JP2000072465A - Side pressure cutting method and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain high-quality optical element blanks having high weight accuracy without loss at the time of continuous cutting, to make the regulation position of a hydraulic pressurizing member finer and to drastically shorten the time for indexing cutting conditions by enhancing the durability of a side pressure transmission cylinder, pressure sealing member, etc. SOLUTION: A workpiece 1 formed with plural streaks 2 on its outer peripheral surface is inserted into the side pressure transmission cylinder 3 mounted within a pressure vessel 11 and the hydraulic pressurizing member 8 for pressurizing and deforming a pair of the position sealing members 5 disposed on both sides of the side pressure transmission cylinder 3 is mounted freely slidably between a retreat position and a regulated position. The position of the hydraulic pressurizing member 8 is detected. The detected position signal of the hydraulic pressurizing member 8 is compared with the position command signal for setting the regulated position. While the difference between the position signal and the position command signal is controlled so that the difference is made zero, the hydraulic pressurizing member 8 existing in the retreat position is moved to the regulated position and thereafter, the prescribed side pressure is applied to the side pressure transmission cylinder 3, by which the workpiece 1 is cut in a diametral direction. The hydraulic pressurizing member 8 is moved from the regulated position to the retreat position after the cutting.

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 method and an apparatus used in a step of cutting a workpiece such as a 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 the optical element materials used in the molding of such glass lenses have a polished ball or polished column 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,
No chips and noise are generated during processing, the time required for processing and the processing energy are very small, and the lateral pressure during processing is constant regardless of the size of the workpiece. Has many advantages not found in conventional processing methods, such as being smooth and, in particular, a mirror surface for glass and ceramics.

FIG. 8 shows an apparatus using the lateral pressure cutting method. In order to prevent direct contact between the workpiece 1 and the pressure sealing member 5 and to prevent the pressure sealing member 5 from being damaged, FIG. This is an apparatus employing a so-called stopper ring system using one metal member 6 and a second metal member 7 (see Japanese Patent Application Laid-Open No. 7-132500).

In the stopper ring system, while a pair of pressure seal members 5 are deformed, a plurality of cuts are applied by applying a tensile force in the axial direction on the bar-shaped workpiece 1 and a pressing force in the radial direction on the workpiece 1. This is a method in which each pressure seal member 5 is fitted in a state surrounded by a step portion of the first metal member 6 or the second metal member 7 so as not to directly contact the workpiece 1. .

[0008] As shown in FIG. 8, the side pressure cutting method includes a pressure vessel 11 connected to a pressure increasing line 12 and a pressure vessel 11.
A pair of metal members 6 and 7 provided therein, a side pressure transmission tube 3 having a length corresponding to one cut, a pair of pressure seal members 5 provided at both ends of the side pressure transmission tube 3, A hydraulic pump 14 for supplying hydraulic oil to a pressure chamber between the pair of pressure seal members 5 from the pressure generating device 13 in which the hydraulic pump 14 and the intensifier 15 are incorporated, and one side of the first metal member 6. The hydraulic pressurizing member 8 is in contact with and operates with the circulating pressure from the hydraulic pump 14, and the spacer 17 determines the amount of movement of the hydraulic pressurizing member 8.

A bar-shaped workpiece 1 is provided with a streak 2 in advance, and a portion of the streak 2 of the workpiece 1 is inserted to a position opposed to a pressure boosting line 12 in a side pressure transmission cylinder 3 of a pressure vessel 11. You. Then, after the pressure chamber is brought into a highly airtight state by the movement of the hydraulic pressurizing member 8, when hydraulic oil is introduced from the pressure generating device 13 into the pressure vessel 11 through the pressure increasing line 12, the work piece 1 Compressive stress is generated on the outer peripheral surface via the side pressure transmission cylinder 3, and tensile stress is generated at the center. This tensile stress increases in proportion to the applied pressure. When the tensile stress exceeds the tensile strength of the workpiece 1, the workpiece 1 is broken and cut at that point. At this time, the striations 2 located in the side pressure transmission cylinder 3 are cut almost at the same time, although there is a time difference. The pressure medium 4 is filled between the workpiece 1 and the side pressure transmission cylinder 3 so that the lateral pressure is uniformly applied to the entire outer periphery of the workpiece 1.

[0009]

However, the following problems occur in the lateral pressure cutting method using the conventional lateral pressure cutting device having the above configuration. In the stopper ring method, the pressure is reduced after the pressurization and cutting, but the above-described method in which the pressurization and the depressurization are repeated is called a disking method, in which the bar-shaped workpiece 1 is repeatedly expanded and contracted in the radial direction or the axial direction. Accordingly, there is a problem that the pressure vessel constituent members such as the pressure seal member 5 necessary for maintaining the airtightness are deteriorated.

The degree of deterioration of the components of the pressure vessel progresses as the applied pressure increases, and as the time for increasing the pressure to the set pressure is set shorter, the degree of deterioration advances.

Further, as a factor for promoting the deterioration of the pressure vessel constituent members, it is considered that the moving state of the hydraulic pressure applying member 8 influences. In particular, the moving speed and the pressing force of the hydraulic pressure applying member 8 or the specified position set when the hydraulic pressure applying member 8 generates a high pressure have a great effect. In addition, as a cutting process at the present stage, an unnecessary impact force is applied to the pressure seal member 5 or the side pressure transmission cylinder 3 in a state where the pressure is not increased, so that the deterioration of the pressure vessel constituting member is unnecessarily promoted. I will.

