JP2010194678A - Machining device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a machining device using a grinding wheel, which prevents a product defect due to change over time in shape of the grinding wheel or the like. <P>SOLUTION: The machining device M1 performs centering and edging of an optical element 101 with the grinding wheel 106 when the optical element 101 is rotated while being held between a fixed holder 102 of a fixed-side work spindle 120 and a movable side holder 103 of a movable-side work spindle 130. The fixed-side work spindle 120 is provided with a dressing wheel 104 and a camera 105 for recognizing an appearance shape of the grinding wheel 106. A control part 140 of the machining device M1 allows the dressing wheel 104 to occasionally correct the appearance shape of the grinding wheel 106 recognized through the camera 105, and grind an outer peripheral part 101a of the optical element 101, so that the product defect due to the change with time in the shape of the grinding wheel 106 or the like is prevented. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a processing apparatus.

For example, in a processing apparatus that uses a grindstone as a processing tool, truing for correcting the shape of a grindstone that wears during processing is performed.
For example, in Patent Document 1, a grindstone correcting device and a contact detection device whose positions are fixed are arranged on the side of a head stock for holding and rotating a workpiece, and a grindstone table side on which a grind wheel is mounted and moved Has a touch sensor.

  Prior to truing, the grinding wheel is brought into contact with the detection pin of the contact detection device to detect the position of the grinding wheel, thereby positioning the grinding wheel with respect to the grinding wheel correcting device to execute truing.

  In this case, since the detection pin of the contact detection device is worn by contact with the grinding wheel, the detection pin of the touch detection device is periodically brought into contact with the detection pin of the contact detection device so that the detection pin is in contact with the detection pin. The truing of the grinding wheel is corrected by correcting the cutting amount of the grinding wheel with respect to the grinding wheel correcting device in the truing by the amount of wear.

  Further, in Patent Document 2, in a lens centering device for processing by contacting a grindstone with the outer periphery of a rotating lens that is sandwiched between lens holders, a piezoelectric cutting dynamometer is disposed on a spindle that supports the grindstone. In addition, a technique for optimizing the cutting amount of the grindstone and the rotation speed of the lens is disclosed based on the correlation between the grinding resistance value obtained from the piezoelectric cutting dynamometer and the quality of the lens after grinding.

However, the technique of the former Patent Document 1 has the following technical problems.
First, after grinding a preset number of workpieces, the grindstone is regularly corrected (truing) regardless of whether the grindstone is worn or not. Therefore, the grindstone is corrected even when it is not worn at all, and the maintenance time becomes longer than necessary, and the grindstone is severely deteriorated due to the unnecessary grindstone correction, which is uneconomical.

  Secondly, the grindstone can be periodically corrected, but the device cannot grasp the actual deterioration state of the grindstone. For this reason, if the grindstone is greatly damaged due to some influence, product defects resulting from the grindstone shape defect continue to be produced until the regular grindstone correction time comes.

  Thirdly, in order to prevent a product defect due to sudden damage of the grindstone, it is necessary to visually confirm the grindstone, but an artificial inspection is interposed, which is inefficient. In the method of visually inspecting the abrasion of the grindstone, the judgment of good or bad becomes ambiguous, stable production is difficult, and judgment skills that require skill are required.

On the other hand, the latter patent document 2 has the following technical problems.
First, as in the case of Patent Document 1 described above, the apparatus cannot grasp the wear state of the grindstone in a timely manner.

Secondly, it is possible to grasp the deterioration of the grinding state from the fluctuation of the grinding resistance and prompt the replacement of the grindstone, but there is no function for automatically correcting the grindstone.
Third, it is possible to grasp the occurrence of product defects to some extent from the deterioration of the state during grinding detected by the fluctuation of grinding resistance during processing. However, it cannot be grasped that the grindstone has deteriorated before processing. For this reason, it is impossible to prevent a product defect due to a defective shape of the grindstone.

  Fourthly, although the state of the grindstone being processed can be indirectly known from the grinding resistance acting on the spindle of the grindstone, the apparatus cannot automatically correct the grindstone. Further, it is necessary to manually calculate the shape correction value of the grindstone, which is difficult to correct and requires skill and time.

JP-A-9-70755 JP 2000-84814 A

  An object of the present invention is to prevent the occurrence of product defects due to a change in the shape of a grindstone over time in a processing apparatus using a grindstone.

The present invention comprises a clamping means for holding and rotating a workpiece,
A first grindstone that abuts on the workpiece and performs grinding or polishing;
A stage for moving the mounted first whetstone;
A second grindstone that is arranged in a movable range of the first grindstone by the stage and is used to correct the first grindstone;
Recognition means for recognizing the shape of the first grindstone;
Control means for correcting the first grindstone using the second grindstone based on the shape of the first grindstone;
Provided is a processing apparatus.

