JP3233026B2 - Cutting method of glass by lateral pressure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cutting glass, and more particularly, to cutting a glass material, for example, a rod-shaped long glass used for molding an optical element such as a lens by pressing, to obtain a high quality cut surface. The present invention relates to a method for cutting glass by lateral pressure in a field requiring a glass cutting process suitable for mass production.

[0002]

2. Description of the Related Art Conventionally, an aspherical glass lens mass-production technique by a molding method suitable for mass production of an aspherical glass lens has been established and has been achieved to date. Most of optical element materials used for molding glass lenses have a polished, ball, or polished cylindrical shape.

Recently, based on the view that an optical glass element material is one of brittle materials, a glass rod or the like is cut by lateral pressure without using a conventional tool such as a diamond cutter. A so-called side pressure cutting method as disclosed in JP-A-266323 is known. The side pressure cutting method does not involve generation of chips or noise at the time of cutting, and does not require unnecessary time and energy at all. Furthermore, the disking method disclosed in Japanese Patent Application Laid-Open No. 6-198600, in which a glass bar or the like is cut at a plurality of cross sections at the same time, a large amount of optical element material is cut by a plurality of cuts with a single increase in lateral pressure. can get.

However, in the disking method, the clearance between the transmission cylinder and the glass rod, the thickness and material of the transmission cylinder,
Because the device-related elements such as the tightening pressure and interference of the ring-shaped rubber that seals high pressure and the setting conditions such as the peak pressure value, boost time, hold time, and streak load are complicatedly involved, An optical element cut from a streak having a specified cross section obtains the same cross-sectional shape, that is, a plurality of the same appearance,
It is very difficult to get the same weight.

Further, a so-called stopper ring system disclosed in Japanese Patent Application Laid-Open No. 07-132500, which prevents a glass rod from directly contacting a ring-shaped rubber and prevents the ring-shaped rubber from being damaged, is known. In this method, the ring-shaped rubber seals the pressing force in the inner circumferential direction applied from both end surfaces of the transmission cylinder and the pressing force in the axial direction trying to spread to both ends of the transmission cylinder, and cuts a plurality of pieces.

[0006] However, a glass bar having a streak provided with a constant load at a constant distance is inserted into the transmission tube before cutting, but the cut surface of the optical element cut near both ends of the transmission tube is smoother. However, there is a problem in that unevenness is generated, that is, the so-called undulation amount is increased, and weight variations are caused. In particular, the amount of undulation is likely to occur in the optical element material cut near the both ends of the transmission tube, and it depends on the diameter of the glass rod or the cutting thickness. Adversely affect the weight accuracy and appearance accuracy of the device.

Further, the optical element material cut near both ends of the transmission tube is apt to be uncut or defective in appearance, although the striations are provided with the same load as the vicinity of the center of the transmission tube. There was also.

[0008]

SUMMARY OF THE INVENTION In the present invention, in order to solve the problems of the conventional cutting technique, the above-mentioned disking method makes it possible to cut simultaneously at each of the designated cross-sections without fail and to provide a smooth surface. It is an object of the present invention to obtain a plurality of cylindrical glass materials having a small cut surface, particularly a cut surface similar to a mirror surface, and having a small weight variation.

[0009]

In order to achieve the above object, according to the present invention, a plurality of cross sections to be cut by an indenter are designated in advance on the outer surface of a rod-shaped workpiece made of a brittle material such as glass. The striations are provided, but the striations are repeatedly formed at an arbitrary unequal distance and further at an unequal load to obtain an optical element material.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to a rod-shaped glass made of a brittle material with little plastic deformation, an indenter having a striation to be cut on the outer surface of the glass rod, Means for providing the indenter and repeatedly providing the streak at any unequal distance; a side pressure transmission cylinder made of a material having a small Young's modulus for inserting the glass bar with the streak; and the glass rod Pressure medium filled between the material and the transmission cylinder, restraining the deformation of the transmission cylinder in the axial direction, having a means for forming a pressure chamber, to apply a side pressure along the outer periphery of the transmission cylinder, A method of cutting glass by lateral pressure, characterized by cutting along the plurality of streaks provided on the workpiece through the pressure medium, and the above configuration allows the glass to be cut inside the transmission cylinder. Each optical element material that has been fitted and cut into By varying pre notch distance portion measurement weight change relative to the amount, it has the effect of suppressing weight variation of each.

