coordinate, the cutting depth (Z coordinate), and the like of the cutting position with respect to the workpiece W are set based on the tool rotation center (O in FIG. 4) of the tool spindle 15.

  In the fly-cut processing machine 1 of the present embodiment, the current tool rotation radius R of the cutting blade 16 is accurately obtained using the measurement work prior to cutting the work W. This is because the cutting blade 16 may be deteriorated due to wear or the like, and is replaced when the deterioration becomes severe, so that the tool turning radius also changes. Therefore, first, the measurement workpiece W1 is fixed at a predetermined position on the Z-axis direction slide table 13. Then, a predetermined cutting depth is designated and the fly cutting machine 1 is instructed to cut the measuring workpiece W1 only once.

  That is, the axial slide tables 12, 13, and 14 are controlled to bring the measuring workpiece W1 and the cutting blade 16 of the tool spindle 15 close to a predetermined distance, and the tool spindle 15 is rotated once. As a result, one cut mark by the cutting blade 16 is created on the workpiece W. The indicated value for the depth of cut must be so small that it is reasonable for a single cut.

  Next, the X-axis direction slide table 12 is driven to move the measurement workpiece W <b> 1 so that the created cutting traces face the on-machine measuring device 21. That is, the X-axis direction slide table 12 is moved forward in the left direction in FIG. 1 by the X-axis direction distance (distance S) between the rotation center of the tool spindle 15 and the tip of the probe 22 of the on-machine measuring device 21. At this time, the Z-axis direction slide table 13 and the Y-axis direction slide table 14 do not move. Further, since the probe 22 is in the retracted state, it does not come into contact with the measurement workpiece W1.

  Next, the probe 22 of the on-machine measuring device 21 is projected until it comes into contact with the workpiece W1, and the measurement state is set. As a result, the tip of the probe 22 is disposed at the same position as the deepest position of the cutting trace in the X-axis direction, and is disposed slightly above the deepest position of the cutting trace in the Y-axis direction. And the probe 22 will be in the state urged | biased toward the cutting trace of the workpiece | work W1 for a measurement. Next, as shown in FIG. 3, the displacement of the indicated value of the on-machine measuring device 21 is acquired while driving the Y-axis direction slide table 14 from top to bottom. Then, as the extreme value of the indicated value of the on-machine measuring device 21 due to the movement of the Y-axis direction slide table 14, the indicated value at the deepest part of the cutting trace is obtained. The indicated value at the bottom of this cutting mark is B.

  If there is no cutting trace, that is, if the cutting blade 16 is swung with respect to the workpiece W, the X-axis direction slide table 12 is driven again to return to the previous cutting position, and the cutting depth is adjusted. Increase the indicated amount slightly and try again. Further, when the probe 22 is in a measurement state, as shown in FIG. 3, the tip of the probe 22 may be arranged above the deepest position of the cutting trace inside the cutting trace. In this way, the moving distance of the Y-axis direction slide table 14 for obtaining the instruction value B is extremely small, so that measurement can be performed in a short time.

Next, the positional relationship in the Z-axis direction between the indicated values A and B of the on-machine measuring device 21 and the tool spindle 15 is compared and shown in FIG. As shown in this figure, the tool rotation radius R is equal to the distance from the tool rotation center O at the deepest position of the cutting trace actually cut. The distance indicated by C in the figure is obtained from the indicated value A of the on-machine measuring device 21 in the retracted state and the indicated value B obtained by scanning the cutting trace as described above. This is the sum of the tool rotation radius R and P (the distance in the Z-axis direction between the tip of the retracted probe 22 and the rotation center of the tool spindle 15) as shown in FIG. Therefore, the tool turning radius R is obtained by the following equation.
R = C−P = | A−B | −P
In FIG. 4, the relationship between the position of the origin of the probe 22, the tool rotation center O, and the tool rotation radius R is simply compared and focused on only the Z-axis direction.

  When the measurement is completed, the workpiece W1 for measurement is removed, and the workpiece W to be actually processed is fixed at a predetermined position. Then, the Z-axis direction slide table 13 is controlled using the obtained tool rotation radius R, and the workpiece W is cut. That is, the tool spindle 15 is rotated while moving the workpiece W in the XZ plane. For example, one line of cutting is performed while moving the X-axis direction slide table 12 from the right back to the left front in FIG. At the same time, the Z-axis direction slide table 13 is also controlled in accordance with the cutting surface shape. When the cutting of one line is completed, the cutting blade 16 is once separated from the workpiece W, the cutting blade 16 is moved by a predetermined amount in the Y-axis direction, and the workpiece W is returned to the right back position. Then, the cutting blade 16 and the workpiece W are brought into contact again to perform the next one-line cutting. By repeating this, a processed surface having a desired shape is obtained.