  ADVANTAGE OF THE INVENTION According to this invention, generation | occurrence | production of the product defect resulting from the shape change of a grindstone with time, etc. can be prevented in the processing apparatus using a grindstone.

It is a top view which shows an example of a structure of the processing apparatus which is one embodiment of this invention. It is explanatory drawing explaining an example of the shape of the grindstone used in the processing apparatus which is one embodiment of this invention. It is a conceptual diagram explaining the effect | action of the processing apparatus which is one embodiment of this invention. It is a flowchart explaining the effect | action of the processing apparatus which is one embodiment of this invention. It is a top view which shows the structural example of the processing apparatus which is other embodiment of this invention.

  In the first aspect of the present embodiment, the optical element grinding apparatus is provided with a correction grindstone for correcting the grindstone for processing, and before grinding, the shape and state of the grindstone used for grinding the optical element are set in the camera. When the grindstone is worn and recognized, the mechanism for automatically correcting the grindstone using the correcting grindstone is exemplified.

  In the second aspect of the present embodiment, wear at the corners of the grindstone is recognized by photographing with a camera. When chamfering the corners of the optical element, chamfering is performed using the corners of the concave shaped grindstone. This processing causes wear of the corners of the grindstone.

  In the second aspect, the shape of the corner portion of the grindstone is photographed and recognized at the same timing as the grindstone recognition process in the first aspect described above. Thereby, it is possible to immediately detect the abnormality of the grindstone.

  In the third aspect of the present embodiment, wear or breakage of the grindstone is detected in the second aspect described above. Based on this detection result, the correction amount of the grindstone is automatically calculated. When correction is necessary, the grindstone surface is automatically corrected with the grindstone for correction, and the worn or damaged portion of the grindstone is scraped off.

  In the fourth aspect of the present embodiment, in the third aspect described above, wear or breakage of the corner portion of the grindstone is detected. Based on this detection result, the correction amount of the grindstone is automatically calculated, and when correction is necessary, the corner portion of the grindstone is automatically corrected with the grindstone for correction.

  In the fifth aspect of the present embodiment, the position of the grindstone calculated by image recognition by the camera is added to the cutting amount when the optical element is actually ground by the grindstone, thereby changing the shape due to wear of the grindstone. High-precision grinding is possible without being affected by the above.

In the sixth aspect of the present embodiment, the wear of the grindstone is automatically recognized by image recognition by a camera, and a warning notification of the grindstone replacement time is automatically given to the user.
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a plan view showing an example of the configuration of a processing apparatus according to an embodiment of the present invention.
FIG. 2 is an explanatory view for explaining an example of the shape of a grindstone used in a processing apparatus according to an embodiment of the present invention.

FIG. 3 is a conceptual diagram for explaining the operation of the machining apparatus according to one embodiment of the present invention.
FIG. 4 is a flowchart for explaining the operation of the machining apparatus according to one embodiment of the present invention.
(Constitution)
The structure of the processing apparatus M1 of this Embodiment is demonstrated with reference to FIG.

In FIG. 1, description will be made assuming that the left-right direction is the X direction, the up-down direction is the Y direction, and the direction perpendicular to the paper surface is the Z direction. As an example, the Z direction is the vertical direction, and the XY plane is the horizontal plane.
In the processing apparatus M1 of the present embodiment, the fixed-side work spindle 120 and the movable-side work spindle 130 are arranged so as to be substantially coaxially opposed in the X direction, and the processing apparatus M1 is connected via a bearing 121 and a bearing 131, respectively. It is rotatably supported by a housing (not shown).

  In this case, the X-direction displacement of the fixed work spindle 120 is fixed, and a cup-shaped fixed holder 102 (clamping means) having a concave cross section is fixed to the end facing the movable work spindle 130.

  On the other hand, the movable work spindle 130 is movably provided in the X direction (parallel to the rotation axis) with respect to the housing of the processing apparatus M1, and a movable holder is provided at the opposite end to the fixed work spindle 120. 103 (clamping means) is fixed.

The fixed work spindle 120 and the movable work spindle 130 are rotationally driven by a motor (not shown).
The optical element 101 (work) is sandwiched between the edge portion 102a of the fixed holder 102 and the edge portion 103a of the movable side holder 103 and pressed from the movable side work spindle 130 side, so-called bell clamp type. Centering is performed, and an optical axis (not shown) of the optical element 101 is clamped coaxially with the fixed work spindle 120 and the movable work spindle 130.

  Note that, as a method of fixing the optical element 101 at the time of the above-described centering, the fixed holder 102 is temporarily held by vacuum suction, and the movable side holder 103 is approached and clamped and fixed. The optical element 101 can be fixed by another means. For example, a method in which the optical element 101 is bonded and fixed to the fixing holder 102 is also possible.