[0011] The invention according to claim 2 is characterized in that the glass rod is provided with the indenter as well as an indenter having a streak to be cut on the outer surface thereof, and the indenter is repeatedly provided at an arbitrary fixed distance or at every unequal distance. The method for cutting glass by lateral pressure according to claim 1, wherein the striations are provided by a load. By changing the load at the time of providing the striations in advance, it is possible to suppress the cutting failure. Has the effect of

An embodiment of a method for cutting glass according to the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a perspective view showing a method of forming a streak 2 on the outer surface of a glass bar 1, and FIG. 2 shows the streak 2 on the outer surface of the glass bar 1. Plan view, FIG. 3
1 is a sectional view of a cutting device used for cutting a glass rod.

Prior to the method of cutting the glass bar 1, prior to the cutting, an indenter previously positioned on a cutting position on the outer surface of the glass bar 1 as shown in FIG. The streaks 2 must be provided on the outer surface of the material 1 at the cutting position to easily induce cutting. The tip shape of the indenter is finish-polished on a flat surface using artificial diamond abrasive grains so as to have a constant unevenness at an arbitrary angle forming a pair, and the indenter has a load W _x , a set distance l _y , The striations 2 are made by abutting the glass bar 1 from the vertical direction at a speed V. The streak 2 as shown in FIG. 2 is adjusted at an angle parallel to the circumferential direction of the glass bar 1.

FIG. 3 shows an embodiment of a specific apparatus for applying a lateral pressure to the side surface of the glass bar 1 having streaks.
Will be described. In the figure, reference numeral 2 denotes a plurality of streaks provided on the outer surface of the glass rod 1 in advance to designate a cut surface. The glass bar 1 is fitted into the transmission tube 3 via the pressure medium 4, and the clearance between the glass bar 1 and the transmission tube 3 is several tens μm. Ring rubbers 5 called O-rings are externally fitted to both ends of the transmission cylinder 3, respectively.
Are fitted into the first support member and the second support member, respectively, and the holding member is brought into close contact with the transmission cylinder by moving and holding the holding member toward the first support member by a predetermined distance.

The ring-shaped rubber 5 divides the pressure in the inner circumferential direction applied from both end faces of the transmission cylinder 3 and the pressure in the axial direction that is going to spread to both ends of the transmission cylinder 3. In such a state,
The outer peripheral portion of the transmission cylinder 3 and the inside of the pressure vessel while being sandwiched between the two ring-shaped rubbers 5 fitted into the glass bar 1 via the first support member 6 and the second support member 7. The periphery can be sealed, and a pressure chamber can be formed. Therefore, the pressure increasing hole 1 is provided in the pressure chamber 9 of the pressure vessel.
A uniform lateral pressure P can be applied to the side surface of the glass rod 1 while hydraulic oil is poured from a hydraulic device (not shown) through the valve 0.

The principle up to the cutting of glass will be briefly described with reference to FIG. First, the glass rod 1
When the pressure medium 4 is filled into the clearance of the transmission cylinder 3 and the lateral pressure P is applied, a compressive stress is generated on the outer surface of the glass rod 1 and a tensile stress is generated in the center, and at the same time, the glass rod 1 The pressure medium 4 penetrates into the striations 2 on the outer surface, the pressure medium 4 acts as a wedge effect, and the friction generated between the transmission cylinder 3 which tends to expand in the axial direction and the glass rod 1 having a small expansion amount. The force allows cutting by lateral pressure.