The role of the hydraulic pressurizing member 8 is roughly divided into two. The first point is an operation of moving the hydraulic pressurizing member 8 to a retreat position by a set distance by hydraulic pressure so as not to apply unnecessary restraining force to the pressure seal member 5. This operation is performed when the workpiece 1 is inserted to a predetermined position in the pressure vessel 11 and when the workpiece 1 is discharged after the cutting is completed. The role of the second point is to increase the airtightness of the pressure chamber at the time of pressure increase, and the hydraulic pressurizing member 8 is moved to a specified position by a predetermined distance with a pressure set by the hydraulic pressure, and then held at that position. Is done. This operation is performed only between steps including immediately before and immediately after the step-up to a high pressure.

In order to actually increase the airtightness of the pressure chamber,
The pressure seal member 5 is connected to the inner surface of the pressure vessel 11 and the metal members
Is pressed into the space sandwiched between the stepped portion of
The space needs to be deformed around 20%. It should be noted here that the optimum specified position must be determined. If the hydraulic pressurizing member 8 moves to the pressure seal member 5 side more than the optimal specified position, the airtightness of the pressure chamber is increased, but the pressure applied to the pressure seal member 5 and the side pressure transmission cylinder 3 is reduced. As a result, the deterioration of these pressure vessel components occurs early even with a small number of uses. Conversely, if the hydraulic pressure applying member 8 moves less than the optimum specified position, the airtightness of the pressure chamber becomes low, so that the pressure seal member 5 is less deformed or the pressure seal member 5 and the side pressure transmission cylinder 3 may have a slight gap. When the pressure is repeatedly increased in such a state, the lateral pressure tends to escape between the outer peripheral portion of the workpiece 1 having only the atmospheric pressure and the lateral pressure transmission cylinder 3, so that the pressure seal member 5 is plastically deformed and accompanied by loud noise. However, it blows off momentarily. Therefore, the prescribed positioning of the hydraulic pressure applying member 8 is as follows.
Since this is an important factor before establishing the optimal cutting conditions, it is necessary to repeat the preliminary experiment sufficiently to calculate the set value.

Specifically, the specified position of the hydraulic pressurizing member 8 has been determined by adjusting the thickness of the spacer 17 from the beginning of the introduction. However, the thickness of the spacer 17 has a minute processing limit, and the minimum thickness of 0.1 mm is required. The only way to find the cutting conditions is to search for the resolution. In addition, the specific adjustment method is to remove the hydraulic pressurizing member 8, attach the spacer 17, check if there is any oil leakage after boosting, and reapply the hydraulic pressure. The operation of removing the pressure member 8 is repeated, that is, only a so-called random adjustment can be performed. Determining the optimum specified position is not reliable in terms of accuracy, and requires much labor and time.

The hydraulic pressurizing member 8 has a stepped outer periphery, is a concentric hollow cylinder machined into a plurality of outer diameters, and has an inner diameter including a clearance into which a desired workpiece can be freely inserted. Finished in condition. When expressed by the pressure on the pressing surface applied when moving to the specified position, the hydraulic pressure applying member 8 needs a pressing force to push back the applied cutting pressure. The value of the pressure applied to the pressing surface can be approximately calculated by (cross-sectional area of first metal member / pressing area of hydraulic pressing member) × (cutting pressure + α).

However, in consideration of the improvement of the durability of the components of the pressure vessel, it is indispensable to set the pressing force as low as possible. However, when the size of the pressure vessel 11 is kept constant, When the outer diameter is larger, the cutting pressure is inevitably higher, and there is a limit due to the limitation of the container size even if an attempt is made to increase the area of the pressing surface, and the hydraulic pressurizing member 8 is securely held during the cutting operation. In order to continue, the pressure applied to the pressing surface of the hydraulic pressure applying member 8 must be increased to cope with it.

When the pressure applied to the pressing surface of the hydraulic pressurizing member 8 is increased in such a use environment, the pressure seal member 5
Unnecessary impact force applied to the side pressure transmission cylinder 3 increases in proportion to it, and when cutting a workpiece with a large outer diameter, there is a problem that the use limit of the pressure vessel constituent members is greatly reduced. Was.

Further, when continuous cutting is performed in a state where the airtightness of the pressure vessel constituent members is reduced, an error may occur outside the set values while the set pressure rising time, the set pressure and the like are repeatedly used. As a result, cutting is performed under inappropriate cutting conditions, and the yield of the optical element material is reduced.

As described above, in order to obtain a predetermined optical element material, it is necessary to search for an optimal cutting condition. To give a concrete example, it is necessary to determine the main conditions such as the load on the side surface of the work, the pressure required for cutting, and the set cutting pressure.However, before determining these conditions, the pressure must be determined. Optimization of the specified position setting of the component members in the container, pitch distance of the streak, adjustment of the work insertion distance, and specified position of the hydraulic pressure member is also indispensable, unless the reproducibility of cutting is confirmed, especially, Even if only the main conditions are optimized, the determined cutting conditions will not make sense.

The present invention has been made in view of the above-mentioned problems of the prior art, and has improved durability of a side pressure transmission cylinder, a pressure seal member, and the like that constitute the inside of a pressure vessel. It is an object of the present invention to provide a side pressure cutting method and a side pressure cutting method capable of obtaining a high-precision high-quality optical element material without loss, miniaturizing a specified position of a hydraulic pressure member, and greatly shortening a cutting condition finding time. .