  In the case of the present embodiment, a correction grindstone 104 (second grindstone) is installed on the fixed work spindle 120 which is the same as the fixed holder 102. With the rotation of the fixed work spindle 120, the fixed holder 102 and the correction grindstone 104 are configured to rotate simultaneously.

The correction grindstone 104 is fixed to the fixed work spindle 120 so as to be replaceable. The correction grindstone 104 is a worn product and is replaced as necessary.
A grindstone spindle 107 for driving the grindstone 106 (first grindstone) is located in a bearing 107d at a position adjacent to the opposing fixed work spindle 120 and movable work spindle 130 in the Y direction (perpendicular to the rotation axis). There is provided a grindstone positioning stage 110 (stage) mounted via the.

  The grindstone positioning stage 110 includes an X movement table 108 on which the grindstone spindle 107 is placed, and a Y movement table 109 on which the X movement table 108 is mounted.

  The X movement table 108 is moved in the X direction by the X stage movement motor 108a, and the Y movement table 109 is moved in the Y direction by the Y stage movement motor 109a.

  The grindstone 106 is fixed to one end of a grindstone spindle 107 protruding from the end edge of the X moving table 108 to the minus side in the X direction by screws or the like. Since the grindstone 106 is a worn product, it is replaced as necessary.

In the grindstone spindle 107 that is rotatably supported via the bearing 107d, a pulley 107c is fixed to the end opposite to the grindstone 106.
A grinding wheel motor 107a is mounted on the X moving table 108 at a position adjacent to the grinding wheel spindle 107 in the Y direction, and a belt 107b is stretched between the grinding wheel motor 107a and the pulley 107c.

Thereby, the grindstone 106 fixed to the grindstone spindle 107 is rotationally driven by the grindstone motor 107a.
In the case of the processing apparatus M1 of the present embodiment, a camera 105 (recognizing means) for taking an image of the grindstone 106 is provided.

  In the case of the present embodiment, since the grindstone 106 moves relative to the camera, the position of the camera 105 is fixed. Conversely, when the position of the camera 105 needs to be corrected according to the position of the grindstone 106, the camera 105 Position control may be performed by installing 105 on an XYZ stage (not shown).

  The grindstone 106 supported by the X moving table 108 of the grindstone positioning stage 110 via the grindstone spindle 107 operates the X stage moving motor 108a and the Y stage moving motor 109a to displace the X moving table 108 and the Y moving table 109. As a result, the grindstone positioning stage 110 moves to an arbitrary position within the movable range.

  In the case of the present embodiment, the moving position of the grindstone 106 is the position where the camera 105 photographs the grindstone 106, the position where the optical element 101 is ground with the grindstone 106, the position where the wear of the grindstone 106 is corrected with the correcting grindstone 104, There are three places.

  The processing apparatus M1 of the present embodiment is provided with a control unit 140 (control means) configured by a computer, for example. The control unit 140 controls an X stage moving motor 108a, a Y stage moving motor 109a, a grindstone motor 107a, and a motor (not shown) for driving the fixed work spindle 120 and the movable work spindle 130 of the grindstone positioning stage 110. Thus, the overall operation of the processing apparatus M1 is controlled.

Further, the control unit 140 has a function of processing an image photographed by the camera 105 as described later.
In the case of the present embodiment, these control functions of the control unit 140 are realized by a control program 141 installed in the control unit 140.

FIG. 2 is an explanatory diagram showing an example of the shape of the outer peripheral portion that performs the processing action of the grindstone 106 used in the processing apparatus M1 of the present embodiment.
The grindstone 106 of the present embodiment includes a grindstone surface 106a composed of a flat cylindrical surface at the center and a flange portion 106c composed of a large-diameter cylindrical surface provided so as to sandwich the grindstone surface 106a.

Between the grindstone surface 106a and the flanges 106c provided on both sides thereof, a grindstone angular surface 106b forming a conical surface (slope) is provided.
In the case of the present embodiment, for example, grinding of the outer peripheral portion 101a for centering the optical element 101 is performed using the grindstone surface 106a at the center of the outer periphery of the grindstone 106, and the chamfering of the optical element 101 is performed. The processing of the portion 101b is performed using the grindstone angular face 106b of the grindstone 106.

  The grindstone 106 is worn and changed in shape by the centering process and the chamfering process of the optical element 101. In this embodiment, as described later, the grindstone surface 106a and the grindstone square surface of the grindstone 106 are used. The controller 140 automatically recognizes changes in the shapes of the 106b and the flange 106c using the camera 105 and corrects them using the correction grindstone 104.

With reference to FIG. 3, an example of image processing used for recognition of the grindstone 106 by the camera 105 of the present embodiment will be described.
In this case, the camera 105 captures an image of the grindstone 106 from an oblique direction, and obtains an image of the contour shape of the outer peripheral portion of the grindstone 106 (the grindstone surface 106a, the grindstone square surface 106b, the flange 106c, etc.).

