JP2001347498A - Lateral pressure cutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the cutting surface of an optical element material obtained by a lateral pressure cutting method changeable to a flat shape or spherical shape by the set of the fitting distance of a lateral pressure transmitting cylinder to eliminate the problem peculiar to the optical element material obtained by lateral pressure cutting method. SOLUTION: A workpiece 1 having a plurality of streaks 2 formed on the circumferential surface is inserted to the lateral pressure transmitting cylinder 3 of a prescribed length the fitting distance of which is adjusted, a hydraulic pressurizing member 9 is moved to a normal position to apply a prescribed lateral pressure to the lateral pressure transmitting cylinder 3, whereby the workpiece 1 is radially cut.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for cutting a workpiece by lateral pressure.
For example, rods used when molding a glass optical element such as a lens by pressing are used in a field where a high-quality cut surface is required and cutting of a workpiece suitable for mass production is required. TECHNICAL FIELD The present invention relates to a side pressure cutting device used in a step of cutting a workpiece such as long glass.

[0002]

2. Description of the Related Art Conventionally, mass-production techniques for aspherical glass lenses by a molding method suitable for mass production of aspherical glass lenses have been established and are up to the present day. Most of optical element materials used in molding such glass lenses have a spherical surface, a ball, or a polished cylindrical shape.

[0003] As a method of processing a columnar optical element material, a bar material is cut, polished, wrapped, and polished to obtain an optical element material having mirror surfaces at both end surfaces. Has proposed a new processing method using material destruction by lateral pressure.

[0004] This new processing method is called a lateral pressure cutting method,
Japanese Patent Application Laid-Open No. 61-2663, which cuts brittle bars or the like by side pressure without using a conventional tool such as a diamond cutter.
In the method disclosed in Japanese Patent Publication No. 23, no chips or noise are generated at the time of processing, the time required for processing and the processing energy are small, and the lateral pressure during processing is related to the size of the workpiece. This is a constant value, and the cut surface is smoothed, which has many advantages not found in the conventional processing method.

[0005] However, the lateral pressure cutting method uses a clearance between the lateral pressure transmitting cylinder and the brittle rod, the thickness and material of the transmitting cylinder,
Device-related elements such as the tightening pressure and interference of the ring-shaped rubber that seals high pressure and setting-related elements such as the rising pressure value, boosting time, set pressure holding time, and streak load are complicatedly involved. An optical element material obtained by cutting a plurality of cross-sections from a specified streak has the same shape, that is, it is very difficult to obtain an optical element material having a plurality of appearances, the same appearance, and the same weight.

The variation in weight of the optical element material cut near both ends of the side pressure transmission cylinder has a problem that the cut surface is not smooth but largely undulates depending on the fixing position of the brittle rod.

However, since the cut surface and the edge of the side surface of the optical element material obtained by the present cutting method are sharp boundaries at an angle of 90 degrees, the boundary of the material is partially formed at the time of press molding. If chipping occurs, the so-called chipping occurs suddenly, and if the debris is pressed while entering, it remains on the lens surface of the optical element, or if transfer failure such as air accumulation occurs, It cannot be used as an optical element and will be discarded as a result.

The optical element material obtained by the side pressure cutting method is used as, for example, a press-molded glass material for an aspherical optical element, and the transfer surface of a mold used for molding is spherical or spherical in submicron units. When molding an optical element material that has an aspherical shape but has two cut surfaces flat, the gas enclosed between the transfer surface and the cut surface of the optical element material is discharged during molding, so several times during the pressing process. It is necessary to repeat the compression and decompression of the mold, which not only deteriorates the transfer surface of the mold, it also takes a long molding time, and also reduces the life of the expensive mold during continuous production. That is the current situation.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the problems of the conventional cutting technique, and an optical element material having a cut surface approximate to a desired optical element shape can be obtained. It is an object of the present invention to obtain a plurality of high-quality optical elements by press molding and to prolong the life of a mold required for molding.

[0010]

In order to achieve the above object, a lateral pressure cutting device according to the present invention is provided with a pressure vessel for applying a lateral pressure to a solid cylindrical workpiece and radially cutting the workpiece. A side pressure transmission cylinder, pressure generating means for applying pressure,
An apparatus comprising: a pressure rising line connecting a pressure vessel and pressure generating means; and means for changing a length of a side pressure transmission cylinder according to an interval between longitudinal streaks on an outer peripheral surface of the workpiece. The cutting surface can be cut into a flat or spherical shape.