[0021]

Means for Solving the Problems In order to achieve the above object, an invention according to claim 1 of the present invention is a side pressure cutting method for cutting a workpiece radially by applying a lateral pressure to the workpiece. A plurality of striations are formed on the outer peripheral surface of the workpiece, and the workpiece is inserted into a side pressure transmission cylinder attached to the inside of the pressure vessel, and a pair of pressure seals provided on both sides of the side pressure transmission cylinder A hydraulic pressurizing member for pressurizing and deforming the member is slidably mounted between the retracted position and the prescribed position, detects the position of the hydraulic pressurizing member, and transmits the detected position signal of the hydraulic pressurizing member to the above. The hydraulic pressure applying member at the retracted position is moved to the specified position while controlling the difference between the position command signal and the position command signal to be substantially zero by comparing with a position command signal for setting a specified position. By applying a predetermined lateral pressure to the lateral pressure transmission cylinder. Serial workpiece was cut in a radial direction, the cutting after the hydraulic pressure member, characterized in that so as to move to the retracted position than the predetermined position.

The invention according to claim 2 is characterized in that the specified position is set arbitrarily by making the position command signal variable.

According to a third aspect of the present invention, a lateral pressure applied to the lateral pressure transmission cylinder is detected, and the specified position is adjusted while maintaining a temporal change in the detected lateral pressure at a predetermined value. It is characterized by.

The invention according to a fourth aspect is characterized in that the specified position is swung during cutting of the workpiece.

Further, a fifth aspect of the present invention is a side pressure cutting device for cutting a workpiece in a radial direction by applying a lateral pressure to the workpiece, comprising a pressure vessel, and a plurality of pressure vessels mounted inside the pressure vessel. A side pressure transmitting cylinder into which a workpiece having a streak formed on the outer peripheral surface is inserted, a pair of pressure sealing members abutting on both end faces of the side pressure transmitting cylinder, and a pair of metal members respectively holding the pressure sealing members A hydraulic pressurizing member slidably mounted between the retracted position and the prescribed position inside the pressure vessel and pressurizing and deforming the pressure seal member via the metal member; and Position detecting means for detecting a position, servo valve means for instructing the amount of movement of the hydraulic pressure applying member, a servo control device electrically connected to the position detecting means and the servo valve means, and Connected A pressure generating device for applying a predetermined pressure to the side pressure transmission cylinder and the hydraulic pressure applying member, comparing a position signal detected by the position detecting means with a position command signal for controlling an opening / closing amount of the servo valve means; While moving the hydraulic pressurizing member at the retracted position to the specified position while controlling the servo control device so that the difference becomes substantially zero, a predetermined pressure is applied to the side pressure transmitting cylinder by the pressure generating device. The workpiece is cut in the radial direction by applying a lateral pressure, and after cutting, the hydraulic pressurizing member is moved from the specified position to the retracted position.

According to a sixth aspect of the present invention, the position setting means for setting the prescribed position is electrically connected to the servo valve means and the servo control device, and the position setting means sets the position command signal. And the specified position is set arbitrarily by operating the servo valve means.

According to a seventh aspect of the present invention, a pressure detecting means is mounted between the hydraulic pressure applying member and the servo valve means, and a predetermined pressure lapse based on the pressure detected by the pressure detecting means. The prescribed position is adjusted by the servo valve means while maintaining the change.

According to another aspect of the present invention, a signal generating means is electrically connected to the servo control device, and the specified position is determined based on an output signal from the signal generating means during cutting of a workpiece. It is characterized by swinging.

With the above configuration, the specified position and the moving speed of the hydraulic pressurizing member can be arbitrarily set, and the hydraulic pressurizing member can be smoothly moved to the specified position. For example, it is most suitable for cutting a bar-shaped workpiece. The cutting process can always be reproduced. In particular, durability can be improved while minimizing the deterioration difference of consumable members in the pressure vessel, which is highly dependent on workpieces with various outer diameters, and high quality optical element materials are always obtained. be able to.

[0030]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 shows a side pressure cutting device M1 according to Embodiment 1 of the present invention, which is used for cutting a bar-shaped workpiece 1 made of a brittle material. When cutting the workpiece 1 using the side pressure cutting device M1, prior to cutting, the indenter (not shown) which has been arranged on the cutting position on the outer peripheral surface of the workpiece 1 is used. Streaks 2 for easily inducing cutting are provided on the outer peripheral surface of the cutting position of the object 1. The tip shape of the indenter is polished at the same arbitrary angle from both sides, and the indenter applies an arbitrary load specified from the vertical direction to the work 1
The striations 2 are formed locally at predetermined intervals in the axial direction of the workpiece 1. The streak 2 is a plurality of notches provided in advance on the outer peripheral surface of the workpiece 1 to designate a cut surface, and the streak 2 is formed on the outer peripheral surface of the workpiece 1 in a radial direction, and It is provided locally for each set distance.

As shown in FIG. 1, the side pressure cutting device M1 according to the first embodiment of the present invention includes a pressure vessel 11, a side pressure transmission cylinder 3 mounted inside the pressure vessel 11, and a side pressure transmission cylinder 3. First and second metal members 6, 7 arranged on both sides, and a pair of pressure seals interposed between both end surfaces of the side pressure transmission cylinder 3 and the first and second metal members 6, 7 A member 5 and a hydraulic pressurizing member 8 slidably mounted inside the pressure vessel 11 and pressing the first metal member 6 in the axial direction.
And a pressure generating device 13 connected to the pressure vessel 11 for applying a predetermined pressure to the side pressure transmitting cylinder 3 and the hydraulic pressure applying member 8.

The pressure generating device 13 includes a hydraulic pump 14 and a pressure intensifier 15. The pressure intensifier 15 communicates with the outer peripheral surface of the side pressure transmission cylinder 3 via a pressure increasing line 12a, while the hydraulic pump 14 connects the pressure increasing line 12b. It communicates with the back side of the step portion 8a of the hydraulic pressurizing member 8 through the intermediary portion.