  When analyzing the image of the grindstone 106 obtained by the camera 105, as an example, the grindstone 106 is recognized by recognizing the locations of the grindstone angle part recognition range 202 (grindstone angle surface 106b) and the grindstone surface recognition range 203 (grindstone surface 106a). This is used to determine the contour position.

  In the image analysis of the grindstone angle part recognition range 202 (grindstone face 106b), the grindstone face 106b is in a range from the boundary between the grindstone face 106b and the flange 106c to the border between the grindstone face 106b and the grindstone face 106a. An imaging range capable of recognizing the entire area is required.

  In the image analysis of the grindstone surface recognition range 203 that is the grindstone surface 106a, a range from end to end of the grindstone surface 106a (that is, a range to the boundary between the grindstone surface 106a and the grindstone angular surface 106b located on both sides thereof) It is necessary to be able to recognize the grindstone wear 204 and the grindstone wear groove 205 on the grindstone surface 106a.

  Image analysis of the grindstone 106 requires prior preparation, and the state of the grinding grindstone 200 that has not been ground is first registered (stored) in a storage unit (not shown) provided in the control unit 140 and obtained from the grindstone 106 after grinding. Analyzing the misalignment in image recognition, and grasping the wear state.

  As another recognition method, an image of the entire circumference of the grindstone 106 can be acquired and recognized. In this case, a camera is installed at a position where the entire grinding surface of the grindstone 106 can be recognized, and, for example, four images are acquired for each 90-degree feed angle of rotation of the grindstone 106. As a result, the entire circumference of the grindstone 106 can be recognized, and the control unit 140 can monitor the detailed wear state of the surface of the grindstone 106, and can further accurately recognize the shape of the grindstone 106. it can.

(Function)
(1) Automatic correction operation of the grindstone 106 First, immediately after the new grindstone 106 is mounted, the control unit 140 registers the initial position of the grindstone 106 as a preparation setting.

That is, the control unit 140 drives the X stage moving motor 108 a and the Y stage moving motor 109 a to move the grindstone 106 to a position within the shootable range of the camera 105.
At this time, the grindstone motor 107a that drives the grindstone 106 via the grindstone spindle 107 is stopped at the origin position, and the grindstone 106 is not rotated.

  The control unit 140 captures the stationary grindstone 106 with the camera 105, acquires an image indicating the state of the unused grindstone 106 before grinding, recognizes the contour position of the grindstone 106, and sets the initial position (initial shape). ).

  Here, in the image of the grindstone 106, the control unit 140 indicates that, for example, if there is an abnormality in the shape and position of the two points of the grindstone angle part recognition range 202 and the grindstone surface recognition range 203, a production failure occurs. Notify users of warnings.

  In the present embodiment, the abnormality of the grindstone 106 is determined by the control unit 140 that the grindstone 106 may be partially scraped by grinding and an uneven surface may be formed on the outer peripheral portion 101a of the optical element 101 to be processed. When the control unit 140 determines that the grindstone 106 is partially ground by grinding, or when the control unit 140 determines that the grindstone 106 is unable to exhibit the grinding ability due to excessive grinding, the grindstone of the grindstone 106 When the control unit 140 determines that the corner surface 106b has been damaged, etc.

  When determining that there is no abnormality in the grindstone 106, the control unit 140 drives the X stage moving motor 108 a and the Y stage moving motor 109 a of the grindstone positioning stage 110 and is clamped between the fixed holder 102 and the movable side holder 103. It moves to the position of the optical element 101 in the closed state.

Then, the control unit 140 activates the grindstone motor 107a to rotate the grindstone 106.
At the same time, the controller 140 rotates the fixed work spindle 120 of the fixed holder 102 and the movable work spindle 130 of the movable holder 103 holding the optical element 101 from both sides.

  The optical element 101 is held in advance so that the optical axis of the optical element 101 coincides with the rotation center of the fixed-side work spindle 120 and the movable-side work spindle 130 by bell clamp type centering.

  In this state, the control unit 140 slightly finely moves the grindstone positioning stage 110 in the X and Y directions to bring the grindstone surface 106a of the outer peripheral portion of the grindstone 106 into contact with the outer peripheral portion 101a of the optical element 101. A chamfering process for grinding the outer peripheral part 101a to a predetermined diameter dimension, a chamfering process for forming the chamfered part 101b using the grindstone square face 106b, and the like are performed.

  After this processing is completed, the control unit 140 drives the X stage moving motor 108 a and the Y stage moving motor 109 a of the grindstone positioning stage 110 to move the grindstone 106 to the position of the camera 105.

Then, by moving the grindstone motor 107a to the origin position, the image of the grindstone 106 can always be recognized at the same position.
Then, the control unit 140 acquires an image of the grindstone 106 with the camera 105. In this case, the control unit 140 grasps a state change of the grindstone 106 in (2) image recognition processing described later.

When no abnormality is found in the grindstone 106, the controller 140 starts processing the next optical element 101.
When an abnormal shape change is observed in the grindstone 106, the controller 140 drives the X stage moving motor 108 a and the Y stage moving motor 109 a of the grindstone positioning stage 110 to move the grindstone 106 to the position of the correcting grindstone 104. .

  And the control part 140 rotates the grindstone 106 by driving the grindstone motor 107a. At the same time, the control unit 140 rotates the fixed-side work spindle 120 and the movable-side work spindle 130 that hold the optical element 101.

  The control unit 140 brings the grinding wheel 106 into contact with the correction grinding wheel 104 fixed and rotating on the fixed-side work spindle 120, so that the grinding wheel surface 106a, the grinding wheel angular surface 106b, the flange portion 106c, etc. Correct the grinding surface.

  Thereafter, the control unit 140 operates the X stage moving motor 108a and the Y stage moving motor 109a of the grindstone positioning stage 110 to move the grindstone 106 to the processing position of the optical element 101, and the centering processing of the next optical element 101 is performed. to go into.

  Note that the control unit 140 determines that the position of the grindstone 106 and the external shape of the grindstone 106 are still abnormal after the correction by using the correction grindstone 104 described above, and that the life of the grindstone 106 has expired (replacement time due to wear). Judgment is made, and an alarm for requesting replacement of the grindstone 106 is given to the operator.

(2) Image Recognition Processing An image recognition method for the grindstone 106 using the camera 105 in this embodiment will be illustrated in more detail with reference to FIGS.

  The control unit 140 drives the X stage moving motor 108 a and the Y stage moving motor 109 a of the grindstone positioning stage 110 to move the grindstone 106 to a position within the photographing range of the camera 105.

The control unit 140 acquires an image of the grindstone surface (the grindstone surface 106a, the grindstone angular surface 106b, and the flange 106c) of the grindstone 106 with the camera 105.
The control unit 140 detects the grindstone wear 204 within the grindstone surface recognition range 203 from the acquired image of the grindstone 106. For example, it is confirmed whether or not the unevenness that is formed by grinding is observed. If there is no damage, the process proceeds to recognition of the next image analysis location. When the grindstone 106 is damaged, the grindstone 106 is moved to the position of the correcting grindstone 104 and correction is performed.

After the correction of the grindstone 106, the control unit 140 moves the grindstone 106 again to the imaging range of the camera 105, and again detects wear of each part of the grindstone 106 from the beginning.
Next, the control unit 140 detects the grindstone wear groove 205 in the grindstone surface recognition range 203. If the groove 205 is not detected, the process proceeds to the recognition of the next image analysis location (for example, the grindstone corner recognition range 202).

  When the control unit 140 detects an abnormality in the grindstone angle part recognition range 202, the control unit 140 moves the grindstone 106 to the position of the correction grindstone 104 to correct the grindstone 106, moves to the camera 105 again, and moves the grindstone 106. The wear detection is performed again from the beginning.

  Next, the control unit 140 detects whether there is a shape displacement and a flaw in the grindstone surface recognition range 203. If there is no shape displacement and no flaw in the grinding wheel surface recognition range 203, the process proceeds to recognition of an image analysis location.

  On the other hand, if the controller 140 detects an abnormality in the grindstone surface recognition range 203, the grindstone 106 is corrected by moving the grindstone 106 to the position of the correction grindstone 104, and the grindstone is again moved to the photographing range of the camera 105. 106 is moved, and wear detection of the grindstone 106 is performed again from the beginning.

  When the grinding wheel 106 is significantly worn by repeating grinding many times, the control unit 140 detects an uncorrectable breakage in the grindstone 106 or corrects the grindstone 106 several times. In such a case, the operator is notified of an exchange request for a new grindstone 106.

  Next, the control unit 140 recognizes the difference between the reference position when the grindstone 102 is recognized and the position recognized by the grindstone 201 after grinding as the wear of the grindstone 106, and the wear difference 207 of the grindstone surface 106a. Then, the wear difference 206 between the grindstone square face 106b and the flange 106c is calculated.

  From this result, when the values such as the wear difference 206 and the wear difference 207 exceed a certain reference value, the control unit 140 recognizes that it is time to replace the grindstone 106 and notifies the operator of a request to replace the grindstone 106.

  When the control unit 140 determines that the wear of the grindstone 106 (wear difference 206, wear difference 207) is within a normal range, the calculated wear difference 207 of the grindstone surface 106a and the wear difference 206 of the grindstone square surface 106b and the flange 106c are calculated. Is added to the cutting amount of the grindstone 106 during grinding of the optical element 101 to correct it.

