JPH0777966B2 - Method and apparatus for cutting quartz glass rod - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention automatically adjusts a stretched glass rod to a predetermined length in a process of stretching a quartz glass rod (hereinafter, simply referred to as “glass rod”). The present invention relates to a cutting method and a cutting device for cutting, which prevents a defective shape of a cutting portion of a glass rod and enables the cutting device to be compact and incorporated into a glass rod drawing device.

[Prior Art] In the process of stretching a quartz glass rod, when a glass rod stretched to a diameter of about 20 mm reaches a predetermined length, the glass rod is cut to produce a glass rod of a predetermined length, which is the following conventional method. Was adopted.

(A) A part of the outer periphery of the glass rod is scratched to form a fractured part, and then the glass rod is bent laterally to fracture at the fractured part.

(B) A part of the outer periphery of the glass rod is scratched to form a fractured portion, and then the glass rod is fractured at the fractured portion by applying a lateral impact force such as bending.

(C) The entire circumference of the glass rod is scratched (A) and broken in the same manner as (B).

(D) A disk-shaped grindstone is rotated at a high speed and cut by cutting.

(E) Gas is cut by a gas burner.

When the above methods (d) and (e) are adopted, the cutting device therefor becomes complicated and large-scale. Further, when adopting the above methods (a) and (b), the apparatus is simple, but a wide working space is required for work such as bending the glass rod or applying an impact force. Regarding method (c), it takes time to scratch the entire circumference, and the device becomes complicated.

The present invention is based on (a) and (b) of the above-mentioned conventional techniques. In this premised technique, a part of the outer peripheral surface of the glass rod is scratched to form a fractured part, and a bending moment is applied to this fractured part, or a transverse impact is applied to break the fractured surface. The shape of is likely to be defective, and the cross section may be an oblique direction with respect to the center line of the glass rod. The end of the glass rod is cut off again in order to make the end face of the glass rod a plane perpendicular to the center line, but at this time, the cut-off portion is not small, and the material is wasted, and this material is wasted. It is required to reduce the yield and improve the yield.

Further, when an external force in the horizontal direction is applied to the hanging glass rod by the cutter, the upper end of the glass rod cut by this external force is swayed and cannot fall vertically. On the other hand, depending on the glass rod, there is a demand to avoid scratching the surface of the glass rod as much as possible. For this reason, the glass rod that is cut and dropped must be received vertically by a special receiving device and stored vertically in the receiving device.

However, when the cut glass rod has its upper end swayed by the cutting force, the glass rod moves laterally and falls into the receiver, and its movement is not constant. For this reason, there are many cases where a part of the cut glass rod comes into contact with the receiving member and the surface thereof is slightly scratched.

[Problems to be solved by the invention]

The present invention, for a cutting method for cutting a quartz glass rod by breaking, aims to solve the above-mentioned various problems, for that, it is possible to perform the cutting work by applying impact force (cutting time No need), the fracture surface should be as smooth as possible at right angles to the center of the glass rod, the cutting device should not be bulky, and To prevent lateral force from being applied due to cutting force, the above 4
The problem is to solve one problem at a time.

[Means taken to solve the problem] The means of the present invention taken to solve the above problems are constituted by the following elements (a) to (c).

(A) Drive a pair of left and right cutters symmetrically around the suspended quartz glass rod, (b) Synchronize the left and right cutters simultaneously and make them collide with the glass rod from the opposite side, (c) Left and right Using the cutter of (1), make notches at the same time on the opposite surfaces in the same horizontal plane of the outer circumference of the glass rod and apply impact force in opposite directions.

[Operation] The left and right cutters cut the surface of the glass rod opposite to the outer periphery of the glass rod with impact, so that the glass rod is broken at the fracture surface along the cut. At this time, the impact forces applied to the glass rod by the left and right cutters are at the same time and in opposite directions, and are equal to each other, and therefore cancel each other out at the center of the glass rod.
Therefore, the lateral force acting on the glass rod by the cutting force of the cutter is zero in total. In other words,
Since the cutting forces act on the hanging glass rod from opposite directions within the same water surface, the moment due to the left and right cutting forces (the force to rotate the glass rod in the vertical plane) is zero, and The forces from are equal and are in opposite directions, so their sum is zero, and thus the force pushing the cut laterally is zero in total. Therefore, the cut glass rod does not move laterally, and drops vertically as it is hung. Also,
Since the above-mentioned cuts by the left and right cutters are simultaneously made in a plane perpendicular to the center line of the glass rod, the fracture surface becomes a smooth flat surface (a stepped or non-diagonal flat surface) conforming to the cut.

As a driving device for carrying out the above cutting method, a coil spring, a force accumulating means such as air pressure, and a force accumulating means such as a motor, an electromagnet, a pneumatic device, etc., are accumulated in an instant. And a driving mechanism for synchronously driving the left and right cutters toward the glass rod at high speed. In practice, these mechanisms can be made extremely simple and compact.

[Embodiment] A first embodiment of the present invention will be described with reference to FIGS. 1 and 2.