  As described above in detail, according to the fly-cut processing machine 1 of this embodiment, the cutting depth is measured while the measurement workpiece W1 is fixed, and the tool rotation radius R is obtained. Measurements that do not include mounting position errors are possible. Therefore, the tool turning radius can be easily obtained, and precise machining is possible.

  In addition, this form is only a mere illustration and does not limit this invention at all. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof. For example, although the on-machine measuring device 21 is disposed above the cutting blade 16, the same measurement can be performed by scanning upward from below as the lower side. In addition, it is possible to obtain a cut product by machining the measured workpiece as it is without distinguishing between the workpiece for measurement and the actual workpiece. In this case, a cutting trace smaller than the cutting depth required for actual machining may be made at the location where cutting is actually performed, and measurement may be performed in the same manner as described above. In this way, this cutting trace does not affect the subsequent processing.

It is a perspective view which shows schematic structure of the fly cut processing machine which concerns on this form. It is a block diagram which shows the control relationship of a fly cut processing machine. It is explanatory drawing which shows the measuring method by an on-machine measuring device. It is explanatory drawing which shows the comparison condition of each value of a Z-axis direction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fly cut processing machine 12 X-axis direction slide table 13 Z-axis direction slide table 14 Y-axis direction slide table 15 Tool spindle 16 Cutting blade 21 On-machine measuring device 25 Control part

Claims (4)