Hereinafter, specific conditions according to the first embodiment will be described. Glass rod 1 has a Young's modulus of 82 × 10
⁴ kgf / mm ² solid cylinder with an outer diameter of 12 mm, used for lens molding. A streak 2 for designating a cut surface on the glass bar 1 is stamped by an indenter 12. The used indenter 12 is made of diamond and has a blade width of 1.6 m.
m. As shown in FIG. 5, the glass rod 1 is
And applying a load of W _x = 1000 g, V = 0.4 m
Pressing on the outer surface of the glass rod 1 at a speed of m / s, making a streak 2 and repeating these operations, the streak 2 becomes l _y
Eight places were provided in the axial direction of the glass bar 1 at an equal interval of mm. At this time, l _{y was} set to 3.0 mm, the length of the streak 2 was 450 μm, and all had the same shape as viewed with a stereoscopic microscope.

In the apparatus shown in FIG. 4, a glass rod 1 having a streak 2 was fitted into an acrylic resin transmission cylinder 3, and castor oil was sealed in the clearance as a pressure medium 4. The length of the transmission cylinder 3 is 25 mm, the ring-shaped rubber 5 has a wire diameter of 1.2 mm, and is fitted and adhered to predetermined positions of the first support member 6 and the second support member 7 respectively. The holding member 8 is moved toward the first support member 6 by about 1 mm, is pressed against the first support member 6, and compresses and deforms the ring-shaped rubber 5, thereby improving the airtightness of the pressure chamber.

As a result of this, as a result, the glass bar 1 is cut in a cross section passing through all the streaks 2 of the fitted glass bar 1 at a side pressure P of 9 kgf / mm ² and a boosting time of about 5 s. Although the cut surfaces were all mirror surfaces, the undulation amount of the cut surface became larger as the optical element material was cut near both ends of the transmission tube 3, and the weight of each optical element material was measured. The weight difference ΔW is
It was found that N = 1, 2, and 8th ones caused weight errors with good reproducibility.

Therefore, the pitch distance is calculated so that the weight difference ΔW = 0, and even if the cut surface has undulation,
The adjustment that approximates the ideal weight, that is, the uneven spacing adjustment of the streak was performed. l _y1 = 2.93 mm, l _y2 = 2.97
mm, l _y3 = 2.98 mm, and repeatedly cut under the above-mentioned setting conditions.
Eight optical element materials were obtained in one pressurization, and the weight variation of each was ± 9.7% of the average weight per piece at equal intervals. In this case, the result improved to ± 7.3% was obtained.

The results of this specific embodiment demonstrate the operation and effect of the cutting method of the present invention.

In the first embodiment, the pressure medium 4 filled between the glass bar 1 and the clearance
Castor oil was selected, but the same effect can be obtained regardless of the material of the glass rod 1 to be cut, as long as the medium has similar properties such as viscosity and wettability to castor oil.
It is also possible to carry out the method by adding a temporal change to the method of increasing the lateral pressure.

(Embodiment 2) FIG. 7 shows Embodiment 2 and is a plan view in which streaks 2 are provided on the outer surface of a glass rod 1 for each unequal load.

The indenter is a glass rod 1 of the method shown in FIG.
Mounted on the device to give a streak 2 on the outer surface of the load W _x,
The streak 2 is formed by contacting the glass bar 1 from the vertical direction at the set distance _Ly and the speed V. The load W
_x can be moved at specified intervals while changing the load irregularly, and a streak 2 is locally formed on the outer surface of the glass rod 1 at an angle parallel to the circumferential direction of the glass rod 1. Is provided in a standard manner.

The second embodiment will be specifically described below. The glass rod 1 used in the experiment had a Young's modulus of 103
This is a glass rod 1 for a lens which is a solid cylinder of × 10 ⁴ kgf / mm ² and an outer diameter of 7 mm and has the same shape as that of the first embodiment. While it is possible to move at the interval specified while changing irregularly placed a weight of the 100g units, first 12 positions to the spacing L _y = 3.0 mm in the glass rod 1 at equal load W _x = 700 g Was made. The length of the streak 2 was 270 μm at any point.