Plunger 3 slidably in guide hole 2 of housing 1
The plunger 3 is urged in one direction by the force accumulation spring 4. Blades 7'are attached to a pair of left and right L-shaped links 6 pivotally supported by a pin 5 on the housing 1.
The attached cutter 7 is fixed. The cutters 7, 7 are arranged symmetrically with respect to the quartz glass rod 8.

Both sides of the plunger 3 are sandwiched by the arms 9 and 9 of the L-shaped links 6 and 6, and the slots 1 of the arms 9 and 9 are
Pin 11 is fitted to 0 and 10. The pins 11 are pins provided on both sides of the plunger 3.

An electric motor M is fixed to the housing 1, and a spiral cam 13 is attached to a shaft 12 of the electric motor M. The cam surface 14 of the spiral cam 13 is a 360-degree spiral cam surface 14, and a start point S and an end point E thereof are joined by a radial step surface 15.

When the motor M rotates, the spirally wound cam 13 rotates in the clockwise direction to push out the plunger 3 while compressing the accumulating spring 4. When the spiral cam 13 rotates 360 degrees, the sliding stroke of the plunger 3 reaches the maximum stroke, and the cam follower 3 ′ is disengaged from the end point E of the cam surface 14. At this time, the plunger 3 is strongly pushed back at high speed by the accumulating spring 4, and the pin 11 causes the L-shaped links 6 and 6 to rotate about the pins 5 and 5 in directions opposite to each other (direction toward the glass rod). . Therefore, the cutters 7, 7 rotate in the direction of arrow F, and the blades 7 ′, 7 ′ collide with the quartz glass rod 8. The blades 7 ′, 7 ′ make cuts on the surfaces of the quartz glass rod 8 on the opposite sides of the outer circumference, and at the same time, the glass rod 8 is broken by hitting with equal force from the opposite sides.
The motor M stops when it rotates 360 degrees.

Next, a second embodiment will be described with reference to FIG. This embodiment is an embodiment in which the biasing means including the electric motor M, the spiral cam 13 and the cam follower 3'of the first embodiment is replaced with an electromagnet.

The L-shaped link 6 is pivotally supported by the pin 25 on the casing 21 of the electromagnet, and the pins 31, 31 of the electromagnetic plunger 33 are fitted in the slots 30, 30 of the arms 29, 29 of the L-shaped link 6.

The plunger 33 is slidably guided by a non-magnetic guide sleeve 32, and is pushed in one direction by a force accumulation spring 34.

The electromagnetic coil 35 is fitted in the yoke 36, and the yoke 36 is fixed to the housing 21. The plunger 33 reciprocates between the fixed iron core 37 and one end of the yoke 36.

When the electromagnetic coil 35 is energized, the plunger 33 causes the spring 34 to accumulate.
Is extruded while compressing. If a timer circuit is incorporated in the control circuit of the electromagnet and the power supply to the electromagnetic coil 35 is automatically cut off after a predetermined time (about 1 second), the plunger 31
Is strongly and rapidly pushed back by the storage spring 34. At this time, the left and right L-shaped links 6, 6 rotate about the pins 25, 25 in opposite directions.

The structure of the electromagnet may be any structure as long as the plunger is pushed out when energized.However, when adopting the structure shown in the figure, the head 33 'of the plunger 33 is made a strong permanent magnet and it is energized. The plunger may be pushed out by the repulsive force of the magnetic flux of the fixed iron core 37. Further, the driving force of the electromagnet may be applied in the glass rod cutting direction.

Other examples include the following.

The driving means such as an electric motor and an electromagnet is replaced with a driving means by fluid pressure such as air pressure or hydraulic pressure, and the plunger is directly or indirectly stroked against the accumulating spring by fluid pressure.
In the accumulated state, the plunger is locked by the trigger, this trigger is controlled by an electromagnet, etc.
The energy stored in the spring is released instantly.

The blade of the cutter is carbon steel (S45C) quenched.

[Effect] The invention which solves the above-mentioned problems of the present invention is not known. Therefore, the above four problems are to be able to perform the cutting work by applying impact force (the cutting does not take time), and the fracture surface should be as smooth as possible at right angles to the center of the glass rod. Four problems of ensuring a smooth fracture surface, keeping the cutting device bulky, and preventing the cutting force from exerting a lateral external force due to the cutting force on the glass rod cut. The fact that all the points are solved at once is the effect peculiar to the present invention.

Accordingly, the present invention, when applied to the cutting work of a glass rod which is a base material for optical fiber spinning, improves the efficiency of the work and makes the fracture surface of the glass rod a smooth surface perpendicular to the center line of the glass rod. Therefore, the waste of the material due to the defective shape of the cut surface can be eliminated as much as possible. Also,
The cutting device is made compact and the working space is reduced.
As a result, the cutting device can be incorporated in the stretching device for the glass rod that is the base material for optical fiber spinning, and the stretching device can be made compact.

Further, since the cut glass rod can be dropped vertically below, the cut glass rod can be reliably dropped vertically to the receiving member therebelow, which allows the falling glass rod to fall. It is possible to reduce scratches on the surface of the rod when the rod is housed in the holder.