An object support for supporting the workpiece;
A cutting blade rotating part for rotating the cutting blade so that the cutting edge draws a circle around the axis;
A first moving part that moves the object support part and the cutting blade rotating part to each other in the direction of the rotation axis of the cutting blade rotating part;
A second moving unit that moves the object support unit and the cutting blade rotation unit in a direction that intersects the moving direction of the first moving unit and moves the processing surface of the processing object and the cutting blade closer to and away from each other. When,
A third moving part that moves the object support part and the cutting blade rotating part to each other in a direction crossing the moving direction of the first moving part and the moving direction of the second moving part;
In a cutting apparatus for cutting a workpiece by rotating a cutting blade by the cutting blade rotating portion and scraping a part of a processing surface of the workpiece with the blade edge while moving by the third moving portion. ,
The movement by the first to third moving parts is provided on the same side as the cutting blade rotating part, and the tip is brought into contact with the target surface of the workpiece supported by the target object supporting part. An on-machine measuring instrument for measuring the position of the second moving part in the moving direction;
A relative position storage unit for storing a relative position in a moving direction of the second moving unit with respect to a position of a rotation axis of the cutting blade rotating unit at a tip position in the retracted state of the on-machine measuring device;
A cutting trace measuring unit that measures the bottom of a cutting trace when the target surface of the workpiece supported by the target supporting unit is cut once by a cutting blade with the on-machine measuring instrument and obtains the indicated value; ,
By subtracting the instruction value in the retracted state of the on-machine measuring instrument and the relative position stored in the relative position storage unit from the instruction value acquired by the cutting trace measuring unit, the cutting blade rotating unit A turning radius calculator for calculating the turning radius of the cutting edge of the cutting blade;
A cutting apparatus comprising: an actual machining control unit that determines a movement amount of the second moving unit during actual machining based on the rotation radius calculated by the rotation radius calculation unit. An object support for supporting the workpiece;
A cutting blade rotating part for rotating the cutting blade so that the cutting edge draws a circle around the axis;
A first moving part that moves the object support part and the cutting blade rotating part to each other in the direction of the rotation axis of the cutting blade rotating part;
A second moving unit that moves the object support unit and the cutting blade rotation unit in a direction that intersects the moving direction of the first moving unit and moves the processing surface of the processing object and the cutting blade closer to and away from each other. When,
A third moving part that moves the object support part and the cutting blade rotating part to each other in a direction crossing the moving direction of the first moving part and the moving direction of the second moving part;
In a cutting apparatus for cutting a workpiece by rotating a cutting blade by the cutting blade rotating portion and scraping a part of a processing surface of the workpiece with the cutting edge while moving by the third moving portion In the method of calculating the turning radius of the cutting blade,
The movement by the first to third moving parts is provided on the same side as the cutting blade rotating part, and the tip is brought into contact with the target surface of the workpiece supported by the target object supporting part. Using an on-machine measuring instrument for measuring the position of the second moving part in the moving direction,
Measuring the relative position in the moving direction of the second moving part with respect to the position of the rotational axis of the cutting blade rotating part in the retracted state of the on-machine measuring instrument;
Measuring the bottom of the cutting trace when the target surface of the processing target supported by the target support is cut once with a cutting blade, and obtaining the indicated value;
The radius of rotation of the cutting edge of the cutting blade by the cutting blade rotating portion is calculated by subtracting the instruction value in the retracted state of the on-machine measuring instrument and the previously measured relative position from the acquired instruction value. The calculation method of the turning radius of the cutting blade. An object support for supporting the workpiece;
A cutting blade rotating part for rotating the cutting blade so that the cutting edge draws a circle around the axis;
A first moving part that moves the object support part and the cutting blade rotating part to each other in the direction of the rotation axis of the cutting blade rotating part;
A second moving unit that moves the object support unit and the cutting blade rotation unit in a direction that intersects the moving direction of the first moving unit and moves the processing surface of the processing object and the cutting blade closer to and away from each other. When,
A third moving part that moves the object support part and the cutting blade rotating part to each other in a direction crossing the moving direction of the first moving part and the moving direction of the second moving part;
In a cutting method of cutting a processing object by rotating a cutting blade by the cutting blade rotating unit and scraping a part of a processing surface of the processing object at the cutting edge while moving by the third moving unit. ,
The movement by the first to third moving parts is provided on the same side as the cutting blade rotating part, and the tip is brought into contact with the target surface of the workpiece supported by the target object supporting part. Using an on-machine measuring instrument for measuring the position of the second moving part in the moving direction,
Measuring the relative position in the moving direction of the second moving part with respect to the position of the rotational axis of the cutting blade rotating part in the retracted state of the on-machine measuring instrument;
Measuring the bottom of the cutting trace when the target surface of the processing target supported by the target support is cut once with a cutting blade, and obtaining the indicated value;
By subtracting the instruction value in the retracted state of the on-machine measuring instrument from the acquired instruction value and the relative position measured in advance, the rotation radius of the cutting edge of the cutting blade by the cutting blade rotating part is calculated,
The cutting method characterized by determining the movement amount of the said 2nd moving part at the time of an actual process based on the calculated turning radius. An object support for supporting the workpiece;
A cutting blade rotating part for rotating the cutting blade so that the cutting edge draws a circle around the axis;
A first moving part that moves the object support part and the cutting blade rotating part to each other in the direction of the rotation axis of the cutting blade rotating part;
A second moving unit that moves the object support unit and the cutting blade rotation unit in a direction that intersects the moving direction of the first moving unit and moves the processing surface of the processing object and the cutting blade closer to and away from each other. When,
A third moving part that moves the object support part and the cutting blade rotating part to each other in a direction crossing the moving direction of the first moving part and the moving direction of the second moving part;
A cutting workpiece that cuts the workpiece by rotating the cutting blade by the cutting blade rotating portion and scraping a part of the machining surface of the workpiece with the blade edge while moving by the third moving portion. In the manufacturing method,
The movement by the first to third moving parts is provided on the same side as the cutting blade rotating part, and the tip is brought into contact with the target surface of the workpiece supported by the target object supporting part. Using an on-machine measuring instrument for measuring the position of the second moving part in the moving direction,
Measuring the relative position in the moving direction of the second moving part with respect to the position of the rotational axis of the cutting blade rotating part in the retracted state of the on-machine measuring instrument;
Measuring the bottom of the cutting trace when the target surface of the processing target supported by the target support is cut once with a cutting blade, and obtaining the indicated value;
By subtracting the instruction value in the retracted state of the on-machine measuring instrument from the acquired instruction value and the relative position measured in advance, the rotation radius of the cutting edge of the cutting blade by the cutting blade rotating part is calculated,
A method for manufacturing a cut workpiece, wherein the amount of movement of the second moving portion during actual machining is determined based on the calculated turning radius.

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