Further, the side pressure cutting device of the present invention is characterized in that the optical element cut in the radial direction is changed by changing the fitting distance from both ends of the side pressure transmission cylinder to the closest streak on the outer peripheral surface of the workpiece. It is characterized in that a plurality of cut surfaces on both sides of the material are obtained in a shape similar to the convex and concave optical elements.

Further, the lateral pressure cutting device of the present invention cuts the fitting distance from both ends of the lateral pressure transmission cylinder to the closest streak on the outer peripheral surface of the workpiece and an arbitrarily set regulation position of the workpiece. Alternately every number of times, one of the cut surfaces of the optical element material cut in the radial direction is a convex shape, and the other opposing cut surface is obtained in a shape similar to a planar optical element, and a plurality of pieces are obtained. Features.

Further, the side pressure cutting device of the present invention is to form an optical element material having a shape similar to the optical element obtained by the side pressure cutting by a single press to obtain a desired optical element. Features.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 shows a lateral pressure cutting device according to Embodiment 1 of the present invention, which is used when cutting a rod-shaped workpiece 1 made of a brittle material.

When cutting a workpiece using this side pressure cutting device, the cutting position of the workpiece 1 is determined by using an indenter (not shown) which has been placed on the cutting position on the outer peripheral surface of the workpiece 1 before cutting. Is provided on the outer peripheral surface of the substrate for easily inducing cutting.

Here, the tip shape of the indenter is polished at the same arbitrary angle from both sides, and the indenter applies an arbitrary load specified to the workpiece 1 from the vertical direction to the workpiece 1 so that the workpiece 1 The streaks 2 are locally formed at predetermined intervals in the axial direction. The streak 2 is a work 1 in advance to specify the cut surface.
Are formed on the outer peripheral surface of the workpiece 1, and the striations 2 are formed in the radial direction on the outer peripheral surface of the workpiece 1, and are provided locally at an arbitrary set distance.

As shown in FIG. 1, a side pressure cutting device M1 according to this embodiment includes a pressure vessel 10 and a pressure vessel 1
Side pressure transmission cylinder 3 of arbitrary length attached inside 0
And a pair of pressure seal members 5 interposed between the first and second metal members 6 and 7 disposed on both sides of the side pressure transmission tube 3, and the side pressure transmission tube of the second metal member 7. 3 A metal cylinder member 8 having a designated length in a state of being in close contact with the surface side opposite to the contact surface side, and a first metal member 6 slidably mounted inside the pressure vessel 10 are axially pressed. And a pressure generating device 12 connected to the pressure vessel 10 and applying a predetermined pressure to the outer peripheral side surface of the side pressure transmission cylinder 3 and the hydraulic pressure applying member 9.

The pressure generating device 12 includes a hydraulic pump 13 and a pressure intensifier 14. The pressure intensifier 14 communicates with the outer peripheral surface of the side pressure transmission cylinder 3 via the first pressure increasing line 11, while the hydraulic pump 13 is Hydraulic pressurizing member 9
Communicating with the back side of the step part.

The above configuration is substantially the same as the configuration of the conventional lateral pressure cutting device shown in FIG. 11, and the workpiece 1 on which the streaks 2 are formed is transferred to the lateral pressure transmitting cylinder 3 via the pressure medium 4. The clearance between the workpiece 1 and the side pressure transmission cylinder 3 is set to several tens of μm.

The pressure seal members 5 disposed at both ends of the side pressure transmission cylinder 3 are made of an elastic material and are fitted into recesses formed in the first and second metal members 6, 7, respectively. The hydraulic pressurizing member 9 retracted when the workpiece 1 is inserted in order to improve the airtightness of the pressure chamber of the first embodiment, presses the first metal member 6 with the second metal member 7 and the metal cylinder member by the pressing force of the hydraulic pump 13. 8
The pressure seal member 5 is moved to the side by a certain distance, and the pressure sealing members 5 receive a pressure deformation force, so that the airtightness of the pressure chamber is increased.

The pressure seal member 5 applies a pressure applied between the outer peripheral surface of the side pressure transmission cylinder 3 and the inside of the pressure vessel 10 via the pressure medium 4 to release the rod-shaped workpiece 1 in the axial direction, and the rod-shaped workpiece. It is arranged to hermetically seal the pressure of the object 1 to leak in the radial direction.

Further, between the outer peripheral surface of the rod-shaped workpiece 1 and the inner peripheral surface of the side pressure transmission cylinder 3, a high-viscosity liquid, for example, castor oil, is in close contact with the entire surface.
The high pressure generated in 3 can be transmitted to the outer peripheral surface of the rod-shaped workpiece 1 through the pressure medium 4, the side pressure transmission cylinder 3, and the high-viscosity liquid without loss.

In such a state, the outer peripheral surface of the side pressure transmission cylinder 3 and the pressure vessel 10 in a section sandwiched by the pair of pressure seal members 5 fitted through the first metal member 6 and the second metal member 7. The inner peripheral portion becomes airtight, and a pressure chamber is formed in the pressure vessel 10. Therefore, the pressure vessel 1
By flowing the operating oil from the pressure (oil pressure) generator 12 into the zero pressure chamber via the pressure raising line 11, a uniform and high lateral pressure can be applied to the outer peripheral surface of the workpiece 1.

The portion on which the lateral pressure is applied to the outer peripheral surface of the workpiece 1 is only the portion that is fitted into the lateral pressure transmission tube 3, and like the transmission cylinder 3, the first and second metal members 6, 7 It is possible to keep a state where almost no pressure is applied to the outer peripheral side surface of the workpiece 1 in the fitting portion fitted in the metal cylinder member 8.

FIG. 2 shows a state in which the workpiece 1 at both ends of the side pressure transmission cylinder 3 is cut off from the state of cutting at the center of the side pressure transmission cylinder 3.

When the streak 2 is considered as a reference position, the workpiece 1 is symmetrical in the length direction from the reference position.
No lateral pressure is applied to the outer peripheral portion of the motor.

That is, when considering the cutting of the streak 2b, the outer peripheral surface to be cut on the right side as viewed in FIG. 2 between the streak 2a and the streak 2b and the left side cutting between the streak 2c and the streak 2b An equal side pressure is applied to the outer peripheral surface to be performed by the same surface integral via the side pressure transmission cylinder 3.

On the other hand, when considering the cutting of the streak 2a, the outer peripheral surface of the workpiece 1 on the right side of the streak 2a inserted into the side pressure transmission cylinder 3 between the streak 2a from the tip (not shown) and the streak 2a
Since the lateral pressure applied for cutting is unevenly applied to the outer peripheral surface between the groove 2b and the groove 2b, the cut surface of the workpiece 1 on the right side of the groove 2a has a convex surface and the opposite surface of the groove 2a is concave. When the cut 2c is further considered on the shape surface, the outer peripheral surface of the workpiece 1 on the left side of the not-shown streak 2c and the outer peripheral surface between the streak 2b and the streak 2c are loaded for cutting. As a result, a phenomenon occurs in which the cut surface of the workpiece 1 on the left side of the streak 2c becomes convex and the opposing surface of the streak 2c becomes concave. This is a phenomenon caused by the fact that the energy required for cutting does not evenly apply the streak to the boundary.

As the insertion distance of the workpiece 1 is actually set smaller, the outer peripheral surface of the workpiece 1 becomes more different in the outer peripheral surface area to be inserted into the side pressure transmission cylinder 3, and the cut surface is shifted in the longitudinal direction of the workpiece. It has been found that the shape of the cut surface is spherical because the difference in the cutting stress generated symmetrically is large.

Hereinafter, specific conditions in the side pressure cutting performed by using the side pressure cutting device having substantially the same configuration as the conventional configuration will be described.

The workpiece 1 has a Young's modulus of 1.08 × 10 ⁴ kgf / mm ² ,
A solid cylindrical optical glass rod having an outer diameter of about 9 mm and used for molding a lens was used. A streak 2 for designating a cut surface on the workpiece 1 was stamped with an indenter (not shown). A load of 1000 g or less is applied to the used workpiece 1 at a uniform distance of 4 mm in the axial direction of the outer peripheral surface to apply a streak 2
Were formed. The length of the streak is 350 μm,
All had the same shape.

As shown in FIG. 1, a workpiece 1 on which streaks 2 were formed was fitted into a hollow cylinder-shaped side pressure transmission cylinder 3 made of methacrylic resin. Since a known high-viscosity oil, such as castor oil, is used as a medium sealed between the workpiece 1 and the side pressure transmission cylinder 3, the high-viscosity oil and fat does not flow out from both ends of the side pressure transmission cylinder 3, and a sealed state is maintained.

The length of the side pressure transmitting cylinder 3 is about 21 mm, and the pressure sealing member 5 is made of a ring-shaped rubber having a wire diameter of 1.2 mm and is positioned at a predetermined position of the first metal member 6 and the second metal member 7. Each was fitted. The distance at which the tip and the sixth piece engage with the side pressure transmitting cylinder 3 is 2.5 mm each.

The material of the first metal member 6, the second metal member 7, and the metal cylinder member 8 was carbon tool steel. Further, the clearance accuracy of the inner diameter between the workpiece 1 and the first metal member 6, the second metal member 7, or the metal cylinder member 8 is several tens μm so as to be substantially the same as the clearance precision of the side pressure transmission cylinder 3.
m. This clearance is provided to prevent the workpiece 1 from being caught in the side pressure transmission cylinder 3 when the workpiece 1 is inserted or cut and then discharged.

The hydraulic pressurizing member 9 was actuated by operating pressure at a circulating pressure of 1.2 kgf / mm ² received from the hydraulic pump 13, and moved instantaneously by a gap between the stopper 17 and the spacer 15.
The mechanism for setting the movement amount is a method of inserting a spacer 15 having a thickness of about 10 mm and considering surface roughness, and the movement amount is about 1 mm. The thickness of the spacer 15 can be changed as needed.

Further, the side pressure cutting device having the above configuration is operated so that the cutting pressure of the first pressure raising line 11 is 8.5 kgf / mm ² , the pressure raising time is 5 seconds, and the holding time is 3 seconds. As a result of reducing the pressure, seven optical element materials 16 were obtained in one cutting step, but all cut surface shapes were cut at right angles to the length direction of the workpiece 1.

Therefore, in the side pressure cutting device according to the first embodiment of the present invention shown in FIG. 1, the length of the side pressure transmission cylinder 3 is changed so that the cut surface of the workpiece 1 is spherical.

The length 1 of the side pressure transmitting cylinder 3 is the cut thickness d of the workpiece, the number of cuts n, and the distance from either end of the side pressure transmitting cylinder to the closest streak of the fitting portion of the same side pressure transmitting cylinder 3. When m is set, l = (n-1) d + 2m. In addition, several metal cylinder members 8 having several lengths are prepared in advance so that the length of the pressure chamber 4 is kept the same as that of the conventional method in accordance with the change in the length of the side pressure transmission cylinder 3. The length of the metal cylinder member 8 at this time may be a value obtained by adding the length of the side pressure transmission cylinder 3 used in the present embodiment to the length of the conventional side pressure transmission cylinder 3. This time, the side pressure transmission cylinder 3 was arranged so that it might become a contrast centering on the boost line 11.

Based on the above configuration, the length 1 of the side pressure transmitting cylinder 3
Since the fitting distance is set to m = 0.8 mm and the number of cuts is set to n = 5, 1 = 17.6 mm. The metal cylinder 8 has a length of 1.7 mm and is inserted into the pressure vessel 10.

In the present embodiment, the total amount of movement of the hydraulic pressure member 9 from the retracted position to the specified position is 1 mm as described above.
The circulation pressure of the hydraulic pump 13 was set at 1.2 kgf / mm ² .

After moving the hydraulic pressurizing member 9 to the specified position, it was operated under cutting conditions of a cutting pressure of 8.5 kgf / mm ² , a boosting time of 5 seconds and a holding time of 3 seconds, and as shown in FIG. As a result of the decompression, several biconvex optical element materials and several plano-concave optical element materials are obtained alternately.The curvature of the spherical surface is approximately 125 mm, and the element weight is slightly reduced. Although there was some variation, they were all at a level with no quality problem.

In the present embodiment, it is possible to appropriately select and set the value of the lateral pressure, the boosting time, or the lateral pressure setting holding time in response to the change of the object to be processed. The spherical surface R of the cut surface can be arbitrarily changed by changing the fitting distance m of the side pressure transmission tube 3 from the position of the striation 2 on the workpiece, that is, by appropriately selecting the length of the side pressure transmission tube 3. .

As described above, according to the lateral pressure cutting method of the present embodiment, the length of the lateral pressure transmitting cylinder 3 is arbitrarily changed while calculating the fitting distance, so that the cut surface of the workpiece has a desired spherical shape. Can be obtained. (Second Embodiment) FIG. 4 shows a cross section of a lateral pressure cutting device M2 according to a second embodiment of the present invention.

The structure of the side pressure cutting device M2 is the same as that of the first embodiment.
Is basically the same as that of the side pressure cutting device M1, except that the length of the side pressure cutting tube 3 and the length of the metal tube member 8 are different.

The workpiece 1 has a Young's modulus of 1.08 × 10 ⁴ kgf / mm ² ,
A solid cylindrical optical glass rod having an outer diameter of about 9 mm and the same as that of the first embodiment was used. The streak 2 is also stamped with an indenter (not shown), and d = 4 m in the axial direction of the outer peripheral surface of the workpiece 1.
A load of 1000 g or less was applied at equal intervals of m to form some streaks 2. The length of the streak is also the same as in the first embodiment. Since the side pressure transmission cylinder 3 used was 12 mm in length,
The distance from the first position of the streak 2 to the side pressure transmission tube 3 from the tip of the workpiece 1 is 2 mm, and the distance from the third position of the streak 2 to the side pressure transmission tube 3 is 2 mm. I adjusted the position of object 1 and wanted to boost.

The cutting pressure at the time of pressure increase is 8.5 kgf / mm ² ,
When the boosting time was 5 seconds and the holding time was 3 seconds, and the same cutting conditions were used as in the first embodiment, three optical element materials were obtained. The angle was perpendicular to the axial direction, and the cross-sectional shapes were almost the same.

Therefore, in the lateral pressure cutting device M2 according to the present embodiment shown in FIG. 4, the cut thickness d of the workpiece is d = 4 mm, the number of cuts n = 3, so that the cut surface of the workpiece 1 is spherical.
Assuming that the insertion distance between the shortest streaks is m = 0.8 mm from both ends of the side pressure transmission tube to the center side, the length 1 of the side pressure transmission tube 3 is 1 = from the formula shown in the first embodiment. 9.6mm.
Further, the metal cylinder member 8 is added to the pressure vessel 10 by adding a length of 2.4 mm from the above-described embodiment.

In the above configuration, the cutting pressure is 8.5 kgf / mm ² ,
The workpiece 1 was operated under cutting conditions with a pressure rising time of 5 seconds and a holding time of 3 seconds, and as shown in FIG.
6e and bi-concave optical element materials 16b and 16d, several bi-convex optical element materials and several bi-concave optical element materials are obtained alternately, and the spherical curvature R ≒ At 125 mm, each element was at a level with no problem in quality.

In the present embodiment, since bi-convex and bi-concave optical element materials can be obtained from a solid cylindrical workpiece, either of them is used except for the case where both shapes of optical element materials are used. When an element having such a shape is not required, it is possible to cope with a so-called unequal pitch setting that shortens the unnecessary streak distance. (Embodiment 3) FIG. 6 shows a lateral pressure cutting device M3 according to Embodiment 3 of the present invention.

The configuration of the lateral pressure cutting device is basically the same as the configuration of the lateral pressure cutting device M2 according to the second embodiment.
The only difference is that the cutting pressure and the setting position of the workpiece can be changed for each number of cuts.

Hereinafter, specific conditions in the lateral pressure cutting performed by using the lateral pressure cutting device M3 in the present embodiment will be described.

The workpiece 1 used in the study had a Young's modulus of 1.03
A solid cylindrical optical glass rod of × 10 ⁴ kgf / mm ² , outer diameter of about 6 mm and length of 120 mm, which is finished to the same shape accuracy as that used in the first embodiment. 1
Streak 2 provided on the outer peripheral surface of the load is 900g, pitch distance
4 mm, and the shape of each streak 2 is almost the same. The length of the side pressure transmission cylinder 3 was 18 mm, and the circulation pressure was set at 1.8 kgf / mm ² .

As shown in FIG. 7, the length 1 of the side pressure transmission tube 3 is 5.8 mm so that the fitting distance is 0.9 mm, and the length of the metal tube member 8 is 12.2 mm. 8.Pressure
The unnecessary tip material 16a ₁ and the optical element material 16b ₁ were cut at 0 kgf / mm ² , a pressure rise time of 3 seconds, and a set holding time of 3 seconds.

[0054] During the second cutting, after discharging the unnecessary tip material 16a ₁ of the workpiece 1, as 1.5mm regulating the position of the workpiece 1 from the first in the state of inserting the optical element 16b ₁ of the cut already discharged 7.5kgf / m lower than the initial pressure after moving and fixing to the side
When the cutting was performed with m ² , a boosting time of 3 seconds, and a set holding time of 3 seconds, the workpiece 1 was cut only at the streak 2 fitted into the center of the side pressure transmission cylinder 3, and the optical element material 16 c ₁ was cut. Obtained. These cut, the cut surface of the optical element material 16c ₁ is convex-sided curvature R ≒ 100 mm, the other cut surface becomes perpendicular planar shape in the longitudinal direction of the workpiece 1, the desired good optical Several optical element materials were obtained. By repeating this cutting procedure several times, ten desired optical element materials can be obtained from one workpiece 1.

In this embodiment, if the fitting distance is changed in the same manner as in the first embodiment, various spherical cut surfaces can be obtained, and the setting position of the workpiece 1 can be changed. The same effect can be obtained. Further, the plane cut surface can be corrected to a higher quality plane state than the plane state before processing by performing a plane polishing process after the end of the cutting.

As described above, according to the lateral pressure cutting device of the present embodiment, the length of the lateral pressure transmission cylinder 3, the lateral pressure to be loaded, and the setting position of the workpiece 1 are repeatedly performed while calculating the fitting distance. The cut surface of the workpiece has an effect that a desired spherical shape or planar shape can be obtained. (Embodiment 4) FIGS. 8, 9, and 10 show a process of processing an optical element, an optical element material, and an obtained optical element according to Embodiment 4 of the present invention. Note that the same reference numerals are given to the contents described in FIGS.

Hereinafter, a method of processing the optical element material obtained by the side pressure cutting method will be specifically described.

The optical element material 16b or 16c obtained by the lateral pressure cutting in the first embodiment is used as one of the lenses for a video movie, and the optical element material 16b obtained by the lateral pressure cutting in the second embodiment.
₁ is used as a collimating lens for compact disc players and digital video discs.

These optical element materials 16b, c, b
₁ is not shown in detail, but both cut sides are finished with the required accuracy.

Further, the first molding die 2 used in molding
The spherical, aspherical, or flat transfer surfaces of the first and second molding dies 22 are each processed into a desired shape with submicron precision, and fitted into the upper and lower inner diameters of the body mold.

In the above configuration, the optical element material having a cut surface obtained by the conventional lateral pressure cutting method and having a planar shape is enclosed in a molding die 6a, and heated, pressed and cooled. In some cases, the chip of the optical element material is suddenly partially chipped on the cut surface and the side edge, and the chipped chip enters the transfer surface of the obtained optical element 20, resulting in defective transfer.

Further, in order to improve the transferability after molding of a conventional optical element material having a cut plane, a general molding method in which pressurization and depressurization are repeated at the time of pressing is performed continuously. The portion where the transfer surface of the first molding die 21 or the second molding die 22 contacts the edge of the optical element material is scratched at an early stage, preventing deformation of the optical element material during heating, Scratches were transferred to the appearance of the optical element 20 to cause defective appearance, and the mold could not be used at an early stage.

[0063] Therefore, the optical element material 16b obtained in the second and third embodiments of the present invention, 16c, the molding using 16b ₁ was carried out. A biconvex optical element material 16 shown in FIG.
c is a biconcave optical element material 16 in a molding die 23a.
b The molding die within 23b, also the optical element material 16c ₁ of the plano-convex shape in a state of being encapsulated in the molding die in 23c, heating,
By applying pressure and cooling, each of the optical elements 20
a, 20b and 20c are obtained respectively.

In the pressing step during the molding process, the cut surface of the optical element material has a shape similar to the transfer surface of the mold in advance. Since the deformation almost ends when the material is heated, the gas sealed between the transfer surface of the mold and the cut surface of the optical element material is lost when the material is heated. As a result, chipping of the edge of the optical element material which occurs during pressing is drastically reduced, the life of the first and second molds 21 and 22 is extended by about 5 times as compared with the conventional one, and the transfer accuracy is improved with optical elements of other shapes. There was no difference from the time when the material was molded, and the performance was not problematic for the required optical characteristics.

As described above, according to the lateral pressure cutting method in consideration of the processing method of the optical element material according to the present embodiment, the optical element materials 16b, 16c approximate to the optical elements 20a, 20b, 20c of the shape desired for each application. , 16c ₁ allows mass production of optical elements of the same shape,
Quality loss and damage to the mold can be minimized.

[0066]

As described above, according to the lateral pressure cutting device of the present invention, the arrangement of the lateral pressure transmitting cylinder and the boosting line for applying the lateral pressure, the lateral pressure to be applied, and the position of the streak on the workpiece are defined. Accordingly, the curvature of the surface of the optical element to be cut can be arbitrarily set and managed.

Further, in the subsequent molding step, since an optical element having a shape close to the finished product has been obtained in advance, it is possible to avoid mold failure due to mixing of debris and problems of poor transfer such as air pockets. The molding can be performed easily, and the life of the mold can be prolonged.

[Brief description of the drawings]

FIG. 1 is a side pressure cutting device M1 according to a first embodiment of the present invention.
Overall configuration diagram

FIG. 2 is a cross-sectional view schematically showing a side pressure applied to a workpiece in a pressure chamber.

FIG. 3 is a cross-sectional view showing a pressure chamber when a biconvex or plano-concave optical element material according to the first embodiment of the present invention is obtained.

FIG. 4 is a side pressure cutting device M2 according to a second embodiment of the present invention.
Overall configuration diagram

FIG. 5 is a cross-sectional view showing a pressure chamber when a biconvex or biconcave optical element material according to a second embodiment of the present invention is obtained.

FIG. 6 is a side pressure cutting device M3 according to a third embodiment of the present invention.
Overall configuration diagram

FIG. 7 is a sectional view showing a pressure chamber when a plano-convex optical element material according to a third embodiment of the present invention is obtained.

FIG. 8 is a cross-sectional view showing a processing step of manufacturing an optical element using the optical element material obtained by the side pressure cutting of the side pressure cutting apparatus of FIGS. 4 and 6;

FIG. 9 is an external shape view of an obtained optical element material according to the second and third embodiments of the present invention.

FIG. 10 is an external view of an optical element obtained according to a fourth embodiment of the present invention.

FIG. 11 is an overall configuration diagram of a conventional side pressure cutting device.

FIG. 12 is a sectional view showing a pressure chamber when a conventional optical element material is obtained.

FIG. 13 is a cross-sectional view showing a processing step of manufacturing an optical element using an optical element material obtained by side pressure cutting of a conventional side pressure cutting device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Workpiece 2 Streak 3 Workpiece 4 Pressure medium 5 Pressure seal member 6 First metal member 7 Second metal member 8 Metal cylinder member 9 Hydraulic pressurizing member 10 Pressure vessel 11 First booster line 12 Pressure generator DESCRIPTION OF SYMBOLS 13 Hydraulic pump 14 Intensifier 15 Spacer 16a, 16a ₁ Tip material of work 1 16b, 16d, 16b ₁ Biconcave optical element material 16c Biconvex optical element material 16c ₁ Planoconvex optical element material 17 Stopper 20a Biconvex optical element 20b Biconcave optical element 20c Planoconvex optical element 21 First molding die 22 Second molding die 31 Second boosting line

Claims (4)

[Claims] 1. A pressure vessel for applying a lateral pressure to a solid cylindrical workpiece to cut the workpiece in a radial direction, a lateral pressure transmitting cylinder, a pressure generating means for applying a pressure, a pressure vessel and a pressure vessel A pressure boosting line connecting the generating means, and means for changing the length of the side pressure transmission cylinder according to the interval between longitudinal streaks on the outer peripheral surface of the workpiece, wherein the cut surface of the workpiece is A side pressure cutting device characterized in that it can be cut into a spherical shape. 2. The cut surfaces on both sides of the optical element material cut in the radial direction are changed by changing a fitting distance from both ends of the side pressure transmission cylinder to the closest streak on the outer peripheral surface of the workpiece. With a shape similar to the shape and concave optical element,
The side pressure cutting device according to claim 1, wherein a plurality of the pressure cutting devices can be obtained. 3. The fitting distance from both ends of the side pressure transmission cylinder to the closest streak on the outer peripheral surface of the workpiece and an arbitrarily set regulation position of the workpiece are alternately changed for each number of cuts.
2. The optical element material according to claim 1, wherein one of the cut surfaces of the optical element material cut in the radial direction has a convex shape, and the other opposing cut surface has a shape similar to a planar optical element, and a plurality of cut surfaces can be obtained. Side pressure cutting device. 4. A side pressure cutting device which forms an optical element material having a shape similar to an optical element obtained by the side pressure cutting by a single press to obtain a desired optical element.