Incidentally, as a cutting device for a glass rod mainly used for manufacturing a glass lens, a device described in JP-A-59-203735 is known. This is a glass rod, which is the material of the lens, etc.
It cuts automatically, and one fixed position cutter (fixed blade) and the other movable cutter are placed on the opposite side with the glass rod as the center, and the movable cutter is directed toward the fixed position cutter. By moving and moving the glass rod that passes between the cutters from both sides, cuts are made by both cutters in an instant. Although it is mainly intended for cutting glass rods, which are the material of lenses, it is also applied to cutting pipe-shaped glass rods, cutting resin, etc. Since it is stated in the same publication that a fixed position cutter is not necessary and that a flat surface for receiving the glass rod may be used instead, this device is a cutting device mainly for push-cutting similar to so-called cutting scissors. If the object to be cut has a large diameter, it will be difficult to cut with only a moving cutter, so it is considered that a cut is made from the opposite side by a fixed position cutter. Further, it is described in the same publication that it is desirable to vertically shift the fixed position cutter and the movable cutter by about 0.2 mm. Therefore, for one fixed position cutter, the other moving cutter is 0.2m up and down.
They move in planes offset by m, so that the opposing cuts are offset from each other. Therefore, it cannot be expected that the fracture surface will be a smooth flat surface. Furthermore, since the glass rod is pushed toward the fixed position cutter by the moving cutter and pressed against it, the cut glass rod is moved laterally by the cutting force, and the left and right cutters move up and down. Since it is shifted to, it receives a strong momentum due to the cutting force of both cutters and is tilted in the vertical plane, so it is not possible to drop the cut glass rod vertically in a hanging state.

Furthermore, this is considered to be a lens that is cut by cutting a glass rod that has been cut, and polishing this to finish the lens.Therefore, it is necessary to consider the smoothness of the cut surface and the prevention of scratches on the surface of the glass rod. It is considered that the ones that do not exist are targeted for cutting. Therefore, there is no problem even if the fixed cutter (fixed blade) comes into contact with and scratches the surface of the glass rod that droops and runs downward, and the fixed position cutter (fixed blade) is largely separated from the glass rod. Then, it is considered that there is no problem even if the glass rod is laterally moved by the moving cutter and pressed against the fixed position cutter to cut.

Further, since the cutter has a built-in cutter in the rotary disk and the cutting length is measured by the rotation angle of the rotary disk, it is inevitable that the cutting device becomes large.

Therefore, it cannot be denied that this has solved the problem that the cutting work can be performed by applying an impact force among the four problems solved by the present invention (the cutting does not take time). Make the fracture surface as smooth as possible at right angles to the center of the glass rod, keep the cutting device bulky, and cut the glass rod laterally by the cutting force. It is thought that it is impossible to solve the three points of preventing external force from being applied.

In other words, the present invention solves the above three problems at once with respect to the above-mentioned known gas rod cutting device, and when it is applied to the cutting of a glass rod or the like which is a base material for optical fiber spinning, it has a unique requirement for the cutting. (That is, the breaking surface should be as smooth as possible at a right angle to the center of the glass rod, the cutting device should not be bulky, and the cut glass rod should have a horizontal cutting force. It is possible to adequately respond to the requirement that no external force in the direction be applied. Therefore, the present invention has a sufficient technical advancement over the above-mentioned known method and apparatus.

[Brief description of drawings]

FIG. 1 is a front view of the first embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA in FIG. 1, and FIG. 3 is a front view of the second embodiment. In the figure, 1 ... Housing, 2 ... Guide hole, 3 ... Plunger, 3 '... Cam follower, 4 ... Accumulation spring,
5 ... pin, 6 ... L-shaped link, 7 ... cutter, 7 '
...... Blade, 8 ...... quartz glass rod, 9 ...... arm, 10 ...... slot, 11 ...... pin, 12 ...... axis, 13 ...... spiral winding cam,
14 …… Cam surface, 15 …… Radial step surface, 21 …… Electromagnetic casing, 25 …… Pin, 29 …… Arm, 30 slots,
31 …… pin, 32 …… guide sleeve, 33 …… electromagnetic plunger, 33 ′ …… head, 34 …… accumulation spring, 35 …… electromagnetic coil, 36 …… yoke, 37 …… fixed iron core, M ...... It is an electric motor.

Claims (2)

[Claims] 1. A cutting method for continuously cutting a quartz glass rod into a predetermined length by a cutter in its stretching step, wherein a pair of left and right cutters are driven symmetrically about a suspended quartz glass rod, Synchronize the left and right cutters simultaneously and make them collide with the glass rod from the opposite sides at the same time.By the left and right cutters, simultaneously make notches and apply impact forces in opposite directions to the opposite surfaces in the same horizontal plane of the glass rod outer periphery. , Method of cutting quartz glass rod. 2. A plunger urged to one side by a force-accumulating spring, a pair of left and right cutters which are driven in synchronization with each other by the plunger and axially supported by a housing, and the plunger as a force-accumulating spring. A device for cutting a quartz glass rod, comprising: a driving unit that pushes against and stores energy in a power storage spring.