The hydraulic pressurizing member 8 is fitted into the main body of the pressure vessel 11 while being sealed with a plurality of ring-shaped rubbers, and a spacer 17 is provided on an end surface of the pressure vessel 11 on the hydraulic pressurizing member side. At the same time, the hydraulic pressurizing member 8
A stopper 18 facing the spacer 17 is fixed to the opposite side of the step portion 8a.

The above configuration is substantially the same as the configuration of the conventional side pressure cutting device shown in FIG. 8, and the workpiece 1 on which the streak 2 is formed is transferred to the side pressure transmission 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 fitted into concave portions formed in the first and second metal members 6 and 7, respectively, to improve the airtightness of the pressure chamber at the time of pressure increase. Therefore, the hydraulic pressurizing member 8 which has been retracted when the workpiece is inserted is moved by the pressing force of the hydraulic pump 14 toward the first metal member 6 by a certain distance, and each pressure seal member 5 receives a pressing deformation force. Thereby, the airtightness of the pressure chamber is increased.

The pressure seal member 5 is arranged to hermetically seal the pressure for releasing the rod-shaped workpiece 1 in the axial direction and the pressure for releasing in the radial direction. In such a state, the outer peripheral surface of the side pressure transmission cylinder 3 and the inner peripheral part of the pressure vessel 11 in a section sandwiched by the pair of pressure seal members 5 fitted via the first metal member 6 and the second metal member 7. Becomes airtight, and a pressure chamber is formed in the pressure vessel 11. Therefore, the pressure line 12 is connected to the pressure chamber of the pressure vessel 11.
By flowing hydraulic oil from the pressure (oil pressure) generating device 13 through the line a, a uniform and high lateral pressure can be applied to the outer peripheral surface of the workpiece 1.

The hydraulic pump 14 constituting the pressure generating device 13 for applying the lateral pressure moves and holds the hydraulic pressurizing member 8 in the pressure vessel 11 by the circulating pressure. It has a function as a device. However, the circulating pressure of the hydraulic pump 14 does not directly become the moving pressure, but is connected to a pressure adjusting valve (not shown) during this time, so that the circulating pressure is roughly adjusted and the indicated detection position is maintained as necessary. It supplies pressure. The actual operation of the hydraulic pressurizing member 8 is as follows: the circulating pressures of the two systems 12a and 12b are extracted from the hydraulic pump 14, and one of the systems 12b is used for moving the discharge side, while the other system 12b is used.
a is used for supply side movement.

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. Workpiece 1 has a Young's modulus of 8.2 × 10 ³ kgf / m
A solid cylindrical optical glass rod having an m ² diameter of about 11 mm and used for molding a lens was used. Work 1
A streak 2 for designating a cut surface was stamped with an indenter (not shown). A load of 1000 g or less was applied to the used workpiece 1 at an equal interval of 3 mm in the axial direction on the outer peripheral surface to form eight streaks 2 at eight locations. The length of the streak 2 was 400 μm, and all had the same shape.

As shown in FIG. 1, the workpiece 1 on which the streaks 2 were formed was fitted into a hollow cylinder-shaped side pressure transmission cylinder 3 made of methacrylic resin. Workpiece 1 and side pressure transmission cylinder 3
A known high-viscosity oil / fat was used as the pressure medium 4 enclosed between them. The Young's modulus of the methacrylic resin that is the material of the side pressure transmission cylinder 3 is 3.1 kgf / mm ² . The length of the side pressure transmission cylinder 3 is approximately
The first metal member 6 and the second metal member 7 are made of a ring-shaped rubber having a wire diameter of 1.2 mm.
At predetermined positions.

The material of the first metal member 6 and the second metal member 7 was carbon tool steel. The clearance accuracy of the inner diameter between the workpiece 1 and the first metal member 6 or the second metal member 7 was finished so as to be substantially the same as the clearance accuracy of the side pressure transmission cylinder 3.

As shown in the time-dependent change of the pressure in FIG.
The hydraulic pressure member 8 is provided with a circulating pressure received from the hydraulic pump 14.
The operating oil pressure was applied at 1.2 kgf / mm ² , and instantaneously moved by the gap between the stopper 18 and the spacer 17. The mechanism for setting the movement amount is a method of inserting a spacer 17 having a thickness of about 10 mm and considering surface roughness, and the movement amount is about 1 mm.

Further, the lateral pressure cutting device having the above configuration 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 the pressure was repeatedly increased and reduced. The first time is 198 times, the second time is 210 times, and the third time is 162 times, so that the airtightness of the pressure chamber cannot be maintained, or it becomes impossible to cut a specified number of optical element materials. Even so, the surface quality of the cut surface gradually decreased.

When the pressure vessel 11 was disassembled and examined in the state where the airtightness could not be maintained as described above, a large crack was found in the observed pressure seal member 5 at the portion in contact with the side pressure cutting cylinder 3. As a result, the outer peripheral portion was rubbed and worn over the entire circumference.

Therefore, in the lateral pressure cutting device M1 according to the first embodiment of the present invention shown in FIG. 1, the servo valve 9 for instructing the moving amount of the hydraulic pressure applying member 8 is connected to the boost line 1
2b, a position detector 10 for detecting the position of the hydraulic pressurizing member 8 is mounted on the outer surface of the pressure vessel 11, and the tip of the detection unit of the position detector 10 is
Fixed to Further, while the position signal output from the position detector 10 is input to the servo controller 16,
The servo valve 9 is controlled by the servo controller 16 based on the input position signal.

In the above configuration, the stopper 18 attached to the hydraulic pressurizing member 8 is for determining the entire moving amount of the hydraulic pressurizing member 8, and the position detector 10 fixed on the outer surface of the pressure vessel 11 is used. The tip of the detection unit is set to the hydraulic pressure member 8
It is possible to grasp the axial movement amount of the hydraulic pressurizing member 8 with a resolution of 0.01 mm by being fixed to a part of.

In the first embodiment, the hydraulic pressure member 8
The total travel distance from the evacuation position to the specified position was set to 1 mm. The current position signal detected by the position detector 10 is compared with a position command signal for controlling the opening / closing amount of the servo valve 9, and the servo control device 16 controls the difference so that the difference becomes substantially zero. The circulation pressure of the hydraulic pump 14 is 1.2 kgf as described above.
It was set in / mm ^2.

FIG. 2 shows the change over time of the pressure indicating the operation of the hydraulic pressure applying member 8. The actual operation was as follows: before the cutting pressure was generated after the workpiece 1 was inserted, the hydraulic pressurizing member 8 was moved from the retreat position to the specified position at a constant pressure for about 5 seconds at a slow speed of about 0.2 mm / s. After the hydraulic pressurizing member 8 is set at the specified position, the pressurization is started, and after the cutting operation with the side pressure of 8.5 kgf / mm ² , the pressurizing time of 5 seconds, and the set holding time of 3 seconds, the hydraulic pressurizing member 8 is retracted from the specified position. It was moved to the position in about one second. The result of the limit use number of continuous cutting in a series of operations is the first 310 times, the second time 3
The number of times of use was improved to 00 times and 3 times to 299 times, and the optical element material obtained by this cutting method was at a level having no problem in quality. Further, in the appearance of the pressure seal member 5 which can be used when used 300 times in the continuous cutting, it was not possible to visually confirm such a large abrasion or crack. However, when comparing the conventional example shown in FIG. 9 with the case of using the first embodiment of FIG. 2, the first embodiment requires more time because of the difference in the moving time of the hydraulic pressure member 8. When compared as a total tact (cycle time) from pressure increase to pressure reduction, the difference is very small. Stopper 1
8 does not need to have a high thickness accuracy.

FIG. 3 shows a processing process of the optical element 22 formed by performing post-processing, ie, heating, pressurizing, and cooling, on the optical element material obtained by the lateral pressure cutting in the first embodiment. Is shown.

The optical element 22 is used as one of the lenses for a video movie, and although not shown in detail, one side is an aspherical surface and the opposite surface is a spherically convex surface having a spherical surface. Further, the transfer surfaces of the first molding die 20 and the second molding die 21 used in the molding are each processed into a desired concave shape, and are fitted into the upper and lower inner diameter portions of the body die, respectively. The transfer accuracy of the optical element 22 obtained through the molding process was not different from that obtained when an optical element material of another shape was molded, and was a performance having no problem in optical characteristics.

In the first embodiment, it is possible to appropriately select and set the value of the lateral pressure, the boosting time, or the retaining time for the lateral pressure in response to the change of the object to be processed. Further, the moving speed of the hydraulic pressurizing member 8 to the specified position is set to 0.2 mm / s, but it is not necessary to limit to this moving speed. Further, as for the servo valve 9, the servo control device 16, the position detector 10, and the like, other similar means can be adopted as long as they have the above-described functions.

As described above, according to the lateral pressure cutting method of the first embodiment, unnecessary impacts applied to the pressure sealing member 5 by the hydraulic pressure applying member 8 are eliminated, and the spacer 17 having high thickness accuracy is provided.
And the effect of minimizing deterioration of the pressure seal member 5 can be obtained.

(Embodiment 2) FIG. 4 shows a lateral pressure cutting device M2 according to Embodiment 2 of the present invention. In addition,
Members corresponding to those described with reference to FIGS. 1 and 3 are denoted by the same reference numerals, and detailed description is omitted. The configuration of the side pressure cutting device M2 is the same as that of the side pressure cutting device M1 according to the first embodiment.
The configuration is basically the same as that of FIG.
The difference is that means for arbitrarily setting and holding the specified position of the hydraulic pressure applying member 8 is arranged between the output of the servo controller 16 and the output of the servo controller 16. As the position setting holding means, for example, a position adjusting variable resistor 23 is used.

Hereinafter, specific conditions in the side pressure cutting performed by using the side pressure cutting device M2 will be described. The workpiece 1 used for the study has a Young's modulus of 1.03 × 10 ⁴ kgf / mm ² and an outer diameter of about 7 m
m is a solid cylindrical optical glass rod, which has been finished to the same shape accuracy as that used in Embodiment 1, and further has a striation 2 provided on the outer peripheral surface of the workpiece 1 with a load of 900 g; Although the pitch distance is 4.5 mm, which is different from the above setting, the pitch distance is almost the same.

As described in the first embodiment, when determining the specified position of the hydraulic pressurizing member 8 which is considered to be optimal at present, the moving amount of the hydraulic pressurizing member 8 is changed by the spacers 17 having different thicknesses by 0.1 mm. Approximately six hours were required to prepare dozens of types and determine the optimal airtightness.

Therefore, the circulating pressure of the hydraulic pressure applying member 8 is set to 1.8 kgf / m by using the position detector 10, the servo valve 9, the servo control device 16, and the variable resistor 23 for position adjustment.
m ² and the optimal specified position was determined. As a result, it was found that the allowable amount of the specified position at which good airtightness was obtained was 0.05 mm, judging from the quality of the optical element material. Further, since the actual optimum specified position range can be easily set with an accuracy of 0.01 mm while adjusting the position adjustment variable resistor 23, it can be derived in about one hour.