In the same apparatus as shown in FIG. 3, the glass rod 1 with the streaks 2 can be cut with a lateral pressure P of 9 kgf / mm ² , but the glass rod 1 located near both ends of the transmission cylinder 3 is cut. 1 is similar to the portion located near the center of the transmission tube 3, although the streak 2 was provided with the same load, appearance failure due to uncut or poor cutting occurred. Glass bar 1 located on the outer surface 2
The large, for inducing easily cut, the load W _x when providing the striations 2 W ₁ = W ₁₂ = 1000g addition,, W ₂ =
W ₁₁ was increased to 800 g, and further cutting experiments were performed. The length of the streak 2 is 380 μm and 320 μm, respectively.
m.

In this state, the glass bar 1 having the streaks 2 having different lengths is surely cut in all the cross sections at a lateral pressure P of 9 kgf / mm ² , and the cut surfaces are all mirror surfaces. Was. As described above, the method of cutting the glass rod 1 can provide the same operation and effect as in the first embodiment even in the above configuration.

In the case of the second embodiment, it is needless to say that the streak 2 can be obtained in the case of a plurality of (two or more) glass bars 1 as in the case of one glass bar 1. Furthermore,
In consideration of the first and second embodiments, a combined configuration can of course be implemented.

[0030]

As described above, according to the present invention, cutting does not involve cutting chips or noise, and cutting does not require any unnecessary time and energy. Cutting is performed, and a large amount of optical element material is obtained.

Further, the durability of the consumable member is improved, and
A plurality of cuts specified by the increase in the lateral pressure are reliably generated, so that the cut surface approximates a mirror surface, and it is possible to obtain a high-quality optical element material with less weight variation, and is inexpensive and high-quality. An optical element can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a method of forming a streak on a glass rod according to the present invention.

FIG. 2 is an explanatory diagram showing streaks on the outer surface of the glass rod of the present invention.

FIG. 3 is an explanatory view of an apparatus for implementing the method for cutting a glass rod according to the present invention.

FIG. 4 is an explanatory view showing a schematic principle of the cutting method of the present invention.

FIG. 5 is an explanatory view showing a cut state from a streak on the outer surface of the glass rod according to the first embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a difference between an ideal weight and a measured weight for each optical element material according to the first embodiment of the present invention.

FIG. 7 is an explanatory view showing striations on the outer surface of a glass rod according to Embodiment 2 of the present invention.

FIG. 8 is an explanatory view showing a cutting state from a streak on the outer surface of a conventional glass rod.

FIG. 9 is an explanatory diagram showing a difference between an ideal weight and a measured weight for each conventional optical element material.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 glass rod 2 streak 3 transmission cylinder 4 pressure medium 5 ring-shaped rubber 6 first support member 7 second support member 8 holding member 9 pressure chamber 10 boosting hole 11 pressure vessel 12 indenter 13 hydraulic oil 14 side pressure P15 Cut surface

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-266323 (JP, A) JP-A-6-198600 (JP, A) JP-A-7-132500 (JP, A) JP-A-5-1986 57699 (JP, A) JP-A-62-4600 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C03B 23/00-35/26

Claims (2)

(57) [Claims] 1. A rod-shaped glass made of a brittle material having little plastic deformation, an indenter for forming a streak to be cut on an outer surface of the glass rod, and the indenter, wherein the indenter is repeatedly provided at every unequal distance. A means for providing the streak, a side pressure transmission cylinder made of a material having a small Young's modulus for inserting the glass bar with the streak, and a pressure medium filled between the glass rod and the transmission cylinder. A means for constraining the deformation of the transmission cylinder in the axial direction, forming a pressure chamber, applying a side pressure along the outer periphery of the transmission cylinder, and being provided on the glass rod via the pressure medium. And cutting the glass along the plurality of striations. 2. An indenter, similar to an indenter having a streak to be cut on the outer surface of the glass bar, is provided with a streak by an unequal load repeatedly at an arbitrary constant or unequal distance. The method for cutting glass by lateral pressure according to claim 1, characterized in that: