JPS60238265A - Chamfering grinding stone and lens grinder having thereof - Google Patents

Abstract

PURPOSE:To make it possible to carry out a chamfering process with the use of an unprocessed lens grinder in which the distance between the lens rotating axis and the grind stone rotating axis is changed in accordance with dynamic diameter information, by providing an inclined chamfering grind stone in a grind stone means. CONSTITUTION:A grind stone 3 is composed of a rough stone 3a, a bevel fabrication grind stone 3b, a flat precise fabrication grind stone 3c and a chamfering grind stone 3d. This chamfering stone 3d is in an inversed V-like shape, having a first inclined surface part 3d1 for the front side edge boundary line of a lens, a second inclined surface part 3d2 for chamfering the rear side edge boundary line of the lens, and a horizontal part 3d3 for chamfering the apex point of a bevel part. With this arrangement in which the grind stone means is provided with the chamfering grind stone, no special purpose chamfering lens grinder is required, and therefor, the chamfering of a lens may be continuously and automatically carried out with the use of a processed lens grinder.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a grinding machine for grinding an unprocessed eyeglass lens to match the shape of an eyeglass frame into which it is to be incorporated, and particularly relates to a chamfering machine. The present invention relates to a grindstone for processing and a grinding machine equipped with the same.

(Prior art) When unprocessed eyeglass lenses are ground using a beading machine and put into eyeglass frames, grinding is done to improve the contact between the groove bottom of the lens frame and the tip of the lens bevel, and to prevent bending stress from being applied to the eyeglass frame. In order to prevent the lens from cracking or breaking, it is necessary to chamfer the bevel boundary line and bevel apex of the ground lens.

Conventionally, this chamfering work has been done manually using a handrail grindstone with fine grain size. Therefore, the accuracy of chamfering often depends on the experience and feeling of the lens processing engineer, and there is a problem in that there are large individual differences. Furthermore, although the grinding process of unfinished lenses into the shape of a lens frame is increasingly automated, the chamfering process is still not automated.

However, as an automatic chamfering device, JP-A-52-122992
In the publication, a grindstone having a ■-shaped groove and a lens support means that can swing horizontally and vertically with respect to the shaft of the grindstone are provided, a ground lens is rotatably attached to this lens support means, and a grindstone having a ■ shape is provided. An automatic chamfering device that chamfers with a groove grindstone has been proposed.

However, this device is expensive because it is a dedicated device for chamfering, and it is said that the work efficiency is extremely low because lenses that have been ground using a conventional polishing machine must be replaced with a chamfering device for chamfering. There were drawbacks. In addition, since this automatic chamfering device uses a ■-shaped groove grindstone, it is necessary to chamfer the fractured chamfered lens along its bevel curve, so it is necessary to use a lens support device to swing the lens vertically and horizontally. However, the structure of the lens support device is complicated and the cost is high.

(Objective of the Invention) The present invention aims to eliminate the drawbacks of such conventional devices, and its first purpose is to provide a new grindstone useful for chamfering.

A second object of the present invention is to provide a chamfering grindstone for use with a numerically controlled beading machine.

A third object of the present invention is a beading machine that digitally measures the shape of a lens frame or a template formed in imitation thereof, and numerically controls an unprocessed lens using the measured value, and has a grindstone for chamfering. Our goal is to provide a beading machine.

(Structure of the Invention) A structural feature of the chamfering grindstone of the present invention for achieving the above object is that the chamfering grindstone has at least one inclined chamfering grinding surface on the circumference.

The structural features of the abrasive machine of the present invention to achieve the above object are as follows: Digitally measures the shape of the lens frame groove of the eyeglass frame or a template that has been processed in advance to imitate the lens frame shape; Frame or template radial information (ρ1, θ,
, )(n-1, 2, 3...N), a lens frame shape measuring means that rotates at a high speed at a predetermined position, and a lens grinding wheel that rotates at a predetermined position at a high speed. The carriage is held rotatably in correspondence with the meridian angle θゎ of the radial vector information (ρ., θ□), and the distance between the lens rotation axis and the grindstone rotation axis is determined based on the radial vector information. Radial value p. In the grinding machine for grinding a lens to be processed using the grindstone, the grindstone means has a chamfering grindstone having at least one inclined chamfering grinding surface on the circumference.

(Description of Embodiments) Outline of Apparatus A specific embodiment of the present invention will be described below with reference to the drawings. First, we will explain the configuration of the numerically controlled beading machine according to the present invention, and then we will explain the structure of the chamfering grindstone, and then explain the operation of the entire beading machine, including the final chamfering operation, using a flow chart. do.

FIG. 1 is a perspective view showing a grinding section of a chamfering machine having a chamfering device according to the present invention. A circular whetstone 3 consisting of a rough whetstone 3a, a beveled whetstone 3b, and a flat precision machining whetstone 3c is assembled in the whetstone chamber 2 of the housing 1, and this whetstone 3 is attached to a pulley 4.
It is attached to a rotating shaft 5 having a. The pulley 4 is connected to a rotating shaft of a grindstone motor 6 via a belt 7, and as the grindstone motor 6 rotates, the grindstone 3 is rotated.

A carriage shaft 12 is supported rotatably and slidably in the axial direction by a bearing 10.11 formed in the housing 1, and one end of the carriage shaft 12 is supported by a bearing 21a formed in a feed base 20, which will be described later. It is rotatably inserted into the Arms 14, 15 of the carriage 13 are fixed to this carriage shaft.

Further, a lens rotation shaft 18 for chucking and rotating the lens LE to be processed is attached to the arms 16 and 17.

A chuck handle 19 is attached to one shaft 18a of the lens rotation shaft 18, and by rotating the chuck handle 19, the shaft 18a slides in the axial direction to chuck the lens to be processed.

Further, an arm portion 31 of a lens measurement device 30 (described later) is attached to the carriage shaft 12 so as to be able to swing coaxially with the swing axis of the carriage 13.
is installed.

Wheels 22 are attached to the base plate 21 of the feed platform 20, and the wheels 22 are removably placed on rails 23 attached to the housing 1, so that the feed platform can be moved along the rails 23. It is held in The female threaded portion 24 of the feed base 20 meshes with a feed screw 41 that rotates coaxially with the rotation axis of the motor 40, and the rotation of the motor 40 causes the feed base 20 to rotate.
is moved left and right as shown by arrow 25. As described above, a bearing 21a is formed on this feed base 20,
Since the carriage shaft 12 is attached to this bearing 21a, the carriage 13 also moves laterally when the feed table 20 moves laterally. Furthermore, two parallel shafts 26 and 26' are implanted in the base plate 21 of the feed table 20, and a stopper member 27 is attached to these shafts so as to be movable up and down. A female screw portion 28 is formed in the abutting member 27, and the abutting feed motor 42 is connected to this female threaded portion 28.
A feed screw 43 fixed coaxially with the rotating shaft of the motor 42 is engaged with the rotating shaft, and the abutting member 27 is moved up and down by the rotation of the motor 42.

A rotating ring 16b attached to the tip of an arm 16a protruding from the carriage 13 is in contact with the upper surface of the abutting member 27, and as the abutting member 27 moves up and down, the carriage 1
3 is configured to be swung.

Lens Frame Measuring Means FIG. 2 is a perspective view showing an example of a measuring means for digitally measuring the shape of a lens frame of eyeglasses or a lower mold molded in advance in imitation thereof. An overhanging shaft 18b of the lens rotation shaft 18 that overhangs the arm 16 of the carriage 13
is fitted into a bearing 50 formed on the carriage 13. One long side frame 52 of a detection arm 51 made of a rectangular rod-shaped frame is attached to the end 18c of the shaft 18b in a direction perpendicular to the rotation axis of the shaft 18b. A detector 54 is slidably attached to the other long side frame 53, and this detector is always pressed toward the end of the frame by a spring 59 inserted into the frame 53. A pulley 57 is attached to the short side frame 55, 56 of the detection arm 51.
．． 58 is rotatably attached. - A pulley 60 is rotatably inserted into the blade shaft 18b, and a code plate 62 of an encoder 61 is fixed coaxially to this pulley 60. The detection head 62a of the encoder is fixed to the outer surface of the arm 16 of the carriage 13. One end of the first wire 80 is fixed to the detector 54, and after being wound around the Boo IJ-60 via the pulley 57, the other end is fixed to the Boo'J-60.
-60 is fixed to the side. Also, the second wire 8
1 is fixed to the detector 54 at one end, wound around the pulley 60 via the pulley 58 in the opposite direction to the first wire, and then fixed at the other end to the side surface of the pulley 60. As a result, the amount of sliding movement of the detector 54 on the frames 5 and 3 is read as the amount of rotation of the pulley 60, that is, the code plate of the encoder 61.

As shown in FIG. 3, the detector 54 includes a sliding seat 541 that is slidably fitted into the frame 53, and an axis O8 attached to the sliding seat.
The detection feeler part 542 is rotatable around the axis 0 and is slidably attached in the axial direction of the axis 0. The feeler part 542 includes a template detection contact 544 having a semicircular cross section and cut out in the rotating sliding shaft 543;
The lens frame detection peripheral contact wheel 546 is rotatably attached to the end of a substantially U-shaped arm member 545 attached to a rotational sliding shaft 543. A contact surface 544a of the contactor 544 and a contact peripheral surface 546a of the contact wheel 546 are both configured to be located on the axis O. A pin 547 is penetrated and fixed in parallel to the contact surface 544a near the other end of the rotating and sliding shaft, and this pin is attached to a locking member 548 attached to the long side frame 52 when the detector is in the initial position. The sides are in contact.

Inside the carriage 13 is a lens shaft rotation motor 70 and a sprocket wheel 7 that is rotated by the rotation of this monitor 70.
It has a built-in sprocket axle 71 with 2.73 at both ends. Further, sprocket wheels 74 and 75 are provided on each of the lens rotation shafts 18 and 18a, a tune 76 is provided on the sprocket wheels 72 and 74, and a tune 76 is provided on the sprocket wheels 72 and 74, and a tune 76 is provided on the sprocket wheels 72 and 74,
3.75 is provided with a tune 77, which is configured to transmit the rotation of the motor 70 through the rotation of the lens rotation axis.

On the other hand, when the pedestal 91 of the eyeglass frame holding means 90 is located in the initial fixed position of the carriage 13, the arm 16 of the jewelery machine housing 1 is
installed parallel to the longitudinal direction of the This pedestal 9
1 has two wooden rails 92 and 93 attached parallel to the longitudinal direction of the arm 16 of the carriage 13.
．． Spectacle frame holder support members 94 and 95 are slidably disposed at 93 . Support members 94 and 95 are constantly tensioned by springs 96. A feed screw 97a provided on a rotating shaft of a motor 97 is engaged with a leg portion 95a of the support member 95. The upper parts of the arms 94b and 95b of the support members 94 and 95 have clamping tools 94c and 95c for clamping the spectacle frame holder 100 in which the spectacle frame 200 is set.

When supporting the template with the above-mentioned eyeglass frame holder support members 94 and 95, a template holder 110 is used as shown in FIG. The template holder 110 includes a support frame 111, cylindrical members 112 and 113 attached to both ends of the support frame 111, and a template mounting column 114 installed in the center of the support frame 111.
and a pin 114.11 planted on the end face of this mounting support.
5.116. The template 210 allows the pins 114, 115 to be inserted by holes pre-formed therein.
．． 116 to be attached to the mounting column, and supported by holding this template holder between supporting members 94 and 95.

Operation of Measuring Means Next, the measurement of an eyeglass lens frame by the measuring means having the above-mentioned configuration will be explained below.

The eyeglass frame holder 100 is held between the support members 94 and 95, and the motor 40 moves the carriage 13 in the direction of the arrow Δ (see FIG. 1).
After moving the holder 100 by a predetermined amount in the direction of the rail 92., the motor 97 is rotated so that the lower groove 201 of the lens frame 200 at the initial set position and the contact wheel 546 contact on the same plane. 93 by a predetermined amount so that the rotation center 02 of the detection arm 51 is located at the center of the lens frame. At this time, the lower groove 201 of the lens frame 200 hooks the contact wheel 546, and at the same time the pin 547 is released from the locking member 548, allowing the rotating and sliding shaft 543 to rotate freely. The amount of movement of the detector 54 on the frame 53 is converted into the amount of rotation of the encoder by wires 80 and 81.

Now, when the carriage 13 and the detection arm 51 are in the initial fixed position as shown in FIG. 2, the detector 54 is not in contact with the eyeglass frame but is in the initial position as shown in FIG. The origin 0 is set on the line of the axis o1, and the distance from this origin 0 to the rotation center 0□ of the detection arm 51 is l.
Let the count value of the encoder due to the movement of the detector due to the fixed amount of movement of the eyeglass frame and rotation of the detection arm be C, , and the resolution of the encoder be e °/pul.
se.

At this time, the resolution calculated by converting the amount of movement of the detector is d (m
m) /pulse so that the detection arm 51 is parallel to the arm 16 of the carriage 13 at the above-mentioned initial position, and if this is set as a reference angle of 0°, the movement of the lens frame at the rotation angle θ□ of the detection arm 51 is Diameter ρ.

In this embodiment, when the encoder 61 detects the amount of movement of the detector 54 on the detection arm 5'1, the amount of rotation of the detection arm is also detected, so θ.

pn = It - (Ch-) d - 41) e.

given as. Note that from equation (1), θn-0, that is, the vector radius ρ at the reference position. is ρ. = Il −Cod (2).

In this way, if the detection arm 51 is rotated around the entire circumference of the lens frame, the lens frame 200 at the rotation center of 0°
Shape information (ρ1, θ.) (where n=Q, ■, 2.
3...N) are obtained as digital values.

- Template Measuring Means FIG. 21 is a schematic diagram showing a method of measuring the shape of a template when a template is used instead of a lens frame.

Components that are the same as those in FIG. 5 described above are given the same reference numerals, and the following explanation will be omitted. In the case of template measurement, the shape of the template is measured by bringing the template detection contact 544 into contact with the peripheral surface 211 of the template 210 and rotating the detection arm 51. In order to place the rotation center 02 of the detection arm 51 within the template, it is moved a predetermined distance from a predetermined origin 0.

Also, the dynamic radius tρ before the detection arm is located at the angular position θ. is given as, and the reference angle θ. The dynamic radius tρ at
. is Lρ. −Cod −12 (7).

Template shape information (tph, θ, ,) (n
-0, 1, 2, 3...N), find the geometric center of the template, move the rotation center of the detection arm to that position, measure again, and store the data. This is the same as in the lens frame measurement described above.

In this embodiment, as shown in FIG. 3, the contact point 546a of the contact shaft 546 inscribed in the groove of the lens frame and the contact surface 544a of the ball amount contact 544 are both aligned with the rotating sliding shaft 543. configured to be located on the rotation axis O1,
During measurement, the rotating and sliding shaft is rotated so that the contact shaft 546 or the contactor 544 receives contact pressure and the arm member 545 is positioned in the normal direction of the contact surface at the contact point, thereby ensuring accurate measurement at all times.

Grinding Mechanism Next, the structure and operation for grinding an unshaped lens based on the measurement values of the lens frame or template obtained in this way will be explained with reference to FIG. Lens rotation axis 18.18a (
(see FIG. 1), the unshaped lens is chucked, and the grindstone rotating motor 6 is driven to rotate the grindstone 3, and the unshaped lens is pressed against the grindstone 3 by the weight of the carriage and processed.

In the present invention, the unshaped lens LE has the shape measurement value (ρ., θ,) (n=0.1.2.3・) of the lens frame or template described above.
...N) is processed according to the numerical data given. Carriage swing amount! , , a linear encoder 610 is used in this embodiment. This encoder consists of a scale 611 whose one end is rotatably attached to the side of the arm 31 of the lens measuring device 30 around a fulcrum P, and a detection head 612 which is also rotatably attached to the side of the carriage 13. It is configured. The rotation angle T of the carriage given by the carriage swing amount lh is also the same as the rotation angle T of the detection head 612. Movement of the detection head as the carriage rotates is detected as a read value on the scale. In this embodiment, since the scale 611 is rotatable about the fulcrum P, the distance between the reading values e1-02 of the detection head actually gives a distance C of e,'-e2. On the other hand, a circular arc 61 whose radius is the distance R5 between the rotation axis 12 of the carriage and the fulcrum P
The length P of the string stretched at the carriage rotation angle T in 3 is designed to be the same length as the aforementioned distance C. Therefore, the amount read by the encoder 610 is directly the length of the string stretched at the carriage rotation angle T. The structure is configured such that the amount of swing is 1, and twice that amount is 1. In this way, the progress of machining is checked from time to time by the encoder 610, and the vector radius ρ is adjusted. When processing
The acid threaded portion 28 of the stopper member 27 contacts the rotating wheel 166, stopping further processing, and then the lens shaft rotation motor 70 is rotated by a predetermined unit angle, which is the same amount as when measuring the lens frame. The lens LE is rotated to the position θ,' and its radius vector value ρ. Process lenses L and E until ' is obtained. This is the lens frame measurement data (ρ0, θ, ,) (n=o
, ■, 2.3-...N), the lens processing is repeatedly performed on the lens frame measurement values.

Lens Measuring Means Next, the configuration of the lens measuring device 30 shown in FIG. 1 will be explained based on FIGS. 9 and 10. Shafts 302 and 303 are implanted in the base 301 that extends vertically from the arm portion 31, one end of a link arm 304 is rotatably attached to the shaft 302, and a link arm 305 is attached to the shaft 303.
One end is rotatably attached. link arm 3
The other ends of 04.305 are shafts 307.30 provided on arm portions 309.310 at both ends of link par 306, respectively.
8, and these link arms 304, 305 and link pars 306 constitute a parallel link mechanism. Each of the arm parts 309.310 has an axis 311.31 parallel to the running direction of the link par 306.
One end of each of the two is implanted through a modified oval frame 317 and 318. The other ends of the shafts 311, 312 are rotatably fitted into modified oval-shaped frames 313, 314. A U-shaped arm 315a is provided at the middle of the shaft 311.
A shaft member 315 having a diameter of
It is rotatably inserted in a. The piece 316 has a pin 319 implanted in its upper part, and a sleeve 320a of an arm member 320 is slidably inserted into the working part of the pin 319.

The other end of this arm member 320 is rotatably supported by a shaft 321 implanted in the base 301.

Similarly, a shaft member 322 having a U-shaped arm portion 322a is inserted into the middle portion of the shaft 312 so as to be slidable on the shaft.
This shaft member 322 is further rotatably inserted into a bearing portion 323a of a piece 323.

The piece 323 has a sleeve (325a) formed at one end of the arm member 325 at the useful part of the pin 324 implanted in the upper part of the piece 323.
is slidably inserted. The other end of this arm member 325 is rotatably supported by a shaft 326 implanted in the base 301.

On each side of the arm members 320 and 325, wheels 3 are rotatably attached to both ends of an arm piece 331 attached to the rotating shaft of a motor 330 attached to the base 301.
32.333 are in contact. A detection head 335 of an encoder 334 is attached to the shaft 33 in the middle part of the arm member 320.
The encoder scale 337 is inserted into the detection head 335 so as to be rotatable about the detection head 335 . One end of the scale 337 is rotatably held by the base 301. Similarly, a detection head 339 of an encoder 338 is suspended from an intermediate portion of the arm member 325, and a scale 340 is inserted therethrough.

Attached to the frames 317 and 318 are the opposite ends of two rail members 341 and 342 that pass through the frames 313 and 314 and run parallel to the link pars 306 for holding them. Both ends of a cylindrical member 345 are fitted into the frames 313 and 314 held by these rail members 341 and 342, and the cylindrical member 345 is coaxially disposed within the cylindrical member.
3 is slidably inserted. A groove 343a is formed on the circumferential surface of the end of the cylindrical member 343.
A U-shaped arm portion 315a of the shaft member 315 is rotatably inserted into the shaft member 315a. Similarly, the frame 314 has a cylindrical member 3
The other end of 45 is fitted, and a cylindrical member 346 is rotatably fitted coaxially within this cylindrical member 345. A groove 346a is also formed on the circumferential surface of the end of the cylindrical member 346, and the U-shaped arm portion 32 of the shaft member 322 is inserted into this groove 346a.
2a is rotatably inserted.

A ring 3 having a slope 347a is provided on the outside of the cylindrical member 345.
47 and a ring 348 having a slope 348a are slidably fitted. A slot groove 345a is formed in the circumferential surface of the cylindrical member 345 in parallel to the axial direction, and pins 349 and 350 are passed through the slot groove, and the pin 349 is coupled to the ring 347 and the cylindrical member 343. . Further, the pin 350 is coupled to the ring 348 and the cylindrical member 346. Furthermore, pins 351.
352 are respectively penetrated, and both these pins 351
．． A spring 353 is stretched between 352 and 352. This spring 3
53, the cylindrical members 343 and 346 are always subjected to force to reduce the distance between them, and the cylindrical members and the pin 349.35
Rings 347 and 348 that are connected via 0 are also subjected to forces to reduce the distance between them.

Operation of Lens Measuring Means Next, the operation of the lens measuring device having the above configuration will be explained. FIG. 11 is a schematic diagram showing a method of measuring the shape of the ground lens LE using the above-mentioned lens measuring device. The processed lens LE is returned to its home position by the return of the carriage 13. Next, the eccentric cam 360 is rotated by a drive means (not shown), the lens measuring device is tilted about the shaft 12, and the cylindrical member 3 of the lens measuring device is rotated.
45 is brought into contact with the edge surface of the processed lens LE.

Next, the lens rotation axis is rotated in a staggered manner by a predetermined unit angle similar to that used during lens processing, and the vector radius ρ' of the processed lens at that time is measured. To measure this radius vector ρ', the encoder 610 used to measure the radius vector value during processing of the unshaped lens described in FIG. 8 is used.

During processing, the radius vector was measured based on the read value of the detection head 612 that moved on the scale 611 as the carriage 13 oscillated, but when measuring the radius vector of the processing lens in FIG. The difference is that the scale that moves with the swing is read by a detection head 612 attached to a fixed carriage 13.

Next, the measurement of the lens curve value and the measurement of the lens edge pressure by the lens measuring device 30 will be explained based on FIGS. 12 to 14. Motor 33 of lens 1 measuring device
0 and rotate the arm member 320.32 of the arm piece 331.
Release the contact with 5. By this contact and release, the cylindrical members 343 and 346 shorten the distance between them due to the tension of the spring 353. The ring 34 connected to the cylindrical member by this
7.348 pinches the edge of the processed lens LE between its slopes. The movement of the cylinder members 343 and 346 at this time acts as rotation of the arm members 320 and 325, and the amount of movement of the arm members, that is, the amount of movement of the rings 347 and 348 is measured by encoders 334 and 338, respectively. and motor 7
By rotating 0, the processing lens LE is rotated, and the ring 347.348 at the radius vector for each radial line for each unit angle.
Measure the amount of movement. As shown in the schematic diagram of FIG. 14, the measured value of the ring 347 at the A position of the processed lens LE is
When the measured values at positions ZA and B are fZB -', the radius at position A is ρ'4, and the radius at position B is ρ'8,
If the center of curvature of the front surface of the lens LE, which is set on the lens rotation axis, is fZO, and the radius of curvature of the front surface is R4, then ρ'A" + (rZo tlA)2=L')...(3
) ρ'B" + (rZorZs)2=Rr" holds true. From this third equation, R7 is obtained, and from the fourth equation, the lens front curve value C4 is obtained.

Note that in equation (4), n is the refractive index of the lens, which is generally given as 1.523.

If the measured values of the ring 348 are bZA, bZn, the center of curvature of the rear surface of the lens LE is )Zo, and the radius of curvature of the rear surface is R5, then ρ'A' + ('bZo bL )2=Rb)...
・[5] From ρ'B"+(bZo bL)"=Rb, the rear surface curve value Cb of the lens can be obtained from ttb.

Also, the edge thickness △A1ΔB is fZAbZA”△A )・・・・・・・・・・・・・・・・・・・・・(6)
It is given as rlA bL =ΔB.

Chamfering Means for Grinding Lens FIG. 15 is a diagram showing a more accurate configuration of the grinding wheel 3 of FIG. 1. The rough grindstone 3a is composed of a diamond electrodeposited grindstone 3a+ for grinding plastics and a diamond metal bond grindstone 3a2 for grinding glass lenses. The bevel processing grindstone 3b is used for processing the large beveling of a lens with a small edge thickness, and the ■-shaped groove 3bl, which is used for processing a large bevel on a lens with a large edge thickness, and the groove 3bl is used for processing a small beveling of a lens with a large edge thickness. It has a gentle slope portion 3b2 that cooperates with 3b+. (2) The angle T1 of the slope of the groove 3b+ is designed to be 60° in this embodiment. On the other hand, the inclination angle T2 of the gentle slope portion is set to 80°. A flat precision machining whetstone 3c is provided on the right side of the beveling whetstone 3b, and a chamfering whetstone 3d is arranged between the flat precision whetstone 3c and the rough grinding wheel 3a described above.

The chamfering grindstone 3d has a first slope part 3d for chamfering the front edge boundary line of the lens, a second slope part 3d2 for chamfering the rear edge boundary line, and a horizontal part 3d3 for chamfering the bevel apex. It is an inverted V-shaped whetstone consisting of. In this embodiment, these grinding surfaces 3d, 3d2, and 3d3 are all diamond metal bond grindstones with the same grain size, and the grain size is 500 mesh, but the present invention is not limited to this, and the material of the lens to be machined is , the grain size of each grinding surface may be made different based on the curve value or the like.

The first slope portion 3d+ has an inclination angle η1 to prevent interference with the front refractive surface of the lens when chamfering the front edge boundary line.
In this embodiment, η1 = 55°. The present inventors determined from various experiments that the inclination angle η
1 was found to be preferably in the range of 40°-≦η1-≦T1. Note that T1 is the slope angle of the ■-shaped groove 3b+ of the beveling grindstone 3b, as described above. On the other hand, when the second slope portion 3d2 chamfers the rear edge boundary line, the spectacle lens is generally a meniscus lens. Since the rear refractive surface and the edge surface of the lens sharply intersect, and there is no interference between the rear refractive surface and the ground surface, the inclination angle η2 is preferably made steeper than η1. The inventors obtained experimental results of 20°−≦η2−≦45.
It has been found that a range of . In this example, η2
= 30'.

The grindstone 3 having the above structure is rotated by a motor 6 (see FIG. 1) at a circumferential speed of 800 to 1200 m/min.

Control Circuit Configuration FIG. 16 is a block diagram showing the electrical system for driving and controlling the beading machine having the mechanical configuration described above. The arithmetic control circuit 1500, which is composed of a microprocessor for various calculations and program control, includes a Y-axis motor 97, a lens axis rotation motor 70, and a lens measuring device rotation motor 12.
08, a motor drive device 1200 for driving the carriage feed (Z-axis) motor 40, the abutment movement (X-axis) motor 42, and the grindstone rotation motor 6, and the encoders 61, 334, 338, and 610. A counter circuit 1100 for counting detection signals and an arithmetic control circuit 150
a frame shape memo U 1300 for storing measurement information of the eyeglass frame or template from 0; an input keyboard 1401;
Liquid crystal display 1402 and interface circuit 1
403, and a bevel information memo 'J1600 are connected.

Operation Sequence of the Ball Drilling Machine The operation of the ball rolling machine having the above-mentioned configuration will be explained below based on the flowchart shown in FIG.

(1) Step 1 [Lens rod needle measurement] In response to the start command, the arithmetic control circuit operates the motor drive device 1200 according to the program in its own program memory.
The needle measuring device is driven through the lens frame 200 to measure a desired lens frame on the right or left side of the eyeglass frame 200. Motor drive device 1
200, the lens shaft rotation motor 70 is controlled by a clock pulse CP from a pulse generator in the arithmetic control circuit 1500.
to control the rotation and rotate the detection arm. The detector 54 on the detection arm traces the lens frame with which it is in contact and moves on the arm along its vector radius ρ.The encoder 61 detects the amount of movement, and the detection signal is sent to the counter circuit 11.
Count by 00. The counter circuit 1100 receives a clock pulse CP from the pulse generator of the arithmetic control circuit 1500.
is input, the vector radius ρ is counted in synchronization with this clock pulse, in other words, in correspondence with the rotation angle θ of the detection arm. Sensing arm - radial value set in rotation (ρ.,
θ. ) (n=o, 1.2,...n) in the calculation control circuit 1.
500 and is temporarily stored in the frame shape memory 1300.

(2) Step 2 [Rough grinding] After rotating the grindstone motor via the motor drive device 1200, the carriage feed motor 40 is rotated to position the lens to be processed held by the carriage 13 on the rough grindstone. Next, the lens shaft rotation motor 70 is connected to the arithmetic control circuit 15.
The lens is rotated by the clock pulse from the pulse generator 00, and the lens rotation axis is positioned at the reference position θ-0.

Next, the abutment moving motor 42 is rotated to lower the abutment 27, the lens is lowered, and rough machining is started. The machining radius of the lens is detected by the encoder 610, counted by the counter circuit 1100, and the frame shape is memorized! Radius ρ corresponding to θ−〇 of frame radius information (ρ1, θ, ,) in J1300
. The arithmetic control circuit 1500 compares the machining radius ρ'0 with ρ. When the moving motor 4 reaches a predetermined value close to
2 is reversed, the abutment stop 27 is raised, the lens is released from the grindstone, the lens axis rotation motor is then rotated by a unit angle, and the process proceeds to the meridian θ1.Then, the same steps are repeated to complete one rotation of the lens rotation axis. In other words, the lens is processed until the rotation angle θ9 of the lens rotation axis is reached, and the lens is compared with the lens frame vector radius (ph, θ,) in the frame shape memory. θ. When the machining up to this point is completed, the abutment moving motor 42 is rotated to return the carriage 42 to the reference position, and at the same time the grindstone motor is stopped.

(3) Step 3 [Lens measurement] Rotate the lens measurement device rotating moke and use the eccentric cam 360
The holding of the lens measuring device 30 is released, and the measuring device 30 is rotated by its own weight to bring the cylindrical member 345 into contact with the processed lens. Next, rotate the arm motor 330 to rotate the arm piece 3.
Release the hold on 20 and 325, and sandwich the edge of the processed lens with rings 347 and 348. Lens shaft rotation motor 70
and rotate the roughly ground lens.

The encoder 610 calculates the radius vector value ρ' for each rotation of the lens axis,
, (n=0.2...n), for example, if we take FIG. It is input to the control circuit 1500.

Further, the encoder 334 detects the rla value at the front edge position of the roughly ground lens, that is, at the rotation angle θ in FIG. 14, and causes the counter circuit 1100 to count it. This information is manually input to the arithmetic control circuit 1500. Similarly, the encoder 338 determines the position of the rear edge of the roughly ground lens, for example, the rotation angle θ.
, is detected and counted by the counter circuit 1100, and the result is input to the arithmetic control circuit. As a result, the arithmetic control circuit 1500 has each radial angle θ, (n=0,
], 2,...n) front edge position information rzh(n=
o, 1.2,”・n), rear edge position information bZo(
n=0. I, 2, ... n ) and radius vector p'h (n=
0.1.2.n) is input, and the front curve CF, rear curve Cb, and edge thickness Δ of the rough-ground lens are input according to equations (8) to (12) described above.

(n=0.1.2...n) is calculated. After the lens measurement is completed, the motor drive device 1200 is activated to drive the motor 1.
208 to return the lens measuring device to the reference position.

(4) Step 4 [Curve/bevel position input] In the case of automatic setting, the arithmetic control circuit 1500 inputs the above-mentioned front curve value cr, rear curve value Cb, and edge thickness Δ. Based on the calculation results, an ideal bevel curve and bevel position are further calculated, and based on the calculation results, the bevel cross-sectional shape of the maximum edge thickness portion and the minimum edge thickness portion is determined by the interface 140.
3 on the screen of the display device 1402. In addition, necessary data such as the bevel curve value at that time and the distance from the front edge to the top of the bevel are displayed numerically at the same time.

In the case of manual setting, the user uses the keyboard 1401 to numerically input the desired bevel curve value and the distance from the front edge of the bevel to the apex of the bevel, the so-called offset amount. The above-mentioned keyboard input values are input manually to the arithmetic and control circuit via the interface 1403, and the above-mentioned curve values C, C, and edge thickness Δ are obtained. Based on the manually entered bevel curve value and the maximum and minimum edge thickness portions of the offset amount, the bevel cross-sectional shapes of the maximum and minimum edge thickness portions are calculated and displayed on the display 1402 via the interface 1403.
Display images and numerical values.

(5) Step 5 [Bevel processing] After confirming the bevel shape obtained in the fourth step above, if the user gives OK, activate the beveling start button on the keyboard 1401, and in accordance with the command, the arithmetic control circuit 1500 The grindstone motor 6 is rotated by the motor drive device 1200. At the same time, the bevel information memory 16
00 stores the finally determined bevel curve value, offset amount, and other bevel information in relation to the radius vector value (ρ', 1, θ,).

The carriage feed motor 40 is rotated via the motor drive device 1200 to move the rough grinding lens held by the carriage onto the beveling grindstone. The motor driving device rotates the abutting stop moving motor 42 to lower the abutting stop 27, and the carriage 13 supported by the abutting stop 27 is rotated and lowered to bring the lens into contact with the beveling grindstone to start beveling.

The arithmetic control circuit 1500 outputs the bevel information memo! J160
The motor 40 that feeds the carriage plows based on the bevel position and offset amount for each radius value '(ρ/, 1θ,) stored in the memory. The desired radius vector value ρ' is determined by controlling the abutting and stopping movement motor 42 and checking the measured value of the encoder 610 from the counter circuit 1100. Process the bevel until it looks like this. This operation is executed for all radial angles θ7.

All radial angles θ. After machining to the desired radial value p'o, the carriage 13 is rotated upward by the rotation of the abutment motor 42 and returned to the home position, and the rotation of the grindstone motor 6 is stopped to stop the grindstone.

(6) Step 6 [Re-measuring lens shape] As shown in Fig. 18, measure the machining radius (ρ'o, θ.) of the lens after beveling in the same manner as in the third step above. .

In this step, edge thickness measurement and curve value calculation are not executed.

(7) Step 7 [Machining radius determination] The machining radius (ρ11, θ.) obtained in the sixth step above and the lens frame radius information (ρ., θ9)
) and when they match, move on to the next step.

If they do not match, return to the fifth step and perform bevel processing again.

(8) Step 8 [Chamfering] 1) Step 8-1 [Determination of edge boundary line] The above-mentioned 3rd step
The front curve value Cf, the rear curve value Cb determined by the step, the bevel apex position obtained from the offset amount automatically or manually set in the fifth step, and the machining radius (ρhs) measured in the sixth step. θ,,)
is known in advance based on the design. Bevel processing grindstone 3b
Using the bevel shape, the arithmetic control circuit 1500 calculates the front edge boundary line P1 and its radius rLn, as shown in FIG.
Determine the rear edge boundary line P3, its radius, L, and the distance ALF between the front edge boundary line P and the bevel apex P2.

(+) Step 8-2 Simultaneously chamfer the front edge boundary line P1 and the edge apex P2. At this time, the rotation of the motor 40 moves the lens to a position where the slope length ε of the bevel is an angle T1 and the lens is stretched between the first slope part 3d and the horizontal part 3d3 of the chamfering grindstone 3d, as shown in FIG. Move the lens a distance L from the reference position so that the edge apex P2 is located, and then move the abutment stop 27 so that the radius vector is ρ#□−α, which is obtained by subtracting the chamfering amount α from the processing radius ρ'0 of the lens. to perform chamfering. Below, each meridian θ, (η-1, 2,
3...N) for ρ'i-α(1-1.2.3.
...Move the stopper so that it becomes N). At this time, the distance is also determined by each meridian θ according to the curve of the bevel apex.
. Needless to say, it changes every time.

iii) Step 8-2 The abutment motor 42 and the motor 40 are operated once to chamfer the rear edge boundary line P3 of the lens on the second slope portion 3d2 of the grindstone.
to perform chamfering.

In this case as well, the processing radius information of the lens (ρ11o, θ, ,
), the abutting motor 42 and the motor 40 are operated so that the entire circumference of the rear edge boundary line can be chamfered uniformly.

(Effects of the Invention) As explained above, according to the present invention, chamfering can be performed continuously and automatically using a chamfering machine for grinding unprocessed lenses without requiring a dedicated chamfering machine. have advantages.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of a lens grinding device according to the present invention, FIG. 2 is an exploded perspective view showing a lens frame measuring device, and FIG. 3 is an illustration of the structure of a detector for lens frame measurement. 4 is a schematic diagram showing the lens frame measuring operation, FIG. 5 is a schematic diagram showing the lens grinding process, FIG. 6 is a perspective view of the lens measuring device, and FIG. 7 is a plan view thereof. , Fig. 8 is a cross-sectional view thereof, Fig. 9 is a sectional view of the shaft portion, Fig. 10 is an xm-xm sectional view of Fig. 7, and Fig. 11 is a schematic diagram showing the process of measuring the lens shape after grinding. Figure 12 is a perspective view of the processed lens, Figure 13 is a plan view showing the lens measurement process,
Figure 14 is a schematic diagram showing the geometrical values of the lens shape.
Fig. 5 is a partly omitted plan view showing the structure of the grinding wheel, Fig. 16 shows the arithmetic processing circuit, Fig. 17 is a flowchart of the entire process, Fig. 18 is a schematic diagram showing the measurement of the processing lens, Fig. 1
FIG. 9 is a schematic view showing the chamfering process in relation to the abutting member, FIG. 20 is a perspective view of the template measuring device, and FIG. 21 is a schematic diagram showing template measurement. 3... Grindstone, LE... Lens, 30... Lens measuring device, 51... Detection arm, 54... Detector, 1
00... Eyeglass frame holder, 200... Lens frame, 21
0... template, 3d... grindstone for chamfering. Figure 17 Figure 19

Claims (4)

[Claims] (1) A chamfering grindstone having at least one inclined chamfering grinding surface on the circumference. (2) Claim 1, characterized in that the head angle of the ground surface for chamfering is smaller than the bevel inclination angle of the lens to be processed.
Whetstone for chamfering as described in section. (3) Digitally measure the shape of the lens frame groove of the eyeglass frame or a template that has been processed in advance into a shape that corresponds to the lens frame shape, and obtain information on the radius vector of the lens frame or template (
A lens frame shape measuring means for determining ρ0, θh ) (n=1.2.3...N), a grindstone means for lens grinding that rotates at a high speed at a predetermined position, and a lens rotation axis for fixing the eyeglass lens to be processed. a carriage held rotatably in correspondence with the meridian angle θ9' of the radius vector information (ρ7, θ,);
The distance between the lens rotation axis and the grindstone rotation axis is the radius vector value ρ of the radius vector information. In a grinding machine that grinds a lens to be processed using the grindstone, the grindstone means has a chamfering grindstone having at least one inclined chamfering grinding surface on the circumference. The characteristic Tamazuri machine. (4) Claim 3, characterized in that the inclination angle of the chamfering grindstone surface is smaller than the bevel inclination angle of the lens to be processed.
Tamazuri machine described in section.