  The control unit 140 moves the grindstone 106 to the processing position of the optical element 101, and performs grinding of the outer peripheral portion 101a and the chamfered portion 101b in a state where the cutting amount is corrected by the wear difference 206.

  After the grinding is completed, the control unit 140 replaces the processed optical element 101 sandwiched between the fixed holder 102 and the movable side holder 103 with the optical element 101 as a new workpiece, and again sets the grindstone 106 to the imaging range of the camera 105. And the wear detection of the grindstone 106 is performed again from the beginning.

(3) Method for recognizing the state of the grindstone An example of a method for recognizing the state of the grindstone 106 by analyzing the image of the grindstone 106 in the control unit 140 of the present embodiment will be described.

  The controller 140 first registers the shape of the new grindstone 106 before grinding in all recognition of the grindstone angle recognition range 202 including the grindstone angle face 106b and the flange 106c of the grindstone 106. The image of the new grindstone 106 and the image of the grindstone 106 after grinding are compared to determine a change in the state of the grindstone 106.

First, the control unit 140 performs pattern recognition in order to find the corner portion of the grindstone 106 from the image. The controller 140 finds the approximate position of the grindstone 106 by this pattern recognition.
Next, the control unit 140 calculates the contour of the corner portion from the grindstone 106 and the density of the background. When the contour is uneven, the control unit 140 determines that a scratch has occurred in the grindstone 106 due to grinding.

  As the next recognition process, the control unit 140 calculates the angle between the grinding wheel corner portion (grinding wheel surface 106b) and the grinding wheel surface 106a. When this angle becomes an acute angle or an obtuse angle and falls outside the range specified in advance, the control unit 140 determines that the grindstone 106 is worn. The control unit 140 calculates the angle and position information obtained at this time and reflects them in the grinding correction value of the corner portion.

In the recognition of the grindstone surface recognition range 203, the control unit 140 needs to detect two types of recognition of the grindstone wear 204 and the grindstone wear groove 205.
In the detection of the grindstone wear 204, the control unit 140 recognizes the grindstone surface 106a and finds an approximate position on the image. Furthermore, the control part 140 detects the grindstone surface 106a from the difference in the shading of the grindstone 106 and the background.

The control unit 140 calculates the total area of the grindstone portion from the grindstone surface 106a detected as described above, and detects wear compared with the area of the grindstone 106 that is initially registered and is not used.
Next, the control unit 140 calculates the difference between the maximum concave portion and the minimum convex portion of the grindstone surface 106a, and determines that there is wear if the difference is equal to or greater than a specified value.

  Next, the control unit 140 finds several points on the grindstone surface 106a on the grindstone surface 106a and calculates the inclination. If the difference between the inclination of the unused grindstone 106 that is initially registered is equal to or greater than a specified value, it is determined that the wear has occurred.

  The controller 140 recognizes the grindstone wear groove 205 as follows. That is, when there is a flaw such as the groove 205 on the grindstone surface 106a, the flaw appears as a vertical line in the circumferential direction (vertical direction in FIG. 3) due to light refraction in the image of the grindstone 106. The control unit 140 determines that this vertical line is a scratch generated by grinding.

Next, based on the above description of (1) to (3), the operation of the processing apparatus M1 of the present embodiment will be described with reference to the flowchart of FIG.
When detecting that the unused grindstone 106 is mounted on the processing apparatus M1, the control unit 140 recognizes the shape of the grindstone 106 using the camera 105 (step 301), and uses the recognition result as the initial position of the grindstone 106. Stored as (initial shape) information (step 302).

  At this time, the control unit 140 determines whether or not there is an abnormality such as the shape of the grindstone 106 recognized in step 301 (step 303), and if an abnormality such as a defect is detected, the operator has failed in the production of the optical element 101. A warning is given of the possibility of occurrence (step 304).

  Thereafter, the control unit 140 controls the fixed-side work spindle 120 and the movable-side work spindle 130, holds the optical element 101 between the fixed holder 102 and the movable-side holder 103, and executes bell clamp type centering. (Step 305).

  Thereafter, the control unit 140 controls the grindstone positioning stage 110, brings the rotating grindstone 106 into contact with the rotating optical element 101, and grinds the outer peripheral portion 101a to a predetermined diameter dimension into a perfect circle, Chamfering for forming the chamfered portion 101b is performed (steps 306 and 307).

  When the processing of the optical element 101 is completed (step 307), the control unit 140 moves the grindstone 106 to the imaging range of the camera 105 and recognizes the external shape of the grindstone 106 (step 308).