Since the position adjusting variable resistor 23 can change the position command signal in the servo controller 16, when the servo controller 16 manually adjusts the specified position of the hydraulic pressurizing member 8, the position command signal is changed. If it is variable, the current position signal also changes at the same rate of movement so as to follow it, so that the hydraulic pressure applying member 8 can be easily set to an arbitrary position.

Although the position adjusting variable resistor 23 is used as the position setting holding means in the second embodiment, any other means having a function of moving the hydraulic pressurizing member 8 to an arbitrary position can be used. Alternatively, there is no problem even if an element is used. In addition to the analog operation using the position adjustment variable resistor 23, the automatic operation can be performed with a simple sequence program by adding a function of digitally changing the voltage.

As described above, according to the lateral pressure cutting method of the second embodiment, the optimum specified position of the hydraulic pressure applying member 8 can be obtained in a relatively short time without bothering the user, and the airtightness of the pressure chamber is improved. Therefore, when mass-producing other types of optical element materials or searching for each cutting condition, time loss can be minimized.

(Embodiment 3) FIG. 5 shows a lateral pressure cutting device M3 according to Embodiment 3 of the present invention. In addition,
Members corresponding to those described with reference to FIGS. 1 to 3 are denoted by the same reference numerals, and detailed description is omitted. The configuration of the side pressure cutting device M3 is the same as that of the side pressure cutting device M1 according to the first embodiment.
The pressure gauge 24 is arranged at an arbitrary position in the booster line 12a between the pressure intensifier 15 and the pressure vessel 11, and the voltage change of the pressure gauge 24 is connected to the connected pressure indicator 25. Differs in that they are simply displayed. The pressure indicator 25 is connected to an input terminal of the servo control device 16, and the set pressure value fluctuation during the pressure increase is controlled by the servo control device 16.
Can be monitored constantly.

Hereinafter, specific conditions in the side pressure cutting performed using the side pressure cutting device M3 will be described. The workpiece 1 used for the study has a Young's modulus of 1.03 × 10 ⁴ kgf / mm ² and an outer diameter of about 7 m
m is a solid cylindrical optical glass rod, finished with the same shape accuracy as that used in the second embodiment, and the striations 2 are almost the same shape with a load of 900 g and a pitch distance of about 4.5 mm. It is.

The specified position of the hydraulic pressurizing member 8 has already been determined at a position where optimum airtightness can be maintained. In this state, continuous cutting was performed. As a result, the limit number of uses of the pressure vessel constituent members was 314, and when the number of defects was analyzed by the number of uses from the quality yield of the optical element material, the number of defects of 1 to 50 times of use was 23, 51 to 100.
23 times, 1 for 101-150 times, 3 for 151-200 times
The results were 4 for 201 to 250 times and 8 for 251 to 300 times. From these results, when the initial number is from 1 to 100 times, the number of defects occurs most, the number of defects decreases drastically during the medium number of 101 to 200 times, and the number of defects at the late number of times after 201 Was found to tend to increase gradually.

Therefore, the pressure gauge 24 and the pressure indicator 25
The change amount obtained by the voltage conversion is input to the servo controller 16 to constantly monitor the change over time of the cutting pressure, and a function of finely adjusting the position of the hydraulic pressure applying member 8 according to the minute change amount is introduced.

When the position of the hydraulic pressurizing member 8 is changed during the pressurization, the volume of the pressure chamber changes, so that the cutting pressure also changes. In the pressure increasing process, the hydraulic pressure applying member 8 is moved from the reference position to 0.
It has been confirmed in advance that when moved by 1 mm, it changes about 2.5% with respect to the cutting pressure. Since the cutting pressure set in the third embodiment is 8.0 kgf / mm ² , for example, when the hydraulic pressure member is moved ± 0.1 mm while maintaining the set pressure, the cutting pressure is ±
0.2 kgf / mm ² will vary.

The circulating pressure of the hydraulic pressurizing member 8 must be increased to 2.0 kgf / mm ² compared with the conventional setting condition and pushed back from the cutting pressure because the hydraulic pressurizing member 8 needs to be moved during the pressure increase. It was used at such a pressure as not to be affected.

Further, when the output signal of the pressure indicator 25 is taken in and analyzed in detail using an analog monitor (not shown), the change over time of the cutting pressure in the initial, middle and late stages of the number of times of use is particularly found. Was found to decrease gradually.

From the above examination results, when the number of times the pressure vessel constituent members were used in the middle period, the quality yield of the optical element material was good, so the typical boosting behavior at that time was analyzed in detail and managed as a master waveform. Meanwhile, the servo control device 16 was used to adjust the opening and closing of the servo valve 9 so as to obtain a pressure rising pattern close to the master waveform by comparing the pressure reading with the pressure gauge 24 in the pressure rising behavior for each number of times.

As a result, the variation in the quality yield due to the number of times of use as before was reduced, and the number of defects was evaluated every 50 times of continuous use as described above. The weight dispersion of each optical element material was about 20 minutes. A result that falls within about 1 was obtained.

The third embodiment is not limited to a series of mechanisms as long as it has a function of measuring the amount of change in pressure. Further, the shorter the reaction time of the change in the pressure behavior and the servo valve control corresponding thereto, the quicker the waveform approximate to the master waveform is formed.

(Fourth Embodiment) FIG. 6 shows a lateral pressure cutting device M4 according to a fourth embodiment of the present invention.
FIG. 9 is a schematic diagram showing a change over time in pressure according to the fourth embodiment. Members corresponding to the members described with reference to FIGS. 1 to 3 are denoted by the same reference numerals, and detailed description is omitted. The configuration of the side pressure cutting device M4 is basically the same as the configuration of the side pressure cutting device M1 according to the first embodiment, except that a signal generator 26 serving as a signal generating unit is arranged in the servo control device 16 only. .

Hereinafter, specific conditions in the side pressure cutting performed by using the side pressure cutting device M4 will be described. The workpiece 1 used for the study has a Young's modulus of 1.03 × 10 ⁴ kgf / mm ² and an outer diameter of about 7 m
m is a solid cylindrical optical glass rod according to Embodiment 2,
3 is finished to the same shape accuracy as that used in Example 3, and the striations 2 are almost the same shape with a load of 900 g and a pitch distance of about 4.5 mm.

The specified position of the hydraulic pressurizing member 8 has already been determined at a position where optimum airtightness can be maintained. The circulating pressure of the hydraulic pump 14 is the same as that of the third embodiment.
It was set to 2.0 kgf / mm ² , the same as above.

In this state, the cutting pressure is 8.0 kgf / m
The cutting conditions were set to m ² , a boosting time of 5 seconds, and a holding time of 3 seconds, and the continuous cutting was performed. The limit number of uses was 314 times. A defective optical element material with cuts or cracks was generated. As a result of evaluating the appearance of the pressure seal member 5,
Cracks were partially generated on the contact surface with the side pressure transmitting cylinder 3 and the contact portion with the pressure vessel 11 was deteriorated to be worn over the entire circumference.

Therefore, the signal generator 26 controls the hydraulic pressurizing member 8
A function to swing the specified position has been incorporated. Signal generator 2
The operation of No. 6 is to output a voltage signal that repeats at a constant amplitude to the servo valve 9. Such a signal generator 2
By receiving the operation of 6, within the cutting pressure holding time,
The waveform of the signal generator 26 is superimposed, and the hydraulic pressure applying member 8 adjusts the circulating pressure value based on the optimal specified position.
The pressure changes in the same cycle as 6. Also, the cutting pressure value is 8.0k
In the case of gf / mm ² , it fluctuated with an amplitude of about ± 0.1 mm, and the pressure fluctuation at that time was ± 0.1 kgf / mm ² . When the cutting was verified under such setting conditions, all the pieces were cut to the specified number of cuts, but during continuous cutting, more than the specified number was cut, or cracks frequently occurred within the specified distance per piece. Since it occurred, the cutting pressure was reduced to 7.2 kgf / mm ² and the verification was performed again. As a result, almost no abnormal cutting as occurred at 8.0 kgf / mm ² was observed. In addition, the maximum number of uses of the pressure vessel components can be up to 439,
The surface quality of the obtained optical element material 19 was also at a level with almost no problem.

In the fourth embodiment, as the waveform signal of the signal generator 26, any periodic signal represented by a sine wave, a rectangular wave, or a triangular wave is effective.
It is also possible to use various format settings such as their amplitude and period.

As described above, according to the lateral pressure cutting method of the fourth embodiment, by oscillating the hydraulic pressurizing member 8, the optimum cutting pressure condition is always reproduced without fluctuating according to the number of times of use. Since the required pressure is set lower than in the conventional method, and the consumption of the pressure vessel constituent members can be suppressed as much as possible, the number of continuous cutting operations that can be used can be improved.

[0075]

Since the present invention is configured as described above, it has the following effects. Cutting does not involve cutting chips or noise, does not require more time and energy, requires only a single application of lateral pressure to ensure that multiple specified cuts are made, and that the pressure chamber is airtight. By considering the durability of the pressure vessel constituent member, which is indispensable for maintaining the performance, it is possible to improve the limit number of use times of the pressure vessel constituent member.

Further, for example, when used for continuous cutting of optical element materials, high-quality and high-quality materials can always be stably obtained, the number of maintenance operations of the pressure vessel is reduced, and the cost of mass production is reduced. , Yield improvement and rationalization can be achieved.

In particular, claim 1 or claim 5 of the present invention
According to the invention described in the above, the position of the hydraulic pressurizing member is detected,
The detected position signal of the hydraulic pressurizing member is compared with a position command signal for setting a specified position, and while controlling the difference between the position signal and the position command signal to be substantially zero, the hydraulic pressurizing member at the retracted position is controlled. Since the member was moved to the specified position,
The impact force generated when the hydraulic pressurizing member is moved can be suppressed as much as possible, and the deterioration of the side pressure transmission cylinder and the pressure seal member which have occurred so far can be suppressed as the number of times of use increases.

Further, since the hydraulic pressurizing member is forcibly moved to the retracted position after the end of the cutting, the time required for the pressure seal member to return to the original shape is shortened, and the total tact from pressurization to decompression is reduced. The pressure can be shortened and the pressure can be released smoothly.

According to the second or sixth aspect of the present invention, the specified position is arbitrarily set by making the position command signal variable, so that unnecessary external force is applied to the hydraulic pressure applying member. In addition, the service life of the side pressure transmission cylinder and the pressure seal member can be extended, and the cutting condition most suitable for the bar-shaped workpiece can be determined in a relatively short time.

According to the third or seventh aspect of the present invention, the predetermined position is adjusted while detecting the lateral pressure applied to the lateral pressure transmission cylinder and maintaining the detected temporal change of the lateral pressure at a predetermined value. Therefore, the cutting pressure can be finely adjusted in response to a sudden change in the set pressure, and the cutting pressure can be maintained at a constant value. Therefore, it is possible to continuously maintain the optimum cutting conditions according to the use condition of the pressure seal member and the side pressure transmission cylinder.

According to the invention as set forth in claim 4 or 8, since the specified position is swung while the workpiece is being cut, and hence while the set pressure is being held, the specified number of cuts can be performed at one time. The set pressure can be set lower than the required original cutting pressure.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a lateral pressure cutting device according to a first embodiment of the present invention.

FIG. 2 is a graph showing a change with time in pressure when a workpiece is cut using the side pressure cutting device of FIG. 1;

FIG. 3 is a cross-sectional view showing a process of manufacturing an optical element by using an optical element material obtained by the side pressure cutting of the side pressure cutting apparatus of FIG. 1;

FIG. 4 is an overall configuration diagram of a lateral pressure cutting device according to a second embodiment of the present invention.

FIG. 5 is an overall configuration diagram of a lateral pressure cutting device according to a third embodiment of the present invention.

FIG. 6 is an overall configuration diagram of a lateral pressure cutting device according to a fourth embodiment of the present invention.

FIG. 7 is a graph showing a change with time in pressure when a workpiece is cut using the lateral pressure cutting device of FIG. 6;

FIG. 8 is an overall configuration diagram of a conventional side pressure cutting device.

9 is a graph showing a change over time in pressure when a workpiece is cut using the lateral pressure cutting device of FIG. 8;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Workpiece 2 Mark 3 Side pressure transmission cylinder 4 Pressure medium 5 Pressure seal member 6 First metal member 7 Second metal member 8 Hydraulic pressurizing member 9 Servo valve 10 Position detecting means 11 Pressure vessels 12a, 12b Boosting line 13 Pressure generating device 14 Hydraulic pump 15 Intensifier 16 Servo control device 17 Spacer 18 Stopper 19 Optical element material 23 Variable resistor for position adjustment 24 Pressure gauge 26 Signal generator

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hiroyuki Mukai 1-1-1, Fujikoshi Honcho, Toyama City, Toyama Prefecture F-term Co., Ltd. F-term (reference) 3C060 CD00 CD02 3C069 AA01 BA07 BB01 CA11 4G015 FA01 FB03 FC11 FC14

Claims (8)

[Claims] 1. A lateral pressure cutting method for cutting a workpiece in a radial direction by applying a lateral pressure to the workpiece, wherein a plurality of striations are formed on an outer peripheral surface of the workpiece, and the workpiece is placed inside a pressure vessel. A hydraulic pressure member that is inserted into the attached side pressure transmission cylinder and pressurizes and deforms a pair of pressure seal members provided on both sides of the side pressure transmission cylinder is slidably mounted between the retracted position and the prescribed position, The position of the hydraulic pressurizing member is detected, and the detected position signal of the hydraulic pressurizing member is compared with a position command signal for setting the specified position, and a difference between the position signal and the position command signal is substantially zero. While controlling so that the hydraulic pressure applying member at the retracted position is moved to the specified position, the workpiece is radially cut by applying a predetermined side pressure to the side pressure transmitting cylinder, and after the cutting, Move the hydraulic pressure member to the retracted position from the specified position. Lateral pressure cutting method, characterized in that so as to move up. 2. The lateral pressure cutting method according to claim 1, wherein the specified position is arbitrarily set by making the position command signal variable. 3. The lateral pressure cutting method according to claim 1, wherein the lateral pressure applied to the lateral pressure transmission cylinder is detected, and the specified position is adjusted while maintaining a temporal change of the detected lateral pressure at a predetermined value. 4. The lateral pressure cutting method according to claim 1, wherein the specified position is swung during cutting of the workpiece. 5. A side pressure cutting device for applying a side pressure to a workpiece to cut the workpiece in a radial direction, comprising: a pressure vessel; and a plurality of striations formed on an outer peripheral surface of the pressure vessel. Side pressure transmitting cylinder into which the work having been inserted is inserted, a pair of pressure seal members abutting on both end faces of the side pressure transmission cylinder, a pair of metal members respectively holding the pressure seal members, and retracted inside the pressure vessel. A hydraulic pressurizing member slidably mounted between a position and a prescribed position and pressurizing and deforming the pressure seal member via the metal member; and a position detecting means for detecting a position of the hydraulic pressurizing member; Servo valve means for instructing the amount of movement of the hydraulic pressurizing member; a servo control device electrically connected to the position detecting means and the servo valve means; and a side pressure transmitting cylinder and the hydraulic pressure connected to the pressure vessel Addition A pressure generating device for applying a predetermined pressure to the member, and comparing the position signal detected by the position detecting means with a position command signal for controlling the opening / closing amount of the servo valve means, so that the difference becomes substantially zero. After moving the hydraulic pressurizing member at the retracted position to the specified position while controlling by the servo control device, a predetermined side pressure is applied to the side pressure transmission cylinder by the pressure generating device to thereby cause the workpiece to have a diameter. Wherein the hydraulic pressurizing member is moved from the specified position to the retracted position after the cutting. 6. The servo valve means and the servo control device are electrically connected to position setting means for setting the specified position, and the position command signal is made variable by the position setting means to operate the servo valve means. The side pressure cutting device according to claim 5, wherein the specified position is set arbitrarily by causing the predetermined position to be set. 7. A pressure detecting means is provided between the hydraulic pressure applying member and the servo valve means, and the predetermined position is maintained while maintaining a predetermined change with time based on the pressure detected by the pressure detecting means. 6. The side pressure cutting device according to claim 5, wherein the adjustment is performed by the servo valve means. 8. The servo control device according to claim 5, wherein a signal generating means is electrically connected to the servo control device, and the specified position is swung based on an output signal from the signal generating means while the workpiece is being cut. 3. The side pressure cutting device according to claim 1.