  And the control part 140 discriminate | determines the presence or absence of abnormality in the shape of the grindstone 106 by comparison with the initial position information registered at the above-mentioned step 302 (step 309). Returning to 305, another unprocessed optical element 101 is held between the fixed holder 102 and the movable side holder 103, and processing in and after step 306 is started. At this time, the control unit 140 corrects the cutting amount of the grindstone 106 with respect to the optical element 101 by the wear difference 206 of the grindstone 106.

  On the other hand, when an abnormality is detected in the processed grindstone 106 in step 309, the control unit 140 moves the grindstone 106 to the position of the correction grindstone 104 and performs necessary correction (step 310).

Furthermore, the control unit 140 recognizes the external shape of the corrected grindstone 106 (step 311).
Then, if there is no abnormality in the grindstone 106 (that is, the abnormality is eliminated by the correction using the correction grindstone 104) (step 312), the control unit 140 returns to the above-described step 305 and continues the processing. To do.

If it is determined in step 312 that the abnormality of the grindstone 106 has not been eliminated by the correction of the grindstone 106 by the correction grindstone 104, the control unit 140 notifies the operator of a replacement request for the grindstone 106. Output (step 313).
(effect)
According to the processing apparatus M1 of the present embodiment, since the camera 105 and the control unit 140 that recognize the state of the grindstone 106 by image processing and the correction grindstone 104 are provided, the grindstone used for grinding the optical element 101 By acquiring an image directly from the surface of the camera 106 with the camera 105 and analyzing the obtained image of the grindstone 106, the control unit 140 can grasp the deformation state of the grindstone 106.

  When the grindstone surface 106a of the grindstone 106 is deformed due to wear, the grinding portion of the grindstone 106 is corrected with the correction grindstone 104 before the workpiece such as the optical element 101 is ground. It is possible to return to a state of a grindstone.

  By providing such a mechanism, in the case of the machining apparatus M1 of the present embodiment, it is possible to automate the maintenance of the grindstone 106 to realize machining failure prevention and significant labor saving.

  Further, the controller 140 recognizes the shape change of the grindstone 106 and simultaneously recognizes the position of the grindstone 106 so as to grasp the wear state of the grindstone 106 and grind the work such as the optical element 101 based on the wear amount of the grindstone 106. By automatically correcting the cutting depth of processing, it is possible to achieve high precision in grinding processing of a workpiece such as the optical element 101 by the grindstone 106.

  Further, the control unit 140 grasps the state of wear of the grindstone 106 so that the processing device M1 automatically determines an appropriate replacement time of the grindstone 106, and prompts the operator to replace the grindstone 106. Appropriate life management becomes possible.

FIG. 5 is a plan view showing a configuration example of a processing apparatus according to another embodiment of the present invention.
In the case of the processing apparatus M2 illustrated in FIG. 5, a laser probe 150 (recognition means) is provided instead of the camera 105, and the shape of the grindstone 106 is recognized by the laser probe 150. Unlike other configurations, the other configurations are the same.

  That is, the laser probe 150 provided in the processing apparatus M2 uses, for example, a laser beam 151 made of a visible semiconductor laser, and measures the time until the laser beam 151 is reflected by the surface of the grindstone 106 and returns. Thus, the displacement of the grindstone 106 and the distance to the surface of the grindstone 106 are measured, and the control unit 140 recognizes the wear of the grindstone 106 based on the measurement result, and has the same effect as in the case of the processing apparatus M1 described above. It is possible to obtain.

  In this case, since the grindstone 106 is mounted on the grindstone positioning stage 110 via the grindstone spindle 107, the relationship between the coordinate system in the control of the grindstone positioning stage 110 and the coordinate system of the laser probe 150 is set in advance. Thus, the control unit 140 can directly and accurately measure the dimensions of each part of the grindstone 106.

  In this case, since the grindstone 106 is supported by the grindstone spindle 107 and rotates, it is not always necessary to set the irradiation direction (optical axis) of the laser beam 151 in the direction in which the optical element 101 is ground (in this case, the Y direction). Absent.

  Since the grindstone 106 is supported by the grindstone spindle 107 and rotates, if one point on the grindstone surface 106a or the grindstone angular surface 106b of the grindstone 106 can be recognized, the relationship between the grindstone 106 and the camera 105 in FIG. The laser probe 150 may be installed at a position opposite to the position where the optical element 101 is ground.

  Further, the overall dimension of the grindstone 106 may be recognized by combining the scanning movement in the X direction or the Y direction of the grindstone positioning stage 110 on which the grindstone 106 is mounted and the irradiation of the laser beam 151.

  Since the grindstone 106 is a rotary grindstone, the entire outer peripheral portion is worn almost uniformly. Therefore, the control unit 140 can determine by measuring the entire wear state in the circumferential direction of the grindstone 106 by recognizing only the displacement of a certain portion on the outer circumference of the grindstone 106 with the laser beam 151.

  Alternatively, the dimensional distribution of the entire area of the grindstone 106 in the circumferential direction may be measured by irradiating and measuring the laser beam 151 while rotating the grindstone 106. In this case, a local defect on the outer periphery of the grindstone 106 can be immediately recognized.

  In the measurement of the laser beam 151, the dimensions of each part of the grindstone 106 (for example, the diameter of the grindstone surface 106a and the flange 106c, the angle of the grindstone angular face 106b), etc. can be directly measured. Compared to the image processing used, there are advantages that simplification of the algorithm, reduction of processing load, and speeding up of processing in the shape recognition of the grindstone 106 in the control unit 140 can be realized.

In other words, the machining apparatus M2 has an advantage that the same performance as the machining apparatus M1 can be realized even if the control unit 140 is configured by a relatively inexpensive and small-scale computer.
As described above, according to the above-described embodiments of the present invention, the processing device M1 and the processing device M2 automatically correct the wear of the grindstone 106, thereby reducing the skill of maintenance work and processing defects. It is possible to prevent this and stabilize the product accuracy.

That is, in the processing apparatus using the grindstone 106, it is possible to prevent the occurrence of product defects of the optical element 101 due to the shape change of the grindstone 106 over time.
Needless to say, the present invention is not limited to the configuration exemplified in the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[Appendix 1]
This is a processing device that grinds optical elements and grinds optical elements using a grindstone. It is a technology that automatically corrects the grindstone to achieve stable quality and improved maintainability. And a rotatable clamp, a grindstone for rotating a grindstone, a grinding wheel for optical element grinding having a stage whose position can be freely moved, a measuring instrument for obtaining the shape of the grindstone, and a grindstone shape. An optical element processing apparatus comprising: an arithmetic circuit that automatically grasps and at least compares the shape acquired last time with a calculation circuit that determines the presence or absence of a shape change.

[Appendix 2]
The processing apparatus according to appendix 1, wherein a state of a corner portion formed on the grindstone is automatically recognized.

[Appendix 3]
The processing apparatus according to appendix 1, wherein, based on the recognition result according to appendix 2, the worn grinding wheel surface of the optical element grinding is automatically polished and corrected.

[Appendix 4]
The processing apparatus according to appendix 1, wherein the worn grindstone angle is automatically polished and corrected from the recognition result according to appendix 3.

[Appendix 5]
A processing apparatus for correcting a grinding wheel wear amount to a cutting depth of processing in the function of recognizing the shape of the grinding wheel described in Supplementary Notes 2 and 3.

[Appendix 6]
A processing apparatus characterized in that, in the function of recognizing a grindstone shape according to appendix 2 and appendix 3, a grindstone wear state is grasped and a replacement time is warned.

DESCRIPTION OF SYMBOLS 101 Optical element 101a Peripheral part 101b Chamfering part 102 Fixed holder 102a Edge part 103 Movable holder 103a Edge part 104 Correction grindstone 105 Camera 106 Grinding wheel 106a Grinding wheel surface 106b Grinding wheel angular surface 106c Ridge part 107 Grinding wheel spindle 107a Grinding wheel motor 107b Belt 107c Pulley 107d bearing 108 X moving table 108a X stage moving motor 109 Y moving table 109a Y stage moving motor 110 grinding wheel positioning stage 120 fixed work spindle 121 bearing 130 movable work spindle 131 bearing 140 control unit 141 control program 150 laser probe 151 laser beam 200 Unused grinding wheel 201 Grinding wheel 202 after grinding Grinding wheel corner portion recognition range 203 Grinding wheel surface recognition range 204 Grinding wheel wear 205 Groove 20 6 Wear difference 207 Wear difference M1 Processing device M2 Processing device

Claims (4)

Clamping means for holding and rotating the workpiece;
A first grindstone that abuts on the workpiece and performs grinding or polishing;
A stage for moving the mounted first whetstone;
A second grindstone that is arranged in a movable range of the first grindstone by the stage and is used to correct the first grindstone;
Recognition means for recognizing the shape of the first grindstone;
Control means for correcting the first grindstone using the second grindstone based on the shape of the first grindstone;
A processing device with The processing apparatus according to claim 1,
The control means recognizes a wear amount by comparing the shape of the first grindstone between the past and present obtained by the recognition means, and determines whether or not the first grindstone needs to be corrected using the second grindstone. The processing apparatus characterized by performing. The processing apparatus according to claim 1,
The said control means warns the replacement time of the said 1st grindstone according to the change of the said shape of the said 1st grindstone. The processing apparatus according to claim 1,
The control means controls an operation of the first grindstone and corrects a relative cutting amount of the first grindstone with respect to the workpiece so as to compensate for a change in the shape of the first grindstone. Processing equipment.

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